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Drainage Design Report-07.27.2020YELM CREEK APTS —PHASE 2 Drainage Design Report Prepared for: Yelm Creek Lane, LLC 724 Columbia Street NW, #140 Olympia, WA 98501 (360) 943-8060 July 27, 2020 Prepared by: Helena Gubbels, EIT Reviewed by: Steven Hatton, PE HATTON GODAT PANTIER 3910 Martin Way E., Suite B Olympia, WA 98506 (360) 943-1599 Project No: 19-035 Project Name: YELM CREEK APTS —PHASE 2 H:\Office\JOBS\2019\19-035 Yelm Creek Apts Ph.2\PERMIT\Drainage\RPT-Drainage Report 19-035.doc I hereby certify that this Drainage Control Plan for YELM CREEK APTS — PHASE 21 Yelm Creek Lane, Yelm, Washington, has been prepared by me or under my supervision and meets minimum standards of City of Yelm and normal standards of engineering practice. I hereby acknowledge and agree that City of Yelm does not and will not assume liability for the sufficiency, suitability or performance of drainage facilities designed by me. Date Seal 03 �f "%� 24193 ass oNa.LQ G YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 2 TABLE OF CONTENTS I. THURSTUN REGIONAL FACILITY SUMMARY FORM .............................4 II. DRAINAGE REPORT..................................................................................8 Section 1 Project Description................................................................................8 SitePlan...........................................................................................................9 Section 2 Existing Conditions.............................................................................10 ExistingConditions Map.........................................................................................11 Section 4 Wells and Septic Systems..................................................................12 Section5 Fuel Tanks..........................................................................................12 Section 6 Subbasin Description.. some Bud so 0 M a 0 1 as so ME I me be of so Do I me M I of so Do 0 M a so I of BE BE I a be so V 0 a M me be I be 0 1 3 BasinMap............................................................................................................14 Section 7 Floodplain Analysis......... 9 M 1 0 a 0 V I V 0 8 9 s M 9 a 9 V 0 s 0 No me I so so 0 V V ME 0 M a be be so so 1 0 Do I a so so I 1 0 0 1 5 Section 8 Aesthetic Considerations for Facilities...............................................15 Section 9 Facility Selection and Sizing...............................................................16 Section 10 Conveyance System Analysis and Design.........................................21 Section 11 Offsite Analysis and Mitigation...........................................................21 Section12 Utilities................................................................................................21 Section 13 Covenants, Dedications, Easements, Agreements ............................21 Section 14 Other permits or Conditions Placed on the Project..............................21 III. STORMWATER SITE MANAGEMENT PLAN..........................................22 IV. APPENDICES Appendix A Site Development Drawings....................................................... A-1 AppendixB Soil Report................................................................................. B-1 Appendix C Hydraulic Analysis...................................................................... C-1 AppendixD C-SWPPP.................................................................................. D-1 I. I MURSTON REGIONAL FACILITY SUMMARY FORM Complete one for each facility (e.g., detention/retention, coalescing plate filter) on the project site. Attach 8 %" by 11" sketch showing location of facility. Proponent's facility name or identifier (e.g., Pond A): Name of road or street to access facility: Hearings Examiner case number: Development Review Project No./Bldg. Permit No.: Parcel Number(s): To Be Completed By Utility Staff: Utility facility number .............................................. 0 -Known; 1 -Public; 2 -Unknown; 3 -Unassigned Basin and sub -basin, (num, 6ch) ........................... 2ch-Basin; 2ch-Sub-basin; 2ch-Future Responsible jurisdiction, (alpha, 1 ch) ..................... O -Olympia; C -County; T-TU1water; L - Lacey Part 1 -Project Name and Proponent Permeable Pavement w/ Sand Filter 104th Ln SE & Creek Ln SE 64303400202 Project name: YELM CREEK APTS —PHASE 2 Project owner: Yelm Creek Lane, LLC Project contact: Pat Rants Address: 724 Columbia Street NW, #140, Olympia, WA 98501 Phone: (360) 791-5644 Project proponent (if different): Address: Phone: Project engineer: Steven Hatton, PE Firm: HATTON GODAT PANTIER Phone number: (360) 943-1599 YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 4 Part 2 - Project Location Section Township Range 29 17 2E Names and addresses of adjacent property owners: Lockwood, Michael G & Dixie L 16547 103�d Avenue SE, Yelm, WA 98597 Griffin, Helen 16541 103rd Avenue SE, Yelm, WA 98597 Wagers, Jane L & Chris W 10315 Tranquility Lane SE, Yelm, WA 98597 Oliver, Francisco & Bianka 10321 Tranquility Lane SE, Yelm, WA 98597 Lacy, Joanne M 10327 Tranquility Lane SE, Yelm, WA 98597 Black, Christopher C & Shelly M 10335 Tranquility Lane SE, Yelm, WA 98597 Schoolcraft, William R 10339 Tranquility Lane SE, Yelm, WA 98597 Bartlett Triston & Abigayle 10343 Tranquility Lane SE, Yelm, WA 98597 Part 3 -Type of Permit Application Type of permit (e.g., commercial building): Other permits (0): ❑ DOF /W HPA ❑ COE Wetlands ❑ FEMA ❑ Shoreline Management ® Encroachment ❑ Other Residential Plat ❑ COE 404 ❑ DOE Dam Safety ❑ Floodplain ® Rockery/Retaining Wall ® Grading Other agencies (e.g., federal, state, local) that have reviewed or will review this Drainage and Erosion Control Plan: NONE YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 5 Part 4 — Proposed Project Description What stream basin is the project in (e.g., Percival, Woodland)? Zoning :........................ C-2 (Heavy Commercial) Onsite Residential Subdivision: Number of lots ........................................... Average lot size (acres) ............................ Building PermitJCommercial Plat: Patio/Porch paving (acres) ........................ Driveway Surface (acres) .......................... Public roads -including right of way (acres) ............ Public roads asphalt area (acres) .......................... Public roads sidewalk area (acres) ........................ Private roads -including gravel shoulder (acres)..... Onsite impervious surface total (acres) .................. Yelm Creek Part 5 —Pre -Developed Project Site Characteristics Stream through site (Y/N) N Name DNR Type Type of feature this facility discharges to (e.g., lake, stream, intermittent stream, pothole, roadside ditch, sheet flow to adjacent property): NIA Steep slopes—steeper than 10% k ............... Erosion hazard (Y/N)........................................... 100 -year floodplain(Y/N)..................................... Wetlands(Y/N)..................................................... Seeps/springs(Y/N)............................................. High groundwater table (Y/N) .............................. Other.................................................................. N YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 6 Part 6- Facility Description - Permeable Pavement Total area tributary to facility including offsite (acres) .................. 1.43 Total onsite area tributary to facility (acres) ................................. 1.04 Design roof/patio/porch area tributary to facility (acres) .............. 0.18 Design impervious pavement area tributary to facility (acres)... 0.46 Design pervious pavement surface tributary to facility (acres)..... 0.34 Design lawn/landscape area tributary to facility (acres)........,...... 0.43 Design native area tributary to facility (acres).'' ... MGM off me men off SEE 1 0.00 Design pond area tributary to facility (acres)... ... all now me, OEM BOB ago ME 0.00 Design total tributary area to facility (acres) ................................. 1.43 Enter "1" for type of facility Permeable Pavement .................................... 1 Permeable Pavement area (acres) .............. 0.34 Dry pond detention ........................................ Underground detention ................................. Infiltration pond .............................................. Drywell infiltration .......................................... Other.............................. Outlet type (enter "1"for each type present) Filter.......................................................... 1 Oil/water separator ........................................ Singleorifice.................................................a Multiple orifices .............................................. Weir Spillway......................................................... Pump(s)......................................................... Other.........................................................9 Part 7 -Release to Groundwater Design percolation rate to groundwater (if applicable) 20 inches per hour YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 7 II. DRAINAGE REPORT Section 1 Project Description The Yelm Creek Apts —Phase 2 project proposes to develop two 3 -story apartment buildings on 3.01 acres. The project is situated on Tax Parcel Number 64303400202 in the City of Yelm. The site is in Section 29 Township 17 North, Range 2 East, W.M. The zoning for the project is C-2 (Heavy Commercial). See Vicinity Map in Appendix A. Construction will include approximately ±8,040 square feet of roof area, ±14080 square feet of new permeable pavement, ±2580 square feet of impervious pavement, and ±1,053 square feet of sidewalk. Utility improvements include a new 6,000 -gallon septic tank for each new building will tie- in to the STEP system forcemain for the existing apartment complex. Water will be provided by connections to the City of Yelm's system located onsite. Installation of utilities includes site lighting, dry utilities, sewer, and water. The project will require grading, encroachment, building, and utility permits. See Site Plan on page 9. Stormwater design was completed following the guidelines in the 2014 Stormwater Management Manual for Western Washington (2014 SWMMWW). The site contains critical area buffer limits from the Yelm Creek floodplain which confine site disturbance to the west 1.04 acres, with the east 1.97 acres of the parcel remaining undisturbed. The buffer was established by Soundview Consulting in a Wetland and Fish and Wildlife Habitat Assessment Report and Riparian Habitat Buffer Averaging Plan dated December 23, 2019. Stormwater generated from the Phase 2 disturbed area and from the existing Yelm Creek Apts — Phase 1 north parking area (0.33 acres) will sheet flow with shallow concentration onto the new permeable Phase 2 parking area. Currently this portion of the Phase I parking flows onto Phase II. A 64ch sand filter layer under the permeable pavement section will provide treatment before infiltration. The permeable pavement is sized for 100% infiltration of their tributary runoff using WWHM2012 continuous runoff modeling software. All modeling is attached in Appendix C. According to the Geotechnical Engineering Report prepared by South Sound Geotechnical Consulting on October 25,2019, "typical seasonal high groundwater levels may approach within 6 feet (+/-) of the base of the existing storm pond" in the Yelm Creek buffer area and should not adversely impact planned expansion. This existing stormwater pond lies at an approximate elevation of 336, and high groundwater was assumed to reach a maximum elevation of 330 in design. To maintain a minimum 1 foot of separation from groundwater and to achieve the design infiltration rate of 20 in/hr, the minimum porous asphalt surface elevation must be above 333. The project proposes a porous asphalt surface elevation between elevations 340 and 338. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE S SllNfl ZL A8015 -C M3N Lq L Y�l s 1 frl IJ, � V ►iI V L 1 Irl I� V - ss— ss ss— ss— ss— ss— zs— ss ss� Section 2 Existing Conditions The site in its existing condition was previously cleared, now regrown with scattered shrubbery and bushes. The site generally lies at elevations between 341 and 336, sloping towards Yelm Creek perpendicularly with 0.5% to 1% slopes. There is a pocket depression in the east from a previously constructed stormwater pond which has an approximate bottom elevation of 336. This pond serves runoff routed from the Phase 1 parking areas via temporary asphalt drainage swales; and the swales were meant to be demolished in the subsequent Phase 2 for a more permanent conveyance system. On recent site visits during rain events water was found to pond at the border between the two phases, with any overflow channeling shallowly towards the existing stormwater pond. The project proposes to preserve the existing runoff amount into this pond which now lies within a critical area buffer. The project proposes to infiltrate overland flow from the existing north parking area into the new permeable parking area, where it ponds in the existing condition. Overland flow from the existing southern parking area will be collected via a new catch basin located where ponding occurs and piped into the existing drainage swale, and then onto the existing stormwater pond. The project area is bounded by an existing multifamily development to the west, a lumber store to the south, and Yelm Creek to the northeast. See Existing Conditions map on page 11. The site is within the &month time -of -travel zone for a Group A well to the north. Yelm Creek to the northeast forms an adjacent wetland along the northeast boundary. Existing runoff sheet flows from the west to the to the east. Runoff generated from the parking areas of the adjacent multifamily development sheet flows onto the site over the west boundary. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 10 z m 40. 4 aC W W a U .� x a a w J N c� a d z 0 �- A z 0 t� z w Section 3 Soils Report South Sound Geotechnical Consulting completed a Geotechnical Engineering Report dated October 25, 2019. The report found soils consisting of "mixed silt, sand, gravel, with variable organics, cobbles, boulders, and minor debris", and native soil below the fill was considered to be glacial outwash. Groundwater was not observed in any of our field explorations to the maximum depth explored. See Geotechnical Report in Appendix B. The soil survey of Thurston County by the US NRCS indicates the existing soil consists of McKenna gravelly silt loam, 0 to 5% slopes and Spanaway gravelly sandy loam, 0 to 3% slopes. A copy of the NRCS soil map is included in Appendix B. A geotechnical engineering report was prepared by South Sound Geotechnical Consulting dated October 25, 2019. The soil analyses confirm the determination of glacial outwash. Soil analyses from the test pits and borings as part of the geotechnical and stormwater evaluation provide a preliminary design infiltration rate of 23 in/hr, although 20 in/hr was used in final design. Section 4 Wells and Septic Systems Records at Thurston County and the Department of Ecology were searched in order to locate wells and septic systems that may be located within the setback distances from the stormwater pond or ponds. In addition, the Project Engineer, or someone under his direct supervision, has visited the site to verify the presence or absence of wells and septic systems as best can be done visually without trespassing onto other properties. All wells and septic systems found to be located within the setback distances from the stormwater pond or ponds have been shown on the plans. Section 5 Fuel Tanks Records at Thurston County and the Department of Ecology were searched in order to locate the presence of above and below ground fuel storage tanks that may be located within the setback distances from the stormwater pond or ponds. In addition, the Project Engineer, or someone under his direct supervision, has visited the site to verify the presence or absence of fuel tanks as best can be done visually without trespassing onto other properties. No fuel tanks were found to be located within the setback distances from the stormwater pond or within the project area. YELM CREEK APTS -PHASE 2 07.27.2020 rH�t .i Section 6 Subbasin Description For design the threshold discharge area was divided into 3 basins. The Phase 1 basin includes the offsite north parking area from the adjacent multifamily property. The Phase 2 basin includes all onsite areas outside of the Yelm Creek buffer. The Critical Areas basin includes onsite areas within the Yelm Creek and high groundwater hazard buffers. See areas summarized in Table 6.1 and Basin Map in on page 14. Table 6.1 Threshold Discharge Area Subbasin Summary # Basin Native Lawn Roads Roofs Driveways /Parking Sidewalks Permeable Parking Total 1 Phase 1 0.00 0.00 0.00 0.00 0.39 0.00 0.00 3 Phase 2 Critical Areas 0.00 1998 0.44 0.00 0.00 0.00 0.18 0.00* 0.07 0.00 0.02 0.00 0.34 0.00 FOm392 1.98 Total TDA 1.98 0.44 0.00 0.18 0.46 0.02 0.34 3.41 YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 13 �� \ X U4 QO T� Y i l 1p Ile el,wi -h fe it �\r"`ir ell IN UL I — b ISM 00 N P S".It Ci cn a N ,3 --- ----------------------------1------------ ----------------- - - --- _---_=_- ----- -------- - - - Section 7 Floodplain Analysis The Federal Emergency Management Agency prepares maps for all areas within Thurston County, including the incorporated cities therein. Panel # 53067CO362E depicts the areas, if any, subjected to flooding in the vicinity of this proposal. By inspection of this map, the proposed development area appears to be in Zone X, an area of minimal flooding. The areas to remain undeveloped are located within Zone A, subject to the I% annual chance flood. See FEMA firm in Appendix E Section 8 Aesthetic Considerations for Facilities The existing southern drainage swale will be cleared of overgrowth as part of the owner's existing drainage facility maintenance plan. Additional landscaping shall be provided throughout the project in conformance with the approved landscaping and tree restoration plan, as applicable, and as otherwise required by the approving authority. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 15 Section 9 Facility Selection and Sizing This project triggers all nine minimum requirements. See Tables 9.2 and 9.3 for criteria. A review of the Yelm Creek Basin plan yielded no specific requirement for stormwater runoff treatment. The project does not require oil control facilities nor discharge to phosphorus sensitive waters. The project is a multifamily project and is discharges to or near a water body designated for aquatic life. Enhanced treatment applies per the 2014 SWMMWW V-3.5. Enhanced treatment will be provided via BMP T5.15 Permeable Pavements, using additional guidance from LID Technical Guidance Manual for Puget Sound (2012). I-3.4.1 MR1: Preparation of Stormwater Site Plans This project triggers all minimum requirements including the submission of a Stormwater Site Plan. All required documents including the SWPPP and Management Plan will be included with the construction documents. I-3.4.2 MR2: Construction Stormwater Pollution Prevention Plan (SWPPP) A Construction Stormwater Pollution Prevention Plan (C-SWPPP) has been developed to address erosion and sediment control anticipated during construction. A construction NPDES permit will be obtained prior to construction. The C-SWPPP will address all thirteen construction SWPPP elements as required by the Department of Ecology and will be included with the construction documents. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 16 Table 9.1 — Treatment Requirements by Threshold Discharge Area < % Acres of PGPS > % Acres of PGPS < 5,000 ft2 of PGIS > 5,000 ft2 of PGIS Treatment Facilities > 3/ acres conversion to lawn/landscape or > 2.5 acres to pasture. X X X Onsite Stormwater BMPs X X X X This project triggers all nine minimum requirements. See Tables 9.2 and 9.3 for criteria. A review of the Yelm Creek Basin plan yielded no specific requirement for stormwater runoff treatment. The project does not require oil control facilities nor discharge to phosphorus sensitive waters. The project is a multifamily project and is discharges to or near a water body designated for aquatic life. Enhanced treatment applies per the 2014 SWMMWW V-3.5. Enhanced treatment will be provided via BMP T5.15 Permeable Pavements, using additional guidance from LID Technical Guidance Manual for Puget Sound (2012). I-3.4.1 MR1: Preparation of Stormwater Site Plans This project triggers all minimum requirements including the submission of a Stormwater Site Plan. All required documents including the SWPPP and Management Plan will be included with the construction documents. I-3.4.2 MR2: Construction Stormwater Pollution Prevention Plan (SWPPP) A Construction Stormwater Pollution Prevention Plan (C-SWPPP) has been developed to address erosion and sediment control anticipated during construction. A construction NPDES permit will be obtained prior to construction. The C-SWPPP will address all thirteen construction SWPPP elements as required by the Department of Ecology and will be included with the construction documents. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 16 Table 9.2 — Flow Control Requirements by Threshold Discharge Area Flow Control Facilities Onsite Stormwater Management BMPs < 3/ acres conversion to lawn/landscape or < 2.5 acres to pasture. X > 3/ acres conversion to lawn/landscape or > 2.5 acres to pasture. X X < 101000 ft2 of effective impervious area. X > 10,000 ft2 of effective impervious area. X X > 0.1 cfs increase in the 100 -year return frequency flow. X X This project triggers all nine minimum requirements. See Tables 9.2 and 9.3 for criteria. A review of the Yelm Creek Basin plan yielded no specific requirement for stormwater runoff treatment. The project does not require oil control facilities nor discharge to phosphorus sensitive waters. The project is a multifamily project and is discharges to or near a water body designated for aquatic life. Enhanced treatment applies per the 2014 SWMMWW V-3.5. Enhanced treatment will be provided via BMP T5.15 Permeable Pavements, using additional guidance from LID Technical Guidance Manual for Puget Sound (2012). I-3.4.1 MR1: Preparation of Stormwater Site Plans This project triggers all minimum requirements including the submission of a Stormwater Site Plan. All required documents including the SWPPP and Management Plan will be included with the construction documents. I-3.4.2 MR2: Construction Stormwater Pollution Prevention Plan (SWPPP) A Construction Stormwater Pollution Prevention Plan (C-SWPPP) has been developed to address erosion and sediment control anticipated during construction. A construction NPDES permit will be obtained prior to construction. The C-SWPPP will address all thirteen construction SWPPP elements as required by the Department of Ecology and will be included with the construction documents. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 16 -3A3 M 3 Source Control of Pollution Permanent source control BMPs are used to prevent stormwater from coming in contact with pollutants and are used as a cost-effective means of reducing pollutants in stormwater. The selection of permanent source control BMPs is based on the activities likely to occur on the site and the pollutants associated with those activities. Chapter 2, Volume IV of the 2014 Stormwater Management Manual for Western Washington has been reviewed. Applicable Source Control BMP's can be found in the Source Control Plan located in Section IV of this document. There are two types of source control BMPs: operational and structural. Operational source control BMPs are non-structural practices that prevent or reduce pollutants from entering stormwater. Structural source control BMP's are physical, structural or mechanical devices or facilities intended to prevent pollutants from entering stormwater. EXAMPLES OF OPERATION SOURCE CONTROL BMPS A. Form a Pollution Prevention Team that will be responsible for inspecting the stormwater systems and potential pollution sources, operation and maintenance of stormwater systems and enforcement of preventing pollution discharges into the stormwater systems. The team will also be the emergency response team. B. Good housekeeping includes containing and cleaning up spills on any exposed soils, vegetation or paved areas; sweeping paved surfaces; cleaning pollutants and debris from all BMPs regularly; and making repairs to containment systems, leaks and other sources that could pollute the drainage system. C. Preventative Maintenance 1. Provide recycling or post signs to recycle materials such as oils, solvents and wood waste to the maximum extent practicable. 2. Prevent the discharge of unpermitted liquids and solids into the storm drainage system. 3. Use drip pans to collect leaks and spills from vehicles and equipment. 4. Store liquids in steel or plastic containers that are rigid, durable, corrosion resistant, non-absorbent, water tight, rodent -proof and equipped with a close -fitting cover. D. Spill Prevention and Cleanup 1. Stencil warning signs at stormwater catch basins and drains — "Dump no waste". 2. Immediately stop, contain and clean up all spills. 3. Contact appropriate local agency (Fire Department, City of Olympia Public Works, Health Department or Department of Ecology) for assistance and guidance. 4. Keep spill containment and clean up kits readily accessible. E. Employee training shall include identification of pollutant sources, understanding pollutant control measures, spill response procedures and acceptable material handling practices. F. Inspections YELM CREEK APTS -PHASE 2 07.27.2020 PACit 1 I 1. Inspections should occur a minimum of twice a year, once during October 1 through April 30 and once during May 1 through September 30. Verify that BMPs are being implemented adequately and make note of any observations of floating materials, suspended solids, oil and grease, discoloration, turbidity or odor in stormwater discharges. Check pH as needed. 2. Determine whether there are unpermitted non-stormwater discharges to the drainage system and eliminate discharges. 5. Retain the following reports for at least three years: i. Visual inspection reports. ii. Reports on spills of oil or hazardous substances greater than Reportable Quantities that cause a violation of the State of Washington's Water Quality Standards, Contact Department of Ecology and ask for an oil spill operations or a hazardous waste specialist to determine if a spill is a substance of a Reportable Quantity, Southwest Region Dept. of Ecology: (360) 407-6300 or call 911. EXAMPLES OF STRUCTURAL SOURCE CONTROL BMPS A. Enclosing and/or covering pollutant sources, i.e., within a building or other enclosure, a roof over storage and working areas, a temporary tarpaulin, etc. B. Physically segregating the pollutant source to prevent contact with uncontaminated stormwater that runs on the site from surrounding areas. The owner will receive a copy of the Pollution Source Control Program as found in the Stormwater Maintenance Plan in Section IV below. The Source Control Program describes Best Management Practices (BMPs) for residential properties. MR4: Preservation of Natural Drainage Systems and Outfalls Natural drainage patterns shall be maintained and discharges from the project shall occur at the natural location. The project proposes to restrict development to those areas outside of the critical area buffer for Yelm Creek, Yelm Creek and its associated floodplain will drain in the natural condition. The runoff from the onsite developed area and from the offsite existing pavement will be infiltrated through the project site's underlying, rapid -draining soils via permeable pavement. Roof runoff from Building #7 and Building #6 will be collected via roof downspouts and conveyed to the permeable pavement underdrain. Current runoff from the adjacent property's north parking area drains to the pond at the paved boundary shared with the project site to infiltrate in place or interflow towards Yelm Creek. The south parking area's runoff is collected at a paved ridge at the project's west boundary and flows shallowly overland into an existing drainage swale along the southern boundary line then on to a previously constructed storm pond in the critical area buffer. There is no evidence of other ponding onsite. The permeable pavement has been designed to infiltrate 100% of tributary runoff. See Section 2 — Existing Conditions for a detailed description of the existing drainage pattern and preservation. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 18 I-3.4.5 MR5: Onsite Stormwater Management Projects shall employ On-site Stormwater Management BMPs in accordance with the following project thresholds, standards and lists to infiltrate, disperse, and retain stormwater runoff onsite to the extent feasible without causing flooding or erosion impacts. This project triggers Minimum Requirements #1 through #9 and therefore must meet the requirements in Table 1-2.5.1 in the 2014 SWMMWW. To satisfy the requirements in Table 1-2.5.1 this project will meet the LID Performance Standard and implement BMP T5.13: Post -Construction Soil Quality and Depth. The LID Performance Standard states that stormwater discharge rates shall match developed discharge durations to pre -developed durations for the range of pre -developed discharges from 8% of the 2 -year peak flow to 50% of the 2 -year peak flow. This project will infiltrate 100% of the runoff onsite, therefore meeting the requirements of the LID Performance Standard. The project will also implement BMP T5.13, Post -Construction Soil Quality and Depth, in all new lawn and landscaped areas. Roof area runoff from Building #7 and Building #6 will be collected via roof drains and conveyed to the onsite permeable pavement underdrain. I-3.4.6 MR6: Runoff Treatment Projects in which the total pollution generating hard surface is 5,000 square feet or more in a threshold discharge are required to provide treatment. A review of the Yelm Creek basin plan did not specify any enhanced or phosphorus treatment requirements. The project is a multifamily project, which triggers the requirement for enhanced treatment. After preliminary conversations with the City of Yelm, the project proposes to treat runoff with the inclusion of a 6" sand filter layer beneath the permeable pavement section. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 19 I-3.4.7 MR7: Flow Control The project is not in a flow control exempt region and therefore is required to provide flow control. To provide flow control the project proposes the use of permeable pavement. The permeable pavement section was sized using WWHM2012 v.2.14 to infiltrate 100% of tributary runoff and shows no sign of ponding. Sizing of facilities included onsite areas bounded by the critical area buffer as well as the existing impervious pavement runoff from the adjacent apartment complex flowing to the permeable pavement. See Table 9.3 for a summary of modelling areas. To size the permeable pavement: 1) The permeable pavement surface area was totaled, and an approximate pavement length of 270 feet was obtain by measurement to calculate an approximate width. a. Surface Area = 14,979 square feet b. Pavement Length = (14,979 square feet) / (270 feet) = 55.47 55.5 feet 2) A pavement section was determined using the SMMWW a. Porous Asphalt = 4 inches, min. b. Choker Course (#57) = 2 inches, typ. c. Base Course (Permeable ballast) = 12 inches, minimum for vehicular loading d. Sand Filter Layer = 6 inches, as recommended in conversation with City of Yelm 3) Soil analysis from the report composed by South Sound Geotechnical Consulting on October 25, 2019 provides a preliminary design infiltration rate of 23 in/hr reduced to a maximum infiltration rate of 20 in/hr for our purposes, qualifying the project for the use of permeable pavement. A design infiltration rate as low as 1.5 in/hr was tested in WWHM modelling to ensure no ponding would occur, and to account for potential groundwater mounding beneath the pavement section. Using this BMP, the project expects a reduction in the 100 -year storm peak, noted in Table 9.3. For the detailed WWHM modelling report and spreadsheet area totals, refer to Appendix C. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 20 Table 9.3 —Facilities Area Summary (All areas measured in acres) Onsite Offsite To Pervious Pavement Total Non -Pollution -Generating Impervious Surface (NPGIS) 0.20 0.00 0.20 Total Pollution Generating Impervious Surface (PGIS) 0.06 0.39 0.45 Total Pollution Generating Permeable Surface (PGPS) 0.34 0.00 0.34 Native Vegetation Converted to Lawn/Landscape (Offsite areas are existing lawn/landscaping) 0.44 0.00 0.44 Native Vegetation Not Converted (Offsite areas are existing/remaining forest) 1.98 0.00 0.00 Increase (Decrease) in 100 -year Storm Peak (cfs) - - (0.0662) YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 20 I-3.4.8 MR8: Wetlands Protection The project does not propose the release of any stormwater discharge to any wetlands. Yelm Creek forms a wetland in its buffer area. I-3.4.9 MR90 Operation and Maintenance A Stormwater Facility Maintenance Program consistent with the provision in Volume IV shall be provided for the proposed stormwater facilities and BMPs. This plan can be found in Section IV. Section 10 Conveyance System Analysis and Design Stormwater design for this project relies on overland flow and an existing swale. The existing Swale along the southern border of the site will be cleared of overgrowth as part of Phase 1's existing maintenance plan. The catch basin and PVC pipe conveyance into this swale have been sized to accommodate the flow into the existing channel. Section 11 Offsite Analysis and Mitigation The project does not propose the release of any stormwater discharges offsite. Section 12 Utilities Utilities will be installed according to the standards set forth by the City of Yelm and are shown on the plans. Stormwater structures, pipes and facilities will be installed to ensure no conflict with the proposed utilities. Section 13 Covenants, Dedications, Easements, Agreements All stormwater facilities located on private property shall be owned, operated and maintained by the property owners, their heirs, successors and assigns. The property owners shall enter into an agreement with the governing body, a copy of which agreement is included in Section IV of this report. The agreement requires maintenance of the stormwater facilities in accordance with the maintenance plan provided and shall grant easement for access to the governing body to inspect the stormwater facilities. The agreement also makes provisions for the governing body to make repairs, after due notice is given to the owners, if repairs are necessary to ensure proper performance of the stormwater system and if the owners fail to make the necessary repairs. The cost of said repairs shall be borne by the property owners, their heirs, successors and assigns. Section 14 Other permits or Conditions Placed on the Project No other permits are known to be required for this project. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 21 III. STORMWATER SITE MANAGEMENT PLAN YELM CREEK APTS -PHASE 2 July 27, 2020 YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 22 TABLE OF CONTENTS I. MAINTENANCE AGREEMENT....................................................... 24 II. STORMWATER FACILITY MAINTENANCE GUIDE ...................... 30 Introduction.............................................................................................................31 Your Stormwater Facilities.....................................................................................32 FacilityKey.............................................................................................................33 SitePlan.................................................................................................................34 QuickList. . Is as a m 9 0 a 9 a 0 a I v v v 0 m m a a 0 m a m 1 0 a 0 1 v v I m I m a 0 1 m I a 9 6 0 6 4 35 MaintenanceChecklists.........................................................................................36 ResourceListing....................................................................................................39 LogSheet...............................................................................................................40 III. POLLUTION SOURCE CONTROL PROGRAM .............................. 42 Purpose..................................................................................................................42 Recommended Pollution Control Practices...........................................................42 Household Hazardous Wastes...............................................................................42 Pesticides and Fertilizers.......................................................................................47 References.............................................................................................................49 IV. GLOSSARY......................................................................................50 I. MAINTENANCE AGREEMENT YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 24 COMMERCIAL/INDUSTRIAL AGREEMENT TO MAINTAIN STORMWATER FACILITIES AND TO IMPLEMENT A POLLUTION SOUCE CONTROL PLAN BY AND BETWEEN Yelm Creek Lane, LLC HEIRS, SUCCESSORS, OR ASSIGNS (HEREINAFTER " Owner ") AND City of Yelm, Washington HEREINAFTER "JURISDICTION") The upkeep and maintenance of stormwater facilities and the implementation of pollution source control best management practices (BMPs) is essential to the protection of water resources. All property owners are expected to conduct business in a manner that promotes environmental protection. This Agreement contains specific provisions with respect to maintenance of stormwater facilities and use of pollution source control LEGAL DESCRIPTION: Whereas, the Owner has constructed improvements, including but not limited to, buildings, pavement, and stormwater facilities on the property described above. In order to further the goals of the Jurisdiction to ensure the protection and enhancement of Jurisdiction's water resources, the Jurisdiction and the Owner hereby enter into this Agreement. The responsibilities of each party to this Agreement are identified below. The Owner SHALL: (1) Implement the stormwater facility maintenance program included herein as Attachment "A." (2) Implement the pollution source control program included herein as Attachment (3) Maintain a record (in the form of a log book) of steps taken to implement the programs referenced in (1) and (2) above. The log book shall be available for inspection by Jurisdiction staff during normal business hours. The log book shall catalog the action taken, who took it, when it was done, how it was done, and any problems encountered or follow-on actions recommended. Maintenance items ("problems") listed in Attachment "A" shall be inspected on a monthly or more frequent basis as necessary. The Owner is encouraged to photocopy the individual checklists in Attachment A and use them to complete its monthly inspections. These completed checklists would then, in combination, comprise the monthly log book. (4) Submit an annual report to the Jurisdiction regarding implementation of the programs referenced in (1) and (2) above. The report must be submitted on or before May 15 of each calendar year and shall contain, at a minimum, the following: (a) Name, address, and telephone number of the business, the person, or the firm responsible for plan implementation, and the person completing the report. (b) Time period covered by the report. (c) A chronological summary of activities conducted to implement the programs referenced in (1) and (2) above. A photocopy of the applicable sections of the log book, with any additional explanation needed, shall normally suffice. For any activities conducted by paid parties not affiliated with the Owner include a copy of the invoice for services. (d) An outline of planned activities for the next year. THE JURISDICTION SHALL: (1) Provide technical assistance to the Owner in support of its operation CIHd maintenance activities conducted pursuant to its maintenance and source control programs. Said assistance shall be provided upon request, and as Jurisdiction time and resources permit, at no charge to the Owner (2) Review the annual report and conduct a minimum of one (1) site visit per year to discuss performance and problems with the Owner (3) Review this agreement with the Owner and modify it as necessary at least once every three (3) years. REMEDIES: (1) If the Jurisdiction determines that maintenance or repair work is required to be done to the stormwater facility existing on the Yelm Creek Apartments property, the Jurisdiction shall give the owner of the property within which the drainage facility is located, and the person or agent in control of said property, notice of the specific maintenance and/or repair required. The Jurisdiction shall set a reasonable time in which such work is to be completed by the persons who were given notice. If the above required maintenance and/or repair is not completed within the time set by the Jurisdiction, written notice will be sent to the persons who were given notice stating the Jurisdiction's intention to perform such maintenance and bill the owner for all incurred expenses. The Jurisdiction may also revoke stormwater utility rate credits for the quality component or invoke surcharges to the quantity component of the bill if required maintenance is not performed. (2) If at any time the Jurisdiction determines that the existing system creates any imminent threat to public health or welfare, the Jurisdiction may take immediate measures to remedy said threat. No notice to the persons listed in (1), above, shall be required under such circumstances. (3) The owner grants unrestricted authority to the Jurisdiction for access to any and all stormwater system features for the purpose of performing maintenance or repair as may become necessary under Remedies (1) and/or (2). (4) The persons listed in (1), above, shall assume all responsibility for the cost of any maintenance and for repairs to the stormwater facility. Such responsibility shall include reimbursement to the Jurisdiction within 30 days of the receipt of the invoice for any such work performed. Overdue payments will require payment of interest at the current legal rate for liquidated judgments. If legal action ensues, any costs or fees incurred by the Jurisdiction will be borne by the parties responsible for said reimbursements. (5) The owner hereby grants to the Jurisdiction a lien against the above-described property in an amount equal to the cost incurred by the Jurisdiction to perform the maintenance or repair work described herein. This Agreement is intended to protect the value and desirability of the real property described above and to benefit all the citizens of the Jurisdiction. It shall run with the land and be binding on all parties having or acquiring from the Owner or their successors any right, title, or interest in the property or any part thereof, as well as their title, or interest in the property or any part thereof, as well as their heirs, successors, and assigns. They shall inure to the benefit of each present or future successor in interest of said property or any part thereof, or interest therein, and to the benefit of all citizens of the Jurisdiction. Signed this day of , 20 Owner Owner STATE OF WASHINGTON ) ) ss COUNTY OF THURSTON ) On this day and year below, personally appeared before me to me known to be the of and who executed the within and foregoing instrument and acknowledged that he/she signed the same as his/her own free and voluntary act and deed on behalf of themselves or as corporate officers of the named corporation with the full authority, for the uses and purposes herein mentioned. Given under my hand and seal this STATE OF WASHINGTON ) ss COUNTY OF THURSTON ) Notary Public in and for the State of Washington, residing at My commission expires: On this day and year below, personally appeared before me to me known to be the Public Works Director of the City of Yelm, a Municipal Corporation, who executed the foregoing instrument and acknowledged the said instrument to be the free and voluntary act and deed of said Municipal Corporation for the uses and purposes therein mentioned and on oath states he is authorized to execute the said instrument. Given under my hand and seal this _ day of Notary Public in and for the State of Washington, residing at My commission expires: Attachment "A" Stormwater Facilities Maintenance Program YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 30 II. STORMWATER FACILITY MAINTENANCE GUIDE Introduction What Is Stormwater Runoff? When urban and suburban development covers the land with buildings, streets and parking lots, much of the native topsoil, duff, trees, shrubs and grass are replaced by asphalt and concrete. Rainfall that would have soaked directly into the ground instead stays on the surface as stormwater runoff making its way into storm drains (including man-made pipes, ditches or swale networks), stormwater ponds, surface and groundwater and, eventually, to Puget Sound. What Is a Storm Drain System and How Does It Work? The storm drain system for most developments includes measures to carry, store, cleanse and release the stormwater. Components work together to reduce the impacts of development on the environment. Impacts can include flooding that results in property damage and blocked emergency routes, erosion that can cause damage to salmon spawning habitat and pollution that harms fish and/or drinking water supplies. The storm drain system provides a safe method to carry stormwater to the treatment and storage area. Swales and ponds filter pollutants from the stormwater by physically settling out particles, chemically binding pollutants to pond sediments and biologically converting pollutants to less harmful compounds. Ponds also store treated water, releasing it gradually to a nearby stream or to groundwater. What Does stormwater Runoff Have to Do With Water Quality? stormwater runoff must be treated because it carries litter, oil, gasoline, fertilizers, pesticides, pet wastes, sediments and anything else that can float, dissolve or be swept along by moving water. Left untreated, polluted stormwater can reach nearby waterways where it can harm and even kill aquatic life. It can also pollute groundwater to the extent that it requires treatment before it is suitable for drinking. Nationally, stormwater is recognized as a major threat to water quality. Remember to keep everything out of stormwater systems except the rainwater they are designed to collect. stormwater Facilities Different types of ponds are designed for different purposes. For example, wet ponds primarily provide treatment of stormwater. Dry ponds or retention ponds are designed to provide storage for stormwater and allow for its gradual release downstream or into the ground. Who Is Responsible for Maintaining stormwater Facilities? All stormwater facilities require maintenance. Regular maintenance ensures proper functioning anA preserves visual appeal. This stormwater Facility Maintenance Guide was designed to explain how stormwater facilities work and provide user-friendly, straightforward guidance on facility maintenance. You are responsible for regularly maintaining privately owned ponds, catch basins, (ELM CREEK APTS -PHASE 2 07.27.2020 PAGE 31 pipes and other drainage facilities on your property. Stormwater facilities located in public rights-of- way are maintained by local governments. How to use the Stormwater Facility Maintenance Guide This Maintenance Guide includes a Site Plan specific to your development and a Facility Key that identifies the private stormwater facilities you are responsible for maintaining. A "Quick List" of maintenance activities has also been included to help you identify the more routine needs of your facility. Included in This Guide • Comprehensive Maintenance Checklists that provide specific details on required maintenance • Pollution Prevention Tips that list ways to protect water quality and keep storm drain systems functioning smoothly • Resources to provide more information and technical assistance A Regional Approach to Stormwater Management The Cities of Lacey, Olympia and Tumwater together with Thurston County are taking steps to educate and involve area residents in water quality issues and stormwater management. Stormwater runoff is a widespread cause of water quality impairment and stream degradation. The jurisdictions are working together with residents, businesses, community groups and schools to address this problem. This guide focuses on providing information on ways that you can reduce stormwater impacts through pollution prevention and proper facility maintenance. Your Stormwater Facilities This section consists of two parts that are to be used together: the Facility Key and the Site Plan. Review the site plan and identify the numbers denoting a feature of the system. Then check the facility key for the feature type and checklist name. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 32 Facility Key The stormwater facility in your neighborhood is comprised of the following elements: YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 33 Type "of Feature and Checklist Name Location on Site Plan Permeable Pavement 1 PVC Pipe - Solid 2 PVC Pipe - Perforated 3 Catch Basin 4 YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 33 of for to LID r/�1 �V1 1z W /, i'i / #a I --or Nf OEM( toU // I� III MI IS IIII IIII III II! r ',,, / i! y � II,� I16�II� :i� Nllll £III IIII I III s lili��ll IIP 9 i* p Y•I Jrul�yyl 41 lahl! 4 J Iryl a �I . I lql II II I I or�I 9liliip Illq"171 ! wlll"IIII"I ISI 3 i_i ' f III III III III III � I I I I Irll j q l II� �& II (IIII yI u 11111 I - � w low �.1.� +/ 'i' i' I I � I I�I��III Irlls I��I. L: I�I II IIII . IIII Il�llligla� IIIIaIVh�l71 II! ii/ �� I!III I,� ladsI QI �� a I !I III !II it � agilll�ll�l (IIII VIII �" /+ i' rll llliill, IIIIIIi�I� j I�I III III I III ¢I w�/I�dIIV��InyMilh��ll�l! M .i / ` d. IIIA �II Il !IIII ISI w dift,I i UOF I�11 V` In�r ,yb C' ,'� 11 1 rg ��1 ��.;✓r' r � .t__i� �, ry W M� �h 4� �y�A' �i � or ��I / r,�?� �Vr Wj r No op o > oofi \ .� �d d m CI of AL 'fir) No It _ of °lilt 4r) of A 1 Y ��71 -•� M 4/ IhI �k 1 �r qq� +- II -- � 5 t o` n u _ n g Mfl oo �a \' I1 I IC I's c , ... Lon UM dam' 3.90 fa JO N —� V) .` W_ ____. _______- Quick Llst The following is an abbreviated checklist of the most common types of maintenance required. Please go over this checklist after heavy rains. The list represents minimum maintenance to be performed and should be completed in conjunction with the other checklists for an effective maintenance program. ❑ Inspect catch basin grates to see that they are not clogged or broken. Remove twigs, leaves or other blockages. Contact the local jurisdiction to replace the grate if it is broken. ❑ Inspect inlet and outlet pipes for blockages. Clear all blockages. ❑ Inspect filter strip, swale and pond walls for erosion or caved in areas. ❑ Inspect riprap (rocks) at the inlets and outlets of culverts and other pipes. If they are silted in or eroded away, replace them. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 35 Maintenance Checklists The Maintenance Checklists in this packet are for your use when inspecting the stormwater facilities on your property. This packet has been customized so that only the checklists for your facilities are included. If you feel you are missing a checklist, or you have additional facilities not identified or addressed in this packet, please contact your local jurisdiction. The checklists are in tabular format for ease of use. Each describes the area to inspect, inspection frequency, what to look for and what action to take. A log sheet is included toward the end of the chapter to help you track maintenance of your storm drainage system. Although it is not intended for the maintenance survey to involve anything too difficult or strenuous, there are a few tools that will make the job easier and safer including: • A flashlight • A long pole or broom handle • Some kind of pry bar or lifting tool for pulling manhole and grate covers • Gloves A resource list is included in the next chapter. There you will find the phone numbers of the agencies referenced in the tables, as well as the contractors and consultants who designed and constructed your facilities. SAFETY WARNING: In keeping with OSHA regulations, you should never stick your head or any part of your body into a manhole or other type of confined space. When looking into a manhole or catch basin, stand above it and use the flashlight to help you see. Use a long pole or broom handle to check sediment depths in confined spaces. NO PART OF YOUR BODY SHOULD BREAK THE PLANE OF THE OPEN HOLE. 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Make copies of this page; use a fresh copy for each inspection. The completed sheets will serve as a record of maintenance activity and will provide valuable information about how your facilities are operating. Log sheets should be kept in a dry, readily accessible place. INSPECTION DATE: PERFORMED BY: PHONE NUMBER: ADDRESS: CITY, POSITION ON HOA: ST, ZIP: SERVATINS PART •F FACILITY (LIST ••-• • OF ACTIONINSPECTED ACTIVITIES) ACTION YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 44 YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 44 Attachment "B" Pollution Source Control Program YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 45 III. POLLUTION SOURCE CONTROL PROGRAM Purpose Many products and practices commonly used in and around the home are hazardous to both the environment and us. Many of these products can end up in our stormwater systems and groundwater. This document gives alternatives, where possible, for those types of products and practices. The Best Management Practices (BMPs) described here include "good housekeeping" practices that everyone can use. Recommended Pollution Control Practices It has been said that the average home today contains more chemicals than the average chemical lab of 100 years ago. When many of these chemicals are used industrially, they can be subject to various health and safety standards; yet these same substances are used freely and often carelessly in our homes. The BMPs in this section are divided into two categories: Household Hazardous Wastes and Pesticides. Each section includes information on available alternatives. Household Hazardous Wastes Many of the cleaning agents, solvents, polishes, etc, commonly used in the home are considered hazardous. These products may be toxic, corrosive, reactive, flammable and/or carcinogenic. It is critical that these products are handled with care and are disposed of properly. A list of common household hazardous materials is presented in Table 1. In addition, many hazardous household chemicals persist for long periods of time in the environment. Manufacturers may truthfully state that a product is "biodegradable"; most products are biodegradable, but what is important is the rate at which they are broken down and the products into which they are broken down. The term "biodegradable" on its own is misleading at best, unless the product is rapidly degraded into harmless substances. It is important to note here that the term "biodegradable" currently has no legal definition in this state. This means that any product can use this term according to the manufacturer's own definition. This definition may not be at all similar to the consumer's perception. The following ideas will help you reduce the risks of stormwater and groundwater contamination from many household products. Household Product Management 1. Read product labels before purchasing. Toxic product labels will carry many warnings. Either bypass such products or purchase in small quantities. If you cannot use the entire product, try to give it away instead of disposing of it. Thurston County periodically facilitates product exchanges for leftover paints and other hazardous wastes. Call the Thurston County Health Department at (360) 7544111 for more information. YELM CREEK APTS - PHASE 2 07.27.2020 PAGE 46 2. Buy only those detergents that contain little or no phosphorus. Phosphorus can cause algae blooms if washed into lakes or streams. Most detergents that are low in phosphates or phosphate free are labeled as such. 3. Use no more than the manufacturer's suggested amount of any cleanser. More is not necessarily better. 4. Products such as oven cleanser, floor wax, furniture polish, drain cleaners and spot removers often contain toxic chemicals. Buy the least toxic product available or use a non- toxic substitute if one can be found. For example, ovens can be cleaned by applying table salt to spills then scrubbing with a solution of baking soda and water. Table 2 lists substitutes for many commonly used household,products. If it is necessary to use a product that contains toxic chemicals, use the product only as directed. Do not combine products, as they may become more dangerous when mixed (e.g., mixing chlorine bleach and ammonia produces dangerous gases). Use eye protection and rubber gloves as appropriate. Contact the Hazardous Substance Hotline at 1-800-633-7585 if you have any questions regarding disposal of a product or empty container. The County has both hazardous waste collection days and permanent facilities where residents can bring hazardous wastes. Call the Thurston County Health Department at (360) 754-4111 for more information. 5. Chemicals left over from activities such as photography and auto repair are hazardous and should not be flushed down the sink. This is especially important if your home is hooked up to a septic system. Toxic chemicals can kill the beneficial bacteria in the tank used to treat sewage and can pollute water supply wells. 6. Be sure all containers are clearly labeled. 7. Common batteries (not automobile) are one of the largest sources of heavy metals (such as lead, nickel, cadmium and mercury) found in landfills. Instead of throwing them away, dispose of them at a hazardous waste collection site. Automotive Usage, Care and Maintenance From a waste management standpoint, automobile maintenance is best done by professionals at facilities designed to handle, store and dispose of the waste products properly. Many of these facilities do an excellent job of dealing with waste oils, antifreezes, other fluids, batteries and tires. They often charge a small fee to cover the added expenses, but it's worth it. However, if you repair your car at home, please consider these helpful tips I. Cars should be serviced regularly. Leaky lines or valves should be replaced. 2. Dumping oil, degreasers, antifreeze and other automotive liquids into a stream or a storm drain violates city, county and state laws or ordinances. Do not dump them onto the ground because they will end up in stormwater runoff or in groundwater. Do not use oil to reduce dust levels on unpaved areas. Instead, recycle used oil and antifreeze. Keep them in separate containers. Call the Recycling Hotline at 1 -800 -RECYCLE or call the Thurston County Health Department for the location of the nearest recycling center, or inquire YELM CREEK APTS - PHASE 2 07.27.2020 PAGE 47 whether your local automotive service center recycles oil. Some may also take used oil fiIters. 3. Wrap empty oil or antifreeze containers in several layers of newspaper, tie securely and place in a covered trashcan. Antifreeze is sweet tasting but poisonous to people, fish, pets and wildlife. 4. Sweep your driveway instead of hosing it down. Fluids and heavy metals associated with automobiles can build up on driveway surfaces and be washed into local surface or groundwater when driveways are hosed down. 5. When washing vehicles, do so over your lawn or where you can direct soapsuds onto the lawn or another vegetated area to keep the soap from washing into the storm drain system or local surface water. Your stormwater pond cannot cleanse soapy water. 6. Small spills of oil and other fluids can be absorbed with materials such as kitty litter or sawdust. Wrap the used absorbent and any contaminated soil in a plastic bag and place in the garbage. If a spill reaches surface water, you must notify the nearest regional office of the Department of Ecology immediately! The Southwest Regional Office phone number is (360) 407-6300, or call 911. There are fines for failure to notify the appropriate agency when a spill occurs. 7. De-icing chemicals (various types of salt) can harm concrete less than three years of age, burn vegetation and be corrosive to cars and other metal objects. De-icing chemicals and their additives can be toxic. (Cyanide is formed from the breakdown of a common ant! - caking agent used in de-icing chemicals.) Urea salts are an alternative to other types of salt de-icers, but great care must be used in applying them. These salts contain large quantities of nitrogen, which can severely burn plants and encourage algae growth if over -applied. The use of these chemicals should be minimized or avoided. Instead, shovel walks clear and apply a dusting of sand to improve footing. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 48 Table 1 Hazardous Household Substances List Auto, Boat and Equipment Source: Guidelines for Local Hazardous Waste Planning, Ecology, No. 87-18 1987, Repair and Remodeling Cleansing Agents Maintenance Batteries Adhesives, glues, cements Oven cleaners Waxes and cleansers Roof coatings, sealants Degreasers and spot removers Toilet, drain and septic tank Paints, solvents and thinners Caulking and sealants cleaners Additives Epoxy resins Polishes, waxes and strippers Deck, patio and chimney Gasoline Solvent -based paints cleaners Flushes Solvents and thinners Solvent cleaning fluids Auto repair materials Paint removers and strippers Motor oil Diesel oil Antifreeze Pesticides Hobby and Recreation Miscellaneous Insecticides Paints, thinners and solvents Ammunition Fungicides Chemicals (photo and pool) Asbestos Rodenticides Glues and cements Fireworks Molluscicides Inks and dyes Wood preservatives Glazes Moss retardants Chemistry sets Herbicides Bottled gas Fertilizers White gas Charcoal starter fluid YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 49 Table 2. Non- or Less Toxic Alternatives to Toxic Products Hazardous Product YELM CREEK APT0 Alternative(s) Air fresheners Set out a dish of vinegar; simmer cinnamon or cloves in water; set out herbal bouquets or potpourri in open dishes; burn scented candles. Bleach Borax or oxygen bleaches or reduce bleach by'/ and add '/4 1/2 C baking soda; line dry clothes. Brass polish Worcestershire sauce Chrome polish Apple cider vinegar; a paste of baking soda and water; a lemon Coffee pot cleaner Vinegar; remove coffee stains with moist salt paste, Copper cleaner Mixture of lemon juice and salt or tomato catsup. Drain cleaner Use a plunger followed by'/2 C baking soda mixed with '/z C vinegar. Let sit 15 minutes; pour into drain followed by 2 qt. boiling water. Furniture polish Linseed, olive or almond oils; a mixture of 3 parts olive oil to 1 part white vinegar; a mixture of 1 T lemon oil and 1 pint mineral oil Garbage disposal deodorizer Lemon rind or baking soda. Glass cleaner Mixture of 2 T vinegar and 1 quart water Grease remover Paste of borax and water on damp cloth Ink stain remover Spray with non -aerosol hairspray before washing. Laundry soap Borax; baking soda; washing soda Linoleum floor cleaner Mixture of 1 C white vinegar and 2 gallons water Mildew remover Equal parts vinegar and salt Mothballs Cedar chips or blocks; dried tansy, lavender or peppercorns Oils ills Kitty litter; sawdust Oil stain remover White chalk rubbed into stain prior to washing Oven cleaner Cover fresh spills with salt; scrape off after the oven cools. A soda water solution will cut grease. Paint ammonia on spills with a paintbrush, then rinse off. Paint brush softener Hot vinegar Paint stripper Use mechanical sanding instead of chemical strippers. Paint or grease remover Wear gloves or try baby oil Pet odor remover Cider vinegar Pitch or sap remover Butter, margarine or vegetable shortening. Porcelain stain remover Baking soda Refrigerator deodorizer Oen box of baking soda Rug/carpet cleaner (General) Use a soap -based non -aerosol rug shampoo; vacuum when dry. (Spots) Pour club soda or sprinkle cornmeal or cornstarch on the rug; let sit for at least 30 minutes; vacuum. Rust remover Lemon juice and sunlight Rusty bolt remover Carbonated beverage Scorch mark remover Grated onion Scouring powder Baking soda or non -chlorine scouring powder. Silver polish Soak silver in warm water with 1 T soda, 1 T salt and a piece of aluminum foil. Stainless steel polish Mineral oil Toilet bowl cleaner Paste mixture of borax and lemon juice Tub and tile cleaner % C soda and '/z C white vinegar mixed with warm water Upholstery sot remover Club soda Water mark remover Toothpaste -PHASE 2 07.27.2020 PAGE 50 Pesticides and Fertilizers Pesticides and fertilizers are commonly used by homeowners in their quest for bigger, healthier plants and greener, lusher lawns. These chemicals are often overused and misapplied. These chemicals are easily introduced into stormwater runoff and can cause algae blooms (fertilizers) or kill off aquatic organisms (pesticides). Fertilizer. Management Fertilizing a lawn can be done in an environmentally sensitive manner. Here are some ideas. 1. Before fertilizing, test your soil's pH by using a readily available kit or through tests provided by WSU Cooperative Extension. Use only the recommended amount of fertilizer and any soil amendments, such as lime, that are recommended in your test results. 2. Use fertilizers that are appropriate for your area and for the types of plants you are growing. Work the fertilizer into the soil directly around the plant's drip line. By incorporating the fertilizer in the soil, there will be less likelihood of contaminated runoff. Contact the Thurston Conservation District for more information. 3. Water before fertilizing. Water enough to dampen the ground thoroughly but not enough to cause surface runoff. Dampening the soil prevents fertilizer from being washed from the surface of dry soil in the first rain or watering after application. 4. Many soils can benefit from the use of organic fertilizers such as compost or peat. Not only do these substances add nutrients to soil; they also increase the porosity of the soil and increase its ability to hold water. 5. Slow release fertilizers (which are generally resin -coated) can be used in addition to organic fertilizers. They are not mobile in the soil and are applied only once. Integrated Pest Management Rather than bringing out the sprayer whenever a pest infestation occurs in the garden, consider using Integrated Pest Management (also known as IPM). IPM emphasizes the evaluation of all factors including environmental effects before chemicals are applied. Pesticides should only be used as a last resort. Some of the tactics that can be used to decrease or eliminate the use of pesticides include: 1. Use of Natural Predators or Pathogens: Because chemical sprays generally kill many beneficial insects instead of just the target pest, it may be necessary to introduce natural predators back into the garden. Ladybugs, lacewings, predatory wasps and nematodes are all commercially available. Garter snakes and toads are also predators and should not be eliminated from the garden. There are some bacteria, viruses and insect parasites that are specific to pests and will not harm other insects or animals. A commonly used bacterium in the Puget Sound area is Bacillus thuringiensis (Bt), which is intended to control infestations of tent caterpillars. Products containing Bt are available at your nursery. 2. Habitat Changes: Many times a change of habitat can control pest infestations. Removal of old tires can cut down on the mosquito population by removing a convenient water -filled YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 51 location for them to breed in. Crop rotation, even in a small garden, can reduce the number of pest infestations. Removing last year's leaves from under rose bushes can cut down on the incidence of mildew and blackspot, as these fungi overwinter in dead leaves. 3. Timing: Crops that can overwinter (such as leeks or carrots) should be planted in the fall. This gives them time to become established before pests arrive in the spring. 4. Mechanical: Many eggs, larvae, cocoons and adult insects can be removed by hand. Be sure that the insect is properly identified prior to removing it so those beneficial insects are not destroyed in error. Drowning insects in plain water or spraying them with soapy water are alternatives to squashing them. 5. Resistant Plants: Plants that are native to this area are often more resistant to pests and tolerant of the climate than are introduced plants. Many plant cultivars have been developed which are resistant to such diseases as verticilium wilt and peach leaf curl. Grass seed mixes are also available for lawns that need much less watering, mowing and chemical use. 6. Growing Conditions: Plants, such as hostas, that require some shade are more susceptible to pests when they are growing in the sun. Improperly fertilized or watered plants are less vigorous in growth and tend to attract pests. Plants that prefer an acid soil, such as azaleas, will perform better and be less susceptible to pests when they are grown in soil with the proper pH. 7. Chemicals: Chemicals are a small part of the IPM plan and should be applied only as needed after reviewing all other alternatives. Pesticide Management When use of a chemical is the best or only option, follow these simple guidelines: 1. Know your target pest before spraying. Use the pesticide according to the manufacturer's instructions, and buy only the needed quantity. Many pesticides have a limited shelf life and may be useless or degrade into even more toxic compounds if stored for extended periods of time. 2. Do not apply more than the specified amount. Overuse can be dangerous to your health as well as the health of wildlife and the environment. If more than one chemical can be used to control the pest, choose the least toxic. The word "caution" on the label means that the chemical is less toxic than one that is labeled "warning". 3. Do not spray on windy days, in the morning of what will be a very hot day or when rain is likely. Herbicides can drift and injure valuable ornamental plants. Do not water heavily after application. Plants should be lightly watered before application to prevent burning of the foliage and to help evenly spread the chemical. 4. Never apply pesticides near streams, ponds or wetlands (exception: approved applications for aquatic weeds). Do not apply pesticides to bare eroded ground (exception: use of low toxicity herbicides such as Round -Up to allow growth of desired planting in small areas). Many pesticides bind to soil particles and can be easily carried into a stream or storm drain. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 52 5. Pesticides should be stored well away from living areas. Ideally, the storage area should have a cement floor and be insulated from temperature extremes. Always keep pesticides in their original containers with labels in tact. Labels often corrode and become illegible in this climate and may have to be taped onto the container. 6. Federal law now requires that all pesticides be labeled with the appropriate disposal method. Leftovers should never be dumped anywhere, including a landfill. Take unwanted pesticides to the County's hazardous waste collection days or Hazo House at the landfill. 7. Empty containers should be triple -rinsed and the rinse water used as spray. Once containers are triple -rinsed, they are not considered hazardous waste and may be disposed of in most landfills. However, call your local landfill before putting the container in the garbage. 8. If a pesticide is spilled onto pavement, it can be absorbed using kitty litter or sawdust. The contaminated absorbent should be bagged, labeled and taken to Hazo House. 9. If the pesticide is spilled onto dirt, dig up the dirt, place it in a plastic bag and take it to Hazo House, 10. Many pest control companies and licensed applicators have access to pesticides that are more toxic than those available to the consumer. Check with the company before they spray indoors or outdoors to find out what spray they will be using and what precautions, if any, are necessary after the operator leaves. References Puget Sound Water Quality Authority, Managing Nonpoint Pollution - An Action Plan for Puget Sound Watersheds, 88-31, June 1989. Washington State Dept. of Ecology, Water Quality Guide -Recommended Pollution Control Practices for Homeowners and Small Farm Operators 87-30, revised June 1991. Washington State Dept. of Ecology, Hazardous Waste Pesticides, 8941, August 1989, YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 53 IV. GLOSSARY BEST MANAGEMENT PRACTICE (BMP) -Structures, conservation practices or regulations that improve quality of runoff or reduce the impact of development on the quantity of runoff. BIOFILTER (SWALE) - A wider and flatter vegetated version of a ditch over which runoff flows at uniform depth and velocity. Biofilters perform best when vegetation has a thick mat of roots, leaves and stems at the soil interface (such as grass). BIOFILTRATION - The process through which pollutant concentrations in runoff are reduced by filtering runoff through vegetation. BUFFER - The zone that protects aquatic resources by providing protection of slope stability, attenuation of runoff and reduction of landslide hazards. An integral part of a stream or wetland ecosystem, it provides shading, input of organic debris and coarse sediments to streams. It also allows room for variation in stream or wetland boundaries, habitat for wildlife and protection from harmful intrusion. CATCH BASIN - An inlet for stormwater set into the ground, usually rectangular, made of concrete and capped with a grate that allows stormwater to enter. CHECK DAM - A dam (e.g., rock, earthen, log) used in channels to reduce water velocities, promote sediment deposition and/or enhance infiltration. COMPOST STORMWATER FILTER - A treatment facility that removes sediment and pollutants from stormwater by percolating water through a layer of specially prepared big leaf maple compost. CONSTRUCTED WETLAND - A wet pond with dead storage at varied depths and planted with wetland plants to enhance its treatment capabilities. CONTROL STRUCTURE (FLOW RESTRICTOR) - A manhole and/or pipe structure with a flow - regulating or metering device such as a weir or plates with small holes known as orifices. This structure controls the rate at which water leaves the pond. CONVEYANCE - A mechanism or device for transporting water including pipes, channels (natural and man-made), culverts, gutters, manholes, etc. CRITICAL AREA — Areas, such as wetlands, streams and steep slopes, defined by ordinance or resolution of the jurisdiction. Also known as "environmentally sensitive areas." CULVERT - A conveyance device (e.g., concrete box, pipe) that conveys water from a ditch, swale or stream under (usually across) a roadway or embankment. DEAD STORAGE - The volume of storage in a pond below the outlet that does not drain after a storm event. This storage area provides treatment of the stormwater by allowing sediments to settle out. DETENTION FACILITY - A facility (e.g., pond, vault, pipe) in which surface and stormwater is temporarily stored. DETENTION POND - A detention facility in the form of an open pond. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 54 DISPERSION TRENCH - An open -top trench filled with riprap or gravel that takes the discharge from a pond, spreads it out and spills (bubbles) the flow out along its entire length. Dispersion trenches are used to simulate "sheet flow" of stormwater from an area and are often used to protect sensitive adjacent areas, such as wetlands. DRAINAGE SYSTEM - The combination of Best Management Practices (BMPs), conveyances, treatment, retention, detention and outfall features or structures on a project. DROP STRUCTURE - A structure for dropping water to a lower elevation and/or dissipating energy. A drop may be vertical or inclined. DRY POND - A detention facility that drains completely after a storm. This type of pond has a pipe outlet at the bottom. EASEMENT - A right afforded a person to make limited use of another's real property. Typical easements are for pipes or access to ponds; they may be 15 to 20 feet wide. EMERGENCY OVERFLOW OR SPILLWAY - An area on the top edge of the pond that is slightly lower in elevation than areas around it. This area is normally lined with riprap. The emergency overflow is used only if the primary and secondary outlets of the pond fail, in the event of extreme storms or if the infiltration capability of the pond becomes significantly diminished. If the emergency overflow ever comes into play, it may indicate the pond needs to be upgraded. ENERGY DISSIPATER - A rock pad at an outlet designed to slow the water's velocity, spread out the water leaving the pipe or channel and reduce the potential for erosion. FREEBOARD - The vertical distance between the design high water mark and the elevation of the top of the pond. Most ponds have one to two feet of freeboard to prevent them from overflowing. INFILTRATION - The soaking of water through the soil surface into the ground (percolation). (Many ponds are designed to fully infiltrate stormwater and thus do not have a regularly used discharge pipe.) INFILTRATION FACILITY (or STRUCTURE) - A facility (pond or trench) that retains and percolates stormwater into the ground, having no discharge (to any surface water) under normal operating conditions. JUNCTION - Point where two or more drainage pipes or channels converge (e.g., a manhole). JURISDICTION - Olympia, Lacey, Tumwater or Thurston County (as applicable). LINED POND or CONVEYANCE - A facility, the bottom and sides of which have been made impervious (using, for example, a plastic liner or clay/silt soil layer) to the transmission of liquids. LIVE STORAGE - The volume of storage in a pond above the outlet that drains after a storm event. This storage area provides flood control and habitat protection for nearby streams. MANHOLE - A larger version of a catch basin, often round, with a solid lid. Manholes allow access to underground stormwater pipes for maintenance. NATURAL CHANNEL - Stream, creek, river, lake, wetland, estuary, gully, swale, ravine or any open conduit where water will concentrate and flow intermittently or continuously. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 55 OIL -WATER SEPARATOR - A structure or device used to remove oil and greasy solids from water. They operate by using gravity separation of liquids that have different densities. Many catch basins have a downturned elbow that provides some oikwater separation. OUTFALL - The point where water flows from a man-made conduit, channel or drain into a water body or other natural drainage feature. RETENTION FACILITY - An infiltration facility. RETENTION POND - A retention facility that is an open pond. REVETMENTS - Materials such as rock or keystones used to sustain an embankment, such as in a retaining wall. RIPRAP - Broken rock, cobbles or boulders placed on earth surfaces, such as on top of a berm for the emergency overflow, along steep slopes or at the outlet of a pipe, for protection against the action of water. Also used for entrances to construction sites. RUNOFF -Stormwater. SAND FILTER - A treatment facility that removes sediment and pollutants from stormwater by percolating water through a layer of sand. STORMWATER - That portion of precipitation that falls on property and that does not naturally percolate into the ground or evaporate but flows via overland flow, channels or pipes into a defined surface water channel or a constructed infiltration facility. Stormwater includes washdown water and other wastewater that enters the drainage system. SWALE - A shallow drainage conveyance with relatively gentle side slopes, generally with flow depths less than one foot. This term is used interchangeably with "BIOFILTER". TRASH RACK or BAR SCREEN - A device (usually a screen or bars) that fits over a pipe opening to prevent large debris such as rocks or branches from entering and partially blocking the pipe. NET POND - A stormwater treatment pond designed with a dead storage area to maintain a continuous or seasonal static water level below the pond outlet elevation. YELM CREEK APTS -PHASE 2 07.27.2020 PAGE 56 APPENDIX A -Site Development Drawings YELM CREEK APTS -PHASE 2 07.27.2020 PAGE A-1 YELIM CREEK APARTMENTS 1651 1 CREEK STREET SE, YELM, WA 98597 II ` X. pp I II \ 1 v4 ''�A,-4�do odd\�\ _ _ dd� 1I I� \ �\ ut \ ps IL / Y /6 PIPE, '.v 'V P. AEl e 0� PEEN( S door PIE, I If, 'Pp L \ \ ' \ \ v CU D \ PIPPIN I. > I/J,D. ! G` \ y / / \ ryfp Ed /I Pod, L vIdd- rv( I I I I II I Ili I I I i I II I PIPE PIE I I 1(unll! II rj I II II.) I I � I P.; I I II I I II III x I Inl� I I II II 6 1 _- 1 EX CARPoRT TYPI Ed IY�-`f FJi ,��,t /' / or Ed Ed, _ / i Ed Id 6511 CREEK RD. �/` r/w FF EfE= J I PIPE, 341.56 POE%� R$ - h. -. !' v I'd/ �PerI LIodd- Z — I ' IV r' � ....\V PIE. \ Pool > �1 p / Q ,\ \Ed doodood- rPOP dF L" h. IfPIPE, ILm 'd- 7657 ✓�' F 6cCgq '2 RD �L, -` i Et dod -dodd Ed III? F ; �' ��l f o, c ,_'..� � l I n I Iy I / "rr L— -- 'I T----- EXISTING 3" PVC STEP FORCEMAIN CI 1 YC SPL 71+00 ,I FOUND DISTURBED 3/8" REBAR AND CAP, 0.08' N AND 1.12' E OF SET REBAR AND CAP SOUTH PROPERTY UNE (SPI STATIONING LINE TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT. b II G I _.___ 1__�,_ x — #6 NEW 3 -STORY 12 UNITS I J- 4 PROPOSED CARPORT, TYP SHEET INDEX 1 COVERSHEEI' 2 HORIZONTAL CONTROL PLAN&SITE DETAILS 3 TEMPORARY EROSION CONTROL Be DEMOLITION PLAN 4 TEMPORARY EROSION CONTROL PLAN DETAILS 5 GRADING Be DRAINAGE PLAN 6 GRADING & DRAINAGE DETAILS 7 OV ERALLUTIDTYPI.AN 8 WATER PLAN 9 WATER DETAILS 10 SEWER PLAN 1 1 STEP SYSTEM NOTES & DETAILS 12 SEWER DETAILS 13 OVERALL LANDSCAPE PLAN 14 LANDSCAPE PLAN 15 LANDSCAPE DETAILS & SPECS 1 fi IRRIGATION PLAN 1% IRRIGATION DETAILS &SPECS or,, / \d( (OPEN SPACE) \. y \ NEW PARKING EXISTING BIORETENTION SWALE, PHASE 1 CONVEYANCE TO EXISTING S7oRM POND NEW SOLID WASTE DISPOSAL ENCLOSURE 8'x20' NEW FIRE HYDRANT & FDC'S NOTE: THIS DRAW4NG DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. SHALL VERIFY ALL U71LIN LOCATIONS PRIOR TO CONSTRUCTION BY CALLING THE UNDERGROUND LOCATE UNE AT 011 A MINIMUM OF 48 ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION. REVIEWED AND APPROVED BY HATTON GODAT PAINTER, DRNNACE SWALE E VICINITY MAP PROJECT PROPONENT: YELM CREEK LANE, LLC 724 COLUMBIA STREET NW SUITE 140 OLYMPIA, WA 98501 \ \CJr \ a- 'RIPARIAN BUFFER\' FROM O.H.W.M. �.. _.. \ I \ 60' SETBACK FROM HIGH GROUND WATER (H.G.WJ AREA REPLACEMENT 100 YR FLOOD PER FIRM MAPS 8 ALTA PIKE EXISTING ORMWATI POND MAPPED HIGH GROUND WATER (H.G.W J AREA r�� • 30 15 0 30 60 SCALE: In= 30' CITY OF YELM RIPARIAN 9UFFE8 MERIDIAN HORIZONTAL DATUM TRACTS BLA8160 TRACT B PER DOCUMENT 2463/8D3 THURSTON COUN TY BM #598 EN�cROµ� HM�NT CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT NET. 103RD AVE. 8 CREEK RD. NO. SS -8026, VOL25, NEW PARKING EXISTING BIORETENTION SWALE, PHASE 1 CONVEYANCE TO EXISTING S7oRM POND NEW SOLID WASTE DISPOSAL ENCLOSURE 8'x20' NEW FIRE HYDRANT & FDC'S NOTE: THIS DRAW4NG DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. SHALL VERIFY ALL U71LIN LOCATIONS PRIOR TO CONSTRUCTION BY CALLING THE UNDERGROUND LOCATE UNE AT 011 A MINIMUM OF 48 ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION. REVIEWED AND APPROVED BY HATTON GODAT PAINTER, DRNNACE SWALE E VICINITY MAP PROJECT PROPONENT: YELM CREEK LANE, LLC 724 COLUMBIA STREET NW SUITE 140 OLYMPIA, WA 98501 \ \CJr \ a- 'RIPARIAN BUFFER\' FROM O.H.W.M. �.. _.. \ I \ 60' SETBACK FROM HIGH GROUND WATER (H.G.WJ AREA REPLACEMENT 100 YR FLOOD PER FIRM MAPS 8 ALTA PIKE EXISTING ORMWATI POND MAPPED HIGH GROUND WATER (H.G.W J AREA r�� • 30 15 0 30 60 SCALE: In= 30' CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM TRACTS BLA8160 TRACT B PER DOCUMENT 2463/8D3 THURSTON COUN TY BM #598 CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT NET. 103RD AVE. 8 CREEK RD. NO. SS -8026, VOL25, ELEV.= 338.31 (NGVD 1929) PG 304 ABBREVIATED LEGAL DESCRIPTION SECTION 29 TOWNSHIP 17 RANGE 2E PLAT MCKENNA IRRIGATED TRACTS BLA8160 TRACT B PER DOCUMENT 2463/8D3 SITE DATA SITE ADDRESS ....................................... (PARCEL IS UNADDRESSED) ASSESSOR PARCEL NO ........................................... 64303400202 ZONING., ... ... ... .......0-2 SECTION... ... .. .. S29172E PERMITTING JURISDICTION .. CITY OF YELM FEMA PANEL .... .. 0354,0382 WATERSHED ... ... NISQUALLY RIVER PROPOSED USE ........................... 24 -UNIT EXPANSION OF EXISTING APARTMENTS ZONING DENSITY....................................................... _........ 8-16 DUTAC. PARCEL AREA ...... ,. 301 AC. (131,115 S.F.) CRITICAL AREAPORTION .. ... .1.86 AC. NET DEVELOPABLE AREA..................... .. 1.15 AC. PROPOSED DENSITY ........ .... 24 OU 13.01 AC 8 DUTAC. SETBACKS FRONT ... 15 (LOCAL), 25' (COLLECTOR) 35 (ARTERIAL) SIDE .. .. ... ..... 10 FT REAR _. .. ..... 25 FT FLANKING STREET .. 20 FT SURFACES PROPOSED IMPERVIOUS 20,196 S.F, CRITICAL AR EA .. .. B1,022AC, PROPOSED BUILDING ... ..................................... 9518 S.F PROPOSED LANDSCAPE.. .. .. 20,380 S.F. BLDG COV./DEV COV .. .. .... 72%1227% UTILITIES WATER CITY OF YELM SEWER .. CIN OF YELM STORM ... _........ .........ONSITE POWE .... .. .......PSE PHONE/CABLE .. ._. ...... COMCAST PARKING SUMMARY w PARKING RATIO REQUIRED ,. 2 PER DU UNITS PROPOSED, ...... _ _..... 24 OU STALLS PROVIDED ............................ .. ................ 48 NEW ORDINARY HIGH WA7ER LINE AS MAPPED BY SOUNDNEW CONSULTANT52019 -r. LEGEND EX WATER I. EX_ FIRE HYDRANT •`�� EX WATER METER �,� EX WATER VALVE Q EX WELL .......... �rELf. EX SEWER QS EX SANITARY SEWER MANHOLE ---Sl - — EX STORM DRAIN EX CATCH BASIN O EX POWER POLE IIIIIIIII EX POLE ANCHOR - , EX GUY POLE - EX TELEPHONE PEDESTAL ._-___ I __.__. EX GAS —OU— EX OVERHEAD UTILITY EX UTILITY EASEMENT --- EX FENCE y EX SIGN EX LUMINAIRE EX BUSH Ell EX CONIFEROUS TREE EX DECIDUOUS TREE P EX MAIL BOX • FOUND REBAR ® MONITOR WELL X MAGNAIL • r� SPOT ELEVATION - CENTERLINE SWALE — — — — RIGHT OF WAY -------- EXISTING EDGE OF PAVEMENT E NEWSEWERMAIN E E— NEW SEWER LATERAL Q 10 NEW SEWER MANHOLE • Pip NEW SEWER CLEANOUT PEEPE EX CONCRETE DEX GRAVEL EX LANDSCAPE OEX ASPHALT NEWCONCRETE OD DNEWASPHALT NEW LANDSCAPE IT 0 O m Z O t7 x o 0 W N r It m � 33 w w r � O O ❑ U ID/1 N z N R 3 g 0 APPROVED FOR CONSTRUCTION L BY: DATE' gGENCY NO. 2020.0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM SHEET: 1 OF C Eld9N19{100119-0351CDs INDEX 19-035 COV.d.V9 APPROVAL EXPIRES: JOB: 19-035 00 CITY OF YELM m ❑ Z Z VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COON TY BM #598 CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GP52 ATI NT. 103RD AVE. B CREEK RD. NO. SS -8028, VOL25, ELEV.= 338.31 (NGVD 1929) PG.304 TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. NMILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR SHALL OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE CALLING DRAWINGS AS A RESULT. NOTE; THIS DRAWING DOES NOT REPRESENTA RECORD DOCUMENT, UNLESS THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. VERIFY ALL UTILITY LOCATIONS PRIOR TO CONSTRUCTION BY THE UNDERGROUND LOCATE UNE AT 811 A MINIMUM OF 48 ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION. REVIEWED AND APPROVED BY HATTON GODAT PANTIER, 20 10 0 20 40 i w o SCALE: 1' = 20' N APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CITY OF YELM APPROVAL EX d rt AGENCY N0. 2020.0004 SHEET; 2 OF 17 EJdg NI9-000H 9-035/CDe INDEX: 19-03 PIRES:5 hcp, dJl9 JOB: 19-035 3 0 i w o N m m ❑ x > Y J N QQ 2 Q U K d rt AGENCY N0. 2020.0004 SHEET; 2 OF 17 EJdg NI9-000H 9-035/CDe INDEX: 19-03 PIRES:5 hcp, dJl9 JOB: 19-035 3 0 IN i_ Ir�fiUIN I r es IN NNNN v / /( I /IN rNININ ,'. / IN IN IN 11 IN/....� // / j lem /� /: / Sp. l IN Nee a IN ` ` �� 1 �` s�. v / le ON IN IN, <1cJ IN N / v�� Z/, NNNN- Net IN D"Ifil IN Koo er �j IN '8 SO w ellr < y / V Neil 7 IN NIX 1/ 1 Nee% Nei, r1 / INI/ IN, lie �'I N / � `-/ - \ \ I, - M-FM-FM-FM-Fm- ell FM FM FM Fm- i - IN II I - I_ _. -1 L._ 1 _ - ._ __- IN INSTALL STABILIZED CONSTRUCTION ENTRANCE BMP C105, SEE SHEET 4 INLET SEDIMENT PROTECTION BMP C220 TOPOGRAPHIC NOTE: THE E%ISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS, WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE,HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR STORMWATER THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR SHALL OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE CALLING DRAWINGS ASA RESULT. EXISTING ASPHALT DRAINAGE SWALE TO BE REPLACED WITN STRUCTURE CLEARING LIMITS FLOW PATH TO EXISTING 9TORMWATER SWALE TO BE REESTABLISHED ONSITE AS PERMEABLE PAVEMENT OVERFLOW NOTE: THIS DRAVv1NG DOES NOT REPRESENTA RECORD DOCUMENT, UNLESS THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. VERIFY ALL UTILITY LOCATIONS PRIOR TO CONSTRUCTION BY THE UNDERGROUND LOCATE UNE AT 511AMINIMUM OF 48 ANY ALTERATIONS TO 7HE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION, REVIEWED AND APPROVED BY HATTON GODAT PANTIER. EXISTING ASPHALT DRAINAGE SWALE STRIP TO BE REMOVED DR4INAGE SWALE W EXISTING GRAVEL ROAD TO BE REMOVED CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COUN TY BM #595 4D CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. & CREEK RD. NO. SS -8026, VOL.251 ELEV = 338,31 PG.304 (NGVD 1929( = 20' LEGEND ■��■ •�� CLEARING LIMITS — FILTER FABRIC FENCING fy MONITORING WELL LOCATIONS INLET SEDIMENT PROTECTION \SO RiA aRo q\ry )y Fe\ i ROCK CHECK DAM (BMP C207) TOP EL 33g3 TO MATCH WEST END OF SWALE SEE DETAIL SHEET 4 20 10 0 20 4D x w ❑ SCALE: 1" = 20' N FILTER FABRIC FENCING AT LIMITS OF CLEARING 8 GRADING BMP C23J FILTER FABRIC FENCING AND CLEARING LIMITS FENCING MAY m BE COMBINED BY USING ORANGE FILTER FABRIC FENCING WHEN APPROVED BY JURISDICTION AND INSPECTOR N O x x w ❑ N m � mo w m x > N 33Q w Ja W K I r Q U 0 0 z APPROVED FOR CONSTRUCTION ` BY: DATE: AGENCY NO. 20200004 DEVELOPMENT REVIEW ENGINEER, CIN of YELM SHEET: 3 OF EIdgN-0W 11 199-035/CC os INDEX: 19-035 ec.dw9 APPROVAL EXPIRES: JOB: 19-035 ROCK CHECK DAM 2018 STORMWATER MANAGEMENT MANUAL FOR WESTERN Vew Looking Upstream =woo ,f°i9I(�, �,p AI " dry II rn - �Jfi Y .+IM Hsdmie.d.wnW. (T..\ A Sedon A -A w.HPmJ y � y :1 m m0 W Spacing Between Check Dams 2 s w+I�.l - - s- W (7 3 U Ili Rock Check Dam d� ......m.>al O 1FARTUENT OF y o ECOLOGY „a,,,,yw..,.....•w.,y,,.e,e�,u..,,e..�,.. PARTMEN7 OF d dsV.� ECOLOGY WASHINGTON VOLUME II, CHAPTER 3. FIGURE II -3,16 BMP C201 STRAW WATTLES DETAIL 2018 STORMWATER MANAGEMENT MANUAL FOR WESTERN WASHINGTON VOLUME 11, =woo rn Y w.HPmJ y � y m m0 W m 2 s w+I�.l W (7 3 U Ili d� O WalUes y o .....I>m..m U PARTMEN7 OF ECOLOGY m"m." emr..mav:v,. CHAPTERS FIGURE IW.24 BMP 0235 1. CONSTRUCTION ON THIS SITE SHALL BE CONDUCTED SUBSTANTIALLY IN ACCOROANCE WITH THE APPROVED PLANS. DEVIATI ONS FROM THESE PLANS SHALL BE SUBMITTED TO THE PROJECT ENGINEER AND REVIEWING AGENCY. DEVIATIONS MUST BE MPROVED PRIOR TO ANY SITE DISTURBING ACTIVITY NOT CONTAINED WITHIN THE APPROVED PLANS, 2 FOR DEVELOPMENT OF THIS SITE, THE FOLLOWING GENERAL SEQUENCE SHALL BE OBSERVED; 0. INSTALL STABILQED CONSTRUCTION ENTRANCE TO PROVIDE SITE ACCESS AT INDICATED CONSTRUCTION ENTRANCE LOCATION. INSTALL VEGETATION PROTECTION FENCING AND TREE PROTECTION FENCING AS SHOWN IN THESE PLANS. B, CALL FOR INSPECTION BY THE REVIEWNG AGENCY AND PROJECT ENGINEER. C. BEGIN TREE CLEARING AND GRUBBING OF AREAS WHICH ARE TO BE GRADED , O. BEGIN GRADING OF AREA TO SUBGRAOE AS SPECIFIED. E. INSTALLATION OF STORM DRAINAGE FACIUTIE6 (I.E., PIPING, CATCH BASINS, AND OTHER UTILITIES.) F, STRUCTURE CONSTRUCTION. G. PERMEABLE PAVEMENT SURFACE AND COMPACT TO 90%-92% COMPACTION. INSTALL POROUS PAVEMENT S ECTION PER SHEET 5. K PERMANENT EROSION CONTROL MEASURES O.E., HYDROSEEDING, GRASSING, PLANTINGS. ETC) ].ONCE THE SITE HAS BEEN DISTURBED, CONTINUE OPERATIONS GEN11I TOWARD COMPLETION AND STASIUZATION OF THE SITE. A. MOMTOR ALL EROSION CONTROL FACIUTIES, REPAIR, MODIFY, AND ENHANCE AS DIRECTED OR AS REQUIRED. CONCRETE HANDLING NOTES: BMP 0151 1. ANYTIME CONCRETE IS USED THESE MANAGEMENT PRACTICES SHALL BE UTILIZED, 2 CONCRETE PROJECTS INCLUDE BUT ARE NOT LIMITED TO CURBS, SIDEWALKS, ROADS, DRIVEWAYS, BRIDGES, FOUNDATIONS, FLOORS, STREET LIGHT BASES AND UTILITY BLOCKING 3. CONCRETE EQUIPMENT SHALL BE WASHED OUT ONLY IN FORMED"WASH OUT"AREAS. 4, UN USED CONCRETE SHALL BE RETURNED TO THE BATCH PLANT FOR RECYCLING, 5. CONCRETEWASHOUT AREAS SHALL BE CHECKED AND REPAIRED DAILY. 1. SAW CUTTING ANO SURFACING OPERATIONS GENERATE SLURRY AND PROCESS WATER THAT CONTAIN FINE PARTICULATES AND HIGH PH. 2 ANYTIME SAWCUTTING AND SURFACING OPERATIONS TAKE PLACE, THESE BEST MANAGE PRACTICES SHALL BE UT UZFO 3. SAW CUTTING AND SURFACING OPERATIONS INCLUDING BUT NOT LIMITED TO CONCRETE SAWING, CORING, GRINDING, ROUGHENING OR HYDRODEMOLITION. 4. SLURRY AND CUTTINGS SHALL BEVACUUMED DURING OPERATIONS. 5. SLURRY AND CUTTINGS SHALL NOT REMAIN EXPOSED TO THE ELEMENTS OVERNIGHT. 6. SLURRY AND CUTTINGS SHALL NOT BE ALLOWED TO DRAIN TO NATURAL OR CONSTRUCTED DRAINAGE CONVEYANCE PATHS. 7. COLLETED SLURRY AND CUTTINGS SHALL BE DISPOSED OF IN A MANNER THAT DOES NOT VIOLATE GROUNDWATER OR SURFACE WATER QUALITY STANDARDS. e. WASTE MATERIAL AND DEMOLITION DEBRIS MUST BE HANDLED IN A MANNER THAT DOES NOT CAU SE CONTAMINATION OF WATER. IF THE AR EA IS SWEPT WITH WITH MECHANICAL SWEEPER, THE MATERIAL MUST BE HAULED OUT OF THE AREA TO AN APPROVED DISPOSAL SITE. 1. ALL DEWATERING FROM OPEN CUT EXCAVATION, TUNNEUNG, FOUNDATION WORK TRENCHING OR UNDERGROUND VAULTS SHALL BE DISCHARGED INTO A CONTROLLED CONVEYANCE SYSTEM PRIOR TO DISCHARGE TO A SEDIMENT TRAP OR POND. 2 CHAN NELS USED FOR THIS PURPOSEWILL BE STABIUZEDWITH EROSION BLANKETS, CHECK DAMS, SEEDING, SODDING, MULCHING, OUTLET PROTECTION AND/OR ANY OTHER MEANS DEEMED NECESSARY BY THE PROJECT CESCL TO ENSURE EROSION AND BE CONTROL STANDARDS ARE MET. 3. HIGHLY TURBID DEWATERING WATER FROM SOILS KNOWN OR CONTAMINATED,OR FROM USE OF SUSPECTED TO BE CONSTRUCTIONEQUIPMENT, WILL THE REQUIRE ONAL MONITORING AND TREATMENT FOR THE SPECIFIC POLLUTANT(S) BASED dN THE CONTAMINATION, 4. WHEN ITHA PRING WATER OBEINGCCERN, HE EDT TERINGWATER BODY WITHAPOLLUTANTS) I CONCERN, THE DEWATERING WATER MUST BE MONITORED IN ACCORDANCE WITH CHAPTER fi OF THE CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) FOR THE PROJECT. 5. SUCH MONITORING ISTHE RESPONSIBILITY OF THE CONTRACTOR. 6. THE DEWATERING OF SOILS KNOWN TO BE FREE OF CONTAMINATION WILL, ATA MINIMUM, TRIGGER BMPS TO TRAP BE AND REDUCE TURBIDITY, 7. AT MINIMUM, GEOTEXTILE FABRIC SOCKSIBAGS/CELLS WALL BE USED TO FILTER THIS MATERIAL PRIOR TO ITS RELEASE TO A RELATIVELY LEVEL VEGETATED AREA 8. WHERE NOT COST PROHIBITIVE, DEWATERING WATER, AFTER BEING FILTERED BY A GEOTEXTILE FABRIC SOCK/BAG/OR CELL, SHOULD BE DIRECTED TO ONE OF THE PONDS FOR INFILTRATION OR METERED RELEASE 'S O BE USED FOR SEDIMENT TRAPPING AND 9, OTHERBMP T TURBIDITY CRETE HANDLING 15 . CONCRETE HANDLING BMP C751 . TEMPORARY SEDIMENT POND BMP C241 (POND 'B) .INFILTRATION (POND 'A') • USE OF A SEDIMENT BAG WITH OUTFALL TO A VEGETATED SWALE FOR SMALL VOLUMES OF LOCALIZED DEWATERING . CONSTRUCTION STORMWATER FILTRATION BMP C251 THE PROJECT CESCL SHOULD DETERMINE WHICH BMPS ARE MOST APPROPRIATE FOR SPECIFIC DEWATERING USES, CONSTRUCTION STORMWATER FILTRATION SHOULD ONLY BE USED AS LAST RESORT WHEN ALL OTHER OPTIONS HAVE BEEN EXHAUSTED AND THE SITE CANNOT MEET TURBIDITY/POLLUTION MONITORING REQUIREMENTS OTHERWISE. EROSION CONTROL SEEDING NOTES: BMP C120 1. SEED MIXTURE% PERENNIAL RYE, 5INGSORP OR BLUEGRASS,50%PERENNIALRYE,IT REDTOPLO COLO NIALBENTGRTE AND 5%WHITE DUTCH CLOVER APPLIED ATTIRE RATE OF 120 POUNDS PER ACRE. 2 SEED BEDS PLANTED BETWEEN MAY 1 AND OCTOBER 31 WILL REQUIRE IRRIGATION AND OTHER MAINTENANCE AS NECESSARY TO FOSTER AND PROTECT THE ROOT STRUCTURE. 3. FOR SEED BEDS PLANTED BETWEEN OCTOBER 31 AND APRIL 30, ARMORING OF THE SEED BED WILL BE NECESSARY (EG., GEOTEXnLES,JUTE MAT, CLEAR PLASTIC COVERING). 4. BEFORE SEEDING, INSTALL NEEDED SURFACE RUNOFF CONTROL MEASURES SUCH AS GRADIENT TERRACES, INTERCEPTOR DIKES, SWALES, LEVEL SPREADERS AND SEDIMENT BASINS. S. THE SEEDBED SHALL BE FIRM WITH A FAIRLY FINE SURFACE, FOLLOWING SURFACE ROUGHENING. PERFORM ALL CULTURAL OPERATIONS ACROSS OR AT RIGHT ANGLES TO THE SLOPE. 6. FERTILIZERS ARE TO BE USED ACCORDI NO TO SUPP U ERS RECOMMENDATIONS. AMOUNTS USED SHOULD BE MINIMIZED, ESPECIALLY ADJACENT TO WATER BODIES AND WETLANDS 7. MULCH MATERIALS USED SHALL BE HAY OR STRAW, AND SHALL BE APPLIED AT THE RATE OF 2-3 TONSIACRE OR OTHER WOOD FIBER CELLULOX MATERIAL TO BEAPPLIED AT THE RATE OF APPROXIMATELY 10D TONS I ACRE. 2 MULCHES SHALL BE APPLIED IN ALL AREAS WITH EXPOSED SOILS. 3. MULCHING SHALL BE USED IMMEDIATELY AFTER SEEDING OR IN AREAS WHICH CANNOT BE SEEDED BECAUSE OF THE ON. 4, ALL AREAS NEEDING MULCH SHALL BE COVERED BY NOVEMBER I. 5. MULCH MUST BE MAINTAINED UNTIL SITE RAS ESTABUSHED SO%GRASS COVERAGE. 1. ALL FlLLAREA SLOPES SMALL BE ROUGHENED USING ONE OF THE METHODS FROM BMP C730 AS FILL IS BEING PLACED. 2. ALL DISTURBED AREA53HALL BE SEEDED AND MULCHED PEq THE NOTES AND DETAILS IN THIS PIAN BET AND PER BMPS cuo ANOcut. 3. IN NO CASE SHALL DISTURBED SOILS REMAIN UNSTABILIZED AND UNWORKED FOR MORE TRAM T DAYS DURING THE DRY SEASON (MAY 1 TO SEPTEMBER 30) OR MORE THAN 2 DAYS DURING THE WET SEASON (OCTOBER 7 TO APRIL 30) AS MANUFACTURED BY ARD (#3001) BY RETRIEVALSTRAP FOSS ENVIRONMENTAL OR EQUIVALENT AB �4• ADAPTER SKIRT � OVERFLEW UNDERFLOW (TO BYPASS GEOTEXTILE FABRIC DISCHARGE PEAK STROM VOLUMES) ) V OIL SORBENT FILTER PACK I -SEDIMENT ACCUMULATION INLET SEDIMENT PROTECTION (BMP C220) N.T.S. INLET SEDIMENT PROTECTION NOTES: (BMP C220) 1. INSTALL INSERT PER THE MANUFACTURER'S SPECIFICATIONS 2. MAINTAIN AND REPLACE INSERTS AS RECOMMENDED BY THE MANUFACTURER, AS REQUIRED BY THE INSPECTOR OR PROJECT ENGINEER, AND AS OTHERWISE NECESSARY. JOINTS IN FILTER FABRIC SHALL BE SPILICED AT POSTS. USE STAPLES OR WIRE RING TO ATTACH FABRIC TO POSTS, 2'k2'X74GA WIRE FABRIC OR EQUIVALENT IF STANDARD STRENGTH FABRIC USED FILTER FABRIC 2"x2'x14GA IMRE FABRIC OR EQUIVALENT IF STANDARD STRENGTH FABRIC USED PROVIDE 3/4"-11/2" WASHED GRAVEL BACKFILL IN TRENCH BURY BOTTOM OF FILTER MATERIAL IN 4'k4"TRENCH 2'k4" WOOD POSTS, STANDARD OR BETTER OR EQUAL ALTERNATIVE'. STEEL FENCE POSTS 4"MIN.J 2'k4"WOOD POSTS, STANDARD OR BETTER OR EQUAL ALTER NATIVE: STEEL FENCE POSTS FILTER FABRIC FENCE DETAIL (BMP C233) N.T.S. 1. FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT 70 THE LENGTH OF THE BARRIER TO AVOID USE OF JOINTS. WHEN JOINTS ARE NECESSARY, FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY ATASUPPORT POST, WITH AMINIMUM 6 -INCH OVERLAP, AND SECURELY FASTENED AT BOTH ENDS TO POST. 2. POSTS SHALL BE SPACED A MAXIMUM OF 6 FEET APART AND DRIVEN SECURELY INTO THE GROUND (MINIMUM OF 12 INCHES). 3. ATRENCH SHALL BE EXCAVATED APPROXIMATELY 4 INCHES WIDE AND 4 INCHES DEEP ALONG THE LINE OF POSTS AND UPSLOPE FROM THE BARRIER. 4. WHEN STANDARD STRENGTH FILTER FABRIC IS USED, A WIRE MESH SUPPORT FENCE SHALL BE FASTENED SECURELY TO THE UPSLOPE SIDE OF THE POSTS USING HEAVY-DUTY WIRE STAPLES AT LEAST 1 INCH LONG, TIE WIRES OR HOG RINGS, THE WIRE SHALL EXTEND INTO THE TRENCH A MINIMUM OF 4 INCHES AND SHALL NOT EXTEND MORE THAN 24 INCHES ABOVE THE ORIGINAL GROUND SURFACE. 5. THE STANDARD STRENGTH FILTER FABRIC SHALL BE STAPLED OR WIRED TO THE FENCE, AND 20 INCHES OF THE FABRIC SHALL BE EXTENDED INTO THE TRENCH. THE FABRIC SHALL NOT EXTEND MORE THAN 24 INCHES ABOVE THE ORIGINAL GROUND SURFACE. FILTER FABRIC SHALL NOT BE STAPLED TO EXISTING TREES. e. WHEN EXTRA -STRENGTH FILTER FABRIC AND CLOSER POST SPACING IS USED, THE WIRE MESH SUPPORT FENCE MAY BE ELIMINATED. IN SUCH A CASE, THE FILTER FABRIC IS STAPLED OR WIRED DIRECTLY TO THE POSTS WITH ALL OTHER PROVISIONS OF ABOVE NOTES APPLYING. 7. FILTER FABRIC FENCES SHALL NOT BE REMOVED BEFORE THE UPSLOPE AREA HAS BEEN PERMANENTLY STABILIZED. B, FILTER FABRIC FENCES SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND AT LEAST DAILY DURING PROLONGED RAINFALL ANY REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY, 7. APPROVAL OF THIS EROS IO NISEDIMENTATIONCDNTROL (ESC) PLAN DOES NOT CONSTITUTE AN APPROVAL OF PER-MANENT ROAD OR DRAINAGE DESIGN (E,G. SIZE AND LOCATION OF ROADS, PIPES, RESTRICTORS, CHANNELS, RETEN-TION FACILITIES, UTILITIES). 2. THE IMPLEMENTATION OF THIS ESC PLAN AND THE CONSTRUCTION, MAINTENANCE, REPLACEMENT, AND UPGRAD-ING OF THESE ESC BMPS IS THE RESPONSIBILITY OF THE APPUCANT UNTIL ALL CONSTRUCTION IS COMPLETED AND APPROVED AND VEGETATION/LANDSCAPING IS ESTABLISHED. 3.CLEARLV FLAG THE BOUNDARIES OF THE CLEARING LIMITS SHOWN ON THIS PIAN IN THE FIELD PRIOR TO CONSTRUCTION. DURING THE CONSTRUCTION C BEYOND LAGGED CLEARING LIMITS SHALL BE PERIOD NO TURBANCE BEV N F PERMITTED. THE FLAGGING SHALL BE MAINTAINED BY THE APPLICANT FOR THE DURATION OF CONSTRUCTION. 4. CONSTRUCT THE ESC BMPS SHOWN ON THIS PLAN IN CONJUNCTION WITH ALL CLEARING AND GRADING ACTMTIES, AND IN SUCH A MANNER AS TO ENSURE THAT SEDIMENT AND SEDIMENT LADEN WATER 00 NOT ENTER THE DRAIN -AGE SYSTEM, ROADWAYS, OR VIOLATE APPLICABLE WATER STANDARDS, 5. THE ESC BMPS SHOWN ON THIS PLAN ARE THE MINIMUM REQUIREMENTS FOR ANTICIPATED SITE CONDITIONS. DURING THE CONSTRUCTION PERIOD, UPGRADE THESE ESC BMPS AS NEEDED FOR UNEXPECTED STORM EVENTS AND TO ENSURE THAT SEDIMENT AND SEDIMENT -LADEN WATER DO NOT LEAVE THE SITE. e. THE APPLICANT SHALL INSPECT THE ESC BMPS DAILY AND MAINTAIN THEM AS NECESSARY TO ENSURE THEIR CONTINUED FUNCTIONING. 7. INSPECT PNDMAINTAIT THE ESC BMPS ON INACTIVE SITES JMINIMUM OF ONCE A MONTH OR WITHIN THE 48 HOURS FOLLOWING A MAJOR STORM EVENT (I.E. A 24-HOUR STORM EVENT WITH A 10.YR OR GREATER RECURRFIJCE INTERVAL), e, AT NO TIME SHALL THE SEDIMENT EXCEED 60-PERGENT OF THE SUMP DEPTH OR HAVE LE55 THAN &INCHES OF CLEARANCE FROM THE SEDIMENT IPE. L CATCH BASINS AND SU TOT LINES SHALL BE LOWESTPIPE.AL RFACE CON-VEYANCE LINES SHALL H CLEANED PRIOR WPAVING.THECLEANING OPERATION SHALL NOT (LUSH SEDIMENT LADEN WATER INTO THE DOWHSTRFAM SYSTEM, 9. INSTALL STABILIZED CONSTRUCTION ENTRANCES ATTHE BEGINNING OF CONSTRUCTION AND MAINTAINED FOR THE DURATION OF THE PROJECT, ADDITIONAL MEASURES MAY BE REQUIRED TO ENSURE THAT ALL PAVED AREAS ARE KEPT CLEAN FOR THE DURATION OF THE PROJECT, IN GENERAL, ALL BMP'S SHALL BE CHECKED WEEKLY AND AFTER A SIGNIFICANT RAINFALL (MORE THAN LBEC ECKELYo.SINCHES IN 24 HOURS). THE FOLLOW NG ITEMS SHALL BE CHECKED IN PARTICULAR' 1. SEDIMENT BASINS SHALL BE CLEANED OUT WHEN THE LEVEL OF SEDIMENT REACHES 1 -12 -FEET FROM THETOP OF THE RISER PIPE Z GRAVEL AROUND THE RISER PIPE SHALL BE CHECKED REGULARLY FOR SEDIMENT BUILOUP WHICH WOULD RESTRICT DRAINAGE. IF THE GRAVEL BECOMES CLOGGED WITH SILT, IT SHALL BE REPLACED. 3. DIVERSION DIKES AND SWALES SHALL BE CHECKED FOR BLOCKAGE AND DAMAGE ON A REGULAR BASIS. WATER SHALL MOVE FREELY BEHIND DIKES AND IN SWALES AT ALL TIMES. 4. PIPE SLOPE DRAINS SHALL BE CHECKED FOR STASIUTY. NO UNDERMINING OF THE PIPE SHALL BE ALLOWED. 5. FILTER FENCE SHALL BE CHECKED REGULARLY FOR UNDERMINING AND SEDIMENT BUILDUP. SEDIMENT SHALL BE REMOVED ONCE IT REACHES DEPTH OF OCT 6. EROSION CONTROL BLANKETS SHALL BE CHECKED FOR STABIUTY, FINE BLAIJKETS SHALL BE HELD IN PLACE AND HAVE GOOD CONTACT WITH THE FILL SLOPE AT ALL TIMES. 7. ALLSEEOED AND SODDED AREAS, ESPECIALLY FILL SLOPES, SHALL BE CHECKED REGULARLY TO MAKE SURE VEGETATIVE COVERAGE IS COMPLETE. AREAS SHALL BE RESEEDED AND FERTILIZED AS NEEDED. B. TRACKING OF MUD OFF-SITE WILL NOT BE ALLOWED. IF EXCESSIVE MUD IS TRACKED OFF SITE, IT SHALL BE CLEANED WITH A STREET SWEEPER. FURTHER TRACKING SHALL THEN BE PREVENTED BY WASHING TRUCK TIRES OR SWEEPING CONTINUOUSLY. / OPO G �-i'xSAxa �.4 12" MIN. DEPTH GEOTEXTILE FABRIC PER BMP C105 15' MIN. PROVIDE FULL WIDTH OF 4"TO 8'QUARRY SPALLS INGRESS /EGRESS AREA STABILIZED CONSTRUCTION ENTRANCE (BMP C 105) N.T.S. 1. MATERIAL SHALL BE 4 INCH TO a INCH QUARRY SPALLS AND MAY TOP -DRESSED WITH 1 INCH TO 31NCH ROCK. (STATE STANDARD SPECIFICATIONS.( 2. THE ROCK PAD SHALL BE AT LEAST 12 INCHES THICK AND 100 FEET LONG. WIDTH SHALL BE THE FULL WIDTH OF THE VEHICLE INGRESS AND EGRESS AREA SMALLER PADS MAY BE APPROVED FOR SINGLE-FAMILY RESIDENTIAL AND SMALL COMMERCIAL SITES. 3, ADDITIONAL ROCK SHALL BE ADDED PERIODICALLY TO MAINTAIN PROPER FUNCTION OF THE PAD. 4. IF THE PAD DOES NOT ADEQUATELY REMOVE THE MUD FROM THE VEHICLE WHEELS, THE WHEELS SHALL BE HOSED OFF BEFORE THE VEHICLE ENTERS A PAVED STREET. THE WASHING SHALL BE DONE ON AN AREA COVERED WITH CRUSHED ROCK AND WASH WATER SHALL DRAIN TO A SEDIMENT RETENTION FACILITY OR THROUGH A SILT FENCE. APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CIN OF YELM APPROVAL EXPIRES: AGENCY N0. 21720.0004 SHEET; 4 OF 17 EddgN19-000113035/CDs INDEX: 19-035 ec.dw9 JOB: iB-035 F =woo rn Y m m0 W m 2 7 W (7 3 U Ili O O y o U AGENCY N0. 21720.0004 SHEET; 4 OF 17 EddgN19-000113035/CDs INDEX: 19-035 ec.dw9 JOB: iB-035 F POROUS ASPHALT SEE SECTION 8 NOTES THIS SHEET 12+95.35, 101.17' LT (SPL) "T CONNECT TO PERF PIPE 1 FL 33B.0 I 28 LF 6" PVC ROOF DRAIN ® 0.005 FTIFT 12+72.46, 136.53' LT (SPL) /\AN INSTALL AAI 1•CLEANOUT � FL 338,36idddd 1 43 LF 6" PVC OF DRAIN \ : \ ®0.Id 005 FTIFT 11 1 AN ,I \ NAN I AN A or A Add 101 LF 6" PVC C` ROOF DRAIN A® 0.005 FTIFT ( / AN A 11+71.380 135.93' LT (SPL) / INSTALL 1 -CLEANOUT FL 338.87 \ \\ ` � \I Id / \� ''. ANA A /;/1{ A J / 1,, \i; I AdAd 0-A Ad AAA � / 7 34j.0 A,vI L ::.i.. -. Add IT NI ad dr ,. AN I'd/IN ANN BLDG 6 �yFFL342 11+67.41, 92.09' LT (SPL) >Ad r" I/Ad �' ^ ��\�, \\` /' Add 1-CLEANOUTAd �� / ,` FL 338,67 i� .,.. AN \ Add :NIANN'dA INA J. tt A AAA JI �� /II� J41n,744 Ad Al I,l l 105 LF 6" PVC {\ • I Ad__ _.._ Ad_ ROOF DRAIN AAAAAAA O 0.005 FTIFT 12+24.351 63.00' LT (SPL) Ad �� ! 040.7 —d INSTALL �� 1 - OBSERVATION PORT I— II FL 338.0 / -- - -_._ I ____J --1, - —I-- 1.._—L -- I AA — — - — SOUTHPROPERTYLINE(SPL)= .....__AAAI. A, .__,AAA .., ..._. STATIONING LINE / SPL EKISTING FLOW lzwo PATH � TO BE DISTURBED 12+18.58, 45.54' LT (SPL) INSTALL 1 • TYPE 1 CB RIM 340.5 FL 339.0 38 LF 6" PVC PIPE 12+30.240 9.64' LT (SPL) RIPRAP OUTFALL FL 340.1 EXISTING UTILITY NOTE: EXISTING UTILITY LOCATIONS SHOWN ARE FROM VARIOUS RECORDS. CONTRACTOR TO FIELD VERIFY ALL UTILITIES PRIOR TO CONSTRUCTION. "CALL BEFORE YOU DIG" 811, 48 HOURS IN ADVANCE. THIS DRAWING DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS CERTIFIED BY HATTON GODATPANTIER. ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE REVIEWED AND APPROVED BY HATTON GODAT PANTIER. 72+95.35, 158.42' LT (SPL) INSTALL 1. OBSERVATION PORT FL 338.0 96 LF 6" PVC PERF PIPE FL 338.0 13+19.35, 159.46'LT (SPL) INSTALL 1. OBSERVATION PORT FL 338.0 13+19.36, 144.46' LT (SPL) CONNECT TO PERF PIPE FL J3B.0 106 LF 6" PVC ROOF DRAIN FTIFT \ A ANAN' Ad As Ad 40.66ro , \ Ad! j de. i \ r / � i/// i Z i jiii r nd A r TA i BLDG 7 FFL 341 12+69.83. 90.99' LT (SPL) J 71 LF B" PVC INSTALL PERF PIPE 1 -CLEANOUT FL 338.0 FL J3B.14 12+95.35, 63.00' LT (SPL) INSTALL 1.OBSERVATION PORT FL 338.0 TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY NOTE: OTHERS. WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP THE CONTRACTOR SHALL BE FULLY CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR I THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR SHALL OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE CALLING DRAWINGS AS A RESULT. Ad 13+50.20, 1fi1.30'LT (SPL) INSTALL OUT 44 FL 338.70 44 L F 6" PVC ROOF DRAIN 07 0.005 FTIFT 13+93.2B, 160938' LT (SPL) INSTALL 1 -CLEANOUT FL 338.92 DOWNSPOUT, TYP NON Ad I AAA A ANN Ad A AAA A Add I ANA I AN Ad AN / ;j: DF. E'S ALE - ./;;'.. A Ad Ad . r _._...._.p, ,. /:.. 99 LF 6" PVC ROOF DRAIN ®0.005 FTIFT 13+48.44, 58.33' LT (SPL) 9B LF 6" 13+92.19, 57.28' LT (SPL) PVC INSTALL PERF PIPE 1 1,CLEANOUT FL 338.0 FL 338.18 61.23' LT (SPL) � 13419.35, INSTALL 1 •OBSERVATION PORT FL 338.0 3' CURB CUT OPENING SEE DETAIL THIS SHEET INSTALL 1•CLEANOUT FL 333.49 THIS DRAWING DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. VERIFY ALL UTILITY LOCATIONS PRIOR TO CONSTRUCTION BY THE UNDERGROUND LOCATE LINE AT 611AMINIMUM OF 48 ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION. REVIEWED AND APPROVED BY HATTON GODAT PANTIER. CITY OF YELM Add VERTICAL DATUM MERIDIAN HORIZONTAL DATUM 95-100 THURSTON COUN TY BM #596 70-100 CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GP52AT INT, 103RD AVE. S CREEK RD. NO. SS -8028, VOL. 25, ELEV = 338,31 PG 304 (NGVD 1929( <4 20 10 0 20 4D SCALE: 1" = 20' LEGEND (-- EXISTING DRAINAGE _1 POROUS PAVEMENT 4" -POROUS ASPHALT 18-25°6 VOIDS "T- 2" -CHOKER COARSE l \ ��:,�:; 12" -BALLAST QA NAA I a5 6" -SAND, SEE SAND MEDIUM SPECIFICATION THIS SHEET POROUS ASPHALT PAVING N.T.S. SIEVEC Y. PASSING 4 95-100 S 70-100 6 40-90 30 25-75 50 2-25 100 <4 ze0 <2 CURB CUT DETAIL N.T.s, w c6 x x w O N )AA � w m p x > O O U �. N if APPROVED FOR CONSTRUCTION ` BY: DATE: gGENCV No. 2020.0004 DEVELOPMENT REVIEW ENGINEER, CIN OF YELM SHEET: 5 OF 17 EldgN19-000/140i5/C Ds INDEX 19-035 grd3drn.dwg APPROVAL EXPIRES: JOB: 19-035 SUBGRADE PREPARATION - 1. Careful attention to subgrade preparatlon during c nstruction Is required to balance the needs for structural suppoitwhile maintaining Infiltration ca acity For all permeable ppavements, relative unPronnuty of subgrade conditions Is necessary to pprevent differential setting or other stress across the system. 2 Fin algracing should be complete by machinery operating an a preliminary subgrade that Is at least 12 inches higher than finalg ade, Final excavation shall proceed as machinery Is pullin hack and traveling on preliminary grade as fina� grade Is excavated. 3. of roll subgrade to a firm and unyielding condition. Do not over compact. 4. To prevent compaction when installing the aggregate base the following steps shall be followed: 1� the aggregate base Is dumpp d onto the subgrade from the edge of the Installation and aggregate Is then pushed out onto the subgrade; 2) trucks then dump subsequent loads from on top of the aggregate base as the Installation progresses, 5. Avold subgrade preparation during well periods, 6. If machinery must access the final grade, limit the access to a specie travel way that can be filled before application of the base aggre88ate or place heavy steel plates on subgrade and Ilmit trafficlothe protective cover. 7. Immediately before placing base aggregate and pavement,yremove any accumulation of fine material oll6 Inches torpevent sealln of thanty e subgo a rade surfaceN pr g o POROUSASPHALT - 1. POROUS HOT -MIX ASPHALT Porous hot -mix asphalt Is similar to standardasphalt however the fines ( aggregate fines (particles smaller than No. 30 slave) are reduced, leaving a matrix of pores. 2. AGGREGATEBASE Minimum base depth for structural support should be 12 -Inches. Aggreg9ate: The aggregate should have adequate voids for water storage (20-40 per cent voids Is typical); be dean and have minimal fines (0-2 percent nlrgiadqateraudnaguawth adequate fractured ace to lock together and provide structural support ((o7r percent minimum and 90 percent preferred for Iracturad face). Two example aggregate guidelines are provided below. - WSDOT Permeable Ballast (9-03.9(2)'/. to 2.5 Inches) with a 24nch deep choker course. Install base aggregate In maximum of 8- Inch lifts and lightly compact each IIf . Compact complete aggregate base with a minimum 10 -ton vibratory roller. Use 13#500 Rif plate compactor with a compaction Indicator In places that can't be reached by roller compactor, Make two Passes wth tthle roller In vibratory mode novisible movement of ttic he aggregateode ars Is Com cted aggregate subbase and base hold not M under aggregate delivery bucks or other construction equipment Use back dumping method described herein, 3. CHOKER COURSE - Maximum size -1-12°minus uniformly graded crushed washed stone. - Minimum size - RB US slave arlarger uniformly graded crushed washetl stone. 4. PAVEMENT MATERIALS - Thlcknesw 4 -Inches - Aggregale ggradaton: U,S. Standard Sieve314" APass ng 100 12' g0-100 315" 70-90 4 20-40 8 10-20 40 7-13 200 0-3 o Content: 6.08,5 percent by weight nom% W of Total void space should be approximately 18-25 pa cent per ASTM D3203 (conventional asphalt is 2-3 percent). 5, INSTALLATION - Parous asphalt avemenl Installations use the convenhoneresphald similar procedures ea Muing temperature should be 260-280F, lay down temperature 240-260F, Air temperature should be no lower than 45F end rising. Install porous asphalt system toward the end of construction activities to minimae sedmentroblems. The subgrade can be exca9vateste within 6 -12 -inches of final In titer stages of theads elevation andladingcompleted - Erosion and Introduction of sedment from aurrouncingg land uses should be strictly controlled dudnand after construction.Erosion and segment controls should remain in place until area Is completely stabilized. As wm any paving system rising water In lire underlvIng aggregate base should not be allowed to saturate the pavement - e. GEO FABRIC Overlap adjacent strips of fabric at least 24 Inches. Leave enough fabric to cam letery wrap over small Instellatlons (e.g., sldewalks�or the edge of larger Installations adequately to prevent eedlmenl Inputs Irom atlJscent disturbed areas. Secure fabric outside of storage bed. Following placement of base aggregate and again after la cement of the pavement the filterfabric houlpd be folded over placements end secured to protect Installation from secimenl In uts. Excess filter fabric should not be trimmed until elPa Is fully stabilized STANDARD SlORMWATER NOTES: 7. A preconstruc0on meeting shall be held prior to the start of construction or slaking of the site, The preconstruction meeting shall Include staff Irom stormwater, water an sewer Militias II applicabta. 2. All workmanship and materials shall be In accordance with the Stormwater Management Manual for Western Washington (SWMMWW), other County standards and the most current copy of the Stale or Washinglon Standard Specifications for Road, Badge and Municipal Construction (WSDOT/APWA) In that order. 3. Construction SWPPP consistentwith the requirements set forth in Vol II In the SWMMWW and Includes ell 13 elements or as required In the Construction Stormwater General Permit. BMPs selected for Implementation are lobe approved by Ecology and are to conform to the current Stormwater Management Manual for Western Washington. 4. A Construction Stormwater Pollution Prevention Plan (SWPPP) and a copy of the approved stormwater plans shall be amine at all times when consW ction is In progress. Whenever Inspection and/or monitoring reveals that the BMPs are Inadequate, due to discharge, track out, or potential to discharge, BMPs or design changes shall be implemented as soon as possible. II deficlendes are Identified the following actions shall ba taken by the county. Il shall be al the discretion of the Inspector which action will be taken based on the severity or history of the site. A 1st ecton taken Is a verbal warning to the foreman or person overseeing the site. B, 2nd action taken Is a written Inspection with actions to be taken signed by the foreman or person overseeing the site. C, 3rd actian taken If corrective actions ere not taken, completed or Issues continue to be found will be a written notice and a Stop Work Order shall be posted. 5. Seasonal Work UmitaOons -From October 1 through April 30, pleading, gracing, end other loll disturbing ecevites will not be permitted unless it Is shown to the satisfaction of the County Thal sll4leden runoff will be prevented from leaving Ne site through a combination of the following • Slta conditions Including existing vegetative coverage, slope, soil type, and proximity to receiving waters; and • Umilations on activities and the extent of disturbed areas; and Proposed erosion and sedment control measures The County may expand or restrict the seasonal limitation on site disturbance based on site Inspections, local weather condtions, or other Information. • Il, during the course of any consWction activity or soil disturbance during the seasonal llmilabon period, sit -laden runoff leaving the construction site causes a violation ofthe surface water quality standard; or • II clearing end gracing limits or erosion and sediment control measures shown in the approved plan are not maintained, the County may take enforcement action, Including but not limited to a notice of violation, administrative order, Me/penalty, slop -work order, or correction notice. 6, Exposed soils shall not be left exposed and unworked for more than 2 days between (October 1 -April 30) or 7 days bw eteen (Mayi - Sepl. 301 . 7. Pssura that concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping and mixer washout Is performed offsite or in designated concrete washout areas only. Do not wash out concrete bucks onto the ground, or Into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Refer to the Stormwater Management Manuel for Western Washington for BMP's. Concrete spillage or concrete dscharge to stormwater facilities Is an Illicit discharge, 8. Applicant shall comply with all other permits and other requirements of the governing authority or agency. e, nil storm mains and retentioNdetention areas shall be staked for grade and alignment by an engineering or survey firm licensed to perform such work 10. Storm drain pipe materials shall be as specified In the SWMMWW. Pipe size, slope, cover, etc., shall be as specified In Volume III of the SWMMWW, 11. The storm drainage system shall be constructed according to approved plana on file with the jurisdiwritten approval Any material deviation from the approved plans will require wriapproval Irom the jurisdiction. 12. Special structures, o lfimler separators, and outlet controls shall be installed per plans and manufacturer's recommendations. 13. Washington law requires that the rules adopted by Washington Utilities and Transportation Commission be followed. Those rules are set forth in RCW 19.122 and requires anyone performing any type of digging to call at least two business days beforeFm w digging. Dial 811 or 1-800-424.5555 or visit www.callbeforeyoudg.org. 14. All surveying and staking shall be performed by an engineering or surveying firm capable of performing such work The engineer or surveyor directing such work shall be licensed by the State of Washington. 15. The mlrimum staking of storm sewer systems shall be as follows: Q A Stake location of all catch baslns/manholes and other fixtures for grade and alignment. B. Stake location, size, and depth of retentioNdetention facility. C. Stake finished grade of all stormwater features, Including but not limited to catch baslrdmanhole dm elevations, overflow structures, weirs, and invert elevations of all pipes In catch basins, manholes, and those pipes that daylight 18. Final elevators, locations, slopes, grades, roadway alignments, etc, shall be based an a field survey conducted by a licensed professional surveyor and shall be stamped by the surveyor as a record of the final constructed locallon and elevation of lacllitles shown. 17, Acontnuous toning wire shall be burled the entire length of all stormwater pipe and be located and attached to the top of the pipe. The toning wire shall be 12 gauge insulated green toning wire. The toning wire shall end In calchbasins, manholes, other structures, and be placed In a organized manner on a stainless steel concrete wedge anchor and/or hook within six (6) inches of lid or grate or end of pipe if no structures present I.e., cross culvert with a minimum of five (5) fool coil of wire so itwill not fall off and can be accessed without entering the structure. The toning wire shall be tested for continuity prior to acceptance. All splices will be made with Copperhead SnakeSite connectors or 3M DBR moisture displacement connectors splice kits designed for In- ground use. 18, Underground warning tape shall be placed approximately twelve (12') above the top of pipe indicating stormwater pipe. 19. All culverts shall be a minimum of twelve (120) diameter and of sufficlenl length to provide a minimum 3.1 slope from the edge of the driveway or roadway to the bottom of the ditch. The culvert shall extend one foot outside the driveway or roadway radius before the bevel to allow for dprap armoring to prevent sloughing of the baselcrushed rock Into the ditch. Culverts shall have beveled ends to match the side slope. Ductile Iron pipe shall be cut short to allow for transition to PVC or PE beveled pipe ends that are exposed In open conveyance system, 20. The storm drainage system shall be constructed according to accepted plans on file with the County. Any material deviation from the plans will require written acceptance from the Drainage Manual Administrator or designee. 21. Calchbasln grates shall be directional grates where grade or Slope Is greater than or equal to 1%, 22. A copy of the accepted storm water plans must be on the job site whenever construction Is In progress. 23. All building downspouts on commercial sites shall be connected to the storm drainage system, uniess otherwise acceptable to the County. 24. The contractor shall be responsible for providing adequate safeguards, safety devices, protectve equipment flaggers, and any other needed actions to protect the life, health, and Safety olthe public, and to protect property In connection with the Z performance of work Any workwthin the traveled dght-of-way that may Interrupt normal traffic flow shall require at least one flagger for each lane of traffic affected. A I sections of the current WSDOT Standard Specifications for Traffic Control or MUTCD z shall apply. 25. II shell be the sole responsiblity of the contractor to obtain street use and other related or required permits prior to any construction activity In the County right-of-way. It shall also be the responsibility of the contractor to obtain all required permits prior to any construction. 26. All new storm drain pipelines shall be Closed-circuit television (CCTV) inspected and Air Pressure Tested (APT) by the developer. contractor or applicant prior to paving when practical. Required Pre-Nolifcation The Contractor shall notify the County Storm and Surface Water Utility at 360-867-2099 at least 3 Working Days in advance of the first television Inspection. 27. Thermo -plastic drainage markings are required for all structures In the roadway, Please contact the Storm and Surface Water Utility at 360-867-2099 for marking standards. 28. The Project Engineer shall inspect drainage and erosion control facilities periodically during construction. The Project Engineer shall provide, at a minimum, inspection certification for the drainage and erosion control facilities follovnng any storm event with precipitation equal to or exceeding 2Inches Ina 24-hour period. Failure to submit certification to the County within 24 hours following such an event may result In a stop work order being placed on the project. 29, All castings or structures not In pavement areas, and not in the roadway right-of-way of a paved road, shall beset six Inches (6°) above finished grade. They shall have a cast Iron frame and cover grouted to just under the top of the frame and a concrete pad extending out 2 feet in all drectlons. 30. Pll disturbed areas shall be seeded and mulched or similarly stabilized to the satisfaction of THE City of Yelm. For sites where grass has been planted through hydroseedng, final will not occur until the grass hes been thoroughly established (90% estadlshment), unless otherwise approved by the County. 31. No as or shrubs may be planted vnthln 25 feet of Inlet or outlet pipes or manmade drainage structures such as spillways or flow spreaders. Species with roots that seek water, such as vnllow or poplar, shall be avoided within 50 feet of pipes or manmade structures. 32. TCC 18.16.020 Bonding of drainage Improvements shall not be allowed and facilities will be consWcted end complete prior to final. APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CITY OF YELM APPROVAL EXPIRES: 4 AGENCY N0. 2020.0004 SHEET: 6 OF 17 E/dg N79-0W/19-035/CDs INDEX: 19-035 detdwg JOB: 19-035 > N ry m > � m N, S Q Wpl K U O U O N 4 AGENCY N0. 2020.0004 SHEET: 6 OF 17 E/dg N79-0W/19-035/CDs INDEX: 19-035 detdwg JOB: 19-035 v > r U .. EX. K, BL GAL. SEPTIC �ZOT / _ __.. --- �-�-�-�TANK, BLDG 7 8 2 \ EX. 7,500 GAL. \ / / SEPTIC TANK, BLDG 3 W eXlsTinu uv EX. 8,000 DAL. SEPTIC TANK, BLOG 4 & 59 EX. 2,000 GAL, PUMP CHAMBER SERVING BUILDINGS 1.5 NEW 6,000 GAL STEPTANK / PUMP CHAMBER, TYP CONNECT TO EXISTING FORCE MAIN NEW FIRE HYDRANT S FOC'S NEW PI V, TYP SEWER CLEANOUT,TYP CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COUN TY BM #596 4D CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. 8 CREEK RD. NO. SS -8026, VOL.25, ELEV = 338,31 PG.304 (NGVD 1029) = 20' 2D 10 0 20 4D i w o 0 SCALE: 1" = 20' N N AGENCY NO, 2020.0004 SHEET: ? OF 17 E /dgN19-000/18-035/C0s INDEX: 19-035 utll,dwg JOB; 19-035 i w o 0 N N m � m o x > w w 3 v tii AGENCY NO, 2020.0004 SHEET: ? OF 17 E /dgN19-000/18-035/C0s INDEX: 19-035 utll,dwg JOB; 19-035 12+73.46, 114.26' LT (SPL) INSTALL 4" GV WI POST INDICATOR BLOCKING SOUTH PROPERTY LINE (SPL)= STATIONING LINE 12+93.01, 81.00' L7 (5PL) INSTALL 1-112" WATER METER (BLDG #8) 12+97.01, 79.00' LT INSTALL 314" IRRIGATION METER 12+92.96, 114.31' LT (SPL) CONNECT TO EXISTING 6" WATER MAIN INSTALL 12+92.95, 125.92' LT (SPL) INSTALL 1 • 6"x6" TEE (MJx FL) XMJ) 1•HYDT ASSEMBLY (13+27.85, 125.96' LT (SPL) BLOCKING (CONTRACTOR TO FIELD VERIFY DEPTH 8 FITTINGS REQ'D) CITY OF YELM w VERTICAL DATUM MERIDIAN HORIZONTAL DATUM 10 THURSTON COUN TY BM #596 CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. 8 CREEK RD, NO, SS -8026, VOL.25, ELEV.= 338.31 PG.304 (NGVD 1929) 13+28.43, 128.96' LT (SPL) INSTALL 1 •FDC (BLDG 7) 13+28.43, 124.96' LT (SPL) INSTALL 1 -FDC (BLDG B) 13+g9.78, 46.22' LT (5PL) INSTALL 1 • 1.112" WATER METER (BLDG #7) 13+47.35, 49.21' LT (SPL) INSTALL 1-6"x4"TAPPING SLEEVE 1 - 4" TAPPING VALVE 10 5 0 10 20 SCALE: 1" = 10' FIRE SPRINKLER LINE DCDA INSIDE BUILDING (SEE MECHANICAL PLANS,TYP)13 1J+70.61, 51.71' LT (SPL) NO INSTALL 1 •4" GV WI POST INDICATOR o BLOCKING e1 mO Q z I N it Y mmo x > O� U O �D/1 Q LI.( w N N W N F M joo Nuoim E Ulm " u �1 a3 C,J Z Q m c aJN L �Om 0 0 � � M O W F- w H Q 2 AGENCY NO. 2020.0004 SHEET: 6 OF 17 E ld 9 N 19-00011 &0355/C O sO s INDEX 19-035 util,dwg JOB; 19-035 3 7 y N it Y mmo x > O� U O �D/1 Q LI.( w N N W N F M joo Nuoim E Ulm " u �1 a3 C,J Z Q m c aJN L �Om 0 0 � � M O W F- w H Q 2 AGENCY NO. 2020.0004 SHEET: 6 OF 17 E ld 9 N 19-00011 &0355/C O sO s INDEX 19-035 util,dwg JOB; 19-035 3 7 y Q LI.( w N N W N F M joo Nuoim E Ulm " u �1 a3 C,J Z Q m c aJN L �Om 0 0 � � M O W F- w H Q 2 AGENCY NO. 2020.0004 SHEET: 6 OF 17 E ld 9 N 19-00011 &0355/C O sO s INDEX 19-035 util,dwg JOB; 19-035 3 7 y MS Rusin LETTERS 2-1/2' FIRE DEPARTMENT "AUTO A B 11/Y 11 I/4' IS' 2• 17 I/4' 15'44.4 SPPoNNLER'bmb WLcr casJEcnoN SCHEDULE 40 GALVANIZED STEEL 24' - BD' IB' % IB' X 8' GONG BLOCK SCHEDULE 40 GALVANIZED SRR WRAPPED YAM s uX Pusllc CITY 0 E ,wPRovm Wr DWG. No. FIRE DEPARTMENT CONNECTION oEs uc wa+Ks DIRECTOR PATE DATE YI(D TMD 12/20I6AVED AREATRACER WE MOD CONCRETE LID OR OFOO 910 PAD TOM GRADE BAWSTJ I � `�W�D�IWIPoEN�YA%. J6' IS 0.5' CONCRETE tt 7000 E%CEEDED (WACM VAPoES) WSOE PAVID ROADWAY RUlI>4 ALL VALVES WSi HAVi 14 g1AGE WSUUIED COPPER TRACER WIRE IRD OFF AT VALVE BODY, IXTDADEo W TSxK PVT; PoSER CAIC VALVE SHOWN-9WIAfl PIPE MEN IXTFNDED WS FOOT TOP OF VA1V[ BOX WSTALlAAON REWWED FOR BUf1DULY VALViS YALYC S1EY E%1EN510N LEGEND m VALVE OPERATING NUT OR 1 7/8' % 1 7/6• % Y NICM GRADE SSR WELDED TO RISER N0� SHAFT. m 3/I6' Th4 % 5 I/5' CIA STEEL GUIDE A11 YIELDS To SHAFT SHALL BE I//' FRlil ERAS WELDED TO RISER SHAFT. WELD ALL AROUND, m 2•%Z'% 3/I6' SWARF STRUCTURAL STEEL IUBNO TO FIT OPFAAAHC NUT. IfNGM AS REOUOiED. STANDARD VALVE BOX AND HYDRANT LOCK DWG. H0. TOP NEW HYDRANT LOCK I- 11WT5 OF PAYMENT PAINT HYDRMT SUN WEATHER SHIEID YELLOW WGH GRADE ENAMEL � IJS12 BONNET 1 I/2' HOSE CONNCC WITH THREADS I 4 1/2• STEAMER CONNCCng4 s - WITH NST THREADS h 5' STORZ � n ADAPTER SME S-37 W/SC CAP 8• STANDPIPE 3' YINIYUu EACH PIPE JOWT 6' /1106 EBAA IRON, INC. CIA55 52 DUC11lE ptON PIPE r To IENGM 6' GALE VALVE, R % YJ AE NOS BELOW VAPoES I -4'%8'%I6' CONQ+ETE BLOCK 1 HYDRANT SHOE BACKFRL TO TOP OF DRAW RING HOUSING BOLTS YAM Z' WASHED BOLI( AS 9WYM PLASTIC BAIiWFA BETMEEN SHEET OF II YB. PLASTIC OR CON- SIRUCDON THRUST BLIXJ( AND LEE FABRIC, CON:RWC 2' WASHED ROCK CONCRETE THRUST BL00(' CAST -IN-PLACE AGAINST N41ES_ FlTTINO ONLY I. HYDRANTS SHALL � LOCATED W ACCORDANCE WITH SECTION 6.060. W ADDITION, A WNIYUII THREE FOOT RADIUS UNOBSTRUCTED WORKING AREA SHALL BE PPONDm AROUND ALL HYDRANTS. Z. HYDRANTS SHALL t# DRESSER Y 8 H RECANT SME 129, CLOW WDALUON OR AYEPoCM AN( SUMS 2780 OR WD1FA CENTURION J. CATS VALVES SHALL BE RESRID4T WEDGE LABS YAM O-RING SEALS VALVE ENDS SHPll BE MECHAMCAL AMT BY M51 FLANGES. VALVES SHALL CONFORM i0 AYAYA 509-80. VALVES SHALL BE W0.LFR MBH. KENNEDY, CLOW fl/W OR WAlERWS SERIES 500. 4. FIRE HYDRMf LODE PAYMENT IS REIXMSO Ott WILL ORDER AND INSTAII, � HYDRANT OFFSETBLOCK (TYP) SEE VALLA: BO% AND VALLA: S1EM OCTAIL- 4-II u PUFIIJC WORK9 WRECTDR PATE 4"� FIRE HYDRANT �wD DrMMYD c DAIi/2011EEB qbbbbb� WAIL -3 �mmow2w kw TOP NEW TOP EW TOP NEW WTE •SIDE VIEW SIDE NEW SIDE NEW LEE [ROSS GATE VALVE HOPoZ. BENDin r �C� WJE ,�gaCP :+'1 •ti (+" .';': IEE YAM CROSS wM CRO55 WITH RUG OR CM PLuc Ruc Rucs 45' - 90' VTRIICAL BEND rypTE4 I. CONCRETE R9NIST BLOCKING TO � PgF1E0 ACAWST UNDISTURBED EMM. 2 PLASTIC BAPoIRA SHALL BE PLACED BE- TWEEN ALL THRUST BLOCKS @ FlTIWGS I Mg10R BERM SHALL DE s/B' WNWNIY DlnuElrn. ^{ (�` APPROVED BY DWG. Ha STANDARD BLOCKING DETAIL oEs� Yn �6 DIRECTOR DATE DATE uN TAP �I p' ryp CONCRETE MRusr 2 TYP F S � TAPX WC VALVE R MJ STAINLESS STEEL TAPPING SLEEVE VALVE No SLEEVE SMALL BE gtOUND SUPPORTED AND LED AS SHO»N BROW-RQI1. CAIS VALVE RaYJ TEE BACKFILebb I/1 DIAMETER of PIPE / •: LED OENStt BAIXFHLJ 1- 2' ��:�: CONTROLmmmmff POURED IWOM OF TRENCH SOW BNNJf SUPPORT CONCRETE THRUST BLOCK Immmmm NOTES I. II YIL PLASAC OR CONSTRUCTION FABRIC STALL BE WRMPED MWNO PIPE AND FliANGS BEFORE THRUST BLOCK AND BACKFILL ARE POURED. 1. 4J CUf IN LEES SHALL NOT BE PERMITTED. 3. SUPPONT VALVE AND REEVE CONTINUOUSLY MRWGH INSTALLATION. CITY 0 YEL APPROVED BY DWG. LA0, PUBLIC CONNECTION TO EXISTING MAIN 90' BEND ' 45' BEND 22-I/2' BEND II -1/4' BFJq DEAD END OR IEC /' 3,600 2,000 1,000 500 2.600 fi• ' 8,000 4,400 2.100 1,200 5.700 8' I/,700 7,700 4,000 2,000 10,100 10' 21,]00 12,100 8,200 1,100 15,600 12' 71,000 17,400 4900 4,500 22,700 14' 47,600 27,600 12,100 6,100 70,800 I6' 57,000 70,600 15.700 7,900 40,700 ❑ m w x > w w U � N w O 3 v O N O U O vv uKo loco is Iz/zo+s WORKS dNECTOR DATE DAS4-tO YKD IJKD .EG 12/2016 THRUST LOADS 11RT15T AT FITTINGS W POUNDS AT 200 POUNDS PER SQUARE INCH OF WATER PRESSURE pp NO1ES I. BLOCpNG SHALL BE CEMENT CONCRETE CUSS 3000 FIGURED W PLACE ACAWSi UNWSnREBED EMM. FITTING SHALL BE ISOLATED FROM CONCRETE THRUST BLOCK YAM PLASTIC OR SNAAR MATERIAL 2 TO OEIERWNE THE BEARING AREA OF THE THRUST BLOCK W SWARF FEET fSF.). E%ANPILE : 12' - 90' BEND W SAND AND CRANI. 72,000 LBS - 7000 L8/1F. _ 10.7 F. OF AREA a MUS MUST BE ADJUSTED FOR OTHER PPE 9IE, PRESSURES AND SOIL CONDITIONS. 1. BLOCwWO SHAH BE ADEQUATE TO IWMsfAW FULL TEST PRESSURE AS W0.1 h5 TO CONIWUWAY WITHSTAND OPERATING PRESSURE UNDER ALto OD L CONDITIONS OF SERVICE SAFE MwgnUSBuawc EOAD[s AI �RCOY FZ SER THE %PE E7ffEDS 2�EI POUNDS PER SOIL �11aflE cool YUCK, PEAT 0 SOFT qAM 14000 SAND 2,oso SANG k CAAVII 7,000 SAIW & AXiAVE1 4.000 cEUD4TFn NIM CLAY HARD SHALL 10000 CIMOF APPROVED By Dwa Na THRUST LOADS PUWLIC WdiK6 DIRECTOR DATE DAh4.14 a%� " PIPE DIAYEiER 90' BEND ' 45' BEND 22-I/2' BEND II -1/4' BFJq DEAD END OR IEC /' 3,600 2,000 1,000 500 2.600 fi• ' 8,000 4,400 2.100 1,200 5.700 8' I/,700 7,700 4,000 2,000 10,100 10' 21,]00 12,100 8,200 1,100 15,600 12' 71,000 17,400 4900 4,500 22,700 14' 47,600 27,600 12,100 6,100 70,800 I6' 57,000 70,600 15.700 7,900 40,700 ❑ m w x > w w U � N w O 3 v O N O U O �D 12/2ols PIPE DIAYEiER 90' BEND ' 45' BEND 22-I/2' BEND II -1/4' BFJq DEAD END OR IEC /' 3,600 2,000 1,000 500 2.600 fi• ' 8,000 4,400 2.100 1,200 5.700 8' I/,700 7,700 4,000 2,000 10,100 10' 21,]00 12,100 8,200 1,100 15,600 12' 71,000 17,400 4900 4,500 22,700 14' 47,600 27,600 12,100 6,100 70,800 I6' 57,000 70,600 15.700 7,900 40,700 APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CITY OF YELM APPROVAL E)cPIRES�, r LA0. 2020.0004 SHEET: O7 EldgN19-000/19-035/COs x l9-035 deLdVAB ❑ 19-035 rn Q � (n � J z J a 3 } � W Q m � O m ❑ m w x > w w U � N w O 3 v O N O U O r LA0. 2020.0004 SHEET: O7 EldgN19-000/19-035/COs INDEX: l9-035 deLdVAB JOB: 19-035 Q � (n � J z J a 3 } � W Q Q � O ILL! w � U N m AGENCY LA0. 2020.0004 SHEET: B OF 17 EldgN19-000/19-035/COs INDEX: l9-035 deLdVAB JOB: 19-035 11+89.20, 143.44LT (SPL) CONNECT TO EX, 6" SEWER LATERAL INSTALL 1 - 6"z6" WYE FL 333.79 ABANDON EX, 6" LATERAL WEST OF CONNECTION (CONTRACTOR TO FIELD VERIFY DEPTH & FITTINGS REO'D) 11x87.02, 142.21' LT (SPL) INSTALL 1 • SEWER CLEANOUT RIM 341* FL333.81 32 LF 6" PVC SEWER LATERAL Q 2% 11x57.56, 141.60' LT (SPL) INSTALL 1 • SEWER CLEANOUT RIM 340.5* FL 334.45 23 LF 6" PVL SEWER LATERAL Q 2Y 11+b8.2i, 124.&1' LT (BPL) � CONNECT EX. fi" PVC / LATERAL TO NEW e" PVC / FL 334.84 ABANDON EX. LATERAL / EAST OF CONNECTION / (CONTRACTOR 70 FIELD VERIFY L DEPTH & FITTINGS REO'D) 11+65.11, 119.93' LT (SPL) �,p INSTALL_. 1 -SEW ER CLEANOUT L RIM 341t > FL 334.86 12+ge.46. 146.43' LT (SPL) SOUTH PROPERTY LINE (SPL)= STATIONING LINE 12x83.15, 91.81' LT (SPL) CONNECT TO EXISTING 3" FM SEE DETAIL SHEET 12 12+63.92, 146.53' LT (SPL( CONNECT 70 EXISTING 3" FM SEE DETAIL SHEET 12 12+62.10, 145.91' LT (SPL) INSTALL 1 -STEP SERVICE BOX 13#36.68, 32.27' LT (SPL) SEE DETAIL SHEET 12 INSTALL 1 - 8,000 GAL STEP TANK I PUMP CHAMBER G DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS RIM 340 ...t.... ___.__..._._.. FL 338.89 CITY OF YELM O O x VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COUN TY BM #596 CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GP52AT INT. 103RD AVE.&CREEK RD. NO, SS -8026, VOL25, ELEV.= 338.31 PG.304 (NGVD 1929) 30 LF 8" PVC SEWER LATERAL Q 2Y 22 LF 6" PVC SEWER N LATERAL Q 2Y O 0 a QZQ,, 13x76.60, 32.23' LT (SPL) F INSTALL 1 •SEWER CLEANOUT RIM 379.5 FL 734.49 89°17'12" o x W y u i m w m x > (in 9� w U 111 W o O U o W n rn W } Q `1 W U GJ N Z g y� III AGENCY N0. 2020.0004 SHEET: 1U OF 17 E/dgN19-000/13D35/CDs INDEX: 19-035 utll.dWg JOB: 19-035 W n rn W } Q `1 W U GJ N Z g y� III AGENCY N0. 2020.0004 SHEET: 1U OF 17 E/dgN19-000/13D35/CDs INDEX: 19-035 utll.dWg JOB: 19-035 SEE THU NOTE: INSTPLL %ER%ES ITEMS PER %ER%ES INSTALLATION SPECIFICATIONS, INSTALL ORENCO ITEMS PER ORENCO INSTALLATION SPECIFICATIONS. N0, DESCRIPTION I %ER%ES SINGLE WALL FRP TANK, 6' DIA, 6,000 CAL. 2 %ER%ES PRECAST DEADMAN SYSTEM W/ HOLD DOYiN STRAP AND TURNBUCKLE ASSY. 3 124' FRP OPENING 4 30" FRP OPENING W/ INTERNAL FLANGE 5 6" SCH. 40 PVC IN PIPING W/ SANITARY TEE 6 FULL HEIGHT FRP BAFFLE MALL 7 ORENCO "DIDTUBE• EFFLUENT FILTER (BAFFLE WALL CROSSOVER), ORENCO FT0646-36 9 24" RIBBED PVC RISER W/ FRP UD 9 30" RIBBED PVC RISER W/ FRP UD ORENCO ' EFFLUENT k FLOAT SWITCH ASSEMBLY Thls drawing is for illustrative purposes only. Consult n/\l�i�h (\a]I en��gineer�for /s\p�e�c(i\fi]cII ap��Cplications. UULJLJ UU ULJ�a CORPORATION ILLUSTRATIVE APPLICATION DRAWINGS Small Commercial Septic or STEP Tank OSI Pump out w/Filter Dual Compartment 5-00 I 1. PUMPS ARE DESIGNED TO OPERATE IN A DUPLE% CONFIGURATION SUCH THAT BOTH PAIRS OF PUMPS LAN OPERATE IN A LEAD/LAG CONFIGURATION WITH THE POTENTIAL FOR BOTH PAIRS TO BE RUNNING AT THE SAME TIME DURING HIGH FLOW CONDITIONS. 2. AN ALTERNATING DEVICE SHALL BE PROVIDED WITH THREE POSITIONS: PUMP 1. PUMP 2, ALTERNATING PUMPS I & 2. THE STANDARD OPERATION WILL BE IN THE ALTERNATE POSITION, WITH THE OTHER TWO POSITIONS RESERVED FOR ONE PUMP TO BE TAKEN OFF LINE DURING MAINTENANCE. 3. THE PUMP CONTROLLER SHALL BE EQUIPPED WITH A CITY OF YELM APPROPRIATE SIGNAL SENDING TELEMETRY UNIT. THE TELEMETRY UNIT SHALL SEND STEP STATION STATUS AND ALARM INFORMATION TO THE CITY'S RECEIVING UNIT. ALL TELEMENTRY EQUIPMENT SHALL BE COMPATIBLE WITH CITY OF YELM'S EQUIPMENT. CONTRACTOR SHALL CONTACT THE CITY STAFF FOR EQUIPMENT SELECTION. 9. EACH PUMP SHALL BE SUPPLIED WITH A SEPARATE SHUTOFF VALVE AND UNION TO FACILITATE REMOVAL OF INDIVIDUAL PUMPS. 5. PUMPS SHALL BE ORENCO P20 05 11 OR APPROVED EQUAL. EACH PAIR SHALL INCLUDE PROVISIONS FOR A 3 0 SECOND DELAY BETWEEN PUMP STARTS, 7. ALL ELECTRICAL CONDUITS SHALL BE PVC COATED RMC RIDGED WITH POLYETHYLENE INNER COAT AND SEALED AND SIZED FOR 10, 520-204 NOTE' SITE SPECIFIC DATA ( 0) MUST BE FILLED IN BY SPECIFIER, OWNER OR INSTALLING CONTRACTOR. ACCESS OPENING DIA. 24" i 2" STAND-OFF SUPPORT BLOCKrPUMP 7" INLET PIPE DIA, 6'" I--12" INLET ELEV. 36'" TER ALARM 'ON' PUMP 'OFF' REDUNDANT 'OFF' INLET PIPE FROM e 59" BOTTOM OF TANK LOW WATER ALARM (INVERT ELEVATION) 271/8" CORPORATION FILE INLET SANITARY TEE THROUGH ACCESS OPENING "` 5-00 a NO. S10-824 MANHOLE/TANK COMPACTION & BEDDING NOTE:_ 1. MH & TANKS SHALL BE BEDDED ON 6" SAND OR PEA GRAVEL 2. BACKFILL AGAINST SIDE SHALL BE COMPACTED IN 6" LIFTS TO THE SAME OR GREATER COMPACTION THEN SURROUNDING AREA THE TANKS SPECIFIED ARE MEANT TO DENOTE REQUIRED TANK VOLUME/CONFlCURATION THE CITY OF YELM HAS SPECIFIC TESTING REQUIREMENTS FOR L T.E.P. HOLDING TANKS, SPECIOF YELM SHALL BE REVIEWED AND APPROVED BY CITY OF YELM PRIOR TO USE, SHOP DRAWINGS SHALL BE SUBMITTED FOR EACH COMMERCIAL P, TANK. TANK DIMENSIONS, INCLUDING BAFFLE WALL CONFIGURATION, BAFFLE WALL PENETRATIONS AND RISER LOCTIDNS AND HEIGHTS, SHALL BE DEPICTED. CONTRACTOR SHALL SUBMIT STRUCTURAL CALCULATIONS ON TANK PROPOSED FOR USE AND SHALL CONDUCT AND PASS A LEAK TEST, PRESSURE TEST AND FINAL INSPECTION PER CITY OF YELM REQUIREMENTS. TELEMETRY FUNCTIONS ° HIGH -HIGH LEVEL 2 PUMP RUN •HIGH WET WELL • I PUMP FAIL • I PUMP RUN • 2 PUMP FAIL PANEL TO SE CONSTRUCTED ACCORDING TO ORENCO SPECIFlCATIONS, AND SHOULD BE CONSTRUCTED BY ORENCO. THE ELECTRICAL PANEL SHALL BE PURCHASED AS A PACKAGE STATION, ASSEMBLED IN THE SHOP BY A UL LISTED 509 INDUSTRIAL MANUFACTURER. A FIELD BUILT STATION WILL NOT BE PERMITTED. THE CONTRACTOR SHALL SUBMIT ELECTRICAL MATERIAL SPECIFICATIONS TO THE CITY OF YELM FOR APPROVAL PRIOR TO INSTALLATION. ELECTRICAL CONTRACTOR IS RESPONSIBLE FOR THE INSTALLATION OF ALL CONDUIT, CONTROL PANEL, AND CONTROL PANEL CONC PAD PROPERTY OWNERS ARE RESPONSIBLE FOR SUPPLYING POWER (INCLUDING BACKUP POWER IN THE EVENT OF AN OUTAGE). THE POWER TRANSFER SWITCH FOR AU%ILIARY POWER SHALL BE LOCATED OUTSIDE OF THE CONTROL PANEL AND ACCESSIBLE TO THE PROPERTY OWNER. OPERATION &MAINTENANCE NOTES' THE CONTRACTOR SHALL SUPPLY THE CITY WITH 3 SETS AND THE PROJECT ENGINEER WITH 1 SET OF THE MANUFACTURERS OPERATION & MAINTENANCE A COM MANUAL FOR THE PUMP STATION ALONG WITH A COMPLETE SET OF ELECTRICAL DRAWINGS FOR THE STATION. TELEMETRY NOTES: LIFT STATION TELEMETRY WILL CONSIST OF A RUGID RUGS PLC, 12 -VOLT ISOLATED POWER SUPPLY, CELLNET, UTILNET IWR SERIES 3000, 900 MHZ RADIO, ANTENNA CABLE WITH LIGHTNING ARRESTOR, AND 6D8 GAIN STICK ANTENNA THAT WILL BE SUPPLIED AND INSTALLED BY THE CONTRACTOR, ALARM AND STATION STATUS POINTS AND ASSOCIATED WIRING COLORS SHALL CONFORM WITH THE LIST PROVIDED TO THE DEVELOPER. THE TELEMETRY WILL BE ENCLOSED IN A NEMA 1 ENCLOSURE WITHIN THE ELECTRICAL CABINET. PRIOR TO ORDERING THE ABOVE EQUIPMENT, THE CONTRACTOR WILL CONTACT THE REMOTE SYSTEM TECHNICIAN, CITY OF YELM DEPARTMENT OF PUBLIC WORKS, FOR COMPLETE ORDERING SPECIFICATIONS FOR THE ABOVE TEKEMETRY. NORMAL LEAD TIME IS 12 WEEKS.THE UNIT SHALL BE CAPABLE OF SENDING THE FOLLOWING SIGNALS TO THE CITY OF YELM: HIGHLEVEL ALARM, PUMP #1 RUN/FAIL, PUMP �/2 RUN/FAIL, POWER FAILURE, INTRUSION ALARM, COMMUNICATION FAILURE, HIGH LEVEL ALARM IN '"XERXES" 25,000 GAL TANK, ORENCO FILTER INSTALL PER MANUFACTURER'S INSTRUCTIONS 24'" ACCESS OPENING DIA. FULL HEIGHT FRP BAFFLE YJALL BAFFLE WALL CROSS OVER w 0 520-204 NOTE' SITE SPECIFIC DATA ( 0) MUST BE FILLED IN BY SPECIFIER, OWNER OR INSTALLING CONTRACTOR. ACCESS OPENING DIA. 24" i 2" STAND-OFF SUPPORT BLOCKrPUMP 7" INLET PIPE DIA, 6'" I--12" INLET ELEV. 36'" TER ALARM 'ON' PUMP 'OFF' REDUNDANT 'OFF' INLET PIPE FROM e 59" BOTTOM OF TANK LOW WATER ALARM (INVERT ELEVATION) 271/8" CORPORATION FILE INLET SANITARY TEE THROUGH ACCESS OPENING "` 5-00 a NO. S10-824 MANHOLE/TANK COMPACTION & BEDDING NOTE:_ 1. MH & TANKS SHALL BE BEDDED ON 6" SAND OR PEA GRAVEL 2. BACKFILL AGAINST SIDE SHALL BE COMPACTED IN 6" LIFTS TO THE SAME OR GREATER COMPACTION THEN SURROUNDING AREA THE TANKS SPECIFIED ARE MEANT TO DENOTE REQUIRED TANK VOLUME/CONFlCURATION THE CITY OF YELM HAS SPECIFIC TESTING REQUIREMENTS FOR L T.E.P. HOLDING TANKS, SPECIOF YELM SHALL BE REVIEWED AND APPROVED BY CITY OF YELM PRIOR TO USE, SHOP DRAWINGS SHALL BE SUBMITTED FOR EACH COMMERCIAL P, TANK. TANK DIMENSIONS, INCLUDING BAFFLE WALL CONFIGURATION, BAFFLE WALL PENETRATIONS AND RISER LOCTIDNS AND HEIGHTS, SHALL BE DEPICTED. CONTRACTOR SHALL SUBMIT STRUCTURAL CALCULATIONS ON TANK PROPOSED FOR USE AND SHALL CONDUCT AND PASS A LEAK TEST, PRESSURE TEST AND FINAL INSPECTION PER CITY OF YELM REQUIREMENTS. TELEMETRY FUNCTIONS ° HIGH -HIGH LEVEL 2 PUMP RUN •HIGH WET WELL • I PUMP FAIL • I PUMP RUN • 2 PUMP FAIL PANEL TO SE CONSTRUCTED ACCORDING TO ORENCO SPECIFlCATIONS, AND SHOULD BE CONSTRUCTED BY ORENCO. THE ELECTRICAL PANEL SHALL BE PURCHASED AS A PACKAGE STATION, ASSEMBLED IN THE SHOP BY A UL LISTED 509 INDUSTRIAL MANUFACTURER. A FIELD BUILT STATION WILL NOT BE PERMITTED. THE CONTRACTOR SHALL SUBMIT ELECTRICAL MATERIAL SPECIFICATIONS TO THE CITY OF YELM FOR APPROVAL PRIOR TO INSTALLATION. ELECTRICAL CONTRACTOR IS RESPONSIBLE FOR THE INSTALLATION OF ALL CONDUIT, CONTROL PANEL, AND CONTROL PANEL CONC PAD PROPERTY OWNERS ARE RESPONSIBLE FOR SUPPLYING POWER (INCLUDING BACKUP POWER IN THE EVENT OF AN OUTAGE). THE POWER TRANSFER SWITCH FOR AU%ILIARY POWER SHALL BE LOCATED OUTSIDE OF THE CONTROL PANEL AND ACCESSIBLE TO THE PROPERTY OWNER. OPERATION &MAINTENANCE NOTES' THE CONTRACTOR SHALL SUPPLY THE CITY WITH 3 SETS AND THE PROJECT ENGINEER WITH 1 SET OF THE MANUFACTURERS OPERATION & MAINTENANCE A COM MANUAL FOR THE PUMP STATION ALONG WITH A COMPLETE SET OF ELECTRICAL DRAWINGS FOR THE STATION. TELEMETRY NOTES: LIFT STATION TELEMETRY WILL CONSIST OF A RUGID RUGS PLC, 12 -VOLT ISOLATED POWER SUPPLY, CELLNET, UTILNET IWR SERIES 3000, 900 MHZ RADIO, ANTENNA CABLE WITH LIGHTNING ARRESTOR, AND 6D8 GAIN STICK ANTENNA THAT WILL BE SUPPLIED AND INSTALLED BY THE CONTRACTOR, ALARM AND STATION STATUS POINTS AND ASSOCIATED WIRING COLORS SHALL CONFORM WITH THE LIST PROVIDED TO THE DEVELOPER. THE TELEMETRY WILL BE ENCLOSED IN A NEMA 1 ENCLOSURE WITHIN THE ELECTRICAL CABINET. PRIOR TO ORDERING THE ABOVE EQUIPMENT, THE CONTRACTOR WILL CONTACT THE REMOTE SYSTEM TECHNICIAN, CITY OF YELM DEPARTMENT OF PUBLIC WORKS, FOR COMPLETE ORDERING SPECIFICATIONS FOR THE ABOVE TEKEMETRY. NORMAL LEAD TIME IS 12 WEEKS.THE UNIT SHALL BE CAPABLE OF SENDING THE FOLLOWING SIGNALS TO THE CITY OF YELM: HIGHLEVEL ALARM, PUMP #1 RUN/FAIL, PUMP �/2 RUN/FAIL, POWER FAILURE, INTRUSION ALARM, COMMUNICATION FAILURE, HIGH LEVEL ALARM IN '"XERXES" 25,000 GAL TANK, ORENCO FILTER INSTALL PER MANUFACTURER'S INSTRUCTIONS 24'" ACCESS OPENING DIA. FULL HEIGHT FRP BAFFLE YJALL BAFFLE WALL CROSS OVER FLEXIBLE CONNECTOR � SUPPORT PIPE, NOT ATTACHED TO TANK BOTTOM BAFFLE WALL & EFFLUENT FI L TER DETAIL O APPROVED FOR CONSTRUCTION ` BY; DATE: 2020.0004 AGENCY NO. DEVELOPMENT REVIEW ENGINEER, CITY OF YELM SHEET: 11 LO C E/dgN19-000/19-035/C Ds INDEX 19-035 deLdvg APPROVAL EXPIRES: JOB: 19-035 = w o 0 � N H m � m w m o x > Q m O U o APPROVED FOR CONSTRUCTION ` BY; DATE: 2020.0004 AGENCY NO. DEVELOPMENT REVIEW ENGINEER, CITY OF YELM SHEET: 11 LO C E/dgN19-000/19-035/C Ds INDEX 19-035 deLdvg APPROVAL EXPIRES: JOB: 19-035 SPLICE ro EATsnNc 14 GAUGE TONING WIRE TO STEP TANK CaDtECT TO / EMSIING PYC J 1' OR 1' CHECK VI SFRWCE LIKE I' OR 2' KDI BALL VALVE, SL E IK 7 IN�IE& 1. ALL %RVICE LWC CARSON BOXES SHALL BE LOCATED 4' FROM EDGE OF CURB TO CENTER OF CARSON BOX W PUNTER STRIP ON BOTH SIDES OF ROADWAY. 2 GANG CARSON BOXES SHALL GE LOCATED 3' APART TO CENTER OF BOXES J. BALL AND CHECK VALVES TO BE INSTALLED N CARSON BOXES ACCORDING TO DRAWING 4. NO THREADED CONNECTIONS IN SERVICE LINES UNLESS PRE -APPROVED BY THE DIRECTOR OF HIS/HER DESIGNER. 1'OR 2' 40 PUBLIC SEWER 13' /A/A O O tD' � s/a. SEE OCTJJL 7-0 1-1 4' S[AL MIIMyUBUC SEWER RECESSED RIVING HANDLE TYPE UD MRH CRY DF ASPHALT L SEWER $TAMPED IN UD Y MIN. NMA FOR PATCI 2-1/2' MIN, HUA DNISN GRADE PARE RUN s'.s•Ne• SEWER cOwERgAL CONCRETE PAD �V A10 AWC COPPER I JORDAN IRON FEET OUTSIDE PAVED AREA 7RFNCX BOTTDY SEAWa -CARSON WDCOVER MODEL N0. 14198 WITH BOLTED HINGED COVER OR CONAL CO4ER MARKING To READ 'SEWIT' (USE IN NON-BLAFRC AREAS) 14 GA OF HEAVY INSULATED DIRECT BURY COPPER TONING WIRE ALL TONING WIRE SPLICES SNAIL BE CONNECTED BY USING D.B.Y. KITS MANUFACTURED BY 3M PYC SWING CHECK � YN BALL " SL 1'OP 2' KEN BAVALVL ArS I' OR 2' PVC NPPIE. A Y raR2'.uAwl RmUCWC 7EE A w OR PIPE Rwxr-a-w,LY PARE RUN UIE PRIVATE SEWER t VALVE BORES t SHALL EAST A10 AWC COPPER I JORDAN IRON FEET "Rics (ION ON 350 ® te'1 OROLYMPIC ON ` FO DA VAULT INSTALLATIONS 14 GAUGE I te') PWAMtft�m RECESSE I TYPE U WITH CLEANDU ssW 1 I �D WISHED m PRIVATE CLEANOUT DETAIL N.T.3 RESTORATION SURFACE SEE '\ RESTORATION TABLE ABOVE SEE RESTORATION TABLE 1 , BACKFILL E STEEPRESTORATION TAM MAINTAIN SUE SLOPE AS AS POSSIBLE SEWER LINE PIPE BEDDING FOR FLEXIBLE PIPE SHALL BE SAND 660 OR ASo\\i,\ �PROVED BY DESIGNER SITUATIONS `�.�PIPE O.D. DIRECTOR OR ;s MAY REQUIRE RESTORATION TABLE 1 Soff� WXROR CONSENTS/ OTHER WIN MIND (M 40 WIN M A TOP DOWP�T TO 851 mmirvsmicm� Omm, TO CSBC m CRUSHED SURFACE BASE COURSE CSTC m CRUSHED SURFACE TOP COURSE [Nkfa s n TYPICAL PIPE TRENCH ALARM HIGH LLVD. 6' UG ON/OFF (4.5' DRAMDOMN ON TO OFF) 6' (4.5' DRAGOOYM�aN f0 �� LOW LEVEL ALARM 6' REDUNDANT CET o 0 0F4 kcom SETTING STEP 6' TIN BEDDING 25' N0. 6' 6' NATIVE OR sDEcr BACKFEL AS DIRECTED BY ENGINEER. GRADE 12 NO7E5 WN. PG GRAVEL AROUND FIBFA(7A5$ TANKS, PER MANUFACTURER. 2 6' MW. SAND AROUND ALL APPURTENANCWN ES APPPOVED BY DWG. NO. FIBERGLASS TANK BEDDING PUBLIC WORKS gRECTgE DA,E DATE 1-11 IABIE FOR FEEDER (SEE SPEDFlGAIION$ Fag AWIIIDNAL PARE RUN WIPE 9ZE M24 2 DISTANCE (12 AWG C RIPER 150 FEET A10 AWC COPPER 250 FEET AYD COPPER 350 FEET INEVNYAIRMJ. 5' FINTFNED ON PANEL FROM POWFA SOURCE J/4' CONDUIT W APPROPRIATELY 9ZED PER LAd ELECTRICAL CODE P 92C YAY VARY DEPF4AIWC W APPLICATION. ', TYPICAL PUMP CONTROL PANEL 5-6 D MKD M 10/2019 ED FlMSHEO GRADEWATER TIGHT LD 12 OF 17 EldgN19-0 24' PVC PoSFA PATH x PUMP VAULT RISER ❑ JOB; WATER RCHT LD I 30' RISER MALL BE N ON ` 4 GAUGE VAULT INSTALLATIONS 14 GAUGE I I4 TONING TYRE t0 IOIeNG WINE � To �I - I SERVICE BOX ssW 1 7 m - > 600 I 1 2 PART USE ORtlNO � GAL I 1 TANK To RISER ❑ m ❑ ADAPTER FOR > Z I CONCRETE TANKS OR 4'F�ONFlCE I APPROVED EWAL Ili I PUMP ASSEMBLY, SEE DWG N0. 5-9 2400 1 1 O GAL AFFEE I � (NOTE I N 1) L__J } VOIUME J VDLUM 6' MEN BEDDINGVARIESmmmm NO ESED I. DELETE BAFFLE FOR A 3000 GALLON TANK( UTILIZED AS A TRIPLEX PUMP VAULT, Z. THE OYNO WALL RENEW TOLERANCES IN EXCESS GE DIIAEHSONS SOWN. 3. 1HE iPoPIE% PUMP VAULT REQUIRES TWO VAULTS AND TWO COMPLETE RISERS ONE VAULT CONTAINS FLOATS AND ONE PUMP, THE SECOND VAULT CONTAINS TWO PUMPS F YE APPROWD BY DWG NO. 000 GALLON STEP TANKIPUMP �� PUIIUC NVRKS DIRECTOR DAM I� TANK "WKo "MKD OMu DA 0/EDI9 L2 ED x 12 OF 17 EldgN19-0 W779-075ICDs x w ❑ JOB; RISER AND lD MALL BE N ON A11 PUMP VAULT INSTALLATIONS Y 7 m > � ❑ m ❑ x > Z Z Y Ili O Q � U N 4a` I.L. ILI�LI 1— N Z o m Q � N n m ❑O N Wm D C"I � ? Q m c QJq L �Om o d � � m Z z p� F f" a x FIBERGLASS ID WITH STAINLESS STEEL BOLTS AND NEOPRENE CASKET Tri 5' 4W IMP. 1'1:1/4' ALxwv L U05 � • MW y RRISN GRAD[ AONE f0 NAT .. ,W �(T1P.) � NAIVE 14 GAUGE COPPER DIRECT PVC RISER, cRanE BURT TarBwc WRc. 2'-0' ORENCO SHINS, LA0. Wro RISER MC., ON EQUAL B4iL' N0, 2020.0004 SHEET; 12 OF 17 EldgN19-0 W779-075ICDs INDEX: t9-035 tleLdWg JOB; RISER AND lD MALL BE JO' ON A11 PUMP VAULT INSTALLATIONS ET3]:U15L1:T1 RISER (NON -TRAFFIC RATED) APPROVED FOR CONSTRUCTION BY; DATE' DEVELOPMENT REVIEWFNGINEER, CIN OF YELM APPROVAL AGENCY N0, 2020.0004 SHEET; 12 OF 17 EldgN19-0 W779-075ICDs INDEX: t9-035 tleLdWg JOB; 19-035 YELM GREK APARTM EENITS 1651 1 CREEK ROAD, YELM, WA 98597 WOODLAND MEADOWS 1LLC 2826 E. FOURTH PLAIN BLVD VANCOUVER, WA 98661 y 1• CITY OF YELM eq „ w m VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COON TY BM #596 CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. & CREEK RD. NO, SS -6026, VOL -25,25, ELEV,= 338,31 (NGVD 1929( PG, 304 THIS ORAWI NG DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS CERTIFIED BY HATTON GODAT PAN7IER ANY ALTERATIONS 70 THE DESIGN SHOWN HEREON MUST BE REVIEWED AND APPROVED BY HATTON GODAT PANTIER. NOTE: THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR SHALL VERIFY ALL UTILITY LOCATIONS PRIOR TO CONSTRUCTION BY CALLING THE UNDERGROUND LOCATE LINE AT 1-800-024-5555 A MINIMUM OF 48 HOURS PRIOR TO ANY EXCAVATION. TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT, APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CIN OF YELM APPROVAL EX U E O o m n m } o x > N Q W � U ❑ U O N AGENCY NO. 2020.0004 SHEET: 19 OFA EldgN19-W 0119-035/COs INDEX: PIRES: JOB; 19035 3 x p AGENCY NO. 2020.0004 SHEET: 19 OFA EldgN19-W 0119-035/COs INDEX: PIRES: JOB; 19035 3 x YELIM GREEK APARTMENTS 1651 1 CREEK ROAD, YELM, WA 98597 20 10 0 20 4D ^" U � SCALE: V=20' GPS 2 AT INT. 103RD AVE. 8 CREEK RD. NO. SS -6026, VOL.25, 1 T f / I 6 •- OF :- I NO IIII 1 17 / I00000 Orr I "1 00 r I 1' I 0 �' -If I ON,-` 1 I I000 I I C'9iQ \ / 1 OFF .00 I �y II) / OpL2/,oBq�, ` I I I `ei f / \\OF I er ;�/ 150' RIPARIAN SUFFERIN \ Q .�11 � I TlllTb!;\ ill, /:> \ ! %l OFF OFF 1 00 EXISTING y>� �� ,IF IF � V` RIPARIAN �eq�'t�� OF UNIT 3 i,kA d V , e� 424soFIT I (F- o `y ' T 'Y QS / •�OF 6 /�FTq. / \ \\, � rc .11 1 Fe% OFF yOFF G IN I Of p IF Fil yIF -[ _ % EXISTING �� IV t/I -• UNIT 5N. F Q _ \ \ YV PRI RECEPTACLE PAD If IN. IF OFF, Vi _ YV PRIVACY FENCE TYPE II / / E)N - HYDROSEED TO EDSE OF G OFF v kk Y1 / / 0"TIaYT1ON D15TLRSED /r /. P/r / Rq/NqG 'Fill, AREAS. RfTFNT \ . i , , 1, t ON / / / /, /+ OF PGNG ON PGNG C` /� / ".: GKI IFIF I CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COON TY BM #596 U � CONC, MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. 8 CREEK RD. NO. SS -6026, VOL.25, ELEV.= 338.31 pG.304 (NGVD 1929) HGT. PROPOSED PLANT SCHEDULE 51ZE = CALIPER OR SPRI COT Op O I , OF \ I 'CONTRACTOR TO VERIFY OUANT1TiE5 AS SHOWN ON PLAN p0 ( " y I IRRIGATION NOTE• AN IRRIGATION SYSTEM PROVIDING FULL COVERAGE IN ALL LAWN Al t \ U � O o 4TY. SYM, SCIENTIFIC NAME COMMON NAME HGT. SIZE CONDITION REMARKS o N CW G TREES 4 B4 B5nL4 K 5NILO 5AASN' SMLO S=LAM RIV6i wl - CAL B a B OECrG / SINSLL slB 4 LK LOftVS KOUT+A MLKY INAY MLKY HAY 0 - �- B and B CEOIOVOP / SINSLC STBY 4 OR 29KU5R SLR lM SFIRP 0Wl�Cp15PIR5 OAK - ]•4L Botle gSCIgbUS/eun-nIIR4:® 10 TP nUJA RJurA•aRra c✓,Nr• r 9r6w,c®c Idly - e' -r wo EveeOrt�l/ntn-rwMKm U OFF SHRUBS O BH 9/N.9 H SRffiI BP.AlIIY M®LOAH 8016'Y000 - 4•-5' N AGOBtT/ PLAMT P.5 5Fb1W e W TxA•(AORosnS A 1UMl- F KA4 POHi9rt31 R® S.¢A45 9 SAL P9iB,'IMK / PLNlT 0 24. OL. O+ OM ORYOPI sBRILOANLS• P1fiIRIN BRIW.VIGE fHWI - ISAL f WFJIFL/FLMT•24. OL ,`.�' EOP 9'INAGG P. YLH YtlYI' PIIPHE LGH2 FLOY@I - I SN- F3tB�wAL / H -ALIT. 24. OL. - FS FC 1JGA 6. BEY &lE w im FL{� l{4 I BAL Fg!@iMAL / gJWr Ir 24' oz. ¢ Ho9 9 9^ PAY IDLY 5P. 9 SAL Pa+BUNIAI / pLAHT • 24. OL w4 N2RNGCA,r. wlcra eJ.e N.vRAA n MKKo al.�' _ 5 sa.. Accalr / asT(r Ar As anus( O fFP MSLAYTW55. AOb10 AOASIO NWo@16RAY _ I6AL ALCHIT/PLANT ATAS SIYAIR PI -f m" MISK� F. OHARF I4.Y+O FI@ - 9 SAL 5V9+SRr:$1 / FLANT Ar 90. OL. PoM M:;Lmv HR4 MMITM/ T6THLV S"nRO f' N - I SAL EY6:GR®1 / H Ar 4'-0.O O SI SRREA J ,4A610 OARFEi' S Fu5k M.SIo G44PET - I SPL EYfiP6R®1 / RANT AT 4b' O 00 VTL feel (DIY. LEAn6M1FPFN9AUIW - 740,H AGo8/T/PLANT AS SNOYH broundcover AUV MR ARGTO5TAPHYLOS UVA -URSI MAHONIA REPENS KINNIKINNICK LOW OREGON GRAPE I GAL GO O.G. • . " . % NATIVE VEGETATION WITHIN TREE PROTECTION AREA TO REMAIN �'��••t�e/, SOD LAYN AREAS SHRUB If ON IINI PROPOS® `... , , AREAS SHALL BE INCLUDED IN THIS PROJECT. _ 5 PARKINS LOT I Fell1� • - 1/ 7} `T� / r ��' 1 LISHT TYP. MAINTENANCE NOTE LANDSCAPING AND IRRIGATION SYSTEM SHALL BE PROFESSIONALLY MAINTAINED TIOFF OF p FOR THE LIFE OF THIS PROJECT ALL PLANTS SHALL SE SUARANIF FOR ONE FULL YEAR FROM '� i DATE OF ACCEPTANCE AND ALL RE7LAGEM541f RE-SUARANTEED FOR ANOTHER FULL YEAR. ORFIN I rrrrr• j QR Fee 1® ON r / l IrF I EXISTING al I riiii/iii UNIT 4 IF ' I I\\\\FINN ON Ile,�.., va ��. �..•. ... w I J. p. i rii r_NVNO I IF ��., ��. ��.. /�/a /G% so' wPAwav eu� ? PROPOIN IOF In IF SED I I I OFFAL11 /•OF IF I NO OFF �oUNIT 2 'NO ON r *I I iOF ON 1NO OF IF IF I /I OF -� F G� i,_ ; PROPOSED 7 1,o` 0 IF IF a NIT I IN OF OF OF 1 1 IF IF jOF/ , OFFf1 OFF OF ..:� / I % RIPARIAN BUFFER j. I. IF R :.. ' .: LANDSCAPOFF I RESE AT _� t " -- _d _ , ,,:, -. - ' _ - \ORE USE SPE®YVORi FOROF BYE j QR i ol so Fr 1. / _._ _ �:' 4:.. a .SRf111lD COVHi ` iii rrar,ALL Cil I IF FO Oil - / FRO.EOT LIMITS. 1IN IF - J IFFBN - /IF I I IF IN I OFF GK rM3+r / IF IN Milo ill - IN OF OF OFF. C� Z ,' I r i { effer I/ IN FIT OFFI I OF OF %ry ® I Or OF `IF IF ry zll —' `— iN IN OF IF OF v��j�•��i ` of zl, , DRAINAGE. w r a — — r EL ET Or RETENTION F OFF/ aIOF Q�� ? 0 1 PGND' kw. _ ON r IF, I FIT- % O� U�\O r IF r oOF I IF a r/irriniii riiiiiii IF 1�.—1 IF r IF PAD — �I 6 PVCI DUMPS�ER 1111 I I W ��If NI Of I _ Oil��III o� QR v �� J i NO OFI j— 1 p } Oil IF I .—IF -i.` \ REMOVE . '-y.-y IF U I1 SELECTEDy >II III ON OF I OF IF OF OF OF OF I I l �, _ 1 - � TREE(5) - r•.IF I OF IF OF -- - I IF I OF �N MAII RRXFS 1 — --IN IF DRAINAGE SWALE ON/ Feel OFF, OF OFF I OFF, j EXISTING ILI LANDSCAPE TO I IF RETAIN EXI5TING TREE5 Al � I:' I - i. VEGETATION y �• y�, p �Ny� nmg i_ REMAIN - 1200 -- - -I �. - ^ n` �t� TOP TP UTP LM rr5pia� A TOP rP � � rP C �' C4 i�OFOFF rF_FTIF�PROPERTY LINE DONALD DETTL 643034002 THIS DRAWING DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS CERTIFIED BY HATTON GODAT PANTIER. ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE REVIEWED AND APPROVED BY HATTON GODAT PANTIER. TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHICDATA SHONM ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT. a N 0 U � O o tt1 N ry F - o N CW G a' m Q m > wl m ❑ x U O K 2 Q a N 0 J W APPROVED FOR CONSTRUCTION BY: DATE: 2020.0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM AGENCY No. SHEET: 14 OF 17 EjdgrJ194=?l"351CDs INDEX APPROVAL EXPIRES: JOB: 19.035 4 a F - o N CW G a' i Q J W APPROVED FOR CONSTRUCTION BY: DATE: 2020.0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM AGENCY No. SHEET: 14 OF 17 EjdgrJ194=?l"351CDs INDEX APPROVAL EXPIRES: JOB: 19.035 YELM CREEK APARTMENTS 1651 1 CREEK ROAD, YELM, WA 98597 M9TALLATTON 5PE.LIFICA7TONB I. SCARIFY OR OTHERW15E REMOVE ALL EXI5TIN& VEGETATION FROM ALL PLANTING AREAS. FINE GRADE ALL LANDSCAPE BEDS PRIOR TO BARK OR GROUNDCOVER PLACEMENT, 2. NO PLANT WEISTITUTION5 WILL BE ACCEPTED WITHOUT PRIOR APPROVAL FROM THE LANDSCAPE ARCHITECT/OWNER AND THE CITY OF OLYMPIA. 5. ALL PLANT MATERIAL AND PLANT LOCATIONS SHALL BE APPROVED, AT THE REOUE5T OF THE LAND50AFE ARCHITECT, PRIOR TO INSTALLATION. ALL PLANT5 SHALL BE THOROUGHLY AATE RE12 IMMEDIATELY AFTER PLANTING. 4. PRIOR TO PLANT INSTALLATION, AN INSPECTION OF THE SOIL AMENDMENT AND PLANTS TD BE INSTALLED WILL BE SCHEDULED BY THE APPLICANT AND PERFORMED BY THE CITY, SOIL MIX FOR BED PREPARATION AND PLANTING BACKFILL SHALL BE A COMPOST AMENDED SOIL CONSISTING COMPOSTED STEER MANURE, BIOSOLIDS, OR MUSHROOM COMPOST, OTHER SOIL MIX PRODUCTS MUST BE APPROVED BY THE LANDSCAPE ARCHITECT PRIOR TO USE. 5. 501L PREPARATION FOR SHRUB 13E05 AND LAVA! ARE45: SPREAD TO A MINIMUM DEPTH OF 3 INCHES (4 CUBIC YARDS PER 1000 5.F) OF SOIL MIX PER NOTE 4, IN ALL GROUNDGOVER AND PLANTING BEDS, ROTOTILL OR OTHERWISE THOROUGHLY INCORPORATE SOIL MIX TO A 5-6 INCH DEPTH &RADE SMOOTH, AND REMOVE ALL ROCKS AND CLODS OVER I INCH DIAMETER FOLLOWING ACCEPTANCE OF THE W96RADE, THE LANDSCAPE CONTRACTOR SHALL PLACE AN ADDITIONAL. 6 INCH DEPTH OF COMPOST AMENDED SOIL PER NOTE 4, AND INCORPORATE (ROTOTILIU TO A DEPTH OF AT LEAST 6 INCHES. 6, BACKFILL MIX FOR ALL TREES AND SHRUBS TO E36113 EXISTING SITE TOPSOIL AND 2/3 SOIL MIX PER NOTE 4, REFER TO FLANS AND DETAILS REGARDING INSTALLATION OF PLANT MATERIALS, 7, FERTILIZER FOR ALL PLANTS SHALL BE AGRIFORM 20-10-5, 21 GRAM OR 10 GRAM TABLET5 DISTRIBUTED AS FOLLOWS: TREES 4-21 &RAM TABLETS, SHRUBS 2 GAL SIZE AND LARGER 3-21 GRAM TABLETS, I GAL SIZE SHRUBS I-21 GRAM TABLET, ALL 4" POTS I - 5 ORM TABLET OR EOUI VALENr EACH. SET TABLET5 DIRECTLY NEM TO ROOT BALL. GRANULAR EOUIVALENT FERTILIZER 15 ACCEPTABLE WITH PRIOR AUTHORIZATION FROM THE LANDSCAPE ARCHTECi, 6, TO REDUCE EROSION MINIMIZE EVAPORATION PROVIDE FOR NEED CONTROL, AND ENHANCE GROWING CONDITIONS ALL AREAS PLANTED, INCLUDING SHRUB AND GROUNDCOVER BEDS SHALL RECEIVE A FOUR (4) INCH MINIMUM DEPTH 02 CUBIC YARDS PER 1000 Si OF HEM -FIR MEDIUM BARK MULCH, PLANT 4" POT GROU1000VER5 INTO SOIL MIX PER NOTE 5 ABOVE, PLANTS PLANTED IN BARK MULCH ONLY ARE NOT ACCEPTABLE. 4. APPLY A GRANULAR OR SOLUBLE PRE -EMERGENT HERBICIDE AS APPROVED BY THE LANDSCAPE ARCHITECT TO ALL SHRUB AND GROUNDGOVER BEDS PRIOR TO DISTRIBUTION OF BARK MULCH, 10, LAWN AREAS SHALL BE SODDED WITH "PERFECT GREEN", NO NET SOD BY COUNTRY GREEN, OR APPROVED EQUAL (60% PERENNIAL RYMRA55, 20% HARD FESCUE, 20% KENTUCKY BLUE&1RA55. PLACE 5012 WITH JOINTS STAGGERED AND TIGHT, ROLL WITH WATER FILLED ROLLER FOR AN EVEN SMOOTH SURFACE, WATER 5012 AREAS IMMEDIATELY AFTER INSTALLATION. I1. FINISH GRADES FOR PLANTING BED AREAS (AFTER BARK MULCH PLACEMENT) SHALL BE I INCH BELOW ADJACENT 500 AND PAVED SURFACES. FIN15H GRADES FOR LAWN AREAS SHALL BE I INCH BELOW ADJACENT PAVED SURFACES AFTER 5012 PLACEMENT. 12. ALL LANP56APED AREAS SHALL BE PLANTED TO ACHIEVE 60% PLANT PEN51TY WITHIN 5 YEARS OF PLANTING, ADDITIONAL PLANTINGS MAY BE NECESSARY UPON INSPECTION BY THE CITY, 13. GROUND COVER SHALL BE PLANTED AND SPACED IN A TRIAN&JLAR FASHION (SEE 5PAGING DETAIL) IN A TRIANGULAR PATTERN MICH WILL RESULT IN COVERAGE OF EIGHTY (60)PERCENi IN THREE (3) YEARS. 14. ALL WORK SHALL BE PERFORMED TO THE SATISFACTION OF THE LANDSCAPE ARCHITECT/OWNER AND FINAL I1%15PEGTION APPROVAL BY THE CITY OF OLYMPIA, ALL PLANTS SHALL BE 61)ARANTEED FOR ONE FULL YEAR FROM DATE OF ACCEPTANCE. ALL REPLACEMENTS SHALL BE RE-&UARANTEED FOR ANOTHER FULL YEAR FROM DATE OF INSTALLATION, 15. THE LANDSCAPE PLAN SHALL BE UPDATED 51-fOVIING ACCURATE PLANTING MATERIALS PRIOR TO BUILDING OCCUPANCY. THIS DRAWING DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS CERTIFIED BY HATTON GODAT PANTIER. ANY ALTERATIONS TO THE DESIGN SHOWN HEREOI• MUST BE REVIEWED AND APPROVED 8Y HATTON TOTE: THE CONTRACTOR SHALL BE FULL Y RESPONSIBLE FOR THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THE CONTRACTOR SHALL VERIFY ALL UTILITY LOCATIONS PRIC TO CONSTRUCTION BY CALLING THE UNDERGROUND LOCATE I INF AT 1-800-424-5555 A MINIMUM OF 40 HOURS PRIOR TO ANY THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS BELIEVED 70 BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT I NFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT. BIODEGRADABLE TREE TIE CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSION COON TY BM #590 CONC. MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. B CREEK RD, NO. SS -00201 VOL25, ELEV.= 338.37 PG.304 (HCVD 1929) tD PASSED AROUND TRUNK FASTENED TO STAKE WITHIN 3" OF TRUNK (2) 2"X2"X6' WOOD TREE 3" SAUCER FOR WATERING SEE PLANT LIST FOR 5TAKE5 AT APPROX. 1/2 PROPER 5PAGING TO I/3 HEIGHT OF TREE - -L PEEL BACK TOP 2/3 OF BURLAP PREPARED BACKFILL MIX _ REMOVE ALL STRING AND WIRE 2/3 EX, 501L AND 1/3 SOIL MIX = SCORE ROOTBALL AND PIT WALL 2" BARK MULCH NOTE5: �I - - (4) 21 GRAM AGRIFORM f—EXI5TING GRADE FERTILIZER TABLETS 1— - I I_ =I" I. III I^ II_ REMOVE TREATED OR SYNTHETIC AMENDED __ ) SCARIFY SIDE OF BURLAP COMPLETELY. DRIVE STAKES E MIN. IV SOIL - -I - HOLE 4 ROOTBALL INTO UNDI57URBED NATIVE SOIL 111111= KEEP ROOTEIALL H015T'AND NATIVE PROTECTED PRIOR TO PLANTING MIN. 2X BALL DIA, SET ROOTBALL ON UN0I5TURBED 501L — (1) 21 ON, AGRIFORM OR 5' WHICHEVER HOLD GROWN OF ROOMALL AT I5 GREATER SU06RADE 3„ TABLET PER I GAL OR . V5T ABOVE FIN15HEP GRADE (1) 5 ON. PER 4" POT CONIFEROUS TREE PLANTING DETAIL Nor TO SCALF BIODEGRADABLE TREE TIE PASSED AROUND TRUNK FASTENED TO STAKE (2) 2"X20 X6'WOOD TREE STAKE TREE WRAP: WRAP 70 BOTTOh OF BRANCHES; TO REMAIN ONE YEAR PREPARED BACKFILL MIX 2/3 EX. 501E AND I/3 501E MIX NOTES: REMOVE TREATED OR SYNTHEI BURLAP COMPLETELY. KEEP ROOTHALL MOIST AND PROTECTED PRIOR TO PLANTIh HOLD GROWN OF ROOTBALL AT OR .NST ABOVE FINISHED GRADE MIN ]Jf &>LL DIA DR s' ItlAGF€vBR IS 6RFAT92 DECIDUOUS TREE PLANTING DETAIL Nor ro SCALE DAMAGED TWIGS PLANTING IN VERTICAL POSITION MULCH TO WITHIN 3" OF TRUNK ICER FOR NATERING OR LAWN PER PLAN GRADE 3AGK TOP 2/3 OF BURLAP ✓E ALL STRING AND WIRE ROOTBALL TRAM AGRIFORM .IZER TABLET5 STAKES A MIN. OF 12" NDISTURBED NATIVE SOIL. 70TBALL ON UNDISTURBED SUBGRADE GONTIhNOUS OUTER ROW X FEET ON CENTER 2/3 X FEET SETBACK FROM EDGE OF PLANTING BED TRIANGULAR 5PAGING INSIDE BED OF PLANTING BED Sir 91. will RAN vp EQUAL SPACING ' \--p13 OF SPACING X = REGOMMEDED PLANT SPACING (SEE PLANT SCHEDULE) ®= REPRESENTS A PLANT PLANT 5PAGING DETAIL NOi i0 SCALE LESS THAN I GAL. I GAL. CONTAINER 6 LARGER (PLANTED AFTER MULCH) (PLANTED BEFORE hNLGH) GROUNDGOVER PLANTING DETAIL NOi TO SCALE oG9 " V 2"BARK MULCH WATERING BASIN BERM �. e � PREPARED BACKFILL" FERTILIZER TABLET5, 2-6" DEPTH MIX. WATER 6 TAMP TO (3) 2 GAL OR LARGER, (1) 1 GAL REMOVE AIR POGKET5 PEEL BURLAP BACK FROM TOP 213 OF ROOT BALL AFTER PLACING NATIVE SOIL 5HRIJO IN PLANTING HOLE, REMOVE FOERGLA55 OR TREATED BURLAP COMPLETELY, NOTES: PLANTING PIT SHALL BE A MINIMUM OF TWICE THE ROOT BALL WIDTH AND TWICE THE ROOT BALL DEPTH SHRUB PLANTING DETAIL NOT TO SCALE APPROVED FOR CONSTRUCTION BY: DATE: DEVELOPMENT REVIEW ENGINEER, CITY OF YELM APPROVAL EXPIRES: AGENCY NO. 2020.0004 SHEET; 15 OF 17 EUd9 n/19-00419-035/CDs INDEX. JOB' 19.035 D tD N N m � m m o � w z $ � O U O N AGENCY NO. 2020.0004 SHEET; 15 OF 17 EUd9 n/19-00419-035/CDs INDEX. JOB' 19.035 YELM GREEK APARTMENTS 1651 1 CREEK ROAD, YELM, WA 98597 `C IF / C { Li Zee �II 11 _ y1 C>d r � I,J V - /IT' / v VIVA / TOe ReTFNT/ \ \ of Ory �7� \ pON p p% Op OF p0I IF r �. pa O. ,S 10 \ IT jpl \i \ 's, �,. ITT IT ,I iF 150' RIPARI, NI #P STRIP SPRAY INIT, Il / PLA NIIN6 ISLAI TYP. - �r / / r �. \ ---- rl \/ \ ' v _ 404 IT \ Cp ITT i Li > ( • T If H Oi r A� GO 273 DRIP r..IF 5' 5' IA° MAINLINE i 6 7 kI y ( TO ffffrT--- —�-- W, —6"PVC -- =---W-- L Tri / / DUMPSTER ��i -- PAD -V I' W I 0 I — — THIS DRAWING DOES NOT REPRESENTA RECORD i 1. ��- _ DOCUMENT, UNLESS CERTIFIED BY HATTON GODAT / - I - i' �Y �L}Q �1 PANTIER dd MUST BE REVIEWED AND APPROVED BY HATTONIER. � GODAT PANT1- MAILBOXES--� ANY ALTERATIONS TO THE DESIGN SHOWN HEREON NOTE: THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR IN BOLDING THE LOCATION AND PROTECTION OF ALL EXISTING UTILITIES. THECONTRACTORSHALLVERIFYALLUTILITYLOCATIONSPRIO TO CONSTRUCTION BY CALLING THE UNDERGROUND LO -- - -- --, PROVIDE MANUAL DRAIN AT LINE AT 1-800-424-5555 A MINIMUM OF 48 HOURS PRIOR TO ANY OP hV-0 IIE FOR NHIMM, EXCAVATION. FLUTE DISCHARGE TO SM TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS, WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT. 20 10 0 20 40 u"^u CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. & CREEK RD. NO. SS -8026, VOL.25, 1 SCALE: 1" = 20' CITY OF YELM m rn VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COON TY BM #596 CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 AT INT. 103RD AVE. & CREEK RD. NO. SS -8026, VOL.25, ELEV.= 338.31 (NGVD 1929) PG, 304 IRRIGATION PARTS 5PEGIFIGATIONS SYN. 7-IFR/PART NO. DESLRIPTiOWINSiALLAT/oN 0 Lk4MPION 20ORS-150 BRA55 MANUAL DRAIN VALVE. SEE INSTALLATION DETAIL CEIRDIIIIA INSTALL AT ALL MAINLINE LOW POINTS (NOT EII TER ICV 5FRIE5 ELECTRIC REMOTE CONTROL VALVES, INSTALLED WITH ICV -1016 N PI UNION (LATERAL SIDE) AND LVE BOX (USE COMMON BOXE5) OLVE, O CHAMPION CV-IOOVL BRASS OUICK COUPLER VASINGLE LOS WITH LOC.KIN& COVER, PROVIDE (11 KEY WITH HOSE SWIVEL. INSTALL A5 OETAILED. W SPEARS OR EOVAL HEAVY DUTY SOLVENT WELD PVL BALL VALVE FOR MAINLINE ISOLATION BEE DETAIL, SIZE PER LINE AS NOTED ON PLAN. BRAS5 BALL VALVE HAMMOND, NISCO, WILKINS BRASS BALL VALVE OR APPROVED BOVAL, Z FOR MAINLINE ISOLATION, SEE DETAIL. SIZE PER LINE AS NOTED ON PLAN. Q ® WJNTER ICZ-ICI REMOTE CONTRd- DRIP ZONE KIT r11th FILTER and PRESSURE REV.LATOR HUNTER MLO -05-12-250 MINI LANDSCAPE ORIFI_INE TI 0.4 - 0.55 SPIN EMITTERS at 12° ON CENTER SPACIN& - ALL TUBING SHALL BE INSTALLED ON &RADE BURIED UNDER BARK MACH W/ 4" WIRE STAKES THREE (3) FEET ON LETTER; VE IFY LAYOUT and ON CENTER SPACING IN THE FIELD PRIOR TO COHMENCVI OF WORK. INSTALL ON GRADE ORP IRRIGATION SYSTEM per MANIFALTI#2ER5 SPECIFICATIONS. Q RB 4S5T MFR 4xIB' SIDE STRIP NOZZLE e RB 10 H/O VAN RAINBIRD 10 SERIES NOZZLE, ISO DEG OR 40 D0155& m N ry Y m � w mo x > �j 3 v .. w qa w � a ul O U O N a � V om � N K � F M 710 O to°m� E QJy L �Om 0 d M �Z FEBOO BSW-DCV DOUBLE CHECK VALVE BACKFLOW A55ETMBLY, I INCH SIZE, INSTALL Z � F WITH (IJ 6ALVANIZC� UNION (DOWNSTREAM), AND JJN®O VALVE BOX. O Z SEE INSTALLATION DETAIL � w © Fk4I I0 -600 -PL SOLID STATE EPCTRONIC CONTROLLER NTH 1/0 PLASTIC CABINET AND X2 IRR CONTROLLER INTERNAL TRANSFORMER Q ONE OR THIO FILED COMMON MORE TERMINALS SHALL BE AVAILABLE NTHIN THE CONTROLLER CHASSIS TO BE USED IN GON.DMTION NTH STATION OUTPUT AND P/MV WIRING, PEDESTAL MOUNT AS DETAILED (ELECTRICAL CONTRACTOR TO PROVIDE 120V PRIMARY TO PEDESTAL. ROUTE CONTROL MIRE PER NE.C, (No SYMJ ESP -4V RE5&JMQ3a6rI OPERATED CONTROLLER FOR ROUNDABOUT AND LAKE FOREST ZONES F❑ FLOW SENSOR a (VO SYM) OUAL-1, MAI INSTALL I- AND 2- STATION DECODERS AND EURSE ARRESTORS AT VALVE DUAL -5 LOCATIONS. SEE VALVE CHART FOR DECODER TYPE. CONTRACTOR TO (WHERE NOTED AS -BUILT DECODER KEY FOLLONN& INSTALLATION y ON PLAN) p N_ 11114 11114 11114 11114 MAINLINES PRE59.RE MAINLINE AND LATERALS SHALL BE SDR -21 RECLAIMED WATER PIPE, 200 PSI, PVC 1120, SOLVENT MELDED. TEFLON TAPE ALL THREADED LATERALS - .fOIMT5. BURY DEPTH, MAINS=IB INCHES, LATERALS= 12 INCHES MIN. SEE NOTES BELOW FOR PIPE SEODIN6. IF SLEEVES SLEEVES SHALL BE 1/4" WALL STEEL CASING WITH A MINIMUM COVER OF 24 INCHES, SIZE PER PLAN (1 4") SEE NOTES BELOW FOR CONTROL WIRE, SLEEVE INSTALLATION. LOW VOLT CONTROL KI SHALL BE HINTER ID -N, 14 &A APO STANDARD DECODER CABLE, SINGLE TN5TED PAIR T.7 WAL LISTED. DECODER CONTROL. MIRE SHALL BE CONTINUOUS FROM CONTROLLER STATION TO END OF LINE. NO Y,^•1 IN- INE SPLICES MAY BE MADE E(CEFT AT VALVPDECODBR LOCATIONS, AND MAINLINE BRANCHES, ALL BRANCH V' SPLICES SHALL BE PERFORMED NTH 3M HEATHER PROOF CONNECTORS OR APPROVED EQUAL, AND BE LOCATED IN A ..fl STANDARD Io" ROUND VALVE BOK AND CLEARLY DENOTED ON THE AS-B/1LT ORAKN&5, SURE PROTECTED DECODERS SHALL BE INSTALLED YWERE INDICATED IN THE VALVE SCfEDU A USIN& b FT &ROUNMI ROD AND BRONZE &ROLONDIN6 CLAMPS. ^ r FL O) N co co VALVE CHART 28.4 PLOW (&FIN IM. < 2 VALVE SIZE ZONE NA43ER 'z Z 15" s W� g ZONE DECODER SIZE PLOW (61VIM1 Shrffr # DESCRIPTION -- (MAX=38) C L } ZLd At I.5" O o [� oQ 0 k RIF BUILDING B BEDS �m A2 k 15" DRIP BUILDING B BEDS )-. w BI k 15 DRIP BUILDING q BEDS 1a /� w B2 k I.5" DRIP BUILDING 4BEDS C7 Z W Y - I k I.5" 24.6 BUILDING B &BOSSED AREA W 1 `F2 k 1.5 27.5 BUILDING 4 &RA55ED AREA `�LU L VIVO It USE SURGE PROTECTION DECODER LSP) TURF AT WIRE TERMINUS W V \ { INDICATES ICD -200 OR ILD -400 2- AND 4- STATION DECODERS ix CD LATERAL LINE PIPE SIZESPECIFICATIONS: U .- DRAIN�GE 9 '� PVC LATERAL SEGMENTS SHALL BE SIZED BY CONTRACTOR OURIN& INSTALLATION SUCH THAT THE FLOW 5HALL NOT EXCEED 4 FEET PER SECOND, OR THE FOLLOWING GALLONS PER MINUTE, W GL200 SIZE MAX 6.101 �r 3/4° 1" 144 APPROVED FOR CONSTRUCTION 11/4" 22 BY: DATE AGENCY NO. 2020.0004 11/2" 26 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM 2" 45 SHEET: 16 OFA Eldgn/19-000119-03510 Ds INDEX: APPROVAL EXPIRES: JOB: 19-035 om � N K � F M 710 O to°m� E QJy L �Om 0 d M �Z FEBOO BSW-DCV DOUBLE CHECK VALVE BACKFLOW A55ETMBLY, I INCH SIZE, INSTALL Z � F WITH (IJ 6ALVANIZC� UNION (DOWNSTREAM), AND JJN®O VALVE BOX. O Z SEE INSTALLATION DETAIL � w © Fk4I I0 -600 -PL SOLID STATE EPCTRONIC CONTROLLER NTH 1/0 PLASTIC CABINET AND X2 IRR CONTROLLER INTERNAL TRANSFORMER Q ONE OR THIO FILED COMMON MORE TERMINALS SHALL BE AVAILABLE NTHIN THE CONTROLLER CHASSIS TO BE USED IN GON.DMTION NTH STATION OUTPUT AND P/MV WIRING, PEDESTAL MOUNT AS DETAILED (ELECTRICAL CONTRACTOR TO PROVIDE 120V PRIMARY TO PEDESTAL. ROUTE CONTROL MIRE PER NE.C, (No SYMJ ESP -4V RE5&JMQ3a6rI OPERATED CONTROLLER FOR ROUNDABOUT AND LAKE FOREST ZONES F❑ FLOW SENSOR a (VO SYM) OUAL-1, MAI INSTALL I- AND 2- STATION DECODERS AND EURSE ARRESTORS AT VALVE DUAL -5 LOCATIONS. SEE VALVE CHART FOR DECODER TYPE. CONTRACTOR TO (WHERE NOTED AS -BUILT DECODER KEY FOLLONN& INSTALLATION y ON PLAN) p N_ 11114 11114 11114 11114 MAINLINES PRE59.RE MAINLINE AND LATERALS SHALL BE SDR -21 RECLAIMED WATER PIPE, 200 PSI, PVC 1120, SOLVENT MELDED. TEFLON TAPE ALL THREADED LATERALS - .fOIMT5. BURY DEPTH, MAINS=IB INCHES, LATERALS= 12 INCHES MIN. SEE NOTES BELOW FOR PIPE SEODIN6. IF SLEEVES SLEEVES SHALL BE 1/4" WALL STEEL CASING WITH A MINIMUM COVER OF 24 INCHES, SIZE PER PLAN (1 4") SEE NOTES BELOW FOR CONTROL WIRE, SLEEVE INSTALLATION. LOW VOLT CONTROL KI SHALL BE HINTER ID -N, 14 &A APO STANDARD DECODER CABLE, SINGLE TN5TED PAIR T.7 WAL LISTED. DECODER CONTROL. MIRE SHALL BE CONTINUOUS FROM CONTROLLER STATION TO END OF LINE. NO Y,^•1 IN- INE SPLICES MAY BE MADE E(CEFT AT VALVPDECODBR LOCATIONS, AND MAINLINE BRANCHES, ALL BRANCH V' SPLICES SHALL BE PERFORMED NTH 3M HEATHER PROOF CONNECTORS OR APPROVED EQUAL, AND BE LOCATED IN A ..fl STANDARD Io" ROUND VALVE BOK AND CLEARLY DENOTED ON THE AS-B/1LT ORAKN&5, SURE PROTECTED DECODERS SHALL BE INSTALLED YWERE INDICATED IN THE VALVE SCfEDU A USIN& b FT &ROUNMI ROD AND BRONZE &ROLONDIN6 CLAMPS. ^ r FL O) N co co VALVE CHART 28.4 PLOW (&FIN IM. < 2 VALVE SIZE ZONE NA43ER 'z Z 15" s W� g ZONE DECODER SIZE PLOW (61VIM1 Shrffr # DESCRIPTION -- (MAX=38) C L } ZLd At I.5" O o [� oQ 0 k RIF BUILDING B BEDS �m A2 k 15" DRIP BUILDING B BEDS )-. w BI k 15 DRIP BUILDING q BEDS 1a /� w B2 k I.5" DRIP BUILDING 4BEDS C7 Z W Y - I k I.5" 24.6 BUILDING B &BOSSED AREA W 1 `F2 k 1.5 27.5 BUILDING 4 &RA55ED AREA `�LU L VIVO It USE SURGE PROTECTION DECODER LSP) TURF AT WIRE TERMINUS W V \ { INDICATES ICD -200 OR ILD -400 2- AND 4- STATION DECODERS ix CD LATERAL LINE PIPE SIZESPECIFICATIONS: U .- DRAIN�GE 9 '� PVC LATERAL SEGMENTS SHALL BE SIZED BY CONTRACTOR OURIN& INSTALLATION SUCH THAT THE FLOW 5HALL NOT EXCEED 4 FEET PER SECOND, OR THE FOLLOWING GALLONS PER MINUTE, W GL200 SIZE MAX 6.101 �r 3/4° 1" 144 APPROVED FOR CONSTRUCTION 11/4" 22 BY: DATE AGENCY NO. 2020.0004 11/2" 26 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM 2" 45 SHEET: 16 OFA Eldgn/19-000119-03510 Ds INDEX: APPROVAL EXPIRES: JOB: 19-035 YELM GREEK APARTMENTS 16511 CREEK ROAD, YELM, WA 98597 IRRIGATION IN5TALLA7I0N NOTE5 I, IRRIGATION SYSTEM SHALL BE DESIGN- WILT BY LANDSCAPE / IRRIGATION SUBCONTRACTOR. THIS PLAN SHALL OUTLINE THE IRRIGATION SYSTEM REQUIREMENTS. THE SYSTEM SHALL UTILIZE EXISTING IRRIGATION EQUIPMENT AND INSTALLATION MERE P0551BLE, EXCEPT YPiERE PLAN CALLS FOR AREA MOTH NEN ZONES. ((NEW PLANTING AREAS OR AREAS THAT WILL BE DISTURBED) 2. THIS SYSTEM 15 OE5IGNED TO BE SERVED FROM AN EXISTING CONNECTION AT 001YE5nC SERVICE LINE. CR055 CONTAMINATION PREVENTION DLYICE(5) SHALL BE INSTALLED. CONTRACTOR 15 RESPONSIWE FOR VERIFYING THE OPERATING PRESSURE AT THE POINT OF CONNECTION, 5, CONTRACTOR 15 RESPONSIBLE FOR COMPLETE OPERATING 5Y5TE740 KITH COMPLETE COVERA6E OF PLANTED AREAS. ALL LATERALS AND MAINLINES SHALL SLOPE TO DRAIN LOCATION(S) MERE INDICATED. OUTLINE SPECS FOR BIDDER DES16N. a. CHECK AND ENSURE MASTER VALVE 15 IN 6000 WORKING ORDER AT THE POINT OF CONNECTION. (IF INSTALLED) b. CONTRACTOR SHALL ENSURE BACKPLON PREVENTION DEVICES ARE IN ACCORDANCE WITH INSTALLED AND TO MEET CITY REO, TO MEET CURRENT CODE. IF NOT REPLACE TO MST CURRENT REGULATIONS. c. ENSURE THE NORKIN6 ORDER AND ENSURE THAT ANY GHECK-VALVE A55EMBLIES ARE IN NORKIN6 ORDER AND MEET OR EXCEED CURRENT CITY REGULATIONS, d. MOVE VALVES, CONTROL BOXES AND OTHER IRRIGATION ITEMS AWAY FROM NALL AND INTO LANDSCAPED AREAS YUNERE NOTED. e. CHECK ALL VALVES FOR LEAKS. F. CHECK ALL 51 VALVES FOR FUNCTIONING VALVES, HANDLES, OR KNO135 FOR DAMAGE OR OTHER POTENTIAL DEFECTS THAT MAY IMPACT FUNCTIONALITY, REPLACE AS NEEDED. g ALL REPLACEMENT PARTS MUST HAVE THE SAME SPECIFICATIONS AS THE PREVIOUS EQUIPMENT UNLE55 AUTHORIZED BY THE LANDSCAPE ARCHITECT. h. ENSURE THAT ANY VALVE 00XE5 EXISTING OR NEWLY INSTALLED HAVE THE REQUIRED GRAVEL BASE AT AND AT PROPER DEPTH. f. USE NEN WIRE RUNS TO NEW CONTROL AND VALVES NHERE 5HONN ON PLAN. THE ELECTRICAL CONNECTOR U5ED FOR ALL SPLICES, UP TO 600 VOLTS AND WITH WIRE 6AUSE5 RANGING FROM Ib TO l0 AWG, SHALL BE THE SM4 DBR/Y-b. THE CONNECTOR SHALL INCLUDE A GEL -FILLED TUBE THAT INCORPORATES A LID AND LOCKING MECHANISM. J. ADD NEW BCH. 40 PVC LATERAL LINES AND RB 10 WO VAN OR RB P55T MPR HEADS AS NEEDED. k. ADD ZONES IN AREAS P0IERE SHOWN, I. ADD DRIP ZONES AS NEEDED. m. SLON OUT ALL LINES. n. MOVE, CHECK AND ENSURE THAT W<JLL CONTROLLER IS IN NORKING ORDER OR REPLACE WITH NE'NER CONTROL BOX AS NEEDED. o. PRESSURE TEST SYSTEM BEFORE 13ACK-FILLIN6 TRENCHES WITH SOIL. 4, NO W -LINE HIRE SPLICES MILL BE ALLOYED. SUPPLY VALVE BOXES (AFETEK CARSON, OR EGVAL, 12" STANDARD OR 10" ROUND, WITH PURPLE RECLAIMED NATER LIDS) AT COMMON VALVE LOCATIONS. CONTROL NIRE5 SHALL BE BUNDLED AND TAPED TO MAIN EVERY 20 FEET, RUN WIRES IN COMMON TRENCH. USE ONLY WATERPROOF CONNECTORS AS SPECIFIED AT VALVE CONNECTIONS, 5, CONTRACTOR SHALL PROVIDE SLEEVES IN LOCATIONS SHOYW. SLEEVE DEPTH SHALL BE 10 INCHES BELOW FINISH GRADE, AND EXTEND BEYOND CURB OR ED6E OF PAVEMENT A MINIMUM OF 12 INCHES, SEE SPECS FOR SLEEVE TYPE. TAPE NDS OF SLEEVES TO BE USED FOR FUTURE PIPES, AND PROVIDE MARKER POST. 6. CONTRACTOR SHALL PROVIDE OrNER WITH A SET OF "AS -BUILT" RECORD DRAWINGS 51-101 ACTUAL LOCATIONS OF ALL 5PRINII SYSTEM EQUIPMENT, CONTRACTOR SHALL ORIENT OMER WITH COMPLETE SYSTEM OPERATION AND MAINTENANCE PROCEEDURE5. 7, CONTRACTOR SHALL 6VARANTEE IN M;nN6 ALL MATERIALS AND WORKMANSHIP FOR ONE PULL YEAR FOLLOWING FINAL ACCEPTANCE OF SYSTEM INSTALLATION, THIS DRAWING DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS CERTIFIED BY HATTON GODAT PANTIER. ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE REVIEWED AND APPROVED BY HATTON GODATPANTIER. NOTE: THE CONTRACTOR SHALL BE FULLY RESPON! THE LOCATION AND PROTECTION OF ALL EXISTING THE CONTRACTOR SHALL VERIFY ALL UTILITY LOCA TO CONSTRUCTION BY CALLING THE UNDERGROUN LINE AT 1-800-424-5555 A MINIMUM OF 48 HOURS PR THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS. WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE DRAWINGS AS A RESULT. IRRIGATION SPECIFICATIONS FOR YELM 10.55.050 Irrlgatlon system -r -hare Except For areas of undlsturbed exlsbng vegetation or low areas HIUI exlstng high loll molstvre condltfons, landscape areas shall have IMgatfon systems or be Hlthfn 75 Feet of a hose spigot. A. Choose Irrlgatlon davfces and design the Irrlgatlon system to posltfvely prevent rVnoFF or oversproy onto Impermeable hardscope under all condltlons regardless of Hlnd or possible equipment misallgnment. B. Assign separate 6tatfon/zones (hydrozone9) to areas Hlth dlsslmllar Hater or schedVing ragvirements. For example, separate zones should be designed For trees, shrvbs, Mowers, shady areas, sunny areas, drip Irrigation and sprinklers. O. Locate sprinkler heads based on a thorough evaluotln of physfcal, environmental, and hydraulic site condltlons, Including Hlnd. The design must not permit sprinklers to oversproy onto Impermeable hardscape Under any cond(Von. D. Specify drip Irrlgatfon For all zones planted In one -gallon or larger sfze. E. Specify Heather-Ywsed frrigotlon controllers (WBIG1. F. Specify check valves wherever necessary to prevent IoHHlead dralnage. (Ord. 495 § 12 (Exh. A), 2015). IRRIGATION INSTALLATION DETAIL5 2 IN. AALK FINISH GRADES � CURD OR PI (2" - 6") SPRINKLERS - AND POP-U'IMPACT SPRINKLERS (2) MARLEX BARBED f5_5 AT USE TEFLON TAPE ON ALL THREADED CONNECTIONS - 1/2" POLY nsa MINIMIZE BEND" MARLEX 40 STREET ELL NjLATERAL LINE FITTING POP UP SPRINKLER ASSEMBLY NOT TO SCALE FINISH 6RADE 1001 ROUND VALVE BOX SEE SPECS. WP SPLICE CONNECTORS FOR BRANCHING DECODER PAIR PRESSURE MAINLINE _ TWISTED PAIR CONTINUES AT MAINLINE PIPE TWISTED PAIR DECODER WIRE' INSTALL 4' DEPTH DRAIN GRAVEL SECURE LOOM WITH ZIP nE DECODER BRANCH LINE 24JVIRE 61;ZANCH LINE CONNECTION NOT TO SCALE VALVE BOT( SEE FINISH GRADE — PVC MAIM ADAPTER PRESSURE MAINLINE FITTING THREADED NIPPLE FVC UNIONS NOT TO SCALE CAP J FILL WITH SEALANT CRIMP SLEEVE USE RECOMMENDED TOOL BODY TYPICAL WIRE CONNECTION NOT TO SCALE no 2" PVC SLEEVE MAIN LINE REDUCING TEE PVC MALE ADAPTER PVC MALE ADAPTER J/4` X J" PROTECTIVE FPVC NIPPLE MANUAL DRAIN VALVE NOT TO SCALE CITY OF YELM VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COUN TY BM #596 a CONIC, MON, WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GPS 2 A INT. 103RD AVE. B CREEK RD. NO, SS -8026, VOL25, ELEV.= 338,31 PG.304 (NGVD 1829) MLKINS //215 - 3V4` OR E0.) BRASS VALVE. INSTALL AT ALL MAINLINE LOW POINTS TO FACILITATE COMPLETE MAINLINE DRAINAGE PVC NIPPLE —PVC ELBOW TAPE TO COVER OPENING FROM SOIL 4- DIA. DRAIN PIPE TO GRAVEL SUMP WITH SUFFICIENT CAPACITY TO INFILTRATE PORTION OF MAINLINE MGM. O MINI WEATHER STA 17ON AND FREEZE SENSOR OCONDUIT CLAMPS 02" PIPE OPEDESTAL CONTROLLER OPOST OR SUITABLE SURFACE OFINISHED GRADE DOTE: :OR MOST ACCURATE TEMPERATURE TENSING, ROTATE THE AWS SO THAT THE THERMOSTAT 'ORTION POINTS NORTH. FHE MWS IS DESIGNED TO MOUNT ON A 'OST OF 2" PIPE, %NY COMBINATION OF PIPE AND :ITTINGS MAY BE USED. MINI WEATHER STATION W/ FREEZE CLICK /GENERIC CONTROLLER NOT TO SCALE NOT TO SCALE ICZ-151-HUNTER OR LEGEND BY: APPROVED FOR CONSTRUCTION DEVELOPMENT REVIEW ENGINEER, CITY OF YELM U f O J a o ""YM o 0 > m Y II I II II ❑ II I I II x > w' M II II S2QQ U " U - U WI K 2 Q I I II II II II II II II 711 II II Q5 < 3 MIN. i' t z 0 s¢cnoxner NOT TO SCALE ICZ-151-HUNTER OR LEGEND BY: APPROVED FOR CONSTRUCTION DEVELOPMENT REVIEW ENGINEER, CITY OF YELM U f O J a o o 0 > m Y � ❑ ❑ x > w' M w S2QQ U " U - U WI K 2 Q ❑I OI UI ❑ w N Z N M VEM"MAtE NO NO IJJ zo QN Q K m O n N Lu l", U �m0 N Ionto E W CO " OO }3 m b 2 3 C )aZQm n { � V QJn L 20 In O p Or U) W. M ro Z w Lu J p = F I'EW w Q x D) 00 rn a w 0 Q 0 Y W w U LO (O U W a N J WINH W Z O a L9 AGENCY N0, 2020.0004 SHEET. 17 OF 1T EJdg rd 19-00071 M351C Ds INDEX JOB: 19-035 APPENDIX B -Soils Report YELM CREEK APTS -PHASE 2 07.27.2020 PAGE B-1 South Sound Geotechnical Consulting October 25, 2019 Yelm Creek Lane, LLC c/o Hatton Godat Pantier 3910 Martin Way E., Suite B Olympia, WA 98506 Attention: Pat Rants Subject: Geotechnical Engineering Report Yelm Creek Apartments Expansion Yelm, Washington SSGC Project No. 19085 South Sound Geotechnical Consulting (SSGC) has completed a geotechnical assessment for the planned expansion of the Yelm Creek Apartment complex in Yelm, Washington. Our services have been completed in general conformance with our proposal P 19089 (dated September 13, 2019) and authorized per signature of our agreement for services. Our scope of services included completion of seven test pits, one infiltration test, laboratory testing, engineering analyses, and preparation of this report. PROJECT INFORMATION Project plans include three additional two-story apartment buildings to the southeast of the existing apartment buildings. We anticipate conventional spread footings will be used for support of buildings with concrete slab -on -grade floors. Asphalt paved parking areas will be included. An existing storrnwater pond is in the extreme southeast corner of the property and serves the existing complex. Plans include expansion of the pond to accommodate the added development. SITE CONDITIONS New building locations are planned in existing lawn or open field areas. The new development area is generally level with a maximum elevation change of about 3 feet per Google Earth imagery. The existing stormwater pond in the southeast corner is on the order of 5 (+/-) feet lower than surrounding ground. SUBSURFACE CONDITIONS Subsurface conditions were characterized by completing seven test pits and one infiltration test on October 8, 2019. Test pits were advanced to depths between 5 and 11 feet below existing ground surface. Approximate locations of the explorations are shown on Figure 1, Exploration Plan. A summary description of observed subgrade conditions is provided below. Logs of the test pits are provided in Appendix A. P.O. Box 39500, Lakewood, WA 98496 (253) 973-0515 Geotechnical Engineering Report Yelm Creek Apartment Expansion Yelm, Washington SSGC Project No. 19085 October 25, 2019 SSGC Soil Conditions Fill was below the surface in all test pits except test pit TP -7 (located in existing storm pond). Fill consisted of mixed silt, sand, gravel, with variable organics, cobbles, boulders, and minor debris. It was generally in a loose to medium dense condition and extended to depths ranging from about 0.5 to 6 feet. Topsoil, with a thickness of about 1 foot, was observed below the fill in test pits TP -1 and TP -3. Native soil below the fill consisted of gravelly sand to sandy gravel with variable cobbles and trace to some silt. These soils were in an overall medium dense condition and continued to the termination depth of the test pits. They are considered to represent glacial outwash. Groundwater Conditions Groundwater was not observed in the test pits at the time of excavation. Mottling or other indicators of shallow groundwater was not observed to the base of the tests pits. However, soils appeared to be moister below a depth of about 8 feet in the test pit in the storm pond (TP -7). Yelm Creels is to the east of the site and may impact groundwater levels during the wetter seasons of the year. Geologic Setting The USDA Soil Conservation Service Soil Map of Thurston County, Washington shows two soil types on the site. McKenna gravelly silt loam is mapped along the eastern portion of the site, with Spanaway gravelly sandy loam in the western portion. McKenna soils reportedly formed in drainage ways and depressions. Spanaway soils formed in glacial outwash. Permeability is reportedly moderately rapid to very rapid in this soil with slight erosion hazard. Native soil in the test pits appear to conform to the mapped outwash (Spanaway) soil. GEOTECHNICAL DESIGN CONSIDERATIONS The planned expansion is considered feasible based on observed soil conditions in the test pits. However, substantial fill was observed in several of the test pits. Observed fill is not considered suitable for support of building foundations or floor slabs. Existing fill would have to be removed and replaced with structural fill. Alternatively, pier or pile support of foundations with structurally supported floor slabs could be considered. Native soils are suitable for support of conventional spread footing foundations, slab -on -grade floors, and conventional pavements. Native outwash soils are considered suitable for infiltration. Fill and topsoil are not considered suitable for infiltration. Groundwater was not observed to a depth of 11 feet below existing surface grade in the existing stormwater pond. We estimate the typical seasonal high groundwater levels may approach within 6 feet (+/-) of the base of the existing storm pond. This level should not adversely impact the planned expansion. Geotechnical Engineering Report Yelm Creek Apartment Expansion Yelm, Washington SSGC Project No. 19085 October 25, 2019 SSGC Recommendations presented in the following sections should be considered general and may require modifications when earthwork and grading occur. They are based upon the subsurface conditions observed in the test pits and the assumption that finish site grades will be similar to existing grades. It should be noted that subsurface conditions across the site may vary from those depicted on the exploration logs and can change with time. Therefore, proper site preparation will depend upon the weather and soil conditions encountered at the time of construction. We recommend SSGC review final plans and assess subgrade conditions at the time of construction. General Site Preparation Site grading and earthwork should include procedures to control surface water runoff. Grading the site without adequate drainage control measures may negatively impact site soils, resulting in increased export of impacted soil and import of fill materials, thereby potentially increasing the cost of the earthwork and subgrade preparation phases of the project. Site grading should include removal (stripping) of topsoil and fill encountered in building and pavement areas. Subgrades should consist of firm native soils following stripping. Fill thickness ranged from about 6 inches to 6 feet in the test pits and may be deeper in other locations. Final stripping depths can only be determined at the time of earthwork. We understand removal of all fill in pavement area may be financially infeasible. Some of the existing fill could be left in place if the owner is willing to accept the risk of reduced pavement life and added maintenance costs. We recommend at least 2 feet of existing fill is removed below the design pavement section (asphalt and base course) elevation in pavement areas. Additional over -excavation should be completed if debris or very soft soils are present following initial stripping. Separation or geotextile fabrics/grids could be considered to provide additional integrity to pavement subgrades where existing fill is left in place. General Subgrade Preparation Subgrades in building and pavement areas should consist of firm native outwash soils. We recommend exposed subgrades in building and conventional pavement areas are proofrolled using a large roller, loaded dump truck, or other mechanical equipment to assess subgrade conditions following stripping. Proofrolling efforts should result in the upper 1 foot of subgrade soils achieving a compaction level of at least 95 percent of the maximum dry density (MMD) per the ASTM D1557 test method. Wet, loose, or soft subgrades that cannot achieve this compaction level should be removed (over -excavated) and replaced with structural fill. The depth of over -excavation should be based on soil conditions at the time of construction. A representative of SSGC should be present to assess subgrade conditions during proofrolling. �l Geotechnical Engineering Report SSGC Yelm Creek Apartment Expansion Yelm, Washington 'SGC Project No. 19085 October 25, 2019 Grading and Drainage Positive drainage should be provided during construction and maintained throughout the life of the development. Surface water should not be allowed into cut/fill areas, building footprints, or pavement areas. Structural Fill Materials The suitability of soil for use as structural fill will depend on the gradation and moisture content of the soil when it is placed. Soils with higher fines content (soil fraction passing the U.S. No. 200 sieve) will become sensitive with higher moisture content. It is often difficult to achieve adequate compaction if soil moisture is outside of optimum ranges for soils that contain more than about 5 percent fines. Site Soils: Topsoil and existing fill are not considered suitable for structural fill due to organic or unknown materials). They can be used in non-structural fill or landscape areas. Native outwash soils observed are considered suitable for use as structural fill provided they can be moisture conditioned to within optimal ranges. Silt content can vary in site soils and make them moisture sensitive, requiring conditioning (drying or wetting) to obtain optimum moisture content. Optimum moisture is considered within about +/- 2 percent of the moisture content required to achieve the maximum density per the ASTM D-1557 test method. If moisture content is higher or lower than optimum, soils would need to be dried or wetted prior to placement as structural fill. Import Fill Materials: We recommend import structural fill placed during dry weather periods consist of material which meets the specifications for Gravel Borrow as described in Section 9- 03.14(1) of the 2018 Washington State Department of Transportation (WSDOT) Specifications for Road, Bridge, and Municipal Construction (Publication M 4140). Gravel Borrow should be protected from disturbance if exposed to wet conditions after placement. Dw•ing wet weather, or for backfill on wet subgrades, import soil suitable for compaction in wetter conditions should be provided. Imported fill for use in wet conditions should generally conform to specifications for Select Borrow as described in Section 9-03.14(2), or Crushed Sairfacing per Section 9-03.9(3) of the 2018 WSDOT M-41 manual, with the modification that a maximum of 5 percent by weight shall pass the U.S. No. 200 sieve for these soil types. Structural fi ll placement and compaction is weather -dependent. Delays due to inclement weather are corrunon, even when using select granular fill. We recommend site grading and earthwork be scheduled for the drier months of the year. Structural fill should not consist of frozen material. D Geotechnical Engineering Report (elm Creek Apartment Expansion (elm, Washington ;SGC Project No. 19085 October 25, 2019 Structural Fill Placement SSGC We recormnend structural fill is placed in lifts not exceeding about 10 inches in loose measure. It maybe necessary to adjust lift thickness based on site and fill conditions during placement and compaction. Finer grained soil used as structural fill and/or lighter weight compaction equipment may require significantly thinner lifts to attain required compaction levels. Coarser granular soil with lower fines contents could potentially be placed in thicker lifts if they can be adequately compacted. Structural fill should be compacted to attain the recommended levels presented in Table 1, Compaction Criteria. Table 1. Compaction Criteria Fill Per Application Compaction Criteria* Footing areas (below structures and retaining walls) 95% Upper 2 feet in pavement areas, slabs and sidewalks, and utility trenches 95% Below 2 feet in pavement areas, slabs and sidewalks, and utility trenches 92% Utility trenches or general fill in non -paved or -building areas 90% the ASTM D 1557 test method. Trench backfill within about 2 feet of utility lines should not be over -compacted to reduce the risk of damage to the line. In some instances the top of the utility line may be within 2 feet of the surface. Backfill in these circumstances should be compacted to a firm and unyielding condition. We recommend fill procedures include maintaining grades that promote drainage and do not allow pond ng of water within the fill area. The contractor should protect compacted fill subgrades from disturbance during wet weather. In the event of rain during structural fill placement, the exposed fill surface should be allowed to dry prior to placement of additional fill. Alternatively, the wet soil can be removed. We recommend consideration is given to protecting haul routes and other high traffic areas with free -draining granular fill material (i.e. sand and gravel containing less than 5 percent fines) or quarry spalls to reduce the potential for disturbance to the subgrade during inclement weather. Earthwork Procedures Conventional earthmoving equipment should be suitable for earthwork at this site. Earthwork may be difficult during periods of wet weather or if elevated soil moisture is present. Excavated site soils may not be suitable as structural fill depending on the soil moisture content and weather conditions at the time of earthwork. If soils are stockpiled and wet weather is anticipated, the stockpile should be protected with securely anchored plastic sheeting. If stockpiled soils become unusable, it may become necessary to import clean, granular soils to complete wet weather site work. Geotechnical Engineering Report Yelm Creek Apartment Expansion Yehn, Washington SSGC Project No. 19085 October 25, 2019 SSGC Wet or disturbed subgrade soils should be over -excavated to expose firm, non -yielding, non-organic soils and backfilled with compacted structural fill. We recommend the earthwork portion of this project be completed during extended periods of dry weather. If earthwork is completed during the wet season (typically late October through May) it may be necessary to take extra measures to protect subgrade soils. If earthwork takes place during freezing conditions, we recommend the exposed subgrade be allowed to thaw and be re -compacted prior to placing subsequent lifts of structural fill. Alternatively, the frozen soil N an be removed to unfrozen soil and replaced with structural fill. The contractor is responsible for designing and constructing stable, temporary excavations (such as utility trenches) to maintain stability of excavation sides and bottoms. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. Temporary excavation cuts should be sloped at inclinations of 1.5H:1V (Horizontal:Vertical) or flatter, unless the contractor can demonstrate the safety of steeper inclinations. Deeper excavations may require shoring. Permanent cut and fill slopes should be graded at inclinations of H: 1V, or flatter. A geotechnical engineer and accredited testing material laboratory should be retained during the construction phase of the project to observe earthwork operations and to perform necessary tests and observations during subgrade preparation, placement and compaction of structural fill, and backfilling of excavations. Foundations Foundations can be placed on native outwash soils or on a zone of structural fill above prepared native subgrades as described in this report. The following recommendations are for conventional spread footing foundations: Bearing Ca�acity�net allowable): 2,500 pounds per square foot (psf) for footings supported firm native outwash or structural fill over native subgrades prepared as described in this report. Footing Width (Minimum): 18 inches (Strip) 24 inches (Colunui) Embedment Depth (Minimum): 18 inches (Exterior) 12 inches (Interior) Settlement: Total: < 1 inch Differential: < 1/2 inch (over 30 feet) Allowable Lateral Passive Resistance: 325 psf/ft" (below 18 inches) G7 Geotechnical Engineering Report (elm Creek Apartment Expansion (elm, Washington SSGC Project No. 19085 October 25, 2019 Allowable Coefficient of Friction: 0.40# *These values include a factor of safety of approximately 1. 5. SSGC The net allowable bearing pressures presented above may be increased by one-third to resist transient, dynamic loads such as wind or seismic forces. Lateral resistance to footings should be ignored in the upper 12 -inches from exterior finish grade. Foundation Construction Considerations All foundation subgrades should be free of water and loose soil prior to placing concrete, and should be prepared as recommended in this report. Concrete should be placed soon after excavating and compaction to reduce disturbance to bearing soils. Should soils at foundation level become excessively dry, disturbed, saturated, or frozen, the affected soil should be removed prior to placing concrete. We recommend SSGC observe all foundation subgrades prior to placement of concrete. Foundation Drainage Ground surface adjacent foundations should be sloped away from buildings. We recommend footing drains are installed around perimeter footings placed on structural fill. Footing drains are not considered necessary for footings founded directly on native outwash soils. Footing drains should include a minimum 4 -inch diameter perforated rigid plastic or metal drain line installed at the base of the footing. The perforated drain lines should be connected to a tight line pipe that discharges to an approved storm drain receptor. The drain line should be surrounded by a zone of clean, free -draining granular material having less than 5 percent passing the No. 200 sieve or meeting the requirements of section 9-03.12(2) "Gravel Backfill for Walls" in the 2018 WSDOT (M41-10) manual. The free -draining aggregate zone should be at least 12 inches wide and wrapped in filter fabric. The granular fill should extend to within 6 inches of final grade where it should be capped with compacted fill containing sufficient fines to reduce infiltration of surface water into the footing drains. Alternately, the ground surface can be paved with asphalt or concrete. Cleanouts are recommended for maintenance of the drain system. On -Grade Floor Slabs On -grade floor slabs should be placed on native soils or structural fill prepared as described in this report. We recotrunend a modulus subgrade reaction of 200 pounds per square inch per inch (psi/in) for native soil or compacted granular structural fill over native soil. We recommmend a capillary break is provided between the prepared subgrade and bottom of slab. Capillary break material should be a minimum of 4 inches thick and consist of compacted clean, raining, well well graded course sand and gravel. The capillary break material should contain less than 5 percent fines, based on that soil fraction passing the U.S. No. 4 sieve. Alternatively, a clean angular gravel such as No. 7 aggregate per Section 9-03.1(4) C of the 2018 WSDOT (M41-10) manual could be used for this purpose. fl7 Geotechnical Engineering Report Yelm Creek Apartment Expansion Yelm, Washington SSGC Project No. 19085 October 25, 2019 SSGC We reconunend positive separations and/or isolation joints are provided between slabs and foundations, and colunnls or utility lines to allow independent movement where needed. Backfill in interior trenches beneath slabs should be compacted in accordance with recommendations presented in this report. A vapor retarder should be considered beneath concrete slabs that will be covered with moisture sensitive or impervious coverings (such as tile, wood, etc.), or when the slab will support equipment or stored materials sensitive to moisture. We recommend the slab designer refer to ACI 302 and/or ACI 360 for procedures and limitations regarding the use and placement of vapor retarders. Seismic Considerations Seismic parameters and values in Table 2 are recommended based on the 2015 International Building Code (IBC). Table 2. Seismic Parameters PARAMETER 'Note: In general accordance with the 2015 Inter»ational Building Code, Section 1613.3.2 for risk categories I,II,III . IBC Site Class is based on the estimated characteristics of the upper 100 feet of the subsurface profi VALUE 2015 International Building Code (IBC) Site Classification' D SS Spectral Acceleration for a Short Period 1.244 S, Spectral Acceleration for a I -Second Period 0.495g Fa Site Coefficient for a Short Period 1.002 FvSite Coefficient for a I -Second Period 1.515 le. SS, S1, Fa, and F„ values based on the OSBPD Seismic Design Maps website using referenced site latitude and Liquefaction Soil liquefaction is a condition where loose, typically granular soils located below the groundwater surface lose strength during ground shaking, and is often associated with earthquakes. The risk of liquefaction at this site is low for the design level earthquake based on the Thurston County Liquefaction Hazard Map, dated April 2011. A site-specific liquefaction analyses was not part of our scope and would be required to fully assess liquefaction potential and impacts. Infiltration Characteristics Expansion of the existing stormwater pond in the southeast portion of the site is planned to control stormwater fiotn the additional development. An assessment of infiltration potential in the expanded pond area was completed per Volume 3, Appendix III -A, Method 3 of the 2016 Thurston County Drainage 0 Geotechnical Engineering Report (elm Creek Apartment Expansion (elm, Washington SSGC Project No. 19085 October 25, 2019 SSGC Design and Erosion Control Manual. Gradation correlations based on Massmanrr's equation were completed on a sample of the native outwash from test pit TP -6 near the elevation of the base of the existing pond. Results of the correlations are presented in Table 3. Table 3. Infiltration Rates *Correction Factors from Corrected Calculated Infiltration Correction Sample ID and Soil Type Rate Infiltration Factors* Depth (ft) (in/hr) ate (Fg/Ft/Fp) (R) TP -6, S-2, 8 ft Outwash 72 23 (1/0.4/0.8) the 2016 Thurston County Drainage Design and Erosion Control Manual. The calculated and corrected infiltration rate is considered appropriate for the soil tested and is similar to infiltration tests completed at other sites with similar (Spanaway) soil throughout Thurston County. We recommend a long-term design rate of 23 inches per hour (in/hr) for design of infiltration facilities located in outwash soils. Infiltration facilities should not be located in areas where fill is present. Modifications to the above correction factors (or other factors) should be applied to the above recommended long-term rate, as required by the County manual for the type of infiltration system used. One infiltration test was completed per Simple Method 1 (modified EPA falling head procedure) o#the Thurston County Manual in the existing storm Swale between two of the existing apartment buildings. This site is referenced as IT4 on Figure 1 — Exploration Plan. The test was completed at a depth of about 6 inches below the existing bottom of swale surface. Soils consisted of silty sand with some gravel and organics. A field infiltration rate of 6.25 in/hr was assessed at the test location. Groundwater was not observed in the test pits to a maximum depth of 11 feet. Mottling or other indicators of elevated groundwater were not observed. We estimate the typical seasonal high groundwater level will be on the order of 5 (+) feet below the bottom of the existing stormwater pond in the southeast corner of the site. Infiltration facilities should not be adversely influenced by groundwater or other impervious soil layers. Cation Exchange Capacity (CEC) and organic content tests were completed on a sample of the outwash soil near the anticipated planned bottom of the expanded pond area. Test results are summarized in the table below. D Geotechnical Engineering Report Yelm Creek Apartment Expansion Yelm, Washington SSGC Project No. 19085 October 25, 2019 Table 4. CEC and Organic Content Results SSGC Test Site, Sample Number, Depth CEC Results (milliequivalents) CEC Required* (milliequivalents) Organic Content Results (%) Organic Content Required* (%) TP -65 S41 6 ft 10.5 > 5 2.41 >1.0 *Values from the 2016 Thurston County Drainage Design and Erosion Control Manual. Organic content and CEC results of the sample satisfy County requirements. Conventional Pavement Sections Subgrades for conventional pavements should be prepared as described in the "Subgrade Preparation" and "Structural Fill" sections of this report. Subgrades below pavement sections should be graded or crowned to promote drainage and not allow for ponding of water beneath the section. If drainage is not provided and ponding occurs, subgrade soils could become saturated, lose strength, and result in premature distress or failure of the section. In addition, the pavement surfacing should also be graded to promote drainage and reduce the potential for ponding of water on the pavement surface. We recommend a separation fabric (such as Mirafi 140N) is placed above pavement subgrades consisting of existing fill. The purpose of the fabric is to provide segregation between new structural fill and the existing fill subgrade. Without the fabric, the new granular fill will have the tendency to migrate into the lower fill over time, which can compromise the structural integrity of the structural fill zone leading to premature distress of the pavement. Other geotextile fabrics or grids could also be considered to improve existing fill subgrades. The fabric is not necessary where pavement subgrades consist of native outwash. Pavement section designs have been prepared and are based on AASHTO design guidelines and the following assumed design parameters: • 20 -year life span; • Estimated design life Equivalent Single Axle Loads (18 kips) of 28,000; • Estimated subgrade CBR of 15; • Terminal serviceability of 2.0; and, • Level of reliability 85 percent. recommended Minimum pavement sections for conventional asphalt or concrete pavements are presented in Table 5. We should be notified if actual traffic (ESAL) loads will be greater than those assumed to verify or modify the pavement sections. f[�l Geotechnical Engineering Report (elm Creek Apartment Expansion (elm, Washington SSGC Project No. 19085 October 25, 2019 Table 5. Preliminary Pavement Sections Minimum Recommended Pavement Section Thickness SSGC Traffic Area Asphalt Portland Aggregate Subbase Concrete Cement Base s Surface' Concrete Course 3,4 Aggregate Car Parking Areas 2 - 4 12 Main Access Routes 3 - 6 12 � 1/2 —inch nominal aggregate hot -mix asphalt (HMA) per WSDOT 9-03.8(1) z A 28 day minimum compressive strength of 4,000 psi and an allowable flexural strength of at least 250 psi s Crushed Surfacing Base Course per WSDOT 9-03.9(3) 4Although not required for structural support under concrete pavements, a minimum four -inch thick base course layer is recommended to help reduce potentials for slab curl, shrinkage cracking, and subgrade "pumping" through joints 5 Native granular soils compacted to 95% of the ASTM D1557 test method, or Gravel Borrow per WSDOT 9-03.14(1) or Crushed Surfacing Base Course WSDOT 9-03.9(3) 1/2 —inch nominal aggregate hot -mix asphalt (HMA) per WSDOT 9-03.8(1) Conventional Pavement Maintenance The performance and lifespan of pavements can be significantly impacted by future maintenance. The above pavement sections represent minimum recommended thicknesses and, as such, periodic maintenance should be completed. Proper maintenance will slow the rate of pavement deterioration, and will improve pavement performance and life. Preventive maintenance consists of both localized maintenance (crack and joint sealing and patching) and global maintenance (surface sealing). Added maintenance measures and reduced pavement life should be anticipated over the lifetime of pavements if any existing fill or topsoil is left in-place beneath pavement sections. REPORT CONDITIONS This report has been prepared for the exclusive use of Yelm Creek Lane, LLC and their agents for specific application to the project discussed, and has been prepared in accordance with generally accepted geotechnical engineering practices in the area. No warranties, either express or implied, are intended or made. The analysis and recommendations presented in this report are based on observed soil conditions and test results at the indicated locations, and from other geologic information discussed. This report does not reflect variations that may occur across the site, or due to the modifying effects of construction, or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. This report was prepared for the planned ty pe of development of the site as discussed herein. It is not valid for third party entities or alternate types of development on the site without the express written consent of SSGC. If development plans change we should be notified to review those changes and modify our recommendations as necessary. 11 Geotechnical Engineering Report Yelm Creek Apartment Expansion Yelm, Washington SSGC Project No. 19085 October 25, 2019 SSGC The scope of services for this project does not include any environmental or biological assessment of the site including identification or prevention of pollutants, hazardous materials, or conditions. Other studies should be completed if the owner is concernedabout the potential for contamination or pollution. We appreciate the opportunity to work with you on this project. Please contact us if additional information is required or we can be of further assistance. Respectfu I ly, South Sound Geotechnical Consulting Timothy H. Roberts, P.E. Member/Geotechnical Engineer Attachments: Figure 1 —Exploration Plan Appendix A —Field Exploration Procedures and Test Pit Logs Appendix B —Laboratory Testing and Results Unified Soil Classification System cc: Hatton Godat Pantier — Mr. Chris Aldrich 12 N �> <= , JOE , I RE ED ,r'S '' fI RErom�u5r eoma�r tl numra.unmerr olidre V3 4 J Y riaNo l `I` IT -1x 4 pIF „ +' 5 +. TPIfFIFFORI,-2 ❑' ti 1�5>• ' rt 1A , P EFo- s. �.5 x��',{ I SR NrMMM ' ' '.!do ' pod 'FIN 1IF�3, l'. ,'�'�' 40 RE'W243TORYa UNRB +�{ �r�x '� r 4 tr T.'"i. y rr TP 1 WJE.O IF .o® t _ Y `�"""m TP -4 A — meIF IFF I IS Lid —u ..�... iaW TP -1 JM Approximate Test Pit Location IT -1 ❑ Approximate Infiltration Test Location No Scale pb IF r wq , su terra gra mm� �vwxva, ple.e.,r.,..a .o dna IFMr 91 c TP -3 OFrIF I IF I tcra0m 1 r�wv� IFu NEW ss ' h,ti :-sTORr ® TP -7 a UNITE Le d IF IR IF arfM.BOflra t@• �laYN rwlaw�slw nmr�waaro�ly. ' Base map drawing "Yelm Creek Apartment Expansion, Preliminary Site Plan, by Hatton Godat Pantier (June 2019) Figure 1 —Exploration Plan Yelm Creek Aparhnent Expansion Yelm, WA SSGC Project #19085 Geotechnical Engineering Report Liberty Lease Olympia, Washington SSGC Project No. 19067 August 8, 2019 Appendix A Field Exploration Procedures and Test Pit Logs SSGC Geotechnical Engineering Report SSGC Yelm Creek Apartment Expansion Yelm, Washington 'SGC Project No. 19085 October 25, 2019 Field Exploration Procedures Our field exploration for this project included seven test pits and one infiltration test completed on October 8, 2019. The approximate locations of the explorations are shown on Figure 1, Exploration Plan. Test pit locations were determined by pacing from site features. Ground surface elevations referenced on the logs were inferred from Google Earth satellite imagery. Test pit locations and elevations should be considered accurate only to the degree implied by the means and methods used. A private excavation contractor subcontracted to SSGU dug the test pits. Soil samples were collected and stored in moisture tight containers for further assessment and laboratory testing. Explorations were backfilled with excavated soils and tamped when completed. Please note backfill in the explorations may settle with time. Backfill material located in roads or building areas should be re -excavated and recompacted, or replaced with structural fill. The following logs indicate the observed lithology of soils and other materials observed in the explorations at the time of excavation. Where a soil contact was observed to be gradational, our log indicates the average contact depth. Our logs also indicate the approximate depth to groundwater (where observed at the time of excavation), along with sample numbers and approximate sample depths. Soil descriptions on the logs are based on the Unified Soil Classification System. A-1 Project: Yelm Creels Apartments SSGC Job # 19085 TEST PIT LOGS PAGE 1 OF 3 Location: Yelm, WA Test Pit TP -1 Depth(feet) Material Description 0 — 0.5 Fill: Silt, sand, gravel, with some organics: Medium dense, moist, dark brown. Topsoil 1.5 — 3.5 Gravelly SAND with cobbles and trace to some silt: Medium dense, moist, golden brown. (Glacial Outwash) 3.5 — 6 Sandy GRAVEL with cobbles and trace to solve silt: Medium dense, moist, brownish gray. (Glacial Outwash) Test pit completed at approximately 6 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 345 feet Test Pit TP -2 Depth (feet) Material Description 0 — 6 Fill: Silt, sand, gravel, boulders, with some plastic and organics: Loose, moist, dark brown. 6 — 8 Gravelly SAND with cobbles and trace to some silt: Medium dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 8 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 345 feet Test Pit TP -3 Depth (feet) Material Description 0 —4 Fill: Silt, sand, gravel, boulders, with some plastic and organics: Loose, moist, dark brown. 4-5 Topsoil 5 - 7 Gravelly SAND with cobbles and trace to solve silt: MediLun dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 7 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 345 feet TEST PIT LOGS FIGURE A-1 South Sound Geotechnical Consulting I TPwI TO TP -7 Logged by: THR Project: Yelm Creek Apartments SSGC Job # 19085 TEST PIT LOGS PAGE 2 OF 3 Location: Yelm, WA Test Pit 1P-4 Depth (feet) Material Description 0 — 3.5 Fill: Silt, sand, gravel, boulders, with some plastic and organics: Loose, moist, dark brown. 3.5 — 6 Gravelly SAND with cobbles and trace to some silt: Medium dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 6 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 345 feet Test Pit TP -5 Depth (feet) Material Description 0 — 2.5 Fill: Silt, sand, gravel, boulders, with some plastic and organics: Loose, moist, dark brown. 2.5 - 5 Gravelly SAND with cobbles and trace to some silt: Medium dense, moist, golden brown. (Glacial Outwash) Test pit completed at approximately 5 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 343 feet Test Pit TP -6 Depth (feet) Material Description 0 —4 Fill: Silt, sand, gravel, boulders, with some plastic and organics: Loose, moist, dark brown. 4 — 9 Gravelly SAND with cobbles and trace to some silt: Medium dense, moist, golden brown. (Glacial Outwash)(Sample S-1 @ 6 feet; Sample S-2 @ 8 feet) Test pit completed at approximately 9 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 345 feet South Sound Geotechnical Consulting TEST PIT LOGS TP -1 TO TP -7 FIGURE A-1 Logged by: THR Project: Yelm Creek Apartments SSGC Job # 19085 TEST PIT LOGS PAGE 3 OF 3 Location: Yelm. WA Test Pit TP -7 (Existing SE Pond) Depth (feet) Material Description 3" topsoil over Gravelly SAND/Sandy GRAVEL with cobbles and trace to some silt: Medium dense, moist, brownish gray. (Glacial Outwash) Test pit completed at approximately 11 feet on 10/8/19. Groundwater not observed at time of excavation. Approximate elevation: 340 feet South Sound Geotechnical Consulting TEST PIT LOGS TP -1 TO TP -7 FIGURE A-1 Logged by: THR Geotechnical Engineering Report (elm Creek Apartment Expansion Yelm, Washington ;SGC Project No. 19085 October 25, 2019 Appendix B Laboratory Testing and Results SSGC Geotechnical Engineering Report SSGC Yelm Creek Apartment Expansion (elm, Washington SSGC Project No. 19085 October 25, 2019 Laboratory Testing Select soil samples were tested for organic content and cation exchange capacity (CEC) by Northwest Agricultural Consultants of Kennewick, Washington. Grain size (gradation) tests were completed by Construction Testing Laboratories (CTL) of Puyallup, Washington. Results of the laboratory testing are included in this appendix. B-1 �Ic 100 90 80 70 !Y W 60 Z LL Z 50 W U tY W 40 a 30 20 10 0 Particle Size Distribution Report ASTM 16-117,C136 % +3" %Gravel Coarse Fine 0 1 17 1 45 Coarse 10 SIEVE SIZE w PERCENT FINER SPEC.'' PERCENT PASS? (X=NO) 211 100 111 93 3/4" 83 1/211 65 3/811 57 #4 38 #8 30 #16 24 #30 16 #50 10 #100 8 #200 5.4 (no specification provided) Source of Sample: TP -6 Sample Number: 19-1512 Construction Testing Laboratories 400 Valley Ave. NE, Suite #102 Puyallup WA, 98372 Tel. (253) 383-8778 VI\/IIIV VILL - Sand Medium 15 Fines Fine Silt 8 5 Material Description Grab Sample, S-2 Sampled at 8' PL= USCS= Report: #01 Satnpled by: Client Atterberg Limits LL= P1= Classification AASHTO= Remarks Client: South Sound Geotechnical Project: Yehn Creek Aparhnents (19085) Tested By: R Rowden Checked By: C Pedersen Date: 10-08-19 6 Northwest Agricultural 46 Consultants 2545 W Falls Avenue Kennewick, WA 99336 509.783.7450 www,nwag.com lab@nwag.com PAP -Accredited South Sound Geotechnical Consulting PO Box 39500 Lakewood, WA 98496 Report: 49786-1 Date: October 11, 2019 Project No: 19085 Project Name: Yelm Creek Sample ID Organic Matter Cation Exchange Capacity TP -61 S-1 @ 6.0' 2.41% 10.5 meq/1008 Method ASTM D2974 EPA 9081 UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests" Soil Classification Group Symbol Group NameB Coarse Grained Soils Gravels Clean Gravels Cu >_ 4 and 1 s Cc!g 3E GW Well -graded gravel, More than 50% retained More than 50% of coarse Less than 5% fines' Cu < 4 and/or 1 > Cc > 3B GP Poorly fraction retained on y graded gravelF on No. 200 sieve No. 4 sieve Gravels with Fines Fines classify as ML or MH GM Silly gravel FIG•" More than 12%fines° ttttitttt Fines classify as CL or CH GC Clayey y y gravelF°p" Sands Clean Sands Cu >! 6 and 1 < Cc < 31 SW Well -graded sand' 50% or more of coarse Less than 5% fines' Cu < 6 and/or 1 > Cc > 3E SP Poorly fraction passes y graded sand' No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sandBp"' More than 12% fines° Fines Classify as CL or CH SC Clayey sand°1'141 Fine -Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A" line' CL Lean clay"pLil 50% or more passes the Liquid limit less than 50 PI < 4 or No. 200 sieve plots below "A" line' ML SiltKPL,M organic Liquid limit - oven dried < 0.75 OL Organic clay""M,N Liquid limit - not dried Organic siltK•L,M,° Silts and Clays inorganic PI plots on or above "A" line CH Fat clayKL�M Liquid limit 50 or more PI plots below "A" line MH Elastic Silt",LIM organic Liquid limit - oven dried < 0.75 OH Organic clay"•L•" Liquid limit - not dried Organic sillKL,M.o Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat °'Based on the material passing the 3 -in. (75 -mm) sieve a If Feld sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. °Gravels with 5 to 12% fines require dual symbols: GW -GM well -graded gravel with silt, GW -GC well -graded gravel with clay, GP -GM poorly graded gravel with silt, GP -GC poorly graded gravel with clay. °Sands with 5 to 12% fines require dual symbols: SW -SM well -graded sand with silt, SW -SC well -graded sand with clay, SP -SM poorly graded sand with silt, SP -SC poorly graded sand with clay z ECU = Dao/Dto Cc = Dao Dio x Dao F If soil contains >_ 15% sand, add "with sand" to group name. GIf fines classify as CL -ML, use dual symbol GC -GM, or SC -SM. For classlilcetlon of fine-grained soils and fine-grained fraction 50 of coarse-grained soils I Equation of "A" - line a Horizontal at PI=4 to LL=25.5. X 40 then PI=0.73 (LL -20) 0 Equation of "U" -line ? Vertical at LL=16 to PI=7, 30 - then PI=0.9 -+�= v I 0 a 2010 ire CL ML Hlf fines are organic, add "with organic fines" to group name. If soil contains >_ 15% gravel, add 'With gravel" to group name. If Atterberg limits plot in shaded area, soil is a CL -ML, silty clay. Klf soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel," whichever is predominant. If soil contains >_ 30% plus No. 200 predominantly sand, add "sandy" to group name. M If soil contains >_ 30% plus No. 200, predominantly gravel, add "gravelly" to group name. 4 and plots on or above "A" line. ° PI < 4 or plots below "A" line. PPI plots on or above "A" line. ° PI plots below "A" line. a VS,'--- a� -f 0XX 7 -- 4 � I ML or OL o--- L__ _. _..j _ __ -_- 0 10 16 20 30 40 50 60 MH or OH 70 80 90 100 110 LIQUID LIMIT (LL) USDA United States A product of the National Department of Cooperative Soil Survey, Agriculture a joint effort of the United NRCSStates Department of Agriculture and other Federal agencies, State Natural agencies including the Resources Agricultural Experiment Conservation Stations, and local Service participants Custom soil Resource Report for Thurston County Area, Washington July 6, 2020 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/ portal/nres/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.se.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface.................................................................................................................... 2 How Soil Surveys Are Made...... Imam MEMONDE MENEWV1080M soon mood EM588AMMEME MENEWWWO no@@ 5 SoilMap.................................................................................................................. 8 SoilMap. 0 0 0 V 0 0 T 0 V V & M 0 0 M 0 0 0 0 0 0 0 0 0 0 658899ORME M M M M I M M M M 0 a a w 0 0 0 M 8 0 0 M M 0 0 MOSTEME mold 8MEM Memnon 0 w 0 0 0 V 0 0 a 0 0 0 0 a 0 a 0 0 w 0 0 0 a 0 0 8 & M M M M 9 Legend... 9 a 0 0 0 1 0 0 0 w & a 0 0 0 6 M 0 M M 0 M M M M 0 V V 0 0 0 0 a 00 8 0 M 0 M 0 0 M M M M V M M M 0 1 e a P 0 0 2 0 0 0 0 M 0 V a 0 0 0 0 a a 0 1 1 M M a a 2 a M M V M M V V 0 a M 8 0 0 0 0 0 0 0 0 0 0 a 0 0 0 0 0 a 1 0 MapUnit Legend................................................................................................ 11 MapUnit Descriptions.........................................................................................11 Thurston County Area, Washington................................................................13 65—McKenna gravelly silt loam, 0 to 5 percent slopes... a 0 0 s 0 0 0 0 0 0 0 w w V 9 0 8 s 2 s 0 s M 0 0 0 0 0 13 110—Spanaway gravelly sandy loam, 0 to 3 percent slopes................ 14 References............................................................................................................16 now soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil -vegetation -landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 Custom Soil Resource Report scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil -landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil -landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field -observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 7 oil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 0 r 40;x. r S6 CAL im m F t� 3 MAP LEGEND Area of Interest (AOI) Area of lnterest(AQI) Soils Q Soil Map Unit Polygons .y Soll Map Unit Lines � Sall Map Unit Points Custom Soil Resource Report � Is from USDA-NRCS as This product generated the certified data Special Point Features U Blowout ® Borrow Pit X Clay Spot 0 Closed Depression x Gravel Pit e, Gravelly Spot 0 Landfill ri Lava Flow Enlargement of maps beyond the scale of mapping can cause Marshorswamp ri Mine or Quarry misunderstanding of the detail of mapping and accuracy of soil Miscellaneous Water Special Line Features Perennial Water line placement. The maps do not show the small areas of Rock Outcrop + Saline Spot contrasting soils that could have been shown at a more detailed Sandy Spot Scale. Severely Eroded Spot ;. Sinkhole Slide or Slip Please rely on the bar scale on each map sheet for map Sodlc Spot Custom Soil Resource Report � Is from USDA-NRCS as This product generated the certified data Spoil Area The soil surveys that comprise your AOI were mapped al 1:24,000. ® Stony Spot Very stony spot Warning: Soil Map may not be valid at this scale. Wet Spot Enlargement of maps beyond the scale of mapping can cause Other misunderstanding of the detail of mapping and accuracy of soil Special Line Features line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed Water Features Scale. Streams and Canals Transportation Please rely on the bar scale on each map sheet for map 1-14 Rails measurements. %10Interstate Highways Source of Map: Natural Resources Conservation Service ,y US Routes Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Major Roads Local Roads Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts Background distance and area. A projection that preserves area, such as the ■ Aerial Photography Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. 10 of the version dales) listed below. Soil Survey Area: Thurston County Area, Washington Survey Area Data: Version 14, Jun 4, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Dates) aerial images were photographed: Mar 29, 2016—Oct 10, 2016 The orlhopholo or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report Map Unit Legend Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into a" 11110 or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, 11 Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 65 McKenna gravelly silt loam, 0 to 5 percent slopes 3.6 50.2% 110 Spanaway gravelly sandy loam, 0 to 3 percent slopes 3.6 49.8% Totals for Area of Interest 7.2 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into a" 11110 or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, 11 Custom Soil Resource Report onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha -Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 12 Custom Soil Resource Report Thurston County Area, Washington 65—McKenna gravelly silt loam, 0 to 5 percent slopes Map Unit Setting National map unit symbol: 2nd9g Elevation: 50 to 500 feet Mean annual precipitation: 30 to 60 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 150 to 180 days Farmland classification: Prime farmland if drained Map Unit Composition Mckenna and similar soils: 85 percent Minor components: 8 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Mckenna Setting Landform: Depressions, drainageways Parent material: Glacial drift Typical profile H1 - 0 to 9 inches: gravelly silt loam H2 - 9 to 13 inches: gravelly silt loam H3 - 13 to 36 inches: very gravelly loam H4 - 36 to 40 inches: very gravelly loam Properties and qualities Slope: 0 to 5 percent Depth to restrictive feature: 20 to 40 inches to densic material Natural drainage class: Poorly drained Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table: About 0 inches Frequency of flooding: None Frequency of ponding: Frequent Available water storage in profile: Low (about 5.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 6w Hydrologic Soil Group: D Forage suitability group: Wet Soils (G002XS101 WA) Hydric soil rating: Yes Minor Components Norma Percent of map unit: 3 percent Landform: Depressions Hydric soil rating: Yes Bellingham Percent of map unit: 3 percent 13 Custom Soil Resource Report Landform: Depressions Hydric soil rating: Yes Skipopa Percent of map unit: 2 percent Hydric soil rating: No 110—Spanaway gravelly sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2ndb6 Elevation: 330 to 1,310 feet Mean annual precipitation: 35 to 65 inches Mean annual air temperature: 50 degrees F Frost -free period: 150 to 200 days Farmland classification: Prime farmland if irrigated Map Unit Composition Spanaway and similar soils: 100 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Spanaway Setting Landform: Terraces, outwash plains Parent material: Volcanic ash over gravelly outwash Typical profile H1 - 0 to 15 inches: gravelly sandy loam H2 - 15 to 20 inches: very gravelly loam H3 - 20 to 60 inches: extremely gravelly sand Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat) High in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.8 inches) Interpretive groups Land capability classification (irrigated): 3s Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Forage suitability group: Droughty Soils (G002XS401 WA) Hydric soil rating: No 14 (1.98 to 5.95 Custom Soil Resource Report 15 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995, Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nresl42p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www. nres. usda.gov/wps/portal/n res/detail/national/soils/?cid=nres 142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual, http://www,nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nres 142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook, http://www.nres.usda.gov/wps/portal/nres/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 16 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. http://www.nres.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nres.usda.gov/lnternet/FSE_DOCUMENTS/nres142p2_052290.pdf 17 APPENDIX C -Hydraulic Analysis YELM CREEK APTS -PHASE 2 07.27.2020 PAGE C-1 YELM CREEK APARTMENTS PHASE 2 SURFACE SUMMARY Offsite Offsite Onsite Onsite Off Site On Site Impervious Permeable Impervious Permeable Impervious Permeable Onsite Offsite Total Onsite Offsite Total Total Total Roof Road Road Total Road Parking Parking Total Parking Sidewalk Sidewalk Sidewalk Sidewalk Total Sidewalk Onsite Native Offsite Native Total Native Pond Lawn Lawn Lawn Basin Description Area (so Area (so Area (so Area (ac) Roofs Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so Area (so 1 Disturbed 45284 0 45284 1.04 2 8040 0 0 0 2882 14979 17861 0 0 1053 0 1053 0 0 0 0 18330 0 18330 2 Undisturbed 86315 0 86315 1.98 0 0 0 0 0 0 0 0 0 0 0 0 0 86315 0 86315 0 0 0 0 3 Offsite 0 16941 16941 0.39 0 0 0 0 0 16941 0 16941 0 0 0 0 0 0 0 0 0 0 0 0 Total TDA 131599 16941 148540 3.41 2 8040 0 0 0 19823 14979 34802 0 0 1053 0 1053 86315 0 86315 0 18330 0 18330 BASIN 1 WWHM INPUT BASIN 2 WWHM INPUT BASIN 3 WWHM INPUT Roof Areas SF AC Assumed Impervious Geodata Ac PredevelopE Mitigated Predeveloped Mitigated Predeveloped Mitigated BUILDING 6 4020 0.09 Hard Surface (% of Lot) 43895 Parcel 64303400202 3.01 Pervious Pervious Pervious BUILDING 7 4020 0.09 Native 1.04 0.00 Native 1.98 1.98 Native 0.39 0.00 Pasture 0.43 Pasture 0.00 Pasture 0.00 Impervious Impervious Impervious Total Impervious Surface 28916 0.66 Roads 0.00 Roads 0.00 Roads 0.00 Total Pollution-Generating Permeable Surface 14979 0.34 Roof 0.18 Roof 0.00 Roof 0.00 Sidewalk 0.02 Sidewalk 0.00 Sidewalk 0.00 Parking* 0.07 Parking 0.00 Parking* 0.39 Pond 0.00 Pond 0.00 Pond 0.00 9093 0.21 Total 1.04 0.70 Total 1.98 1.98 Total 0.39 0.39 *Permeable parking is not included in basin element parking totals for modelling purposes; permeable parking makes up a separate element input which receives rainfall directly in WWHM. See attached WWHM report for element breakdown. WwHM2o12 PROJECT REPORT Project Name: Yelm.Creek Apartments - Permeable Pavement Site Name: Yelm Creek Apartments Site Address: 16516 Creek Ln SE City 0Yelm Report Date: 7/9/2020 Gage : Lake Lawrence Data Start : 1955/10/01 Data End : 2008/09/30 Precip Scale: 0.86 Version Date: 2019/09/13 Version : 462.17 Low Flow Threshold for POC 1 50 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name ONSITE Bypass: No Groundwater: No Pervious Land Use acre A B, Forest, Flat 1.04 Pervious Total 1.04 Impervious Land Use acre Impervious Total 0 Basin Total 1.04 Element Flows To: Surface Interflow Name OFFSITE Bypass: No Groundwater: No Pervious Land Use A B, Forest, Flat Groundwater Pervious Total 0.55 Impervious Land Use acre Impervious Total 0 Basin Total 0.55 Element Flows To: Surface Interflow MITIGATED LAND USE Name ONSITE/OFFSITE IMPERVIOUS PARKING Bypass: No Impervious Land Use acre PARKING FLAT LAT 0.61 Element Flows To: Outlet 1 Outlet 2 ONSITE PERMEABLE PAVEM Name ONSITE SIDEWALKS Bypass: No Impervious Land Use acre SIDEWALKS FLAT LAT 0.02 Element Flows To: Outlet 1 Outlet 2 ONSITE PERMEABLE PAVEM Name ONSITE BUILDING 6/7 Bypass: No Impervious Land Use acre ROOF TOPS FLAT LAT 0.18 Element Flows To: Outlet 1 Outlet 2 ONSITE PERMEABLE PAVEM Groundwater Name ONSITE LANDSCAPING Bypass: No Groundwater: No Pervious Land Use acre A B, Pasture, Flat .44 Element Flows To: Surface Interflow ONSITE PERMEABLE PAVEM Groundwater Name ONSITE PERMEABLE PAVEMENT Pavement Area: 0.3437 ft. Pavement Length: 265.00 ft. Pavement Width: 56.50 ft. Pavement slope 1: 0.001 To 1 Pavement thickness: 0.33 Pour Space of Pavement: 0.2 Material thickness of second layer: 1.167 Pour Space of material for second layer: 0.3 Material thickness of third layer: 0.5 Pour Space of material for third layer: 0.2 Infiltration On Infiltration rate: 1.5 Infiltration safety factor: 1 Total Volume Infiltrated (ac -ft.): 197.595 Total Volume Through Riser (ac -ft.): 0 Total Volume Through Facility (ac -ft.): 197.595 Percent Infiltrated: 100 Total Precip Applied to Facility: 0 Total Evap From Facility: 4.991 Element Flows To: Outlet 1 Outlet 2 Permeable Pavement Hydraulic Table Stage(£eet) Area(ac.) Volume (ac -£t.) Discharge(cfs) Infilt(cfs) 0.0000 0.0222 0.0444 0.0667 0.0889 0.1111 0.1333 0.1556 0.1778 0.2000 0.2222 0.343 0.000 0.343 0.001 0.343 0.003 0.343 0.004 0.343 0.006 0.343 0.007 0.343 0.009 0.343 0.010 0.343 0.012 0.343 0.013 0.343 0.015 0.000 0.000 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.000 0.519 0.2444 0.343 0.016 0.000 0.519 0.2667 0.343 0.018 0.000 0.519 0.2889 0.343 0.019 0.000 0.519 0.3111 0.343 0.021 0.000 0.519 0.3333 0.343 0.022 0.000 0.519 0.3556 0.343 0.024 0.000 0.519 0.3778 0.343 0.026 0.000 0.519 0.4000 0.343 0.027 0.000 0.519 0.4222 0.343 0.029 0.000 0.519 0.4444 0.343 0.030 0.000 0.519 0.4667 0.343 0.032 0.000 0.519 0.4889 0.343 0.033 0.000 0.519 0.5111 0.343 0.035 0.103 0.519 0.5333 0.343 0.038 0.178 0.519 0.5556 0.343 0.040 0.230 0.519 0.5778 0.343 0.042 0.272 0.519 0.6000 0.343 0.045 0.308 0.519 0.6222 0.343 0.047 0.341 0.519 0.6444 0.343 0.049 0.371 0.519 0.6667 0.343 0.051 0.398 0.519 0.6889 0.343 0.054 0.424 0.519 0.7111 0.343 0.056 0.448 0.519 0.7333 0.343 0.058 0.471 0.519 0.7556 0.343 0.061 0.493 0.519 0.7778 0.343 0.063 0.514 0.519 0.8000 0.343 0.065 0.535 0.519 0.8222 0.343 0.068 0.554 0.519 0.8444 0.343 0.070 0.573 0.519 0.8667 0.343 0.072 0.591 0.519 0.8889 0.343 0.074 0.609 0.519 0.9111 0.343 0.077 0.626 0.519 0.9333 0.343 0.079 0.643 0.519 0.9556 0.343 0.081 0.659 0.519 0.9778 0.343 0.084 0.675 0.519 1.0000 0.343 0.086 0.690 0.519 1.0222 0.343 0.088 0.706 0.519 1.0444 0.343 0.090 0.720 0.519 1.0667 0.343 0.093 0.735 0.519 1.0889 0.343 0.095 0.749 0.519 1.1111 0.343 0.097 0.763 0.519 1.1333 0.343 0.100 0.777 0.519 1.1556 0.343 0.102 0.791 0.519 1.1778 0.343 0.104 0.804 0.519 1.2000 0.343 0.106 0.817 0.519 1.2222 0.343 0.109 0.830 0.519 1.2444 0.343 0.111 0.842 0.519 1.2667 0.343 0.113 0.855 0.519 1.2889 0.343 0.116 0.867 0.519 1.3111 0.343 0.118 0.879 0.519 1.3333 0.343 0.120 0.891 0.519 1.3556 0.343 0.123 0.903 0.519 1.3778 0.343 0:125 0.915 0.519 1.4000 0.343 0.127 0.926 0.519 1.4222 0.343 0.129 0.938 0.519 1.4444 0.343 0.132 0.949 0.519 1.4667 0.343 0.134 0.960 0.519 1.4889 0.343 0.136 0.971 0.519 1. 5111 0.343 0.139 0.982 0.519 1.5333 0.343 0.141 0.993 0.519 1.5556 0.343 0.143 1.003 0.519 1.5778 0.343 0.145 1.014 0.519 1.6000 0.343 0.148 1.024 0.519 1.6222 0.343 0.150 1.034 0.519 1.6444 0.343 0.152 1.045 0.519 1.6667 0.343 0.155 1.055 0.519 1.6889 0.343 0.156 1.065 0.519 1.7111 0.343 0.158 1.075 0.519 1.7333 0.343 0.159 1.084 0.519 1.7556 0.343 0.161 1.094 0.519 1.7778 0.343 0.162 1.104 0.519 1.8000 0.343 0.164 1.113 0.519 1.8222 0.343 0.165 1.123 0.519 1.8444 0.343 0.167 1.132 0.519 1.8667 0.343 0.168 1.142 0.519 1.8889 0.343 0.170 1.151 0.519 1.9111 0.343 0.171 1.160 0.519 1.9333 0.343 0.173 1.169 0.519 1.9556 0.343 0.174 1.178 0.519 1.9778 0.343 0.176 1.187 0.519 2.0000 0.343 0.184 1.199 0.519 ANALYSIS RESULTS Stream Protection Duration Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.59 Total Impervious Area:O Mitigated Landuse Totals for POC #1 Total Pervious Area:0.44 Total Impervious Area:1.153721 Flow Frequency Return Periods for Predeveloped Return Period Flow(cfs) 2 year 0.002412 5 year 0.006693 10 year 0.012339 25 year 0.025197 50 year 0.041373 100 year 0.06618 Flow Frequency Return Return Period 2 ear 5 10 year Periods for Mitigated. Flow(cfs) 0 0 0 POC #1 PO y year C #1 25 year 0 50 year 0 100 year 0 Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. Year Predeveloped Mitigated 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 0.008 0.002 0.001 0.001 0.001 0.006 0.001 0.001 0.001 0.001 0.001 0.002 0.001 0.001 0.001 0.010 0.017 0.001 0.004 0.001 0.002 0.001 0.002 0.001 0.001 0.003 0.003 0.001 0.001 0.001 0.003 0.003 0.001 0.001 0.009 0.014 0.001 0.001 0.001 0.008 0.019 0.013 0.003 0.001 0.001 0.001 0.008 0.001 0.080 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 POC #1 2005 0.013 0.000 2006 0.058 0.000 2007 0.025 0.000 2008 0.001 0.000 Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated Rank Predeveloped Mitigated 1 0.0805 0.0000 2 0.0579 0.0000 3 0.0250 0.0000 4 0.0192 0.0000 5 0.0169 0.0000 6 0.0137 0.0000 7 0.0130 0.0000 8 0.0127 0.0000 9 0.0104 0.0000 10 0.0091 0.0000 11 0.0082 0.0000 12 0.0079 0.0000 13 0.0079 0.0000 14 0.0057 0.0000 15 0.0044 0.0000 16 0.0033 0.0000 17 0.0030 0.0000 18 0.0030 0.0000 19 0.0029 0.0000 20 0.0027 0.0000 21 0.0021 0.0000 22 0.0018 0.0000 23 0.0018 0.0000 24 0.0017 0.0000 25 0.0013 0.0000 26 0.0013 0.0000 27 0.0013 0.0000 28 0.0013 0.0000 29 0.0013 0.0000 30 0.0013 0.0000 31 0.0013 0.0000 32 0.0013 0.0000 33 0.0013 0.0000 34 0.0013 0.0000 35 0.0013 0.0000 36 0.0013 0.0000 37 0.0013 0.0000 38 0.0013 0.0000 39 0.0013 0.0000 40 0.0013 0.0000 41 0.0013 0.0000 42 0.0013 0.0000 43 0.0012 0.0000 44 0.0012 0.0000 45 0.0012 0.0000 46 0.0012 0.0000 47 0.0012 0.0000 48 0.0012 0.0000 . POC #1 49 0.0012 0.0000 50 0.0012 0.0000 51 0.0012 0.0000 52 0.0012 0.0000 53 0.0011 0.0000 Stream Protection Duration POC #1 The Facility PASSED The Facility PASSED. Flow(cfs) Predev Mit Percentage Pass/Fail 0.0012 687 0 0 Pass 0.0016 148 0 0 Pass 0.0020 120 0 0 Pass 0.0024 98 0 0 Pass 0.0028 80 0 0 Pass 0.0032 61 0 0 Pass 0.0036 51 0 0 Pass 0.0040 48 0 0 Pass 0.0045 44 0 0 Pass 0.0049 38 0 0 Pass 0.0053 37 0 0 Pass 0.0057 33 0 0 Pass 0.0061 32 0 0 Pass 0.0065 30 0 0 Pass 0.0069 29 0 0 Pass 0.0073 27 0 0 Pass 0.0077 26 0 0 Pass 0.0081 22 0 0 Pass 0.0085 19 0 0 Pass 0.0089 18 0 0 Pass 0.0093 16 0 0 Pass 0.0097 16 0 0 Pass 0.0101 14 0 0 Pass 0.0105 13 0 0 Pass 0.0109 11 0 0 Pass 0.0113 9 0 0 Pass 0.0118 9 0 0 Pass 0.0122 9 0 0 Pass 0.0126 9 0 0 Pass 0.0130 8 0 0 Pass 0.0134 6 0 0 Pass 0.0138 5 0 0 Pass 0.0142 5 0 0 Pass 0.0146 5 0 0 Pass 0.0150 5 0 0 Pass 0.0154 5 0 0 Pass 0.0158 5 0 0 Pass 0.0162 5 0 0 Pass 0.0166 5 0 0 Pass 0.0170 4 0 0 Pass 0.0174 4 0 0 Pass 0.0178 4 0 0 Pass 0.0182 4 0 0 Pass 0.0187 4 0 0 Pass 0.0191 4 0 0 Pass 0.0195 3 0 0 Pass 0.0199 3 0 0 Pass 0.0203 3 0 0 Pass 0.0207 3 0 0 Pass 0.0211 3 0 0 Pass 0.0215 3 0 0 Pass 0.0219 3 0 0 Pass 0.0223 3 0 0 Pass 0.0227 3 0 0 Pass 0.0231 3 0 0 Pass 0.0235 3 0 0 Pass 0.0239 3 0 0 Pass 0.0243 3 0 0 Pass 0.0247 3 0 0 Pass 0.0251 2 0 0 Pass 0.0255 2 0 0 Pass 0.0260 2 0 0 Pass 0.0264 2 0 0 Pass 0.0268 2 0 0 Pass 0.0272 2 0 0 Pass 0.0276 2 0 0 Pass 0.0280 2 0 0 Pass 0.0284 2 0 0 Pass 0.0288 2 0 0 Pass 0.0292 2 0 0 Pass 0.0296 2 0 0 Pass 0.0300 2 0 0 Pass 0.0304 2 0 0 Pass 0.0308 2 0 0 Pass 0.0312 2 0 0 Pass 0.0316 2 0 0 Pass 0.0320 2 0 0 Pass 0.0324 2 0 0 Pass 0.0329 2 0 0 Pass 0.0333 2 0 0 Pass 0.0337 2 0 0 Pass 0.0341 2 0 0 Pass 0.0345 2 0 0 Pass 0.0349 2 0 0 Pass 0.0353 2 0 0 Pass 0.0357 2 0 0 Pass 0.0361 2 0 0 Pass 0.0365 2 0 0 Pass 0.0369 2 0 0 Pass 0.0373 2 0 0 Pass 0.0377 2 0 0 Pass 0.0381 2 0 0 Pass 0.0385 2 0 0 Pass 0.0389 2 0 0 Pass 0.0393 2 0 0 Pass 0.0398 2 0 0 Pass 0.0402 2 0 0 Pass 0.0406 2 0 0 Pass 0.0410 2 0 0 Pass 0.0414 2 0 0 Pass Water Quality BMP Flow and Volume for On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. LID Report LID Technique Percent Water Quality Volume Infiltrated POC #1 Used for Percent Treatment? Water Quality Treated ONSITE PERMEABLE PAVEMENT POC N 100.00 Total Volume Infiltrated 100.00 0.00 0% Compliance with LID Standard 8 Duration Analysis Result = Passed Perind and Impind Changes No changes have been made. Total Volume Volume Infiltration Comment Needs Through Volume Treatment Facility (ac -ft.) (ac -ft) (ac -ft 179.81 179.61 0.00 0.00 No Treat. Credit Cumulative Volume Infiltration Credit N This program and accompanying documentation are provided 'as -is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2020; All Rights Reserved. APPENDIX D - CSWPPP YELM CREEK APTS -PHASE 2 07.27.2020 PAGE D-1 Construction Stormwater General Permit Stormwater Pollution Prevention Pian (SWPPP) for YELM CREEK APARTMENTS PHASE 2 Prepared for: The Washington State Department of Ecology Southwest Regional Office Permittee /Owner Develo er O erator /Contractor Yelm Creek Lane, LLC I Yelm Creek Lane, LLC TBD Site Address: 16516 Creek Ln SE Yelm, WA 98597 Certified Erosion and Sediment Control Lead (CESCL) Name Organization SWPPP Prepared By Name Contact Phone Number TBD I TBD I TBD SWPPP Prepared By Name Or anization Contact Phone Number Helena Gubbels, EIT I Hatton Godat Pantier, Inc. I k0oul943-1599 SWPPP Preparation Date July 2020 Prosect Construction Dates Activit /Phase Start Date End Date Clearin/Gradin TBD TBD Construction TBD TBD Stabilization TBD TBD Table of Contents Tableof Contents..........................................................................................................................................2 1 Project Information...............................................................................................................................5 1.1 Existing Conditions........................................................................................................................5 1.2 Proposed Construction Activities..................................................................................................6 2 Construction Stormwater Best Management Practices (BMPs)...........................................................7 2.1 The 13 Elements............................................................................................................................7 2.1.1 Element 1: Preserve Vegetation /Mark Clearing Limits.......................................................7 2.1.2 Element 2: Establish Construction Access........................•..••••••••••••••••••••••••••••••••••••••••••••••��'•8 2.1.3 Element 3: Control Flow Rates..............................................................................................9 2.1.4 Element 4: Install Sediment Controls..............................•.•••••••••••••••••••••••••••••••••�••••�•••••••••••10 2.1.5 Element 5: Stabilize Soils.....................................................................................................11 2.1.6 Element 6: Protect Slopes...................................................................................................12 2.1.7 Element 7: Protect Drain Inlets...........................................................................................13 2.1.8 Element 8: Stabilize Channels and Outlets.........................•..••••••••••••••••••••••••••••••••••••••••••••••14 2.1.9 Element 9: Control Pollutants.............................................................................................15 2.1.10 Element 10: Control Dewatering.........................................................................................18 2.1.11 Element 11: Maintain BMPs................................................................................................19 2.1.12 Element 12: Manage the Project.........................................................................................19 2.1.13 Element 13: Protect Low Impact Development BMPs...........................................•••••••••••••22 3 Pollution Prevention Team..................................................................................................................23 4 Monitoring and Sampling Requirements............................................................................................24 4.1 Site Inspection.............................................................................................................................24 4.2 Stormwater CZuality Sampling.....................................................................................................25 4.2.1 Turbidity Sampling...............................................................................................................25 Page �2 5 4.2.2 pH Sampling.........................................................................................................................26 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies.......................................••27 5.1 303(d) Listed Waterbodies..........................................................................................................27 5.2 TMDL Waterbodies......................................................................................................................27 Reporting and Record Keeping............................................................................................................28 6.1 Record Keeping...........................................................................................................................28 6.1.1 Site Log Book.......................................................................................................................28 6.1.2 Records Retention...............................................................................................................28 6.1.3 Updating the SWPPP...........................................................................................................28 6.2 Reporting.....................................................................................................................................29 6.2.1 Discharge Monitoring Reports............................................................................................29 6.2.2 Notification of Noncompliance...........................................................................................29 List of Tables Table2 —Pollutants.................................................................................................................. 15 Table 3 — pH -Modifying Substances......................................................................................... 16 Table4 —Team Information...................................................................................................... 23 Table 5 —Turbidity Sampling Method........................................................................................ 25 Table 6 — pH Sampling Method................................................................... .............................. 26 List of Appendices Appendix A —Site Map .... ............................... 32 Appendix B —BMP Detail.... 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Appendix C — TESC Plans............................................................... 34 .............................. ............................3 Appendix D —Site Inspection Form ...........••.•.•••••••••••••�••�••�•��•�� Appendix E —Construction Stormwater General Permit (CSWGP) ............................... 48 Page �3 List of Acronyms and Abbreviations Acronym /Abbreviation Explanation 303(d) Section of the Clean Water Act pertaining to Impaired Waterbodies BFO Bellingham Field Office of the Department of Ecology BMP(s) Best Management Practices) CESCL Certified Erosion and Sediment Control Lead COz Carbon Dioxide CRO Central Regional Office of the Department of Ecology CSWGP Construction Stormwater General Permit CWA Clean Water Act DMR Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department of Ecology EPA United States Environmental Protection Agency ERO Eastern Regional Office of the Department of Ecology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GULD General Use Level Designation NPDES National Pollutant Discharge Elimination System NTU Nephelometric Turbidity Units NWRO Northwest Regional Office of the Department of Ecology pH Power of Hydrogen RCW Revised Code of Washington SPCC Spill Prevention, Control, and Countermeasure su Standard Units SWMMEW Stormwater Management Manual for Eastern Washington SWMMWW Stormwater Management Manual for Western Washington SWppp Stormwater Pollution Prevention Plan TESC Temporary Erosion and Sediment Control SWRO Southwest Regional Office of the Department of Ecology TMDL Total Maximum Daily Load VFO Vancouver Field Office of the Department of Ecology WAC Washington Administrative Code WSDOT Washington Department of Transportation WWHM Western Washington Hydrology Model Page �4 1 Project Information Project/Site Name: Yelm Creek Apartments Street/Location: 16516 Creek Lane SE City: Yelm State: WA Subdivision: N/A Receiving waterbody: N/A Zip code: 98597 1.1 Existing Conditions Total acreage (including support activities such as off-site equipment staging yards, material storage areas, borrow areas). Total acreage: 3.01 Disturbed acreage: 1.04 Existing structures: No existing structures. Landscape Previously cleared of trees with shrubby and grassy overgrowth. Topography: High at 345 at the west property line. Low at 339+/- along the Yelm Creek buffer line. There is an existing storm pond in the southeast corner of the site with a bottom of 340. Approximately 0.5% slopes across site. Drainage patterns: Sheet flow west to east. Critical Areas (wetlands, streams, high Yelm Creek erosion risk, steep or difficult to stabilize slopes): List of known impairments for 303(d) listed or Total Maximum Daily Load (TMDL) for the receiving waterbody: None Page �5 1.2 Proposed Construction Activities Description of site development (example: subdivision): 24 -unit, 2 -building addition to an existing multifamily complex, with associated improvements and utility expansions. Additional septic tanks will be constructed to connect into the existing STEP system. Description of construction activities (example: site preparation, demolition, excavation): Site Preparation, demolition, grading, paving, construction. Installation of wet and dry utilities. Description of site drainage including flow from and onto adjacent properties. Must be consistent with Site Map in Appendix A: Sheet flow from west to east. Dispersion and infiltration on site with possible ponding in the temporary asphalt channels and existing stormwater pond onsiteThere is a channel along the southern boundary which collects and ponds stormwater from the adjacent parking area offsite. Description of final stabilization (example: extent of revegetation, paving, landscaping): Final stabilization will include utility installation, paving, building construction, construction of drainage facilities and installation of landscaping/lighting. Contaminated Site Information: Proposed activities regarding contaminated soils or groundwater (example: on-site treatment system, authorized sanitary sewer discharge): NIA Page �6 2 Construction Stormwater Best Management Practices (BMPs) The SWPPP is a living document reflecting current conditions and changes throughout the life of the project. These changes may be informal (i.e., hand-written notes and deletions). Update the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design. 2.1 The 13 Elements 2.1.1 Element 1: Preserve Vegetation /Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land -disturbing activities begin. Trees that are to be preserved shall be clearly delineated, both in the field and on the plans. Protected vegetation will be confirmed by the jurisdiction's Urban Forester. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent possible. Natural vegetation within the wetlands must be retained within the marked high intensity buffers. Grading activities may occur within the outer 25 feet of the buffer line but grades and vegetation must be returned to their native condition. The BMPs relevant to marking the clearing limits that will be applied for this project include: • High Visibility Plastic or Metal Fence (BMP C103) • Silt Fence (BMP C233) The contractor shall install High Visibility Plastic or Metal Fencing and paint the top 2 -feet of fence posts with bright pink or orange paint along the construction limits. With Thurston County Inspector approval, the contractor may combine clearing limits fencing and filter fabric fencing into a single product by using orange filter fabric fence where it is needed and orange plastic fencing where filter fabric fencing is not shown on the approved Temporary Erosion and Sediment Control Plans. Page �7 2.1.2 Element 2: Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads, and street sweeping, and street cleaning shall be employed to prevent sediment from entering state waters. The specific BMPs related to establishing construction access that will be used on this project include: • Stabilized Construction Entrance (BMP C105) Install stabilized construction entrances at the locations and per the details shown on the approved Temporary Erosion and Sediment Control Plans. An existing driveway/road will serve access to onsite construction activities. This stabilized entrance is part of the overall parcel and will keep sediment onsite. Construction traffic will be restricted to stabilized entrances. The contractor shall designated a construction road/parking area stabilization as shown on the plans or locate one deemed suitable for construction activities. Alternate construction access BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. 2.1.3 Element 3: Control Flow Rates Construction flow are not to leave the site without first passing through a flow control BMP. There is an existing channel at the south boundary of the site which will serve to lower flow rates and trap sediment provided a weir is added to the west end to prevent sediment flow towards Yelm Creek. BMPs for flow control include: Wattles (BMP C235) Alternate flow control BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. ct must The project site is located west of the Cascade Mountain Crest. As such, the proje comply with Minimum Requirement 7 (Ecology 2005). In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements (e.g. discharge to combined sewer systems). Will you construct stormwater retention and/or detention facilities? ® Yes❑ No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio -retention, porous pavement) to control flow during construction? ❑ Yes® No Alternate BMPs • Sediment Trap (BMP C240) Page �9 2.1.4 Element 4: Install Sediment Controls Ni stormwater runoff from disturbed areas shall pass through an appropriate sediment removal BMP before leaving the construction site or prior to being discharged to an infiltration facility. The specific BMPs to be used for controlling sediment on this project include: • Silt Fence (BMP C233) • Wattles (BMP C235) Alternate sediment control BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. Alternate BMPs • Sediment Trap (BMP C240) Page � 10 2.1.5 Element 5: Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. The specific BMPs for soil stabilization that shall be used on this project include: • Temporary and Permanent Seeding (BMP C120) • Mulching (BMP C121) • Surface Roughening (BMP C130) • Dust Control (BMP C140) The project site is located west of the Cascade Mountain Crest. From October 1 through April 30, no soils shall remain exposed and unworked for more than 2 days. From May 1 to September 30, no soils shall remain exposed and unworked for more than 7 days. Soils shall be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. These stabilization requirements apply to all soils on site, whether at final grade or not. The local permitting authority may adjust these time limits if it can be shown that a development site's erosion and runoff potential justifies a different standard. From October 1 through April 30, clearing, grading, and other soil -disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that the transportation of sediment from the construction site to receiving waters will be prevented. In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting or seeded and mulched. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. Alternate soil stabilization BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMPs) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. West of the Cascade Mountains Crest Anticipated project dates: TBD Will you construct during the wet season? ® Yes❑ No Page � 11 Number of Days S -oils Can Season Dates be Left Ex osed During the Dry Season Ma 1 — September 30 7 days During the Wet Season October 1 — April 30 2 days Anticipated project dates: TBD Will you construct during the wet season? ® Yes❑ No Page � 11 Alternate BMPs • Nets and Blankets (BMP C122) • Plastic Covering (BMP C123) • Sodding (BMP C124) • Topsoiling/Composting (BMP C125) 2.1.6 Element 6: Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes A rosion. The following specific BMPs will be used to protect slopes for this project: • Temporary and Permanent Seeding (BMP C120) • Mulching (BMP C121) • Surface Roughening (BMP C130) All disturbed areas shall be seeded and mulched per the notes and details in the approved Temporary Erosion and Sediment Control Plans and in BMPs C120 and C121. In no case shall soils remain unworked and unstabilized for more than 7 days during the dry season (May 1 to September 30) or more than 2 days during the wet season ( October 1 to April 30). Alternate slope protection BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMPs) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. Will steep slopes be present at the site during construction? ❑ Yes® No Alternate BMPs • Nets and Blankets (BMP C122) • Plastic Covering (BMP C123) Page � 12 2.1.7 Element 7: Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. The following inlet protection measures will be applied on this project: • Inlet Protection (BMP C220) Install Filter Fabric Fencing/Silt Fence at locations shown and per the details and notes on the approved Temporary Erosion and Sediment Control Plans, Install Storm Drain Inlet Protection/Inlet Sediment Protection/Catch Basin Inserts into all catch basins/curb inlets/storm drain inlets within 1004eet of the site. Inlet protection is the last component of a treatment train and protection of drain inlets include additional sediment and erosion control measures. Inlet protection devices will be cleaned (or removed and replaced), when sediment has filled the device by one third (1/3) or as specified by the manufacturer. Inlets will be inspected weekly at a minimum and daily during storm events. Page � 13 2A As Element 8: Stabilize Channels and Outlets The topography of the site is flat. No flows are anticipated to leave the construction site. If flows are observed to be leaving the site refer to and implement BMPs from the alternate list. If runoff is downstream runoff occurs, the following process will be implemented. Conveyance channels will be designed, constructed and stabilized. The 10 -year, 1 -hour peak flow rate indicated by an approved continuous runoff simulation model, increased by a factor of 1.6, will be used for outlet protection. Stabilization, including armoring material, adequate to prevent erosion of outlets shall be provided at the outlets of all conveyance systems. Alternate channel and outlet stabilization BMPs are included in Appendix B as a quick reference tool for the onsite inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix E). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix E), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix B after the first sign that existing BMPs are ineffective or failing. Alternate BMPs • .Nets and Blankets (BMP C122) Page � 14 2.1.9 Element 9: Control Pollutants All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. BMPs to be implemented to control specific sources of pollutants are discussed below. Maintenance, fueling, and/or repair of heavy equipment and vehicles required to occur on-site shall follow the requirements listed below. If the contractor chooses to store fueling tanks or petroleum product storage containers onsite, they will amend this SWPPP to provide total volume of fuel stored onsite, the capacity of the second containment for each tank, and provide a Spill Prevention, Control, and Countermeasure (SPCC) Plan which complies with the Federal regulations of the Clean Water Act (CWA). Vehicles, construction equipment, and/or petroleum product storage/dispensing per Material Delivery, Storage, and Containment (BMP C153): ■ All vehicles, equipment, and petroleum product storage/dispensing areas will be inspected regularly to detect any leaks or spills, and to identify maintenance needs to prevent leaks or spills. ■ On-site fueling tanks and petroleum product storage containers shall include secondary containment. ■ Spill prevention measures, such as drip pans, will be used when conducting maintenance and repair of vehicles or equipment. ■ In order to perform emergency repairs on site, temporary plastic will be placed beneath and, if raining, over the vehicle. ■ Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on-site? ® Yes❑ No Will wheel wash or tire bath system BMPs be used during construction? ❑ Yes® No Page � 15 Will pH -modifying sources be present on-site? ® Yes❑ No ;If yes, check the source(s).', Table 1 — pH -Modifying Sources Demolition: ■ Dust from construction activities will be controlled using Dust Control Measures (BMP C140). ■ Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (BMP C220 as described above for Element 7). ■ Process water and slurry resulting from sawcutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures (BMP C152). Concrete and grout: ■ Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). ■ Conduct concrete work in designated Concrete Washout Area (BMP C 154) Page � 16 ❑ None ® Bulk cement ❑ Cement kiln dust ❑ Fly ash ❑ Other cementitious materials ® New concrete washing or curing waters ❑ Waste streams generated from concrete grinding and sawing ❑ Exposed aggregate processes ❑ Dewatering concrete vaults ® Concrete pumping and mixer washout waters ❑ Recycled concrete ❑ Recycled concrete stockpiles ❑ Other (i.e., calcium lignosulfate) [please describe: ] Demolition: ■ Dust from construction activities will be controlled using Dust Control Measures (BMP C140). ■ Storm drain inlets vulnerable to stormwater discharge carrying dust, soil, or debris will be protected using Storm Drain Inlet Protection (BMP C220 as described above for Element 7). ■ Process water and slurry resulting from sawcutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures (BMP C152). Concrete and grout: ■ Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). ■ Conduct concrete work in designated Concrete Washout Area (BMP C 154) Page � 16 Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, streets, or streams. Excess concrete must not be dumped on-site, except in designated concrete washout areas with appropriate BMPs installed. Will uncontaminated water from water -only based shaft drilling for construction of building, road, and bridge foundations be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters? ❑ Yes® No Sanitary wastewater: ■ Portable sanitation facilities will be firmly secured, regularly maintained, and emptied when necessary. Solid Waste: Other: ■ Solid waste will be stored in secure, clearly marked containers. ■ Other BMPs will be administered as necessary to address any additional pollutant sources on site. Page � 17 2.1A 0 Element 10: Control Dewatering Discharge foundation, vault, and trench de -watering water, which has similar characteristics to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. Discharge clean, non -turbid de -watering water, such as well -point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Element #8, provided the de -watering flow does not cause erosion or flooding of receiving waters. Do not route clean dewatering water through stormwater sediment ponds. Note that "surface waters of the State" may exist on a construction site as well as off site; for example, a creek running through a site. Handle highly turbid or otherwise contaminated dewatering water separately from stormwater. Other treatment or disposal options may include: 1.Infiltration. 2.Transport off-site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. 3.Ecology-approved on-site chemical treatment or other suitable treatment technologies. 4.Sanitary or combined sewer discharge with local sewer district approval, if there is no other option. 5.Use of a sedimentation bag that discharges to a ditch or swale for small volumes of localized dewatering. Page � 18 2.1.11 Element 11: Maintain BMPs Maintain and repair all temporary and permanent Construction SWPPP BMPs as needed to ensure continued performance of their intended function in accordance with BMP specifications. Remove all temporary Construction SWPPP BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. Note: Some temporary Construction SWPPP BMPs are biodegradable and designed to remain in place following construction, such as compost socks. Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed; and the facility shall be returned to the conditions specified in the construction documents. Remove or stabilize trapped sediment on site, or remove sediment and dispose of it off site if sediment cannot be worked into the project site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. Implement the following BMPs: • Materials on Hand (BMP C150) • Certified Erosion and Sediment Control Lead (BMP C160) 2.1.12 Element 12: Manage the Project The project will be managed based on the following principles: • Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. • Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP. • Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Page � 19 Erosion and sediment control BMPs for this project have been designed based on the following principles: ■ Design the project to fit the existing topography, soils, and drainage patterns. ■ Emphasize erosion control rather than sediment control. ■ Minimize the extent and duration of the area exposed. ■ Keep runoff velocities low. ■ Retain sediment on site. ■ Thoroughly monitor site and maintain all ESC measures. ■ Schedule major earthwork during the dry season. In addition, project management will incorporate the key components listed below: As this project site is located west of the Cascade Mountain Crest, the project will be managed according to the following key project components: Phasing of Construction ■ The construction project is being phased to the extent practicable in order to prevent soil erosion, and, to the maximum extent possible, the transport of sediment from the site during construction. ■ Revegetation of exposed areas and maintenance of that vegetation shall be an integral part of the clearing activities during each phase of construction, per the Scheduling BMP C162. Seasonal Work Limitations ■ From October 1 through April 30, clearing, grading, and other soil disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that silt -laden runoff will be prevented from leaving the site through a combination of the following: ❑ Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters; and ❑ Limitations on activities and the extent of disturbed areas; and ❑ Proposed erosion and sediment control measures. Page X20 ■ Based on the information provided and/or local weather conditions, the local permitting authority may expand or restrict the seasonal limitation on site disturbance. ■ The following activities are exempt from the seasonal clearing and grading limitations: ❑ Routine maintenance and necessary repair of erosion and sediment control BMPs; ❑ Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative cover to soil; and ❑ Activities where there is 100 percent infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. Coordination with Utilities and Other Jurisdictions ■ Care has been taken to coordinate with utilities, other construction projects, and the local jurisdiction in preparing this SWPPP and scheduling the construction work. Inspection and Monitoring ■ All BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections shall be conducted by a person who is knowledgeable in the principles and practices of erosion and sediment control. This person has the necessary skills to: ❑ Assess the site conditions and construction activities that could impact the quality of stormwater, and ❑ Assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. ■ A Certified Erosion and Sediment Control Lead shall be on-site or on-call at all times. ■ Whenever inspection and/or monitoring reveals that the BMPs identified in this SWPPP are inadequate, due to the actual discharge of or potential to discharge a significant amount of any pollutant, appropriate BMPs or design changes shall be implemented as soon as possible. Page � 21 Maintaining an Updated Construction SWPPP ■ This SWPPP shall be retained on-site or within reasonable access to the site. ■ The SWPPP shall be modified whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. ■ The SWPPP shall be modified if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) days following the inspection. 2.1.13 Element 13: Protect Low Impact Development BMPs Low Impact Development (LID) BMP's for this site include all lawn and landscape areas. Protect all completed LID BMPs from compaction, excavation and all other construction activities to the greatest extent possible. Clearly marked and protect completed LID areas from construction traffic. Mark lawn and landscape areas with High Visibility Plastic or Metal Fencing. Provide buffer zones to ensure construction activities remain off the lawn and landscape areas. Keep grading to a minimum, incorporate natural topography where applicable. Implement the following BMPs: 1. Clearly mark and protect completed LID areas from construction traffic. 2. Mark LID areas with high visibility plastic or metal fencing. 3. Provide buffer zones to ensure construction activities 4. Clearly document and plan to meet and walk through the site with equipment operations prior to construction to clarify construction boundaries, limits of disturbance and construction activities in the vicinity of LID areas. 5. General/primary construction must inform other subcontractors of applicable LID BMP protection requirements. 6. Complete construction and erosion control activities in one section of the site before beginning activity in another section. 7. Preserve any portion of the site with permeable soils to promote infiltration of stormwater runoff. 8. Leave areas of rich topsoil in place, or if excavated, utilize elsewhere on the site to amend areas with sparse or nutrient deficient topsoil. Implement BMPs • Buffer Zone (BMP C102) • High Visibility Fence (BMP C103) • Silt Fence (BMP C233) Alternate BMPs • Interceptor Dike and Swale (BMP C200) 3 Pollution Prevention Team Table 2 — Team Information Title Names Phone Number Certified Erosion and Sediment Control Lead CESCL TBD TBD Resident Engineer Hatton Godat Pantier -Steve Hatton 360 943-1599 Emergency Ecology Contact TBD TBD Emergency Permittee/ Owner Contact TBD TBD Non=Emergency Owner Contact The Rants Group (360) 943-8060 Monitoring Personnel TBD TBD Ecology Regional Office Southwest Re ional Office 360 407-6300 4 Monitoring and Sampling Requirements Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Stormwater sampling data For convenience, the inspection form and water quality monitoring forms included in this SWPPP include the required information for the site log book. This SWPPP may function as the site log book if desired, or the forms may be separated and included in a separate site log book. However, if separated, the site log book but must be maintained on-site or within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See CSWGP Special Condition S8 and Section 5 of this template. 4.1 Site Inspection All BMPs will be inspected, maintained, and repaired as needed to assure continued performance of their intended function. The inspector will be a Certified Erosion and Sediment Control Lead (CESCL) per BMP C160. The name and contact information for the CESCL is provided in Section 5 of this SWPPP. Site inspection will occur in all areas disturbed by construction activities and at all stormwater discharge points. Stormwater will be examined for the presence of suspended sediment, turbidity, discoloration, and oily sheen. The site inspector will evaluate and document the effectiveness of the installed BMPs and determine if it is necessary to repair or replace any of the BMPs to improve the quality of stormwater discharges. All maintenance and repairs will be documented in the site log book or forms provided in this document. All new BMPs or design changes will be documented in the SWPPP as soon as possible. Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The site inspector will record each site inspection using the site log inspection forms provided in Appendix D. The site inspection log forms may be separated from this SWPPP document, but will be maintained on-site or within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. There are no planned discharge point(s) from the site, although runoff from the site could occur south of the storm pond, east of the building, or at either entrance. The south and east property lines should be monitored for signs that sediment laden water is/has left the site, and BMPs should be modified to prevent this from happening. Page X24 4.2 Stormwater Quality Sampling 4.2.1 Turbidity Sampling Requirements include calibrated turbidity meter or transparency tube to sample site discharges for compliance with the CSWGP. Inspection/sampling will be conducted when/where any discharge is notice from the site. Method for sampling turbidity: Table 3 —Turbidity Sampling Method ® Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size) ❑ Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size) The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency less than 33 centimeters. If the discharge's turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to or greater than 6 cm, the following steps will be conducted: 1. Review the SWPPP for compliance with Special Condition S9. Make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10 -day response period. 3. Document BMP implementation and maintenance in the site log book. If the turbidity exceeds 250 KITH or the transparency is 6 cm or less at any time, the following steps will be conducted: 1. Telephone or submit an electronic report to the applicable Ecology Region's Environmental Report Tracking System (ERTS) within 24 hours. • Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 or http://www,ecy.wa,gov/programs/spills/forms/nerts online/SWRO nerts online.html 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10 -day response period 3. Document BMP implementation and maintenance in the site log book. 4. Continue to sample discharges daily until one of the following is true: • Turbidity is 25 NTU (or lower). • Transparency is 33 cm (or greater) Page X25 • Compliance with the water quality limit for turbidity is achieved. 0 1 - 5 NU over background turbidity, if background is less than 50 NTU 0 1 % - 10% over background turbidity, if background is 50 NTU or greater • The discharge stops or is eliminated. 4.2.2 pH Sampling pH monitoring is required for "Significant concrete work" (i.e., greater than 1000 cubic yards poured concrete over the life of the project). The use of recycled concrete or engineered soils (soil amendments including but not limited to Portland cement -treated base [CTB], cement kiln dust [CKD] or fly ash) also requires pH monitoring. For significant concrete work, pH sampling will start the first day concrete is poured and continue until it is cured, typically three (3) weeks after the last pour. For engineered soils and recycled concrete, pH sampling begins when engineered soils or recycled concrete are first exposed to precipitation and continues until the area is fully stabilized. If the measured pH is 8.5 or greater, the following measures will be taken: 1. Prevent high pH water from entering storm sewer systems or surf ace water. 2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate technology such as carbon dioxide (CO2) sparging (liquid or dry ice). 3. Written approval will be obtained from Ecology prior to the use of chemical treatment other than CO2 sparging or dry ice. Method for sampling pH: Table 4 — pH Sampling Method ❑ pH meter ❑ pH test kit ® Wide range pH indicator paper Page X26 5 Discharges to 303(d) or Total Maximum Daily Load kMDL) Waterbodies 5.1 303(d) Listed Waterbodies There are no planned discharge points from this project, though construction stormwater could sheet flow away from landscaped areas. Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? List the impairment(s): N/A 5.2 TMDL Waterbodies Waste Load Allocation for CWSGP discharges: N/A List and describe BMPs: N/A Page X27 6 Reporting and Record Keeping 6.1 Record Keeping 6.1.1 Site Log Book A site log book will be maintained for all on-site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Sample logs 6.1.2 Records Retention Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.0 of the CSWGP. Permit documentation to be retained on-site: • CSWGP • Permit Coverage Letter • SWPPP • Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. 6.1.3 Updating the SWPPP The 0PP will be modified if: • Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. • There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspections) or investigations) determine additional or modified BMPs are necessary for compliance. An updated timeline for BMP implementation will be prepared. Page X28 6.2 Reporting 6.2.1 Discharge Monitoring Reports Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting "No Discharge". The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology's WQWebDMR System. 6.2.2 Notification of Noncompliance If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24 -hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP. • Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, or Yakima County • Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman County • Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County • Southwest Region at (360) 407-6300 for Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum Include the following information: 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Page X30 Appendix/Glossary A. Site Map Page 131 \\ \ N., It IN \ \ / (Ato to 1 of I I It m11P* to No I z /+ ,y . Irt If ot o to Z Ito a \ L, --of. If , i o —W x / +/'... ' \. . W \to I IN z of I Fod IN LU *^ � W // + d joll to/ am It C W k; � ii / �_ ..\ Oil �LL O W It 91IN0 ib A1101SC M3N Lq mtriW ot Wam io CL to �� IIIIIII I��k II�� rl I� II NId III II .-IIS, IT Ilulriyl,l -r�41 Irl III ihl� III II ill: slll i/IIII rnl� 6 III I�IIII I, rkg III �i Ilul n Ito III li Ih,l loll llll III@I p Ir vi 14111 III§Ir lull li"I S Ild! W Illiiilllj slllll �I IIID ;I I� I�I �I \ d l%1111 III IIIIIII III 111 r Illrl 11 ll,llir"IIPI lir to of yyy. Ill. h Ig@II qq is gg h W W/+ �'II1411 I'I';I III II, II'lll III I� Ilil; r l " VIII too At IN Prof IN IIIIIII Ii�1ll�l I ISI Il li''I III 1111�i � I III I�.' I I I it°NI II ' j /+ 1911. / II it . V EM1 / �' �7',q. 2 _ IIS I. III %N i aIfsl lI S /Fa. 4nIt M rc ulllVlhlll �llill11 fill No IRV It I to cd VIC, A 41 02 WW rnlollh��aW�, -- 1- st. Nb IF /y-oIN it J o F %�6 " " ri 0 /Ill Q to 0 ' P� F?��.> 6�� UE] I SIE z wIFIN J1 LU �n 00, ff IIN l I�`tti q If > Z 2�V` i CO' // �Iy '�� O 0 Z �.�yy W'7 x,_11 --- D F, to i S - H t� i�'�! it " L 1`y �qb i " i W X NINN4 MwLU d IN INN ;P1IN N, IN Ill SOIN IN 11 um 11) fieu N 0, PL ! ] I ii J 111 _ \�c1:D x N —_— �-11� 3.90.f0.10N 3S 133111S N33HO z �F ------------------- I----- ------ -------------- - - - --- - - ----- -- ---- - --- - --- B. BMP Detail Page X32 If tree roots have been exposed or injured, "prune" cleanly with an appropriate pruning saw or top- pers directly above the damaged roots and recover with native soils. Treatment of sap flowing trees (fir, hemlock, pine, soft maples) is not advised as sap forms a natural healing barrier. BMP C102: Buffer Zones Purpose Creation of an undisturbed area or strip of natural vegetation or an established suitable planting that will provide a living filter to reduce soil erosion and stormwater runoff velocities. Conditions of Use Buffer zones are used along streams, wetlands and other bodies of water that need protection from erosion and sedimentation. Contractors can use vegetative buffer zone BMPs to protect natural swales and they can incorporate them into the natural landscaping of an area. Do not use critical -areas buffer zones as sediment treatment areas. These areas shall remain com- pletely undisturbed. The local permitting authority may expand the buffer widths temporarily to allow the use of the expanded area for removal of sediment. The types of buffer zones can change the, level of protection required as shown below: Designated Critical Area Buffers -buffers that protect Critical Areas, as defined by the Washington State Growth Management Act, and are established and managed by the local permitting authority. These should not be disturbed and must protected with sediment control BMPs to prevent impacts. The local permitting authority may expand the buffer widths temporarily to allow the use of the expan- ded area for removal of sediment. Vegetative Buffer Zones -areas that may be identified in undisturbed vegetation areas or managed vegetation areas that are outside any Designated Crcal Area Buffer. They maybe utilized to provide an additional sediment control area and/or reduce runoff velocities. If being used for pre- servation of natural vegetation, they should be arranged in clumps or strips. They can be used to pro- tect natural swales and incorporated into the natural landscaping area. Design and Installation Specifications . Preserving natural vegetation or plantings in clumps, blocks, or strips is generally the easiest and most successful method. . Leave all unstable steep slopes in natural vegetation. . Mark clearing limits and keep all equipment and construction debris out of the natural areas and buffer zones. Steel construction fencing is the most effective method to protect sensitive areas and buffers. Alternatively, wire -backed silt fence on steel posts is marginally effective. Flagging alone is typically not effective. . Keep all excavations outside the dripline of trees and shrubs. . Do not push debris or extra soil into the buffer zone area because it will cause damage by 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 273 burying and smothering vegetation. . Vegetative buffer zones for streams, lakes or other waterways shall be established by the local permitting authority or other state or federal permits or approvals. Maintenance Standards Inspect the area frequently to make sure flagging remains in place and the area remains undis- turbed. Replace all damaged flagging immediately. Remove all materials located in the buffer area that may impede the ability of the vegetation to act as a filter. BMP C103: High -Visibility Fence Purpose High -visibility fencing is intended to: Restrict clearing to approved limits. . Prevent disturbance of sensitive areas, their buffers, and other areas required to be left undis- turbed. . Limit construction trafficto designated construction entrances, exits, or internal roads. . Protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits plastic, fabric, or metal fence may be used: . At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared. . As necessary to control vehicle access to and on the site. Design and Installation Specifications High -visibility plastic fence shall be composed of ahigh-density polyethylene material and shall beat least four feet in height. Posts for the fencing shall be steel or wood and placed every 6 feet on center (maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fence color shall be high -visibility orange. The fence tensile strength shall be 360 lbs/ft using the ASTM D4595 testing method. If appropriate install fabric silt fence in accordance with BMP C233: Silt Fence to act ashigh-visibility fence. Silt fence shall be at least 3 feet high and must be highly visible to meet the requirements of this BMP. Metal fences shall be designed and installed according to the manufacturer's specifications. Metal fences shall be at least 3 feet high and must be highly visible. Fences shall not be wired or stapled to trees. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 274 Maintenance Standards If the fence has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. BMP C1050 Stabilized Construction Access Purpose Stabilized construction accesses are established to reduce the amount of sediment transported onto paved roads outside the project site by vehicles or equipment. This is done by constructing a sta- bilized pad of quarry spalls at entrances and exits for project sites. Conditions of Use Construction accesses shall be stabilized wherever traffic will be entering or leaving a construction site if paved roads or other paved areas are within 1,000 feet of the site. For residential subdivision construction sites, provide a stabilized construction access for each res- idence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient length/width to provide vehicle access/parking, based on lot size and configuration. On large commercial, highway, and road projects, the designer should include enough extra mater- ials in the contract to allow for additional stabilized accesses not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and Installation Specifications See Figure 11-1 1 P Stabilized Construction Access for details. Note: the 100' minimum length of the access shall be reduced to the maximum practicable size when the size or configuration of the site does not allow the full length (100'). Construct stabilized construction accesses with a 12 -inch thick pad of 4 -inch to 8 -inch quarry spalls, a 4 -inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed con- crete, cement, or calcium chloride for construction access stabilization because these products raise pH levels in stormwater and concrete discharge to waters of the State is prohibited. A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the standards listed in Table I I-3.2: Stabilized Con- struction Access Geotextile Standards. Table 11-3.2: Stabilized Construction Access Geotextile Standards Geotextile Property � Required Value Grab Tensile Strength (ASTM D4751) � 200 psi min. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 275 Table 11-3.2: Stabilized Construction Access GeotexLIM Standards (continued) Geotextile Property Required Value Grab Tensile Elongation (ASTM D4632) 30% max. Mullen Burst Strength (ASTM D378&80a) 400 psi min. AOS (ASTM D4751) 2045 (U.S. standard sieve size) . Consider early installation of the first lift of asphalt in areas that will be paved; this can be used as a stabilized access. Also consider the installation of excess concrete as a stabilized access. During large concrete pours, excess concrete is often available for this purpose. . Fencing (see BMP C103:High-Visibility Fence) shall be installed as necessary to restrict traffic to the construction access. . Whenever possible, the access shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance. . Construction accesses should avoid crossing existing sidewalks and back of walk drains if at all possible. If a construction access must cross a sidewalk or back of walk drain, the full length of the sidewalk and back of walk drain must be covered and protected from sediment leaving the site. Alternative Material Specification WSDOT has raised safety concerns about the Quarry Spall rock specified above. WSDOT observes that the 4 -inch to 8 -inch rock sizes can become trapped between Dually truck tires, and then released off-site at highway speeds. WSDOT has chosen to use a modified specification for the rock while continuously verifying that the Stabilized Construction Access remains effective. To remain effective, the BMP must prevent sediment from migrating off site. To date, there has been no per- formance testing to verify operation of this new specification. Jurisdictions may use the alternative specification, but must perform increased off-site inspection if they use, or allow others to use, it. Stabilized Construction Accesses may use material that meets the requirements of WSDOT's Stand- ard Specifications for Road, Bridge, and Municipal Construction Section 9-03.9(1) (WSDOT, 2016) for ballast except for the following special requirements. The grading and quality requirements are listed in Table II -3.3: Stabilized Construction Access Alternative Material Requirements. Table 11-3.3: Stabilized Construction Access Alternative Material Requirements Sieve Size Percent Passing 2'/2" 99-100 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 276 Table 11-3.3: Stabilized Construction Access Alternative Material Requirements (continued) Sieve Size Percent Passing 2" 65-100 3/<" 40-80 No. 4 5 max. No. 100 0-2 Yo Fracture 75 min. . All percentages are by weight. . The sand equivalent value and dust ratio requirements do not apply. . The fracture requirement shall be at least one fractured face and will apply the combined aggregate retained on the No. 4 sieve in accordance with FOP for AASHTO T 335. Maintenance Standards Quarry spalls shall be added if the pad is no longer in accordance with the specifications. . If the access is not preventing sediment from being tracked onto pavement, then alternative measures to keep the streets free of sediment shall be used. This may include replace- ment/cleaning of the existing quarry spalls, street sweeping, an increase in the dimensions of the access, or the installation of BMP C106: Wheel Wash. . Any sediment that is tracked onto pavement shall be removed by shoveling or street sweep- ing. The sediment collected by sweeping shall be removed or stabilized onsite. The pavement shall not be cleaned by washing down the street, except when high efficiency sweeping is inef- fective and there is a threat to public safety. If it is necessary to wash the streets, the con- struction of a small sump to contain the wash water shall be considered. The sediment would then be washed into the sump where it can be controlled. . Perform street sweeping by hand orwith a high efficiency sweeper. Do not use anon -high effi- ciencymechanical sweeper because this creates dust and throws soils into storm systems or conveyance ditches. . Any quarry spalls that are loosened from the pad, which end upon the roadway shall be removed immediately. . If vehicles are entering or exiting the site at points other than the construction access(es), BMP C103:High-Visibility Fence shall be installed to control traffic. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 277 Upon project completion and site stabilization, all construction accesses intended as per- manent access for maintenance shall be permanently stabilized. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 278 Figure 11-3.1: Stabilized Construction Access 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 279 NOT TO SCALE oa d �X�St�r9R .� 100' min. / Install driveway culvert if there is a roadside ditch present 4" - 8" quarry spalls Geotextile Notes: 15' min. 1. Driveway shall meet 12" minimum thickness the requirements of the permitting agency. 2. It is recommended that Provide full width the access be crowned of ingress/egress so that runoff drains off area the pad. Stabilized Construction Access Revised June 2018 DEPARTMENT OF ECOLOGY Please see http://www.ecy.wa.govicopyrighthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 279 Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept these products, or may require additional testing prior to consideration for local use. Products that Ecology has approved as functionally equivalent are available for review on Ecology's website at: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C1060 Wheel Wash Purpose Wheel washes reduce the amount of sediment transported onto paved roads bywashing dirt from the wheels of motor vehicles prior to the motor vehicles leaving the construction site. Conditions of Use . Use a wheel wash when BMP C105: Stabilized Construction Access is not preventing sed - invent from being tracked off site. . Wheel washing is generally an effective BMP when installed with careful attention to topo- graphy. For example, a wheel wash can be detrimental if installed at the top of a slope abut- ting a right-of-way where the water from the dripping truck can run unimpeded into the street. . Pressure washing combined with an adequately sized and surfaced pad with direct drainage to a large 10 -foot x 10 -foot sump can be very effective. . Wheel wash wastewater is not stormwater. It is commonly called process water, and must be discharged to a separate on-site treatment system that prevents discharge to waters of the State, or to the sanitary sewer with local sewer district approval. . Wheel washes may use closed-loop recirculation systems to conserve water use. . Wheel wash wastewater shall not include wastewater from concrete washout areas. . When practical, the wheel wash should be placed in sequence with BMP C105: Stabilized Construction Access. Locate the wheel wash such that vehicles exiting the wheel wash will enter directly onto BMP C105: Stabilized Construction Access. In order to achieve this, BMP C105: Stabilized Construction Access may need to be extended beyond the standard instalk ation to meet the exit of the wheel wash. Design and Installation Specifications Suggested details are shown in Figure II -3.2: Wheel Wash. The Local Permitting Authority may allow other designs. A minimum of 6 inches of asphalt treated base (ATB) over crushed base mater- ial or 8 inches over a good subgrade is recommended to pave the wheel wash. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 280 Crushed rock, gravel base, etc., shall be added as required to maintain a stable driving surface and to stabilize any areas that have eroded. Following construction, these areas shall be restored to pre -construction condition or better to pre- vent future erosion. Perform street cleaning at the end of each day or more often if necessary. BMP C1200 Tempolralry and Permanent Seeding Purpose Seeding reduces erosion by stabilizing exposed soils. Awell-established vegetative cover is one of the most effective methods of reducing erosion. Conditions of Use Use seeding throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. The optimum seeding windows for western Washington are April 1 through June 30 and September 1 through October 1. Between July 1 and August 30 seeding requires irrigation until 75 percent grass cover is established. Between October 1 and March 30 seeding requires a cover of mulch or an erosion control blanket until 75 percent grass cover is established. Review all disturbed areas in late August to early September and complete all seeding by the end of September. Otherwise, vegetation will not establish itself enough to provide more than average pro- tection. Mulch is required at all times for seeding because it protects seeds from heat, moisture loss, and transport due to runoff. Mulch can be applied on top of the seed or simultaneously by hydroseeding9 See BMP C121: Mulching for specifications. Seed and mulch all disturbed areas not otherwise vegetated at final site stabilization. Final sta- bilization means the completion of all soil disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles) which will prevent erosion. See BMP T5.13: Post -Construction Soil Quality and Depth. Design and Installation Specifications General . Install channels intended for vegetation before starting major earthwork and hydroseed with a Bonded Fiber Matrix. For vegetated channels that will have high flows, install erosion control blankets over the top of hydroseed. Before allowing water to flow in vegetated channels, establish 75 percent vegetation cover. If vegetated channels cannot be established by seed 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 284 before water flow; install sod in the channel bottom— over top of hydromulch and erosion con- trol blankets. . Confirm the installation of all required surface water control measures to prevent seed from washing away. . Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 per- cent tackifier. See BMP C121: Mulching for specifications. . Areas that will have seeding only and not landscaping may need compost ormeal-based mulch included in the hydroseed in order to establish vegetation. Re -install native topsoil on the disturbed soil surface before application. See BMP T5.13: Post -Construction Soil Quality and Depth. . When installing seed via hydroseeding operations, only about 1 /3 of the seed actually ends up in contact with the soil surface. This reduces the ability to establish a good stand of grass quickly. To overcome this, consider increasing seed quantities by up to 50 percent. . Enhance vegetation establishment by dividing the hydromulch operation into two phases: Phase 1 -Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in the first lift. Phase 2- Install the rest of the mulch and tackifier over the first lift. Or, enhance vegetation by: o Installing the mulch, seed, fertilizer, and tackifier in one lift. Spread or blow straw over the top of the hydromulch at a rate of 800-1000 pounds per acre. Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance vegetative establishment. The increased cost maybe offset by the reduced need for: o Irrigation. Reapplication of mulch. Repair of failed slope surfaces. This technique works with standard hydromulch (1,500 pounds per acre minimum) and Bon- ded Fiber Matrix/ Mechanically Bonded Fiber Matrix (BFM/MBFMs) (3,000 pounds per acre minimum). . Seed maybe installed by hand if: o Temporary and covered by straw, mulch, or topsoil. Permanent in small areas (usually less than 1 acre) and covered with mulch, topsoil, or erosion blankets. . The seed mixes listed in Table II -3.4: Temporary and Permanent Seed Mixes include 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 285 recommended mixes for both temporary and permanent seeding. . Apply these mixes, with the exception of the wet area seed mix, ata rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow-release fertilizers are used. Apply the wet area seed mix at a rate of 60 pounds per acre. . Consult the local suppliers or the local conservation district for their recommendations. The appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local authority may be used, depending on the soil type and hydrology of the area. Table II -3.4: Temporary and Permanent Seed Mixes Common Name Latin Name % Weight I % Purity % Germination Temporary Erosion Control Seed Mix A standard mix for areas requiring a temporary vegetative cover. Festuca rubra var. Chewings or commutata or Poa 40 98 90 annual bluegrass anna Perennial rye Lolium perenne 50 98 90 Redtop or colonial Agrostis alba or 5 92 85 bentgrass Agrostis tenuis White dutch clover Trifolium repens 5 98 90 Landscaping Seed Mix A recommended mix for landscaping seed. Perennial rye blend Lolium perenne 70 98 90 Festuca rubra var. Chewings and red commutata or Fes- 30 98 90 fescue blend tuca rubra Low -Growing Turf Seed Mix A turf seed mix for dry situations where there is no need for watering. This mix requires very little main- tenance. Dwarf tall fescue Festuca arundin- 45 98 90 (several varieties) acea var. Dwarf perennial Lolium perenne 30 98 90 rye (Barclay) var. barclay Red fescue Festuca rubra 20 98 90 Colonial bentgrass Agrostis tenuis 5 98 90 Bioswale Seed Mix A seed mix for bioswales and other intermittently wet areas. Tall or meadow fes- Festuca arundin- 75-80 98 90 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 286 Table II -3.4: Temporary and Permanent Seed Mixes (continued) Common Name Latin Name % Weight % Purity % Germination acea or Festuca cue elatior Seaside/Creeping Agrostis palustris 10-15 92 85 bentgrass Redtop bentgrass Agrostis alba or 5-10 90 80 Agrostis gigantea Wet Area Seed Mix A low -growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wet- lands. Consult Hydraulic Permit Authority (HPA) for seed mixes if applicable. Festuca arundin- Tall or meadow fes- acea or Festuca 60-70 98 90 cue elatior Seaside/Creeping Agrostis palustris 10-15 98 85 bentgrass Alepocurus praten- Meadow foxtaiI 10-15 90 80 sis Alsike clover Trifolium hybridum 1-6 98 90 Redtop bentgrass Agrostis alba 1-6 92 85 Meadow Seed Mix A recommended meadow seed mix for infrequently maintained areas or non -maintained areas where cok onization by native plants is desirable. Likely applications include rural road and utility right-of-way. Seed- ing should take place in September or very early October in order to obtain adequate establishment priorto the winter months. Consider the appropriateness of clover, a fairly invasive species, in the mix. Amending the soil can reduce the need for clover. Agrostis alba or Redtop or Oregon Agrostis ore- 20 92 85 bentgrass gonensis Red fescue Festuca rubra 70 98 90 =hitech clover Trifolium repens 10 98 90 Roughening and Rototilling . The seedbed should be firm and rough. Roughen all soil no matter what the slope. Track walk slopes before seeding if engineering purposes require compaction. Backblading or smoothing of slopes greater than 4H A V is not allowed if they are to be seeded. . Restoration -based landscape practices require deeper incorporation than that provided by a simple single -pass rototilling treatment. Wherever practical, initially rip the subgrade to improve long-term permeability, infiltration, and water inflow qualities. At a minimum, 2019 Sformwafer Management Manual for Western Washington Volume 11 - Chapfer 3 -Page 287 permanent areas shall use soil amendments to achieve organic matter and permeability per- formance defined in engineered soil/landscape systems. For systems that are deeper than 8 inches complete the rototilling process in multiple lifts, or prepare the engineered soil system per specifications and place to achieve the specified depth. Fertilizers . Conducting soil tests to determine the exact type and quantity of fertilizer is recommended. This will prevent the over -application of fertilizer. . Organic matter is the most appropriate form of fertilizer because it provides nutrients (includ- ing nitrogen, phosphorus, and potassium) in the least water-soluble form. . In general, use 10-4-6 N -P -K (nitrogen -phosphorus -potassium) fertilizer at a rate of 90 pounds per acre. Always use slow-release fertilizers because they are more efficient and have fewer environmental impacts. Do not add fertilizer to the hydromulch machine, or agit- ate, more than 20 minutes before use. Too much agitation destroys the slow-release coating. . There are numerous products available that take the place of chemical fertilizers. These include several with seaweed extracts that are beneficial to soil microbes and organisms. If 100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal provides a good source of long-term, slow-release, available nitrogen. Bonded Fiber Matrix and Mechanically Bonded Fiber Matrix . On steep slopes use Bonded Fiber Matrix (BFM) or Mechanically Bonded Fiber Matrix (MBFM) products. Apply BFM/MBFM products at a minimum rate of 3,000 pounds per acre with approximately 10 percent tackifies. Achieve a minimum of 95 percent soil coverage during application. Numerous products are available commercially. Most products require 24-36 hours to cure before rainfall and cannot be installed on wet or saturated soils. Generally, products come in 40-50 pound bags and include all necessary ingredients except for seed and fertilizer. . Install products per manufacturer's instructions. . BFMs and MBFMs provide good alternatives to blankets in most areas requiring vegetation establishment. Advantages over blankets include: o BFM and MBFMs do not require surface preparation. o Helicopters can assist in installing BFM and MBFMs in remote areas. o On slopes steeper than 2.5H:1 V, blanket installers may require ropes and harnesses for safety. Installing BFM and MBFMs can save at least $1,000 per acre compared to blankets. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 288 Maintenance Standards Reseed any seeded Of that fail to establish at least 75 percent cover (100 percent cover for areas that receive sheet or concentrated flows). If reseeding is ineffective, use an alternate method such as sodding, mulching, nets, or blankets. Reseed and protect by mulch any areas that experience erosion after achieving adequate cover. Reseed and protect by mulch any eroded area. . Supply seeded areas with adequate moisture, but do not water to the extent that it causes run- off. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept these products, or may require additional testing prior to consideration for local use. Products that Ecology has approved as functionally equivalent are available for review on Ecology's website at: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C121: Mulching Purpose Mulching soils provides immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and moderating soil temperatures. There are a variety of mulches that can be used. This section discusses only the most common types of mulch. Conditions of Use As a temporary cover measure, mulch should be used: . For less than 30 days on disturbed areas that require cover. . At all times for seeded areas, especially during the wet season and during the hot summer months. . During the wet season on slopes steeper than 3H:1 V with more than 10 feet of vertical relief. Mulch may be applied at anytime of the year and must be refreshed periodically. For seeded areas, mulch maybe made up of 100 percent: . cottonseed meal; . fibers made of wood, recycled cellulose, hemp, or kenaf; 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 289 . compost; . or blends of these. Tacer shall be plant -based, such as guar or alpha plantago, or chemical -based such as poly- acrylamide or polymers. Generally, mulches come in 40-50 pound bags. Seed and fertilizer are added at time of application. Recycled cellulose may contain polychlorinated biphenyl (PCBs). Ecology recommends that products should be evaluated for PCBs prior to use. Refer to BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection for conditions of use. PAM shall not be directly applied to water or allowed to enter a water body. Any mulch or tackifier product used shall be installed per the manufacturer's instructions. Design and Installation Specifications For mulch materials, application rates, and specifications, see Table I I-3.6: Mulch Standards and Guidelines. Consult with the local supplier or the local conservation district for their recom- mendations. Increase the application rate until the ground is 95% covered (i.e. not visible under the mulch layer). Note: Thickness may be increased for disturbed areas in or near sensitive areas or other areas highly susceptible to erosion. Where the option of "Compost" is selected, it should be a coarse compost that meets the size grad- ations listed in Table II -3.5: Size Gradations of Compost as Mulch Material when tested in accord- ance with Test Method 02.02-13 found in Test Methods for the Examination of Composting and Compost (Thompson, 2001). Table 11-3.5: Size Gradations of Compost as Mulch Material Sieve Size Percent Passing 3" 100% 1" 90% -100% 3/4" 70% -100% 1/4 40% -100% Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Composted organic materials have higher specific gravities (densities) than straw, wood, or chipped material. Consult the Hydraulic Permit Authority (H PA) for mulch mixes if applicable. Maintenance Standards The thickness of the mulch cover must be maintained. Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related, then the problem shall be fixed and the eroded area remulched. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 290 Table 1143.6: Mulch Standards and Guidelines Mulch Mater- Guideline Description ial Quality Air-dried; free from undesirable seed and coarse material. Standards Application 211 3Y thick; 5 bales per 1,000 sf or 2-3 tons per acre Rates Cost-effective protection when applied with adequate thickness. Hand - application generally requires greater thickness than blown straw. The Straw thickness of straw may be reduced by half when used in conjunction with seeding. In windy areas straw must be held in place by crimping, using a tackifier, or covering with netting. Blown straw always has to be held in Remarks place with a tackifier as even light winds will blow it away. Straw, however, has several deficiencies that should be considered when selecting mulch materials. It often introduces and/or encourages the propagation of weed species and it has no significant long-term benefits It should also not be used within the ordinary high-water elevation of surface waters (due to flot- ation). Quality No growth inhibiting factors. Standards Application Approx. 3545 lbs per 1,000 sf or 1,500 - 2,000 lbs per acre Hydromulch Rates Shall be applied with hydromulcher. Shall not be used without seed and Remarks tackifier unless the application rate is at least doubled. Fibers longer than about 3/4 -1 inch clog hydromulch equipment. Fibers should be kept to less than 3/4 inch. Quality No visible water or dust during handling. Must be produced per WAC 173 - Standards 350, Solid Waste Handling Standards, but may have up to 35% biosolids. Application 2" thick min.; approx. 100 tons per acre (approx. 750 lbs per cubic yard) Rates More effective control can be obtained by increasing thickness to 3". Excel - Compost lent mulch for protecting final grades until landscaping because it can be dir- ectly seeded or tilled into soil as an amendment. Compost used for mulch Remarks has a coarser size gradation than compost used for BMP C125: Topsoiling / Composting or BMP T5.13: Post -Construction Soil Quality and Depth. It is more stable and practical to use in wet areas and during rainy weather conditions. Do not use near wetlands or near phosphorous impaired water bodies. Quality Gradations from fines to 6 inches in length for texture, variation, and inter - Chipped Standards locking properties. Include a mix of various sizes so that the average size Site Veget- is between 2- and 4- inches. ation Application 2" thick min.; Rates 2019 Stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 291 Table II -3.6: Mulch Standards and Guidelines (continued) Mulch Mater- Guideline Description ial This is a cost-effective way to dispose of debris from clearing and grub- bing, and it eliminates the problems associated with burning. Generally, it should not be used on slopes above approx. 10% because of its tendency to be transported by runoff. It is not recommended within 200 feet of sur - Remarks face waters. If permanent seeding or planting is expected shortly after mulch, the decomposition of the chipped vegetation may tie up nutrients important to grass establishment. Note: thick application of this material over existing grass, herbaceous spe- cies, and some groundcovers could smother and kill vegetation. No visible water or dust during handling. Must be purchased from a supplier Quality with a Solid Waste Handling Permit or one exempt from solid waste reg- Standards ulations. Application 2" thick min.; approx. 100 tons per acre (approx. 750 lbs. per cubic yard) Wood- Rates Based This material is often called "wood straw" or "hog fuel'. The use of mulch Mulch ultimately improves the organic matter in the soil. Special caution is advised regarding the source and composition of wood -based mulches. Its Remarks preparation typically does not provide any weed seed control, so evidence of residual vegetation in its composition or known inclusion of weed plants or seeds should be monitored and prevented (or minimized). Quality A blend of loose, long, thin wood pieces derived from native conifer or Standards deciduous trees with high length -to -width ratio. Application Rates 2" thick min. WOOd Cost-effective protection when applied with adequate thickness. A min - Strand imum of 95 -percent of the wood strand shall have lengths between 2 and Mulch 10 -inches, with a width and thickness between 1/16 and 1/2 -inches. The Remarks mulch shall not contain resin, tannin, or other compounds in quantities that would be detrimental to plant life. Sawdust or wood shavings shall not be used as mulch. [Specification 9-14.4(4) from the Standard Specifications for Road, Bridge, and Municipal Construction(WSDOT, 2016) BMP C122: Nets and Blankets Purpose Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place on steep slopes and in channels so that vegetation can become well established. In addition, some nets and blankets can be used to permanently reinforce turf to protect drainage ways during high flows. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 292 Nets (commonly called matting) are strands of material woven into an open, but high -tensile strength net (for example, coconut fiber matting). Blankets are strands of material that are not tightly woven, but instead form a layer of interlocking fibers, typically held together by a biodegradable or pho- todegradable netting (for example, excelsior or straw blankets). They generally have lower tensile strength than nets, but cover the ground more completely. Coir (coconut fiber) fabric comes as both nets and blankets. Conditions of Use Erosion control netting and blankets shall be made of natural plant fibers unaltered by synthetic materials. Erosion control nets and blankets should be used: . To aid permanent vegetated stabilization of slopes 2H:1 V or greater and with more than 10 feet of vertical relief. . For drainage ditches and swales (highly recommended). The application of appropriate net- ting or blanket to drainage ditches and swales can protect bare soil from channelized runoff while vegetation is established. Nets and blankets also can capture a great deal of sediment due to their open, porous structure. Nets and blankets can be used to permanently stabilize channels and may provide a cost-effective, environmentally preferable alternative to riprap. Disadvantages of nets and blankets include: . Surface preparation is required. . On slopes steeper than 2.5H:1 V, net and blanket installers may need to be roped and har- nessed for safety. . They cost at least $4,000-6,000 per acre installed. Advantages of nets and blankets include: . Installation without mobilizing special equipment. . Installation by anyone with minimal training . Installation in stages or phases as the project progresses. . Installers can hand place seed and fertilizer as they progress down the slope. . Installation in any weather. . There are numerous types of nets and blankets that can be designed with various parameters in mind. Those parameters include: fiber blend, mesh strength, longevity, biodegradability, cost, and availability. An alternative to nets and blankets in some limited conditions is BMP C202: Riprap Channel Lining. Ensure that BMP C202: Riprap Channel Lining is appropriate before using it as a substitute for nets and blankets. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 293 Design and Installation Specifications . See Figure II -3.3: Channel Installation (Clackamas County et al., 2008) and Figure Slope Installation for typical orientation and installation of nets and blankets used in channels and as slope protection. Note: these are typical only; all nets and blankets must be installed per manufacturer's installation instructions. . Installation is critical to the effectiveness of these products. If good ground contact is not achieved, runoff can concentrate under the product, resulting in significant erosion. . Installation of nets and blankets on slopes: 1. Complete final grade and track walk up and down the slope. 2. Install hydromulch with seed and fertilizer. 3. Dig a small trench, approximately 12 inches wide by 6 inches deep along the top of the slope. 4. Install the leading edge of the net/blanket into the small trench and staple approximately every 18 inches. NOTE: Staples are metal, "U" -shaped, and a minimum of 6 inches long. Longer staples are used in sandy soils. Biodegradable stakes are also available. 5. Roll the net/blanket slowly down the slope as the installer walks backward. N OTE: The net/blanket rests against the installer's legs. Staples are installed as the net/blanket is unrolled. It is critical that the proper staple pattern is used for the net/blanket being installed. The net/blanket is not to be allowed to roll down the slope on its own as this stretches the net/blanket, making it impossible to maintain soil contact. In addition, no one is allowed to walk on the net/blanket after it is in place. 6. If the net/blanket is not long enough to cover the entire slope length, the trailing edge of the upper net/blanket should overlap the leading edge of the lower net/blanket and be stapled. On steeper slopes, this overlap should be installed in a small trench, stapled, and covered with soil. . With the variety of products available, it is impossible to cover all the details of appropriate use and installation. Therefore, it is critical that the designer consult the manufacturer's inform- ation and that a site visit takes place in order to ensure that the product specified is appro- priate. Information is also available in WSDOT's Standard Specifications for Road, Bridge, and Municipal Construction Division 8-01 and Division 9-14 (WSDOT, 2016). Use jute matting in conjunction with mulch (BMP C121: Mulching). Excelsior, woven straw blankets and coir (coconut fiber) blankets may be installed without mulch. There are many other types of erosion control nets and blankets on the market that may be appropriate in cer- tain circumstances. . In general, most nets (e.g., jute matting) require mulch in order to prevent erosion because they have a fairly open structure. Blankets typically do not require mulch because they usually provide complete protection of the surface. . Extremely steep, unstable, wet, or rocky slopes are often appropriate candidates for use of synthetic blankets, as are riverbanks, beaches and other high-energy environments. If 2019 Stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 294 synthetic blankets are used, the soil should be hydromulched first. I vu -percent biodegradable blankets are available for use in sensitive areas. These organic blankets are usually held together with a paper or fiber mesh and stitching which may last up to a year. . Most netting used with blankets is photodegradable5 meaning it breaks down under sunlight (not UV stabilized). However, this process can take months or years even under bright sun. Once vegetation is established, sunlight does not reach the mesh. It is not uncommon to find non -degraded netting still in place several years after installation. This can be a problem if maintenance requires the use of mowers or ditch cleaning equipment. In addition, birds and small animals can become trapped in the netting. Maintenance Standards . Maintain good contact with the ground. Erosion must not occur beneath the net or blanket. . Repair and staple any areas of the net or blanket that are damaged or not in close contact with the ground. . Fix and protect eroded areas if erosion occurs due to poorly controlled drainage. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 295 Figure II -3.3: Channel Installation 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 296 NOT TO SCALE . • i t `1,�w l Vr \/j / \ 80\/// LONGITUDINAL ANCHOR TRENCH TERMINAL SLOPE AND CHANNEL ANCHOR TRENCH P 16 STAKE AT 3 r-5' INTERVALS P P s> P. r R WV :...1 ..;= � 44 GOp O� $ P P P P / CHECK SLOT AT 25' INTERVALS ISOMETRIC VIEW P P P s• �f- 12 \\\\\\\ \CrI\ \\ \\\\\\\\\\\\\\\ \\ \\ \\\ INITIAL CHANNEL ANCHOR TRENCH INTERMITTVENT CHECK SLOT Notes: 1. Check slots to be constructed per manufacturers specifications. (Clackamas County et al., 2008) 2. Staking or stapling layout per manufacturers specifications. Channel Installation Revised July 2016 DEPARTMENT OF ECOLOGY Please see http:dwww.ecy,wa.gov/copyr/ght.html for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 296 Figure IImaAm. Slope Installation 2019 Stormwater Management Manual for Western Washington Volume 11 - Chapfer 3 -Page 297 Anchor in 6" x 6" min. trench and staple at 12" intervals Se ME MEMO PA We DOW ED SEE :o.' M r :� �. <v 4^.1q %• k?''S i. Y' ,L.4�V•0L Min. 2" overlap k as'"YM'`r*iw' overlap art* es a •. •S `9 tJ.L er.'s;vmw ••.. �. Na IL 55 0414 40 D74" ,!,* •t a • ••'ME Staple overlaps max. 5" spacing Bring material down to a level area, turn the end under 4" and staple at 12" intervals Notes: 1. Slope surface shall be smooth before placement for proper soil contact, 2. Stapling pattern as per manufacturers recommendations. 3. Do not stretch blankets/mattings tight - allow the rolls to mold to any irregularities. 4. For slopes less than 3H:1V, rolls may be placed in horizontal strips. 5. if there is a berm at the top of the slope, anchor upslope of the berm. 6. Lime, fertilize, and seed before installation. Planting of shrubs, trees, etc, should occur after installation. NOT TO SCALE Slope Installation Revised June 2016 DEPARTMENT OF ECOLOGY Please see http:llwww.ecywa.govlcopyilghthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 - Chapfer 3 -Page 297 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Use Plastic covering maybe used on disturbed areas that require cover measures for less than 30 days, except as stated below. . Plastic is particularly useful for protecting cut and fill slopes and stockpiles. However, the rel- atively rapid breakdown of most polyethylene sheeting makes it unsuitable for applications greater than six months. . Due to rapid runoff caused by plastic covering, do not use this method upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes. Plastic sheeting may result in increased runoff volumes and velocities, requiring additional on- site measures to counteract the increases. Creating a trough with wattles or other material can convey clean water away from these areas. . To prevent undercutting, trench and backfill rolled plastic covering products. . Although the plastic material is inexpensive to purchase, the cost of installation, maintenance, removal, and disposal add to the total costs of this BMP. . Whenever plastic is used to protect slopes, install water collection measures at the base of the slope. These measures include plastic -covered berms, channels, and pipes used to convey clean rainwater away from bare soil and disturbed areas. Do not mix clean runoff from a plastic covered slope with dirty runoff from a project. . Other uses for plastic include: o Temporary ditch liner. Pond liner in temporary sediment pond. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored. o Emergency slope protection during heavy rains. Temporary drainpipe ("elephant trunk") used to direct water. Design and Installation Specifications . Plastic slope cover must be installed as follows: 1. Run plastic up and down the slope, not across the slope. 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 298 3. Provide a minimum of 8 -inch overlap at the seams. 4. On long or wide slopes, or slopes subject to wind, tape all seams. 5. Place plastic into a small (12 -inch wide by 6 -inch deep) slot trench at the top of the slope and backfill with soil to keep water from flowing underneath. 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and tie them together with twine to hold them in place. 7. Inspect plasticfor rips, tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil, which causes extreme erosion. 8. Sandbags maybe lowered into place tied to ropes. However, all sandbags must be staked in place. . Plastic sheeting shall have a minimum thickness of 0.06 millimeters. . If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance Standards . Torn sheets must be replaced and open seams repaired. . Completely remove and replace the plastic if it begins to deteriorate due to ultraviolet radi- ation. . Completely remove plastic when no longer needed. . Dispose of old tires used to weight down plastic sheeting appropriately. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not pass through the Technology Assessment Protocol —Ecology (TAPE) process. Local jurisdictions may choose not to accept these products, or may require additional testing prior to consideration for local use. Products that Ecology has approved as functionally equivalent are available for review on Ecology's website at: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C124: Sodding Purpose The purpose of sodding is to establish turf for immediate erosion protection and to stabilize drainage paths where concentrated overland flow will occur. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 299 Conditions of Use Sodding maybe used in the following areas: . Disturbed areas that require short-term or long-term cover. . Disturbed areas that require immediate vegetative cover. . All waterways that require vegetative lining. Waterways may also be seeded rather than sod- ded, and protected with a net or blanket. Design and Installation Specifications Sod shall be free ofweeds, of uniform thickness (approximately 1 -inch thick), and shall have a dense root mat for mechanical strength. The following steps are recommended for sod installation: 1. Shape and smooth the surface to final grade in accordance with the approved grading plan. Consider any areas (such as swales) that need to be overexcavated below design elevation to allow room for placing soil amendment and sod. 2. Amend 4 inches (minimum) of compost into the top 8 inches of the soil if the organic content of the soil is less than ten percent or the permeability is less than 0.6 inches per hour. See https:Hecology.wa.gov/Waste-Toxics/Reducing-recycling-waste/Organic-mater- ials/Managing-organics-compost for further information. 3. Fertilize according to the sod supplier's recommendations. 4. Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface. 5. Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a close, tight fit. Staggerjoints at least 12 inches. Staple on slopes steeper than 3H:1 V. Staple the upstream edge of each sod strip. 6. Roll the sodded area and irrigate. 7. When sodding is carried out in alternating strips or other patterns, seed the areas between the sod immediately after sodding. Maintenance Standards If the grass is unhealthy, the cause shall be determined and appropriate action taken to reestablish a healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation, instability, or some other cause, the sod shall be removed, the area seeded with an appropriate mix, and protected with a net or blanket. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 300 BMP C125: Topsoiling / Composting Purpose Topsoiling and composting provide a suitable growth medium for final site stabilization with veget- ation. While not a permanent cover practice in itself, topsoiling and composting are an integral com- ponent of providing permanent cover in those areas where there is an unsuitable soil surface for plant growth. Use this BMP in conjunction with other BMPs such as BMP C120: Temporary and Per- manent Seeding, BMP C121: Mulching, or BMP C124: Sodding. Implementation of this BMP may meet the post -construction requirements of BMP T5.13: Post -Construction Soil Quality and Depth. Native soils and disturbed soils that have been organically amended not only retain much more stormwater, but also serve as effective biofilters for urban pollutants and, by supporting more vig- orous plant growth, reduce the water, fertilizer and pesticides needed to support installed land- scapes. Topsoil does not include any subsoils but only the material from the top several inches including organic debris. Conditions of Use . Permanent landscaped areas shall contain healthy topsoil that reduces the need for fertilizers, improves overall topsoil quality, provides for better vegetative health and vitality, improves hydrologic characteristics, and reduces the need for irrigation. . Leave native soils and the duff layer undisturbed to the maximum extent practicable. Stripping OT existing, properlyfunctioning soil system and vegetation for the purpose of topsoiling during construction is not acceptable. Preserve existing soil systems in undisturbed and uncom- pacted conditions if functioning properly. . Areas that already have good topsoil, such as undisturbed areas, do not require soil amend- ments. Restore, to the maximum extent practical, native soils disturbed during clearing and grading to a condition equal to or better than the original site conon's moisture -holding capacity. Use on-site native topsoil, incorporate amendments into on-site soil, or import blended topsoil to meet this requirement. . Topsoiling is a required procedure when establishing vegetation on shallow soils, and soils of critically low pH (high acid) levels. . Beware of where the topsoil comes from, and what vegetation was on site before disturbance. Invasive plant seeds maybe included and could cause problems for establishing native plants, landscaped areas, or grasses. . Topsoil from the site will contain mycorrhiza) bacteria that are necessary for healthy root growth and nutrient transfer. These native mycorrhiza are acclimated to the site and will provide optimum conditions for establishing grasses. Use commercially available mycorrhiza products when using off-site topsoil. 2019 Sformwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 301 Design and Installation Specifications Meet the following requirements for disturbed areas that will be developed as lawn or landscaped areas at the completed project site: . Maximize the depth of the topsoil wherever possible to provide the maximum possible infilt- ration capacity and beneficial growth medium. Topsoil shall have: A minimum depth of 8- inches. Scarify subsoils below the topsoil layer at least 4 -inches with some incorporation of the upper material to avoid stratified layers, where feasible. Ripping or re -structuring the subgrade may also provide additional benefits regarding the overall infiltration and interflow dynamics of the soil system. ° A minimum organic content of 10%dry weight in planting beds, and 5%organic matter content in turf areas. Incorporate organic amendments to a minimum 8 -inch depth except where tree roots or other natural features limit the depth of incorporation. ° A pH between 6.0 and 8.0 or matching the pH of the undisturbed soil. ° If blended topsoil is imported, then fines should be limited to 25 percent passing through a 200 sieve. . Mulch planting beds with 2 inches of organic material . Accomplish the required organic content, depth, and pH by returning native topsoil to the site, importing topsoil of sufficient organic content, and/or incorporating organic amendments. When using the option of incorporating amendments to meet the organic content requirement, use compost that meets the compost specification for Bioretention (See BMP T7.30: Biore- tention), with the exception that the compost may have up to 35% biosolids or manure. . Sections 3 through 7 of Building Soil: Guidelines and Resources for Implementing Soil Quality and Depth BMP T5.13 in WDOE Stormwater Management Manual for Western Washington (Stenn et al., 2016), provides useful guidance for implementing whichever option is chosen. It includes guidance for pre -approved default strategies and guidance for custom strategies. Check with your local jurisdiction concerning its acceptance of this guidance. . The final composition and construction of the soil system will result in a natural selection or favoring of certain plant species over time. For example, incorporation of topsoil may favor grasses, while layering with mildly acidic, high -carbon amendments may favor more woody vegetation. . Allow sufficient time in scheduling for topsoil spreading prior to seeding, sodding, or planting. . Take care when applying top soil to subsoils with contrasting textures. Sandy topsoil over clayey subsoil is a particularly poor combination, as water creeps along the junction between the soil layers and causes the topsoil to slough. If topsoil and subsoil are not properly bonded, water will not infiltrate the soil profile evenly and it will be difficult to establish vegetation. The best method to promote bonding is to actually work the topsoil into the layer below for a depth of at least 6 inches. . Field exploration of the site shall be made to determine if there is surface soil of sufficient quantity and quality to justify stripping. Topsoil shall be friable and loamy (loam, sandy loam, 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 302 silt loam, sandy clay loam, and clay loam). Avoid areas of natural ground water recharge. Stripping shall be confined to the immediate construction area. A 4 -inch to 6 -inch stripping depth is common, but depth may vary depending on the particular soil. All surface runoff con- trol structures shall be in place prior to stripping. . Do not place topsoil while in a frozen or muddy condition, when the subgrade is excessively wet, or when conditions exist that may otherwise be detrimental to proper grading or pro- posed sodding or seeding. . In any areas requiring grading, remove and stockpile the duff layer and topsoil on site in a des- ignated, controlled area, not adjacent to public resources and critical areas. Reapply stock- piled topsoil to other portions of the site where feasible. . Locate the topsoil stockpile so that it meets specifications and does not interfere with work on the site. It may be possible to locate more than one pile in proximity to areas where topsoil will be used. . Stockpiling of topsoil shall occur in the following manner: Side slopes of the stockpile shall not exceed 2H:1 V. Between October 1 and April 30: ■ An interceptor dike with gravel outlet and silt fence shall surround all topsoil. ■ Within 2 days complete erosion control seeding, or covering stockpiles with clear plastic, or other mulching materials. Between May 1 and September 30: ■ An interceptor dike with gravel outlet and silt fence shall surround all topsoil if the stockpile will remain in place for a longer period of time than active construction grading. ■ Within 7 days complete erosion control seeding, or covering stockpiles with clear plastic, or other mulching materials. . When native topsoil is to be stockpiled and reused the following should apply to ensure that the mycorrhizal bacterial, earthworms, and other beneficial organisms will not be destroyed: o Re -install topsoil within 4 to 6 weeks. o Do not allow the saturation of topsoil with water. Do not use plastic covering. Maintenance Standards . Inspect stockpiles regularly, especially after large storm events. Stabilize any areas that have eroded. . Establish soil quality and depth toward the end of construction and once established, protect from compaction, such as from large machinery use, and from erosion. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 303 Plant and mulch soil after installation. Leave plant debris or its equivalent on the soil surface to replenish organic matter. . Reduce and adjust, where possible, the use of irrigation, fertilizers, herbicides and pesticides, rather than continuing to implement formerly established practices. BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection Purpose Polyacrylamide (PAM) is used on construction sites to prevent soil erosion. Applying PAM to bare soil in advance of a rain event significantly reduces erosion and controls sed- iment in two ways. First, PAM increases the soil's available pore volume, thus increasing infiltration and reducing the quantity of stormwater runoff. Second, it increases flocculation of suspended particles and aids in their deposition, thus reducing stormwater runoff turbidity and improving water quality. Conditions of Use PAM shall not be directly applied to water or allowed to enter a water body. Stormwater runoff shall pass through a sediment pond prior to discharging to surface waters. PAM can be applied to bare soil under the following conditions: . During rough grading operations. . In Staging areas. . Balanced cut and fill earthwork. . Haul roads prior to placement of crushed rock surfacing. . Compacted soil roadbase. . Stockpiles. After final . grade and before paving orfinal seeding and planting. . Pit sites. . Sites having a winter shut down. In the case of winter shut down, or where soil will remain unworked for several months, PAM should be used together with mulch. Design and Installation Specifications . Do not use PAM on a slope that flows directly into as or wetland. . Do not add PAM to water discharging from the site. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 304 . PAM designated for these uses should be "water soluble" or "linear" or "non-crosslinked". Cross-linked or water absorbent PAM, polymerized in highly acidic (pH<2) conditions, are used to maintain soil moisture content. . The PAM anionic charge density may vary from 2-30 percent; a value of 18 percent is typical. Studies conducted by the United States Department of Agriculture (USDA)/ARS demon- strated that soil stabilization was optimized by using very high molecular weight (12-15 mg/ - mole), highly anionic (>20% hydrolysis) PAM. PAM tackifiers are available and being used in place of guar and alpha plantago. Typically, PAM tackifiers should be used at a mixing rate of no more than 0.5-1 Ib. per 1000 gallons of water in a hydromulch machine. Some tackifier product instructions say to use at an applic- ation rate of 3 — 5 lbs per acre, which can be too much. In addition, pump problems can occur at higher application rates due to increased viscosity. Maintenance Standards . PAM maybe reapplied on actively worked areas after a 48-hour period. . Reapplication is not required unless PAM treated soil is disturbed or unless turbidity levels show the need for an additional application. If PAM treated soil is left undisturbed, a reapplic- ation may be necessary after two months. More PAM applications may be required for steep slopes, silty and clayey soils (USDA Classification Type "C" and "D" soils), long grades, and high precipitation areas. When PAM is applied first to bare soil and then covered with straw, a reapplication may not be necessary for several months. . Loss of sediment and PAM may be a basis for penalties per RCW 90.48.080. . PAM may affect the treatment efficiency of chitosan flocculent systems. BMP C130: Surface Roughening Purpose Surface roughening aids in the establishment of vegetative cover, reduces runoff velocity, increases infiltration, and provides for sediment trapping through the provision of a rough soil surface. Hori- zontal depressions are created by operating a tiller or other suitable equipment on the contour or by leaving slopes in a roughened condition by not fine grading them. Use this BMP in conjunction with other BMPs such as BMP C120: Temporary and Permanent Seed- ing, BMP C121: Mulching, or BMP C124: Sodding. Conditions for Use . All slopes steeper than 3H:1 V and greater than 5 vertical feet require surface roughening to a depth of 2 to 4 inches prior to seeding. . Areas that will not be stabilized immediately maybe roughened to reduce runoff velocity until seeding takes place. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 307 Slopes with a stable rock face do not require roughening. . Slopes where mowing is planned should not be excessively roughened. Design and Installation Specifications There are different methods for achieving a roughened soil surface on a slope, and the selection of an appropriate method depends upon the type of slope. Roughening methods include stair -step grading, grooving, contour furrows, and tracking. See Figure II -3.5: Surface Roughening by Track - and Contour Furrows. Factors to be considered in choosing a roughening method are slope steepness, mowing requirements, and whether the slope is formed by cutting or filling. . Disturbed areas that will not require mowing maybe stair -step graded, grooved, or left rough after filling. . Stair -step grading is particularly appropriate in soils containing large amounts of soft rock. Each "step" catches material that sloughs from above, and provides a level site where veget- ation can become established. Stairs should be wide enough to work with standard earth mov- ing equipment. Stair steps must be on contour or gullies will form on the slope. . Areas that will be mowed (these areas should have slopes less steep than 3H:1 V) may have small furrows left by disking, harrowing, raking, or seed -planting machinery operated on the contour. . Graded areas with slopes steeper than 3H:1 V but less than 2H:1 V should be roughened before seeding. This can be accomplished in a variety of ways, including "trackwalking," or driving a crawler tractor up and down the slope, leaving a pattern of cleat imprints parallel to slope contours. . Tracking is done by operating equipment up and down the slope to leave horizontal depres- sions inthe soil. Maintenance Standards . Areas that are surface roughened should be seeded as quickly as possible. . Regular inspections should be made of the area. If rills appear, they should be re -roughened and re -seeded immediately. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 308 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 309 mom • UN 11=i. 1=11=11=L 11=11.11:11:11:1 �, u. 11=11 ��i-11=11=, r.11-11-11-11-11- � 11=11=II=.11:=11=11= . 11-11-11'11 Ph ' f.11a1:11a1. 1=11=11=11-11= -11:11= 11=11=1i- .11, 66;116" 1-.. .11=11-11-1i- 11=11=1tr 1=11-11=11- . 11=11-11-11-i� 11=11=II=11-.. d=11=11=II-11=11 -11-11=11=11=d=11=11=11=11 = —11=11=JI=11=11=11 • • =11=of 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 309 BMP CUM Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage ways, and surface waters. Conditions of Use Use dust control in areas (including roadways) subject to surface and air movement of dustwhere on-site or off-site impacts to roadways, drainage ways, or surface waters are likely. Design and Installation Specifications . Vegetate or mulch areas that will not receive vehicle traffic. In areas where planting, mulching, or paving is impractical, apply gravel or landscaping rock. . Limit dust generation by clearing only those areas where immediate activity will take place, leaving the remaining area(s) in the original condition. Maintain the original ground cover as long as practical. . Construct natural or artificial windbreaks or windscreens. These may be designed as enclos- ures for small dust sources. . Sprinkle the site with water until the surface is wet. Repeat as needed. To prevent carryout of mud onto the street, refer to BMP C105: Stabilized Construction Access and BMP C106: Wheel Wash. . Irrigation water can be used for dust control. Irrigation systems should be installed as a first steF; on sites where dust control is a concern. . Spray exposed soil areas with a dust palliative, following the manufacturer's instructions and cautions regarding handling and application. Used oil is prohibited from use as a dust sup- pressant. Local governments may approve other dust palliatives such as calcium chloride or PAM. . PAM (BMP C126: Polyacrylamide (PAM) for Soil Erosion Protection) added to water at a rate of 0.5 pounds per 1,000 gallons of water per acre and applied from a water truck is more effect- ive than water alone. This is due to increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily trans- ported by wind. Adding PAM may reduce the quantity of water needed for dust control. Note that the application rate specified here applies to this BMP, and is not the same application rate that is specified in BMP C1 26: Polyacrylamide (PAM) for Soil Erosion Protection, but the downstream protections still apply. Refer to BMP C1 26: Polyacry lamide (PAM) for Soil Erosion Protection for conditions of use. PAM shall not be directly applied to water or allowed to enter a water body. . Contact your local Air Pollution Control Authority for guidance and training on other dust con- trol measures. Compliance with the local Air Pollution Control Authority constitutes 2019 Sformwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 313 compliance with this BMP Use vacuum street sweepers. . Remove mud and other dirt promptly YOU it does not dry and then turn into dust. . Techniques that can be used for unpaved roads and lots include: Lower speed limits. H igh vehicle speed increases the amount of dust stirred up from unpaved roads and lots. Upgrade the road surface strength by improving particle size, shape, and mineral types that make up the surface and base materials. Add surface gravel to reduce the source of dust emission. Limit the amount of fine particles (those smaller than .075 mm) to 10 to 20 percent. Use geotextile fabrics to increase the strength of new roads or roads undergoing recon- struction. o Encourage the use of alternate, paved routes, if available. o Apply chemical dust suppressants using the admix method, blending the product with the top few inches of surface material. Suppressants may also be applied as surface treatments. o Limit dust -causing work on windy days. o Pave unpaved permanent roads and other trafficked areas. Maintenance Standards Respray area as necessary to keep dust to a minimum. BMP C150: Materials on Hand Purpose Keep quantities of erosion prevention and sediment control materials on the project site at all times to be used for regular maintenance and emergency situations such as unexpected heavy rains. Hav- ing these materials on-site reduces the time needed to replace existing or implement new BMPs when inspections indicate that existing BMPs are not meeting the Construction SWPPP require- ments. In addition, contractors can save money by buying some materials in bulk and storing them at their office or yard. Conditions of Use . Construction projects of any size or type can benefit from having materials on hand. A small commercial development project could have a roll of plastic and some gravel available for immediate protection of bare soil and temporary berm construction. A large earthwork project, such as highway construction, might have several tons of straw, several rolls of plastic, flexible 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 314 pipe, sandbags, geotextile fabric and steel " I posts. . Materials should be stockpiled and readily available before any site clearing, grubbing, or earthwork begins. A large contractor or project proponent could keep a stockpile of materials that are available for use on several projects. . If storage space at the project site is at a premium, the contractor could maintain the materials at their office or yard. The office or yard must be less than an hour from the project site. Design and Installation Specifications Depending on project type, size, complexity, and length, materials and quantities will vary. A good minimum list of items that will cover numerous situations includes: . Clear Plastic, 6 mil . Drainpipe, 6 or 8 inch diameter . Sandbags, filled . Straw Bales for mulching . Quarry Spalls . Washed Gravel . Geotextile Fabric . Catch Basin Inserts . Steel "T" Posts . Silt fence material . Straw Wattles Maintenance Standards . All materials with the exception of the quarry spalls, steel "T" posts, and gravel should be kept covered and out of both sun and rain. Re -stock materials as needed. BMP C151: Concrete Handling Concrete work can generate process water and slurry that contain fine particles and high pH, both of which can violate water quality standards in the receiving water. Concrete spillage or concrete charge to waters of the State is prohibited. Use this BMP to minimize and eliminate concrete, con- crete process water, and concrete slurry from entering waters of the State. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 315 Conditions of Use Any time concrete is used, utilize these management practices. Concrete construction project com- ponents include, but are not limited to: . Curbs . Sidewalks Roads . Bridges . Foundations . Floors . Runways Disposal options for concrete, in order of preference are: 1. Off-site disposal 2. Concrete wash-out areas (see BMP C154: Concrete Washout Area) 3. De minimus washout to formed areas awaiting concrete Design and Installation Specifications . Wash concrete truck drums at an approved off-site location or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground (including formed areas awaiting concrete), or into storm drains, open ditches, streets, or streams. Refer to BMP C154: Concrete Washout Area for information on concrete washout areas. Return unused concrete remaining in the truck and pump to the originating batch plant for recycling. Do not dump excess concrete on site, except in designated concrete washout areas as allowed in BMP C154: Concrete Washout Area. . Wash small concrete handling equipment (e.g. hand tools, screeds, shovels, rakes, floats, trowels, and wheelbarrows) into designated concrete washout areas or into formed areas awaiting concrete pour. . At no time shall concrete be washed off into the footprint of an area where an infiltration fea- ture will be installed. . Wash equipment difficult to move, such as concrete paving machines, in areas that do not ectlydrain tonatural orconstructed stormwater conveyance or potential infiltration areas. . Do not allow washwater from areas, such as concrete aggregate driveways, to drain directly (without detention or treatment) to natural or constructed stormwater conveyances. . Contain washwater and leftover product in a lined container when no designated concrete washout areas (or formed areas, allowed as described above) are available. Dispose of con- tained concrete and concrete washwater (process water) properly. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 316 . Always use forms or solid barriers for concrete pours, such as pilings, within 15 -feet of surface waters. . Refer to BMP C252: Treating and Disposing of High pH Watqui for pH adjustment require- ments. Refer to the Construction Stormwater General Permit (CSWGP) for pH monitoring require- ments if the project involves one of the following activities: Significant concrete work (as defined in the CSWGP). o The use of soils amended with (but not limited to) Portland cement -treated base, cement kiln dust or fly ash. Discharging stormwater to segments of water bodies on the 303(d) list (Category 5) for high pH. Maintenance Standards Check containers for holes in the liner daily during concrete pours and repair the same day. BMP C152: Sawcutting and Surfacing Pollution Prevention Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high pH (concrete cutting), both of which can violate the water quality standards in the receiving water. Concrete spillage or concrete discharge to waters of the State is prohibited. Use this BMP to minimize and eliminate process water and slurry created through sawcutting or surfacing from enter- ing waters of the State. Conditions of Use Utilize these management practices anytime sawcutting or surfacing operations take place. Saw - cutting and surfacing operations include, but are not limited to: . Sawing . Coring . Grinding . Roughening . Hydro-demoon . Bridge and road surfacing 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 317 Design and Installation Specifications . Vacuum slurry and cuttings during cutting and surfacing operations. . Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight. . Slurry and cuttings shall not drain to any natural or constructed drainage conveyance includ- ing stormwater systems. This may require temporarily blocking catch basins. Dispose of collected slurry and cuttings in a manner that does not violate ground water or sur- face water quality standards. . Do not allow process water generated during hydro -demolition, surface roughening or similar operations to drain to any natural or constructed drainage conveyance including stormwater systems. Dispose of process water in a manner that does not violate ground water or surface water quality standards. . Handle and dispose of cleaning waste material and demolition debris in a manner that does not cause contamination of water. Dispose of sweeping material from a pick-up sweeper at an appropriate disposal site. Maintenance Standards Continually monitor operations to determine whether slurry, cuttings, or process water could enter waters of the state. If inspections show that a violation of water quality standards could occur, stop operations and immediately implement preventive measures such as berms, barriers, secondary containment, and/or vacuum trucks. BMP C153: Material Delivery, Storage, and Containment Purpose Prevent, reduce, or eliminate the discharge of pollutants to the stormwater system or watercourses from material delivery and storage. Minimize the storage of hazardous materials on-site, store mater- ials in a designated area, and install secondary containment. Conditions of Use Use at construction sites with delivery and storage of the following materials: . Petroleum products such as fuel, oil and grease . Soil stabilizers and binders (e.g., Polyacrylamide) . Fertzers, pesticides and herbicides . Detergents . Asphalt and concrete compounds 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 318 . Hazardous chemicals such as acids, lime, adhesives, paints, solvents, and curing compounds . Any other material that may be detrimental if released to the environment Design and Installation Specifications . The temporary storage area should be located away from vehicular traffic, near the con- struction entrance(s), and away from waterways or storm drains. . Safety Data Sheets (SDS) should be supplied for all materials stored. Chemicals should be kept in their original labeled containers. Hazardous material storage on-site should be minimized. . Hazardous materials should be handled as infrequently as possible. . During the wet weather season (Oct 1 — April 30), consider storing materials in a covered area. . Materials should be stored in secondary containments, such as an earthen dike, horse trough, or even a children's wading pool for non-reactive materials such as detergents, oil, grease, and paints. Small amounts of material may be secondarily contained in "bus boy" trays or con- crete mixing trays. Do not store chemicals, drums, or bagged materials directly on the ground. Place these items on a pallet and, when possible, within secondary containment. . If drums must be kept uncovered, store them at a slight angle to reduce ponding of rainwater on the lids to reduce corrosion. Domed plastic covers are inexpensive and snap to the top of drums, preventing water from collecting. . Liquids, petroleum products, and substances listed in 40 CFR Parts 110, 117, or 302 shall be stored in approved containers and drums and shall not be overfilled. Containers and drums shall be stored in temporary secondary containment facilities. . Temporary secondary containment facilities shall provide for a spill containment volume able to contain 10% of the total enclosed container volume of all containers, or 110% of the capa- city of the largest container within its boundary, whichever is greater. . Secondary containment facilities shall be impervious to the materials stored therein for a min- imum contact time of 72 hours. . Sufficient separation should be provided between stored containers to allow for spill cleanup and emergency response access. . During the wet weather season (Oct 1 — April 30), each secondary containment facility shall be covered during non -working days, prior to and during rain events. Keep material storage areas clean, organized and equipped with an ample supply of appro- priate spill clean-up material (spill kit). . The spill kit should include, at a minimum: 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 319 I -Water Resistant Nylon Bag 3 -Oil Absorbent Socks 3"x 4' 2 -Oil Absorbent Socks 3"x 10' 12 -Oil Absorbent Pads 17"x19" 0 1 -Pair Splash Resistant Goggles 0 3 -Pair Nitrile Gloves 10 -Disposable Bags with Ties Instructions Maintenance Standards . Secondary containment facilities shall be maintained free of accumulated rainwater and spills. In the event of spills or leaks, accumulated rainwater and spills shall be collected and placed into drums. These liquids shall be handled as hazardous waste unless testing determines them to be non -hazardous. . Re -stock spill kit materials as needed. BMP C154: Concrete Washout Area Purpose Prevent or reduce the discharge of pollutants from concrete waste to stormwater by conducting washout off-site, or performing on-site washout in a designated area. Conditions of Use Concrete washout areas are implemented on construction projects where: . Concrete is used as a construction material . Itis not possible to dispose of all concrete wastewater and washout off-site (ready mix plant, etc.). . Concrete truck drums are washed on-site. Note that auxiliary concrete truck components (e.g. chutes and hoses) and small concrete handling equipment (e.g. hand tools, screeds, shovels, rakes, floats, trowels, and wheel- barrows) may be washed into formed areas awaiting concrete pour. At no time shall concrete be washed off into the footprint of an area where an infiltration feature will be installed. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 320 Design and Installation Specifications Implementation . Perform washout of concrete truck drums at an approved off-site location or in designated con - Crete washout areas only. . Do not wash out concrete onto non -formed areas, or into storm drains, open ditches, streets, or streams. . Wash equipment difficult to move, such as concrete paving machines, in areas that do not ectly drain to natural or constructed stormwater conveyance or potential infiltration areas. . Do not allow excess concrete to be dumped on-site, except in designated concrete washout areas as allowed above. . Concrete washout areas maybe prefabricated concrete washout containers, orself-installed structures (above -grade or below -grade). Prefabricated containers are most resistant to damage and protect against spills and leaks. Companies may offer delivery service and provide regular maintenance and disposal of solid and liquid waste. . If self -installed concrete washout areas are used, below -grade structures are preferred over above -grade structures because they are less prone to spills and leaks. . Self -installed above -grade structures should only be used if excavation is not practical. . Concrete washout areas shall be constructed and maintained in sufficient quantity and size to contain all liquid and concrete waste generated by washout operations. Education . Discuss the concrete management techniques described in this BMP with the ready -mix con- cretesupplier before any deliveries are made. . Educate employees and subcontractors on the concrete waste management techniques described in this BMP. . Arrange for the contractor's superintendent or Certified Erosion and Sediment Control Lead (CESCL) to oversee and enforce concrete waste management procedures. . A sign should be installed adjacent to each concrete washout area to inform concrete equip- mentoperators to utilize the proper facilities. Contracts Incorporate requirements for concrete waste management into concrete supplier and subcontractor agreements. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 321 Location and Placement . Locate concrete washout areas at least 50 feet from sensitive areas such as storm drains, open ditches, water bodies, or wetlands. . Allow convenient access to the concrete washout area for concrete trucks, preferably near the area where the concrete is being poured. . If trucks need to leave a paved area to access the concrete washout area, prevent track -out with a pad of rock or quarry spalls (see BMP C105: Stabilized Construction Access). These areas should be far enough away from other construction traffic to reduce the likelihood of acci- dental damage and spills. . The number of concrete washout areas you install should depend on the expected demand for storage capacity. . On large sites with extensive concrete work, concrete washout areas should be placed in mul- tiple locations for ease of use by concrete truck drivers. Concrete Truck Washout Procedures . Washout of concrete truck drums shall be performed in designated concrete washout areas only. . Concrete washout from concrete pumper bins can be washed into concrete pumper trucks and discharged into designated concrete washout areas or properly disposed of off-site. Concrete Washout Area Installation . Concrete washout areas should be constructed as shown in the figures below, with a recom- mended minimum length and minimum width %J 10 ft, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. . Plastic lining material should be a minimum of 10 mil polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. . Lath and flagging should be commercial type. . Liner seams shall be installed in accordance with manufacturers' recommendations. . Soil base shall be prepared free of rocks or other debris that may cause tears or holes in the plastic lining material. Maintenance Standards Inspection and Maintenance . Inspect and verify that concrete washout areas are in place prior to the commencement of con- cretework. . Once concrete wastes are washed into the designated washout area and allowed to harden, 2019 Stormwafer Management Manual for Western Washington Volume 11 -Chapter 3 -Page 322 the concrete should be broken up, removed, and disposed of per applicable solid waste reg- ulations. Dispose of hardened concrete on a regular basis. During periods of concrete work, inspect the concrete washout areas daily to verify continued performance. o Check overall condition and performance. Check remaining capacity (%full). If using self -installed concrete washout areas, verify plastic liners are intact and side- walls are not damaged. If using prefabricated containers, check for leaks. . Maintain the concrete washout areas to provide adequate holding capacity with a minimum freeboard of 12 inches. . Concrete washout areas must be cleaned, or new concrete washout areas must be con- structed and ready for use once the concrete washout area is 75% full. . If the concrete washout area is nearing capacity, vacuum and dispose of the waste material in an approved manner. . Do not discharge liquid or slurry to waterways, storm drains or directly onto ground. . Do not discharge to the sanitary sewer without local approval. Place a secure, non -collapsing, non -water collecting cover over the concrete washout area prior to predicted wet weather to prevent accumulation and over of pre- cipitation. . Remove and dispose of hardened concrete and return the structure to a functional con- dition. Concrete maybe reused on-site or hauled away for disposal or recycling. . When you remove materials from aself-installed concrete washout area, build a new struc- ture; or, if the previous structure is still intact, inspect for signs of weakening or damage, and make any necessary repairs. Reline the structure with new plastic after each cleaning. Removal of Concrete Washout Areas . When concrete washout areas are no longer required for the work, the hardened concrete, slurries and liquids shall be removed and properly disposed of. . Materials used to construct concrete washout areas shall be removed from the site of the work and disposed of or recycled. . Holes, depressions or other ground disturbance caused by the removal of the concrete washout areas shall be backfilled, repaired, and stabilized to prevent erosion. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 323 Figure II -3.7: Concrete Washout Area with Wood Planks 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 324 3m Minimum Lath and flagging on 3 sides �J Sandbag Berm Sandbag 10 mil plastic lining Varies 0 A 0 f1 4_A r, 1 m U1 • / Berm O O 06 Section A -A 10 mil plastic lining Plan Notes: 1. Actual layout determined in the field. Type"Below Grade" 2. A concrete washout sign shall be installed within 10 m of the 3m Minimum IN temporary concrete washout facility. M Ba R9 RQ Wood frame B B securely fastened around entire perimeter with two stakes Varies 10 mil plastic lining Stake (typ.) m 5a Section 13=1310 mil plastic lining Two -stacked 2x12 rough Plan wood frame Type "Above Grade" with Wood Planks NOT TO SCALE moo Concrete Washout Area with Wood Planks Revised June 2016 DEPARTMENT OF ECOLOGY Please see http://www.ecy.wa.gov/copyilghthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 324 Figure II -3.8: Concrete Washout Area with Straw Bales Straw bale 10 mil plastic lining Binding wire Staples Native material (2 per bale) (optional) Wood or Plywood metal stakes 1200 mm x 610 mm Wood post (2 per bale) 4L4 painted white (89 mm x 89 mm Lag screws x 2.4 m) Section B -B (12.5 mm) IcoNCRETE Black letters WASHOUT l 150 mm height 915 mm 1 3m Minimum 91mm 9 Stake (typ) r I B� Varies Straw bale J (tm) DEPARTMENT OF ECOLOGY State of Washington Plan f u 5 Concrete Washout Si n Detail (or equivalent) �B 50 mm mm dia. 200 mm �� steel T steel wire Staale Detail 10 �— mil plastic lining Notes: 1. Actual layout determined in the field. 2. The concrete washout sign shall be installed within 10 m of the temporary concrete washout facility. e "Above Grade" with Straw Bales NOT TO SCALE Concrete Washout Area with Straw Bales Revised June 2016 Please see http://www.ecy.wa.gov/copyr/ghthtml for copyright notice including permissions, IimKation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 325 .mT' . Straw bale J (tm) DEPARTMENT OF ECOLOGY State of Washington Plan f u 5 Concrete Washout Si n Detail (or equivalent) �B 50 mm mm dia. 200 mm �� steel T steel wire Staale Detail 10 �— mil plastic lining Notes: 1. Actual layout determined in the field. 2. The concrete washout sign shall be installed within 10 m of the temporary concrete washout facility. e "Above Grade" with Straw Bales NOT TO SCALE Concrete Washout Area with Straw Bales Revised June 2016 Please see http://www.ecy.wa.gov/copyr/ghthtml for copyright notice including permissions, IimKation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 325 Figure II -3.9: Prefabricated Concrete Washout Container w/Ramp 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 326 I �I 4 � !I! � ` � � � �"�►_I:��r- '•tib NOT TO SCALE who •Prefabricated Concrete WashoutContainer �- • Revised June 2016 DEPARTMENT • ECOLOG YL Please see http.slAvww.ecywa,govlcopyrighthtmI for copyright notice including permissions, State of Washing ton liab limitation of ility, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 326 BMP C160: Certified Erosion and Sediment Control Lead Purpose The project proponent designates at least one person as the responsible representative in charge of erosion and sediment control (ESC), and water quality protection. The designated person shall be responsible for ensuring compliance with all local, state, and federal erosion and sediment control and water quality requirements. Construction sites one acre or larger that discharge to waters of the State must designate a Certified Erosion and Sediment Control Lead (CESCL) as the responsible representative. Conditions of Use A CESCL shall be made available on projects one acre or larger that discharge stormwater to sur- face waters of the state. Sites less than one acre may have a person without CESCL certification conduct inspections. The CESCL shall: . Have a current certificate proving attendance in an erosion and sediment control training course that meets the minimum ESC training and certification requirements established by Ecology. Ecology has provided the minimum requirements for CESCL course training, as well as a list of ESC training and certification providers at: https://ecology.wa.gov/Regulations-Permits/Permits-certifications/Certified-erosion-sed- iment-control OR . Be a Certified Professional in Erosion and Sediment Control (CPESC). For additional inform- ation go to: http://www.envirocertintl.org/cpesc/ Specifications . CESCL certification shall remain valid for three years. . The CESCL shall have authority to act on behalf of the contractor or project proponent and shall be available, or on-call, 24 hours per day throughout the period of construction. . The Construction SWPPP shall include the name, telephone number, fax number, and address of the designated CESCL. See ll -2 Construction Stormwater Pollution Prevention Plans (Construction SWPPPs). . A CESCL may provide inspection and compliance services for multiple construction projects in the same geographic region, but must be on site whenever earthwork activities are 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 327 occurring that could generate release of turbid water. Duties and responsibilities of the CESCL shall include, but are not limited to the following: Maintaining a permit file on site at all times which includes the Construction SWPPP and any associated permits and plans. Directing BMP installation, inspection, maintenance, modification, and removal. Updating all project drawings and the Construction SWPPP with changes made. Completing any sampling requirements including reporting results using electronic Dis- charge Monitoring Reports (WebDMR). Facilitate, participate in, and take corrective actions resulting from inspections per- formed by outside agencies or the owner. o Keeping daily logs, and inspection reports. Inspection reports should include: ■ Inspection date/time. ■ Weather information; general conditions during inspection and approximate amount of precipitation since the last inspection. ■ Visual monitoring results, including a description of discharged stormwater. The presence of suspended sediment, turbid water, discoloration, and oil sheen shall be noted, as applicable. ■ Any water quality monitoring performed during inspection. ■ General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. ■ A summary or list of all BMPs implemented, including observations of all erosion/sediment control structures or practices. The following shall be noted: 1. Locations of BMPs inspected. 2. Locations of BMPs that need maintenance. 3. Locations of BMPs that failed to operate as designed or intended. 4. Locations of where additional or different BMPs are required. BMP C162: Scheduling Sequencing a construction project reduces the amount and duration of soil exposed to erosion by wind, rain, runoff, and vehicle tracking. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 328 Conditions of Use The construction sequence schedule is an orderly listing of all major land -disturbing activities together with the necessary erosion and sedimentation control measures planned for the project. This type of schedule guides the contractor on work to be done before other work is started so that serious erosion and sedimentation problems can be avoided. Following a specified work schedule that coordinates the timing ofland-disturbing activities and the installation of control measures is perhaps the most cost-effective way of controlling erosion during construction. The removal of ground cover leaves a site vulnerable to erosion. Construction sequen- cing that limits land clearing, provides timely installation of erosion and sedimentation controls, and restores protective cover quickly can significantly reduce the erosion potential of a site. Design Considerations . Minimize construction during rainy periods. Schedule projects to disturb only small portions of the site at any one time. Complete grading as soon as possible. Immediately stabilize the disturbed portion before grading the next por- tion. Practice staged seeding in order to revegetate cut and fill slopes as the work progresses. II -3.3 Construction Runoff BMPs BMP C200: Interceptor Dike and Swale Purpose Provide a dike of compacted soil or a swale at the top or base of a disturbed slope or along the peri- meter of a disturbed construction area to convey stormwater. Use the dike and/or swale to intercept the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can prevent storm runoff from entering the work area or sediment -laden runoff from leaving the con- struction site. Conditions of Use Use an interceptor dike or swale where runoff from an exposed site or disturbed slope must be con- veyed to an erosion control BMP which can safely convey the stormwater. . Locate upslope of a construction site to prevent runoff from entering the disturbed area. . When placed horizontally across a disturbed slope, it reduces the amount and velocity ofrun- offflowing down the slope. . Locate downslope to collect runoff from a disturbed area and direct it to a sediment BMP (e.g. BMP C240: Sediment Trap or BMP C241: Sediment Pond (Temporary)). 2019 stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 329 Design and Installation Specifications Dike and/or swale and channel must be stabilized with temporary or permanent vegetation or other channel protection during construction. . Steep grades require channel protection and check dams. . Review construction for areas where overtopping may occur. . Can be used at the top of new fill before vegetation is established. . May be used as a permanent diversion channel to carry the runoff. . Contributing area for an individual dike or swale should be one acre or less. . Design the dike and/or swale to contain flows calculated by one of the following methods: Single Event Hydrograph Method: The peak volumetric flow rate calculated using a 10 - minute time step from a Type 1A, 10 -year, 24-hour frequency storm for the worst-case land cover condition. OR Continuous Simulation Method: The 10 -year peak flow rate, as determined by an approved continuous runoff model with a 15 -minute time step for the worst-case land cover condition. Worst-case land cover conditions (i.e., producing the most runoff) should be used for analysis in most cases, this would be the land cover conditions just prior to final landscaping). Interceptor Dikes Interceptor dikes shall meet the following criteria: . Top Width: 2 feet minimum. . Height: 1.5 feet minimum on berm. . Side Slope: 2H:1 V or flatter. . Grade: Depends on topography, however, dike system minimum is 0.5%, and maximum is 1%. . Compaction: Minimum of 90 percent ASTM D698 standard proctor. . Stabilization: Depends on velocity and reach. Inspect regularly to ensure stability. Ground Slopes <5%: Seed and mulch applied within 5 days of dike construction (see BMP C121: Mulching). . Ground Slopes 5 - 40%: Dependent on runoff velocities and dike materials. Stabilization should be done immediately using either sod or riprap, or other measures to avoid erosion. . The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall 2019 Stormwater Management Manual for Wesfern Washington Volume 11 -Chapter 3 -Page 330 occur at the outlet. Provide energy dissipation measures as necessary. Sediment -laden runoff must be released through a sediment trapping facility. Minimize construction traffic over temporary dikes. Use temporary cross culverts for channel crossing. . See Table II -3.8: Horizontal Spacing of Interceptor Dikes Along Ground Slope for recom- mended horizontal spacing between dikes. Table II -3.8: Horizontal Spacing of Interceptor Dikes Along Ground Slope Average Slope Slope Percent Flowpath Length 20H:1 V or less 3-5% 300 feet (10 to 20)H:1V 5-10% 200 feet (4 to 1Oft 1V 10-25% 100 feet (2 to 4)H:1V 25-50% 50 feet Interceptor Swales Interceptor swales shall meet the following criteria: . Bott om Width: 2 feet minimum; the cross-section bottom shall be level. . Depth: 14 00t minimum. . Side Slope: 2H:1V or flatter. . Grade: Maximum 5 percent, with positive drainage to a suitable outlet (such as BMP C241: Sediment Pond (Temporary)). . Stabilization: Seed as per BMP C120: Temporary and Permanent Seeding, or BMP C202: Riprap Channel Lining, 12 inches thick riprap pressed into the bank and extending at least 8 inches vertical from the bottom. Maintenance Standards . Inspect diversion dikes and interceptor swales once a week and after every rainfall. Imme- diatelyremove sediment from the flow area. . Damage caused by construction traffic or other activity must be repaired before the end of each working day. . Check outlets and make timely repairs as needed to avoid gully formation. When the area below the temporary diversion dike is permanently stabilized, remove the dike and fill and sta- bilize the channel to blend with the natural surface. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 331 thickness is 2 feet. For outlets at the base of steep slope pipes (pipe slope greater than 10 percent), use an engineered energy dissipator. Filter fabric or erosion control blankets should always be used under riprap to prevent scour and channel erosion. See BMP C122: Nets and Blankets. . Bank stabilization, bioengineering, and habitat features maybe required for disturbed areas. This work may require a Hydraulic Project Approval (H PA) from the Washington State Depart- ment of Fish and Wildlife. See 1-2.11 Hydraulic Project Approvals. Maintenance Standards . Inspect and repair as needed. . Add rock as needed to maintain the intended function. . Clean energy dissipator if sediment builds up. BMP C220: Inlet Protection Purpose Inlet protection prevents coarse sediment from entering drainage systems prior to permanent sta- bilization of the disturbed area. Conditions of Use Use inlet protection at inlets that are operational before permanent stabilization of the disturbed aI eas that contribute runoff to the inlet. Provide protection for all storm drain inlets downslope and within 500 feet of a disturbed or construction area, unless those inlets are preceded by a sediment trapping BMP. Also consider inlet protection for lawn and yard drains on new home construction. These small and numerous drains coupled with lack of gutters can add significant amounts of sediment into the roof drain system. If possible, delay installing lawn and yard drains until just before landscaping, or cap these drains to prevent sediment from entering the system until completion of landscaping. Provide 184ches of sod around each finished lawn and yard drain. Table I I-3.10: Storm Drain Inlet Protection lists several options for inlet protection. All of the methods for inlet protection tend to plug and require a high frequency of maintenance. Limit contributing drain- age areas for an individual inlet to one acre or less. If possible, provide emergency overflows with additional end -of -pipe treatment where stormwater ponding would cause a hazard. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 356 Table 11-3.10: Storm Drain Inlet Protection Design and Installation Specifications Excavated Drop Inlet Protection Excavated drop inlet protection consists of an excavated impoundment around the storm drain inlet. Sediment settles out of the stormwater prior to entering the storm drain. Design and installation spe- cifications for excavated drop inlet protection include: . Provide a depth of 1-2 ft as measured from the crest of the inlet structure. . Slope sides of excavation should be no steeper than 2H:1 V. . Minimum volume of excavation is 35 cubic yards. . Shape the excavation to fit the site, with the longest dimension oriented toward the longest inflow area. . Install provisions for draining to prevent standing water. . Clear the area of all debris. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 357 Applicable for Type of Inlet Pro- Emergency Paved/ Earthen Sur- Conditions of Use tection Overflow faces Drop Inlet Protection Yes, temporary Applicable for heavy flows. Easy Excavated drop flooding may Earthen to maintain. Large area requirement: inlet protection occur 30'x30'/acre Block and gravel Applicable for heavy concentrated flows. drop inlet pro- Yes � Paved or Earthen Will not pond. tection Gravel and wire Applicable for heavy concentrated flows. drop inlet pro- No Paved or Earthen Will pond. Can withstand traffic. tection Catch basin filters Yes Paved or Earthen Frequent maintenance required. Curb Inlet Protection Curb inlet pro- Small capacity Used for sturdy, more compact install- tection with overflow Paved ation. wooden weir Block and gravel curb inlet pro- Yes Paved Sturdy, but limited filtration. tection Culvert Inlet Protection Culvert inlet sed- N/A N/A 18 month expected life. iment trap Design and Installation Specifications Excavated Drop Inlet Protection Excavated drop inlet protection consists of an excavated impoundment around the storm drain inlet. Sediment settles out of the stormwater prior to entering the storm drain. Design and installation spe- cifications for excavated drop inlet protection include: . Provide a depth of 1-2 ft as measured from the crest of the inlet structure. . Slope sides of excavation should be no steeper than 2H:1 V. . Minimum volume of excavation is 35 cubic yards. . Shape the excavation to fit the site, with the longest dimension oriented toward the longest inflow area. . Install provisions for draining to prevent standing water. . Clear the area of all debris. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 357 . Grade the approach to the inlet uniformly. Drill weep holes into the side of the inlet. . Protect weep holes with screen wire and washed aggregate. . Seal weep holes when removing structure and stabilizing area. . Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass flow. Block and Gravel Filter A block and gravel filter is a barrier formed around the inlet with standard concrete blocks and gravel. See Figure lk3.17: Block and Gravel Filter. Design and installation specifications for block gravel fik ters include: . Provide a height of 1 to 2 feet above the inlet. . Recess the first row of blocks 2 -inches into the ground for stability. . Support subsequent courses by placing a pressure treated wood 2x4 through the block open- ing. . Do not use mortar. . Lay some blocks in the bottom row on their side to allow for dewatering the pool. . Place hardware cloth or comparable wire mesh with'/2-inch openings over all block openings. . Place gravel to just below the top of blocks on slopes of 2H:1 V or flatter. . An alternative design is a gravel berm surrounding the inlet, as follows: Provide a slope of 3H:1V on the upstream side of the berm. Provide a slope of 2H:1 V on the downstream side of the berm. Provide a 1400t wide level stone area between the gravel berm and the inlet. Use stones 3 inches in diameter or larger on the upstream slope of the berm. Use gravel 1/2- to %/ inch at a minimum thickness of 1 -foot on the downstream slope of the berm. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 358 Figure 11-3.17: Block and Gravel Filter 2019 Sformwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 359 A Drain grateo o goo �O �p o•oo o �OOQo block de�o�da�o ?�oa((j,oe o., Concrete �4 oC)ooCS�� o�� :� dOoo 0 6 0 moO �o� O0 0 0 Q*. 0 o 6 6 Gravel backfill °o Q O �oa�o o;Of�. 0 Q�oopo o p�Q OO� 4Oo. `OCQ p d OH •O94(D 80° 0 0 o oo o ° oO 0 00 ��l(�ll^�Ja��00� oQ o00 00 O o0 A Plan View Concrete block Wire screen or filter fabric Gravel backfill _Overflow water Ponding height o,o o _ o� 0Water `a. po Drop inlet Section XA Notes: 1. Drop inlet sediment barriers are to be used for small, nearly level drainage areas. (less than 5%) 2. Excavate a basin of sufficient size adjacent to the drop inlet. 3. The top of the structure (ponding height) must be well below the ground elevation downslope to prevent runoff from bypassing the inlet. A temporary dike may be necessary on the downslope side of the structure. NOT TO SCALE Block and Gravel Filter Revised June 2016 DEPARTMENT OF ECOLOGY Please see htfp://www.ecy.wa.gov/copyilghthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Sformwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 359 Gravel and Wire Mesh Filter Gravel and wire mesh filters are gravel barriers placed over the top %J the inlet. This method does not provide an overflow. Design and installation specifications for gravel and wire mesh filters include: . Use a hardware cloth or comparable wire mesh with'/z-inch openings. Place wire mesh over the drop inlet so that the wire extends a minimum of 1 -foot bey- ond each side of the inlet structure. Overlap the strips if more than one strip of mesh is necessary. . Place coarse aggregate over the wire mesh. Provide at least a 12 -inch depth of aggregate over the entire inlet opening and extend at least 184ches on all sides. Catch Basin Filters Catch basin filters are designed by manufacturers for construction sites. The limited sediment stor- age capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. To reduce maintenance requirements, combine a catch basin filter with another type of inlet protection. This type of inlet protection provides flow bypass without overflow and therefore may be a better method for inlets located along active rights-of-way. Design and install- ation specifications for catch basin filters include: . Provides 5 cubic feet of storage. . Requires dewatering provisions. Provides a high-flow bypass that will not clog under normal use at a construction site. . Insert the catch basin filter in the catch basin just below the grating. Curb Inlet Protection with Wooden Weir Curb inlet protection with wooden weir is an option that consists of a barrier formed around a curb inlet with a wooden frame and gravel. Design and installation specifications for curb inlet protection with wooden weirs include: . Use wire mesh with 1/2 -inch openings. . Use extra strength filter cloth. . Construct a frame. . Attach the wire and filter fabric to the frame. . Pile coarse washed aggregate against the wire and fabric. . Place weight on the frame anchors. 2019 Stormwafer Management Manual for Western Washington Volume 11 -Chapter 3 -Page 360 Block and Gravel Curb Inlet Protection Block and gravel curb inlet protection is a barrier formed around a curb inlet with concrete blocks and gravel. See Figure 1k3.18: Block and Gravel Curb Inlet Protection. Design and installation spe- cifications for block and gravel curb inlet protection include: . Use wire mesh with'/z-inch openings. . Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks. . Place a 2x4 stud through the outer holes of each spacer block to align the front blocks. . Place blocks on their sides across the front of the inlet and abutting the spacer blocks. . Place wire mesh over the outside vertical face. . Pile coarse aggregate against the wire to the top of the barrier. 2019 Stormwater Management Manual for Western Washington Volume 11 - Chapfer 3 -Page 361 Figure II -3.18: Block and Gravel Curb Inlet Protection 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 362 A Catch basin Back of sidewalk c::r Wood stud Back of curb Curb inlet ///2x4 Concrete block •s ° P Wire screen or R filter fabric ° o A %4 inch (20 mm) Concrete block Drain gravel Plan View Ponding height Y4 inch (20 mm) Drain gravel Overflow_ — — — 'r=+= Curb inlet \ Wire screen or filter fabric 2x4 Wood stud (100x50 Timber stud) Catch basin Concrete block Section A -A Notes: 1. Use block and gravel type sediment barrier when curb inlet Is located in gently sloping street segment, where water can pond and allow sediment to separate from runoff. 2. Barrier shall allow for overflow from severe storm event. 3. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. NOT TO SCALE moo Block and Gravel Curb Inlet Protection Revised June 2016 DEPARTMENT OF ECOLOGY Please see http://www.ecy.wa.gov/copyrlghthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 362 Curb and Gutter Sediment Barrier Curb and gutter sediment barrier is a sandbag or rock berm (riprap and aggregate) 3 feet high Cl" 3 feet wide in a horseshoe shape. See Figure lk3.19: Curb and Gutter Barrier. Design and installation specifications for curb and gutter sediment barrier include: . Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap, 3 feet high and 3 feet wide, at least 2 feet from the inlet. . Construct a horseshoe shaped sedimentation trap on the upstream side of the berm. Size the trap to sediment trap standards for protecting a culvert inlet. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 363 Figure II -3.19: Curb and Gutter Barrier 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 364 Back of sidewalk Burlap sacks to overlap onto curb Back of curb Runoff Curb Inlet Runoff Spillway Catch basin Plan View Gravel filled sandbags stacked tightly Notes: 1. Place curb type sediment barriers on gently sloping street segments, where water can pond and allow sediment to separate from runoff. 2. Sandbags of either burlap or woven 'geotextile' fabric, are filled with gravel, layered and packed tightly. 3. Leave a one sandbag gap in the top row to provide a spillway for overflow. 4. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. NOT TO SCALE moo Curb and Gutter Barrier Revised June 2016 DEPARTMENT OF ECOLOGY Please see http.Y/www.ecy.wa.govicopyright.html for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 364 Maintenance Standards . Inspect all forms of inlet protection frequently, especially after storm events. Clean and replace clogged catch basin filters. For rock and gravel filters, pull away the rocks from the inlet and clean or replace. An alternative approach would be to use the clogged rock as fill and put fresh rock around the inlet. . Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept these products, or may require additional testing prior to consideration for local use. Products that Ecology has approved as functionally equivalent are available for review on Ecology's website at: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C231: Brush Barrier Purpose The purpose of brush barriers is to reduce the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use . Brush barriers may be used downslope of disturbed areas that are less than one-quarter acre. . Brush barriers are not intended to treat concentrated flows, nor are they intended to treat sub- stantialamounts of overland flow. Any concentrated flows must be directed to a sediment trap- ping BMP. The only circumstance in which overland flow can be treated solely by a brush barrier, rather than by a sediment trapping BMP, is when the area draining to the barrier is small. . Brush barriers should only be installed on contours. Design and Installation Specifications . Height: 2 feet (minimum) to 5 feet (maximum). . Width: 5 feet at base (minimum) to 15 feet (maximum). . Filter fabric (geotextile) may be anchored over the brush berm to enhance the filtration ability of the barrier. Ten -ounce burlap is an adequate alternative to filter fabric. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 365 BMP C233: Silt Fence Silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use Silt fence maybe used downslope of all disturbed areas. . Silt fence shall prevent sediment carried by runoff from going beneath, through, or over the top of the silt fence, but shall allow the water to pass through the fence. . Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Convey any concentrated flows through the drainage system to a sediment trapping BMP. . Do not construct silt fences in streams or use in V-shaped ditches. Silt fences do not provide an adequate method of silt control for anything deeper than sheet or overland flow. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 370 Figure II -3.22: SIR Fence 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 371 Joints in geotextile fabric shall be spliced at posts. Use staples, wire rings or equivalent to attach fabric to posts 2"x2" by 14 Ga. wire or equivalent, if standard strength fabric used I '/Vx NX -- rr------ r� Minimum I I 6' max I I 4"x4" trench I I u � Post spacing may be increased 2"x2" wood posts, steel to 8' if wire backing is used fence posts, or equivalent 2"x2" by 14 Ga. wire or equivalent, if standard strength fabric used \�\\ Geotextile fabric 2' min Backfill trench with native soil or %" - /� /\/\ \ \ 1.5" washed gravel \/�2�mm� Minimum 4'x4" trench 2"x2" wood posts, steel fence posts, or equivalent NOT TO SCALE moo Silt Fence Revised July 2017 DEPARTMENT OF ECOLOGY Please see http://www.ecy.wa.gov/copyHghthtml for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 371 Design and Installation Specifications Use in combination with other construction stormwater BMPs. Maximum slope steepness (perpendicular to the silt fence line) 1 H:1 V. . Maximum sheet or overland flow path length to the silt fence of 100 feet. . Do not allow flows greater than 0.5 cfs. . Use geotextile fabric that meets the following standards. All geotextile properties listed below are minimum average roll values (i.e., the test result for any sampled roll in a lot shall meet or exceed the values shown in Table II -3.11: Geotextile Fabric Standards for Silt Fence): Table II -3.11: Geotextile Fabric Standards for Silt Fence Geotextile Property Minimum Average Roll Value 0.60 mm maximum for slit film woven (#30 sieve). Polymeric Mesh AOS 0.30 mm maximum for all other geotextile types (#50 sieve). (ASTM D4751) 0.15 mm minimum for all fabric types (#100 sieve). Water Permittivity 0.02 sec -1 minimum (ASTM D4491) Grab Tensile Strength 180 lbs. Minimum for extra strength fabric. (ASTM D4632) 100 lbs minimum for standard strength fabric. Grab Tensile Strength 30% maximum (ASTM D4632) Ultraviolet Resistance 70% minimum (ASTM D4355) . Support standard strength geotextiles with wire mesh, chicken wire, 2 -inch x 2 -inch wire, safety fence, orjute mesh to increase the strength of the geotextile. Silt fence materials are available that have synthetic mesh backing attached. . Silt fence material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of 0°F to 120°F. . One -hundred percent biodegradable silt fence is available that is strong, long lasting, and can be left in place after the project is completed, if permitted by the local jurisdiction. . Refer to Figure II -3.22: Silt Fence for standard silt fence details. Include the following Stand- ard Notes for silt fence on construction plans and specifications: 1. The Contractor shall install and maintain temporary silt fences at the locations shown in the Plans. 2. Construct silt fences in areas of clearing, grading, or drainage prior to starting those activities. 2019 stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 372 3. The silt fence shall have a 24eet min. and a 2'/2 -feet max. height above the original ground surface. 4. The geotextile fabric shall be sewn together at the point of manufacture to form fabric lengths as required. Locate all sewn seams at support posts. Alternatively, two sections of silt fence can be overlapped, provided that the overlap is long enough and that the adjacent silt fence sections are close enough together to prevent silt laden water from escaping through the fence at the overlap. 5. Attach the geotextile fabric onthe up-slope side of the posts and secure with staples, wire, or in accordance with the manufacturer's recommendations. Attach the geotextile fabric to the posts in a manner that reduces the potential for tearing. 6. Support the geotextile fabric with wire or plastic mesh, dependent on the properties of the geotextile selected for use. If wire or plastic mesh is used, fasten the mesh securely to the up-slope side of the posts with the geotextile fabric up-slope of the mesh. 7. Mesh support, if used, shall consist of steel wire with a maximum mesh spacing of 2 - inches, or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh shall be equivalent to or greater than 180 lbs. grab tensile strength. The polymeric mesh must be as resistant to the same level of ultraviolet radiation as the geotextile fabric it supports. 8. Bury the bottom of the geotextile fabric 4hes in below the ground surface. Backfill and tamp soil in place over the buried portion of the geotextile fabric, so that no flow can pass beneath the silt fence and scouring cannot occur. When wire or polymeric back-up support mesh is used, the wire or polymeric mesh shall extend into the ground 34ches min. 9. Drive or place the silt fence posts into the ground 18 -inches min. A 12—inch min. depth is allowed if topsoil or other soft aubgrade soil is not present and 18 -inches cannot be reached. Increase fence post min, depths by 6 inches if the fence is located on slopes of 3H:1 V or steeper and the slope is perpendicular to the fence. If required post depths cannot be obtained, the posts shall be adequately secured by bracing or guying to pre- vent overturning of the fence due to sediment loading. 10. Use wood, steel or equivalent posts. The spacing of the support posts shall be a max- imum of 6 -feet. Posts shall consist of either: . Wood with minimum dimensions of 2 inches by 2 inches by 3 feet. Wood shall be free of defects such as knots, splits, or gouges. . No. 6 steel rebar or larger. . ASTM A 120 steel pipe with a minimum diameter of 1 -inch. . U, T, L, or C shape steel posts with a minimum weight of 1.35 lbs./ft. . Other steel posts having equivalent strength and bending resistance to the post sizes listed above. 11. Locate silt fences on contour as much as possible, except ++k ends of the fence, 2019 Sformwater Management Manual for Western Washington Volume 11- Chapter3 -Page 373 where the fence shall be turned uphill such that the silt fence captures the runoff water and prevents water from flowing around the end of the fence. 12. If the fence must cross contours, with the exception of the ends of the fence, place check dams perpendicular to the back of the fence to minimize concentrated flow and erosion. The slope of the fence line where contours must be crossed shall not be steeperthan 3H:1V. . Check dams shall be approximately 1 -foot deep at the back of the fence. Check dams shall be continued perpendicular to the fence at the same elevation until the top of the check dam intercepts the ground surface behind the fence. . Check dams shall consist of crushed surfacing base course, gravel backfill for walls, or shoulder ballast. Check dams shall be located every 10 feet along the fence where the fence must cross contours. . Refer to Figure I I-3.23: Silt Fence Installation by Slicing Method for slicing method details. The following are specifications for silt fence installation using the slicing method: 1. The base of both end posts must be at least 2- to 4 -inches above the top of the geo- textile fabric on the middle posts for ditch checks to drain properly. Use a hand level or string level, if necessary, to mark base points before installation. 2. Install posts 3- to 44eet apart in critical retention areas and & to 74eet apart in standard applications. 3. Install posts 24 -inches deep on the downstream side of the silt fence, and as close as possible to the geotextile fabric, enabling posts to support the geotextile fabric from upstream water pressure. 4. Install posts with the nipples facing away from the geotextile fabric. 5. Attach the geotextile fabric to each post with three ties, all spaced within the top fl- inches ofthe fabric. Attach each tie diagonally 45 degrees through the fabric, with each puncture at least 1 4c vertically apart. Each tie should be positioned to hang on a post nipple when tightening to prevent sagging. 6. Wrap approximately 6 -inches of the geotextile fabric around the end posts and secure with 3 ties. 7. No more than 24 -inches of a 36 -inch geotextile fabric is allowed above ground level. 8. Compact the soil immediately next to the geotextile fabric with the front wheel of the tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the upstream side first and then each side twice for a total of four trips. Check and correct the silt fence installation for any deviation before compaction. Use a flat -bladed shovel to tuck the fabric deeper into the ground if necessary. 2019 Stormwater Management Manual for Western Washington Volume 11- Chapfer 3 -Page 374 Figure II -3.23: silt Fence Installation by Slicing Method 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 375 Ponding height max. 24" POST SPACING: 7' max. on open runs Attach fabric to 4' max. on pooling areas Top of Fabric upstream side of post Belt FLOW —► POST DEPTH: top 8" Drive over each side of As much below ground If 444 silt fence 2 to 4 times as fabric above ground 114 with device exerting 60 p.s.i, or greater Diagonal attachment 100% compaction 100% compaction doubles strength ITI=l11—III LI=III1�1's`ITILu I -LI I_1-ll==tU 1=III=W=111= =IIITLI=T=T III=1 I I -1H1=1=1 I =I 1=1—=LIl=ill— —LII=�—LII-1—Tll: III=1�-1111 E—I I la I I—I I I— a I -111—I 11-111-111—III: t:RI TI Il -I II—III=—LII= Attachment Details: —lll-1J-111 01=1II =111=W-111-11 I Gather fabric at posts, if needed. 1 I 1=1 11=�— CL: I I I=1TI=1 f=1 I- 11= —1=1I=1) I=111=111=1=1=1I' N Utilize three ties per post, all within top 8" �=III=II-1=IE1=II=1T1=1 T I- of fabric. -III—III—J1—LI IEE=ll =1= Position each tie diagonally, puncturing f=1 11=1 -fl I I—III—III I� I I—III—III—I l-J-uj-T=1 1 holes vertically a minimum of 1" apart. Hang tighten ;III -III,, -III -III 111-III-III-� each tie on a post nipple and No more than 24" of a 36" securely. Use cable ties (50 lbs) or soft fabric is allowed above ground wire. Roll of silt fence � Operation Post installed Fabric after above compaction Oground Silt Fence 200 I II FII I �I I IMI11LI 11-111-111-111 1111I1 300mm 1iTll 1111 IT 11-11 IMI—I I I—I I1=1I 1r Horizontal chisel point J Slicing blade (76 mm width) (18 mm width) Completed Installation Vibratory plow Is not acceptable because of horizontal compaction NOT TO SCALE Silt Fence Installation by Slicing Method Revised June 2016 DEPARTMENT OF ECOLOGY Please see hffp:lAvww.ecy.wa.govlcopyHghthtml for copyright notice including permissions, State of Washingtonj limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 375 Maintenance Standards Repair any damage immediately. . Intercept and convey all evident concentrated flows uphill of the silt fence to a sediment trap- ping BMP. . Check the uphill side of the silt fence for signs of the fence clogging and acting as a barrier to flow and then causing channelization of flows parallel to the fence. If this occurs, replace the fence and remove the trapped sediment. . Remove sediment deposits when the deposit reaches approximately one-third the height of the silt fence, or install a second silt fence. Replace geotextile fabric that has deteriorated due to ultraviolet breakdown. BMP C234: Vegetated Strip Purpose Vegetated strips reduce the transport of coarse sediment from a construction site by providing a physical barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use . Vegetated strips maybe used downslope of all disturbed areas. . Vegetated strips are not intended to treat concentrated flows, nor are they intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to BMP C241: Sediment Pond (Temporary) or other sediment trapping BMP. The only circumstance in which overland flow can be treated solely by a vegetated strip, rather than by a sediment trapping BMP, is when the following criteria are met (see Table 11- 3.12: Contributing Drainage Area for Vegetated Strips): Table II -3.12: Contributing Drainage Area for Vegetated Strips Average Contributing Area Slope Average Contributing Area Per- cent Slope Max Contributing area Flowpath Length 1.5H:1Vorflatter 67%orflatter 100 feet 2H : 1V orflatter 50% orflatter 115 feet 4H : 1V orflatter 25% orflatter 150 feet 6H : IV or flatter 16.7% orflatter 200 feet 1 OH : 1 V or flatter 10% or flatter 250 feet 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 376 Design and Installation Specifications . The vegetated strip shall consist of a continuous strip of dense vegetation with topsoil fora min- imum of a 25400t length along the flowpath. Grass -covered, landscaped areas are generally not adequate because the volume of sediment overwhelms the grass. Ideally, vegetated strips shall consist of undisturbed native growth with a well-developed soil that allows for infiltration of runoff. . The slope within the vegetated strip shall not exceed 4H:1 V. . The uphill boundary of the vegetated strip shall be delineated with clearing limits. Maintenance Standards . Any areas damaged by erosion or construction activity shall be seeded immediately and pro- tected by mulch. . If more than 5 feet of the original vegetated strip width has had vegetation removed or is being eroded, sod must be installed. . If there are indications that concentrated flows are traveling across the vegetated strip, water runoff runoff controls must be installed to reduce the flows entering the vegetated strip, or addi- tional perimeter protection must be installed. BMP C235: Wattles Purpose Wattles are temporary erosion and sediment control barriers consisting of straw, compost, or other material that is wrapped in netting made of natural plant fiber or similar encasing material. They reduce the velocity and can spread the flow of rill and sheet runoff, and can capture and retain sed- iment. Conditions of Use . Watt les shall consist of cylinders of plant material such as weed -free straw, coir, wood chips, excelsiorI or wood fiber or shavings encased within netting made of natural plant fibers unaltered by synthetic materials. . Use wattles: o In disturbed areas that require immediate erosion protection. On exposed soils during the period of short construction delays, or over winter months. On slopes requiring stazation until permanent vegetation can be established. material used dictates the effectiveness period of the wattle. Generally, wattles are effect- ive for one to two seasons. 2019 Stormwater Management Manual for Western Washington Volume 11 - Chapfer3 -Page 377 Prevent rilling beneath wattles by entrenching and overlapping wattles to prevent water from passing between them. Design Criteria Figure II -3.24: Wattles for typical construction details. . Wattles are typically 8 to 10 inches in diameter and 25 to 30 feet in length. . Install wattles perpendicular to the flow direction and parallel to the slope contour. Place wattles in shallow trenches, staked along the contour of disturbed or newly constructed slopes. Dig narrow trenches across the slope (on contour) to a depth of 3- to 5 -inches on clay soils and soils with gradual slopes. On loose soils, steep slopes, and areas with high rainfall, the trenches should be dug to a depth of 5- to 7- inches, or 1/2 to 2/3 of the thickness of the wattle. . Start building trenches and installing wattles from the base of the slope and work up. Spread excavated material evenly along the uphill slope and compact it using hand tamping or other methods. . Construct trenches at intervals of 10- to 25 -feet depending on the steepness of the slope, soil type, and rainfall. The steeper the slope the closer together the trenches. . Install the wattles snugly into the trenches and overlap the ends of adjacent wattles 12 inches behind one another. . Install stakes at each end of the wattle, and at 4 -foot centers along entire length of wattle. . If required, install pilot holes for the stakes using a straight bar to drive holes through the wattle and into the soil. . Wooden stakes should be approximately 0.75 x 0.75 x 24 inches in Willow cuttings or 3/8 - inch rebar can also be used for stakes. . Stakes should be driven through the middle of the wattle, leaving 2 to 3 inches of the stake pro- truding above the wattle. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 378 Figure 1143.24: Wattles 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 379 3' - 4' 'i (1.2m) \1I' /Y1`� ��1 ,, OM1 Overlap adjacent le I rolls 12" behind one another Straw rolls must be placed along slope contours �I,l 101 - 25' (3-8m) Spacing depends on soil type and slope steepness Sediment, organic matter, and native seeds are captured behind the rolls. 3" - 5" (75-125mm) x Ile, 8" - 10" Dia. (200-250mm) Live Stake 1" x 1" Stake l/ (25 x 25mm) NOTE: 1. Straw roll installation requires the placement and secure staking of the roll in a trench, 3" - 5" (75-125mm) deep, dug on contour. Runoff must not be allowed to run under or around roll. NOT TO SCALE Wattles Revised December 2016 DEPARTMENT OF ECOLOGY Please see http://www.ecy.wa.gov/copyr/ght.html for copyright notice including permissions, State of Washington limitation of liability, and disclaimer. 2019 Stormwater Management Manual for Western Washington Volume II -Chapter 3 -Page 379 Maintenance Standards • Wattles may require maintenance to ensure they are in contact with soil and thoroughly entrenched, especially after significant rainfall on steep sandy soils. Inspect the slope after significant storms and repair any areas where wattles are not tightly abutted or water has scoured beneath the wattles. Approved as Functionally Equivalent Ecology has approved products as able to meet the requirements of this BMP. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept these products, or may require additional testing prior to consideration for local use. Products that Ecology has approved as functionally equivalent are available for review on Ecology's website at: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-per- mittee-guidance-resources/Emerging-stormwater-treatment-technologies BMP C236: Vegetative Filtration Purpose Vegetative filtration as a BMP is used in conjunction with detention storage in the form of portable tanks or BMP C241: Sediment Pond (Temporary), BMP C206: Level Spreader, and a pumping sys- tem with surface intake. Vegetative filtration improves turbidity levels of stormwater discharges byfil- tering runoff through existing vegetation where undisturbed forest floor duff layer or established lawn with thatch layer are present. Vegetative filtration can also be used to infiltrate dewatering waste from foundations, vaults, and trenches as long as runoff does not occur. Conditions of Use For every five acres of disturbed soil use one acre of grass field, farm pasture, or wooded area. Reduce or increase this area depending on project size, ground water table height, and other site conditions. . Wetlands shall not be used for vegetative filtration. . Do not use this BMP in areas with a high ground water table, or in areas that will have a high seasonal ground water table during the use of this BMP. . This BMP may be less effective on soils that prevent the infiltration of the water, such as hard till. Using other effective source control measures throughout a construction site will prevent the generation of additional highly turbid water and may reduce the time period or area need for this BMP. . Stop distributing water into the vegetated filtration area if standing water or erosion results. 2019 Stormwater Management Manual for Western Washington Volume 11 -Chapter 3 -Page 380 C. 1 SC Plans Page X33 v,. —��M FM FM FM— I I VV II I r-- INSTALL STABILIZED CONSTRUCTION ENTRANCE BMP CiOSr SEE SHEET 4 INLET SEDIMENT PROTECTION SMP C420 TOPOGRAPHIC NOTE: THE EXISTING TOPOGRAPHIC DATA SHOWN ON THESE DRAWINGS HAS BEEN PREPARED, IN PART, BASED UPON INFORMATION FURNISHED BY OTHERS, WHILE THIS INFORMATION IS BELIEVED TO BE RELIABLE, HGP CANNOT ENSURE ITS ACCURACY AND THUS IS NOT RESPONSIBLE FOR THE ACCURACY OF THAT INFORMATION OR FOR ANY ERRORS OR SHALL OMISSIONS WHICH MAY HAVE BEEN INCORPORATED INTO THESE CALLING DRAWINGS AS A RESULT. EXISTING ASPHALT DRAINAGE SWALE TO BE REPLACED WITH STRUCTURE CLEARING LIMITS FLOW PATH TO EXISTING STORMWATER SWALE TO BE REESTABLISHED ONSITE AS PERMEABLE PAVEMENT OVERFLOW NOTE: THE CONTRACTOR SHALL BE FULLY RESPONSIBLE FOR THE LOCATION THIS DRAVv1NG DOES NOT REPRESENT A RECORD DOCUMENT, UNLESS AND PROTECTION OF ALL EXISTING UTILITIES, THE CONTRACTOR CERTIFIED BY HATTON GODAT PANTIER. VERIFY ALL UTILITY LOCATIONS PRIOR TO CONSTRUCTION BY THE UNDERGROUND LOCATE UNE AT 811 A MINIMUM OF 48 ANY ALTERATIONS TO THE DESIGN SHOWN HEREON MUST BE HOURS PRIOR TO ANY EXCAVATION. REVIEWED AND APPROVED BY HATTON GODAT PANTIER. EXISTING ASPHALT DRAINAGE SWALE STRIP TO SE REMOVED \ \ EXISTING GRAVEL ROAD .- TO BE REMOVED CITY OF YELM i w U 111 VERTICAL DATUM MERIDIAN HORIZONTAL DATUM THURSTON COUN TY BM #596 CONC. MON. WITH BRASS DISK -GPS 2 SHORT SUBDIVISION GP52A7INT. 103RD AVE. B CREEK RD. NO. SS -8028, VOL25, ELEV.= 338,31 PG 304 (NGVO 1929) LEGEND uuun• CLEARING UMITS - FILTER FABRIC FENCING MONITORING WELL LOCATIONS LET SEDIMENT PROTECTION I \ i � I � G Ria aRo� yh M FFR A DRAINAGE SWALE W 793.53 ROCK CNECN DAM (BMP C407) TOP EL 5343 TO MATCH WEST END OF SWALE SEE DETAIL SHEET 4 20 10 0 20 40 SCALE: 1" = 20' FILTER FABRIC FENCING AT LIMITS OF CLEARING 8 GRADING BMP 0433 FILTER FABRIC FENCING AND CLEARING LIMITS FENCING MAY m BE COMBINED BY USING ORANGE FILTER FABRIC FENCING W WHEN APPROVED BY JURISDICTION AND INSPECTOR EXISTING STORM POND W o N J m m � z Q�Q U K 2 Q U O O U O N APPROVED FOR CONSTRUCTION BY: DATE: gGD1CY NO. 2020,0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM 3 OF 17 SHEET: EgN19-0W/19-0 c d/ g APPROVAL EXPIRES: INDEX: 19-035 endw JOB: 19-035 3 FILTER FABRIC FENCING AT LIMITS OF CLEARING 8 GRADING BMP 0433 FILTER FABRIC FENCING AND CLEARING LIMITS FENCING MAY m BE COMBINED BY USING ORANGE FILTER FABRIC FENCING W WHEN APPROVED BY JURISDICTION AND INSPECTOR EXISTING STORM POND W o N J m m � z Q�Q U K 2 Q U O O U O N APPROVED FOR CONSTRUCTION BY: DATE: gGD1CY NO. 2020,0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM 3 OF 17 SHEET: EgN19-0W/19-0 c d/ g APPROVAL EXPIRES: INDEX: 19-035 endw JOB: 19-035 3 ROCK CHECK DAM 2018 STORMWATER MANAGEMENT MANUAL FOR W ESTERN WASHINGTON VOLUME 11, CHAPTER 3, FIGURE 1 W.18 BMP C207 STRAW WATTLES DETAIL 3018 STORMWATER MANAGEMENT MANUAL FOR WESTERN WASHINGTON VOLUME It, CHAPTER 3, View Looking Upstream lV t� CJI MINI I � W A, Section A -A 1 IF-sae,I Spacing Between Check Dams 3' V�Izwmat ,... % �.i'M<. G os�2zmml Ii N) • Rock Check Dam wm,.w..w mw.e...we,o OF ECOMEN7 LOGY Wattles It af n,.m•. d2.aw.w s•.wu®w 200 ROCK CHECK DAM 2018 STORMWATER MANAGEMENT MANUAL FOR W ESTERN WASHINGTON VOLUME 11, CHAPTER 3, FIGURE 1 W.18 BMP C207 STRAW WATTLES DETAIL 3018 STORMWATER MANAGEMENT MANUAL FOR WESTERN WASHINGTON VOLUME It, CHAPTER 3, lV N'. W Y a uP�l �•.+••P... ..e.•a •v+• •.,., 3' V�Izwmat G os�2zmml Ii N) • wm,.w..w mw.e...we,o Wattles s•.wu®w 200 ARTMENT OF ECOLOGY „w„...,�,,,,,,2•,aa,,,,,,,,b�„a„m wm„2�,,,„e,. m.w.� marw+2.wm.x�. FIGURE IIJ.34 BMP 0235 1. CONSTRUCTION ON THIS SITE SWILL BE CONDUCTED SUBSTANTIALLY IN ACCORDANCE WITH THE APPROVED PLANS. DEVIATIONS FROM THESE PIANS SHALL BE SUBMITTED TO THE PROJECT ENGINEER AND REM EW ING AGENCY, DEVIATIONS MUST BE APPRWED PRIOR TO ANY SITE DISTUFIR NO ACTIVITY NOT CONTAINED WITHIN THE APPROVED PLANS, 2. FOR DEVELOPMENT OF THI5 SITE. THE FOLLOWING GENERAL SEQUENCE SHALL BE OBSERVED, A, INSTALL STABILIZED CONSTRUCTION ENTRANCE TO PROVIDE SITE ACCESS AT INDICATED CONSTRUCTION ENTRANCE LOCATION. INSTALL VEGETATION PROTECTION FENCING AND TREE PROTECTION FENCING AS SHOWN IN THESE PLANS, B. CALL FOR INSPECTION BY THE REVIEWING AGENCY AND PROJECT ENGINEER C. BEGIN TREE CLEARING AND GRUBBING OF AREAS WHICH ARE TO BE GRADED, O. BEGIN GRADING OF AREA TO SUBGRADE AS SPECIFIED, E. INSTALLATION OF STORM DRAINAGE FACIUTIES (I.E., PIFlNG, CATCH BASINS, AND OTHER UTILITIES.) F. STRUCTURE CONSTRUCTION, G. PERMEABLE PAVEMENT SURFACE ANDCOMPACT TO W%-92% COMPACTION, INSTALL POROUS PAVEMENT SECTION PER SHEETS. H PERMANENT EROSION CONTROL MEASURES (IJ:., HYDROSEEDING. GRASSING, PLANTINGS, ETC,) ].ONCE THE SITE HAS BEEN 0SPURRED, CONTINUE OPERATIONS DILIGENTLY TOWARD COMPLETION AND STABILIZATION OF THE SITE, 4, MOMTOR ALL EROSION CONTROL FACILITIES, REPAIR, MOD FY, AND ENHANCE AS 0RECTED OR AS REQUIRED, GGNGRETE HANDLING NOTEe: BMP 0151 1. ANY TIME CONCRETE IS USED THESE MANAGEMENT PRACTICES SHALL BE UTILIZED. 2. CONCRETE PROJECTS INCLUDE BUT ARE NOT LIMITED TO CURBS, SIDEWALKS, ROADS, DRIVEWAYS, BRIDGES, FOUNDATIONS, FLOORS, STREET LIGHT BASES AND UTILITY BLOCKING, 3. CONCRETE EQUIPMENT SHALL BE WASHED OUT ONLY IN FORMED VASH OUT" AREAS, 4. UN USED CONCRETE SHALL BE RETURNED TO THE BATCH PL ANT FOR RECYCLING. 5. CONCRETE WASHOUTAREAS SHALL BE CHECKEDAND REPAIRED DAILY. 1. SAW CUTTING AND SURFACING OPERATIONS GENERATE SLURRY AND PROCESS WATER THAT CONTAIN FITUE PARTICULATES AND HIGH PH. 2. ANYTIME SAW CUTTING AND SURFACING OPERATIONS TAKE PLACE, THESE BEST MANAGE PRACTICES SHALL BE UTILIZED, 3. SAW CUTTING AND SURFACING OPERATIONS INCLUDING BUT NOT LIMITED TO CONCRETE SAWING, CORING, GRINDING, ROUGHENING OR HYDRODEMOUTION. 4. SLURRY AND CUTTINGS SHALL BE VACUUMED DURING OPERATIONS. 5, SLURRY AND CUTTINGS SHALL NOT REMAIN EXPOSEDTO THE ELEMENTS OVERNIGHT. 6, SLURRY AND CUTTINGS SHALL NOT BE ALLOWED TO DRAIN TO NATURAL OR CONSTRUCTED DRAINAGE CONVEYANCE PATHS 7, COLLETED SLURRY AND CUTTINGS SHALL BE DISPOSED OF INA MANNER THAT DOES NOT VIOLATE GROUNDWATER OR SURFACE WATER QUALITY STANDARDS. B. WASTE MATERIAL AND DEMOUTION DEBRIS MUST BE HANDLED IN A MANNER THAT DOES NOT CAUSE CONTAMINATION OF WATER, IF THE AREA IS SWEPT WITH A MECHANICAL SWEEPER, THE MATERIAL MUST BE HAULED OUT OF THE AREA TO AN APPROVED DISPOSAL SITE. 1. ALL DEWATERING FROM OPEN CUT EXCAVATION, TUNNELING, FOUNDATION WORK TRENCHING OR UNDERGROUND VAULTS SHALL BE DISCHARGED INTO A CONTROLLED CONVEYANCE SYSTEM PRIOR TO DISCHARGE TO A SEDIMENT TRAP OR POND, 2 CHANNELS USED FOR THIS PURPOSE WILL BE STABILIZED WITH EROSION BLANKETS, CHECK DAMS, SEEDING, SODDING, MULCHING, OUTLET PROTECTION AND/OR ANY OTHER MEANS DEEMED NECESSARY BY THE PROJECT CESCL TO ENSURE EROSION AND BE CONTROL STANDARDS ARE MET. 3. HIGHLY TURBID DEWATERING WATER FROM SOILS KNOWN OR SUSPECTED TO BE CONTAMINATED, OR FROM USE OF CONSTRUCTION EQUIPMENT, WILL REQUIRE ADDITIONAL MONITORING AND TREATMENT FOR THE SPECIFIC POLLUTANT(S) BASED ON THE CONTAMINATION. 4. WHEN DEWATERING WATER IS BEING DISCHARGED TO A WATER BODY WITH APOLLUTANT(S) OF CONCERN. THE DEWATERING WATER MUST BE MONITORED IN ACCORDANCE WITH CHAPTER 6 OF THE CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (SWPPP) FOR THE PROJECT. 5. SUCH MONITORING IS THE RESPONSIBILITY OF THE CONTRACTOR, e. THE DEWATERING OF SOILS KNOWN TO BE FREE OF CONTAMINATION WILL AT A MINIMUM, TRIGGER BMP'S TO TRAP BE AND REDUCE TURBIDITY. 7. ATAMNIMUM, GEOTEXTILE FABRIC SOCKSIBAGS/CELLS WILL BE USED TO FILTER THIS MATERIAL PRIOR TO ITS RELEASE TO A RELATIVELY LEVEL VEGETATED AREA e. WHERE NOT COST PROHIBITIVE, DEWATERING WATER, AFTER BEING FILTERED BY A GEOTEXTILE FABRIC SOCK/BAG/OR CELL SHOULD BE DIRECTED TO ONE OF THE PONDS FOR INFILTRATION OR METERED RELEASE. 9. OTHER BMP'S TO BE USED O SED FOR INTENT TRAPPING AND TURBIDITY REDUCTION INCLUDE' •CONCRETE HANDUNG BMP C 151 . TEMPORARY SEDIMENT POND BMP C241 (POND'B) •INFILTRATION (POND'A) •USE OF A SEDIMENT BAG WITH OUTFALL TO A VEGETATED SWALE FOR SMALL VOLUMES OF LOCALIZED DEWATERING .CONSTRUCTION STORMWATER FILTRATION BMP C251 THE PROJECT CESCL SHOULD DETERMINE WHICH BMP'S ARE MOST APPROPRIATE FOR SPECIFIC DEWATERING USES, CONSTRUCTION STORMWATER FILTRATION SHOULD ONLY BE USED AS A UST RESORT WHEN ALL OTHER OPTIONS HAVE BEEN EXHAUSTED AND THE SITE CANNOT MEET TURBIDITVIPOLLUTION MONITORING REQUIREMENTS OTHERWISE, EROSION CONTROL SEEDING NOTEB: BMP 0120 1. SEED M ASS, 50% SHALL N 4 L RYE, 5% INGS OR ANNUAL BLUEGRASS, 50%PERENNIAL RYE, 5%RED TOP OR COLONIAL BENTGRASS AND 5% WHITE DUTCH CLOVER APPLIED AT THE RATE OF 120 POUNDS PER ACRE. 2. SEED BEDS PLANTED BETWEEN MAY I AND OCTOBER 31 WILL REQUIRE IRRIGATION AND OTHER MAINTENANCE AS NECESSARY TO FOSTER AND PROTECT THE ROOT STRUCTURE. 3. FOR SEED BEDS PLANTED BETWEEN OCTOBER 31 AND APRIL 30, ARMORING OF THE SEED BED WILL BE NECESSARY GEOTEXTILES,JUTE MAT, CLEAR PLASTIC COVERING). 4. BEFORE SEEDING, INSTALL NEEDED SURFACE RUNOFF CONTROL MEASURES SUCH AS GRADIENT TERRACES, INTERCEPTOR DIKES, SWALES, LEVEL SPREADERS AND SEDIMENT BASINS. 5. THE SEEDBED SHALL BE FIRM WITH A FAIRLY FINE SURFACE, FOLLOWING SURFACE ROUGHENING. PERFORM ALL CULTURAL OPERATIONS ACROSS OR AT RIGHT ANGLES TO THE SLOPE. 6. FERTIUZERS ARE TO BE USED ACCORDING TO SUPPLIERS RECOMMENDATIONS. AMOUNTS USED SHOULD BE MINIMIZED, ESPECIALLY ADJACENT TO WATER BODIES AND WETLANDS. 1. MULCH MATERIALS USED SHALL BE HAV OR STRAW, AND SHP1L BE APPLIED AT THE RATE OF 2 - 3 TONS / ACRE OR OTHER WOOD FIBER CELLULOX MATERIAL TO BE APPLIED AT THE RATE OF APPROXIMATELY 100 TONS/ACRE 2 MULCHES SHALL BE APPLIED IN ALL AREAS WITH EXPOSED SOILS. 3, MULCHING SHALL BE USED IMMEDIATELY AFTER SEEDING OR IN AREAS WHICH CANNOT BE SEEDED BECAUSE OF THE ON. 4. PLL AREAS NEEDING MULCH SHALL BE COVERED BY NOVEMBER I. 5. MULCH MUST BE MAINTAINED UNTIL SITE FLAB ESTABLISHED 80%GRASS COVERAGE. FILL EASTABILIZATION: 1, ALL FILL AREA SLOPES SHALL BE ROUGHENED USING ONE OF THE METHODS FROM BMP C130 AS FILL IS BEING PLACED. 2. ALI DISTURBEDAREAS SHALL BE SEEDED AND MULCHED PER THE NOTES AND DETAILS IN THIS PLAN SET AND PER BMPS C120 ANDC121. 3. IN NO CASE SHALL DISTURBED SOILS REMAIN UNSTABILIZED AND UNWORKED FOR MORE TRAN 7 DAYS DURING THE DRY SEg5ON (MAY I TO SEPTEMBER 30) OR MORE TRAN 2 DAYS DURING THE WET SEASON (OCTOBER 1 TO APRIL 30) AS MANUFACTURED BY STREAMGUARID (#3001) BY RETRIEVAL STRAP FOSS ENVIRONMENTAL OR EQUIVALENT B 36• ADAPTER SKIRT J OVERFLEW NDERIFLOW GEOTEXTILE FABRIC DISCHARGE PEAK STROM I - I `Ir VOLUMES ) OIL SORBENT FILTER I -SEDIMENT ACCUMULATION INLET SEDIMENT PROTECTION (BMP C220) N.T.S. INLET SEDIMENT PROTECTION NOTES: (BMP C220) 1. INSTALL INSERT PER THE MANUFACTURER'S SPECIFICATIONS 2. MAINTAIN AND REPLACE INSERTS AS RECOMMENDED BY THE MANUFACTURER, AS REQUIRED BY THE INSPECTOR OR PROJECT ENGINEER, AND AS OTHERWISE NECESSARY. JOINTS IN FILTER FABRIC SHALL BE SPILICED AT POSTS, USE STAPLES OR WIRE RING TO ATTACH FABRIC TO POSTS. 7k2'k14GA WIRE FABRIC OR EQUIVALENT IF STANDARD STRENGTH FABRIC USED BURY BOTTOM OF FILTER MATERIAL IN 4'k4' TRENCH �. STANDARD OR BETTER OR EQUAL ALTERNATIVE: STEEL FILTER FABRIC FENCE POSTS 2"X2'k14GA_ WIRE FABRIC OR EQUIVALENT IF STANDARD STRENGTH FABRIC USED n .r PROVIDE 3/4'-112" WASHED GRAVELBACKFILL IN �/ TRENCH 4"MIN, Z'X4' WOOD POSTS, STANDARD OR BETTER OR EQUAL ALTERNATIVE: STEEL FENCE POSTS FILTER FABRIC FENCE DETAIL (BMP C233) N.T.S. 1. FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT TO THE LENGTH OF THE BARRIER 70 AVOID USE OF JOINTS, WHEN JOINTS ARE NECESSARY, FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY AT A SUPPORT POST, WITH A MINIMUM 8 -INCH OVERLAP, AND SECURELY FASTENED AT BOTH ENDS TO POST, 2. POSTS SHALL BE SPACED A MAXIMUM OF 6 FEET APART AND DRIVEN SECURELY INTO THE GROUND (MINIMUM OF 12 INCHES), 3. ATRENCH SHALL BE EXCAVATED APPROXIMATELY 4 INCHES WIDE AND 4 INCHES DEEP ALONG THE UNE OF POSTS AND UPSLOPE FROM THE BARRIER. 4. WHEN STANDARD STRENGTH FILTER FABRIC IS USED, A WIRE MESH SUPPORT FENCE SHALL BE FASTENED SECURELY TO THE UPSLOPE SIDE OF THE POSTS USING HEAVY-DUTY WIRE STAPLES AT LEAST 1 INCH LONG, TIE WIRES OR HOG RINGS. THE WIRE SHALL EXTEND INTO THE TRENCH A MINIMUM OF 41NCHES AND SHALL NOT EXTEND MORE THAN 241NCHESABOVETHE ORIGINAL GROUND SURFACE. 5. THE STANDARD STRENGTH FILTER FABRIC SHALL BE STAPLED OR WIRED TO THE FENCE, AND 20 INCHES OF THE FABRIC SHALL BE EXTEND ED INTO THE TRENCH. THE FABRIC SHALL NOT EXTEND MORE THAN 24 INCHES ABOVE THE ORIGINAL GROUND SURFACE. FILTER FABRIC SHALL NOT BE STAPLED TO EXISTING TREES. e. WHEN EXTRA -STRENGTH FILTER FABRIC AND CLOSER POST SPACING IS USED, THE WIRE MESH SUPPORT FENCE MAYBE ELIMINATED. IN SUCH A CASE, THE FILTER FABRIC IS STAPLED OR WIRED DIRECTLY TO THE POSTS WITH ALL OTHER PROVISIONS OF ABOVE NOTES APPLYING, 7. FILTER FABRIC FENCES SHALL NOT BE REMOVED BEFORE THE UPSLOPE AREA HAS BEEN PERMANENTLY STABILIZED, 6, FILTER FABRIC FENCES SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALLAND AT LEAST DAILY DURING PROLONGED RAINFALL. ANY REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY. 1. APPROVAL OF THIS EROSIOWSEDIMENTATION CONTROL (ESC) PLAN DOES NOT CONSTITUTE AN APPROVAL OF PERMANENT ROAD OR DRAINAGE DESIGN (E.O. SIZE AND LOCATION OF ROADS, PIPES, RESTRICTORS, CHANNELS, RETEN-TION FACILITIES, UTILITIES). 2 THE IMPLEMENTATION OF THIS ESC PLAN AND THE CONSTRUCTION, MAINTENANCE, REPLACEMENT, AND UPGRAD-ING OF THESE ESC BMPS IS THE RESPONSIBILITY OF THE APPUCANT UNTIL ALL CONSTRUCTION IS COMPLETED AND APPROVED AND VEGETATION/LANDSCAPING IS ESTABLISHED. 3.CLEARLY FLAG THE BOUNDARIES OF THE CLEARING LIMITS SHOWN ON THIS PLAN IN THE FIELD PRIOR TO CONSTRUCTION. DURING THE CONSTRUCTION PERIOD O DISTURBANCE BEYOND THE FLAGGED CLEARING LIMITS S NHALL BE PERMITTED. THE FLAGGING SHALL BE MAINTAINED BY THE APPLICANT FOR THE DURATION OF CONSTRUCTION. 4, CONSTRUCT THE ESC BMPS SHOWN ON THIS PLAN IN CONJUNCTION WITH ALL CLEARING AND GRADING ACTIVITIES, AND IN SUCH A MANNER AS TO ENSURE THAT SEDIMENT AND SEDIMENT LADEN WATER DO NOT ENTER THE DRAINAGE SYSTEM, ROADWAYS, OR VIOLATE APPLICABLE WATER STANDARDS. 5. THE ESC BMPS SHOWN ON THIS PLAN ARE THE MINIMUM REQUIREMENTS FOR ANTICIPATED SITE CONDITIONS. DURING THE CONSTRUCTION PERIOD, UPGRADE THESE ESC BMPS AS NEEDED FOR UNEXPECTED STORM EVENTS AND TO ENSURE THAT SEDIMENT AND SEDIMENT -LADEN WATER DO NOT LEAVE THE SITE. 6. THE APPLICANT SHALL INSPECT THE ESC BMPS DAILY AND MAINTAIN THEM AS NECESSARY TO ENSURE THEIR CON-TINUED FUNCTIONING. 7. INSPECT AND MAINTAIN THE ESC BMPS ON INACTIVE SITES A MINIMUM OF ONCE A MONTH OR WITHIN THE 48 HOURS FOLLOWING A MAJOR STORM EVENT (I.E A 24-HOUR STORM EVENT WITH A 10 -YR OR GREATER RECURRENCE INTERVAL). B. AT NO TIME SHALL THE SEDIMENT EXCEED 60 -PERCENT OF THE SUMP DEPTH OR HAVE LESS THAN &INCHES OF CLEARANCE FROM THE SEDIMENT SURFACE TO THEINVERT LL THE LOWEST PIPE. ALL CATCH BASINS AND CON-VEYANCE LINES SHALL BE CLEANED PRIOR WPAVING.THECLEANING OPERATION SHALL NOT FLUSH SEDIMENT LADEN WATER INTO THE DOWNSTREAM SYSTEM. 9. INSTALL STABILIZED CONSTRUCTION ENTRANCES AT THE BEGINNING OF CONSTRUCTION AND MAINTAINED FOR THE DUR-ATION OF THE PROJECT. ADDITIONAL MEASURES MAY BE REQUIRED TO ENSURE THAT ALL PAVED AREAS ARE KEPT CLEAN FOR THE DURATION OF THE PROJECT. IN GENERAL ALL BMP'S SHALL BE CHECKED WEEKLY AND AFTER A SIGNIFICANT RAINFALL (MORE THANLL BE CHECKED N24 HOURS). THE FOLLOWING ITEMS SHALL BE CHECKED IN PARTICULAR: 1. SEDIMENT BASINS SHALL BE CLEANED OUT WHEN THE LEVEL OF SEDIMENT REACHE51-12-FEET FROM THE TOP OF THE RISER PIPE. 2. GRAVEL AROUND THE RISER PI PE SHALL BE CHECKED REGULARLY FOR SEDIMENT BUILDUP WHICH WOULD RESTRICT DRAINAGE. IF THE GRAVEL BECOMES CLOGGED WITH SILT, IT SHALL BE REPLACED. 3. DNERSION DIKES AND SWALES SHALL BE CHECKED FOR BLOCKAGE AND DAMAGE ON A REGULAR BASIS. WATER SHALL MOVE FREELY BEHIND DIKES AND IN SWALES AT ALL TIMES, 4. PIPE SLOPE DRAINS SHALL BE CHECKED FOR STABILITY, NO UNDERMINING OF TXE PIPE SHALL BE ALLOWED. 5. FILTER FENCE SHALL BE CHECKED REGULARLY FOR UNDERMINING AND SEDIMENT BUILDUP, SEDIMENT SHALL BE REMOVED ONCE IT REACHES DEPTH OF OCT. FM 6. EROSION CONTROL BLANKETS SHALL BE CHECKED FOR STABILITY, BLANKETS SHALL BE HELD IN PLACE AND HAVE GOOD CONTACT WITH THE FILL SLOPE AT ALL TIMES, 7. ALL SEEDED AND SODDED AREAS ESPECIAL FILL LL SLOPES SHALL BE CHECKED REGULARLYAL MAKE SURE VEGETATIVE COVERAGE IS COMPLETE. AREAS SHALL BE RESEEDED AND FERTILIZED AS NEEDED. 8. TRACKING OF MUD OFFSITE WILL NOT BE ALLOWED. IF EXCESSIVE MUD IS TRACKED OFF SITE, IT SHALL BE CLEANED WITH A STREET SWEEPER. FURTXER TRACKING SHALL THEN BE PREVENTED BY WASHING TRUCK TIRES OR SWEEPING CONTINUOUSLY. 12" MIN. DEPTH �C/ GEOTEXTILE FABRIC PER BMP C705 15' MIN. PROVIDE FULL WIDTH OF QUARRY SPALLS INGRESS / EGRESS AREA STABILIZED CONSTRUCTION ENTRANCE (BMP C 105)IN N.T.S. STABILIZED CONSTRUCTION ENTRANCE NOTES: (BMP C1 O! 1. NIAYERIAL SHALL BE 41NCH TO S INCH QUARRY SPALLS AND MAY BE TdP-DRESSED WITH 11NCH T03INCH ROCK (STATE STANDARD 2. THE ROCK PAD SHALL BE AT LEAST 12 INCHES THICK AND 100 FEET LONG. WIDTH SHALL BE THE FULL WIDTH OF THE VEHICLE INGRESS AND EGRESS AREA SMALLER PADS MAY BE APPROVED FOR SINGLE-FAMILY RESIDENTIAL AND SMALL COMMERCIAL SITES. 3. ADDITIONAL ROCK SHALL BE ADDED PERIODICALLY TO MAINTAIN PROPER fUNC710N OF THE PAD, 4. IF THE PAD DOES NOT ADEQUATELY REMOVE THE MUD FROM THE VEHICLE WHEELS, THE WHEELS SHALL BE HOSED OFF BEFORE THE VEHICLE ENITERS A PAVED STREET. THE WASHING SHALL BE DONE ON AN AREA COVERED WITH CRUSHED ROCK AND WASH WATER SHALL DRAIN 70 A SEDIMENT RETENTION FACILITY OR THROUGH A SILT FENCE. 0 0 Z F z S w APPROVED FOR CONSTRUCTION L BY: DATE: gGENCY NO. 2020.0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM SHEET: 4 OF 17 EJdgN19-W Qf 19-035/CDs APPROVAL EXPIRES: INDEX: 19-035 ec.2)wg JOB: 19-035 0 ik lV 1. FILTER FABRIC SHALL BE PURCHASED IN A CONTINUOUS ROLL CUT TO THE LENGTH OF THE BARRIER 70 AVOID USE OF JOINTS, WHEN JOINTS ARE NECESSARY, FILTER CLOTH SHALL BE SPLICED TOGETHER ONLY AT A SUPPORT POST, WITH A MINIMUM 8 -INCH OVERLAP, AND SECURELY FASTENED AT BOTH ENDS TO POST, 2. POSTS SHALL BE SPACED A MAXIMUM OF 6 FEET APART AND DRIVEN SECURELY INTO THE GROUND (MINIMUM OF 12 INCHES), 3. ATRENCH SHALL BE EXCAVATED APPROXIMATELY 4 INCHES WIDE AND 4 INCHES DEEP ALONG THE UNE OF POSTS AND UPSLOPE FROM THE BARRIER. 4. WHEN STANDARD STRENGTH FILTER FABRIC IS USED, A WIRE MESH SUPPORT FENCE SHALL BE FASTENED SECURELY TO THE UPSLOPE SIDE OF THE POSTS USING HEAVY-DUTY WIRE STAPLES AT LEAST 1 INCH LONG, TIE WIRES OR HOG RINGS. THE WIRE SHALL EXTEND INTO THE TRENCH A MINIMUM OF 41NCHES AND SHALL NOT EXTEND MORE THAN 241NCHESABOVETHE ORIGINAL GROUND SURFACE. 5. THE STANDARD STRENGTH FILTER FABRIC SHALL BE STAPLED OR WIRED TO THE FENCE, AND 20 INCHES OF THE FABRIC SHALL BE EXTEND ED INTO THE TRENCH. THE FABRIC SHALL NOT EXTEND MORE THAN 24 INCHES ABOVE THE ORIGINAL GROUND SURFACE. FILTER FABRIC SHALL NOT BE STAPLED TO EXISTING TREES. e. WHEN EXTRA -STRENGTH FILTER FABRIC AND CLOSER POST SPACING IS USED, THE WIRE MESH SUPPORT FENCE MAYBE ELIMINATED. IN SUCH A CASE, THE FILTER FABRIC IS STAPLED OR WIRED DIRECTLY TO THE POSTS WITH ALL OTHER PROVISIONS OF ABOVE NOTES APPLYING, 7. FILTER FABRIC FENCES SHALL NOT BE REMOVED BEFORE THE UPSLOPE AREA HAS BEEN PERMANENTLY STABILIZED, 6, FILTER FABRIC FENCES SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALLAND AT LEAST DAILY DURING PROLONGED RAINFALL. ANY REQUIRED REPAIRS SHALL BE MADE IMMEDIATELY. 1. APPROVAL OF THIS EROSIOWSEDIMENTATION CONTROL (ESC) PLAN DOES NOT CONSTITUTE AN APPROVAL OF PERMANENT ROAD OR DRAINAGE DESIGN (E.O. SIZE AND LOCATION OF ROADS, PIPES, RESTRICTORS, CHANNELS, RETEN-TION FACILITIES, UTILITIES). 2 THE IMPLEMENTATION OF THIS ESC PLAN AND THE CONSTRUCTION, MAINTENANCE, REPLACEMENT, AND UPGRAD-ING OF THESE ESC BMPS IS THE RESPONSIBILITY OF THE APPUCANT UNTIL ALL CONSTRUCTION IS COMPLETED AND APPROVED AND VEGETATION/LANDSCAPING IS ESTABLISHED. 3.CLEARLY FLAG THE BOUNDARIES OF THE CLEARING LIMITS SHOWN ON THIS PLAN IN THE FIELD PRIOR TO CONSTRUCTION. DURING THE CONSTRUCTION PERIOD O DISTURBANCE BEYOND THE FLAGGED CLEARING LIMITS S NHALL BE PERMITTED. THE FLAGGING SHALL BE MAINTAINED BY THE APPLICANT FOR THE DURATION OF CONSTRUCTION. 4, CONSTRUCT THE ESC BMPS SHOWN ON THIS PLAN IN CONJUNCTION WITH ALL CLEARING AND GRADING ACTIVITIES, AND IN SUCH A MANNER AS TO ENSURE THAT SEDIMENT AND SEDIMENT LADEN WATER DO NOT ENTER THE DRAINAGE SYSTEM, ROADWAYS, OR VIOLATE APPLICABLE WATER STANDARDS. 5. THE ESC BMPS SHOWN ON THIS PLAN ARE THE MINIMUM REQUIREMENTS FOR ANTICIPATED SITE CONDITIONS. DURING THE CONSTRUCTION PERIOD, UPGRADE THESE ESC BMPS AS NEEDED FOR UNEXPECTED STORM EVENTS AND TO ENSURE THAT SEDIMENT AND SEDIMENT -LADEN WATER DO NOT LEAVE THE SITE. 6. THE APPLICANT SHALL INSPECT THE ESC BMPS DAILY AND MAINTAIN THEM AS NECESSARY TO ENSURE THEIR CON-TINUED FUNCTIONING. 7. INSPECT AND MAINTAIN THE ESC BMPS ON INACTIVE SITES A MINIMUM OF ONCE A MONTH OR WITHIN THE 48 HOURS FOLLOWING A MAJOR STORM EVENT (I.E A 24-HOUR STORM EVENT WITH A 10 -YR OR GREATER RECURRENCE INTERVAL). B. AT NO TIME SHALL THE SEDIMENT EXCEED 60 -PERCENT OF THE SUMP DEPTH OR HAVE LESS THAN &INCHES OF CLEARANCE FROM THE SEDIMENT SURFACE TO THEINVERT LL THE LOWEST PIPE. ALL CATCH BASINS AND CON-VEYANCE LINES SHALL BE CLEANED PRIOR WPAVING.THECLEANING OPERATION SHALL NOT FLUSH SEDIMENT LADEN WATER INTO THE DOWNSTREAM SYSTEM. 9. INSTALL STABILIZED CONSTRUCTION ENTRANCES AT THE BEGINNING OF CONSTRUCTION AND MAINTAINED FOR THE DUR-ATION OF THE PROJECT. ADDITIONAL MEASURES MAY BE REQUIRED TO ENSURE THAT ALL PAVED AREAS ARE KEPT CLEAN FOR THE DURATION OF THE PROJECT. IN GENERAL ALL BMP'S SHALL BE CHECKED WEEKLY AND AFTER A SIGNIFICANT RAINFALL (MORE THANLL BE CHECKED N24 HOURS). THE FOLLOWING ITEMS SHALL BE CHECKED IN PARTICULAR: 1. SEDIMENT BASINS SHALL BE CLEANED OUT WHEN THE LEVEL OF SEDIMENT REACHE51-12-FEET FROM THE TOP OF THE RISER PIPE. 2. GRAVEL AROUND THE RISER PI PE SHALL BE CHECKED REGULARLY FOR SEDIMENT BUILDUP WHICH WOULD RESTRICT DRAINAGE. IF THE GRAVEL BECOMES CLOGGED WITH SILT, IT SHALL BE REPLACED. 3. DNERSION DIKES AND SWALES SHALL BE CHECKED FOR BLOCKAGE AND DAMAGE ON A REGULAR BASIS. WATER SHALL MOVE FREELY BEHIND DIKES AND IN SWALES AT ALL TIMES, 4. PIPE SLOPE DRAINS SHALL BE CHECKED FOR STABILITY, NO UNDERMINING OF TXE PIPE SHALL BE ALLOWED. 5. FILTER FENCE SHALL BE CHECKED REGULARLY FOR UNDERMINING AND SEDIMENT BUILDUP, SEDIMENT SHALL BE REMOVED ONCE IT REACHES DEPTH OF OCT. FM 6. EROSION CONTROL BLANKETS SHALL BE CHECKED FOR STABILITY, BLANKETS SHALL BE HELD IN PLACE AND HAVE GOOD CONTACT WITH THE FILL SLOPE AT ALL TIMES, 7. ALL SEEDED AND SODDED AREAS ESPECIAL FILL LL SLOPES SHALL BE CHECKED REGULARLYAL MAKE SURE VEGETATIVE COVERAGE IS COMPLETE. AREAS SHALL BE RESEEDED AND FERTILIZED AS NEEDED. 8. TRACKING OF MUD OFFSITE WILL NOT BE ALLOWED. IF EXCESSIVE MUD IS TRACKED OFF SITE, IT SHALL BE CLEANED WITH A STREET SWEEPER. FURTXER TRACKING SHALL THEN BE PREVENTED BY WASHING TRUCK TIRES OR SWEEPING CONTINUOUSLY. 12" MIN. DEPTH �C/ GEOTEXTILE FABRIC PER BMP C705 15' MIN. PROVIDE FULL WIDTH OF QUARRY SPALLS INGRESS / EGRESS AREA STABILIZED CONSTRUCTION ENTRANCE (BMP C 105)IN N.T.S. STABILIZED CONSTRUCTION ENTRANCE NOTES: (BMP C1 O! 1. NIAYERIAL SHALL BE 41NCH TO S INCH QUARRY SPALLS AND MAY BE TdP-DRESSED WITH 11NCH T03INCH ROCK (STATE STANDARD 2. THE ROCK PAD SHALL BE AT LEAST 12 INCHES THICK AND 100 FEET LONG. WIDTH SHALL BE THE FULL WIDTH OF THE VEHICLE INGRESS AND EGRESS AREA SMALLER PADS MAY BE APPROVED FOR SINGLE-FAMILY RESIDENTIAL AND SMALL COMMERCIAL SITES. 3. ADDITIONAL ROCK SHALL BE ADDED PERIODICALLY TO MAINTAIN PROPER fUNC710N OF THE PAD, 4. IF THE PAD DOES NOT ADEQUATELY REMOVE THE MUD FROM THE VEHICLE WHEELS, THE WHEELS SHALL BE HOSED OFF BEFORE THE VEHICLE ENITERS A PAVED STREET. THE WASHING SHALL BE DONE ON AN AREA COVERED WITH CRUSHED ROCK AND WASH WATER SHALL DRAIN 70 A SEDIMENT RETENTION FACILITY OR THROUGH A SILT FENCE. 0 0 Z F z S w APPROVED FOR CONSTRUCTION L BY: DATE: gGENCY NO. 2020.0004 DEVELOPMENT REVIEW ENGINEER, CITY OF YELM SHEET: 4 OF 17 EJdgN19-W Qf 19-035/CDs APPROVAL EXPIRES: INDEX: 19-035 ec.2)wg JOB: 19-035 0 ik D. Site Inspection Form The results of each inspection shall be summarized in an inspection report or checklist that is entered into or attached to the site log book. It is suggested that the inspection report or checklist be included in this appendix to keep monitoring and inspection information in one document, but this is optional. However, it is mandatory that this SWPPP and the site inspection forms be kept onsite at all times during construction, and that inspections be performed and documented as outlined below. At a minimum, each inspection report or checklist shall include: a. Inspection date/times b. Weather information: general conditions during inspection, approximate amount of precipitation since the last inspection, and approximate amount of precipitation within the last 24 hours. c. A summary or list of all BMPs that have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: I ocations of BMPs inspected, ii. locations of BMPs that need maintenance, the reason maintenance is needed, iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reasons) why e. A description of stormwater discharged from the site. The presence of suspended sediment, turbid water, discoloration, and/or oil sheen shall be noted, as applicable. f. A description of any water quality monitoring performed during inspection, and the results of that monitoring. g. General comments and notes, including a brief description of any BMP r repairs, maintenance or installations made as a result of the inspection. h. A statement that, in the judgment of the person conducting the site I nspection, the site is either in compliance or out of compliance with the terms and conditions of the SWPPP and the NPDES permit. If the site I nspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. i. Name, title, and signature of person conducting the site inspection; and the following statement: "I certify under penalty of law that this report is true, accurate, and complete, to the best of my knowledge and belief". When the site inspection indicates that the site is not in compliance with any terms and conditions of the NPDES permit, the Permittee shall take immediate action(s) to: stop, contain, and clean up the unauthorized discharges, or otherwise stop the noncompliance; correct the problem(s); implement appropriate Best Management Practices (BMPs), and/or conduct maintenance of existing BMPs; and achieve compliance with all applicable standards and permit conditions. In addition, if the noncompliance causes a threat to human health or the environment, the Permittee shall comply with the Noncompliance Notification requirements in Special Condition S5.F of the permit. Page X35 Project Name: Inspector Name: Date: Inspection Type: Weather Precipitation Site Inspection Form General Information Title: CESCL # Time: ❑ After a rain event ❑ Weekly ❑ Turbidity/transparency benchmark exceedance ❑ Other Since last inspection Description of General Site Conditions: Page X36 In last 24 hours Element 1: Mark Clearing Limits BMP: Location BMP: Location Inspected Functioning Y N Inspected Functioning Element 2: Establish Construction Access BMP: Inspected Functioning Location Y N Inspection of BMPs Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action BMP: Location Inspected Functioning Y N Element 3: Control Flow Rates BMP: Inspected Functioning Location Y N BMP: Inspected Functioning Location Y N Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Element 4: Install Sediment Controls BMP: Location Inspected Functioning Y N BMP: Inspected Location Y N BMP: Functioning Inspected Functioning Location Y N BMP: Inspected Functioning Location Y N Page X39 Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action BMP: Location Inspected Y N Functioning Element 5: Stabilize Soils BMP: Inspected Functioning Location Y N BMP: Inspected Functioning Location Y N BMP: Inspected Location Y N Page X40 Functioning Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Location Inspected Functioning Y N Element 6: Protect Slopes BMP: Inspected Functioning Location Y N BMP: Inspected Location Y N BMP: Functioning Inspected Functioning Location Y N Page X41 Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Element 7: Protect Drain Inlets BMP: Inspected Location BMP: Functioning Inspected Functioning Location Y N BMP: Inspected Location Page X42 Functioning Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Element 8: Stabilize Channels and Outlets BMP: Inspected Functioning Location BMP: Location BMP: Location BMP: Location Page X43 Y N Inspected Functioning Y N Inspected Y N Functioning Inspected Functioning Y N Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Element 9: Control Pollutants BMP: Inspected Location BMP: Inspected Location Y N Functioning Functioning Problem/Corrective Action Problem/Corrective Action Element 10: Control Dewatering BMP: Inspected Functioning Location Y N BMP: Inspected Location BMP: Inspected Location Y N Page X45 Functioning Functioning Problem/Corrective Action Problem/Corrective Action Problem/Corrective Action Stormwater Discharges From the Site observed? Problem/Corrective Action Y m Location Turbidity Discoloration Sheen Location Turbidity Discoloration Sheen Page X46 Water Quality Monitoring Was any water quality monitoring conducted? I ❑ I Yes ❑ No If water quality monitoring was conducted, record results here: If water quality monitoring indicated turbidity 250 NTU or greater; or transparency 6 cm or less, was Ecology notified by phone within 24 hrs? ❑ Yes ❑ No If Ecology was notified, indicate the date, time, contact name and phone number below: Date: Time: Contact Name: Phone #: General Comments and Notes Include BMP repairs, maintenance, or installations made as a result of the inspection. Were Photos Taken? ❑ Yes ❑ No If photos taken, describe photos below: Page X47 E. Construction Stormwater General Permit (CSWGP) Issuance Date. Effective Date: Expiration Date. July 11 2019 August 1, 2019 July 31, 2024 Western Washington Phase II Municipal Stormwater Permit National Pollutant Discharge Elimination System and State Waste Discharge General Permit for discharges from Small Municipal Separate Storm Sewers In Western Washington State of Washington Department of Ecology Olympia, WA 98504=7600 In compliance with the provisions of The State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington and The Federal Water Pollution Control Act (The Clean Water Act) Title 33 United States Code, Section 1251 etseq. Untie this Permit expires, is modified, or revoked, Permittees that leave properly obtained coverage under this Permit are authorized to discharge to waters of the State in accordance with the special and general conditions which follow. r K. Bartlett Water Quality Program Manager Department of Ecology This page intentionally left an TABLE OF CONTENTS S1. PERMIT COVERAGE AREA AND PERMITTEES.............................................................................................1 S2. AUTHORIZED DISCHARGES.................................................................................................................................. 5 S3. RESPONSIBILITIES OFPERMITTEES............................................................................................................... 6 S4. COMPLIANCE WITH STANDARDS..................................................................................................................... 7 S5. STORMWATER MANAGEMENT PROGRAM FOR CITIES, TOWNS, AND COUNTIES ...................... 9 S5.C.1 Stormwater Planning.................................................................................................................................11 S5.C.2 Public Education and Outreach.................................................................................................................14 S5. C.3 Public Involvement and Participation. moves@@@ a 9 8 0 9 8 1 9 0 9 a 0 8 1 8 8 a 9 0 9 9 1 a a I a 9 8 1 1 a 0 4 1 1 1 a a 9 9 9 9 9 A 9 9 9 9 9 9 9 9 9 9 a a 0 0 0 0 d a 0 0 0 0 d 9 9 a 0 0 0 9 9 1 d 0 0 0 9 9 d 9 9 0 0 0 0 d d 9 0 a 9 16 S5. C.4 MS4 Mapping and Documentation...........................................................................................................17 55.C.5 Illicit Discharge Detection and Elimination................. @Segel 8886840086864 88644488868 18 S5.C.6 Controlling Runoff from New Development, Redevelopment and Construction Sites .............................22 5.C.7 Operations and Maintenance....................................................................................................................24 5.C.8 Source Control Program for Existing Development..... 0 0 9 0 a d a a 6 9 a 0 a a 0 d 0 a a a a 9 0 0 0 0 a 0 0 0 9 0 0 0 0 0 0 a a 0 0 0 0 a a 0 0 a a 6 0 0 a 0 0 0 0 0 0 1 0 0 0 0 0 a 0 0 0 0 a 0 a a 0 0 a 028 S6. STORMWATER MANAGEMENT PROGRAM FOR SECONDARY PERMITTEES...............................31 S7. COMPLIANCE WITH TOTAL MAXIMUM DAILY LOAD REQUIREMENTS.........................................37 S8. MONITORING AND ASSESSMENT....................................................................................................................38 S9. REPORTING REQUIREMENTS...........................................................................................................................40 GENERAL CONDITIONS......................................................................................................................................................42 DEFINITIONS AND ACRONYMS.......................................................................................................................................49 Western Washington Phase /!Municipal Page i Stormwater Perrnit-August 1, 2019 APPENDICES APPENDIX 1, Minimum Technical Requirements for New Development and Redevelopment APPENDIX 2. Total Maximum Daily Load Requirements APPENDIX 3. Annual Report Questions for Cities, Towns and Counties APPENDIX 4. Annual Report Questions for Secondary Permittees APPENDIX 5, Annual Report Questions for New Permittees APPENDIX 6. Street Waste Disposal APPENDIX 7. Determining Construction Site Damage Transport Potential APPENDIX 8. Businesses and activities that are potential sources of pollutants APPENDIX 9. Stormwater Discharge Monitoring APPENDIX 10. Equivalent programs for runoff controls for new and redevelopment and construction sites APPENDIX 11. Annual contribution amounts for regional monitoring APPENDIX 12. IDDE Reporting data and format Western Washington Phase 1l Municipal Page ii Stormwater Permit -August 1, 2019 S1.A.1 SPECIAL CONDITIONS S1. PERMIT COVERAGE AREA AND PERMITTEES A. Geographic Area of Permit Coverage S1.B,1 This Permit is applicable to owners or operators of regulated small Municipal Separate Storm Sewer Systems (MS4s) located west of the eastern boundaries of the following counties: Whatcom, Skagit, Snohomish, King, Pierce, Lewis, and Skamania. 1. For all cities required to obtain coverage under this Permit, the geographic area of coverage is the entire incorporated area of the city. 2. For all counties required to have coverage under this Permit, the geographic area of coverage is the urbanized areas and urban growth areas associated with permitted cities under the jurisdictional control of the county. The geographic area of coverage also includes any urban growth area contiguous to permitted urbanized areas under the jurisdictional control of the county. 3. For Whatcom County, the geographic area of coverage also includes the unincorporated Birch Bay urban growth area. 4. For Secondary Permittees required to obtain coverage under this Permit, the minimum geographic area of coverage is all areas identified under S1.A.1 and S1.A.2. At the time of permit coverage, the Washington State Department of Ecology (Ecology) may establish a geographic area of coverage specific to an individual Secondary Permittee. 5. All regulated small MS4s owned or operated by the Permittees named in (Z 1.D.2.a(i), and (ii), and S1.D.2.b and located in another city or county area requiring coverage under this Permit, or the Phase 1 Municipal Stormwater Permit or the Eastern Washington Phase 11 Municipal Stormwater Permit, are also covered under this Permit. B. Regulated Small Municipal Separate Storm Sewer Systems (MS4s) All operators of regulated small MS4s are required to apply for and obtain coverage under this Permit or be permitted under a separate individual permit, unless waived or exempted in accordance with condition S1.C. 1. A regulated small MS4: a. Is a "Small MS4" as defined in the Definitions and Acronyms section at the end of this Permit; and b. Is located within, or partially located within, an urbanized area as defined by the latest decennial census conducted by the U.S. Census Bureau, or designated by Ecology pursuant to 40 CFR 123.35(b) or 40 CFR 122.26(f); and c. Discharges stormwater from the MS4 to a surface water of Washington State; and d. Is not eligible for a waiver or exemption under S1. C, below. Western Washington Phase 11 Municipal Page 1 of 56 stormwater Permit -August 1, 2019 51.13.2 S1.C.1 2. All other operators of 1VI34s, including special purpose districts, which meet the criteria for a regulated small MS4 shall obtain coverage under this Permit. Other operators of small MS4s may include, but are not limited to: flood control, or diking and drainage districts; schools, including universities; and correctional facilities that own or operate a small MS4 serving non-agricultural land uses. 3. Any other operators of small MS4s may be required by Ecology to obtain coverage under this Permit or an alternative NPDES permit if Ecology determines the small MS4 is a significant source of pollution to surface waters of the State. Notification of Ecology's determination that permit coverage is required will be through the issuance of an Administrative Order issued in accordance with RCW 90.48. 4. The owner or operator of a regulated small MS4 may obtain coverage under this Permit as a Permittee, Co -Permittee, or Secondary Permittee as defined in S1.D.1, below. S. Pursuant to 40 CFR 122.26(f), any person or organization may petition Ecology to require that additional small MS4s obtain coverage under this Permit. The process for petitioning Ecology is: a. The person or organization shall submit a complete petition in writing to Ecology. A complete petition shall address each of the relevant factors for petitions outlined on Ecology's website. b. In making its determination on the petition, Ecology may request additional information from either the petitioner or the entity that is the subject of the petition. c. Ecology will make a final determination on a complete petition within 180 days of receipt of the petition and inform both the petitioner and the 1034 of the decision, in writing. d. If Ecology's final determination is that the candidate MS4 will be regulated, Ecology VV ill issue an order to the operator of the MS4 requiring them to obtain coverage under this Permit. The order will specify: The geographic area of permit coverage for the MS4. Any modified dates or deadlines for developing and implementing this Permit, as appropriate to the MS4, and for submitting their first annual report. A deadline for the operator of the MS4 to submit a complete Notice of Intent (NOI, provided on Ecology's website) to Ecology. C. Owners and operators of an otherwise regulated small MS4 are not required to obtain coverage under this Permit if: 1. The small MS4 is operated by: a. A federal entity, including any department, agency, or instrumentality of the executive, legislative, and judicial branches of the Federal government of the United States. b. Federally recognized Indian Tribes located within Indian Country, including all trustor restricted lands within the 1873 Survey Area of the Puyallup Tribe of Indians. c. The Washington State Department of Transportation. Western Washington Phase 11 Municipal Page 2 of 56 Stormwater Permit -August 1, 2019 S1.C.2 S1.D.1 2. The portions of the small MS4 located within the census defined urbanized areas) serve a total population of less than 1000 people and a, b, and c, below all apply: a. The small MS4 is not contributing substantially to the pollutant loadings of a physically interconnected MS4 that is regulated by the NPDES stormwater program. b. The discharge of pollutants from the small MS4 has not been identified as a cause of impairment of any water body to which the MS4 discharges. c. In areas where an EPA approved TMDL has been completed, stormwater controls on the MS4 have not been identified as necessary to meet wasteload allocations established in the TMDL that address the pollutant(s) of concern. In determining the total population served, both resident and commuter populations shall be included. For example: • For publicly operated school complexes including universities and colleges, the total population served would include the sum of the average annual student enrollment plus staff. • For flood control, diking, and drainage districts, the total population served would include residential population and any non-residents regularly employed in the areas served by the small MS4. p. Obtaining coverage under this Permit. All operators of regulated small MS4s are required to apply for and obtain coverage in accordance with this Section, unless waived or exempted, in accordance with Section 31.C. 1. Unless otherwise noted, the term "Permittee" shall include a city, town, or county Permittee, New Permittee, Co -Permittee, Secondary Permittee, and New Secondary Permittee as defined below: a. "Permittee" is a city, town, or county owning or operating a regulated small MS4 applying and receiving a permit as a single entity. b. "New Permittee" is a city, town, or county that is subject to the Western Washington Phase 11 Municipal stormwater General Permit and was not subject to the Permit prior to August 1, 2019. c. "Co -Permittee" is any owner or operator of a regulated small MS4 that is applying in a cooperative agreement with at least one other applicant for coverage under this Permit. Co -Permittees own or operate a regulated small MS4 located within or in proximity to another regulated small MS4. d. A "Secondary Permittee" is an operator of a regulated small MS4 that is not a city, town, or county. Secondary Permittees include special purpose districts and other MS4s that meet the criteria for a regulated small MS4 in S1.13, above. e. "New Secondary Permittee" is a Secondary Permittee that is covered under a Municipal stormwater General Permit and was not covered by the Permit prior to August 1, 2019. Western Washington Phase II Municipal Page 3 of 56 stormwater Permit -August 1, 2019 S1.D.2 S1.D.2 2. Operators of regulated small 1034s have submitted, or shall submit, to Ecology either a Notice of Intent (NOI) for Coverage under National Pollutant Discharge Elimination System (NPDES) Municipal Stormwater General Permit or a Duty to Reapply - NOI provided on Ecology's website. a. The following Permittees and Secondary Permittees submitted a Duty to Reapply - NOI to Ecology prior to February 1, 2018: Cities and towns: Aberdeen, Algona, Anacortes, Arlington, Auburn, Bainbridge Island, Battle Ground, Bellevue, Bellingham, Black Diamond, Bonney Lake, Bothell, Bremerton, Brier, Buckley, Burien, Burlington, Camas, Centralia, Clyde Hill, Covington, Des Moines, DuPont, Duvall, Edgewood, Edmonds, Enumclaw, Everett, Federal Way, Ferndale, Fife, Fircrest, Gig Harbor, Granite Falls, Issaquah, Kelso, Kenmore, Kent, Kirkland, Lacey, Lake Forest Park, Lake Stevens, Lakewood, Longview, Lynden, Lynnwood, Maple Valley, Marysville, Medina, Mercer Island, Mill Creek, Milton, Monroe, Mountlake Terrace, Mount Vernon, Mukilteo, Newcastle, Normandy Park, Oak Harbor, Olympia, Orting, Pacific, Port Orchard, Port Angeles, Poulsbo, Puyallup, Redmond, Renton, Sammamish, SeaTac, Sedro- Woolley, Shoreline, Snohomish, Snoqualmie, Steilacoom, Sumner, Tukwila, Tumwater, University Place, Vancouver, Washougal, and Woodinville. Counties: Cowlitz, Kitsap, Thurston, Skagit, and Whatcom. Secondary Permittees: Bainbridge Island School District #303, Bellingham School District, Bellingham Technical College, Cascadia College, Central Kitsap School District, Centralia College, Clark College, Consolidated Diking Improvement District #1 of Cowlitz County, Edmonds Community College, Evergreen College, Highline Community College, Kelso School District, Kent School District, Longview School District, Lower Columbia College, Port of Anacortes, Port of Bellingham, Port of Olympia, Port of Skagit County, Port of Vancouver, Skagit County Drainage District #19, Skagit Valley College, University of Washington Bothell, Washington State University Vancouver, Washington State Department of Enterprise Services (Capitol Campus), Washington Department of Corrections, Western Washington University, and Whatcom Community College. b. Operators of regulated small MS4s have submitted or shall submit to Ecology a "Notice of Intent (NOI) for Coverage under National Pollutant Discharge Elimination System (NPDES) Municipal Stormwater General Permit" provided on Ecology's website before the effective date of this Permit, with the following exceptions: i. Operators of regulated small MS4s located in the City of Shelton, and the Clallam County urban growth area surrounding Port Angeles shall submit a NOI or application to Ecology no later than 30 days after the effective date of this Permit. ii. Operators of regulated small MS4s listed in S1.D.2.a do not need to submit a new application to be covered under this Permit. c. For operators of regulated small MS4s listed in S1.D.2.a, coverage under this Permit is automatic and begins on the effective date of this Permit, unless the operator chooses to opt out of this General Permit. Any operator of a regulated small MS4 that Western Washington Phase ❑Municipal Page 4 of 56 Stormwater Permit -August 1, 2019 S1.D.3 S2.A.2 is opting out of this Permit shall submit an application for an individual MS4 permit in accordance with 40 CFR 122.33(b)(2)(ii) no later than the effective date of this Permit. d. Operators of regulated small MS4s which want to be covered under this Permit as Co - Permittees shall each submit a NOI to Ecology. e, Operators of regulated small MS4s which are relying on another entity to satisfy all of their permit obligations shall submit a NOI to Ecology, f. Operators of small MS4s designated by Ecology pursuant to S1.B.3 of this Permit shall submit a NOI to Ecology within 120 days of receiving notification from Ecology that permit coverage is required. 3. Application Requirements a. For NOIs submitted after the issuance date of this Permit, the applicant shall include a certification that the public notification requirements of WAC 173-226-130(5) have been satisfied. Ecology will notify applicants in writing of their status concerning coverage under this Permit within 90 days of Ecology's receipt of a complete NOI. b. Each Permittee applying as a Co -Permittee shall submit a N01 provided on Ecology's website. The NOI shall clearly identify the areas of the MS4 for which the Co - Permittee is responsible. c. Permittees relying on another entity or entities to satisfy one or more of their permit obligations shall notify Ecology in writing. The notification shall include a summary of the permit obligations that will be carried out by another entity. The summary shall identify the other entity or entities and shall be signed by the other entity or entities. During the term of the Permit, Permittees may terminate or amend shared responsibility arrangements by notifying Ecology, provided this does not alter implementation deadlines. d. Secondary Permittees required to obtain coverage under this Permit, and the Phase 1 Municipal Stormwater Permit or the Eastern Washington Phase 11 Municipal Stormwater Permit, may obtain coverage by submitting a single NOI. S2, AUTHORIZED DISCHARGES A, This Permit authorizes the discharge of stormwater to surface waters and to groundwaters of the State from MS4s owned or operated by each Permittee covered under this Permit, in the geographic area covered pursuant to S1.A. These discharges are subject to the following limitations: 1. Discharges to groundwaters of the State through facilities regulated under the Underground Injection Control (UIC) program, Chapter 173-218 WAC, are not authorized under this Permit. 2. Discharges to groundwaters not subject to regulation under the federal Clean Water Act are authorized in this Permit only under state authorities, Chapter 90.48 RCW, the Water Pollution Control Act. Western Washington Phase //Municipal Page 5 of 56 Stormwater Permit -August 1, 2019 2,B,1 S3.A.2 B. This Permit authorizes discharges of non-stormwater flows to surface waters and to groundwaters of the State from MS4s owned or operated by each Permittee covered under this Permit, in the geographic area covered pursuant to SLA, only under one or more of the following conditions: �. The discharge is authorized by a separate NPDES or State Waste Discharge permit. 2. The discharge is from emergency firefighting activities. 3. The discharge is from another illicit or non-stormwater discharge that is managed by the Permittee as provided in Special Condition S5.C.5 or S6.D.3. These discharges are also subject to the limitations in S2.A.1 and 52.A.2, above. C. This Permit does not relieve entities that cause illicit discharges, including spills of oil or hazardous substances, from responsibilities and liabilities under state and federal laws and regulations pertaining to those discharges. D. Discharges from MS4s constructed after the effective date of this Permit shall receive all applicable state and local permits and use authorizations, including compliance with Chapter 43.21C RCW (the State Environmental Policy Act). E. This Permit does not authorize discharges of stormwater to waters within Indian Country as defined in 18 U.S.C. §1151, or to waters subject to water quality standards of Indian Tribes, including portions of the Puyallup River and other waters on trust or restricted lands within the 1873 Survey Area of the Puyallup Tribe of Indians Reservation, except where authority has been specifically delegated to Ecology by the U.S. Environmental Protection Agency. The exclusion of such discharges from this Permit does not waive any rights the State may have with respect to the regulation of the discharges. S3. RESPONSIBILITIES OF PERMITTEES A. Each Permittee covered under this Permit is responsible for compliance with the terms of this Permit for the regulated small MS4s that they own or operate. Compliance with (1) or (2) below is required as applicable to each Permittee, whether the Permittee has applied for coverage as a Permittee, Co -Permittee, or Secondary Permittee. 1. All city, town, and county Permittees are required to comply with all conditions of this Permit, including any appendices referenced therein, except for Special Condition S6 — Stormwater Management Program for Secondary Permittees. 2. All Secondary Permittees are required to comply with all conditions of this Permit, including any appendices referenced therein, except for Section S5 —stormwater Management Program for Cities, Towns, and Counties and S8 — Monitoring and Assessment. B. Permittees may rely on another entity to satisfy one or more of the requirements of this Permit. Permittees that are relying on another entity to satisfy one or more of their permit obligations remain responsible for permit compliance if the other entity fails to implement permit conditions. Permittees may rely on another entity provided all the requirements of 40 CFR 122.35(a) are satisfied, including but not limited to: Western Washington Phase ?/Municipal Page 6 of 56 stormwater Permit -August 1, 2019 S3.B.1 1. The other entity, in fact, implements the Permit requirements. 2. The other entity agrees to take on responsibility for implementation of the Permit requirement(s) as indicated on the NO]. S4. COMPLIANCE WITH STANDARDS S4•.F.2 A, In accordance with RCW 90.48.520, the discharge of toxicants to waters of the State of Washington which would violate any water quality standard, including toxicant standards, sediment criteria, and dilution zone criteria is prohibited. The required response to such discharges is defined in Section S4.F, below. B. This Permit does not authorize a discharge which would be a violation of Washington State Surface Water Quality Standards (Chapter 173-201A WAC), Groundwater Quality Standards (Chapter 173-200 WAC), Sediment Management Standards (Chapter 173-204 WAC), or human health -based criteria in the National Toxics Rule (40 CFR 131.45). The required response to such discharges is defined in Section S4.F, below. C. The Permittee shall reduce the discharge of pollutants to the Maximum Extent Practicable (MEP). p. The Permittee shall use All Known, Available, and Reasonable methods of prevention, control and Treatment (AKART) to prevent and control pollution of waters of the State of Washington. E. In order to meet the goals of the Clean Water Act, and comply ;+kCAA S4. B, S4.C, and S4. D, each Permittee shall comply with all of the applicable requirements of this Permit as identified in S3 — Responsibilities of Permittees. F. A Permittee remains in compliance with S4 despite any discharges prohibited by S4 .A or S4. B, when the Permittee undertakes the following response toward long-term water quality improvement: 1. A Permittee shall notify Ecology in writing within 30 days of becoming aware, based on credible site-specific information that a discharge from the MS4 owned or operated by the Permittee is causing or contributing to a known or likely violation of Water Quality Standards in the receiving water. Written notification provided under this subsection shall, at a minimum, identify the source of the site-specific information, describe the nature and extent of the known or likely violation in the receiving water, and explain the reasons why the MS4 discharge is believed to be causing or contributing to the problem. For ongoing or continuing violations, a single written notification to Ecology will fulfill this requirement. 2. In the event that Ecology determines, based on a notification provided under S4.F.1 or through any other means, that a discharge from an MS4 owned or operated by the Permittee is causing or contributing to a violation of Water Quality Standards in a receiving water, Ecology will notify the Permittee in writing that an adaptive management response, outlined in S4.F.3, below, is required, unless: Western Washington Phase 1! Municipal Page 7 of 56 Stormwater Permit- August 1, 2019 S4.F.3 S4.F.3 a. Ecology also determines that the violation of Water Quality Standards is already being addressed by a Total Maximum Daily Load (TMDL) or other enforceable water quality cleanup plan; or b. Ecology concludes the MS4 contribution to the violation will be eliminated through implementation of other permit requirements. 3. Adaptive Management Response a. Within 60 days of receiving a notification under S4.F.2, or by an alternative date established by Ecology, the Permittee shall review its Stormwater Management Program (SWMP) and submit a report to Ecology. The report shall include: I. A description of the operational and/or structural BMPs that are currently being implemented to prevent or reduce any pollutants that are causing or contributing to the violation of Water Quality Standards, including a qualitative assessment of the effectiveness of each Best Management Practice (BMP). ii. A description of potential additional operational and/or structural BMPs that will or may be implemented in order to apply AKART on a site-specific basis to prevent or reduce any pollutants that are causing or contributing to the violation of Water Quality Standards. iii. A description of the potential monitoring or other assessment and evaluation efforts that will or may be implemented to monitor, assess, or evaluate the effectiveness of the additional BMPs. iv. A schedule for implementing the additional BMPs including, as appropriate: funding, training, purchasing, construction, monitoring, and other assessment and evaluation components of implementation. b. Ecology will, in writing, acknowledge receipt of the report within a reasonable time U"d notify the Permittee when it expects to complete its review of the report. Ecology will either approve the additional BMPs and implementation schedule or require the Permittee to modify the report as needed to meet AKART on a site-specific basis. If modifications are required, Ecology will specify a reasonable time frame in which the Permittee shall submit and Ecology will review the revised report. c. The Permittee shall implement the additional BMPs, pursuant to the schedule approved by Ecology, beginning immediately upon receipt of written notification of approval. d. The Permittee shall include with each subsequent annual report a summary of the status of implementation and the results of any monitoring, assessment or evaluation efforts conducted during the reporting period. If, based on the information provided under this subsection, Ecology determines that modification of the BMPs or implementation schedule is necessary to meet AKART on a site-specific basis, the Permittee shall make such modifications as Ecology directs. In the event there are ongoing violations of water quality standards despite the implementation of the BMP approach of this Section, the Permittee may be subject to compliance schedules to Western Washington Phase ❑Municipal Page 8 of 56 Stormwater Permit- August 1, 2019 S4.G.1 S5.A.2 eliminate the violation under WAC 173-201A-510(4) and WAC 173-226480 or other enforcement orders as Ecology deems appropriate during the term of this Permit. e. A TMDL or other enforceable water quality cleanup plan that has been approved and is being implemented to address the MS4's contribution to the Water Quality Standards violation supersedes and terminates the S4.F.3 implementation plan. f. Provided the Permittee is implementing the approved adaptive management response under this Section, the Permittee remains in compliance with Special Condition S4, despite any on-going violations of Water Quality Standards identified under S4.A or B, above. g. The adaptive management process provided under Section S4.F is not intended to create a shield for the Permittee from any liability it may face under 42 U.S.C. 9601 et seq. or Chapter 70.105D RCW. G. Ecology may modify or revoke and reissue this General Permit in accordance with G14 — General Permit Modification and Revocation, if Ecology becomes aware of additional control measures, management practices, or other actions beyond what is required in this Permit that are necessary to: 1. Reduce the discharge of pollutants to the MEP, 2. Comply with the state AKART requirements, or 3. Control the discharge of toxicants to waters of the State of Washington. SS. STORMWATER MANAGEMENT PROGRAM FOR CITIES, TOWNS, AND COUNTIES A. Each Permittee shall develop and implement a Stormwater Management Program (SWMP). A SWMP is a set of actions and actives comprising the components listed in S5 and any additional actions necessary, to meet the requirements of applicable TMDLs pursuant to S7 — Compliance with Total Maximum Daily Load Requirements and S8 — Monitoring and Assessment. This Section applies to all cities, towns, and counties covered under this Permit (termed as "Permittee," including cities, towns, and counties that are Co -Permittees). New Permittees subject to this Permit, as described in S1.D.1.b, shall fully meet the requirements in S5 as modified in footnotes below, or as specified in an alternate schedule as a condition of coverage by Ecology. Permittees obtaining coverage after the issuance date of this Permit shall fully meet the requirements in S5 as specified in an alternate schedule as a condition of coverage by Ecology. 1. At a minimum, the Permittee 's SWMP shall be implemented throughout the geographic area subject to this Permit as described in S1.A.1 2. Each Permittee shall prepare written documentation of the SWMP, called the SWMP Plan. The SWMP Plan shall be organized according to the program components in S5.0 or a 1 New Permittees shall fully develop and implement the SWMP in accordance with the schedules contained in this Section no later than February 2, 2024. Western Washington Phase I/ Municipal Page 9 of 56 Stormwater Permit- August 1, 2019 5,A.2 S5.A.5 format approved by Ecology, and shall be updated at least annually for submittal with the Permittee's annual reports to Ecology (see S9 — Reporting Requirements), The SWMP Plan shall be written to inform the public of the planned SWMP activities for the upcoming calendar year, and shall include a description of: aI Planned activities for each of the program components included in S5.C. b. Any additional planned actions to meet the requirements of applicable TMDLs pursuant to S7— Compliance with Total Maximum Daily Load Requirements. c. Any additional planned actions to meet the requirements of S8 —Monitoring and Assessment. 3, The SWMP shall include an ongoing program for gathering, tracking, maintaining, and using information to evaluate SWMP development, implementation, and permit compliance and to set priorities. a. Each Permittee shall track the cost or estimated cost of development and implementation of each component of the SWMP.'This information shall be provided to Ecology upon request. b. Each Permittee shall track the number of inspections, follow-up actions as a result of inspections, official enforcement actions and types of public education activities as required by the respective program component. This information shall be included in the annual report. 4. Permittees shall continue implementation of existing stormwater management programs until they begin implementation of the updated stormwater management program in accordance with the terms of this Permit, including implementation schedules. 5. Coordination among Permittees a. Coordination among entities covered under municipal stormwater NPDES permits maY be necessary to comply with certain conditions of the SWMP. The SWMP shall include, when needed, coordination mechanisms among entities covered under a municipal stormwater NPDES permit to encourage coordinated stormwater-related policies, programs and projects within adjoining or shared areas, including: Coordination mechanisms clarifying roles and responsibilities for the control of pollutants between physically interconnected MS4s covered by a municipal stormwater permit. Coordinating stormwater management activities for shared water bodies, or watersheds among Permittees to avoid conflicting plans, policies, and regulations. b. The SWMP shall include coordination mechanisms among departments within each jurisdiction to eliminate barriers to compliance with the terms of this Permit. Permittees shall include a written description of internal coordination mechanisms in the Annual Report due no later than March 31, 2021. z New Permittees shall begin implementing the requirements of S5.A.3.a, no later than August 1, 2021. Western Washington Phase // Municipal Page 10 of 56 stormwater Permit -August 1, 2019 S5.C.1 S5.C.1 13. The SWMP shall be designed to reduce the discharge of pollutants from regulated small 1054s to the MEP, meet state AKART requirements, and protect water quality. C. The SWMP shall include the components listed below. To the extent allowable under state or federal law, all components are mandatory for city, town, or county Permittees covered under this Permit. 1, Stormwater planning Each Permittee shall implement a Stormwater Planning program to inform and assist in the development of policies and strategies as water quality management tools to protect receiving waters. The minimum performance measures are: a. By August 1, 2020, each Permittee shall convene an inter -disciplinary team to inform and assist in the development, progress, and influence of this program. b. Coordination with long-range plan updates. Each Permittee shall describe how Stormwater management needs and protection/improvement of receiving water health are (or are not) informing the planning update processes and influencing policies and implementation strategies in their jurisdiction. The report shall describe the water quality and watershed protection policies, strategies, codes, and other measures intended to protect and improve local receiving water health through planning, or taking into account Stormwater management needs or limitations. (a) On or before March 31, 2021, the Permittee shall respond to the series of Stormwater Planning Annual Report questions to describe how anticipated stormwater impacts on water quality were addressed, if at all, during the 2013-2019 permit term in updates to the Comprehensive Plan (or equivalent) and in other locally initiated or state -mandated, long-range land use plans that are used to accommodate growth or transportation. (b) On or before January 1, 2023, the Permittee shall submit a report responding to the same questions included in (a), above, to describe how water quality is being addressed, if at all, during this permit term in updates to the Comprehensive Plan (or equivalent) and in other locally initiated or state -mandated, long-range land use plans that are used to accommodate growth or transportation. c. Low impact development code -related requirements. I. Permittees shall continue to require LID Principles and LID BMPs when updating, revising, and developing new local development -related codes, rules, standards, or other enforceable documents, as needed. The intent shall be to make LID the preferred and commonly -used approach to site development. The local development -related codes, rules, standards, or other enforceable documents shall be designed to minimize impervious surfaces, native vegetation loss, and stormwater runoff in all types of development situations, where feasible. Western Washington Phase T/ Municipal Page 11 of 56 Stormwater Permit -August 1, 2019 SS. C.1 SS. C.1 (a) Annually, each Permittee shall assess and document any newly identified administrative or regulatory barriers to implementation of LID Principles or LID BMPs since local codes were updated in accordance with the 2013 Permit, and the measures developed to address the barriers. If applicable, the report shall describe mechanisms adopted to encourage or require implementation of LID principles or LID BMPs. By December 31, 2023, New Permittees shall review, revise, and make effective their local development -related codes, rules, standards, or other enforceable documents to incorporate and require LID principles and LID BMPs. New Permittees shall conduct a similar review and revision process, and consider the range of issues, outlined in the following document: Integrating LID into Local Codes: A Guidebook for Local Governments (Puget Sound Partnership, 2012). New Permittees shall submit a summary of the results of the review and revision process with the annual report due no later than March 31, 2024. This summary shall be in the required format described in Appendix 5 and include, at a minimum, a list of the participants (job title, brief job description, and department represented), the codes, rules, standards, and other enforceable documents reviewed, and the revisions made to those documents which incorporate and require LID principles and LID BMPs. The summary shall include existing requirements for LID principles and LID BMPs in development -related codes. The summary must be organized as follows: (a) Measures to minimize impervious surfaces. (b) Measures to minimize loss of native vegetation. (c) Other measures to minimize stormwater runoff. d. Stormwater Management Action Planning' (SMAP). Permittees shall conduct a similar process and consider the range of issues outlined in the Stormwater Management Action Planning Guidance (Ecology, 2019; Publication 19-10-010). Permittees may rely on another jurisdiction to meet all or part of SMAP requirements at a watershed - scale, provided a SMAP is completed for at least one priority catchment located within the Permittee's jurisdiction. Receiving Water Assessment. Permittees shall document and assess existing information related to their local receiving waters and contributing area conditions to identify which receiving waters are most likely to benefit from stormwater management planning. By March 31, 2022, Permittees shall submit a watershed inventory and include a brief description of the relative conditions of the receiving waters and the contributing areas. The watershed inventory shall be submitted as a table with each receiving water name, its total watershed area, the percent of the total watershed area that is in the Permittee's jurisdiction, and the findings of the stormwater management influence assessment for each basin. Indicate which 3 New Permittees are exempt from S5.C.1.d, for this permit term. Western Washington Phase ❑Municipal Page 12 of 56 stormwater Permit -August 1, 2019 S5.C.1 S5.C.1 receiving waters will be included in the S5.C.1.d.ii prioritization process. Include a map of the delineated basins with references to the watershed inventory table. (a) Identify which basins are expected to have a relatively low Stormwater Management Influence for SMAP. See the guidance document for definition and description of this assessment. Basins having relatively low expected Stormwater Management Influence for SMAP do not need to be included in S5.C.lade ikiii. ii. Receiving Water Prioritization. Informed by the assessment of receiving water conditions in (i), above, and other local and regional information, Permittees shall develop and implement a prioritization method and process to determine which receiving waters will receive the most benefit from implementation of stormwater facility retrofits, tailored implementation of SWMP actions, and other land/development management actions (different than the existing new and redevelopment requirements). The retrofits and actions shall be designed to: 1) conserve, protect, or restore receiving waters through stormwater and land management strategies that act as water quality management tools, 2) reduce pollutant loading, and 3) address hydrologic impacts from existing development as well as planned for and expected future buildout conditions. No later than June 30, 2022, document the prioritized and ranked list of receiving waters. (a) The Permittee shall document the priority ranking process used to identify high priority receiving waters. The Permittee may reference existing local watershed management plan(s) as source(s) of information or rationale for the prioritization. (b) The ranking process shall include the identification of high priority catchment area(s) for focus of the Stormwater Management Action Plan (SMAP) in (iii), below. Stormwater Management Action Plan (SMAP). No later than March 31, 2023, Permittees shall develop a SMAP for at least one high priority catchment area from (ii), above, that identifies all of the following: (a) A description of the stormwater facility retrofits needed for the area, including the BMP types and preferred locations. (b) Land management/development strategies and/or actions identified for water quality management. (c) Targeted, enhanced, or customized implementation of stormwater management actions related to permit sections within S5, including: • IDDE field screening, • Prioritization of Source Control inspections, • O&M inspections or enhanced maintenance, or • Public Education and Outreach behavior change programs. Western Washington Phase 11 Municipal Page 13 of 56 Stormwater Permit -August 1, 2019 S5.C.2 S5.C.2 Identified actions shall support other specifically identified stormwater management strategies and actions for the basin overall, or for the catchment area in particular. (d) If applicable, idencation of changes needed to local long-range plans, to address SMAP priorities. (e) A proposed implementation schedule and budget sources for: • Short-term actions (i. e., actions to be accomplished within six years), and • Long-term actions (i.e., actions to be accomplished within seven to 20 years). (f) A process and schedule to provide future assessment and feedback to improve the planning process and implementation of procedures or projects. 2. Public Education and Outreach The SWMP shall include an education and outreach program designed to: • Build general awareness about methods to address and reduce impacts from stormwater runoff. • Effect behavior change to reduce or eliminate behaviors and practices that cause or contribute to adverse stormwater impacts. • Create stewardship opportunities that encourages community engagement in addressing the impacts from stormwater runoff. Permittees may choose to meet these requirements individually or as a member of a regional group. Regional collaboration on general awareness or behavior change programs, or both, includes Permittees developing a consistent message, determining best methods for communicating the message, and when appropriate, creating strategies to effect behavior change. If a Permittee chooses to adopt one or more elements of a regional program, the Permittee should participate in the regional group and shall implement the adopted element(s) of the regional program in the local jurisdiction. The minimum performance measures are: a. Each Permittee shall implement an education and outreach program forthe area served by the MS4. The program design shall be based on local water quality information and target audience characteristics to identify high priority target audiences, subject areas, and/or BMPs. Based on the target audience's demographic, the Permittee shall consider delivering its selected messages in language(s) other than English, as appropriate to the target audience. 4 General awareness. To build general awareness, Permittees shall annually select at a minimum one target audience and one subject area from either (a) or (b): (a) Target audiences: General public (including overburdened communities, or school age children) or businesses (including home-based, or mobile businesses). Subject areas: New Permittees shall begin implementing the requirements of S5.C.2 no later than August 1, 2021. Western Washington Phase ❑Municipal Page 14 of 56 Stonnwater Permit -August 1, 2019 5.C,2 S5.C.2 • General impacts of stormwater on surface waters, including impacts from impervious surfaces. • Low impact development (LID) principles and LID BMPs. (b) Target audiences: Engineers, contractors, developers, or land use planners. Subject areas: • Technical standards for stormwater site and erosion control plans. • LID principles and LID BMPs. • Stormwater treatment and flow control BMPs/facilities (c) Permittees shall provide subject area information to the target audience on an ongoing or strategic schedule. Behavior change. To affect behavior change, Permittees shall select, at a minimum, one target audience and one BMP. (a) Target Audiences: Residents, landscapers, property managers/owners, developers, school age children, or businesses (including home-based or mobile businesses). BMPs: • Use and storage of: pesticides, fertilizers, and/or other household chemicals. • Use and storage of: automotive chemicals, hazardous cleaning supplies, carwash soaps, and/or other hazardous materials. • Prevention of illicit discharges. • Yard care techniques protective of water quality. • Carpet cleaning. • Repair and maintenance BMPs for: vehicles, equipment, and/or home/buildings. • Pet waste management and disposal. • LID Principles and LID BMPs. • Stormwater facility maintenance, including LID facilities. • Dumpster and trash compactor maintenance. • Litter and debris prevention. • Sediment and erosion control. • (Audience specific) Source control BMPs (refer to S5.C.8). • (Audience specific) Locally -important, municipal stormwater-related subject area. (b) No later than July 1, 2020, each Permittee shall conduct a new evaluation of the effectiveness of an ongoing behavior change campaign (required under S5.C.1.a.ii and S5.C.1.c of the 2013 Permit). Permittees shall document lessons learned and recommendations for which option to select from S5.C.2.a.ii.(c). Permittees that select option S5.C.2.a.ii.(c)3, below, may forgo this evaluation if it will not add value to the overall behavior change program. Western Washington Phase 11 Municipal Page 15 of 56 Stormwater Permit -August 1, 2019 5.C3 S5.C.3 (c) Based on the recommendation from S5.C.2.am.(b), by February 1, 20211 each Permittee shall follow social marketing practices and methods, similar to community-based social marketing, and develop a campaign that is tailored to the community, including development of a program evaluation plan. Each Permittee shall:' 1. Develop a strategy and schedule to more effectively implement the existing campaign; or 2. Develop a strategy and schedule to expand the existing campaign to a new target audience or BMPs; or 3. Develop a strategy and schedule for a new target audience and BMP behavior change campaign. (d) No later than April 1, 2021, begin to implement the strategy developed in S5.C.2.aJi. (c).6 (e) No later than March 31, 2024, evaluate and report on: 1. The changes in understanding and adoption of targeted behaviors resulting from the implementation of the strategy; and 2. Any planned or recommended changes to the campaign in order to be more effective; describe the strategies and process to achieve the results. (f) Permittees shall use results of the evaluation to continue to direct effective methods and implementation of the ongoing behavior change program. Stewardship. Each Permittee shall provide and advertise stewardship opportunities and/or partner with existing organizations (including non - permittees) to encourage residents to participate in activities or events planned and organized within the community, such as: stream teams, storm drain marking, volunteer monitoring, riparian plantings, and education activities. 3. Public Involvement and Participation Permittees shall provide ongoing opportunities for public involvement and participation through advisory councils, public hearings, watershed committees, participation in developing rate -structures or other similar activities. Each Permittee shall comply with applicable state and local public notice requirements when developing elements of the SWMP and SMAP. The minimum performance measures are: a. Permittees shall create opportunities for the public, including overburdened communities, to participate in the decision-making processes involving the development, implementation and update of the Permittee's SMAP and SWMP.' s No later than August 1, 2021, new Permittees shall follow social marketing practices and methods, similar to Community - Based Social Marketing, to develop a behavior change program that is tailored to the community. 6 No later than October 1, 2021, New Permittees shall begin to implement the strategy developed in S5.C.2.a.ii jc). ' New Permittees shall develop and begin to implement requirements according to S5.C.3.a no later than August 1, 2020. New Permittees are exempt from SMAP this permit term. Western Washington Phase I/ Municipal Page 16 of 56 Stormwater Permit -August 1, 2019 SS.C.4 SS.C.4 b. Each Permittee shall post on their website their SWMP Plan and the annual report, required under S9.A, no later than May 31 each year. All other submittals shall be available to the public upon request. To comply with the posting requirement, a Permittee that does not maintain a website may submit the updated SWMP in electronic format to Ecology for posting on Ecology's website. 4. MS4 Mapping and Documentation The SWMP shall include an ongoing program for mapping and documenting the MS4.' The minimum performance measures are: a. Ongoing Mapping: Each Permittee shall maintain mapping data for the features listed below: Known MS4 outfalls and known MS4 discharge points. ii. Receiving waters, other than groundwater. iii. Stormwater treatment and flow control BMPs/facilities owned or operated by the Permittee. iv. Geographic areas served by the Permittee's MS4 that do not discharge stormwater to surface waters. v. Tributary conveyances to all known outfalls and discharge points with a 24 inch nominal diameter or larger, or an equivalent cross-sectional area for non -pipe systems. The following features or attributes (or both) shall be mapped: (a) Tributary conveyance type, material, and size where known. (b) Associated drainage areas. (c) Land use. Connections between the MS4 owned or operated by the Permittee and other municipalities or public entities. viL All connections to the MS4 authorized or allowed by the Permittee after February 16, 2007. "' b. New Mapping: Each Permittee shall: No later than January 1, 2020, begin to collect size and material for all known MS4 outfalls during normal course of business (e.g. during field screening, inspection, or maintenance) and update records. II. No later than August 1, 2023, complete mapping of all known connections from the MS4 to a privately owned stormwater system. e New Permittees shall meet the requirements to map the MS4 according to S5.C.4. no later than February 2, 2024, except where otherwise noted in this Section. e New Permittees shall meet the requirements of S5.C.4.a.vii after August 1, 2019, for all connections to the MS4 authorized after August 1, 2019. io Permittees do not need to map the following residential connections: individual driveways, sump pumps, or roof downspouts. Western Washington Phase 11 Municipal Page 17 of 56 Stormwater Permit -August 1, 2019 S5.C.S SS.C.S c. No later than August 1, 2021, the required format for mapping is electronic (e.g. Geographic Information System, CAD drawings, or other software that can map and store points, lines, polygons, and associated attributes), with fully described mapping standards. d. To the extent consistent with national security laws and directives, each Permittee shall make available to Ecology, upon request, available maps depicting the information required in S5.C.4.a through c, above. e. Upon request, and to the extent appropriate, Permittees shall provide mapping information to federally recognized Indian Tribes, municipalities, and other Permittees. This Permit does not preclude Permittees from recovering reasonable costs associated with fulfilling mapping information requests by federally recognized Indian Tribes, municipalities, and other Permittees. 5. Illicit Discharge Detection and Elimination The SWIVIP shall include an ongoing program designed to prevent, detect, characterize, trace, and eliminate illicit connections and illicit discharges into the MS4." The minimum performance measures are: a. The program shall include procedures for reporting and correcting or removing illicit connections, spills and other illicit discharges when they are suspected or identified. The program shall also include procedures for addressing pollutants entering the MS4 from an interconnected, adjoining MS4. Illicit connections and illicit discharges must be identified through, but not limited to: field screening, inspections, complaints/reports, construction inspections, maintenance inspections, source control inspections, and/or monitoring information, as appropriate. b. Permittees shall inform public employees, businesses, and the general public of hazards associated with illicit discharges and improper disposal of waste. c. Each Permittee shall implement an ordinance or other regulatory mechanism to effectively prohibit non-stormwater, illicit discharges into the Permittee's MS4 to the maximum extent allowable under state and federal law. Allowable Discharges: The regulatory mechanism does not need to prohibit the following categories ofnon-stormwater discharges: (a) Diverted stream flows (b) Rising groundwatCIS (c) Uncontaminated groundwater infiltration (as defined at 40 CFR 35.2005(b)(20)) (d) Uncontaminated pumped groundwater (e) Foundation drains 11 New Permittees shall meet the requirements of S5.C.5 no later than August 1, 2021 except where otherwise noted in this Section. Western Washington Phase 11 Municipal Page 18 of 56 stormwater Permit- August 1, 2019 56C.5 S5.C.5 (f) Air conditioning condensation (g) Irrigation water from agricultural sources that is commingled with urban stormwater (h) Springs (i) Uncontaminated water from crawl space pumps (j) Footing drains (k) Flows from riparian habitats and wetlands (I) Non-stormwater discharges authorized by another NPDES or state waste discharge permit (m) Discharges from emergency firefighting activities in accordance with S2 Authorized Discharges ii. Conditionally Allowable Discharges: The regulatory mechanism may allow the following categories of non-stormwater discharges only if the stated conditions are met: (a) Discharges from potable water sources, including but not limited to water line flushing, hyperchlorinated water line flushing, fire hydrant system flushing, and pipeline hydrostatic test water. Planned discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH -adjusted, if necessary, and volumetrically and velocity controlled to prevent re -suspension of sediments in the MS4. (b) Discharges from lawn watering and other irrigation runoff. These discharges shall be minimized through, at a minimum, public education activities and water conservation efforts. (c) Dechlorinated swimming pool, spa and hot tub discharges. The discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH -adjusted and reoxygenized if necessary, volumetrically and velocity controlled to prevent re -suspension of sediments in the MS4. Discharges shall be thermally controlled to prevent an increase in temperature of the receiving water. Swimming pool cleaning wastewater and filter backwash shall not be discharged to the MS4. (d) Street and sidewalk wash water, water used to control dust, and routine external building washdown that does not use detergents. The Permittee shall reduce these discharges through, at a minimum, public education activities and/or water conservation efforts. To avoid washing pollutants into the MS4, Permittees shall minimize the amount of street wash and dust control water used. (e) Other non-stormwater discharges. The discharges shall be in compliance with the requirements of a pollution prevention plan reviewed by the Permittee, which addresses control of such discharges. The Permittee shall further address any category of discharges in (i) or (ii), above, if the discharges are identified as significant sources of pollutants to waters of the State. Western Washington Phase II Municipal Page 19 of 56 Storrnwater Permit -August 1, 2019 S5.C.5 S5.C.5 iv. The ordinance or other regulatory mechanism shall include escalating enforcement procedures and actions. d. Each Permittee shall implement an ongoing program designed to detect and identify non-stormwater discharges and illicit connections into the Permittee's MS4,12 The program shall include the following components: Procedures for conducting investigations of the Permittee's MS4, including field screening and methods for identifying potential sources. These procedures may also include source control inspections. The Permittee shall implement a field screening methodology appropriate to the characteristics of the MS4 and water quality concerns. Screening for illicit connections may be conducted using Illicit Connection and Illicit Discharge Field Screening and Source Tracing Guidance Manual (Herrera Environmental Consultants, Inc.; May 2013), or another methodology of comparable or improved effectiveness. The Permittee shall document the field screening methodology in the Annual Report. (a) All Permittees shall complete field screening for an average of 120/. of the MS4 each year. 13 Permittees shall annually track total percentage of the MS4 screened beginning August 1, 2019. publicly listed and publicized hotline or other telephone number for public reporting of spills and other illicit discharges. An ongoing training program for all municipal field staff, who, as part of their normal job responsibilities, might come into contact with or otherwise observe an illicit discharge and/or illicit connection to the MS4, on the identification of an illicit discharge and/or connection, and on the proper procedures for reporting and responding to the illicit discharge and/or connection. Follow-up training shall be provided as needed to address changes in procedures, techniques, requirements, or staffing. Permittees shall document and maintain records of the trainings provided and the staff trained.14 e. Each Permittee shall implement an ongoing program designed to address illicit dischargesI including spills and illicit connections, into the Permittee's MS4.15 The program shall include: i. Procedures for characterizing the nature of, and potential public or environmental threat posed by, any illicit discharges found by or reported to the Permittee. Procedures shall address the evaluation of whether the discharge must be immediately contained and steps to be taken for containment of the discharge. 1z New Permittees shall fully implement the requirements of S5.C.5.d no later than August 1, 2023. 13 New Permittees shall complete S5.C.5.d.i requirements for field screening covering at least 12% of the MS4 within the Permittee's coverage area no later than December 31, 2023, and on average 12% each year thereafter. 14 New Permittees shall develop and begin implementing the ongoing training program described in S5.C.5.d.iii no later than February 2, 2021. is New Permittees shall fully develop and implement the requirements of S5.C.5.e no later than August 1, 2023. Western Washington Phase /I Municipal Page 20 of 56 stormwater Permit -August 1, 2019 S5.C.5 S5.C.5 ii. Procedures for tracing the source of an illicit discharge; including visual inspections, and when necessary, opening manholes, using mobile cameras, collecting and analyzing water samples, and/or other detailed inspection procedures. iii. Procedures for eliminating the discharge, including notification of appropriate authorities (including owners or operators of interconnected MS4s); notification of the property owner; technical assistance; follow-up inspections; and use of the compliance strategy developed pursuant to S5.C.5.c.iv, including escalating enforcement and legal actions if the discharge is not eliminated. iv. Compliance with the provisions in (i), (ii), and (iii), above, shall be achieved by meeting the following timelines: (a) Immediately respond to all illicit discharges, including spills, which are determined to constitute a threat to human health, welfare, or the environment, consistent with General Condition G3. (b) Investigate (or refer to the appropriate agency with the authority to act) within 7 days, on average, any complaints, reports, or monitoring information that indicates a potential illicit discharge. (c) Initiate an investigation within 21 days of any report or discovery of a suspected illicit connection to determine the source of the connection, the nature and volume of discharge through the connection, and the party responsible for the connection. (d) Upon confirmation of an illicit connection, use the compliance strategy in a documented effort to eliminate the illicit connection within 6 months. All known illicit connections to the MS4 shall be eliminated. f. Permittees shall train staff who are responsible for identification, investigation, termination, cleanup, and reporting of cit discharges, including spills, and illicit connections, to conduct these activities. Follow-up training shall be provided as needed to address changes in procedures, techniques, requirements or staffing. Permittees shall document and maintain records of the training provided and the staff trained.1e g. Record keeping: Each Permittee shall track and maintain records of the activities conducted to meet the requirements of this Section. In the Annual Report, each Permittee shall submit data for the illicit discharges, spills and illicit connections including those that were found by, reported to, or investigated by the Permittee during the previous calendar year. The data shall include the information specified in Appendix 12 and WQWebIDDE. Each Permittee may either use their own system or WQWebIDDE for recording this data. Final submittals shall follow the instructions, timelines, and format as described in Appendix 12. 16 New Permittees shall meet the requirements of S5.C.5.f no later than February 2, 2021. Western Washington Phase //Municipal Page 21 of 56 Stormwater Permit -August 1, 2019 SS.C.6 SS.C.6 6. Controlling Runoff from New Development, Redevelopment, and Construction Sites Each Permittee shall implement and enforce a program to reduce pollutants in stormwater runoff to a regulated small MS4 from new development, redevelopment and construction site activities. The program shall apply to private and public development, including transportation projects." The minimum performance measures are: a. Implement an ordinance or other enforceable mechanism that addresses runoff from new development, redevelopment, and construction site projects. Each Permittee shall adopt and make effective a local program, no later than June 30, 2022, that meets the requirements of S5.C.6.b(i) through (iii), below, and shall apply to all applications"$ submitted: i. On or after July 1, 2022. ii. Prior to January 1, 2017, that have not started construction19 by January 1, 2022.20 iii. Prior to July 1, 2022, that have not started construction by July 1, 2027. b. The ordinance or other enforceable mechanism shall include, at a minimum: The Minimum Requirements, thresholds, and definitions in Appendix 1, or the 2013 Appendix 1 amended to include the changes identified in Appendix 10, or Phase I program approved by Ecology and amended to include Appendix 10, for new development, redevelopment, and construction sites. Adjustment and variance criteria equivalent to those in Appendix 1 shall be included. More stringent requirements may be used, and/or certain requirements may be tailored to local circumstances through the use of Ecology -approved basin plans or other similar water quality and quantity planning efforts. Such local requirements and thresholds shall provide equal protection of receiving waters and equal levels of pollutant control to those provided in Appendix 1. The local requirements shall include the following requirements, limitations, and criteria that, when used to implement the minimum requirements in Appendix 1 (or program approved by Ecology under the 2019 Phase I Permit) will protect "For continuing Permittees, this means continuing to implement existing programs developed under previous permits until updates are made to meet the schedules defined. New Permittees shall meet the requirements of S5.C.6 no later than December 31, 2022, except where otherwise specified in this Section. "e In this context, "application" means, at a minimum a complete project description, site plan, and, if applicable, SEPA checklist. Permittees may establish additional elements of a completed application. 19 In this context "started construction" means the site work associated with, and directly related to the approved project has begun. For example: grading the project site to final grade or utility installation. Simply clearing the project site does not constitute the start of construction. Permittees may establish additional requirements related to the start of construction. 20 For Permittees in Lewis and Cowlitz counties: Prior to July 1, 2017, that have not started construction by June 30, 2022. For Lynden, Snoqualmie: Prior to January 1, 2018, that have not started construction by January 1, 2023. For Aberdeen: Prior to July 1, 2018, that have not started construction by June 30, 2023. Shelton and Cla011 County shall adopt and make effective a local program that meets the requirements of S5.C.6.b(i) through (iii) no later than December 31, 2022. The local program shall apply to all applications submitted on or after January 1, 2023, and shall apply to applications submitted prior to January 1, 2023, which have not started construction by January 1, 2028. Western Washington Phase 1 1 Municipal Page 22 of 56 Stormwater Permit- August 1, 2019 5.C.6 S5.C.6 water quality, reduce the discharge of pollutants to the MEP, and satisfy the State requirement under Chapter 90.48 RCW to apply AKART prior to discharge: (a) Site planning requirements (b) BMP selection criteria (c) BMP design criteria (d) BMP infeasibility criteria (e) LID competing needs criteria (f) BMP limitations Permittees shall document how the criteria and requirements will protect water quality, reduce the discharge of pollutants to the MEP, and satisfy State AKART requirements. Permittees who choose to use the requirements, limitations, and criteria, above, in the Stormwater Management Manual for Western Washington, or a Phase I program approved by Ecology, may cite this choice as their sole documentation to meet this requirement. The legal authority, through the approval process for new development and redevelopment, to inspect and enforce maintenance standards for private stormwater facilities approved under the provisions of this Section that discharge to the Permittee's MS4. c. The program shall include a permitting process with site plan review, inspection and enforcement capability to meet the standards listed in (i) through (iv) below, for both private and public projects, using qualified personnel (as defined in Definitions and Acronyms). At a minimum, this program shall be applied to all sites that meet the minimum thresholds adopted pursuant to S5.C.6.b.i, above. i. Review of all stormwater site plans for proposed development activities. ii. Inspect, prior to clearing and construction, all permitted development sites that have a high potential for sediment transport as determined through plan review based on definitions and requirements in Appendix 7 — Determining Construction Site Sediment Damage Potential. As an alternative to evaluating each site according to Appendix 7, Permittees may choose to inspect all construction sites that meet the minimum thresholds adopted pursuant to S5.C.6.b.i, above. Inspect all permitted development sites during construction to verify proper installation and maintenance of required erosion and sediment controls. Enforce as necessary based on the inspection. iv. Each Permittee shall manage maintenance activities to inspect all stormwater treatment and flow control BMPs/facilities, and catch basins, in new residential developments every six months, until 90% of the lots are constructed (or when construction has stopped and the site is fully stabilized), to identify maintenance needs and enforce compliance with maintenance standards as needed. v. Inspect all permitted development sites upon completion of construction and prior to final approval or occupancy to ensure proper installation of permanent Western Washington Phase !l Municipal Page 23 of 56 stormwater Permit -August 1, 2019 5.C17 S5.C,7 stormwater facilities. verify that a maintenance plan is completed and responsibility for maintenance is assigned for stormwater treatment and flow control BMPs/facilities. Enforce as necessary based on the inspection. vi. Compliance with the inspection requirements in (ii) through (v), above, shall be determined by the presence and records of an established inspection program designed to inspect all sites. Compliance during this permit term shall be determined by achieving at least 80% of required inspections. The inspections may be combined with other inspections provided they are performed using qualified personnel. vii. The program shall include a procedure for keeping records of inspections and enforcement actions by staff, including inspection reports, warning letters, notices of violations, and other enforcement records. Records of maintenance inspections and maintenance activities shall be maintained. viii. An enforcement strategy shall be implemented to respond to issues of non- compliance. d. The program shall make available, as applicable, the link to the electronic Construction Stormwater General Permit Notice of Intent (NOI) form for construction activity and, as applicable, a link to the electronic Industrial Stormwater General Permit NOI form for industrial activity to representatives of proposed new development and redevelopment. Permittees shall continue to enforce local ordinances controlling runoff from sites that are also covered by stormwater permits issued by Ecology." e. Each Permittee shall ensure that all staff whose primary job duties are implementing the program to control stormwater runoff from new development, redevelopment, and construction sites, including permitting, plan review, construction site inspections, and enforcement, are trained to conduct these activities. Follow-up training must be provided as needed to address changes in procedures, techniques or staffing. Permittees shall document and maintain records of the training provided and the staff trained .22 7. Operations and Maintenance Each Permittee shall implement and document a program to regulate maintenance activities and to conduct maintenance activities by the Permittee to prevent or reduce stormwater impacts.23 The minimum performance measures are: a. Each Permittee shall implement maintenance standards that are as protective, or more protective, of facility function than those specified in the Stormwater Management Manual for Western Washington or a Phase I program approved by Ecology. For facilities which do not have maintenance standards, the Permittee shall 21 New Permittees shall meet the requirements of S5.C.6.d beginning no later than August 1, 2019. zz New Permittees shall meet the requirements of S5.C.6.e no later than December 31, 2022. z3 New Permittees shall develop and implement the requirements of S5.C.7 no later than December 31, 2022 except where otherwise noted in this Section. Western Washington Phase I! Municipal Page 24 of 56 Stormwater Permit -August 1, 2019 S5.C.7 S5.C.7 develop a maintenance standard. No later than June 30, 2022, Permittees shall update their maintenance standards as necessary to meet the requirements of this Section. i. The purpose of the maintenance standard is to determine if maintenance is required. The maintenance standard is not a measure of the facility's required condition at all times between inspections. Exceeding the maintenance standard between inspections and/or maintenance is not a permit violation. ii. Unless there are circumstances beyond the Permittee's control, when an inspection identifies an exceedance of the maintenance standard, maintenance shall be performed: • Within 1 year for typical maintenance of facilities, except catch basins. • Within 6 months for catch basins. • Within 2 years for maintenance that requires capital construction of less than $25,000. Circumstances beyond the Permittee's control include denial or delay of access by property owners, denial or delay of necessary permit approvals, and unexpected reallocations of maintenance staff to perform emergency work. For each exceedance of the required timeframe, the Permittee shall document the circumstances and how they were beyond their control. b. Maintenance of stormwater facilities regulated by the Permittee i. The program shall include provisions to verify adequate long-term O&M of stormwater treatment and flow control BMPs/facilities that are permitted and constructed pursuant to S.5.C.6.c and shall be maintained in accordance with S5.C.7.a. The provisions shall include: (a) Implementation of an ordinance or other enforceable mechanism that: • Clearly identifies the party responsible for maintenance in accordance with maintenance standards established under S5.C.7.a. • Requires inspection of facilities in accordance with the requirements in (b), below. • Establishes enforcement procedures. (b) Annual inspections of all stormwater treatment and flow control BMPs/facilities that discharge to the MS4 and were permitted by the Permittee according to S5.C.6.c, including those permitted in accordance with requirements adopted pursuant to the 2007-2019 Ecology municipal stormwater permits, unless there are maintenance records to justify a different frequency. Permittees may reduce the inspection frequency based on maintenance recorA s of double the length of time of the proposed inspection frequency. In the absence of maintenance records, the Permittee may substitute written statements to document a specific less frequent inspection schedule. Written statements shall be based on actual inspection and Western Washington Phase 1l Municipal Page 25 of 56 stormwater Permit -August 1, 2019 S5.C.7 S5.C.7 maintenance experience and shall be certified in accordance with G19 — Certification and Signature. Compliance with the inspection requirements in (b), above, shall be determined by the presence and records of an established inspection program designed to inspect all facilities, and achieving at least 80% of required inspections. iii. The program shall include a procedure for keeping records of inspections and enforcement actions by staff, including inspection reports, warning letters, notices of violations, and other enforcement records. Records of maintenance inspections and maintenance activities shall be maintained. c. Maintenance of stormwater facilities owned or operated by the Permittee. Each Permittee shall implement a program to annually inspect all municipally owned or operated stormwater treatment and flow control BMPs/facilities, and taking appropriate maintenance actions in accordance with the adopted maintenance standards. Permittees may reduce the inspection frequency based on maintenance records of double the length of time of the proposed inspection frequency. In the absence of maintenance records, the Permittee may substitute written statements to document a specific less frequent inspection schedule. Written statements shall be based on actual inspection and maintenance experience and shall be certified in accordance with G19 — Certification and Signature. Each Permittee shall spot check potentially damaged stormwater treatment and flow control BMPs/facilities after major storm events (24 hour storm event with a 10 year or greater recurrence interval). If spot checks indicate widespread damage/maintenance needs, inspect all stormwater treatment and flow control BMPs/facilities that may be affected. Conduct repairs or take appropriate maintenance action in accordance with maintenance standards established above, based on the results of the inspections. Each Permittee shall inspect all catch basins and inlets owned or operated by the Permittee every two years.24 Clean catch basins if the inspection indicates cleaning is needed to comply with maintenance standards established in the Stormwater Management Manual for Western Washington. Decant water shall be disposed of in accordance with Appendix 6 —Street Waste Disposal. The following alternatives to the standard approach of inspecting all catch basins every two years may be applied to all or portions of the system: (a) The catch basin inspection schedule of every two years may be changed as appropriate to meet the maintenance standards based on maintenance records of double the length of time of the proposed inspection frequency. In the absence of maintenance records for catch basins, the Permittee may substitute written statements to document a specific, less frequent inspection schedule. Written statements shall be based on actual inspection 24 New Permittees shall inspect and, if needed, clean all catch basins and inlets owned or operated by the Permittee in accordance with the requirements of S5.C.7.c once during the permit term, to be completed no later than February 2, 2024. Western Washington Phase 1l Municipal Page 26 of 56 stormwater Permit- August 1, 2019 5,C.7 S5.C.7 and maintenance experiences and shall be certified in accordance with G19 — Certification and Signature. (b) Inspections every two years may be conducted on a "circuit basis" whereby 25% of catch basins and inlets within each circuit are inspected to identify maintenance needs. Include an inspection of the catch basin immediately upstream of any MS4 outfall, discharge point, or connections to public or private storm systems, if applicable. Clean all catch basins within a given circuit for which the inspection indicates cleaning is needed to comply with maintenance standards established under S5.C.7.a, above. (c) The Permittee may clean all pipes, ditches, and catch basins and inlets within a circuit once during the permit term. Circuits selected for this alternative must drain to a single point. iv. Compliance with the inspection requirements in S5.C.7.c.i-iii, above, shall be determined by the presence of an established inspection program achieving at least 95% of required inspections. d. Implement practices, policies, and procedures to reduce stormwater impacts associated with runoff from all lands owned or maintained by the Permittee, and road maintenance activities under the functional control of the Permittee. No later than December 31, 2022, document the practices, policies, and procedures. Lands owned or maintained by the Permittee include, but are not limited to: streets, parking lots, roads, highways, buildings, parks, open space, road right-of-ways, maintenance yards, and stormwater treatment and flow control BMPs/facilities. The following activities shall be addressed: i. Pipe cleaning ii. Cleaning of culverts that convey stormwater in ditch systems Ditch maintenance iv. Street cleaning v. Road repair and resurfacing, including pavement grinding vi. Snow and ice control vii. Utility installation viii. Pavement striping maintenance ix. Maintaining roadside areas, including vegetation management X. Dust control xi. Application of fertilizers, pesticides, and herbicides according to the instructions for their use, including reducing nutrients and pesticides using alternatives that minimize environmental impacts xii. Sediment and erosion control xiii. Landscape maintenance and vegetation disposal xiv. Trash and pet waste management Western Washington Phase ❑Municipal Page 27 of 56 stormwater Permit -August 1, 2019 S 5. C.8 V. Building exterior cleaning and maintenance e. Implement an ongoing training program for employees of the Permittee whose primary construction, operations, or maintenance job functions may impact stormwater quality. The training program shall address the importance of protecting water quality, operation and maintenance standards, inspection procedures, relevant SWPPPs, selecting appropriate BM Ps, ways to perform their job activities to prevent or minimize impacts to water quality, and procedures for reporting water quality concerns. Follow-up training shall be provided as needed to address changes in procedures, techniques, requirements, or staffing. Permittees shall document and maintain records of training provided. The staff training records to be kept include dates, activities or course descriptions, and names and positions of staff in attendance. f. Implement a Stormwater Pollution Prevention Plan (SWPPP) for all heavy equipment maintenance or storage yards, and material storage facilities owned or operated by the Permittee in areas subject to this Permit that are not required to have coverage under the Industrial Storm water General Permit or another NPDES permit that authorizes stormwater discharges associated with the activity. As necessary, update SWPPPs no later than December 31, 2022, to include the following information. At a minimum, the SWPPP shall include: A detailed description of the operational and structural BMPs in use at the facility and a schedule for implementation of additional BMPs when needed. BMPs selected must be consistent with the Stormwater Management Manual for Western Washington, or a Phase I program approved by Ecology. The SWPPP must be updated as needed to maintain relevancy with the facility. At minimum, annual inspections of the facility, including visual observations of discharges, to evaluate the effectiveness of the BMPs, identify maintenance needs, and determine if additional or different BMPs are needed. The results of these inspections must be documented in an inspection report or check list. An inventory of the materials and equipment stored on-site, and the activities conducted at the facility which may be exposed to precipitation or runoff and could result in stormwater pollution. iv. A site map showing the facility's stormwater drainage, discharge points, and areas of potential pollutant exposure. v. A plan for preventing and responding to spills at the facility which could result in an illicit discharge. g. Maintain records of the activities conducted to meet the requirements of this Section. 8. Source Control Program for Existing Development a. The Permittee shall implement a program to prevent and reduce pollutants in runoff from areas that discharge to the MS4. The program shall include: i. Application of operational source control BMPs, and if necessary, structural source control BMPs or treatment BMPs/facilities, or both, to pollution generating sources associated with existing land uses and activities. Western Washington Phase /!Municipal Page 28 of 56 Stormwater Permit -August 1, 2019 S5.C.8 ii. Inspections of pollutant generating sources at publicly and privately owned institutional, commercial and industrial sites to enforce implementation of required BMPs to control pollution discharging into the MS4. iii. Application and enforcement of local ordinances at sites, identified pursuant to S5.C.8.b.ii, including sites with discharges authorized by a separate NPDES permit. Permittees that are in compliance with the terms of this Permit will not be held liable by Ecology for water quality standard violations or receiving water impacts caused by industries and other Permittees covered, or which should be covered under an NPDES permit issued by Ecology. iv. Practices to reduce polluted runoff from the application of pesticides, herbicides, and fertilizers from the sites identified in the inventory. b. Minimum performance measures: I. No later than August 1, 2022, Permittees shall adopt and make effective an ordinance(s), or other enforceable documents, requiring the application of source control BMPs for pollutant generating sources associated with existing land uses and activities (see Appendix 8 to identify pollutant generating sources). The requirements of this subsection are met by using the source control BMPs in the SWMMWW, or a Phase I Program approved by Ecology. In cases where the manual(s) lack guidance for a specific source of pollutants, the Permittee shall work with the owner/operator to implement or adapt BMPs based on the best professional judgement of the Permittee. Applicable operational source control BMPs shall be required for all pollutant generating sources. Structural source control BMPs, or treatment BMPs/facilities, or both, shall be required for pollutant generating sources if operational source control BMPs do not prevent illicit discharges or violations of surface water, groundwater, or sediment management standards because of inadequate stormwater controls. Implementation of source control requirements may be done through education and technical assistance programs, provided that formal enforcement authority is available to the Permittee and is used as determined necessary by the Permittee, in accordance with S5.C.8.b.iv, below. No later than August 1, 2022, the Permittees shall establish an inventory that identifies publicly and privately owned institutional, commercial, and industrial sites which have the potential to generate pollutants to the MS4. The inventory shall include: (a) Businesses and/or sites identified based on the presence of activities that are pollutant generating (refer to Appendix 8). (b) Other pollutant generating sources, based on complaint response, such as: home-based businesses and multi -family sites. No later than January 1, 2023, Permittees shall implement an inspection program for sites identified pursuant to S5.C.8.b.ii, above. (a) All identified sites with a business address shall be provided information about activities that may generate pollutants and the source control Western Washington Phase /!Municipal Page 29 of 56 stormwater Permit -August 1, 2019 5.C.8 S5.C.8 requirements applicable to those activities. This information shall be provided by mail, telephone, electronic communications, or in person. This information may be provided all at one time or spread out over the permit term to allow for tailoring and distribution of the information during site inspections. (b) The Permittee shall annually complete the number of inspections equal to 20% of the businesses and/or sites listed in their source control inventory to assess BMP effectiveness and compliance with source control requirements. The Permittee may count follow-up compliance inspections at the same site toward the 20% inspection rate. The Permittee may select which sites to inspect each year and is not required to inspect 100% of sites over a 5 -year period. Sites may be prioritized for inspection based on their land use category, potential for pollution generation, proximity to receiving waters, or to address an identified pollution problem within a specific geographic area or sub -basin. (c) Each Permittee shall inspect 100% of sites identified through credible complaints. (d) Permittees may count inspections conducted based on complaints, or when the property owner denies entry, to the 20% inspection rate. No later than January 1, 2023, each Permittee shall implement a progressive enforcement policy that requires sites to comply with stormwater requirements within a reasonable time period as specified below: (a) If the Permittee determines, through inspections or otherwise, that a site has failed to adequately implement required BMPs, the Permittee shall take appropriate follow-up action(s), which may include phone calls, reminder letters, emails, or follow-up inspections. (b) When a Permittee determines that a site has failed to adequately implement BMPa after a follow-up inspection(s), the Permittee shall take enforcement action as established through authority in its municipal codes or ordinances, or through the judicial system. (c) Each Permittee shall maintain records, including documentation of each site visit, inspection reports, warning letters, notices of violations, and other enforcement records, demonstrating an effort to bring sites into compliance. Each Permittee shall also maintain records of sites that are not inspected because the property owner denies entry. (d) A Permittee may refer non -emergency violations of local ordinances to Ecology, provided, the Permittee also makes a documented effort of progressive enforcement. At a minimum, a Permittee's enforcement effort shall include documentation of inspections and warning letters or notices of violation. v. Permittees shall train staff who are responsible for implementing the source controI program to conduct these activities. The ongoing training program shall cover the legal authority for source control, source control BMPs and their proper application, inspection protocols, lessons learned, typical cases, and enforcement Western Washington Phase I! Municipal Page 30 of 56 Storrnwater Permit -August 1, 2019 S6.A.1 S6.A.5 procedures. Follow-up training shall be provided as needed to address changes in procedures, techniques, requirements, or staff. Permittees shall document and maintain records of the training provided and the staff trained. S6. STORMWATER MANAGEMENT PROGRAM FOR SECONDARY PERMITTEES A. This Section applies to all Secondary Permittees and all New Secondary Permittees, whether coverage under this Permit is obtained individually or as a Co -Permittee with a city, town, county, or another Secondary Permittee. New Secondary Permittees subject to this Permit shall fully meet the requirements of this Section as modified in the footnotes in S6.D below, or as established as a condition of coverage by Ecology. 1. To the extent allowable under state, federal or local law, all components are mandatory for each Secondary Permittee covered under this Permit, whether covered as an individual Permittee or as a Co -Permittee. 2. Each Secondary Permittee shall develop and implement a Stormwater Management Program (SWMP). A SWMP is a set of actions and activities comprising the components listed in S6 and any additional actions necessary to meet the requirements of applicable TMDLs pursuant to S7 — Compliance with Total Maximum Daily Load Requirements. The SWMP shall be designed to reduce the discharge of pollutants from regulated small MS4s to the MEP and protect water quality. 3. Unless an alternate implementation schedule is established by Ecology as a condition of permit coverage, the SWIM shall be developed and implemented in accordance with the schedules contained in this Section and shall be fully developed and implemented no later than four and one-half years from the initial permit coverage date. Secondary Permittees that are already implementing some or all of the required SWMP components shall continue implementation of those components. 4. Secondary Permittees may implement parts of their SWMP in accordance with the schedule for cities, towns, and counties in S5, provided they have signed a memorandum of understanding or other agreement to jointly implement the activity or activities with one or more jurisdictions listed in S1.D.2.a or S1.D.2.b, and submitted a copy of the agreement to Ecology. S. Each Secondary Permittee shall prepare written documentation of the SWMP, called the SWMP Plan. The SWMP Plan shall include a description of program activities for the upcoming calendar year. B. Coordination Secondary Permittees shall coordinate Stormwater-related policies, programs and projects within a watershed and interconnected MS4s. Where relevant and appropriate, the SWMP shall coordinate among departments of the Secondary Permittee to ensure compliance with the terms of this Permit. Western Washington Phase ❑Municipal Page 31 of 56 Stormwater Permit -August 1, 2019 C. Legal Authority S6.D.1 To the extent allowable under state law and federal law, each Secondary Permittee shall be able to demonstrate that they can operate pursuant to legal authority which authorizes or enables the Secondary Permittee to control discharges to and from IVIS4s owned or operated by the Secondary Permittee. This legal authority may be a combination of statutes, ordinances, permits, contracts, orders, interagency agreements, or similar instruments. p. Stormwater Management Program for Secondary Permittees The SWMP for Secondary Permittees shall include the following components: 1. Public Education and Outreach Each Secondary Permittee shall implement the following stormwater education strategies: a. Storm drain inlets owned or operated by the Secondary Permittee that are located in maintenance yards, in parking lots, along sidewalks, and at pedestrian access points shall be clearly labeled with a message similar to "Dump no waste — Drains to waterbody."25 As identified during visual inspection and regular maintenance of storm drain inlets per the requirements of S6.D.3.d and S6.D.6.a.i below, or as otherwise reported to the Secondary Permittee, any inlet having a label that is no longer clearly visible and/or easily readable shall be re -labeled within 90 days. b. Each year beginning no later than three years from the initial date of permit coverage, public ports, colleges, and universities shall distribute educational information to tenants and residents on the impact of stormwater discharges on receiving waters, and steps that can be taken to reduce pollutants in stormwater runoff. Distribution may be by hard copy or electronic means. Appropriate topics may include: How stormwater runoff affects local water bodies. Proper use and application of pesticides and fertilizers. Benefits of using well -adapted vegetation. iv. Alternative equipment washing practices, including cars and trucks that minimize pollutants in Stormwater. v. Benefits of proper vehicle maintenance and alternative transportation choices; proper handling and disposal of vehicle wastes, including the location of hazardous waste collection facilities in the area. vi. Hazards associated with illicit connections and illicit discharges. . Benefits of litter control of pet waste. zs New Secondary Permittees shall label all inlets as described in S6.D.1.a no later than four years from the initial date of permit coverage. Western Washington Phase 11 Municipal Page 32 of 56 Stormwater Perrnit -August 1, 2019 S6.D.3 2. Public Involvement and Participation Each year, no later than May 31, each Secondary Permittee shall: a. Make the annual report available on the PerIII ittee's website. b. Make available on the Permittee's website, the latest updated version of the SWMP Plan. c. A Secondary Permittee that does not maintain a website may submit the updated SWMP Plan and annual report in electronic format to Ecology for posting on Ecology's website. 3. Illicit Discharge Detection and Elimination Each Secondary Permittee shall: a. From the initial date of permit coverage, comply with all relevant ordinances, rules, and regulations of the local jurisdiction(s) in which the Secondary Permittee is located that govern non-stormwater discharges. b. Implement appropriate policies prohibiting illicit discharges, 26 and an enforcement plan to ensure compliance with illicit discharge policies.27 These policies shall address, at a minimum: illicit connections, non-stormwater discharges, including spills of hazardous materials, and improper disposal of pet waste and litter. L Allowable discharges: The policies do not need to prohibit the following categories of non-stormwater discharges: (a) Diverted stream flows (b) Rising groundwaters (c) Uncontaminated groundwater infiltration (as defined at 40 CFR 35.2005(b)(20)) (d) Uncontaminated pumped groundwater (e) Foundation drains. (f) Air conditioning condensation (g) Irrigation water from agricultural sources that is commingled with urban stormwater (h) Springs (i) Uncontaminated water from crawl space pumps (j) Footing drains (k) Flows from riparian habitats and wetlands (I) Discharges from emergency firefighting activities in accordance with S2 —Authorized Discharges (m) Non-stormwater discharges authorized by another NPDES or state waste discharge permit ze New Secondary Permittees shall develop and implement appropriate policies prohibiting illicit discharges, and identify possible enforcement mechanisms as described in S6.D.3.b no later than one year from the initial date of permit coverage. 27 New Secondary Permittees shall develop and implement an enforcement plan as described in S6.D.3.b no later than 18 months from the initial date of permit coverage. Western Washington Phase Il Municipal Page 33 of 56 Stormwater Permit- August 1, 2019 S6.D.3 S6.D.3 ii. Conditionally allowable discharges: The policies may allow the following categories of non-stormwater discharges only if the stated conditions are met and such discharges are allowed by local codes: (a) Discharges from potable water sources, including but not limited to water line flushing, hyperchlorinated water line flushing, (b) Fire hydrant system flushing, and pipeline hydrostatic test water. Planned discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH -adjusted if necessary, and volumetrically and velocity controlled to prevent resuspension of sediments in the MS4. (c) Discharges from lawn watering and other irrigation runoff. These discharges shall be minimized through, at a minimum, public education activities and water conservation efforts conducted by the Secondary Permittee and/or the local jurisdiction. (d) Dechlorinated swimming pool, spa and hot tub discharges. The discharges shall be dechlorinated to a total residual chlorine concentration of 0.1 ppm or less, pH -adjusted and reoxygenated if necessary, and volumetrically and velocity controlled to prevent resuspension of sediments in the MS4. Discharges shall be thermally controlled to prevent an increase in temperature of the receiving water. Swimming pool cleaning wastewater and filter backwash shall not be discharged to the MS4. (e) Street and sidewalk wash water, water used to control dust, and routine external building washdown that does not use detergents. The Secondary Permittee shall reduce these discharges through, at a minimum, public education activities and/or water conservation efforts conducted by the Secondary Permittee and/or the local jurisdiction. To avoid washing pollutants into the MS4, the Secondary Permittee shall minimize the amount of street wash and dust control water used. (f) Other non-stormwater discharges shall be in compliance with the requirements of a pollution prevention plan reviewed by the Permittee which addresses control of such discharges. The Secondary Permittee shall address any category of discharges in (i) or (ii), aboveI if the discharge is identified as a significant source of pollutants to waters of the State. c. Maintain a storm sewer system map showing the locations of all known MS4 outfalls and discharge points, labeling the receiving waters (other than groundwater) and delineating the areas contributing runoff to each outfall and discharge point. Make the map (or completed portions of the map) available on request to Ecology and to the extent appropriate, to other Permittees. The preferred format for mapping is an electronic format with fully described mapping standards. 28 d. Conduct field inspections and visually inspect for illicit discharges at all known MS4 outfalls and discharge points. Visually inspect at least one third (on average) of all known outfalls and discharge points each year beginning no later than two years from ze New Secondary Permittees shall meet the requirements of S6.D.3.c no later than four and one-half years from the initial date of permit coverage. Western Washington Phase 11 Municipal Page 34 of 56 stormwater Permit -August 1, 2019 S&DA S60.5 the initial date of permit coverage. Implement procedures to identify and remove any illicit discharges. Keep records of inspections and follow-up activities. e. Implement a spill response plan that includes coordination with a qualified spill responder .29 f. No later than two years from initial date of permit coverage, provide staff training or coordinate with existing training efforts to educate staff on proper BMPs for preventing illicit discharges, including spills. Train all Secondary Permittee staff who, as part of their normal job responsibilities, have a role in preventing such illicit discharges. 4. Construction Site Stormwater Runoff Control From the initial date of permit coverage, each Secondary Permittee shall: a. Comply with all relevant ordinances, rules, and regulations of the local jurisdictions) in which the Secondary Permittee is located that govern construction phase Stormwater pollution prevention measures. b. Ensure that all construction projects under the functional control of the Secondary Permittee which require a construction stormwater permit obtain coverage under the NPDES Construction Stormwater General Permit or an individual NPDES permit prior to discharging construction related Stormwater. c. Coordinate with the local jurisdiction regarding projects owned or operated by other entities which discharge into the Secondary Permittee's MS4, to assist the local jurisdiction with achieving compliance with all relevant ordinances, rules, and regulations of the local jurisdiction(s). d. Provide training or coordinate with existing training efforts to educate relevant staff in erosion and sediment control BMPs and requirements, or hire trained contractors to perform the work. e. Coordinate as requested with Ecology or the local jurisdiction to provide access for inspection of construction sites or other land disturbances which are under the functional control of the Secondary Permittee during land disturbing activities and/or construction period. 5. Post -Construction Stormwater Management for New Development and Redevelopment From the initial date of permit coverage, each Secondary Permittee shall: a. Comply with all relevant ordinances, rules and regulations of the local jurisdictions) in which the Secondary Permittee is located that govern post -construction Stormwater pollution prevention measures. b. Coordinate with the local jurisdiction regarding projects owned or operated by other entities which discharge into the Secondary Permittee's MS4, to assist the local jurisdiction with achieving compliance with all relevant ordinances, rules and regulations of the local jurisdiction(s). z9 New Secondary Permittees shall develop and implement a spill response plan as described in S6.D.3.e no later than four and one-half years from the initial date of permit coverage. Western Washington Phase I! Municipal Page 35 of 56 Stormwater Permit- August 1, 2019 S6.D.6 S6.D.6 6. Pollution Prevention and Good Housekeeping for Municipal Operations Each Secondary Permittee shall: a. Implement a municipal operation and maintenance (O&M) plan to minimize stormwater pollution from activities conducted by the Secondary Permittee. The 0&M Plan shall include appropriate pollution prevention and good housekeeping procedures for all of the following operations, activities, and/or types of facilities that are present within the Secondary Permittee's boundaries and under the functional control of the Secondary Permittee. 30 Stormwater collection and conveyance systems, including catch basins, Stormwater pipes, open channels, culverts, and stormwater treatment and flow control BMPs/facilities. The O&M Plan shall address, at a minimum: scheduled inspections and maintenance activities, including cleaning and proper disposal of waste removed from the system. Secondary Permittees shall properly maintain Stormwater collection and conveyance systems owned or operated by the Secondary Permittee and annually inspect and maintain all stormwater facilities to ensure facility function. Secondary Permittees shall establish maintenance standards that are as protective or more protective of facility function than those specified in Stormwater Management Manual for Western Washington, Secondary Permittees shall review their maintenance standards to ensure they are consistent with the requirements of this Section. Secondary Permittees shall conduct spot checks of potentially damaged permanent stormwater treatment and flow control BMPs/facilities following major storm events (24-hour storm event with a 10 -year or greater recurrence interval). Roads, highways, and parking lots. The O&M Plan shall address, but is not limited to: deicing, anti -icing, and snow removal practices; snow disposal areas; material (e.g., salt, sand, or other chemical) storage areas; all -season BMPs to reduce road and parking lot debris and other pollutants from entering the MS4. Vehicle fleets. The 0&M Plan shall address, but is not limited to: storage, washing, and maintenance of Secondary Permittee vehicle fleets; and fueling facilities. Secondary Permittees shall conduct all vehicle and equipment washing and maintenance in a self-contained covered building or in designated wash and/or maintenance areas. iv. External building maintenance. The O&M Plan shall address, building exterior cleaning and maintenance including cleaning, washing, painting; and maintenance and management of dumpsters; and other maintenance activities. v. Parks and open space. The O&M Plan shall address, but is not limited to: proper application of fertilizer, pesticides, and herbicides; sediment and erosion control; BMPs for landscape maintenance and vegetation disposal; and trash and pet waste management. ao New Secondary Permittees shall develop and implement the operation and maintenance plan described in S6.D.6.a no later than three years from initial date of permit coverage. Western Washington Phase l/Municipal Page 36 of 56 Stormwater Permit -August 1, 2019 S6.D.6 S6.D.6 vi. Material storage facilities and heavy equipment maintenance or storage yards. Secondary Permittees shall develop and implement a Stormwater Pollution Prevention Plan to protect water quality at each of these facilities owned or operated by the Secondary Permittee and not covered under the Industrial Stormwater General Permit or under another NPDES permit that authorizes stormwater discharges associated with the activity. vii. Other facilities that would reasonably be expected to discharge contaminated runoff. The 0&M Plan shall address proper stormwater pollution prevention practices for each facility. b. From the initial date of permit coverage, Secondary Permittees shall also have permit coverage for all facilities operated by the Secondary Permittee that are required to be covered under the Industrial Storm water General Permit or another NPDES permit that authorizes discharges associated with the activity. c. The 0&M Plan shall include sufficient documentation and records as necessary to demonstrate compliance with the O&M Plan requirements in S6.D.6.a(i) through (vii), above. d. No later than three years from the initial date of permit coverage, Secondary Permittees shall implement a program designed to train all employees whose primary construction, operations, or maintenance job functions may impact stormwater quality. The training shall address: i. The importance of protecting water quality. ii. The requirements of this Permit. iii. Operation and maintenance requirements. iv. Inspection procedures. v. Ways to perform theirjob activities to prevent or minimize impacts to water quality. vi. Procedures for reporting water quality concerns, including potential illicit discharges (including spills). S7. COMPLIANCE WITH TOTAL MAXIMUM DAILY LOAD REQUIREMENTS The following requirements apply if an applicable TMDL is approved for stormwater discharges from MS4s owned or operated by the Permittee. Applicable TMDLs are TMDLs which have been approved by EPA on or before the issuance date of this Permit or prior to the date that Ecology issues coverage under this Permit, whichever is later. A. For applicable TMDLs listed in Appendix 2, affected Permittees shall comply with the specific requirements identified in Appendix 2. Each Permittee shall keep records of all actions required by this Permit that are relevant to applicable TMDLs within their jurisdiction. The status of the TMDL implementation shall be included as part of the annual report submitted to Ecology. Each annual report shall include a summary of relevant SWMP and Appendix 2 activities conducted in the TMDL area to address the applicable TMDL parameter(s). Western Washington Phase 1/ Municipal Page 37 of 56 stormwater Permit -August 1, 2019 S8.A.1 S8.B.1 B. For applicable TMDLs not listed in Appendix 2, compliance with this Permit shall constitute compliance with those TMDLs. C. For TMDLs that are approved by EPA after this Permit is issued, Ecology may establish TMDL related permit requirements through future permit modification if Ecology determines implementation of actions, monitoring, or reporting necessary to demonstrate reasonable further progress toward achieving TMDL waste load allocations, and other targets, are not occurring and shall be implemented during the term of this Permit or when this Permit is reissued. Permittees are encouraged to participate in development of TMDLs within their jurisdiction and to begin implementation. S8. MONITORING AND ASSESSMENT A. Regional Status and Trends Monitoring 1. All Permittees that chose S8.B Status and Trends Monitoring Option #1 in the Phase 11 Western Washington Municipal Storm water Permit, August 1, 2013 —July 31, 2018 (extended to July 31, 2019), shall make a one-time payment into the collective fund to implement regional small streams and marine nearshore areas status and trends monitoring in Puget Sound. This payment is due on or before December 1, 2019. Submit payment according to Section S8.D, below. 2. All City and County Permittees covered under the Phase 11 Western Washington Municipal Stormwater Permit, August 1, 2013 — July 31, 2018 (extended to July 31, 2019), except the Cities of Aberdeen and Centralia, shall notify Ecology in writing which of the following two options for regional status and trends monitoring (S8.A.2.a or S8.A.2.b) the Permittee chooses to carry out during this permit term. The written notification with G19 signature is due to Ecology no later than December 1, 2019. a. Make annual payments into a collective fund to implement regional receiving water status and trends monitoring of either: small streams and marine nearshore areas in Puget Sound; or, urban streams in Clark and Cowlitz Counties in the Lower Columbia River basin, depending on the Permittee's location. The annual payments into the collective fund are due on or before August 15 each year beginning in 2020. Submit payments according to Section S8.D, below. Or b. Conduct stormwater discharge monitoring per the requirements in 58.C. Either option will fully satisfy the Permittee 's obligations under this Section (S8.A.2). Each Permittee shall select a single option for this permit term. B. stormwater Management Program (SWMP) Effectiveness and Source Identification Studies 1. All Permittees that chose 58.0 Effectiveness Studies Option #1 in the Phase 11 Western Washington Municipal stormwater Permit, August 1, 2013 —July 31, 2018 (extended to July 31, 2019), shall make a one-time payment into the collective fund to implement effectiveness studies and source identification studies. The payment is due on or before December 1, 2019. Submit payment according to Section S8.D, below. Western Washington Phase /1 Municipal Page 38 of 56 stormwater Permit -August 1, 2019 S83.2 S8.C,1 2. All City and County Permittees covered under the Phase u Western Washington Municipal Stormwater Permit, August 1, 2013 —July 31, 2018 (extended to July 31, 2019), shall notify Ecology in writing which of the following two options (S8.B.2.a or S8.13.2.b) for effectiveness and source identification studies the Permittee chooses to carry out during this permit term. The written notification with G19 signature is due to Ecology no later than December 1, 2019. a. Make annual payments into a collective fund to implement effectiveness and source identification studies. The annual payments into the collective fund are due on or before August 15 each year beginning in 2020. Submit payments according to Section S8.D, below. Or b. Conduct stormwater discharge monitoring per the requirements in S8.C. Either option will fully satisfy the Permittee's obligations under this Section (S8.6.2). Each Permittee shall select a single option for this permit term. 3. All Permittees shall provide information as requested for effectiveness and source identification studies that are under contract with Ecology as active Stormwater Action Monitoring (SAM) projects. These requests will be limited to records of SWMP activities and associated data tracked and/or maintained in accordance with S5 —Stormwater Management Program for Cities, Towns, and Counties and/or S9 —Reporting Requirements. A maximum of three requests during the permit term from the SAM Coordinator will be transmitted to the Permittee's permit coordinator via Ecology's regional permit manager. The Permittee shall have 90 days to provide the requested information. C. stormwater discharge monitoring. 1. This Section applies only to Permittees who choose to conduct stormwater discharge monitoring per S8.A.2.b and/or S8.B.2.b in lieu of participation in the regional status and trends monitoring and/or effectiveness and source identification studies. These Permittees shall conduct monitoring in accordance with Appendix 9 and an Ecology - approved Quality Assurance Project Plan (QAPP) as follows: a. Permittees who choose the option to conduct stormwater discharge monitoring for either S8.A.2 or S8.B.2 shall monitor three independent discharge locations. Permittees who choose the option to conduct stormwater discharge monitoring for both S8.A.2 and S8.13.2 shall conduct this monitoring at a total of six locations; at least four locations shall be independent (one location may be nested in another basin). b. No later than February 1, 2020, each Permittee shall submit to Ecology a draft stormwater discharge monitoring QAPP for review and approval. The QAPP shall be prepared in accordance with the requirements in Appendix 9. The final QAPP shall be submitted to Ecology for approval as soon as possible following finalization, and before August 15, 2020 or within 60 days of receiving Ecology's comments on the draft QAPP (whichever is later). c. Flow monitoring shall begin no later than October 1, 2020 or within 30 days of receiving Ecology's approval of the final QAPP (whichever is later). Stormwater discharge monitoring shall be fully implemented no later than October 1, 2021, Western Washington Phase /1 Municipal Page 39 of 56 Stormwater Permit -August 1, 2019 S8.D.1 S90.2 d. Data and analyses shall be reported annually in accordance with the Ecology - approved QAPP. Each Permittee shall enter into the Department's Environmental Information Management (EIM) database all water and solids concentration data collected pursuant to Appendix 9. p. Payments into the collective funds. 1. Each Permittee's S8.A and S8.B payment amounts are listed in Appendix 11 and in the invoices that will be sent to the Permittee approximately three months in advance of each payment due date. 2. Mail payments according to the instructions in the invoice, or via United States Postal Service to: Department of Ecology Cashiering Unit P.O. Box 47611 Olympia, WA 98405-7611 S9. REPORTING REQUIREMENTS A. No later than March 31 of each year beginning in 2020, each Permittee shall submit an annual report. The reporting period for the annual report will be the previous calendar year unless otherwise specified. Permittees shall submit annual reports electronically using Ecology's Water Quality Permitting Portal (WQWebPortal) available on Ecology's website. Permittees unable to submit electronically through Ecology's WQWebPortal shall contact Ecology to request a waiver and obtain instructions on how to submit an annual report in an alternative format. 13. Each Permittee is required to keep all records related to this Permit and the SWMP for at least fiVC years. C. Each Permittee shall make all records related to this Permit and the Permittee's SWMP available to the public at reasonable times during business hours. The Permittee will provide a copy of the most recent annual report to any individual or entity, upon request. 1. A reasonable charge may be assessed by the Permittee for making photocopies of records. 2. The Permittee may require reasonable advance notice of intent to review records related to this Permit. D. The annual report for cities, towns, and counties Each annual report shall include the following: 1. A copy of the Permittee's current SWMP Plan, as required by S5.A.2. 2. Submittal of the annual report form as provided by Ecology pursuant to S9.A, describing the status of implementation of the requirements of this Permit during the reporting period. Western Washington Phase ❑Municipal Page 40 of 56 Stormwater Permit -August 1, 2019 9.D.3 S9.E.5 3. Attachments to the annual report form including summaries, descriptions, reports, and other information as required, or as applicable, to meet the requirements of this Permit during the reporting period, or as a required submittal. Refer to Appendix 3 for annual report questions. 31 4. If applicable, notice that the MS4 is relying on another governmental entity to satisfy any of the obligations under this Permit. 5. Certification and signature pursuant to G19.D, and notification of any changes to authorization pursuant to G19.C. 6. A notification of any annexations, incorporations or jurisdictional boundary changes resulting in an increase or decrease in the Permittee's geographic area of permit coverage during the reporting period. E. Annual report for Secondary Permittees Each annual report shall include the following: 1. Submittal of the annual report form as provided by Ecology pursuant to S9.A, describing the status of implementation of the requirements of this Permit during the reporting period. 2. Attachments to the annual report form including summaries, descriptions, reports, and other information as required, or as applicable, to meet the requirements of this Permit during the reporting period. Refer to Appendix 4 for annual report questions. 3. If applicable, notice that the MS4 is relying on another governmental entity to satisfy any of the obligations under this Permit. 4. Certification and signature pursuant to G19.1) , and notification of any changes to authorization pursuant to G19.C. S. A notification of any jurisdictional boundary changes resulting in an increase or decrease in the Secondary Permittee'a geographic area of permit coverage during the reporting period. 31 New Permittees refer to Appendix 5 for annual report questions. Western Washington Phase (I Municipal Page 41 of 56 Stormwater Permit- August 1, 2019 GENERAL CONDITIONS G1. DISCHARGE VIOLATIONS All discharges and activities authorized by this Permit shall be consistent with the terms and conditions of this Permit. G2. PROPER OPERATION AND MAINTENANCE The Permittee shall at all times properly operate and maintain all facilities and systems of collection, treatment, and control (and related appurtenances) which are installed or used by the Permittee for pollution control to achieve compliance with the terms and conditions of this Permit. G3. NOTIFICATION OF DISCHARGE, INCLUDING SPILLS If a Permittee has knowledge of a discharge, including spills, into or from a MS4 which could constitute a threat to human health, welfare, or the environment, the Permittee shall: A. Take appropriate action to correct or minimize the threat to human health, welfare and/or the environment. B. Notify the Ecology regional office and other appropriate spill response authorities immediately but in no case later than within 24 hours of obtaining that knowledge. C. Immediately report spills or other discharges which might cause bacterial contamination of marine waters, such as discharges resulting from broken sewer lines and failing onsite septic systems, to the Ecology regional office and to the Department of Health, Shellfish Program. D. Immediately report spills or discharges of oils or hazardous substances to the Ecology regional office and to the Washington Emergency Management Division at 1-800-258-5990. G4. BYPASS PROHIBITED The intentional bypass of stormwater from all or any portion of a stormwater treatment BMP whenever the design capacity of the treatment BMP is not exceeded, is prohibited unless the following conditions are met: A. Bypass is: (1) unavoidable to prevent loss of life, personal injury, or severe property damage; or (2) necessary to perform construction ormaintenance-related activities essential to meet the requirements of the Clean Water Act (CWA); and B. There are no feasible alternatives to bypass, such as the use of auxiliary treatment facilities, retention of untreated stormwater, or maintenance during normal dry periods. "Severe property damage" means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Western Washington Phase 11 Municipal Page 42 of 60 Storm water Permit G5 G9 G5. RIGHT OF ENTRY The Permittee shall allow an authorized representative of Ecology, upon the presentation of credentials and such other documents as may be required by law at reasonable times: A. To enter upon the Permittee's premises where a discharge is located or where any records shall be kept under the terms and conditions of this Permit. B. To have access to, and copy at reasonable cost and at reasonable times, any records that shall be kept under the terms of the Permit. C. To inspect at reasonable times any monitoring equipment or method of monitoring required in the Permit. D. To inspect at reasonable times any collection, treatment, pollution management, or discharge facilities. E. To sample at reasonable times any discharge of pollutants. G6. DUTY TO MITIGATE The Permittee shall take all reasonable steps to minimize or prevent any discharge in violation of this Permit which has a reasonable likelihood of adversely affecting human health or the environment. G7. PROPERTY RIGHTS This Permit does not convey any property rights of any sort, or any exclusive privilege. G8. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in the Permit shall be construed as excusing the Permittee from compliance with any other applicable federal, state, or local statutes, ordinances, or regulations. G9. MONITORING A. Representative Sampling Samples and measurements taken to meet the requirements of this Permit shall be representative of the volume and nature of the monitored discharge, including representative sampling of any unusual discharge or discharge condition, including bypasses, upsets, and maintenance -related conditions affecting effluent quality. B. Records Retention The Permittee shall retain records of all monitoring information, including all calibration and maintenance records and all original recordings for continuous monitoring instrumentation, copies of all reports required by this Permit, and records of all data used to complete the application for this Permit, for a period of at least five years. This period of retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by the Ecology. On request, monitoring data and analysis shall be provided to Ecology. C. Recording of Results For each measurement or sample taken, the Permittee shall record the following information: (1) the date, exact place and time of sampling; (2) the individual who Western Washington Phase ❑Municipal Page 43 of 56 Storm water Permit -August 1, 2019 G10 G11 performed the sampling or measurement; (3) the dates the analyses were performed; (4) who performed the analyses; (5) the analytical techniques or methods used; and (6) the results of all analyses. D. Test Procedures All sampling and analytical methods used to meet the monitoring requirements in this Permit shall conform to the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 CFR Part 136, unless otherwise specified in this Permit or approved in writing by Ecology. E. Flow Measurement Appropriate flow measurement devices and methods consistent with accepted scientific practices shall be selected and used to ensure the accuracy and reliability of measurements of the volume of monitored discharges. The devices shall be installed, calibrated, and maintained to ensure that the accuracy of the measurements is consistent with the accepted industry standard for that type of device. Frequency of calibration shall be in conformance with manufacturer's recommendations or at a minimum frequency of at least one calibration per year. Calibration records should be maintained for a minimum of three years. F. Lab Accreditation All monitoring data, except for flow, temperature, conductivity, pH, total residual chlorine, and other exceptions approved by Ecology, shall be prepared by a laboratory registered or accredited under the provisions of, Accreditation of Environmental Laboratories, Chapter 173-50 WAC. Soils and hazardous waste data are exempted from this requirement pending accreditation of laboratories for analysis of these media by Ecology. Quick methods of field detection of pollutants including nutrients, surfactants, salinity, and other parameters are exempted from this requirement when the purpose of the sampling is identification and removal of a suspected illicit discharge. G. Additional Monitoring Ecology may establish specific monitoring requirements in addition to those contained in this Permit by administrative order or permit modification. G10. REMOVED SUBSTANCES With the exception of decant from street waste vehicles, the Permittee shall not allow collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of stormwater to be resuspended or reintroduced to the MS4 or to waters of the State. Decant from street waste vehicles resulting from cleaning stormwater facilities may be reintroduced only when other practical means are not available and only in accordance with the Street Waste Disposal Guidelines in Appendix 6. Solids generated from maintenance of the MS4 may be reclaimed, recycled, or reused when allowed by local codes and ordinances. Soils that are identified as contaminated pursuant to Chapter 173-350 WAC shall be disposed at a qualified solid waste disposal facility (see Appendix 6). G11. SEVERABILITY The provisions of this Permit are severable, and if any provision of this Permit, or the application of any provision of this Permit to any circumstance, is held invalid, the application of such provision to other circumstances, and the remainder of this Permit shall not be affected thereby. Western Washington Phase ❑Municipal Page 44 of 56 Stormwater Permit -August 1, 2019 G12 G12. REVOCATION OF COVERAGE G15 The director may terminate coverage under this General Permit in accordance with Chapter 43.2113 RCW and Chapter 173-226 WAC. Cases where coverage may be terminated include, but are not limited to the following: A. Violation of any term or condition of this general permit; B. Obtaining coverage under this general permit by misrepresentation or failure to disclose fully all relevant facts; C. A change in any condition that requires either a temporary or permanent reduction or elimination of the permitted discharge; D. A determination that the permitted activity endangers human health or the environment, or contributes significantly to water quality standards violations; E. Failure or refusal of the Permittee to allow entry as required in Chapter 90.48.090 RCW; F. Nonpayment of permit fees assessed pursuant to Chapter 90.48.465 RCW; Revocation of coverage under this general permit may be initiated by Ecology or requested by any interested person. G13. TRANSFER OF COVERAGE The director may require any discharger authorized by this General Permit to apply for and obtain an individual permit in accordance with Chapter 43.2113 RCW and Chapter 173-226 WAC. G14. GENERAL PERMIT MODIFICATION AND REVOCATION This General Permit may be modified, revoked and reissued, or terminated in accordance with the provisions of WAC 173-226-230. Grounds for modification, revocation Cl"d reissuance, or termination include, but are not limited to the following: A. A change occurs in the technology or practices for control or abatement of pollutants aVVlicable to the category of dischargers covered under this General Permit; B. Effluent limitation guidelines or standards are promulgated pursuant to the CWA or Chapter 90.48 RCW, for the category of dischargers covered under this General Permit; C. A water quality management plan containing requirements applicable to the category of dischargers covered under this General Permit is approved; or D. Information is obtained which indicates that cumulative effects on the environment from dischargers covered under this General Permit are unacceptable. E. Changes instate law that reference this Permit. G15. REPORTING A CAUSE FOR MODIFICATION OR REVOCATION A Permittee who knows or has reason to believe that any activity has occurred or will occur which would constitute cause for modification or revocation and reissuance under General Condition G12, G14, or 40 CFR 122.62 must report such plans, or such information, to Ecology so that a decision can be made on whether action to modify, or revoke and reissue this Permit will be Western Washington Phase I/ Municipal Page 45 of 56 Stormwater Permit- August 1, 2019 G16 G19 required. Ecology may then require submission of a new or amended application. Submission of such application does not relieve the Permittee of the duty to comply with this Permit until it is modified or reissued. G16. APPEALS A. The terms and conditions of this General Permit, as they apply to the appropriate class of dischargers, are subject to appeal within thirty days of issuance of this General Permit, in accordance with Chapter 43.2113 RCW, and Chapter 173-226 WAC. B. The terms and conditions of this General Permit, as they apply to an individual discharger, are appealable in accordance with Chapter 43.2113 RCW within thirty days of the effective date of coverage of that discharger. Consideration of an appeal of General Permit coverage of an individual discharger is limited to the General Permit's applicability or nonapplicability to that individual discharger. C. The appeal of General Permit coverage of an individual discharger does not affect any other dischargers covered under this General Permit. If the terms and conditions of this General Permit are found to be inapplicable to any individual discharger(s), the matter shall be remanded to Ecology for consideration of issuance of an individual permit or permits. D. Modifications of this Permit are appealable in accordance with Chapter 43.216 RCW and Chapter 173-226 WAC. G17. PENALTIES 40 CFR 122.41(a)(2) and (3), 40 CFR 122.41(j)(5), and 40 CFR 122.41(k)(2) are hereby incorporated into this Permit by reference. G18. DUTY TO REAPPLY The Permittee shall apply for permit renewal at least 180 days prior to the specified expiration date of this Permit. G19. Certification and Signature All formal submittals to Ecology shall be signed and certified. A. All permit applications shall be signed by either a principal executive officer or ranking elected official. B. All formal submittals required by this Permit shall be signed by a person described, above, or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by a person described, above, and submitted to Ecology, and 2. The authorization specifies either an individual or a position having responsibility for the overall development and implementation of the stormwater management program. (A duly authorized representative may thus be either a named individual or any individual occupying a named position.) Western Washington Phase !/ Municipal Page 46 of 56 stormwater Permit -August 1, 2019 G20 CeI►�il C. Changes to authorization. If an authorization under condition G19.13.2 is no longer accurate because a different individual or position has responsibility for the overall development and implementation of the stormwater management program, a new authorization satisfying the requirements of condition G19.B.2 must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Cercation. Any person signing a formal submittal under this Permit shall make the following certification: "I certify, under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that Qualified Personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for willful violations." G20. Non-compliance notification In the event a Permittee is unable to comply with any of the terms and conditions of this Permit, the Permittee must: A. Notify Ecology of the failure to comply with the permit terms and conditions in writing within 30 days of becoming aware that the non-compliance has occurred. The written notification must include all of the following: 1. A description of the non-compliance, including dates. 2. Beginning and end dates of the non-compliance, and if the compliance has not been corrected, the anticipated date of correction. 3. Steps taken or planned to reduce, eliminate, or prevent reoccurrence of the non- compliance. B. Take appropriate action to stop or correct the condition of non-compliance. G21. UPSETS Permittees must meet the conditions of 40 CFR 122.41(n) regarding "Upsets." The conditions are as follows: A. Definition. "Upset" means an exceptional incident in which there is unintentional and temporary noncompliance with technology based permit effluent limitations because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. B. Effect of an upset. An upset constitutes an affirmative defense to an action brought for noncompliance with such technology based permit effluent limitations if the requirements of paragraph (C) of this condition are met. Any determination made during administrative Western Washington Phase 11 Municipal Page 47 of 56 Stormwater Permit -August 1, 2019 G21 review of claims that noncompliance was caused by upset, and before an action for noncompliance, will not constitute final administrative action subject to judicial review. G21 C. Conditions necessary for demonstration of upset. A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed contemporaneous operating logs, or other relevant evidence that: 1. An upset occurred and that the Permittee can identify the causes) of the upset; 2. The permitted facility was at the time being properly operated; and 3. The Permittee submitted notice of the upset as required in 40 CFR 122.41(I)(6)(ii)(B) (24- hour notice of noncompliance). 4. The Permittee complied with any remedial measures required under 40 CFR 122.41(d) (Duty to Mitigate). D. Burden of proof. In any enforcement proceeding, the Permittee seeking to establish the occurrence of an upset has the burden of proof. Western Washington Phase !/ Municipal Page 48 of 56 Stormwater Permit -August 1, 2019 DEFINITIONS AND ACRONYMS This Section includes definons for terms used in Y of the Permit and in all the appendices except Appendix 1. Terms defined in Appendix 1 are necessary to implement requirements related to Appendix 1. 40 CFR means Title 40 of the Code of Federal Regulations, which is the codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the federal government. AKART means All Known, Available, and Reasonable methods of prevention, control and Treatment. See aIso State Water Pollution Control Act, Chapter 90.48.010 RCW and Chapter 90.48.520 RCW. All Known, Available and Reasonable Methods of Prevention, Control and Treatment (AKART) refers to the State Water Pollution Control Act, Chapter 90.48.010 RCW and Chapter 90.48.520 RCW. Applicable TMDL means a TMDL which has been approved by EPA on or before the issuance date of this Permit, or prior to the date that Ecology issues coverage under this Permit, whichever is later. Beneficial Uses means uses of waters of the State, which include but are not limited to use for domestic, stock watering, industrial, commercial, agricultural, irrigation, mining, fish and wildlife maintenance and enhancement, recreation, generation of electric power and preservation of environmental and aesthetic values, and all other uses compatible with the enjoyment of the public waters of the State. Best Management Practices are the schedules of activities, prohibitions of practices, maintenance procedures, and structural and/or managerial practices approved by Ecology that, when used singly or in combination, prevent or reduce the release of pollutants and other adverse impacts to waters of Washington State. BMP means Best Management Practice. Bypass means the diversion of stormwater from any portion of a stormwater treatment facility. Circuit means a portion of a MS4 discharging to a single point or serving a discrete area determined by traffic volumes, land use, topography or the configuration of the MS4. Component or Program Component means an element of the stormwater Management Program listed in S5 -stormwater Management Program for Cities, Towns, and Counties, or S6 —stormwater Management Program for Secondary Permittees, or S7 — Compliance with Total Maximum Daily Load Requirements, or S8 — Monitoring and Assessment, of this Permit. Community-based social marketing is a social marketing methodology. It employs a systematic approach intended to change the behavior of communities to reduce their impact on the environment. Realizing that providing information is usually not sufficient to initiate behavior change, community- based social marketing uses tools and findings from social psychology to discover the perceived barriers to behavior change and ways of overcoming these barriers. Conveyance System means that portion of the municipal separate storm sewer system designed or used for conveying stormwater. Western Washington Phase /I Municipal Page 49 of 56 stormwater Permit -August 1, 2019 Co -Permittee means an owner or operator of an MS4 which is in a cooperative agreement with at least one other applicant for coverage under this Permit. A Co -Permittee is an owner or operator of a regulated MS4 located within or in proximity to another regulated MS4. A Co -Permittee is only responsible for permit conditions relating to discharges from the MS4 the Co -Permittee owns or operates. See also 40 CFR 122.26(b)(1). CWA means Clean Water Act (formerly referred to as the Federal Water Pollution Control Actor Federal Water Pollution Control Act Amendments of 1972) Pub.L. 92-500, as amended Pub. L. 95-217, Pub. L. 95- 576, Pub. L. (6-483 and Pub. L. 974171 33 U.S.C. 1251 etseq.). Director means the Director of the Washington State Department of Ecology, or an authorized representative. Discharge Point means the location where a discharge leaves the Permittee's MS4 through the Permittee's MS4 facilities/BMPs designed to infiltrate. Entity means a governmental body, or a public or private organization. EPA means the U.S. Environmental Protection Agency. Fully Stabilized means the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as riprap, gabions or geotextiles) which prevents erosion. General Permit means a permit which covers multiple dischargers of a point source category within a designated geographical area, in lieu of individual permits being issued to each discharger. Groundwater means water in a saturated zone or stratum beneath the surface of the land or below a surrace water body. Refer to Chapter 173-200 WAC. Hazardous Substance means any liquid, solid, gas, or sludge, including any material, substance, product, commodity, or waste, regardless of quantity, that exhibits any of the physical, chemical, or biological properties described in WAC 173-303-090 or WAC 173-303400. Heavy Equipment Maintenance or Storage Yard means an uncovered area where any heavy equipment, such as mowing equipment, excavators, dump trucks, backhoes, or bulldozers are washed or maintained, or where at least five pieces of heavy equipment are stored on a long-term basis. Highway means a main public road connecting towns and cities. Hydraulically Near means runoff from the site discharges to the sensitive feature without significant natural attenuation of flows that allows for suspended solids removal. See Appendix 7 Determining Construction Site Sediment Damage Potential for a more detailed definition. Hyperchlorinated means water that contains more than 10 mg/Liter chlorine. Illicit Connection means any infrastructure connection to the MS4 that is not intended, permitted or used for collecting and conveying stormwater ornon-stormwater discharges allowed as specified in this Permit (S5.C.5 and S6.D.3). Examples include sanitary sewer connections, floor drains, channels, pipelines, conduits, inlets, or outlets that are connected directly to the MS4. Illicit Discharge means any discharge to a MS4 that is not composed entirely of stormwater or of non- stormwaterdischarges allowed as specified in this Permit (S5.C.5 and S6.D.3). Western Washington Phase !/ Municipal Page 50 of 56 stormwater Permit -August 1, 2019 Impervious Surface means a non -vegetated surface area that either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A non -vegetated surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or stormwater areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Land Disturbing Activity means any activity that results in a change in the existing soil cover (both vegetative and non -vegetative) and/or the existing soil topography. Land disturbing activities include, but are not limited to clearing, grading, filling and excavation. Compaction that is associated with stabilization of structures and road construction shall also be considered land disturbing activity. Vegetation maintenance practices, including landscape maintenance and gardening, are not considered land disturbing activity. Stormwater facility maintenance is not considered land disturbing activity if conducted according to established standards and procedures. LID means Low Impact Development. LID BMP means Low Impact Development Best Management Practices. LID Principles means land use management strategies that emphasize conservation, use of on-site natural features, and site planning to minimize impervious surfaces, native vegetation loss, and stormwater runoff. Low Impact Development (LID) means a stormwater and land use management strategy that strives to mimic pre -disturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design. Low Impact Development Best Management Practices (LID BMP) means distributed stormwater management practices, integrated into a project design, that emphasize pre -disturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration. LID BMPs include, but are not limited to, bioretention, rain gardens, permeable pavements, roof downspout controls, dispersion, soil quality and depth, vegetated roofs, minimum excavation foundations, and water re -use. Material Storage Facilities means an uncovered area where bulk materials (liquid, solid, granular, etc.) are stored in piles, barrels, tanks, bins, crates, or other means. Maximum Extent Practicable refers to paragraph 402(p)(3)(13 )(iii) of the federal Clean Water Act which reads as follows: Permits for discharges from municipal storm sewers shall require controls to reduce the discharge of pollutants to the maximum extent practicable, including management practices, control techniques, and system, design, and engineering methods, and other such provisions as the Administrator or the State determines appropriate for the control of such pollutants. MEP means Maximum Extent Practicable. MSLI means Municipal Separate Storm Sewer System. Municipal Separate Storm Sewer System means a conveyance, or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains): Western Washington Phase I! Municipal Page 51 Fr stormwater Permit -August 1, 2019 (i) Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of wastes, stormwater, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under Section 208 of the CWA that discharges to waters of Washington State. (ii) Designed or used for collecting or conveying stormwater. (iii) Which is not a combined sewer; (iv) Which is not part of a Publicly Owned Treatment Works (POTW) as defined at 40 CFR 122.2.; and (v) Which is defined as "large" or "medium" or "small' or otherwise designated by Ecology pursuant to 40 CFR 122.26. National Pollutant Discharge Elimination System means the national program for issuing, modifying, revoking, and reissuing, terminating, monitoring and enforcing permits, and imposing and enforcing pretreatment requirements, under Sections 307, 402, 318, and 405 of the Federal Clean Water Act, for the discharge of pollutants to surface waters of the State from point sources. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington State Department A Ecology. Native Vegetation means vegetation comprised of plant species, other than noxious weeds, that are indigenous to the coastal region of the Pacific Northwest and which reasonably could have been expected to naturally occur on the site. Examples include trees such as Douglas Fir, western hemlock, western red cedar, alder, big -leaf maple; shrubs such as willow, elderberry, salmonberry, and salal; and herbaceous plants such as sword fern, foam flower, and fireweed. New Development means land disturbing activities, including Class IV General Forest Practices that are conversions from timber land to other uses; structural development, including construction or installation of a building or other structure; creation of hard surfaces; and subdivision, short subdivision and binding site plans, as defined and applied in Chapter 58.17 RCW. Projects meeting the definition of redevelopment shall not be considered new development. Refer to Appendix 1 for a definition of hard surfaces. New Permittee means a city, town, or county that is subject to the Western Washington Municipal Storm water General Permit and was not subject to the permit prior to July 1, 2019. New Secondary Permittee means a Secondary Permittee that is covered under a municipal stormwater general permit and was not covered by the permit prior to July 1, 2019. NOI means Notice of Intent. Notice of Intent (NOI) means the application for, or a request for coverage under, a General Permit pursuant to WAC 173-226-200. Notice of Intent for Construction Activity means the application form for coverage under the Construction stormwater General Permit. Notice of Intent for Industrial Activity means the application form for coverage under the Industrial stormwater General Permit. NPDES means National Pollutant Discharge Elimination System. Western Washington Phase 1I Municipal Page 52 of 56 stormwater Permit -August 1, 2019 Outfall means a point source as defined by 40 CFR 122.2 at the point where a discharge leaves the Permittee's MS4 and enters a surface receiving waterbody or surface receiving waters. Outfall does not include pipes, tunnels, or other conveyances which connect segments of the same stream or other surface waters and are used to convey primarily surface waters (i.e., culverts). Overburdened Community means minority, low-income, tribal, or indigenous populations or geographic locations in Washington State that potentially experience disproportionate environmental harms and risks. This disproportionality can be as a result of greater vulnerability to environmental hazards, lack of opportunity for public participation, or other factors. Increased vulnerability may be attributable to an accumulation of negative or lack of positive environmental, health, economic, or social conditions within these populations or places. The term describes situations where multiple factors, including both environmental and socio-economic stressors, may act cumulatively to affect health and the environment and contribute to persistent environmental health disparities. Permittee unless otherwise noted, the term "Permittee" includes city, town, or county Permittee, Co - Permittee, New Permittee, Secondary Permittee, and New Secondary Permittee. Physically Interconnected means that one MS4 is connected to another storm sewer system in such a way that it allows for direct discharges to the second system. For example, the roads with drainage systems and municipal streets of one entity are physically connected directly to a storm sewer system belonging to another entity. Project site means that portion of a property, properties, or right-of-ways subject to land disturbing activities, new hard surfaces, or replaced hard surfaces. Refer to Appendix 1 for a definition of hard surfaces. QAPP means Quality Assurance Project Plan. Qualified Personnel means someone who has had professional training in the aspects of stormwater management for which they are responsible and are under the functional control of the Permittee. Qualified Personnel may be staff members, contractors, or volunteers. Quality Assurance Project Plan means a document that describes the objectives of an environmental study and the procedures to be followed to achieve those objectives. RCW means the Revised Code of Washington State. Receiving Waterbody or Receiving Waters means naturally and/or reconstructed naturally occurring surface water bodies, such as creeks, streams, rivers, lakes, wetlands, estuaries, and marine waters, or groundwater, to which a MS4 discharges. Redevelopment means, on a site that is already substantially developed (i.e., has 35% or more of existing hard surface coverage), the creation or addition of hard surfaces; the expansion of a building footprint or addition or replacement of a structure; structural development including construction, installation or expansion of a building or other structure; replacement of hard surface that is not part of a routine maintenance activity; and land disturbing activities. Refer to Appendix 1 for a definition of hard surfaces. Regulated Small Municipal Separate Storm Sewer System means a Municipal Separate Storm Sewer System which is automatically designated for inclusion in the Phase II stormwater permitting program by Western Washington Phase it Municipal Page 53 of 56 Storrnwater Permit -August 1, 2019 its location within an Urbanized Area, or by designation by Ecology and is not eligible for a waiver or exemption under S1.C. Runoff is water that travels across the land surface and discharges to water bodies either directly or through a collection and conveyance system. See also "Stormwater." SAM means Stormwater Action Monitoring Secondary Permittee is an operator of a regulated small MS4 which is not a city, town or county. Secondary Permittees include special purpose districts and other public entities that meet the criteria in S1.B. Sediment/Erosion-Sensitive Feature means an area subject to significant degradation due to the effect of construction runoff, or areas requiring special protection to prevent erosion. See Appendix 7 Determining Construction Site Sediment Damage Potential for a more detailed definition. Shared Water Bodies means water bodies, including downstream segments, lakes and estuaries that receive discharges from more than one Permittee. Significant Contributor means a discharge that contributes a loading of pollutants considered to be sufficient to cause or exacerbate the deterioration of receiving water quality or instream habitat conditions. Small Municipal Separate Storm Sewer System means an MS4 that is not defined as "large" or "medium" pursuant to 40 CFR 122.26(b)(4) & (7) or designated under 40 CFR 122.26 (a)(1)(v). Source Control BMP means a structure or operation that is intended to prevent pollutants from coming into contact with stormwaterthrough physical separation of areas or careful management of activities that are sources of pollutants. The SWMMWW separates source control BMPs into two types. Structural Source Control BMPs are physical, structural, or mechanical devices, or facilities that are intended to prevent pollutants from entering stormwater. Operational BMPs are non-structural practices that prevent or reduce pollutants from entering stormwater. Stormwater means runoff during and following precipitation and snowmelt events, including surface runoff, drainage or interflow9 Stormwater Action Monitoring (SAM) is the regional stormwater monitoring program for Western Washington. This means, for all of Western Washington, astormwater-focused monitoring and assessment program consisting of these components: status and trends monitoring in small streams and marine nearshore areas, stormwater management program effectiveness studies, and source identification projects. The priorities and scope for SAM are set by a formal stakeholder group that selects the studies and oversees the program's administration. Stormwater Associated with Industrial and Construction Activity means the discharge from any conveyance which is used for collecting and conveying stormwater, which is directly related to manufacturing, processing or raw materials storage areas at an industrial plant, or associated with clearing, grading and/or excavation, and is required to have an NPDES permit in accordance with 40 CFR 122.26. Stormwater facility retrofits means both: projects that retrofit existing treatment and/or flow control facilities; and new flow control or treatment facilities or BMPs that will address impacts from existing development. Western Washington Phase I! Municipal Page 54 of 56 Stormwater Permit -August 1, 2019 Stormwater Management Program taw P) means a set of actions and activities designed to reduce the discharge of pollutants from the MS4 to the MEP and to protect water quality, and comprising the components listed in S5 (for cities, towns, and counties) or S6 (for Secondary Permittees) of this Permit and any additional actions necessary to meet the requirements of applicable TMDLs pursuant to S7 — Compliance with TMDL Requirements, and S8— Monitoring and Assessment. Stormwater Treatment and Flow Control BMPs/Facilities means detention facilities, permanent treatment BMPs/facilities; and bioretention, vegetated roofs, and permeable pavements that help meet Appendix 1 Minimum Requirements #6 (treatment), #7 (flow control), or both. Surface Waters includes lakes, rivers, ponds, streams, inland waters, salt waters, and all other surface waters and water courses within the jurisdiction of the State of Washington. SWMMWW or Stormwater Management Manual for Western Washington means Stormwater Management Manual for Western Washington (2019). SWMP means Stormwater Management Program. TMDL means Total Maximum Daily Load. Total Maximum Daily Load (TMDL) means a water cleanup plan. A TMDL is a calculation of the maximum amount of a pollutant that a water body can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL is the sum of the allowable loads of i single pollutant from all contributing point and nonpoint sources. The calculation must include a margin of safety to ensure that the water body can be used for the purposes the state has designated. The calculation must also account for seasonable variation in water quality. Water quality standards are set by states, territories, and tribes. They identify the uses for each water body, for example, drinking water supply, contact recreation (swimming), and aquatic life support (fishing), and the scientific criteria to support that use. The Clean Water Act, Section 303, establishes the water quality standards and TMDL programs. Tributary Conveyance means pipes, ditches, catch basins, and inlets owned or operated by the Permittee and designed or used for collecting and conveying Stormwater. UGA means Urban Growth Area. Urban Growth Area (UGA) means those areas designated by a county pursuant to RCW 36.70A.110. Urbanized Area is afederally-designated land area comprising one or more places and the adjacent densely settled surrounding area that together have a residential population of at least 50,000 and an overall population density of at least 1,000 people per square mile. Urbanized Areas are designated by the U.S. Census Bureau based on the most recent decennial census. Vehicle Maintenance or Storage Facility means an uncovered area where any vehicles are regularly washed or maintained, or where at least 10 vehicles are stored. Water Quality Standards means Surface Water Quality Standards, Chapter 173-201A WAC, Groundwater Quality Standards, Chapter 173-200 WAC, and Sediment Management Standards, Chapter 173-204 WAC. Waters of the State includes those waters as defined as "waters of the United States" in 40 CFR Subpart 122.2 within the geographic boundaries of Washington State and "waters of the State" as defined in Western Washington Phase 11 Municipal Page 55 of 56 Stormwater Permit- August 1, 2019 Chapter 90.48 RCW which includes lakes, rivers, ponds, streams, inland waters, underground waters, salt waters and all other surface waters and water courses within the jurisdiction of the State of Washington. Waters of the United States refers to the definition in 40 CFR 122.2. Western Washington Phase I! Municipal Page 56 of 56 Storm water Perm it -August 1, 2019