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Prelim Drainage ReportTAHOMA VALLEY GOLF & COUNTRY CLUB IMPROVEMENTS Preliminary Drainage Report Yelm, WA DECEIVED JAN D 4 1007 ~ Cons ufring Fn gineers 4200 6th Avenue, Suite 309 Lacey, WA 98503 KPFF Project No. 405060 January 3, 2007 ~-, r-, ~~ u ~J n n v u r, n ~J r, U n U n .~ LJ l U ~~ u u Preliminary Drainage Report Tahoma Valley Golf and Country Club Improvements Yelm, Washington January 20®7 Project Information Project: Terra Valley Golf and Country Club Prepared for: TVGCC LLC Contact: Doug Bloom 4200 Gtr' Ave. SE, Ste. 301 Lacey, WA 98503 (360) 493-6002 Reviewing Agency Jurisdiction: City of Yelm, Washington Project Number: Project Contact: James E. Gibson, P.E. Project Engineer Prepared by: KPFF Consulting Engineers 4200 6~' Ave. SE, Ste. 309 Lacey, WA 98503 (360) 292-7230 FAX (360) 292-7231 Contact Mark Steepy, P.E. KPFF Project: 406060 File Number: i:\2006\406060.10\documents\tvgc_pdr.rtf PROJECT ENGINEERS CERTIFICATION: I hereby certify that this Preliminary Drainage Report for the Terra Valley Golf and Country Club in Yelm Washington has been prepared by me or under my supervision and meets the intent of the City of Yelm Development Guidelines and Washington State Department of Ecology (WSDOE) Stormwater Management Manual for the Puget Sound Basin unless noted otherwise, and normal standards of engineering practice. I understand that the jurisdiction does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities designed for this development. ~,A. ~, '" ~3 EY,PIRES 2/27 i TABLE OF CONTENTS APPENDICES PART I STORM DRAINAGE REPORT ..................................................................... ...................1 APPcndix I - Prcliminary Drainage Calculations SECTION 1 - PROPOSED PROSECT DESCRIPTION ......._ ................................. ...................1 SECTION 2 - EXISTING CONDTTiONS ................................__............................ ...................4 APPendix U -Preliminary Drainage and TESC Plan SECTION 3 - INFTLTRATfON RATES/SOILS REPORT ....................................... ............ _.....5 SECTION 4 - WELLS AND SEPTIC SYSTEMS .................................................... ...................5 Appendix III -Facility Summary Forms SECTION 5 - FUEL T.4'~IICS ................................................................................... ...................5 SECTION 6 - Si1B-BASIN DESCRIPTION ...........................__......._...........__.... ....._............5 APPendix N -FEMA FIRM Map SECTION 7 - ANALYSIS OF 100-YEAR FLOOD ................................................ ...................6 Appendix V -Vicinity Map SECTION 8 - AESTHETIC CONSIDERATIONS FOR FACII.ITIES ..................... ...................6 SECTION 9 - DOWNSTREAM ANALYSIS AND FACII.ITY SIZIIJG ................. ...................6 Appendix Vi -Aqua-Swirl literaturc SECTION 10 -COVENANTS, DEDICATIONS, EASEMENTS .............................. ...................6 PART II-EROSION CON'PROL REPORT .................................................................................7 APPendix VII-Maintenance SECTION 1 - CONSTRUCTION SEQUENCE AND PROCEDURE ..................... ......:............7 A greement SECTION 2 - TRAPPING SEDIMENT ................................................................... ...................7 SECTION i - PERMANENT EROSION CONTROL & SITE RESTORATTON .... ...................8 SECTION 4 - GEOTECHNICAL ANALYSIS AND REPORT..._............_.__._._ . ...................8 SECTION 5 - INSPECTION SEQUENCE ...................................................._........ ..._..............8 SECTION 6 - CONTROL OF POLLUTANTS OTHER THAN SEDIMENTS ....... ..........._.._.. 8 PART III -MAINTENANCE PLAN ........................................................................... ...................9 SECTION 1 - REQUII2ED MAI'.VTENANCE.._ ..................................................... .................11 SECTION Z - RESPONSIBLE ORGANIZATION .................................................. ................. 19 SECTION 3 - VEGETATION MANAGEMENT PLAN ..._ .................................... .................19 SECTION 4. SOURCE CONTROL _......._ .................................._........__........_.. .................19 ii r, u ~, ~i r, ~i r-, ~i ~~ r, ~~ r, ~I u r, ~J -, ~~ ,-, ~J ~, v ~, u ~, zr Part I Preliminary Storm Drainage Report r, r, -, r, u r, J r, U r, ~, J r, iJ ~J `-1 ~J PQYt 1 PY2ZZYYlZ72Ql'y .S`tOYY12 DYQZ12Qg2 R21JOYZ Terra Valley Golf and Country Club Preliminary Drainage Report PART I STORM DRAINAGE REPORT SECTION 1 - PROPOSED PROJECT DESCRIPTION Project Proponent: TVGCC LLC 4200 6t1' Ave. SE, Ste. 301 Lacey, WA 98503 (360) 493-6002 Parcel Numbers: 21724440100 Total Site Area: 2.55 Acres Zoned: P/ OS Site Address: 12545 Mossman St SE, Yelm, WA 98597 Required Permits: Grading, Utility, Building, Plumbing, Electrical, Mechanical etc. Section, Township, R ange:Section 24, Township 17 North, Range 1 East, W.M., Thurston County, WA Site Location: The site is located in Yelm, Washington and is bordered on the north by Mossman Street SE, and surrounded by an existing golf course on all other sites. Project Overview: The proposal is to improve existing clubhouse into a new one story 3,400 sf clubhouse with an associated parking. Three new entrances from Mossman Street will access the site. The development of the proposed site will be constructed in one phase (with an °~cepticn cf campletion cf I:Ycssman Street frontage i.-.:prove.-..ents, :which :rill b~ deferred as per agreement between the City and the developer) and will include appropriate erosion control measures as needed, grading, storm drainage improvements, frontage improvements and extension of underground utilities including water and sanitary sewer. Storm Drainage Improvements: The completed project will create approximately 1.29 acres of lot impervious area, O.1 ac of roof impervious area, O.1 ac of pond area and 0.24 acres of disturbed pervious area (landscaping). Completion of Mossman Street SE frontage improvements will be deferred as per agreement between the City and the developer. All project impervious areas {roads, walks, roofs) are accounted for below: KPFF Consulting Engineers Page 1 December 2006 r, Terra Valley Golf and Country Club Preliminary Drainage Report n u u n rJ `~ ~~ Table ] Post-Development Basin Area Summary Basin A Basin B Basin C Total Im envious Roof 0 ac 0.10 ac O ac 0.10 ac Im envious Roadwa Sidewalk on-site 0 ac 0.64 ac 0.65 ac 1.29 ac ~ Im envious Roadwa Sidewalk off-site 0.72 ac O ac O ac 0.72 ac Disturbed Pervious on-site O ac 0.15 ac 0.09 ac 0.24 ac Disturbed Pervious off-site 0.10 ac O ac O ac 0.10 ac Im envious and 0 ac 0 ac 0.1 ac O.1 ac Total 0.82 ac 0.89 ac 0.84 ac 2.55 ac ~ __- Stormwater Treatment: - "AquaShield-Aqua-SwirlT"' Model AS-2 CFD": i ~J Stormwater treatment will be obtained by utilization of AquaShield AS-2 Aqua Swirl ,~ application (approved by the Department of Ecology's "Emerging Technologies Program GULD for Pre-treatment) for the existing developed basins prior to '~ discharge through infiltration pond sized to infiltrate the 100 year-24 hour storm event. The Aqua-Swir1T~ Concentrator Conveyance Flow Diversion System provides full treatment for the most contaminated "first flush," while the cleaner peak storm v flow is diverted and channeled through the main conveyance pipe. Many regulatory agencies are establishing "water quality treatment flow rates" for their areas based '~ on the initial movement of pollutants into the storm drainage system. :~ The operation begins when stormwater enters the Aqua-Swir1T~ through a tangential ~ inlet pipe which produces a circular (or vortex) flow pattern that causes -i contaminates to settle. Because stormwater flow is intermittent by nature, the Aqua- Swir1T^i Concentrator retains water between storm events providing both "dynamic ,~ and quiescent" settling of inorganic solids. The dynamic settling occurs during each storm event, while the quiescent settling takes place between successive storms. A combination of gravitational and hydrodyriamic drag forces encourages the solids to drop out of the flow and migrate to the center of the chamber where velocities are the lowest, as shown from extensive CFD modeling. It is anticipated that due to flat grades and high soils permeability landscaping areas ~, tributary to treatment facility s=ill not produce appreciable runoff and by including them in calculations we input additional safety margin. n u u Basin "A": Basin "A" includes Mossman St SE fronting the project which is subject to future improvements. Runoff from this area will sheet flow to a series of street side catch basins and be directed to Aqua-Swir1TM Model AS-2 CFD for treatment and into infiltration pond for infiltration to groundwater. The Manual requires 6-month/24- hour event to be treated. Aqua-SwirlT" Model AS-2 CFD has capacity to treat flows up KPFF Consulting Engineers Page 2 December 2006 Terra Valley Golf and Country Club Preliminary Drainage Report ~ to 1.1 cfs which exceeds (by 46%) flows generated by 6-month/24-hour event for developed conditions. Preliminary treatment calculations are provided in Appendix I. n ~ Basin "B": ~J Basin "B" includes proposed 3,400 sf clubhouse with associated parking and `~ landscaping in western part of the site. Runoff from this area will sheet flow to a L( series of catch basins and be directed to Aqua-SwirlT"2 Model AS-2 CFD for treatment and into infiltration pond for infiltration to groundwater. The Manual requires 6- ~i month/24-hour event to be treated. Aqua-Swir1T'1 Model AS-2 CFD has capacity to treat ~j flows up to 1.1 cfs which exceeds (by 46%) flows generated by 6-month/24-hour event for developed conditions. Preliminary treatment calculations are provided in r~ Appendix I. Roof runoff: ~ Roof runoff from the proposed building will be collected by 6" dia roof drains, flow through underwalks into parking lot where it will be intercepted by catch basins and ,~ directed to Aqua-Swir1T"' Model AS-2 CFD for treatment. ~l Basin "C": '~ Basin "B" includes proposed parking with associate landscaping in eastern part of the site. Runoff from this area will sheet flow to a series of catch basins and be directed to Aqua-SwirlTr' Model AS-2 CFD for treatment and into infiltration pond for infiltration to groundwater. The Manual requires 6-month/24-hour event to be treated. Aqua-Swir1T"' Model AS-2 CFD has capacity to treat flows up to 1.1 cfs which `~ exceeds (by 46%) flows generated by 6-month/24-hour event for developed conditions. Preliminary treatment calculations are provided in Appendix I. ~ Stormwater storage and infiltration requirements are based on the 1992 edition of the WSDOE Stormwater Management Manual using a 100-year/24-hour storm event. Preliminary storage and infiltration calculations are provided in Appendix I. ,-r StormShed modeling software was used to size the storage and infiltration facilities. ~ Roof runoff will be treated by Aqua-Swir1T"' Model AS-2 CFD and discharged into the infiltration pond. n Basin "A": ~J r Stormwater runoff treated by Aqua-Swir1T"' Model AS-2 CFD will be stored in the infiltration pond prior to infiltration to groundwater. Storage requirements were ~ calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm U KPFF Consulting Engineers Page 3 December 2D06 n >J r, Terra Valley Golf and Country Club Preliminary Drainage Report ~1 ~ within 48 hours. The proposed pond volume of 9,466 cf exceeds (by 61%) the '-~ minimum storage requirement of 5,775 cf for basins A, B & C. rJ `~ Basin "B": I u Stormwater runoff treated by Aqua-SwirlTr= Model AS-2 CFD will be stored in.the '~ infiltration pond prior to infiltration to groundwater. Storage requirements-were ,~ calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm r, within 48 hours: The proposed pond volume of 9,466 cf exceeds (by 61%) the ~ minimum-modeling requirement of 5,775 cf for basins A, B 8c C. ,-, Basin "C": '~ Stormwater runoff treated by Aqua-SwirIT61 Model AS-2 CFD will be stored in the ~ infiltration pond prior to infiltration to groundwater. Storage requirements were calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual i-1 requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm within 48 hours. The proposed pond volume of 9,466 cf exceeds (by 61%) the minimum-modeling requirement of 5,775 cf for basins A, B & C. J ~~ J ,~ Stora a Ca acit Summa Impervious Area Disturbed Pervious Area Storage til Re uired Storage Provided Basins A, B 8v C 2.21 ac 0.34 ac 5,775 cf 9,466 cf TOTAL 2.21 ac 0.34 ac 5,775 cf 9,466 cf ~1 (1) Based on StormShed modeling software for the 100-year/24-hour storm event for 20-in/hr infiltration rate For whole basin (basins A, B and C) SECTION 2 -EXISTING CONDITIONS The project site is currently occupied by an existing clubhouse and two outbuildings '-' which will be demolished prior to beginning of construction. The site subject to ~J development is about 2.22 acres in size and is fairly flat with gentle slopes to the northeast with low elevations of about 349 ft located easterly on the site and high ~? elevation of about 352 located southwesterly. The site is accessible from Mossman ,~ Street SE, which bounds the project to the north. The project is surrounded by an existing golf course, which it's intended to serve. Vegetation consists of small group ~ of conifer trees surrounding in the eastern part of the site. On-site soils were well drained and formed in glacial outwash. LJ KPFF Consulting Engineers Page 4 December 2006 rt LJ Terra Valley Golf and Country Club Preliminary Drainage Report J r1 There are no creeks, lakes, ponds, springs, wetlands, ravines, gullies, steep slopes or other environmentally sensitive areas identified onsite or down gradient of the subject property. `I The site is located in an aquifer sensitive area, according to the 1986 Thurston County Comprehensive Plan M-8. The site is located in a wellhead protection area. J SECTION 3 -INFILTRATION RATES/SOILS REPORT '~ The Soil Conservation Service (SCS) Soil Survey of Thurston County classifies onsite ~~ soils as Spanaway (1 10) series. n The design infiltration rate of 20 in/hr was assumed for the purposes of this study. This is a conservative rate based on actual infiltration rates observed in the field. ~ SECTION 4 -WELLS AND SEPTIC SYSTEMS '-~ The site was served by a single well located centrally on site, which will be abandoned according to the WA DOE rules and regulations prior to beginning of r,. construction. ~ The site was served by a single septic system, which will be removed in accordance with Thurston County Department of Health standards. No records were found of '~ any other 'septic system on-site or within 100 feet from proposed infiltration facility. u Any septic system found will be removed according with Thurston County Department of Health standards. r, u SECTION 5 - FUEL TANKS No fuel tanks were located during site inspection or during soils work. Additionally, ~ a review of the DOE's Leaking Underground Storage Tank (LUST) list did not indicate any existing or abandoned fuel tanks on the project site. SECTION 6 - SUB-BASIN DESCRIPTION u ,~ The project site is located in the Yelm Creek Drainage Basin per Thurston County Comprehensive Map M-4. During site investigation and soils analysis, it appeared that all onsite stormwater runoff is contained onsite. u There does not appear to be any significant existing offsite drainage to the property. r' As discussed previously, the proposed development was divided into three drainage u basins for the purposes of this study. The facilities in this basin consist of Aqua- Swir1T"I ]Iodel AS-2 CFD to provide stormwater treatment and infiltration pond to `-' provide storage and infiltration of the treated stormwater to the groundwater. u No hazardous materials handling is anticipated in the area tributary to the storm drainage facilities. u u KPFF Consulting Engineers Page 5 December 2006 r~ LJ r, u ~J r, v J -~ ~I r, u r, u u u ~J ~l ~J ~~ u u r, u v u Terra Valley Golf and Country Club Preliminary Drainage Report SECTION 7 - ANALYSIS OF 100-YEAR FLOOD This project does not contain a stream onsite and has not been identified as a 100- year flood hazard area. A FEMA FIRM Map is included in Appendix IV. SECTION 8 - AESTHETIC CONSIDERATIONS FOR FACILITIES All disturbed pervious areas will be vegetated and landscaped. Fences if required for infiltration pond will be vegetated along with other "unsightly" features. Landscaping plan will be submitted to the City. SECTION 9 - DOWNSTREAM ANALYSIS AND FACILITY SIZING Calculations for the project's stormwater treatment, storage, and infiltration facilities are provided in Appendix I of this report. All calculations correspond to the Preliminary Drainage and TESC Plan, which can be found in Appendix II of this report. Since all stormwater will be infiltrated onsite, a downstream analysis was deemed unnecessary. SECTION 10 -COVENANTS, DEDICATIONS, EASEMENTS Onsite drainage facilities including pipes, wet ponds and infiltration ponds will require routine maintenance. The maintenance manual prepared for the project will list the maintenance requirements. A copy of the completed Maintenance Manual can be supplied to the City upon completion of the project. KPFF Consulting Engineers Page 6 December 2006 Terra Valley Golf and Country Club Preliminary Drainage Report J u PART II -EROSION CONTROL REPORT ~ SECTION 1 - CONSTRUCTION SEQUENCE AND PROCEDURE ~J The proposed commercial development will include site grading and erosion control r' measures designed to contain silt and soil within the project boundaries during ~ construction until permanent vegetation and site improvements are in place. Erosion/sedimentation control shall be achieved by a combination of structural/vegetative cover measures and construction practices tailored to fit the u site. u ~~ ~J r, u r, u s v u ,_.i ~~ ~~ J ~J -~ ~J Best Management Practices (BMP's) will be employed to properly clear and grade the site and to schedule construction activities. Before any construction begins onsite, erosion control facilities shall first be installed. The planned construction sequence is as follows: 1. Schedule preconstruction conference with the city, contractor, project engineer, and construction-staking surveyor. 2. Install rock construction entrance. Use 4" to 8" diameter spalls with 12" minimum depth. 3. Install filter fabric fencing in the locations shown on the plans. 4. Clear site (grubbing and rough grading). 5. Maintain equipment and water supply far dust control. 6. Designate an area for washing concrete trucks to control the runoff and eliminate entry into the storm drainage system. 7. Install underground utilities (water, sewer, storm). 8. Provide inlet protection around all new catch basins. 9. Construct roadway and parking and install landscaping, sod and/or seed, and mulch all disturbed areas. 10. Maintain all erosion control facilities until the entire site is stabilized and silt runoff ceases. SECTION 2 - TRAPPING SEDIMENT Filter fabric fencing gill to installed to trap sediment before runoff exits the site. In addition, inlet protection will be installed around all existing and new catch basins to filter out sediment before runoff enters the storm system. A stabilized construction entrance will be installed to prevent construction vehicles from tracking soil onto roadways. If sediment is tracked offsite, it shall be swept or shoveled from paved surfaces on a daily basis, so that it is not washed into existing catch basins or other storm drainage facilities. During the rainy season from November 1 through March 31, the contractor must cover any disturbed areas greater that 5,000 SF in size if they will be unworked for more than 12 hours. Mulch, sodding, or plastic covering shall be used to prevent erosion in these areas. KPFF Consulting Engineers Page 7 December 2006 u r, f-, ~~ -, r, ~~ u ~s J r, -~ ~a Part II Erosion Control Report U Terra Valley Golf and Country Club Preliminary Drainage Report SECTION 3 - PERMANENT EROSION CONTROL Sc SITE RESTORATION ~i ~ All disturbed areas will be paved with asphalt, covered by buildings, or landscaped with grass, shrubbery, or trees per the landscaping plans. SECTION 4 - GEOTECHNICAL ANALYSIS AND REPORT r, u No slops steeper than 15% are present on site or in vicinity therefore geotechnical analysis was deemed unnecessary. r, ,J SECTION 5 - INSPECTION SEQUENCE ~~ In addition to required City inspections, the Project Engineer will inspect facilities ~ related to stormwater treatment, erosion control, storage, and conveyance during construction. At a minimum, the following items shall be inspected at the time r, specified: `~ 1. The erosion control facilities shall be inspected before the start of clearing and r, grading to ensure the following structures are in place: a. Construction Entrance ~ b. Filter Fabric Fences ~, c. Inlet protection of new catch basins '-' 2. The conveyance systems will be inspected after construction of the facilities, but before project completion to ensure the following items are in working ,-, order: iJ a. Pavement Drainage r' b. Catch Basins u c. Conveyance Piping d. Roof Drain Piping L} 3. The infiltration galleries shall be inspected during construction to ensure that the facility is constructed to design specifications. r-, J 4. The per**~s_ent site res*_oration measures shall be ir_spec*.ed after 1~~z3scapir~g is completed. -~ ~ A final inspection shall be performed to verify final grades, settings of structures and all necessary information to complete the Engineer's Construction Inspection Report ,~ Form. This form must be completed prior to final public works construction approval. u SECTION 6 - CONTROL OF POLLUTANTS OTHER THAN SEDIMENTS ~ The contractor will be required to designate a washdown area for concrete trucks as well as a temporary stockpile area for construction debris. Catch basin inlet protection and filter fabric fencing shall remain in place until construction on the J site is complete. ,J KPFF Consulting Engineers Page 8 December 2006 r, ~~ r-, r, r, ~, ~~ r, r-, v r, ~~ r, ~i r, ~~ ~, -, r, -, ~~ Part III Maintenance Plan r-, ~J ~-~ ~J J v u n J ~J v u r-, u -~ 41 ~i n ~~ n ~J Terra Valley Golf and Country Club Preliminary Drainage Report PART III -MAINTENANCE PLAN INSTRUCTIONS FOR MAINTENANCE OF STORM DRAINAGE FACILITIES The following pages contain maintenance needs for most components that are part of the drainage system. A checklist should be completed for all system components according to the following schedule: 1. Monthly from November through April 2. Once in late summer (preferably September) 3. After any major storm (use 1" in 24-hours as a guideline) items marked "S" only. Using photocopies of these pages, check off the problems identified with each inspection. Add comments on problems found and actions taken. Keep these "checked" sheets in a file, as they will be used to write the annual report (due in May of each year). Some items do not need to be checked with every inspection. Use the suggested frequency at the left of each item as a guideline for the inspections. The City of Yelm is available for technical assistance. Do not hesitate to call, especially if it appears that a problem may exist. KPFF Consulting Engineers December 2006 Page g n v ~J r't i ~J ,J n J n v r, ~J iJ r-, u' ~1 ~1 ~1 n ~J ~i I r-~ U Terra Valley Golf and Country Club Preliminary Drainage Report ATTACHMENT "A": MAINTENANCE PROGRAM COVER SHEET Inspection Period: Number of Sheets Attached: Date Inspected: Name of Inspector: Inspector's Signature: KPFF Consulting Engineers December 2006 Page 10 r, Terra Valley Golf and Country Club Preliminary Drainage Report u ~-~ ~J r~ ,~ rl i~ 1 t~ r~ r~ l~ n u n 1 1 ~J ~J n r1 r~ J SECTION 1 - REQUIRED MAYNTENANCE The drainage facilities will require occasional maintenance. The checklists below are the minimum maintenance requirements and inspection frequencies. Maintenance Checklist for Conveyance Systems (Pipes and Swales) Frequency Drainage ti Problem Conditions to Check For Conditions That Should System Req'd Exist Feature M.S. Pipes ~ Sediment & Accumulated sediment that Pipe cleaned of al] debris exceeds 20 % of the diameter of sediment and debris. the pipe. M ti Vegetation Vegetation that reduces free All vegetation removed so movement of water through pipes. water flows freely. A ~ Damaged Protective coating is damaged, Pipe repaired or replaced: (rusted, rust is causing more than 50% bent or deterioration to any part of pipe. crushed) M ~ Any dent that significantly Pipe repaired or replaced. impedes flow (i.e., decreases the cross section azea of pipe by more then 20 % ). M ~ Pipe has major cracks or teazs Pipe repaired or replaced. allowing groundwater Leakage. M.S. Swales Trash & Dumping of yard wastes such as Remove trash and debris debris grass clippings and branches into and dispose as prescribed Swale. Accumulation of non- by City Waste degradable materials such as Management Section. glass, plastic, metal, foam and coated paper. M Sediment Accumulated sediment that Swale cleaned of all buildup exceeds 20% of the design depth. sediment and debris so that it matches design. M Veeetation Grass cover is spazse and weedy Aerate soils and reseed not or aeeas aze overgrown with and mulch bare areas. growing or woody vegetation. Maintain grass height at a overgrown minimum of 6" for best stormwater treatment. Remove woody growth, recontour and reseed as necessary. M Conversion Swale has been filled in or If possible, speak with by owner to blocked by shed, woodpile, owner and request that incompatibl shrubbery, etc. Swale azea be restored. e use Contact City to report problem if not rectified voluntazily. A Swale does Water stands in Swale or flow A survey may be needed not drain velociTy is very slow. Stagnation to check grades. Grades occurs. need to be in 1°/a range if ossible. If ade is less KPFF Consulting Engineers December 2006 Page 11 Terra Valley Golf and Country Club Preliminary Drainage Report Frequency Drainage ~ Probiem Conditions to Check For Conditions That Should System Req'd Exist Feature I than 1%, underdrains may need to be installed. [fyou are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance. Comments: Key. A =Annual (bfarch or April preferred) M= Monthty (see schedule) 5 = After m jor storms KPFF Consulting Engineers Page 12 December 2006 r, Terra Valley Golf and Country Club Preliminary Drainage Report rl cJ rl J n u r~ ~1 r~ i tJ ~l [J n i~ n tJ ~_ 1 r~ r~ L~ ~-~ ATTACHMENT "A" (CONTINUED) Maintenance Checklist for Catch Basins and Inlets Frequency Drainage ~/ Problem Conditions to Check For Conditions That System Should Exist Feature M.S. General J Trash, debris and Trash or debris in front of No trash or debris sediment in or on the catch basin opening is located basin blocking capacity by more immediately in than 1D%. front of catch basin opening. Grate is kept clean and allows water to enter. M J Sediment or debris (in the No sediment or basin) that exceeds 1/3 the debris in the catch depth from the bottom of basin. Catch basin basin to invert of the is dug out and lowest pipe into or out of clean. the basin. M.S. ~ Trash or debris in any inlet Inlet and outlet or pipe blocking more than pipes free of trash 1/3 of its height. or debris. M ~/ Structural Comer of frame extends Frame is even with damage to frame more than 3!4" past curb curb. andlor tap slab face into the street (if applicable). M J Top slab has holes larger Top slab is free of than 2 square inches or holes and cracks. cracks wider than 1/4" (intent is to make sure all material is running into the basin). M J Frame not sitting flush on Frame is sitting top slab, i.e., separation of flush on top slab. more than 3; 4" of the frame from the top slab. A J Cracks in basin Cracks wider than 1; 2" and Basin replaced or walls~bottom longer than 3', any repaired to design evidence of soi] particles standazds. Contact entering catch basin a professional through cracks or engineer for maintenance person judges evaluation. that structure is unsound. A J Cracks wider than ll2" and No cracks more longer than 1' at the j oint than 1; 4" wide at of any inleUoutlet pipe or the joint of any evidence of soil inlet,~outlet pipe. particles entering catch basin through cracks. i ~ KPFF Consulting Engineers Page 13 December 2006 U Terra Valley Golf and Country Club Preliminary Drainage Repon Frequency Drainage ~ Problem Conditions to Check For Conditions That System Should Exist Feature A tii Settlementlmis- Basin has sertled more than Basin replaced or alignment 1" or has rotated more than repaired to design 2" out of alignment. standards. Contact a professional engineer for evaluation. M.S. ~. Fire hazazd or Presence of chemicals such No color, odor or othec pollution as natural gas, oil and sludge. Basin is gasoline. Obnoxious dug out and clean. color, odor or sludge noted. M.S. ~/ Outlet pipe is Vegetation or roots No vegetation or clogged with growing in inleUoutlet pipe root grovr4h vegetation joints that is more than 6" present. tall and less than 6" apart. If you aze unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance. Com ents: Key:m A =Annual (March or .4pri7 preferred) M=Monthly (see schedule) 5 =?.Rer major storms KPFF Consulting Engineers Page 14 December 2006 ~, Terra Valley Golf and Country Club Preliminary Drainage Report f~ n i L~ 11 LJ r1 u u ~l i U v n n n L~ n U r~ LJ n r1 LJ M Sediment Any sediment and Clean out sump to trapping debris filling azea to design depth. area 10 % of depth from sump bottom-to-bottom of outlet pipe or obstructing flow into the connector pipe. One Time Sediment Stormwater enters Add a trapping area by trapping infiltration area directly constructing a sump area not without treatment. for settling of solids. present Segregate settling area from rest of facility. Contact City for guidance. M Rock d Sediment By visual inspection Replace gravel in rock filters and debris little or no water flows filter. through filter during heavy rainstorms. S Infiltratio Infiltration Standing Water in .Excavate bottom of n Failure Inspection Well After trench as necessary Trenches 48 hours after storm or but at least 3 feet. Overflow during Storms Replace with crushed rock. Check pretreatment systems for effectiveness. Check tributary area for sediment sources. If you are unsure whether a problem exists; please contact the Jurisdiction and ask for technical assistance. Comments: v .4 =Annual (March or April preferred) Vf =Monthly (see schedule) 5 = After m jor storms KPFF Consulting Engineers Page 16 December 2006 r~ U r, U n ~J r~7 ~J n L~ ~J '-l n n u t~ ~l ~~ LJ U LJ LJ n Ls U Terra Valley Golf and Country Club Preliminary Drainage Report ATTACHMENT "A" (CONTINUED) Maintenance Checklist for Grounds (Landscaping) Frequen Drainage ~I Problem Conditions to Check Conditions That Should cy System For Exist Feature I M General ~ Weeds Weeds growing in Weeds present in less (nonpoisono more than 20% of the than 5 % of the us) landscaped area landscaped area. (trees and shrubs . only). M ~ Safety Any presence of No poisonous vegetation hazard poison ivy or other or insect nests present poisonous vegetation in landscaped area. or insect nests. M,S J Trash or See Ponds Checklist. See Ponds Checklist. litter M,S ~ Erosion of Noticeable rills are Causes of erosion are Ground seen in landscaped identified and steps Surface areas. taken to slow down/spread out the water. Eroded areas are filled, contoured, and seeded. A Trees and J Damage Limbs or parts of Trim trees/shrubs to shrubs trees or shrubs that restore shape. Replace are split or broken trees/shrubs with which affect more severe damage. than 25 % of the total foliage of the tree or shrub. M ~/ Trees or shrubs that Replant tree, inspecting have been -hlow-n for injury to stem or down or knocked roots. Replace if over. severely damaged. A ~ Trees or shrubs, Place stakes and which are not rubber-coated ties adequately supported around young or are leaning over,. treesJshrubs for causing exposure of support. the roots. If yov are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance. Comments: v .4 =Annual (March or Apri] preferred) KPFF Consulting Engineers December 20D6 Page 17 ~~ J Terra Valley Golf and Country Club Preliminary Drainage Report n M = Monthly (see schedule) ~j S = After major storms ~J n r1 iJ r1 r~ U r1 LJ ri -~ LS r1 U r~ u U ~I r, 1J KPFF Consulting Engineers December 20D6 Page 78 -~ ~J ~, r~ u n v ~J n u r-, ~~ n ~1 n r, u r, ~~ u -~ ~J rt ~J ~J u ~J n v Terra Valley Golf and Country Club Preliminary Drainage Report SECTION 2 - RESPONSIBLE ORGANIZATION The Home Owners Association shall be responsible for the operations and maintenance of all onsite storm drainage facilities. SECTION 3 - VEGETATION MANAGEMENT PLAN All disturbed pervious areas on the site will be landscaped to provide an aesthetically pleasing environment. SECTION 4 - SOBJRCE CONTROL Warning signs (e.g., "Dump No Waste -Drains to Groundwater") will be embossed or painted on or adjacent to all storm drain inlets and will be repainted periodically as necessary. KPFF Consulting Engineers December 2006 Page 19 Appendix I Preliminary Drainage Calculations ~, ~ PRELIMINARY DRAINAGE CALCULATIONS r, The following calculations are based on the requirements contained in the 1992 ~ Washington State Department of Ecology (WSDOE) Stormwater Management Manual for the Puget Sound Basin. DESIGN AND BASIN INFORMATION SUMMARY: Ll Soil Classification (Soil Survey of Thurston County, WA): r`1 u SCS Soil Classification: Spanaway (110) Hydrologic Group: B ~' Design Infiltration Rate: 20 inches/hour i~ SCS Runoff Curve Number: (Table III-1.3 WSDOE Storm Manual) •-i ~ Post-developed (Lawns, 75% + grass cover): CN = 80 Post-development (impervious) CN = 98 Post-development wet ponds CN=100 `~ Rainfall Design Storms: (WSDOE Isopluvial Maps -App. AIII-1.1 of WSDOE Storm ~ Manual) J 6 month storm (64% of 2 yr. storm) = 1.28" 2 yr./24 hour storm = 2.0" ~ 10 yr./24 hour storm = 3.0" 100 yr. / 24 hour storm = 4.0" ~J rl v i_) r, v n ~J Post-Development Basin Area Summary Basin A Basin B Basin C Total Im ervious Roof 0 ac O.10 ac O ac 0.10 ac Im ervious Roadwa Sidewalk on-site O ac 0.64 ac 0.65 ac 1.29 ac Im ervious Roadwa Sidewalk off-site 0.72 ac O ac O ac 0.72 ac Disturbed Pervious on-site O ac 0.15 ac 0.09 ac 0.24 ac Disturbed Pervious ou-site 0.10 ac O ac O ac 0.10 ac Im ervious and O ac O ac O.1 ac O.1 ac Total 0.82 ac 0.89 ac 0.84 ac 2.55 ac r, ~ DETAILED CALCULATIONS: ~~ Stormwater Treatment: v Basin "A" `~ StormShed software was used to model the runoff from Mossman Street SE. The 6- ~J month storm event resulted in a peak flow rate of 0.1949 cfs, and a peak volume of 2,761 cf. The Manual requires 6-month/24-hour event to be treated. The 6-month r,, combined storm event for basins A, B and C resulted in a peak flow rate of 0.5984 ~ j cfs and a peak volume of 8,454 cf. Proposed Aqua-SwirlT"T Model AS-2 CFD has capacity to treat flows up to 1.1 cfs which exceeds (by 46%) flows generated by 6- r! month/24-hour event for fully developed conditions. ~-, Basin "B": `~ StormShed software was used to model the runoff from proposed clubhouse's roof, ,~ parking, sidewalks and landscaping located in western part of the site. The 6-month ~ storm event resulted in a peak flow rate of 0.2004 cfs, and a peak volume of 2,832 cf. The Manual requires 6-month/24-hour event to be treated. The 6-month combined ~ storm event for basins A, B and C resulted in a peak flow rate of 0.5984 cfs and a peak volume of 8,454 cf. Proposed Aqua-Swir1TM Model AS-2 CFD has capacity to treat flows up to 1.1 cfs which exceeds (by 46%) flows generated by 6-month/24-hour event for fully developed conditions. ~l Basin "C": u StormShed software was used to model the runoff from proposed parking and landscaping located in eastern part of the site. The 6-month storm event resulted in '-! a peak flow rate of 0.2033 cfs, and a peak volume of 2,856 cf. The Manual requires ,_; 6-month/24-hour event to be treated. The 6-month combined storm event for basins A, B and C resulted in a peak flow rate of 0.5984 cfs and a peak volume of 5,454 cf. ~ Proposed Aqua-Swir1TM Model AS-2 CFD has capacity to treat flows up to i. l cfs which exceeds (by 46°/) flows generated by 6-month/24-hear event far fully d~~eloped conditions. Total 6-month/24-hour peak rate for Basins A, B and C is: 0.1056 cfs + 0.2004 cfs + 0.2033 cfs ° 0.5093 cfs, which is less by 46% than maximum treating capacity of ,~ proposed Aqua-Swir1TM Model AS-2 CFD v rl v ~1 r, L~ ~J u n i r~ .~II ~J n u n rr ~~ rl J Stormwater Storage/Infiltration: See following StormShed software modeling output for stormwater storage results for the basins A, B and C Stora a Ca acit Summa Impervious Area Disturbed Pervious Area Storage 111 Re uired Storage Provided Basins A, B8sC 2.21 ac 0.34 ac 5,775 cf 9,466 cf TOTAL 2.21. ac 0.34 ac 5,775 cf 9,466 cf (1) Based on StormShed modeling software for the 100-year/24-hour storm event for 20-in/hr infiltration rate for whole basin (basins A, B and C) Infiltration Pond Storage Capacities From elevation 340 to 341 - 1,303 cf 341 to 342 - 1,854 cf 342 to 343 - 2,462 cf 343 to 344 - 3,126 cf 344 to 345 - 3,847 cf Total Infiltration Pond Storage Capacity: 9,466 cf Overboard 345 to 346 - 4,624 cf Basin "A": Stormwater runoff treated by Aqua-SwirlT"T Model AS-2 CFD will be stored in the infiltration pond prior to infiltration to groundwater. Storage requirements were calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm within 48 hours. The proposed pond volume of 9,466 cf exceeds (by 61%) the minimum-modeling requirement of 5,775 cf for basins A, B 8v C. Basin "B": Stormwater runoff treated by Aqua-SwirITM Model AS-2 CFD will be stored in the infiltration pond prior to infiltration to groundwater. Storage requirements were tJ r, calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual ~ requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm ,~ within 48 hours. The proposed pond volume of 9,466 cf exceeds (by 61%) the minimum-modeling requirement of 5,775 cf for basins A, B ~ C. iJ J Basin "C": `~ Stormwater runoff treated by Aqua-SwirlT"s Model AS-2 CFD will be stored in the LI infiltration pond prior to infiltration to groundwater. Storage requirements were calculated using 24-hour/ 100-year event. WSDOE Stormwater Management Manual ~ requires infiltration ponds to be able to infiltrate 100% of 100-year/24-hour storm Lj within 48 hours. The proposed pond volume of 9,466 cf exceeds (by 61%) the minimum-modeling requirement of 5,775 cf for basins A, B ~ C. J ~, ~~ ~, J ~, :~ J ~, ~, J ~, ~, J r, r, ~J v n r, u iJ ~,; iJ ~, J ~J rJ ~1 ~j ~l Supporting Basin Data: Basin A dev Event Summary Event :Peak Q (cfs) ,Peak T (hrs) ''•Hyd Vol (acft) ',Area (ac) ''.Method !,Raintype ;6 month 0 1949 8.01 0.0634 0.8200 SCS ;TYPElA 2 year ~ 0.3293 I ~ 8.00 ~~ O.l 110 ~~ 0.8200 ~ SCS TYPElA l0 year a 0.5181 ~ ~ 8.00 0.1766 ~, 0.8200 ;~ SCS TYPElA! 100 year 0.7087 8.00 0.2432 0.8200 SCS .TYPElA Record Id: basin a dev iDesign Method SCS 'Rainfall type TYPElA Hyd Intv ~ 10 00 min 2Peaking Factor ~ 484.00 'Abstraction Coeff 0.20 Pervious Area (AMC 2) 0.10 ac iDCIA 0.72 ac ~ i Pervious CN 80.00 DC CN j 98.00 Pervious TC ' 7.12 min DC TC ~ ~_w.._ _ _. __.~__. ___w~~~~ _____ 6.67 min _ _ --. __ ..... __..____.~- -_ ~___v.._ _..___.__.--- _-. __...._ Directly Connected CN Calc , _. ............ . . ~; Description SubArea Sub cn Impervious surfaces (pavements, roofs, etc) 0.72 ac 98.00 DC Composited CN (AMC 2) 98.00 ~~~~~~~_ ~~ - -~- -Directly Connected~TC Calc ~-~~ __~ __ ___ _._._ ~- ....~...~.___~_.. ~___ ~_,. ~ ____- __-~. __._ _,. ._~.._. r . ._~.~., , ~ Type Description j Length F Slope _Coeff Misc TT .Sheet ;Smooth Surfaces.. 0.011 ;16.00 ft 2.00% 0.01 l 0 2 00 in 0.35 mm z; Slxeet Smoct<'~ Surfaces.. 0.011 i~~0.00 `t ;;0.50% :0.0110 :x.00 in x.69 nun :Channel (interm) 'xn pipe X630.00 ft 0.50% 0.0090 '2.62 min Directly Connected TC _. .6.67 min 3 __.. __ _ __ _ Pervious CN Calc ] _. __ __ _ _ - .__.... p __ __. Descri tion r SubArea Sub cn ` Open spaces, lawns,parks (>75% grass) 0.10 ac 80.00 Pervious Composited CN (AMC 2) 80.00 Pervious TC Calc u ~J u ~~ J ~J ~J ~J ~~ v '~ ~J sort prairie Brass and lawns.: 0.15 Basin B dev Event Summary 1500 2.00 in '7.12 min Event ,Peak Q (cfs) ,Peak T (hrs) ;Ilya Vol (acft) :Area (ac) MMethod Raintype 6 month 0.2004 8.01 0.0650 0.8900 j SCS TYPElA 2 year 0.3431 8.00 0.1163 ~ 0.8900 ~ SCS ~TYPElA i l0 year 0.5455 8.00 0.1864 0.8900 SCS TYPElA '' 1100 year 0.7512 8.00 0.2580 ' 0.8900 ! SCS 'TYPElA', Record Id: basin b dev Design Method SCS Rainfall type s TYPElA 'Hyd Into ~ 10.00 min speaking Factor ! 484.00 ----------- ------ __,_ . r___~_~. _....~ .____ , -- sAbstraction Coeff i ---. _._.__..__..__.._ 0.20 !Pervious Area (AMC 2) 0.15 ac DCIA ~ 0.74 ac ___ '':Pervious CN '--~---~----- 80.00 DC CN _. 98.00 .Pervious TC ~~ ~ _____.____ ', 7.12 min IDC TC 6.13 min Directly Connected CN Calc _._ , _. _ Description SubArea Sub cn Impervious surfaces (pavements, roofs, etc) 0.74 ac ~ 98.00 DC Composited CN 98.00 Directly Connected TC Calc ! ~ _..- __-- r ------._ ..._ --- _ -----...._ __- - Type Description Length .Slope Coeff Misc ----- TT ~J _ _.._. _. _ _ _ _~ _. Sheet :Smooth Surfaces.: 0.011 ;16.00 ft 2.00% 0.0110 2.00 in ;0.35 min :' ;Sheet Smooth Surfaces.. 0.011 '150.00 ft 0.50% 0.0110 2.00 in 13.69 min 'J Channel (interm) 'in pipe 500.00 ft 0.~0% 0.0090. 2.08 mm ~ - - __ __..- ...---- - - --- --- __.__ - _m.. _ Directly Connected TC _ . ~_ _ __ 6.13 min _._ u Pervious CN Calc ii '~ Description SubArea € Sub cn '~ Open spaces, lawns parks (~75% grass) 0.15 ac 80.00 -~ v ,, --~ Combined 100-year/24-hour Hydrograph Details for Basins A, B & ~J Hydrograph ID: a+b+ c 100-yr '~ Area 2 5500 ac Hyd Int ;10.00 min Sase Flow ' u Peak flow ;2 191 ~ cfs Peak Tim e ;8.00 hrs Hyd Vol 0.7523 acft r, Time (hr) ,Flow (cfs) t Time (hr) ;Flow (cfs) Time (hr) ;Flow (cfs) u W X0.83 - 0.0358 8:83 0.7751 16.50 0.2988 ~ ~ 1.00 ' 0.0631 9.00 ~ 0.7764 - 16.67 0.2989 ~ _. ~'1 17 . .± 0.0958 ' ~ 9.17 0.5941 16.83 ~ 1 0.2990' `'1.33. ~ 01 162 ~ 9:33 ~ ~ 0.5840 [ 17.00 0.2991 ~ 1 50 0.1325 9.50 0.5847 17.17 0 2804 ' 1.67 0.1563 ~ 9:67 ? 0.5301 17:33 0.2793 183 0.1696 9 83 ; 05274 ~ 17.50 0.2794 , _._ . . 2.00 - 0.1803 10,00 ~ 0.5279 17.67 - 0.2794 ', '-! 2.17 ~ .: 0.2017 10.17 `~~-0.4730 ~~17.83 _ ~ 0.2795 '~ 2.33 0 2110 10.33 0.4701 18.00 0.2796 ' 2.50 0 2184 10.50 ~ 0.4705 ; 18.1.7 0.2608 ~} ~ 2 67~~ ~~; 0.2248 10.67 ` ~ 0.4338 ~ 18.33 ~ 0.2597 ~! ~ 2.83 0.2303 .10.83 i 0.4319 18.50 '. 0.2598 3.00 02350 11.00 0.4322 `18.67 0.2598 3.17 ; 0.2392 11.17 ~ 0.4139 18.83 ~ 0.2599 ~ 3 33 __ 0 2429 __ 11.33 ~ 0 4131 _.. 19.00 0.2599 3.50 ~, 0.2462 11.50 i 0.4134 Y 1917 0.2411 ~` ____ ~ 3.67 _ ~ __ 0.2640 _..__v.__ 11.67 .. _ 0 3950 _. ~. ~_ 19.33 0.2400 ~J -- 3.83 ---- 0 2677 _.:... __ _. 11.83 __ 0.3941 ~ 19.50 0.2401 v r, r, J 4.00 0.2703 12.00 0.3944 19.67 0 2401 4.17 0 3032 12.17 0.3760 19.83 0.2401 rl -- 4.33 _._... 0 3074 __ 12.33 __ 0 3750 . _ _ 20.00 _ - 0 2402 J 4.50 0.3097 12.50 0.3752 20.17 0.2402 r', 4.67 0.3430 12.67 0 3568 20.33 0.2403 ~ 4.83 ' 0.3469 12.83 - ~ ~ w 0.3558 20.50 ~~'~ _ 0 2403 ~ _ - 5.00 ' _ __..___ _ _ 0.3520 _ _ . ~ _ _ _ ~ 13.00 _ _ _ . .. 0.3560 . ._ .,_.. 20.67 ': _ ____. 0.2403 5.17 ' 0.3888 W 13.17 ~ 0.3561 20.83 0.2404 ,-, ~'~533 !03938 13.33 0.3563 21.00 0.2404 u 5.50 0.3968 13.50 0.3564 21..17 -- -- 0.2405 5 67 0.4326 13.67 0 3379 21.33 0 2405 r t _, ' . _ ~, _ .. ~. ~ _ _ _. _..... _- x5.83 ~~ . t .._.. 0.4374 - ~ 13.83 =,, ~ ~~.._ .. 0.3369 _..._ i 21:50 ~ _ _.._. ~~..,. 0.2405 6.00 0.4402 14_.00 0.3370 ' 21,67 0.2406 6 17 0 5101 ~ 14.17 0 3372 21.83 0.2406 __. _ . 6.33, ~ ~~ 0.5171 ~ 14:33 ~ ' 0.3373 r ~ 22:00: 0.2407 r! ~ 6 50 ~ !--0.5202 ', 14.50. 0.3374 22.17 _ ~..0 2218.,.._. `~ ~6 67 .~ ~ 0.6257 14.67 ~ 0.3188 2233 ~ 0.2207 '~~ ~ 6.83 --0.6352 14.83 , ! 0.3178 22.50 - ~ 0.2207 ~ ~ 7 00 • ~ ~ 0.6387 15.00 ° 0.3179 ~ 22.67 ~ 0.2207 ,~ 7.17 0.7637 15..17 0.3180 ~ 22.83 , 0.2208 ~ 7:33 = - 0.7749 ~ 15.33,, W~ 0.3181 F 23.00 ~ 0.2208 _ :7.50 ~_ ' 0.7789 . W ~ _ 15..50 _ # ~__- 0.3182 _ -,- __ 23.17 0.2208 ~ . _~:~._._.T ~_.._. . r _~~_ ._.._- _--- ___--- - '7 67 ' 2.0757 15.67 0.2996 23.33 0.2209 -_W_:. ..._ _ ._______ - _. _-.-_.-- - `7.83 2.1721 15.83 0.2985 23.50 ' 0.2209 ~ ~~ ~~~8.00 ~ ' 2.1915 16.00 ~; 0.2986 23:67 ~~ 2209 I ~0 : : . 8.17 1.1180 ~ 16.17 0.2987 ~ = 23:$3. ~ 0.2209 ~, ~ 8 33 _- 1 0579 16 33 0 2988 24.00 0 2210 . 8.50 1.0609 16 .50 0.2988 24.17 0.0117 ~ .8.67 0.7897 16.67 0 2989 2433 0.0000 ~ __ ..~. n___._..~ .___.w__..-.._._ __~_ _......,_ Licensed to: KPFF, Inc. -Olympia rl U ~1 u n rl ~~ u n u ~J LJ r , J rt U n iJ r-i ~~ v ~l rt ~J u Combined 6-month/24-hour Hydrograph Summary for Basins A, B & C Hydrograph ID: a+b+c - 6-mo Area 2.2100 ac ~Hyd Int ;10.00 min iBase Flow Peak flow 0.5984 cfs Peak Trme 8.00 hrs _ ' Hyd Vol 0.1941 acft Infiltration Pond Storage and Infiltration Modeling LPOOLCOMPUTE [pond aqu] SUMMARY using Puls Start of live storage: 340.0000 ft Event Match Q (cfs) ;Peak Q (cfs) Peak Stg (ft) Vo] (cf) ;Vol (acft) -Time to Empty;' -100 year ` 0.0000 0.4861 343.0020 ~~774.93 ~ 0.1326 24.50 Id4 year Hyaba~rahh Plut [v, s+tific 100 yr; ; 2 #u7,OO,yeap ou3 U : e ~ - ., 0 ~ _ eta, .t" = .r x, 00 ° r"-, oo - ° o ~ r~ c, v ~„ v, r~ ti ro m o _ __ o Sri ~ 00 ai o 0 0 0 ~ _ ~ N N N V N N Time rn Hcurs Running C:\\Documents and Settings\\EdM\1My Documents\lpond aqu Report.pgm on Tuesday, December 26, 2006 Summary Report of all Detention Pond Data Event :Precrp (in) '6 month 1.2800 2 year - :2.0000 - - 10 year 3.0000 100 yeaz 14.0000 HYDLIST SUMMARY [match dummy] [a+b+c 100-yr] [100 year out] LSTEND ~J n ~J Li L1 n v v u r, U ~J n u ~J Li v ~J n ~1 tJ HydID .. _ __ '..Peak Q (cfs) ;Peak T (hrs) ';,Peak Vol (ac-ft) ',.Coot Area (ac) :match dummy 0.0000 0.00 0.0000 ' 0.0000 a+b+c 100-yr - 2.1915 8.00_... --- ~~~.._~_ _..-- __. _. - 7523 2.5500 •100 year out 0.4861 6.33 ', 0.7524 ' ~ 2.5500 STORLIST [aqu] LSTEND Record Id: aqu 'Descrip: Icb Increment ''O.lO fr Start El. ;341.0000 ft Max El '.345.0000 ft Length 70 0000 ft -Width :15.0000 ft Length ss] 3.OOh:ly Length ss2 3.000Oh:ly .Width ssl i3.00hav Width ss2 3.000Oh:ly :Only consider bottom area for infiltration DISCHLIST [infiltr aqu] LSTEND Record Id: infiltr aqu Descrip: 'Prototype Structure ~~Increment 0.10 ft __. _ _..... i Start El. 341.0000 ft ,Max El. X341.0000 ft ;`Infiltration rate'20.0000 in/hr WP Multiplier ~ 1.00 Licensed to: KPFF, Inc. -Olympia Appended on: 11:39:22 Tuesday, December 26, 2006 ~, r, J -, r, r, ~-, u -, r, r, r, r, J r-, r-, v Appendix II Preliminary Drainage and TESC Plan ~y z O z z_ ~ ~ Z Z O Z O Z O = N ~ Z O U W i., ~ __ _._~,<_ _- ~~ __ x ~~. _- .wt _ - a, k - _ ~~ ~ ~ ~~ z~~~~ ~ ~n ~ ~ ¢~ r~ O ° ~s~€ ~~~~ sg~~~~ Y1 o ~°~oQ g~~~ ~ ~~~ ~b~ ~~ ~ ~ ~,~~~~o~~e ~~ mW °m~ ~~~- ~'~~ ~So~~~ ~~=~~~~~'~~ ~gi~~~~€o~~ €~~~~~ms~ ~ o ~+ I °~ ~ ~ N~W I ~ ~~~~_m~~~~~~~s~~~~~~ _ ~ m ~ ~ .~ ~~ o~ ~ ~ ~ ~ ~ ~ W a ~ ~ ~ ~ €~ ~~~ ~a~ ~ ~~ r; ~~_ ~ ~ ~~~ € ~ ego ~a ~~ ~~a~ °~~ 11111 1 y~¢ p ~ ~~~~ ~~~ ~_~ ~ yp~'~ $~ ~~ ~~°~~ ~ w a 1 ~ ~ ~ ~~~'~y~°o ~~°~ ~~ o ~~ ~~~~ ~ ~~ 'l ~~a~o_z~~ saam °~a~b ~ G~ Fo ~ ~ ~ ~ ~ O `loo~~o~,~~ t~~a~~ ~o S ~~ V ~~€~ ~q ~~6~~F~~os~~ ~ ~o O ~oo~~~~~9~B~o~Y~€~~~~° ~~~~ i ~. w a~ a'~~~ ~ ~ ~~a~~° ~~'doyk ~ ~~ ~ ~ ~~€~~ ~ Noz~ ~ ~~~ ¢ ~ ~~~ ~ ~~~ o~ ~ ~~~ D LL ~r~~~~~~~~°s~a n~~~~~~IC~~~ / Q rv ! r fN - N n] Y vi ao r m (t ~ - ~,~ -~C- - -_ -_ __ __~____ ~~ ~- 4g ., - ___ ~ °~ 0 -_ - __- -_ --- --- -_--_ dr -'-____ ; __ --- -'---- - ~ ~ F ~' e ~ ~ ~ ~ ~~~ -- ~ - -~ - i ` ~ w= N '" ~ ~ ~ w~M~ ~~~~ w~ N~ "~ ~ ~m~ ~ 3 ~~ o~ d m ~ ~~ i i Y -__~ t~ ~Fai~~~~.~ NE,i ~a8 _ ~ S ____-_~ \\i ~_-mot ~ ~a~~ ~~ ~~®~N='n "' w ~ :- ~~N a _ Y ~~ ,~/ _ ~ ~;~ K-5 P _ N m ~ iii %i i i ~ ,F' ~ ~ r ~ ~ ~ ~ '- ° ~ n ~ ~ ~ _ o B~'~~ ~ '9~ ° ~ orri°~ +~ ~ ~ s ~o ~, ~ ~ w~ ~~ ~ i~ ~ ~~~~ E ° _--, _ - __ __~_-_ - ~ ~ ~~~~ ooze ~o~ ~~~~o .w -- ~ -- x~ ° ~ w N ~ ~ o __ / A - F x t4~~= ~ ~ ~a~ {L 55~~~ ~ ~~y+J~ar~~W \ O ~ _. ___. _.___.._ -- ,u. ~~ ~ ~ I I I I ~ ~ ~ ~ ~~ ~~i ~1 ~1 ~~ ~~ ~~ ~~ ~~ u r-, r, ~i r, -, r, r, r, J r, i r, r, -~ Appendix III Facility Summary Form v v ~I U n rl n ~1 n ~J n U ~J n u U ~J ~J n n ~J n ~J THURSTON REGION FACILITY SUM1ti7ARY FORM Complete one (1) for each facility (detention/retention, coalescing plate filter, etc.) on the project site. Attach 8 1/2 x ] ]sketch showing location of facility, Proponent's Facility Name or Identifier (e.g., Pond A): See Part 6 Name of Road or Street to Access Facility: Mossman St. SE Hearings Examiner Case .Number: Development Rev. Project No./Bldg Permit No.: Parcel 1Vum ber: 2 172 44 0 1 0 0 To be completed by Utility Staff: Utility Facility Number Project Number (num) Pazcel Number Status: (num, lch) 0, Known; ], Public; 2 Unknov<m; 3, Unassigned Basin and Subbasin: (num, 6ch) (2ch for basin, 2ch for Subbasin, 2ch-future Responsible jurisdiction: (alpha, 1 ch) Part 1 -Project Name and Proponent Project Name: Terra Valley Golfand Country Club Project Owner: TVGCC LLC Project Contact: Doug Bloom Address: 4200 6Ave. #30l Lacey WA 98503 Phone: f360~9~3-9655 Project Proponent: (if different) Same Address.' Same Phone: Same Project Engineer: Mark Steepv P F Firm: KPFFCnn.cultin~F~ineanc Phone(360)2927230 r, v r, ~i 'l i rl rl 'l 11I ~J 'lI U rt i ~J iJ '~l r-l v n Part 2 -Project Location Section Township Range 24 17N Part 3 - Tvpe of Permit Application Type ofpermit (e. g., Commercial Bldg: Commercial Building Other Permits (circle) ^DOF/W HPA ^COE 404 ^COE Wetlands ^DOE Dam Safety ^FEMA ^Floodplain ^Shoreline Mgmt ^Rockery/Retaining Wa11 ^Encroachment ®Grading ^NPDES ^Other Plumbing, Electrical, Utility Other Agencies (Federal, State, Local, etc.) that h ave had or will review this Drainage Erasion Control Plan: N/A Part 4 -Proposed Protect Descri~on What stream basin is this project in (e.g., Percival, Woodland): Yelm Creek Project Size, acres 2.~5 Zoning.• - P/OS Onsite: Residential Subdivision: No Number of Lots: Lot size (average), acres: Building Permit/Commercial Plat : Yes Building(s) Footprint, acres : 0.08 Concrete Paving, acres: 1.29 Gravel Surface, acres: 0 Lattice Block Paving, acres: 0 Public Roads (including gravel shoulder), acres: 0 Private Roads (including sidewalks), acres : 0 r, r, ~II ~J r~ u n u n u n U U n LJ r, ~1 n LJ n ~1 U ~J Onsite Impervious Surface Total, acres: 1.49 Part 5 -Pre-Developed Proiect Site Chazacteristics Stream through site, y/n: No Name: DNR Type: Type of feature this facility dischazges to (i.e., lake, stream, intermittent stream, pothole, roadside ditch, sheetflow to adjacent private property, etc.): Infiltration to ,groundwater Swales, Ravines, y/n: No Steep slopes, (steeper than I5%) y/n: No Erosion hazard, y/n: No IOOyr. Floodplain, y/n: No Lakes or Wetlands, y/n: No Seeps/Springs, y/n: No High Groundwater Table, y/n: No Wellhead Protection or Aquifer Sensitive Area, y/n: Yes Part 6 -Facility Description -Infiltration Pnnd To[al Area Tributary to Facility Including Offsite (acres): 2.55 Total Onsite Area Tributary to Facility (acres): 1.73 Design Impervious Area Tributary to Facility (acres): 2.21 Design Landscaped Area Tributary to Facility (acres): 0.34 Design Total Tributary Area to Facility (acres): 2.55 Enter a one (I) for the type offacility.• Wet pond detention Wet pond water surface area, acres Dry pond detention 1 Underground detention Infiltration pond 1 Dry well infiltration Coalescing plate separator u r, ~ Centrifuge separator Other: Outlet type (Enter a one (I) for each type present) `~ Filter 7 ~ Oi! water separator r ? Single orifice '~ Multiple orifices r, Weir Ll Spillway ~ Pump(s) Other -Infiltration I r, Part 7 -Release to Groundwater Design Percolation Rate to Groundwater (ifapplicabZe) 20 inches/hour n ~J ,~ v U LJ ~l ,~ J Appendix IV FEMA Firm Map -~ -, r, ~i u u ~J u ~J ~J r-, ~1 ~1 n u n v r, .J J r, r, -~ r, ~, u u r, ~~ u u r, Appendix V Vicinity Map r, u -,- ,~. ~~~ ~~~ r, t ~1~° z ~- ~ ~,.. ~~~ v~' !.: ~..` ~i` rl 15 _~ .` t;. .. r~.~f. ~~ G~w Y , .A ~~ U ~~ ~f~ n "..~qti. ~~R r,~.F yt~ -gym , LI ~~. ~f~_..: '~r.. ~~~~~ ~~~n - A r1 U n `~ U ~~~/ Sid /~ n { F fi}..., U vll x31 . n f ~~yJ `~ } - r, ~I L~ n LJ LJ L~ .~~° . _-~ Z- r`Yc. _k'L ~a .. `~ _ ~! ~~ l ~A~ '+'~C. V ~~ ~~ _ 3rd_~1 Jr. sn G ~? .~@1. tl y i 1 s .j i~ y 3 i'. G of T d }~( ~ 4; 1.~1i13 a~aj3~r C~ C f~ _U ~~` ',~,,.. l i' >Cry ;~T o t '.- ~I7 .:Q ~~~` 4~ c r-„ r, r, -~ r, ~, r, r, r, r, r, ~J r, ~, T-, r, r, Appendix VI Aqua-Swirl Application Literature r, u Introduction r~ ~~~5'~e6n ~per~tBLp6'9 '-' -; Retrofit Applications !P Irostallatitsn ~, ;~: Buoyancy Tra$I'iC LOaf~ICi~ ~ Inspection and I~ainteftan~e 'J ate Agua-Site Nlorks~e~et ~, Asiua-Swirl T"' Sizing Chart ,~ =~ Aelua- swirl TM Sample detail r, Ac{ua-Swirl TM Specifoeatiors 5 ~_J ,- , u r, u u r} r, J r, ~i r-, LJ n -, v r, LJ -~ _J -, J -, ~~ w~~ Aqua-SwirlT'" Concentrator Stormwater Treatment Systems ine patented Hqua-swm~~~~ concer provides a highly effective means for removal of sediment, floating debris and free-oil. Swirl technology, or vortex separation, is a proven form of treatment utilized in the Stormwater industry to accelerate gravitational separation. Independent university laboratory performance evaluations have shown the Aqua-SwirlTM achieves a TSS (Total Suspended Solids) removal 01 91% calculated on a net annual basis. See the 'Performance and Testing Section for more detai/s. Each Aqua-SwirlrM is constructed of High- Density Polyethylene (HDPE), and is therefore modular, lightweight and durable, eliminating the need for heavy lifting equipment during installation. Inspection and maintenance are made easy, with oversized risers that allow for both examination and cleanout without entering the chamber. ~- System ®peration The Aqua-Swir/"" Concentrator Conveyance F/ow Diversion System provides full treatment for the most contaminated "first flush," while the cleaner peak storm flow is diverted and channeled through the main conveyance pipe. Many regulatory agencies are establishing "water quality treatment flow rates" for their areas based on the initial movement of pollutants into the storm drainage system. n U u n ~1 v r, ~1 U n r-, ~J ~l ~J ~1 v ;~ The operation begins when stormwater enters the Aqua- SwirlT"' through a tangential inlet pipe which produces a circular (or vortex) flow pattern that causes contaminates to settle. Because stormwater flow is intermittent by nature, the Aqua- SwirlT"' Concentrator retains water between storm events providing both "dynamic and quiescent" settling of inorganic solids. The dynamic settling occurs during each storm .event, WI111e the quiescent settling takes Floatable debris in the Aqua-Swirl•^ Concentrator place between successive storms. A combination of gravitational and hydrodynamic drag forces encourages the solids to drop out of the flow and migrate to the center of the chamber where velocities are the lowest, as shown from extensive CFD modeling, see "Performance and Testing" for more details. A large percentage of settleable solids in stormwater are reported to be small and have low settling velocities. Therefore, the volume of water retained in ~-; the Aqua- ., SwirlT"' Concentrator OUt(et provides the "="`~ ` - quiescent settling that increases performance. Furthermore, due to finer sediment adhering onto larger particles (less than 200 `? microns), these larger particles c settle rather than stay = suspended in the water. Tnle~ 3 ~J ~.I _~. __~. _~, ~, ~7c~1-i,. r, 'J The treated flow exits the Aqua-SwirITM Concentrator behind the arched outer ,~ baffle. The top of the baffle is sealed across the treatment channel, thereby eliminating any possibility of floatable pollutants to escape the system. A vent pipe is extended up the riser to expose the backside of the baffle to atmospheric conditions, preventing a siphon from forming at the bottom of the baffle. ~ As recommended by the Center for Watershed Protection and some r, municipalities, the Aqua-SwirlT^^ can also operate in an offline configuration providing full treatment of the "first flush"; however this orientation will require the installation of additional manhole structures for diverging the flow to the Aqua-SwirlT^^ for treatment and converging back to the existing main conveyance storm drainage system. `~ a Custom Aoolications ,J The Aqua-SwirITM Concentrator system can be modified to fit a `~ variety of applications in the u field. The angles for inlet and outlet lines can be modified to '~ fit most applications. The photo J on the left demonstrates the r flexibility of Aqua-SwirITM ' installations. Two Aqua-SwirITM ~ units were placed side. by side in order to treat ahigh-volume ~ of water while occupying a -~ small amount of space. This ~ Custom designed AS-9 Twin, Aqua-Swirl'" Concentrators configuration IS an example Of the many ways AquaShieldTM J can use HDPE products to adapt to a variety of applications. r, Retrofit Aaolications ~ The Aqua-SwirITM Concentrator system is designed so that it can easily be used ~ for retrofit applications. With the invert of the inlet and outlet pipe at the same elevation, the Aqua-SwirITM can easily be connected directly to the existing storm conveyance drainage system. Furthermore, because of the lightweight nature ~ and small footprint of the Aqua-Swirl'M, existing infrastructure utilities (i.e., J wires, poles, trees) will be unaffected by installation. ~~ ~ 4 J n r1 r-, J ~~ rJ n ~J n L1 ~~ ~S u r, u L1 ,R w~:..~ ~~c~r ~t~r , 4.ti~« ..~ - Installati®n The Aqua-Swirl"' system has been designed and fabricated as a modular unit with no moving parts or assembly required on site. This facilitates an easy installation of the system. r------ Since all of AquaShieldT"' systems are fabricated ~- ., from HDPE, the Aqua-SwirlrM is lightweight, and can ~ be installed without the use of heavy lifting ,'.~'i ; ~ _, equipment. Lifting supports or cables are provided ~~-Y~--~~'t to allow easy offloading and installation with a backhoe. Compared to concrete systems, using an ~~ ~ ~ ~~, - Aqua-SwirlT^' can significantly reduce installation ~ '~ ~' ~~ costs. ~ ~`'-° -_ 5 •~.~ ~ In addition, manufactured stub-outs for the inlet ~ ,,,,; and outlet are provided. This allows the contractor ~'~ to simply attach the Aqua-SwirlT"' directly to the 'M main conveyance storm pipe with rubber couplings Typically, an AquaShield~"' representative is present - ~ ~ ~ ~~ ~~ on-site to assist in the installation rOC2ss. TheAqua-Swirl'^Concentrator p installed using a backhoe Buoyancy All Aqua-SwirlT"' Concentrator systems are supplied with an octagonal base plate, which extends a minimum of 6" beyond the outside diameter of the swirl chamber. The function of the extension on this base plate is to provide additional surface area to counter any buoyant force exerted on the system. The forces created on the base plate by the weight of the surrounding fill material offsets the buoyant force generated within the system. If needed, concrete can be poured directly onto the base plate to provide additional resistive force. AquaShield~"' engineering staff can provide buoyancy calculations for your site- specific conditions. 5 ~~ r, ~1 ~l n u r, ~J r, v n U ~, n u ~i ~, ~1 r, ,~ v ~J When installed in traffic areas, the system will be designed to withstand H2O loading. In order to accomplish this, a reinforced concrete pad shall be poured in place above the system. See the "Installation and Fabrication" section for sample concrete pad details and further details on installation and the use of HDPE. Concentrator from impact loading -~ Inspection and Maintenance Inspection and cleanout of the Aqua-Swirl'"' is simple. The chamber can be inspected and maintained completely from the surface. Free-floating oil and floatable debris can be directly observed and removed through the provided service access. cleanout of accumulated sediment will need to be performed when the usable sediment storage volume has been occupied. The depth of sediment can easily be determined using a stadia rod or tape to measure the top of the sediment pile and calculate the distance to the - water's surface. A vacuum truck can be used to remove the accumulated sediment and debris. Disposal of the material is typically treated in the same manner as catch basin cleanouts. AquaShield'"' recommends that all materials removed be handled and disposed of in accordance with local and state requirements. For further details on inspection and cleanout procedures, please see the "Maintenance" seCtlOn. Vacuum truck cleans the Aqua-Swirl'^ concentrator 6 Traffic Loading r, r, r, ,J u n u ~1 v n v v u~ ._~~ ~.~:x~...,.~.__I ,~ .__,, _ . _ _._ =~ . Alma-SwIrIT'" Sizing ~~art lEna/ish) Swirl Maximum Water Oil/Debris Sediment Aqua-Swirl'"" Chamber Stub-Out Pipe Quality Storage Storage Model Diameter Outer Treatment Capacity Capacity Diameter Flow ft. in. cfs al ft3 =rOri(Orfl a ~.'~CFO _~:q AS-2 2.50 8 12 1.1 37 10 AS-3 3.25 10 16 1.8 110 20 AS-4 4.25 12 18 3.2 190 32 AS-5 5.00 12 24 4.4 270 45 AS-6 6.00 14 30 6.3 390 65 AS-7 7.00 16 36 8.6 540 90 AS-8 8.00 18 42 11.2 710 115 AS-9 9.00 20 48 ~ 14.2 910 145 AS-10 10.0 22 54 17.5 1130 180 AS-12 12.0 24 48 25.2 1698 270 AS-XX* Custom -- -- >26 -- -- Higher wa[er quality [rea[menf flow rates cart be tlesignetl wi[h mul[iple swirls. ~ 1) The Aqua-Swir/r"' Conveyance F/ow Diversion (CFDJ prol id s f_~// t~A=tme^t J of the "first flush, " while the peak design storm is diverted and channe/ed through the main conveyance pipe. P/ease refer to your /oca/ representative for ~I more information. v 2) Many regu~atory agencies are estab/fishing "water qua/ity treatment f/r7w rates" ,~ far their areas based on the initial movement of po//utants into the storm ~ drainage system. The treatment flow rate of the Aqua-Swirfr'" system is ~ engineered to meet or exceed the /oca/ water qua/ity treatment criteria This "water qua/ity treatment flow rate" typica//y represents approximate/y 90% to 95% of the total annual runoff volume. v The design and orientation of the Aqua-Swirl'" generally entails some degree of customization. For assistance in design and specifc sizing using historical rainfall data, please refer to an AquaShieldT"' n representative or visit our website at www.AquaShieldInc.com. CAD details and specifications are available upon request. u S u r, ~i ~J ~J u n J u r1 v J ~r.,~; „r o ~~,_, ~„ ~.~._..,_, `: A®ua~~wfirlT'" S~za~ca Chart (Metric? Aqua-Swirl•"' Model Swirl Chamber Diameter mm Maximum Stub-Out Pipe Outer Diameter mm. Water Quality Treatment Flow L/s Oil/Debris Storage Capacity L Sediment Storage Capacity m3 ~''Ori/Oftl ne', ;CFO r AS-2 762 203 305 31 140 0.3 AS-3 991 254 406 52 416 0.6 AS-4 1295 305 457 90 719 0.9 AS-5 1524 305 610 124 1022 1.3 AS-6 1829 356 762 179 1476 1.8 AS-7 2134 406 914 243 2044 2.6 AS-8 2438 457 1067 317 2687 3.3 AS-9 2743 508 1219 402 3444 4.1 AS-10 3048 559 1372 496 4277 5.1 AS-12 3658 610 1219 714 6427 7.7 AS-XX* Custom -- -- >720 -- -- Higher water quality [reatment flow rates can be designed with multiple swirls. rl U 1) T,he .4q::a-3':rirl'"' .^.anveya~ca F.'cv' 6irrer ion (CFi'3j provides fuii treatment of the "first flush, " whi/e the peak design storm is diverted and channe%d through the ~ main conveyance pipe. P/ease refer to your /oca/ representative far more information. ~J 2) Many regu/atory agencies are estab/fishing 'water qua/ity treatment t7ow rates" far ~ their areas based on the initial movement of po//utants into the storm drainage uj system. The treatment Aow rate of the Aqua-Swir/r"'system is engineered to meet or exceed the /oca/ water qua/ity treatment criteria. This "water qua/ity treatment ~ flaw rate" typica//y represents approximate/y 90% to 95% of the iota/ annual runoff volume. `~ The design and orientation of the Aqua-Swirl'" generally entails some degree of customization. For assistance in design and specific sizing using historical rainfall data, please refer to an AquaShieldT"' ~~ representative or visit our website at www.AquaShieldInc.com. CAD details and specifications are available upon request. :J 9 r, n J ~i r, u v ~J r, u J rl -~ u u r-, ~J ~i ~J ® Aqua-SwirlT'" Sample Detail Drawings Sample Aqua-Swirl~"^ detail drawings are provided as examples of the type of systems that AquaShield'"' can offer for a specific work site. ~ ~., 10 ----- - ~~ ~, J ~J ~J u ~J v J ~J u u -S ~S .J u ~~ ~J r, r, r-, r, r, ,~ r, u ~~ ~i r-, r, ~~ ~~ u U ~~ .~ ~ ~.<<~. ,t,~~_ _~.._._ __._ Aqua-SwirITM Specifications GENERAL This specification shall govern the performance, materials and fabrication of the Stormwater Treatment System. SCOPE OF WORK The Aqua-Swirl~^^ Concentrator shall be provided by AquaShieldT"', Inc. 2733 Kanasita Drive, Chattanooga, TN (423-870-8888) and shall adhere to the following material and performance specifications at the specified design flows, and storage capacities. MATERIALS A. Stormwater Treatment System shall be made from high-density polyethylene (HDPE) resins meeting the following requirements: 1) HDPE Material -The HDPE material supplied under this specification shall be high density, high molecular weight as supplied by manufacturer. The HDPE material shall conform to ASTM 03350-02 with minimum cell classification values of 345464C. 2) PHYSICAL PROPERTIES OF HDPE COMPOUND a) Density -the density shall be no less than 0.955 g/cm3 as referenced in ASTM D 1505. b) Melt Index -the melt index shall be no greater than 0.15 g/10 minutes when tested in accordance with ASTM D 1238- Condition 190/2.16. c) Flex Modulus -flexural modulus shall be 110,000 to less than 160,000 psi as referenced in ASTM D 790. d) Tensile Strength at Yield -tensile strength shall be 3,000 to less than 3,500 psi as referenced in ASTM D 638. e) Slow Crack Growth Resistance shall be greater than 100 hours (PENT Test) as referenced in ASTM F 1473 or greater than 5000 hours (ESCR) as referenced in ASTM D 1693 (condition C). 11 -, ~ n _ v f) Hydrostatic Design Basis shall be 1,600 psi at 23 degrees ~ C when tested in accordance with ASTM D 2837. ~ g) Color -black with minimum 2% carbon black. B. REJECTION -The Stormwater Treatment System may be rejected for failure to meet any of the requirements of this specification. ,~ ~ERFORM~lNCE `J A. The Stormwater Treatment System shall include a _-inch inner --~ diameter (ID) circular hydrodynamic flow-through treatment ~ chamber to treat the incoming water. A tangential inlet shall be provided to induce a swirling flow pattern that will cause r-, sedimentary solids to accumulate in the bottom center of the ~ chamber in such a way as to prevent re-suspension of captured particles. An arched baffle wall shall be provided in such a way as to prevent floatable liquid oils and solids from exiting the treatment ~ chamber while enhancing the swirling action of the Stormwater. ~~ B. The Stormwater Treatment System shall have a sediment storage ~, capacity of -cubic feet and be capable of capturing _ gallons of petroleum hydrocarbons. The Stormwater Treatment System `~ shall have a treatment capacity of cubic feet per second J (cfs). The Stormwater Treatment System shall be capable of removing floating trash and debris, floatable oils and 80% of total `~ suspended solids from Stormwater entering the treatment chamber. C. Service access to the Stormwater Treatment System shall be r' provided via 30-inch inner diameter (ID) access riser(s) over the treatment chamber such that no confined space entry is required to perform routine inspection and maintenance functions. TRE~OTPMENT CH/LTRBER CONSTRUCTION A. The treatment chamber shall be constructed from solid wall high- density polyethylene (HDPE) ASTM F 714 cell class 345464C. For sizes above 63-inch OD, the treatment chamber shall be ,~ constructed from profile wall HDPE ASTM F 894 RSC 250 pipe or `-~ solid wall HDPE. B. The bottom thickness of the treatment chamber will be determined `'~ in accordance with ASTM F 1759. Calculations must be provided to ~~ justify the thickness of the bottom. u ~J 12 r, ~J r, r, ~ c. ~, n ~J ~r ~~,~ ~ ~w,. _._~ ~ ter, : ~a~,_..._ The inlets and outlets shall be extrusion welded on the inside and outside of the structure using accepted welding practice. D. The arched baffle wall shall be constructed from HDPE and shall be extrusion welded to the interior of the treatment chamber using accepted welding methods with connections made at 180 degrees of each end. r, E. HDPE lifting supports may be provided on the exterior of the 'J Stormwater Treatment System in such a way as to allow the prevention of undue stress to critical components of the Stormwater Treatment System during loading, off-loading and moving operations. The lifting supports shall be constructed as an ,-, integral part of the treatment chamber and extrusion welded using ~ accepted welding practices. r, F. Top of the treatment chamber shall be built to the requirements of the drawings. Deep burial applications shall require a reinforced HDPE top. r, ~, Reinforced concrete pads spanning the treatment chamber will be required with traffic rated frames and covers when the Stormwater r, Treatment System is used in traffic areas. A professional engineer shall approve the design of the concrete pad and the calculations must be included in the submittal. r, ~i The manufacturer upon request can supply anti-flotation/ buoyancy calculations. In addition, typical drawings of the AquaShield r' Stormwater Treatment System with concrete anti-flotation ~~ structures can also be provided. Anti-flotation structure design and approval are ultimately the responsibility of the specifying engineer. ~' The contractor shall provide the anti-flotation structures. u ENSTALLATEON n u A. Excavation and Bedding The trench and trench bottom shall be constructed in accordance r' with ASTM D 2321, Section 6, Trench Excavation, and Section 7, J Installation. The HDPE Stormwater Treatment System shall be installed on a stable base consisting of 12 inches of Class I stone ~, materials (angular, crushed stone or rock, crushed gravel; large ~-~ void content, containing little or no fines) as defined by ASTM D r, 2321, Section 5, Materials, and compacted to 95% proctor density. ~J 13 n ~J r, " ~ u All required safety precautions for Stormwater Treatment System r~ installation are the responsibility of the Contractor. ~. B. Backfill Requirements Backfill materials shall be Class I or II stone materials (well graded `~ gravels, gravelly sands; containing little or no fines) as defined by ASTM D 2321, Section 5, Materials and compacted to 90% proctor density. Class I materials are preferred. Backfill and bedding ^' materials shall be free of debris. Backfilling shall conform to ASTM u F 1759, Section 4.2, ~~Design Assumptions". Backfill shall extend at least 3.5 feet beyond the edge of the Swirl Concentrator for the full ~ height to sub grade and extend laterally into undisturbed soils, C. Pipe Couplings Pipe couplings to and from the Stormwater Treatment System shall u be Fernco®, Mission'"' or equal type flexible boot with stainless steel tension bands. A metal sheer guard shall be used to protect the flexible boot. v ,~ DIVISION OF RESPONSIBILITY ~-1 A. Stormwater Treatment System Manufacturer The Manufacturer shall be responsible for delivering the ~ Stormwater Treatment System to the site. The system includes the ~ treatment chamber with debris baffle, inlet and outlet stub-outs, lifting supports, 30-inch ID service access riser(s) to grade with temporary cover, and manhole frame(s) and cover(s). ~~ B. Contractor The Contractor shall be responsible for preparing the site for the ~ system installation including, but not limited to, temporary shoring, , excavation, cutting and removing pipe, new pipe, bedding, and ~ I compaction. The Contrac*_or shall be responsible fer furnishi~ g the `-f means to lift the system components off the delivery trucks. The ,~ Contractor shall be responsible for providing any concrete anti- floatation/anti-creep restraints, anchors, collars, etc. with any straps or connection devices required. The Contractor shall be ,~ responsible for field cutting, if necessary, HDPE service access risers to grade. The Contractor shall be responsible for sealing the pipe connections to the Stormwater Treatment System, backfilling ~ i and furnishing all labor, tools, and materials needed. u ~~ i4 .-, 1 11 u SUBMITTALS `~ The Contractor shall be provided with dimensional drawings and, when ~J specified, utilize these drawings as the basis for preparation of shop drawings showing details for construction and reinforcing. Shop drawings `~' shall be annotated to indicate all materials to be used and all applicable ~ standards for materials, required tests of materials and design assumptions for structural analysis. Shop drawings shall be prepared at a ~ scale of not less than '/a inch per foot. Three (3) hard copies of said shop ~ i drawings shall be submitted to the Specifying Engineer for review and ,~ approval. `~ QUALITY CONTROL INSPECTION A. Materials ~ The quality of materials, the process of manufacture, and the finished sections shall be subject to inspection by the Specifying ,~ Engineer. Such inspection may be made at the place of ~~ manufacture or on the work site after delive ry, or at both places. ,~ The sections shall be subject to rejection at any time if material ' conditions fail to meet any of the specification requirements, even `-' though sample sections may have been accepted as satisfactory at ,~ the place of manufacture. Sections rejected after delivery to the site shall be marked for identification and shall be removed from U the site at once. All sections, which are damaged beyond repair ~-, after delivery will be rejected and, if already installed, shall be repaired to the Specifying Engineer's acceptance level, if permitted, - or removed and replaced, entirely at the Contractor's expense. r , B. Inspection All sections shall be inspected for general appearance, dimensions, ~ I soundness, etc. ~ C. Defects ~ Structural defects may be repaired, subject to the acceptance of the Specifying Engineer, after demonstration by the manufacturer `~ that strong and permanent repairs will be made. The Specifying ,~ Engineer before final acceptance of the components shall carefully inspect repairs. r~ ~J ~~ 15 v r, .~ ~-, v r, J ~i -, r, ~i U r, u r, v ~J ~J ~~ a ~i Appendix VII Maintenance Agreement AGREEMENT TO MAINTAIN ~ STORMWATER FACILITIES BY AND BETWEEN `-! TVGCC LLC ~ ITS HEIRS, SUCCESSORS, OR ASSIGNS (HEREINAFTER "OWNER") aJ AND THE CITY OF YELM `-' (HEREINAFTER "JURISDICTION") The upkeep and maintenance of stormwater facilities is essential to the protection of r{ water resources. All property owners are expected to conduct business in a manner ~j that promotes environmental protection. This Agreement contains specific provisions with respect to maintenance of on site stormwater facilities. ~~ LEGAL DESCRIPTION: 24-17-1E 2.50A SE SE COM X E LN WITH S LAT OF CANAL WLY ON CANAL4 Whereas, OWNER has constructed improvements, including but not limited to, homes, ~ 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 OWNER hereby enter into this Agreement. The ~ responsibilities of each party to this Agreement are identified below: ~' u OWNER SHALL: (1) Implement the stormwater facility maintenance program included herein as Attachment ,-, .,A„ u THE JURISDICTION SHALL: n (1) Provide technical assistance to OWNER in support of its operation and maintenance activities conducted pursuant to its maintenance program. Said assistance shall be ,-~ provided upon request and as City time and resources permit, at no charge to OWNER. (2) Conduct a minimum of one (1) site visit per year to discuss pertormance and problems with OWNER. ~J (3) Review this agreement with OWNER and modify it as necessary at least once every `~ iJ three (3) years. n REM EDIES: ,~ (1) if the JURISDICTION determines that maintenance or repair work is required to be done to the stormwater facility existing on the OWNER 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 n i r, , ~' 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 ~ OWNER bill if required maintenance is not performed. zJ (2) If at any time the JURISDICTION determines that the existing system creates any r, 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, shat{ be required under such circumstances. All other OWNER responsibilities remain in effect. ~ (3) The owner grants unrestricted authority to the JURISDICTION for access to any and all '~ stormwater system features for the purpose of performing maintehance or repair as may become necessary urider Remedies (1) and/or (2). u (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 90 days of the receipt of the invoice for 1 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 ~j reimbursements. n This Agreement is intended to protect the value and desirability of the real property U 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 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. ~S Owner ~, ~i ~i i1 n ~~ r, u n ~1 n U n r, ~i v v ±1 t~ r, ~i STATE OF WASHINGTON ) ss. COUNTY OFTHURSTON ) On the `day of 200_, personally appeared before me, known to be the individuals} described, and who executed the foregoing instrument and acknowledge that he/she signed the same as his/her free and voluntary act and deed for the uses and purposes therein mentioned. Given under my hand and official seal this day of , 200 Notary Public in and for the State of Washington, residing at My commission expires City of Yelm STATE OF WASHINGTON ) ss. COUNTY OF THURSTON ) On the day of , 200_, personally appeared before me, who executed the foregoing instrument and acknowledge 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 official seal this day of , 200_ Notary Public in and for the State of Washington, residing at My commission expires u