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20180242 Prelim Stormwater ReportYELM AUTO RECYCLING PRELIMINARY DRAINAGE REPORT JUNE 2018 MEngineering DESIGN -) PERMIT -> MANAGE ,. Table of Contents Part 1— Project Site Analysis and Data Part 2— Site Development Layout Part 3 — Offsite Analysis Report Part 4— Applicable Minimum Requirements Part 5 — Permanent Stormwater Control Plan Part 6 — Source Control BMPs Part 7— Construction SWPPP Part 8—Special Reports and Studies Part 9—Other Permits Part 30—Operational and Maintenance Plan Part 11— Bond Quantities and Financial Responsibility Part 12 — Grading and Drainage Plans Project Engineer Prepared by: RB Engineering, Inc. (RBE) _ PO Box 923 Chehalis, WA 98532 (360)740-8919 Ro be rtb (D RB E n o i n e e rs. co m Contact: Robert W. Balmelli PE RBE Project: 17041 Prepared for: NPR Holdings LLC Ubaida Mufrej 3655 E. Marginal Ways Seattle, Washington 98134 u baida(a),safariexoorts. co m ' Reference: 2014 WSDOE Stormwater Manual Project Engineers Certification "I hereby certify that this Drainage and Erosion Control Plan for Yelm Auto Recycling has been prepared by me or under my supervision and meets minimum standards the Stormwater Management Manual for Western Washington and normal standards of engineering practice. .. I hereby acknowledge and agree that the jurisdiction does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities designed by me." Drainage Report PART 1 — PROJECT SITE ANALYSIS AND DATA Permit Requested: Site Plan Review Other Permits Required: Building Permit Grading/Earthwork SEPA Review Agency Permit No.: Pending Site Address: 939 North Pacific Rd Yelm, Washington 98597 Section, Township, Range: Section 19 Township 17 Range 02E, W.M Total Site Area: 13.93 Acres Zoning: I - Industrial Project Overall Description The project is to include the development of an auto wrecking yard named, Yelm Auto Recycling, on lot 64300900200. Development will include the construction of 3 structures to be used for office space, storage and general shop/maintenance space. Construction will also include the development of onsite customer parking, graveled and paved vehicle storage yards, water, sewer, and power service, stormwater facilities, and frontage improvements along North Pacific Road. Proposed Flow Control Improvements The flow control facilities proposed for this project were designed and modeled using the latest edition of the Western Washington Hydrology Manual Continuous Simulation Program. The site will utilize the areas extremely well -draining soils to dispose of stormwater through infiltration. Stormwater will be conveyed to bioretention swales along the sites east/west boundaries. Test pits dug at the stormwater facilities proposed locations revealed infiltration rates in excess of 100 in/hr. For design purposed, stormwater facilities were modeled with a Ksat safety factor of 4 and an infiltration rate of 20. The soils report can be found in Part 8 of this document. Proposed Water Quality Improvements The water quality improvements for the project site runoff consist of the addition of a bioretention swales at the sites east/west boundaries. The swales will be constructed in include an 18 -inch thick layer of WSDOE approved amended soils. Proposed Conveyance System The proposed conveyance systems will consist of Type I catch basins and conveyance pipe in various sizes to distribute stormwater to the proposed stormwater facilities. Proposed Discharge Location The project site will infiltrate all runoff at the proposed bioretention swale locations. 18025 Drainage Report 1-2 Downstream Condition The site contains a ridge running SE to NW. The ridge effectively splits the site with stormwater naturally draining to the east/west boundaries. The proposed improvements will have no effect .. on the existing conditions as runoff will be contained on-site. Given the sites native well - draining soils it is likely that stormwater presently is infiltrated before leaving the site. Onsite Soils and Geology An on-site soils report was completed for this project site be Parnell Engineering, LLC. A copy of the report is included in Part 8 — Special Reports and Studies, of this document. The report stated that infiltration on-site is feasible with calculated infiltration rates exceeding 100 in/hr. The report recommends a design infiltration of 20 in/hr be used. Based upon this information the storm design concept of infiltration was selected. Drainage Report 1-3 PART 2 — SITE DEVELOPMENT LAYOUT Project Topography The site topography is nearly level to gently sloping. Elevations range from a high of 338 ft. at the south-central portion of the site to a low of 328 ft. at the NE corner of the site. Land Use and Ground Cover Site vegetation consists of sparsely located conifer trees along with Scotts bloom, indigenous brush and field grass. The subject site is bounded by rural residential property to the north, undeveloped property to the east, Northern Pacific Road NW to the south, and a private drive- way to the west. Natural or Man -Made Drainage Patterns The site contains a ridge running SE to NW. The ridge effectively splits the site with stormwater naturally draining to the east/west boundaries. The proposed improvements will have no effect on the existing conditions as runoff will be contained on-site. Given the sites native well - draining soils it is likely that stormwater presently is infiltrated before leaving the site. Tributary and Discharge Points of Flow There are no tributary points of flow. The centralized ridge on-site prevents off-site flows from entering the project. Historical Drainage Problems RBE is not aware of any historical drainage problems for this site. Existing Utilities (Storm, Sewer, Water) The existing utilities available to site include power, water, sewer, storm. Erosion Potential The site has a slight erosion potential. As part of the development plans a detailed Erosion Control Plan and Storm Water Pollution Prevention Plan will be prepared and submitted with the final drainage report for use during site construction to minimize erosion and mitigate sedimentation within and off the site. Critical Areas Onsite The site does not contain any critical areas Existing Fuel Storage Tanks Review of the onsite parcels resulted in no evidence of existing fuel storage tanks above or below ground for this property. Groundwater Wells The property does not include any onsite ground water wells. 18025 Drainage Report 2-1 Septic Systems There are no septic systems on-site. Aquifer Recharge Area The site is within the City of Yelm Aquifer Recharge Area. Wellhead Protection Area The site is not within any wellhead protection areas for public utilities. 18025 Drainage Report 2-2 PART 3 — OFFSITE ANALYSIS REPORT RBE staff visually inspected the site and offsite surrounding areas. With all runoff being infiltrated an offsite analysis was deemed unnecessary. 18025 Drainage Report 3-1 PART 4 —APPLICABLE MINIMUM REQUIREMENTS The minimum requirements for stormwater development and redevelopment sites are listed in Volume I of the 2012 SMMWW. Not all minimum requirements of this section apply to all projects. Determination of applicable minimum requirements is also based in part on Section 2.4 of the Manual. 61xrt Here 1 Applicable Criteria Areas Existing Site Impervious Coverage 0.00 AC New Plus Replaced Impervious Surface 12.44 AC Vegetation Area Converted to Lawn or Landscaped Area 0.75 AC .. Land Disturbing Area 13.19 AC 61xrt Here 1 See Redevelopment Does the sire hate 35% mmom of Tae M*.mum eusfing impen'iatss o Regwremmts avd em¢e? Flow Chmt No Does the pmjec[convezt (Fl.'3) eof Doea the projem eeemnov to I.. or result m 5,00 landscaped areas. or sgtare feet, or Noc vert 25 acres a more Beater. ofnew Plw af narice vegetationm replacedhazd pa;twe? surface Does the prajert Tea Yea No recnit in 000 sgtare feet, vv greater. of ptus replaced All `t' :.. wd swface area^ I. apple Rett the .m m [he e. and replaced hard surfaces and mntimed Yea No cegetatiov Minivmm Regtwemevts Does the project hace =1 through #1 apply to land disnubivs the new and replaced amiuities of ].000 hard cur£acee and the Yea sgtare ft ai Bream? laud diswt i. No hfininaum Require mt �� applies Fignre 2,4.1— Flow Chart for DO—i—, Requi mems b1 llew 1)11e to pment 18025 Drainage Report 4-1 Doe:rhevmjec ;ul,' 000rqune tet --- ofue d hardsmfeee areal OR Doer b.1 -odd --CODs_ 1t .In 1, 000 zouve feet or geatet Yes No Maim— Regmaeuwub Al through' -5 applJ ro \Lmumm Regovemeur, a'_aPPtie;. the new sod replaced hmd zvdaez and me land di Imbed Nen question Or,- rhe projsr, add 5 000 ogaam teras moa of uea hmd cutfa..sl OR c—h !: acre. or more cf-se ne-to Uav ar lazd:caped oma;' OR Con:en'_ `. zcre: or vtaa oF.—s segMznou to P,;Cua' Yes No Nex ,111 Rfmwum Regmtemear; :pPly to the 0nsa-ien Is deamad oeu hsd :ue(acee and the coorermd eared project' Tes N< Daea fhe project add OGG squzrt fret or more a fnea'and zwfrcect Yes No De eea hard;ut —c dd iM. or I; ma total of new vda= v!aced haM;utfxces ore to the exu hard aurfama 5.000 -quare feetmmore. eliD doe; fle aha .,h. tLe Prol mT olol.? of the P, O,oe ed otiro'.'emenY-mcludmg nm un,n-ltrcnty--..ed 50'. of the No Tes a"'-s-edr�e(artepta<em�nalue)o[the ext vogn _ emu.L_ Va adNI: ae9uu \ Yes Nordd,,. a evt ?.11 \fwimum Rryuvem ec ;,PPI to rhe uew and rtp6cedhardwface:acdm emd-'auto. mea;. Figure 1,4.2 - Flow Chart tat DetertnlNn9 Ra,ttirerrer is I., Retleeelopmenl 18025 Drainage Report 4-2 Based on the thresholds given in Figures 2.4.1 and/or 2.4.2 of Volume I of the Manual, the proposed project must address or comment on Minimum Requirements #1 through #g. These requirements as they apply to the project are discussed in more detail below. Minimum Requirement (MR) #1 — Stormwater Site Plans: All projects meeting the thresholds of Section 2.4 of Volume I of the SMMWW shall prepare a Stormwater Site Plan for local government review. The proposed project will create over 5,000 square feet of impervious surfacing, and therefore a Stormwater Site Plan complying with minimum requirements #1 through #10 is required. MR #2 — Construction Storm Water Pollution Prevention Plan: The proposed project exceeds the thresholds of Section 2.5 and therefore a Construction Storm Water Pollution Prevention Plan is required for this project. A SWPPP will be created as a .. standalone document for this project and submitted with the final drainage report. MR #3 — Source Control of Pollution: All known, available and reasonable source control BMPs shall be applied to the project to limit pollutants coming in contact with stormwater. The BMPs for this project will be incorporated into the projects Final Operation and Maintenance Plan. MR #4 — Preservation of Natural Drainage Systems/Outfalls: Proposed stormwater will be infiltrated on-site. There will be no effect to the sites natural drainage. 18025 Drainage Report 4-3 MR #5 — On -Site Stormwater Management: The stormwater management plan was developed to meet the following project threshold, "New Development Inside the UGA on a Parcel of 5 Acres or Larger". Projects triggering Minimum Requirements #1 through #9, must meet the requirements in Table 2.5.1. Table 1.5.1 Omsite Stormemter Management Recoirements for Prefects Triggering Minimum Requirements ki -�4 Project Fypearol Locadon Requirement New developmeut m any parcel inside the Low Impact Development Performance UGA or rinv development outside the Standard and 151,11? T5.13, or List ,2 UGA on a parcel less than 5 acres (applicant op —) New development outside the UGA on a Low Impact Detrlopment Performance Parcel of 5 acres or larger Standard and BhfP T5.13. Redecelopmeat on any parcel inside the Loin hnpact Development Performance UGA or tedenelopmemt outside the UGA Standard and SNIP T5.13: or List m2 on a parcel less than 5 acres (apphca of option). Redeveloprnent outside the UGA on a Low Impact Detelopment Perfomunce Parcel of 5 acres or larger Standard and Bhp T5.13_ NOTE: This table refers to the Urban Grnuth Area (LTGA) as designated under the >• Gi noon Uanagement Act (G]L{) (Chanter 36.70A RC Wl of the State of Washington. If the Permittee is located in a country that is not subject to planning under the GALA, the cin' limits shall be used instead. 18025 Drainage Report 4-4 ,. LID Performance Standard The project will utilize bioretention facilities to treat and infiltrate all runoff generated on-site. r MR #7 — Flow Control: Thresholds When assessing a project against the following thresholds, consider only those impervious, hard, and pervious surfaces that are subject to this minimum requirement as determined in Section 2.4 of this chapter. The following circumstances require achievement of the standard flow control requirement for western Washington: • Projects in which the total of effective impervious surfaces is 10,000 square feet or more in a threshold discharge area, or This project creates more than 10,000 square feet of effective impervious surface in its threshold discharge area. • Projects that convert % acres or more of vegetation to lawn or landscape, or convert 2.5 acres or more of native vegetation to pasture in a threshold discharge area, and from y which there is a surface discharge in a natural or man-made conveyance system from the site, or This project does not exceed this criterion. • Projects that through a combination of effective hard surfaces and converted vegetation areas cause a 0.10 cubic feet per second increase in the 100 -year flow frequency from a threshold discharge area as estimated using the Western Washington Hydrology Model or other approved model and one-hour time steps (ora 0.15 cfs increase using 15 -minute time steps). 2 This project exceeds the criterion. Standard Flow Control Requirement The LID Performance Standard will be met. Flow control will be provided via infiltration through the proposed bioretention facilities. MR #8 — Wetlands Protection: There are no wetlands within the proposed project limits. MR #9 — Operation & Maintenance: 18025 Drainage Report 4-5 An operation and maintenance agreement and manual will be included in the final drainage report and functions as a standalone document for the developer and property owners. MR #10 — Agreements and Financial Guarantees: Facility agreements and financial guarantees when required will be reviewed by the applicant and executed at the appropriate time determined by the reviewing agency. Supplemental Requirement SR#1 — Basin/Watershed Planning: There are no basin or watershed requirements for this project area. Supplemental Requirement SR#2 — Offsite Analysis and Mitigation The offsite analysis for this project did not yield any mitigation for this project. ,. Drainage Easements: No onsite easements are required or needed for this project's drainage facilities. Drainage Facility Setbacks: Bioretention Swales 10' from property line, 10' from any structure. Adjustments: No adjustments have been requested for this project. Exceptions and Variances: No variances are requested at this time. 18025 Drainage Report 4-6 PART 5 — PERMANENT STORMWATER CONTROL PLAN Existing Site Hydrology Existing site hydrology is based on our site investigation, field topographic survey, aerial topographic mapping and completed soils review for the subject project. The site consists of the _ basins outlined below. Pre -developed Basin (P#) Current Land Use: Vacant Lot Basin ID Land Use Assumptions and Site Parameters Land Use Cover Slope Acres Hydrologic Comments Grou P1 Forested Flat 5.81 A Gravel Flat 4.09 A P2 Forested Flat 4.22 A Roof Flat 0.09 A Lawn Flat 0.49 P3 Forested Flat 3.16 A D2 Parking Flat 0.81 A P4 Forested Flat 0.13 A Sidewalks Flat 0.04 A Total 13.32 Developed Site Hydrology (D#) The developed site hydrology was modeled using the latest version of the WWHM Continuous Simulation model created by WSDDE. A complete summary for each sub -basin is included in the chart below. Because of the existing topography, the site was able to be graded and modeled as one basin. Basin D1 includes all the new impervious surfaces created by the development of the project. Basin Summary Proposed Land Use: Residential — Multi -Family Housing 18025 Drainage Report 5-1 Land Use Assumptions and Site Parameters Basin ID Land Use Cover Slope Acres Hydrologic Group Comments D1 Parking Flat 1.14 A Gravel Flat 4.09 A Sidewalks Flat 0.00 A Roof Flat 0.09 A Lawn Flat 0.49 A D2 Parking Flat 0.81 A Gravel Flat 3.05 A Sidewalks Flat 0.04 A 18025 Drainage Report 5-1 Flow Control System Design S Analysis The proposed storm water facilities were designed using the WWHM storm water model created by WSDOE. Flow and Water Quality Control Facilities Proposed: Basin Roof Flat 0.06 A Water Quality/Flow D1 Lawn Flat 0.26 A Control D3 Parking Flat 0.00 A Gravel Flat 3.16 A Water Quality/Flow D3 Sidewalks Flat 0.00 A Control Roof Flat 0.00 A Lawn Flat 0.00 A D4 Frontage Im rovements Flat 0.13 A Total 13.32 Flow Control System Design S Analysis The proposed storm water facilities were designed using the WWHM storm water model created by WSDOE. Flow and Water Quality Control Facilities Proposed: Basin Facility Type Comments Water Quality/Flow D1 Bioretention Swale - 363'L X 3'W X 2.5'D Control Water Quality/Flow D2 Bioretention Swale - 4651 X 3'W X 2'D Control Water Quality/Flow D3 Bioretention Swale - 469'L X 3'W X 2'D Control Water Quality/Flow D4 Bioretention Control RBE conducted modeling of all basins using WWHM12 continuous simulation model. Listed below are narratives of each delineated drainage basin for this project. .. Basin Narratives Basin D1 Basin D1 encompasses the eastern half of the site and involves collecting, treating, and infiltrating all runoff generated within the basin by utilizing a 363 -foot long by 3' wide bioretention Swale. Basin D2 Basin D3 encompasses the southwestern quarter of the site and involves collecting, treating, and infiltrating all runoff generated within the basin by utilizing a 465 -foot long by 3 -foot wide bioretention Swale. 18025 Drainage Report 5-2 I Basin D3 Basin D3 encompasses the northwestern quarter of the site and involves collecting, treating, and infiltrating all runoff generated within the basin by utilizing a 400 -foot long by 3 -foot wide bioretention swale. Basin D4 Basin D4 encompasses the frontage improvements along Northern Pacific Road. Stormwater will be directed to the landscape beds for treatment and infiltration. An amended soil layer will be added to the beds to meet water quality standards. Basin D4 was not included in the stormwater modeling. 18025 Drainage Report 5-3 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 10 OF 17 PROJECT NO.: 18103 DATE: 2!7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #10 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 146' 7. CURRENTWATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 146° IMPERVIOUS/RESTRICTIVE Sloping %CL HORIZONS: IND CEM ROO <X> Greater than bottom of hole A 10. POTENTIAL FOR: EROSION RUNOFF PONDING <10 <40 1SBK - Slight Slight Minimal 11, SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: It is recommended that a design infiltration rete 220 m/hr be used for proposed stormwater infiltration facilities located in the C2 horizon soils. Winter water table was present at 146" below the existing rade. Soils Strata Description Soil Log #10 Horz Deoth Color Texture %CL %ORO CF STR MOT IND CEM ROO <X> FSP A 0"- 14" 10YR2/1 VGr/CobLm <25 <10 <40 1SBK - - - H 2-6 2 C1 14'- 28" 10YR3/4 ExGrM-FSa <i - <85 SG - - - If #0 >15 C2 28%156' 1OYR5/6 ExGr/CobCSa <1 - <90 SG - - - - >20 >2D SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET 11 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #11 STR MOT LOCATION: See test pit location map <X> 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace <10 foam(110) 1GBK - 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A Greater than bottom of hale 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: Greater than bottom IMPERVIOUS/RESTRICTIVE Nearly level of hole HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: It is recommended that a design infiltration rate < 20 m1hr be used for proposed stormwater infiltration facilities located in the C1 horizon soils. Winter water table was not present to 144" below the existing rade. Hole cave in. Soils Strata Description Soil Log #11 Horz Deoth Color Texture %CL %ORG CF STR MOT IND CEM ROO <X> FSP A 0"- 30" 10YR211 VGr/CobLm <25 <10 <40 1GBK - - - fm 2-6 2 C1 30"-144" 10YR5/2 ExGrCSa j <85 SG - - - fm >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 8 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #8 Texture LOCATION: See test pit location map 0'- 22' 1. TYPES OF TEST DONE. 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace <1 loam(110) - - >20 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outman GROUP: A 70' 7, CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 70' IMPERVIOUS/RESTRICTIVE Nearly level stones and HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: It is recommended that a design infiltration rate < 20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 70" below the existing rade. Soils Strata Description Horz Deoth Color Texture A 0'- 22' 10YR2/1 VGr/CobLm C1 2Y- 30' 10YR4/8 ExGr/CobC- <1 - <80 SG - - - - >20 FSa C2 30"-108' 10YR5/2 ExGr/CubC- MSa some stones and boulders Soils Strata Description Soil Log #8 %CL %ORG CF STR MOT IND CEM ROO <X> FSP <25 <10 <55 iSBK - - - R 2-8 2 <1 - <80 SG - - - - >20 >20 q - c85 SG - - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 9 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #9 VGrlCebl.m LOCATION: See test pit location map 23% 76" 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace <1 loam(110) - - - >20 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 112" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 112" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight I Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: It is recommended that a design infiltration rate 120 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 112' below the existing rade. Horz Deoth Color Texture A 0°- 23" 10YR2/1 VGrlCebl.m C1 23% 76" 1OYR416 ExGr/CobCSa C2 76"-144" 10YR5/2 ExGr/CobC- <1 - <85 SG - - - - >20 MSa some <1 - <80 SG - - - - >20 stones Soils Strata Description Soil Log #9 %CL %ORG CF STR MOT IND CEM ROO <x> FSP <25 <10 <40 1SBK - - - If 2-6 2 <1 - <85 SG - - - - >20 >20 <1 - <80 SG - - - - >20 >20 PART 5.1 — FLOW CONTROL Flow Control System Design & Analysis The proposed stormwater facility was designed using the professional version of the WWHM stormwater model created for WSDOE. The proposed site development was modeled using WWHM that resulted in the following pond volumes listed below. The WWHM data output also outlines the control structure dimensions and elevations. See WWHM data output for that information. Flow Control Facility Proposed: Bioretention Swale D1 Bioretention Swale Design Summary The proposed swale is approximately 363 feet long x 3 feet wide x 2.5 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site Plan Review. Flow Control Facility Proposed: Bioretention Swale D2 Bioretention Swale Design Summary Swale Stage Storage Elevation ft Detention Volume ac -ft) Top of Swale Top of Swale 332.5 0.22 333.0 0.12 Design Water Surface 332.0 0.15 Bottom Live Storage 330.0 0 The proposed swale is approximately 363 feet long x 3 feet wide x 2.5 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site Plan Review. Flow Control Facility Proposed: Bioretention Swale D2 Bioretention Swale Design Summary The proposed swale is approximately 465 feet long x 3 feet wide x 2 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site Plan Review. Flow Control Facility Proposed: Bioretention Swale D3 Bioretention Swale Design Summary Swale Stage Storage Elevation ftDetention Volume ac-ft Detention Volume (ac -ft) Top of Swale 333.5 0.20 332.5 Design Water Surface 333.0 0.12 Desi n Water Surface1 Bottom Live Storage 331.5 0 Bottom Live Storage 1 330.5 The proposed swale is approximately 465 feet long x 3 feet wide x 2 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site Plan Review. Flow Control Facility Proposed: Bioretention Swale D3 Bioretention Swale Design Summary The proposed swale is approximately 469 feet long x 3 feet wide x 2 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site 18025 Drainage Report 5.1-1 Swale Stage Storage Elevation ft Detention Volume (ac -ft) Top of Swale 332.5 0.19 Desi n Water Surface1 332.0 0.12 Bottom Live Storage 1 330.5 0 The proposed swale is approximately 469 feet long x 3 feet wide x 2 feet deep. The final dimensions will be detailed in the final construction drawings prepared after approval of the Site 18025 Drainage Report 5.1-1 Plan Review WWHM Data Output The following figures and WWHM modeling data output are included on the following pages of this section: WWHM Modeling Data Output WWRM2012 PROJECT REPORT Project Name: Basin 1 Site Name: BASIN 1 Site Address: 939 Northern Pacific Rd City : Yelm Report Date: 6/6/2018 Gage : Lake Lawrence Data Start : 1955/10/01 00:00 Data End : 2008/09/30 00:00 Precip Scale: 0.86 Version Date: 2018/03/02 Version : 4.2.14 Low Flow Threshold for POC 1 : e Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Basin 1 Bypass: No Groundwater: No Pervious Land Use acre A B, Forest, Flat 5.81 Pervious Total 5.81 Impervious Land Use acre Impervious Total 0 Basin Total 5.81 Element Flows To: 18025 Drainage Report 5.1-2 Surface Interflow Groundwater Element Flows To: » Surface Interflow Groundwater Surface retention 1 Surface retention 1 Name Biorstention 1 Bottom Length: 363.00 ft. Bottom Width: 3.00 ft. Material thickness of first layer: 1.5 Material type for first layer: SMMWW 12 in/hr Material thickness of second layer: 0 Material type for second layer: GRAVEL Material thickness of third layer: D Material type for third layer: GRAVEL _ Infiltration On Infiltration rate: 20 Infiltration safety factor: 1 Wetted surface area On +� Total Volume Infiltrated (ac -£t.): 945.045 Total Volume Through Riser (ac -ft.): 0.044 Total Volume Through Facility (ac -ft.): 945.089 Percent Infiltrated: 100 Total Precip Applied to Facility: 14.211 Total Evap From Facility: 3.407 Underdrain not used r Discharge Structure 18025 Drainage Report 5.1-3 MITIGATED LAND USE Name : Basin 1 Bypass: No Groundwater: No Pervious Land Use acre A B, Lawn, Flat .49 Pervious Total 0.49 Impervious Land Use acre ROOF TOPS PLAT 0.09 PARKING FLAT 5.23 Impervious Total 5.32 Basin Total 5.81 Groundwater Element Flows To: » Surface Interflow Groundwater Surface retention 1 Surface retention 1 Name Biorstention 1 Bottom Length: 363.00 ft. Bottom Width: 3.00 ft. Material thickness of first layer: 1.5 Material type for first layer: SMMWW 12 in/hr Material thickness of second layer: 0 Material type for second layer: GRAVEL Material thickness of third layer: D Material type for third layer: GRAVEL _ Infiltration On Infiltration rate: 20 Infiltration safety factor: 1 Wetted surface area On +� Total Volume Infiltrated (ac -£t.): 945.045 Total Volume Through Riser (ac -ft.): 0.044 Total Volume Through Facility (ac -ft.): 945.089 Percent Infiltrated: 100 Total Precip Applied to Facility: 14.211 Total Evap From Facility: 3.407 Underdrain not used r Discharge Structure 18025 Drainage Report 5.1-3 Riser Height: 2 £t. Riser Diameter: 24 in. Element Flow To: Outlet 1 Outlet 2 Hioretention 1 Hydraulic Table Stage (feet) Area (ac) Volume(a,ft.) Diecharge(cfe) Infilt(cfe) r 0.0000 0.1025 0.0000 0.0000 0.0000 0.0440 0.1022 0.0005 0.0000 0.0000 0.0879 0.0999 0.0011 0.0000 0.0001 0.1319 0.0975 0.0017 0.0000 0.0003 0.1758 0.0952 0.0024 0.0000 0.0005 0.2198 0.0929 0.0031 0.0000 0.0010 0.2637 0.0906 0.0038 0.0000 0.0016 r 0.3077 0.0883 0.0046 0.0000 0.0024 0.3516 0.0860 0.0055 0.0000 0.0036 0.3956 0.0837 0.0063 0.0000 0.0050 0.4396 0.0814 0.0073 0.0000 0.0068 0.4835 0.0791 0.0082 0.0000 0.0090 0.5275 0.0768 0.0093 0.0000 0.0117 0.5714 0.0745 0.0103 0.0000 0.0149 0.6154 0.0722 0.0114 0.0000 0.0186 0.6593 0.0700 0.0126 0.0000 0.0230 0.7033 0.0677 0.0138 0.0000 0.0280 0.7473 0.0654 0.0150 0.0000 0.0337 i 0.7912 0.0631 0.0163 0.0000 0.0403 0.8352 0.0609 0.0177 0.0000 0.0477 0.8791 0.0586 0.0190 0.0000 0.0560 r 0.9231 0.0563 0.0205 0.0000 0.0653 0.9670 0.0541 0.0219 0.0000 0.0756 1.0110 0.0518 0.0235 0.0000 0.0871 1.0549 0.0496 0.0250 0.0000 0.0997 r 1.0989 0.0473 0.0267 0.0000 0.1136 1.1429 0.0451 0.0283 0.0000 0.1287 1.1868 0.0428 0.0300 0.0000 0.1453 1.2308 0.0406 0.0318 0.0000 0.1634 1.2747 0.0384 0.0336 0.0000 0.1829 1.3187 0.0361 0.0354 0.0000 0.2041 1.3626 0.0339 0.0373 0.0000 0.2270 1.4066 0.0317 0.0392 0.0000 0.2517 1.4505 0.0294 0.0412 0.0000 0.2782 1.4945 0.0272 0.0433 0.0000 0.3065 1.5000 0.0250 0.0435 0.0000 0.3065 Surface retention 1 Hydraulic Table Staae(feet) Area(s .) Volu (ac -£t.) Diecharge(cfe) To Acended(cfe) wetted Surface 1.5000 0.1025 0.0435 0.0000 0.3114 0.0469 1.5440 0.1048 0.0481 0.0000 0.3114 0.0939 1.5879 0.1071 0.0527 0.0000 0.3202 0.1409 1.6319 0.1095 0.0575 0.0000 0.3291 0.1881 + 18025 Drainage Report 5.1-4 18025 Drainage Report 5.1-5 1.6758 0.1118 0.0623 0.0000 0.3380 0.2352 _ 1.7198 0.1141 0.0673 0.0000 0.3468 0.2825 1.7637 0.1165 0.0724 0.0000 0.3557 0.3298 1.8077 0.1188 0.0776 0.0000 0.3646 0.3772 1.8516 0.1212 0.0828 0.0000 0.3734 0.4246 1.8956 0.1235 0.0882 0.0000 0.3823 0.4721 1.9396 0.1259 0.0937 0.0000 0.3911 0.5196 1.9835 0.1282 0.0993 0.0000 0.4000 0.5673 ' 2.0275 0.1306 0.1050 0.0000 0.4089 0.6150 2.0714 0.1330 0.1108 0.0000 0.4177 0.6627 2.1154 0.1353 0.1167 0.0000 0.4266 0.7105 ,., 2.1593 0.1377 0.1227 0.0000 0.4355 0.7584 2.2033 0.1401 0.1288 0.0000 0.4443 0.8064 2.2473 0.1425 0.1350 0.0000 0.4532 0.8544 2.2912 0.1448 0.1413 0.0000 0.4621 0.9025 2.3352 0.1472 0.1477 0.0000 0.4709 0.9506 2.3791 0.1496 0.1542 0.0000 0.4798 0.9988 2.4231 0.1520 0.1609 0.0000 0.4887 1.0471 2.4670 0.1544 0.1676 0.0000 0.4975 1.0954 s 2.5110 0.1568 0.1744 0.0000 0.5064 1.1438 2.5549 0.1592 0.1814 0.0000 0.5152 1.1923 2.5989 0.1616 0.1884 0.0000 0.5241 1.2408 2.6429 0.1640 0.1956 0.0000 0.5330 1.2894 2.6868 0.1664 0.2028 0.0000 0.5418 1.3381 2.7308 0.1688 0.2102 0.0000 0.5507 1.3868 2.7747 0.1712 0.2177 0.0000 0.5596 1.4356 ' 2.8187 0.1737 0.2253 0.0000 0.5684 1.4844 2.8626 0.1761 0.2330 0.0000 0.5773 1.5333 2.9066 0.1785 0.2407 0.0000 0.5862 1.5823 2.9505 0.1809 0.2486 0.0000 0.5950 1.6314 2.9945 0.1834 0.2567 0.0000 0.6039 1.6805 3.0385 0.1858 0.2648 0.0000 0.6128 1.7296 3.0824 0.1882 0.2730 0.0000 0.6216 1.7789 ' 3.1264 0.1907 0.2813 0.0000 0.6305 1.8282 3.1703 0.1931 0.2898 0.0000 0.6394 1.8776 3.2143 0.1956 0.2983 0.0000 0.6482 1.9270 3.2582 0.1980 0.3069 0.0000 0.6571 1.9765 3.3022 0.2005 0.3157 0.0000 0.6659 2.0260 3.3462 0.2029 0.3246 0.0000 0.6748 2.0757 3.3901 0.2054 0.3335 0.0000 0.6837 2.1253 3.4341 0.2079 0.3426 0.0000 0.6925 2.1751 3.4780 0.2103 0.3518 0.0000 0.7014 2.2249 3.5220 0.2128 0.3611 0.0692 0.7103 2.2748 3.5659 0.2153 0.3705 0.3591 0.7191 2.3247 r 3.6099 0.2178 0.3800 0.7719 0.7280 2.3748 3.6538 0.2202 0.3897 1.2766 0.7369 2.4248 3.6978 0.2227 0.3994 1.8560 0.7457 2.4750 3.7418 0.2252 0.4093 2.4970 0.7546 2.5252 3.7857 0.2277 0.4192 3.1878 0.7635 2.5754 3.8297 0.2302 0.4293 3.9171 0.7723 2.6258 3.8736 0.2327 0.4394 4.6731 0.7812 2.6762 ' 3.9176 0.2352 0.4497 5.4440 0.7900 2.7266 3.9615 0.2377 0.4601 6.2177 0.7989 2.7708 4.0000 0.2399 0.4693 6.9822 0.8067 1.5333 18025 Drainage Report 5.1-5 Name Surface retention 1 Element Flows To: Outlet 1 Outlet 2 Hioretention 1 r ANALYSIS RESULTS POC $1 was not reported because POC must exist in both scenarios and both scenarios must have been run.Perind and Impind Changes No changes have been made. This program and accompanying documentation are provided ., r - without x r ant, of any kind. The entire risk regarding the performance andr sults of this program i assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed o r implied, including but not limited to implied warranties of program and daccompanying 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 uad 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. 2005-2016; All Rights Reserved. y 18025 Drainage Report 5.1-6 WNHM2012 PROJECT REPORT Project Name: Basin 2 Site Name: BASIN 2 Site Address: 939 Northern Pacific Ad r city : Yelm WA Report Date: 6/6/2018 Gage : Lake Lawrence Data Start : 1955/10/01 00:00 Data End : 2008/09/30 00:00 Precip Scale: 0.86 Version Date: 2018/03/02 Version : 4.2.14 Low Flow Threshold for POC 1 : 8 Percent of the 2 Year High Flow Threshold for POC 1: 50 year MITIGATED LAND USE Name Basin 1 Bypass: No Groundwater 18025 Drainage Report 5.1-7 PREDEVELOPED LAND USE Name : Basin 1 r Bypass: No Groundwater: No Pervious Land Use acre A B, Forest, Flat 4.22 Pervious Total 4.22 Impervious Land Use acre Impervious Total 0 Basin Total 4.22 r Element Flows To: Surface Interflow MITIGATED LAND USE Name Basin 1 Bypass: No Groundwater 18025 Drainage Report 5.1-7 GroundWater: No Pervious Land Use acre A B, Lawn, Flat .26 Pervious Total 0.26 Impervious Land Use acre ROOF TOPS FLAT 0.06 SIDEWALKS FLAT 0.04 PARKING FLAT 3.86 i Impervious Total 3.96 Basin Total 4.22 Element Flows To: Surface Inter£low Groundwater Surface retention 1 Surface retention 1 Name Eioretention 1 Bottom Length: 465.00 ft. Bottom Width: 3.00 ft. Material thickness of first layer: 1.5 Material type for first layer: SMMWW 12 in/hr Material thickness of second layer: 0 Material type for second layer: Sand Material thickness of third layer: 0 Material type for third layer: GRAVEL Infiltration On Infiltration rate: 20 Infiltration safety factor: 1 Wetted surface area On Total volume Infiltrated (ac -ft.): 705.783 Total volume Through Riser (ac -£t.): 0 Total volume Through Facility (ac -ft.): 705.783 Percent Infiltrated: 100 Total Precip Applied to Facility: 14.438 Total Evap From Facility: 4.104 Underdrain not used Discharge Structure Riser Height: 1.5 ft. Riser Diameter: 18 in. Element Flows To: Outlet 1 Outlet 2 18025 Drainage Report 5.1-8 Stage(feet) Bioretention 1 Hydraulic Table Area(ac.) Volume(aoft.) Diecharge(cfe) Infilt(cfe) 0.0000 0.1306 To Anonded(cfe) 0.0000 1.5000 0.0000 0.0000 0.0385 0.1280 0.3974 0.0006 0.0519 0.0000 1.5385 0.0000 0.0769 0.1254 0.0000 0.0012 0.3974 0.0000 0.1039 0.0001 1.5769 0.1154 0.1229 0.0658 0.0019 0.0000 0.0000 0.4074 0.0002 0.1560 0.1538 0.1203 0.1383 0.0026 0.0711 0.0000 0.0000 0.0005 0.4173 0.1923 0.1177 0.0034 0.1409 0.0000 0.0764 0.0009 0.0000 0.2308 0.1152 0.0042 0.0000 0.1435 0.0014 0.0819 0.2692 0.1126 0.0050 0.0000 0.0021 0.1461 0.3077 0.1101 0.0059 0.0000 0.0031 0.3462 0.1075 0.0068 0.0000 0.0044 0.3846 0.1050 1.8077 0.0078 0.0000 0.0059 0.4231 0.1024 0.4693 0.0088 0.0000 0.0078 0.4615 0.0999 0.0099 0.0000 18025 0.0100 0.5000 0.0973 Report 0.0110 0.0000 5.1-9 0.0127 0.5385 0.0948 0.0122 0.0000 0.0159 0.5769 0.0922 0.0134 0.0000 0.0196 0.6154 0.0897 0.0146 0.0000 0.0238 0.6538 0.0872 0.0159 0.0000 0.0286 0.6923 0.0846 0.0172 0.0000 0.0341 0.7308 0.0821 0.0186 0.0000 0.0402 0.7692 0.0796 0.0200 0.0000 0.0472 0.8077 0.0770 0.0215 0.0000 0.0549 0.8462 0.0745 0.0230 0.0000 0.0635 0.8846 0.0720 0.0246 0.0000 0.0729 0.9231 0.0695 0.0262 0.0000 0.0834 0.9615 0.0670 0.0278 0.0000 0.0948 1.0000 0.0645 0.0295 0.0000 0.1074 1.0385 0.0620 0.0312 0.0000 0.1210 1.0769 0.0594 0.0330 0.0000 0.1359 1.1154 0.0569 0.0348 0.0000 0.1520 1.1538 0.0544 0.0367 0.0000 0.1694 1.1923 0.0519 0.0386 0.0000 0.1881 1.2308 0.0494 0.0406 0.0000 0.2084 1.2692 0.0469 0.0426 0.0000 0.2301 1.3077 0.0445 0.0446 0.0000 0.2533 1.3462 0.0420 0.0467 0.0000 0.2782 1.3846 0.0395 0.0489 0.0000 0.3048 1.4231 0.0370 0.0511 0.0000 0.3331 1.4615 0.0345 0.0533 0.0000 0.3633 1.5000 0.0320 0.0556 0.0000 0.3633 Surface retention 1 Hydraulic Table Stage(feet) Area(ac.) Volo -(ac -ft.) Diecharge(efe) To Anonded(cfe) wetted Surface 1.5000 0.1306 0.0556 0.0000 0.3974 0.0519 1.5385 0.1332 0.0606 0.0000 0.3974 0.1039 1.5769 0.1357 0.0658 0.0000 0.4074 0.1560 1.6154 0.1383 0.0711 0.0000 0.4173 0.2081 1.6538 0.1409 0.0764 0.0000 0.4272 0.2602 1.6923 0.1435 0.0819 0.0000 0.4372 0.3124 1.7308 0.1461 0.0875 0.0000 0.4471 0.3647 1.7692 0.1487 0.0931 0.0000 0.4571 0.4170 1.8077 0.1513 0.0989 0.0000 0.4670 0.4693 18025 Drainage Report 5.1-9 18025 Drainage Report 5.1-10 1.8462 0.1538 0.1048 0.0000 0.4769 0.5217 + 1.8846 0.1564 0.1107 0.0000 0.4869 0.5741 1.9231 0.159D 0.1168 0.0000 0.4968 0.6266 1.9615 0.1617 0.1230 0.0000 0.5067 0.6792 + 2.0000 0.1643 0.1292 0.0000 0.5167 0.7318 2.0385 0.1669 0.1356 0.0000 0.5266 0.7844 2.0769 0.1695 0.1421 0.0000 0.5365 0.8371 + 2.1154 0.1721 0.1487 0.0000 0.5465 0.8898 2.1538 0.1747 0.1553 0.0000 0.5564 0.9426 2.1923 0.1773 0.1621 0.0000 0.5663 0.9954 2.2306 0.1799 0.1690 0.0000 0.5763 1.0483 + 2.2692 0.1826 0.1759 0.0000 0.5862 1.1013 2.3077 0.1852 0.1830 0.0000 0.5962 1.1542 2.3462 0.1878 0.1902 0.0000 0.6061 1.2073 2.3846 0.1904 0.1975 0.0000 0.6160 1.2604 + 2.4231 0.1931 0.2048 0.0000 0.6260 1.3135 2.4615 0.1957 0.2123 0.0000 0.6359 1.3667 2.5000 0.1983 0.2199 0.0000 0.6458 1.4199 + 2.5385 0.2010 0.2276 0.0000 0.6556 1.4732 2.5769 0.2036 0.2353 0.0000 0.6657 1.5265 2.6154 0.2063 0.2432 0.0000 0.6756 1.5799 2.6538 0.2089 0.2512 0.0000 0.6856 1.6333 + 2.6923 0.2116 0.2593 0.0000 0.6955 1.6868 2.7308 0.2142 0.2675 0.0000 0.7054 1.7403 2.7692 0.2169 0.2758 0.0000 0.7154 1.7939 2.8077 0.2195 0.2842 0.0000 0.7253 1.8475 + 2.8462 0.2222 0.2927 0.0000 0.7353 1.9012 2.8846 0.2249 0.3013 0.0000 0.7452 1.9549 2.9231 0.2275 0.3100 0.0000 0.7551 2.0087 2.9615 0.2302 0.3188 0.0000 0.7651 2.0625 3.0000 0.2329 0.3277 0.0000 0.7750 2.1164 3.0385 0.2355 0.3367 0.1200 0.7849 2.1703 3.0769 0.2382 0.3458 0.3391 0.7949 2.2243 + 3.1154 0.2409 0.3550 0.6219 0.8048 2.2783 3.1538 0.2436 0.3643 0.9542 0.8147 2.3323 3.1923 0.2462 0.3737 1.3261 0.8247 2.3865 + 3.2308 0.2489 0.3833 1.7286 0.8346 2.4406 3.2692 0.2516 0.3929 2.1526 0.8446 2.4948 3.3077 0.2543 0.4026 2.5691 0.8545 2.5491 3.3462 0.2570 0.4124 3.0289 0.8644 2.6034 + 3.3846 0.2597 0.4224 3.4625 0.8744 2.6578 3.4231 0.2624 0.4324 3.8809 0.8843 2.7122 3.4615 0.2651 0.4426 4.2756 0.8942 2.7667 3.5000 0.2678 0.4528 4.6391 0.9042 2.7667 3.5000 0.2678 0.4528 4.9654 0.9042 0.0000 + Name Surface retention 1 element Flows To: Outlet 1 Outlet 2 Bioretention 1 18025 Drainage Report 5.1-10 ANALYSIS RESULTS POC #1 was not reported because POC must exist in both scenarios and both scenarios must have been run.Perind and Impind Changes No changes have been made. This program and accompanying documentation are provided r - without warranty of any kind. The entire risk regarding the performance ande results of thisprogram i med by had past. Clear Creek Solutions Inc. and the governmental licensee o sublicensees disclaim all warranties, either expressed o 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, lose of business information, business interruption, and the like) arising out be the u of, or n ' inability to use this program e 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. 2005-2018; All Rights Reserved. 18025 Drainage Report 5.1-11 WWHM2012 PROJECT REPORT Project Name: Basin 3 Site Name: BASIN 3 Site Address: 939 Northern Pacific Rd City : Yetm WA Report Date: 6/6/2018 Gage : Lake Lawrence Data Start : 1955/10/01 00:00 Data End : 2008/09/30 00:00 Precip Scale: 0.86 Version Date: 2018/03/02 Version : 4.2.14 Low Flow Threshold for POC 1 : 8 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre A B, Forest, Flat 3.16 Pervious Total 3.16 Impervious Land Use acre Impervious Total 0 Basin Total 3.16 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE Name Basin 1 Bypass: No 18025 Drainage Report 5.1-12 ,o Groundwater: No Pervious Land Use acre + Pervious Total 0 Impervious Land Use acre PARKING FLAT 3.16 Impervious Total 3.16 + Basin Total 3.16 Element Flows To: Surface Interflow Groundwater + Surface retention 1 Surface retention 1 Bioretention 1 Hydraulic Table Stage(feet) Area(ac.) Volu (ac -ft.) Discharge(cfs) Infilt(cfs) 18025 Drainage Report 5.1-13 Name : Bioretention 1 Bottom Length: 469.00 ft. Bottom Width: 3.00 ft. Material thickness of first layer: 1.5 Material type for first layer: SMMww 12 in/hr Material thickness of second layer: 0 Material type for second layer: Sand + Material thickness of third layer: 0 Material type for third layer: GRAVEL Infiltration On Infiltration rate: 20 _ Infiltration safety factor: 1 Wetted surface area On Total Volume Infiltrated (ac -ft.): 563.52 + Total Volume Through Riser (ac -ft.): 0 Total Volume Through Facility (ac -ft.): 563.52 Percent Infiltrated: 100 Total Precip Applied to Facility: 12.798 ` Total Evap From Facility: 3.998 Underdrain not used Discharge Structure Riser Height: 1.5 ft. Riser Diameter: 18 in. Element Flows To: Outlet 1 Outlet 2 Bioretention 1 Hydraulic Table Stage(feet) Area(ac.) Volu (ac -ft.) Discharge(cfs) Infilt(cfs) 18025 Drainage Report 5.1-13 18025 Drainage Report 5.1-14 0.0000 0.1317 0.0000 0.0000 0.0000 0.0385 0.1291 0.0006 0.0000 0.0000 0.0769 0.1265 0.0012 0.0000 0.0001 0.1154 0.1239 0.0019 0.0000 0.0002 0.1538 0.1213 0.0026 0.0000 0.0005 0.1923 0.1187 0.0034 0.0000 0.0009 0.2308 0.1161 0.0042 0.0000 0.0014 0.2692 0.1136 0.0051 0.0000 0.0022 + 0.3077 0.1110 0.0060 0.0000 0.0031 0.3462 0.1084 0.0069 0.0000 0.0044 0.3846 0.1058 0.0079 0.0000 0.0059 + 0.4231 0.1033 0.0089 0.0000 0.0078 0.4615 0.1007 0.0100 0.0000 0.0101 0.5000 0.0981 0.0111 0.0000 0.0128 0.5385 0.0956 0.0123 0.0000 0.0160 + 0.5769 0.0930 0.0135 0.0000 0.0197 0.6154 0.0905 0.0147 0.0000 0.0240 0.6538 0.0879 0.0160 0.0000 0.0288 + 0.6923 0.0854 0.0174 0.0000 0.0344 0.7308 0.0828 0.0188 0.0000 0.0406 0.7692 0.0803 0.0202 0.0000 0.0476 0.8077 0.0777 0.0217 0.0000 0.0554 0.8462 0.0752 0.0232 0.0000 0.0640 0.8846 0.0726 0.0248 0.0000 0.0736 0.9231 0.0701 0.0264 0.0000 0.0841 0.9615 0.0675 0.0281 0.0000 0.0956 + 1.0000 0.0650 0.0298 0.0000 0.1083 1.0385 0.0625 0.0315 0.0000 0.1220 1.0769 0.0600 0.0333 0.0000 0.1370 + 1.1154 0.0574 0.0351 0.0000 0.1532 1.1538 0.0549 0.0370 0.0000 0.1708 1.1923 0.0524 0.0390 0.0000 0.1897 1.2308 0.0499 0.0409 0.0000 0.2101 _ 1.2692 0.0473 0.0430 0.0000 0.2320 1.3077 0.0448 0.0450 0.0000 0.2555 1.3462 0.0423 0.0471 0.0000 0.2806 ,. 1.3846 0.0398 0.0493 0.0000 0.3074 1.4231 0.0373 0.0515 0.0000 0.3360 1.4615 0.0348 0.0537 0.0000 0.3663 1.5000 0.0323 0.0560 0.0000 0.3663 Surface retention 1 Hydraulic Table Sta4e(feet) Area(ac.) rola (ac -ft) Uiecharge(cfe) To A ended(cfe) Wetted Suzface 1.5000 0.1317 0.0560 0.0000 0.4009 0.0524 + 1.5385 0.1343 0.0611 0.0000 0.4009 0.1048 1.5769 0.1369 0.0664 0.0000 0.4109 0.1573 1.6154 0.1395 0.0717 0.0000 0.4209 0.2098 +� 1.6538 0.1421 0.0771 0.0000 0.4309 0.2624 1.6923 0.1447 0.0826 0.0000 0.4409 0.3150 1.7308 0.1473 0.0882 0.0000 0.4510 0.3677 1.7692 0.1499 0.0939 0.0000 0.4610 0.4204 1.8077 0.1525 0.0997 0.0000 0.4710 0.4732 1.8462 0.1551 0.1057 0.0000 0.4810 0.5260 1.8846 0.1578 0.1117 0.0000 0.4910 0.5788 1.9231 0.1604 0.1178 0.0000 0.5011 0.6318 18025 Drainage Report 5.1-14 ANALYSIS RESULTS 18025 Drainage Report 5.1-15 1.9615 0.1630 0.1240 0.0000 0.5111 0.6847 r 2.0000 0.1656 0.1303 0.0000 0.5211 0.7377 2.0385 0.1683 0.1368 0.0000 0.5311 0.7908 2.0769 0.1709 0.1433 0.0000 0.5412 0.8439 2.1154 0.1735 0.1499 0.0000 0.5512 0.8971 2.1538 0.1762 0.1566 0.0000 0.5612 0.9503 2.1923 0.1788 0.1635 0.0000 0.5712 1.0036 2.2308 0.1814 0.1704 0.0000 0.5812 1.0569 r 2.2692 0.1841 0.1774 0.0000 0.5913 1.1102 2.3077 0.1867 0.1845 0.0000 0.6013 1.1636 2.3462 0.1894 0.1918 0.0000 0.6113 1.2171 .� 2.3846 0.1920 0.1991 0.0000 0.6213 1.2706 2.4231 0.1947 0.2066 0.0000 0.6313 1.3242 2.4615 0.1973 0.2141 0.0000 0.6414 1.3778 2.5000 0.2000 0.2217 0.0000 0.6514 1.4314 _ 2.5385 0.2027 0.2295 0.0000 0.6614 1.4851 2.5769 0.2053 0.2373 0.0000 0.6714 1.5389 2.6154 0.2080 0.2453 0.0000 0.6815 1.5927 0 2.6538 0.2107 0.2533 0.0000 0.6915 1.6466 2.6923 0.2133 0.2615 0.0000 0.7015 1.7005 2.7308 0.2160 0.2697 0.0000 0.7115 1.7544 2.7692 0.2187 0.2781 0.0000 0.7215 1.8084 2.8077 0.2214 0.2866 0.0000 0.7316 1.8625 2.8462 0.2240 0.2951 0.0000 0.7416 1.9166 2.8846 0.2267 0.3038 0.0000 0.7516 1.9707 2.9231 0.2294 0.3126 0.0000 0.7616 2.0249 2.9615 0.2321 0.3214 0.0000 0.7716 2.0792 3.0000 0.2348 0.3304 0.0000 0.7817 2.1335 3.0385 0.2375 0.3395 0.1200 0.7917 2.1878 3.0769 0.2402 0.3487 0.3391 0.8017 2.2422 3.1154 0.2429 0.3580 0.6219 0.8117 2.2967 3.1538 0.2456 0.3674 0.9542 0.8218 2.3512 3.1923 0.2483 0.3769 1.3261 0.8318 2.4057 3.2308 0.2510 0.3865 1.7286 0.8418 2.4603 3.2692 0.2537 0.3962 2.1526 0.8518 2.5149 3.3077 0.2564 0.4060 2.5891 0.8618 2.5696 3.3462 0.2591 0.4159 3.0289 0.8719 2.6244 3.3846 0.2618 0.4259 3.4625 0.8819 2.6792 3.4231 0.2645 0.4360 3.8809 0.8919 2.7340 3.4615 0.2673 0.4462 4.2756 0.9019 2.7889 3.5000 0.2700 0.4566 4.6391 0.9119 2.7889 3.5000 0.2700 0.4566 4.9654 0.9119 0.0000 Name Surface retention 1 Element Flows To: Outlet 1 Outlet 2 Bioretention 1 ANALYSIS RESULTS 18025 Drainage Report 5.1-15 POC #1 was not reported because POC must exist in both scenarios and both scenarios must have been run.Perind and Impind Changes No changes have been made. This program and accompanying documentation are provided r - without warranty of any kind. r The entire risk regarding the performance andr sults of this program i r. assumed by End Use Clear Creek Solutions Inc. and the governmental licensee of sublicensees disclaim all warranties, either expressed o r implied, including but not limited to implied warranties of program and ompanying 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 bus Information, bus interruption, and the like) Ing out of the of, or mess mess ares use inability to use this program e if Clear Creek Solutions Inc. ge their authorized representativesCreekSol have been advised of the possibility er such damages. Software Copyright ° by Cie., Creek Solutions, Inc. 2005-2018; All Rights Reserved. 18025 Drainage Report 5.1-16 PART 5.2 — WATER QUALITY DESIGN Water Quality System Design & Analysis The drainage basins delineated for this project will have openly exposed pollution generating impervious surfaces. These tributary areas will be treated using the following treatment technologies listed under the associated drainage basins. Determine the Receiving Waters/Pollutants of concern based on Offsite Analyses Pollutants of Concern Step 2: Oil Control Facility This project will be required to provide oil control facility based on the analysis below. Oil Control Determination Chart ADT 100 Vehicles or Greater per 1000 SF Building Area Yes or No Site Subject to Petroleum Storage or Transfer Greater than 1500 Yes or No Gallons per year. Site have Parking, Storage or maintenance of 25 or more vehicles over 25 Tons gross weight. (Trucks, Buses, Trains, Yes or No Heavy Equipment) Road Intersection with measured ADT of 25000 vehicles or more on main roadway and 15000 vehicles or more on Yes or No intersection roadway. Step 3: Is Infiltration Practicable for pollutant removal? No Step 4: Phosphorus Control Required Oil Control Determination Chart Local Government Require Phosphorus control Yes or No 18025 Drainage Report 5.2-1 .. Step 5: Enhanced Treatment Required Oil Control Determination Chart Site discharge directly to fresh waters or conveyance systems tributary to fresh waters? Yes or No Site uses infiltration strictly for flow control and the discharge is within 1.4 mile of fresh water designate foraquatic life? Yes or No Site an industrial project site? Yes or No Site a commercial project site? Yes or No Site a multi -family residential project site Yes or No UGA— Fully controlled and partially controlled limited access highways with AADT 15000 or greater No UGA - All other roads with and AADT of 7500 or greater. No Outside UGA - Roads with and AADT of 15,000 or greater unless discharging to a Strahler order Stream or large No Outside UGA - Road with an AADT of 30,000 or greater if discharging to a 411 Strahler order stream or larger. No Step 6: Select Basic/Enhanced Treatment Facility Based on the above determination the following Enhanced treatment requirements will be .. provided for this facility. Selected Treatment BMP's Basin D1 Water Quality Facility: BMP T7.30 — Bioretention Swale — Enhanced Water Quality Facility: BMP T11.11 — Coalescing Plate Oil Water Separator RBE has selected these treatment methods for water quality control for the new PGIS associated with the project. Below is the summary of results from the WWHM water quality model. Bio -Retention Swale 131 — (See WWHM Data Output in Part 5.1 for Model Data) Basin D2 Water Quality Facility: BMP T7.30 — Bioretention Swale — Enhanced Water Quality Facility: BMP T11.11 — Coalescing Plate Oil Water Separator RBE has selected this treatment method for water quality control for the new PGIS associated with the project. Below is the summary of results from the WWHM water quality model. Bio -Retention Swale D2 — (See WWHM Data Output in Part 5.1 for Model Data) + 18025 Drainage Report 5.2-2 Basin D3 Water Quality Facility: BMP T7.30 — Bioretention Swale - Enhanced RBE has selected this treatment method for water quality control for the new PGIS associated with the project. Below is the summary of results from the WWHM water quality model. Bio -Retention Swale D3 — (See WWHM Data Output in Part 5.1 for Model Data) Basin D4 Water Quality Facility: BMP T7.30 — Bioretention - Enhanced RBE has selected this treatment method for water quality control for the new PGIS associated with the project. This facility has not yet been modeled. 18025 Drainage Report 5.2-3 PART 5.3 — CONVEYANCE SYSTEM DESIGN Pipe Conveyance Design All onsite storm conveyance systems will be sized to accommodate the 25 -year storm flows. All proposed onsite storm drain pipe will vary from 8 to 24 inches in diameter and the minimum slope shall not be less than 0.5%. Final conveyance pipe type and sizes will be provided in the final drainage report. 18025 Drainage Report 5.3-1 PART 6—SOURCE CONTROL BMPS The following permanent source control BMPs will be utilized for this project and will be included in the final Operation and Maintenance Manual submitted prior to final project acceptance by the County. Landscape and Lawn Vegetation Management 18025 Drainage Report 6-1 M PART 7 — CONSTRUCTION SWPPP A stand-alone SWPPP will be prepared for this project and submitted with the final drainage report. 18025 Drainage Report 7-1 PART 8 — SPECIAL REPORTS AND STUDIES 1. Soils Report— Parnell Engineering, LLC 18025 Drainage Report 8-1 PE Parnell Engineering, LLC 10623 Hunters Lane S.E. Olympia, We. 98513 (360)491-3243 DATE: 6125118 LETTER OF TRANSMITTAL PROJECT NAME :NPR Holdings LLC Northern Pacific Road NW, Yelm, WA TPN:64300900200 SEND TO : RB Engineering PO Box 923 91 SW 13th St. Chehalis, WA 98532 PE PROJECT NUMBER: #18103 Atm : Michael Lesmeisler, EIT THESE ARE TRANSMITTED AS CHECKED BELOW: X❑ FOR YOUR USE ❑ AS REQUESTED FOR YOUR REVIEW& COMMENT n APPROVEDASNOTED FORYOURAPPROVAL F1 RETURNED FOR CORRECTIONS REMARKS: Michael, Please find the subject soils report. Contact me at 491-3243 should you have any questions. Thank -you TRANSMITTED BY: William Parnell NPR Holdings LLC Soils Report For Stormwater Drainage Design Purposes Site Address: 1000-1100+ block of Northern Pacific Road NW, Yelm WA TPN: 64300900200 Prepared For: NPR Holdings LLC 3655 E. Marginal Way S. Seattle, WA 98134 206-313-0256 Contact: Ubaida A. Mufrej Prepared By: Parnell Engineering, LLC 10623 Hunters Lane S.E. Olympia, WA 98513 (360) 491-3243 Contact: William Parnell, P.E. PE PARNELL ENGINEERING, LLC SOIL EVALUATION REPORT FORM 1: GENERAL SITE INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 1 OF 1 PE PROJECT N0.:18103 DATE: 5/25/18 PREPARED BY: William Parnell, P.E. 1.SITEADDRESS: 1000-1100± blockRNorthern Pacific Road NW.,,; i TPN: 64300900200 2. PROJECT DESCRIPTION: Vehicle storage yard with office buildings. 3. SITE DESCRIPTION: The 13.93 acre irregular shapetl parcel is currently unoccupied. Site topography is neatly level to gently sloping. Elevations range from a high of 338 ft. at the southcentral portion of the site to a low of 328 ft. at the NE corner of the site. Site vegetation consists of sparsely located conifer trees with a dominate scods bloom understory and some indigenous brush and field grass ground cover. The project site is bounded by rural residential property to the north, undeveloped property to the east, Northern Pacific Road NW to the south and a private driveway to the west. The on-site soils are mapped by the NRCS as a somewhat excessively drained Spanaway series soil formed in glacial outwash. 4. SUMMARY OF SOILS WORK PERFORMED: Seventeen lest pits were excavated by trackhoe to a maximum depth of 162" below the existing grade. Soils were inspected by entering and visually logging each test pit to a depth of four feet. Soils beyond four feet were inspected by examining backhoe tailings. Nine grain size analysis tests were completed on samples taken from lest pit #1 at 60", #2 at 60", #5 at 72", 98 at 72", #7 at 38', #13 at 72, #15 at 84", #16 at 60"and #17 at 66" below the existing grade. Test pit soil log data sheets, grain size analysis test results and Ksat design infiltration rate calculations are included in this report. 5. ADDITIONAL SOILS WORK RECOMMENDED: Additional its work should not be necessary unless drainage infiltration facilities are located outside the general area encompassed by the soil test pits. 6. FINDINGS: The Natural Resource Conservation Service soil survey far Thurston County mapped the on- site soils as a Spanaway gravelly sandy loam (110,111). All test pits confirmed the Spanaway series designation generally profiling gravelly sandy loam stratum soils underlain by extremely gravelly coarse sand substratum soils. Winter water table was present in all test pits except #11, #12 and #15 which were located at the highest point on the property. Grain size analysis tests and Ksat design infiltration rale calculations resulted in calculated infiltration rates of 208 in/hr for sample #1 taken at 60" below the existing grade in test pit #1, 345 in/hr for sample #2 taken at 60" below the existing grade in test pit #2, 128 in/hr for sample #3 taken at 72" below the existing grade in test pit #5, 99 in/hr for sample #4 taken at 72" below the existing grade in test pit #6, 114 m/hr for sample #5 taken at 36" below the existing grade in test pit #7, 780 in/hr for sample #6 taken at 72' below the existing grade in test pit #13, 555 m/hr for sample #7 taken at 84" below the existing grade in test pit #15, 1253 in/hr for sample #8 taken at 60" below the existing grade in test pit #16 and 410 in/hr for sample #9 taken at 66" below the existing grade in test pit #17. 7. RECOMMENDATIONS: The Spanaway soil series is a somewhat excessively drained soil that formed on terraces in glacial outwash. Infiltration rates are generally rapid in the substratum gravelly soils. It is recommended that a design infiltration rate 120 in/hr be used for all proposed stormwater infiltration facilities that are located in the C1 and C2 horizon soils as indicated in the attached soil log data sheets. Winter water table was identified and should be considered in the design of all infiltration facilities. Drainage facility infiltration surfaces must be properly protected from contamination by the fine-grained upper horizon soils and from compaction by construction site activities. Soils not properly protected will cause drainage infiltration facilities to rematureli fail. I hereby certify that I prepared this report, and conducted or supervised the performance of related work. I certify that I am qualified to do this work. t my work to be complete an accurate within the bounds of uncertainly inherent to the,pr a of s its science andp�rto be suitable for its intended use. SIGNED: DATE: zS f � m R SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 1 OF 17 PROJECT NO.: 18103 DATE: 217/2018 PREPARED BY: William Pannell, PE REVISED 512 512 01 8 SOIL LOG: #1 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace FxGr/CobCSa loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Oulwash GROUP: A 103" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 103" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grein size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 208 in/hr for sample #1 taken at 60" below the existing grade. It is recommended that a design infiltration rate < 20 Whir be used for proposed stormwater infiltration facilities located in the Ci horizon soils. Winter water table was present at 103" below the existing rade. Harz DePth Color Texture A 0'- 24' 10YR2/1 GIL. C1 24"- 86' 10YR4/6 FxGr/CobCSa aome atones and boulders C2 86"-132' t0YR512 ExGrCSa Soils Strata Description Soil Log #1 %CL %ORG CF STR MOT <25 <10 <26 1SBK - <1 _ 85 SG <1 - <80 SG IND CEM ROO OX-' FSP 2-6 2 20 >20 >20 20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 2 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Pamell, PE REVISED 5/25/2018 SOIL LOG: #2 LOCATION: See test pit location map 1. TYPES OF TEST DONE. 2. SGS SOILS SERIES: 3, LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 108" 7. CURRENTWATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 108" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11, SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 345 in/hr for sample #2 taken at 60" below the existing grade. It is recommended that a design infiltration rate < 20 Whir be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 108" below the exasting grade. Horz Depth Color A 0"- 18" 10YR2/1 C1 18"- 40" 10YR4/6 C2 40'-142' 10YR512 Soils Strata Description Soil Log #2 Texture ACL %ORG CF STR MOT IND CEM ROO VGr/CobLm <25 <10 <40 1SBK - - - H aGdCobCSa <1 - <80 SG - - H some stones EZGr/CobCSa <1 - <85 SG - - - some stones <x> FSP M 2 >20 20 >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 3 OF 17 PROJECT NO.: 18103 DATE: 217/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #3 VGrLm LOCATION: See test pit location map 24"- 42" 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace <20 loam(110) - - 6 2-6 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 125" 7. CURRENT WATER 8. DEPTH TO g. MISCELLANEOUS: DEPTH: 125" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: his recommended that a design infiltration rate < 20 n1hr be used for proposed stormwater infiltration facilities located in the C horizon soils. Winter water table was resent at 125" below the existing rade. Horz Depth Color Texture A 0'- 24" 10YR211 VGrLm Bw 24"- 42" 10YR3/3 GrSaLm C1 42"-14F 10YR5/6 ExGr/CobC- <20 <6 <25 1SBK - - - 6 2-6 MSa some <t - <76 SG - - - - >20 stones Soils Strata Description Soil Log #3 %CL %ORG CF STR MOT IND CEM ROO <X> FSP <25 <10 140 1SBK - - - If 2-6 2 <20 <6 <25 1SBK - - - 6 2-6 4 <t - <76 SG - - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 4 OF 17 Color DATE: 2/7/2018 PROJECT NO.: 18103 REVISED 5/25/2018 PREPARED BY: William Parnell, PE VGr/CobLm C1 21'- 30' SOIL LOG: #4 ExGrC-MSa LOCATION: See test pit location map 30"-150' 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace <1 loam(110) - - - >20 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 132" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: It is recommended that a design infiltration rate < 20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 132" below the eXiStinq grade, Horz Depth Color Texture A 0'- 21" 10YR2/1 VGr/CobLm C1 21'- 30' t0YR4/6 ExGrC-MSa C2 30"-150' 10YR5/2 ExGr/CobCSa <2 - <75 SG - - - - >20 some stones <1 - <80 SG - - - - >20 and bpolders Soils Strata Description Soil Log #4 -/.CL %ORG CP8TR MOT IND CEM ROO 4(> FSP Q5 4p <45 15BK - - - If 2-6 2 <2 - <75 SG - - - - >20 >20 <1 - <80 SG - - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 5 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5 /2 512 01 8 SOIL LOG: #5 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 120" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 120" IMPERVIOUS/RESTRICTIVE Nearly level HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 128 in/hr for sample #3 taken at 72" below the existing grade. It is recommended that a design infiltration rate 120 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 120" below the existing rade. Horz Depth Color A 0"- 24" 10YR2/1 C1 24"- 52' 10YR416 C2 52"-148' 10YR5/2 Soils Strata Description Soil Log #5 Te#ure %CL %ORG CF STR MOT IND CEM ROO VGNCobLm 125 <10 <55 iSBK - - - ff ExGr/CobCSa <1 - <85 SG - - - - some stones ExGrCSa <1 - 75 SG - - - some stones <X> FSP 2-6 2 >20 20 >20 >20 Hoa A C1 C2 Cgm3 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 6 OF 17 PROJECT NO.: 18103 DATE: 2!7/2018 PREPARED BY: William Parnell. PE REVISED 5/25/2018 SOIL LOG: #8 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace some stones loam(110) 10YR5/2 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 112" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 112" IMPERVIOUS/RESTRICTIVE Nearly level (Till) HORIZONS: 118" 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight I Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Kest design infiltration rate calculations resulted in a calculated infiltration rate of 99 in/hr for sample #4 taken at 72" below the existing grade. It is recommended that a design infiltration rate <20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 112" below the existing rade. Deoth Color Texture 0"- 22' 1OYR211 VGr/CobLm 22- 58' 10YR4/6 E%GdCobCSa mes - Mod some stones 58"-118" 10YR5/2 ExGrCSa some stones and boulders 118"-148" 10YR5/6 E.GrLmFSa (Till) Soils Strata Description Soil Log #6 -/.CL %ORG CF STIR <25 <10 <45 1SBK <i - 85 SG MOT IND CEM ROO - - - ff <x> FSP 2-6 2 >20 >20 <1 - 75 SG - - - - >20 >20 <12 - - mes - Mod Wk - - - SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET: 7 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell. PE REVISED 5/25/2018 SOIL LOG: #7 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace 10YR2/1 loam(110) <25 4. DEPOSITION HISTORY: 5, HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 76" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 76" IMPERVIOUS/RESTRICTIVE Nearly level >15 HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING C2 Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 114 in/hr for sample #5 taken at 36" below the existing grade. It is recommended that a design infiltration rate <20 in/hr be used for proposed stormwater infiltration facilities located in the C2 horizon soils. Winter water table was present at 76" below the existing rade. Soils Strata Description Soil Log #7 Hom Death Color Texture %CL %ORG CF STR MOT IND CEM ROO <x> FSP A 0"- 18" 10YR2/1 VCobLm <25 <10 <55 1SBK - - - If 2-6 2 C1 1a"- 24" 10YR4/6 EXGTLmM- <8 - 75 SG - - - - 120 >15 FSa C2 24"-108" 10YR5/6 ExGr/CobC- <1 - <80 SG - - - - >20 >20 MSasome stones and boulders SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET:12 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #12 CEM ROO LOCATION: See test pit location map FSP 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: None Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A Greater than bottom of hole 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: Greater than bottom IMPERVIOUS/RESTRICTIVE Nearly level of hole HORIZONS: EXGrSBLnn <15 - Greater than bottom of hole SG - - 10. POTENTIAL FOR: EROSION RUNOFF PONDING 26'-123" Slight Slight I Minimal 11. SOIL STRATA DESCRIPTION: See Following chart SG - - 12. SITE PERCOLATION RATE: See FSP >20 13. FINDINGS & RECOMMENDATIONS: It is recommended that a diasngn infiltration rate < 20 m/hr be used for proposed stonnwater infiltration facilities located in the C2 and C3 horizon soils. Winter water table was not present to 162" below the existing rade. Hole cave in. Soils Strata Description Soil Log #12 Hoa Depth Calor Texture %CL %ORO CF STR MOT IND CEM ROO <X> FSP 1N A 0"- 16" 10YR2/1 VGr/CobLm <25 <10 <55 1SBK - - - 2-6 2 C1 16"- 26" 10YR3/3 EXGrSBLnn <15 - <70 SG - - - If 6-20 6 I C2 26'-123" 10YR5/2 E%GrCSa <1 - <85 SG - - - - >20 >20 C3 123'-162' 1OYR511 MSa <1 - <10 SG - - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET:13 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell. PE REVISED 5/25/2018 SOIL LOG: #13 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Oulwash GROUP: A 123" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 123" IMPERVIOUS/RESTRICTIVE Sloping FSP HORIZONS: 0"- 18" 10YR2/1 Greater than bottom of hole <25 10. POTENTIAL FOR: EROSION RUNOFF PONDING C1 Slight Slight I Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS &RECOMMENDATIONS: Grain size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 780 in/hr for sample #8 taken at 72" below the existing grade. It is recommended that a design infiltration rate < 20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 123" below the existing rade. Soils Strata Description Soil Log #13 Horz Deoth Calor Texture -/.CL %ORG CF STR MOT IND CEM Roo <X> FSP A 0"- 18" 10YR2/1 VGr/CobLm <25 <10 <45 1 S6 - - - It 26 2 C1 18'- 30° 10YR4/6 ExGrC-FSa <1 - 75 SG - - - ff >20 >20 02 30"-144" 10YR512 E%GICSe <t - <85 SG - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEETA4 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell. PE REVISED 5/25/2018 SOIL LOG: #14 IND CEM ROO LOCATION: See test pit location map FSP 1. TYPES OF TEST DONE. 2. SCS SOILS SERIES: 3, LAND FORM: None Spanaway gravelly sandy iSSK - Terrace 2-6 loam(110) Ci 2T- 36° 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A >20 65" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 65" IMPERVIOUS/RESTRICTIVE SG - Toe of Slope >20 HORIZONS: Greater than bottom of hole 10. POTENTIAL FOR: EROSION RUNOFF PONDING Slight Slight Minimal 11. SOIL STRATA DESCRIPTION. See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: it is recommended that a design infiltration rate < 20 in /hr be used for proposed stormwater infiltration facilities located in the C1 horizon soils Winter water table was resent at 65" below the existing rade. Test Rit was at the toe of slope. Soils Strata Description Soil Log #14 Hoa Deoth Color Texture -/.CL %ORG CF STR MOT IND CEM ROO <X> FSP A 0"- 20" 10YR2/1 GrLm <25 <10 <30 iSSK - - - If 2-6 2 Ci 2T- 36° 1OYR4I6 ExGrM-FSa <1 - <75 SG - - - H >20 >20 C2 36"- "' 1OYR5/2 ExGrCSa <1 - <85 SG - - - - >20 >20 some stones SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET:15 OF 17 PROJECT NO.: 18103 DATE: 2/712018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #15 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6, DEPTH OF SEASONAL HW: Glacial Oulwash GROUP: A Greater than bottom of hole 7. CURRENTWATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: Greaterthan bottom IMPERVIOUS/RESTRICTIVE Nearly level of hole HORIZONS: 0"- 14" 10YR211 Greater than bottom of hole <25 10. POTENTIAL FOR: EROSION RUNOFF PONDING C1 Slight Slight I Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Ksat design infiltration rate calculations resulted in a calculated infiltration rate of 555 inlhr for sample #7 taken at 84" below the existing grade. It is recommended that a design infiltration rate:s 20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was not resent to 144" below the existing rade. Hole cave in. Soils Strata Description Soil Log #15 Hoe Deoth Color Texture %CL %ORG OF STIR MOT IND CEM ROO <X> FSP A 0"- 14" 10YR211 VGr/CobLm <25 <10 <50 1SBK - - - If 2-6 2 C1 14"- 27' 10YR4/6 ExGrC-FSa <1 - <80 SG - - - If >20 >20 C2 27"-144" 10YR5/2 ExGrCSa q - <90 SG - - - - >20 >20 SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET:16 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 REVISED 5/25/2018 PREPARED BY: William Parnell. PE SOIL LOG: #16 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2, SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spanaway gravelly sandy Terrace 0% 12" loam(110) VGrLm 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 97" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS: DEPTH: 97' IMPERVIOUS/RESTRICTIVE Toe of Slope SG - HORIZONS: >20 120 Greater than bottom of hole 21'-120" 10. POTENTIAL FOR: EROSION RUNOFF PONDING SG - Slight Slight Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Ksat design inFllfration rate calculations resulted In a calculated infiltration rate of 1253 in/hr for sample #8 taken at 60' below the existing grade. It is recommended that a design infiltration rate < 20 iNhr be used for proposed stormwater Infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 97" below the existin rade. Test it was at the toe of slo e. Soils Strata Description Soil Log #16 Hoa Deoth Color Texture -/.CL %ORG CF STR MOT IND CEM ROO O(> FSP A 0% 12" 10YR&1 VGrLm <25 <10 <55 1SBK - - - If 2-8 2 Ci 12"- 21' 10YR418 ExGrc-FSa <1 - <80 SG - - - If >20 120 C2 21'-120" 10YR5/2 ExGrCSa <t - <90 SG - - - - >20 >20 some stones SOIL EVALUATION REPORT FORM 2: SOIL LOG INFORMATION PROJECT TITLE: NPR Holdings LLC SHEET:17 OF 17 PROJECT NO.: 18103 DATE: 2/7/2018 PREPARED BY: William Parnell, PE REVISED 5/25/2018 SOIL LOG: #17 LOCATION: See test pit location map 1. TYPES OF TEST DONE: 2. SCS SOILS SERIES: 3. LAND FORM: Grain Size Analysis Test Spaneway gravelly sandy Terrace loam(110) 4. DEPOSITION HISTORY: 5. HYDROLOGIC SOIL 6. DEPTH OF SEASONAL HW: Glacial Outwash GROUP: A 106" 7. CURRENT WATER 8. DEPTH TO 9. MISCELLANEOUS. DEPTH: 106" IMPERVIOUS/RESTRICTIVE Toe of Slope FSP HORIZONS: 0°- 20" 10YR211 Greater than bottom of hole <25 10. POTENTIAL FOR: EROSION RUNOFF PONDING cl Slight Slight 1 Minimal 11. SOIL STRATA DESCRIPTION: See Following chart 12. SITE PERCOLATION RATE: See FSP 13. FINDINGS & RECOMMENDATIONS: Grain size analysis and Vast design infiltration rate resulted in a calculated infiltration rate of 410 in/hr for sample #9 taken at 66" below the calculations existing grade. It is recommended that a design infiltration rate < 20 in/hr be used for proposed stormwater infiltration facilities located in the C1 and C2 horizon soils. Winter water table was present at 106" below the existing rade. Test oit was at the toe of slo . Soils Strata Description Soil Log #17 Hoa Depth Color TeA.re %CL %ORG CF STIR MOT IND CEM ROO <X> FSP A 0°- 20" 10YR211 VGr/CobLm <25 <10 <55 iSBK - - - ff 2-6 2 cl 20"- 38" 10YR416 ExGrC-FSa <i - <85 SG - - - ff >20 >20 C2 38'-122" 1OYR512 ExGr/CabCSa <1 - <85 SG - - - - >20 >20 some stones Abbreviations Textural Class Texture Structure STR 1st Letter Abundance2nd Grades of Structure Cobbled - Cob Granular - Gr -3 Stone - St Block - Blky -Strong Moderate - 2 Gravel) - Gr Plat - PI Weak - 1 Sand - Sa Massive - Mas Loam - Lm Sin le Grained -SG Silty - Si Sub -Angular Block - SBK Clayey -Cl Coarse - C Very - V Extreme) - Ex Fine - F Medium - M Induration & Cementation IND CEM Weak -Wk Moderate - Mod Strong Str Mottles MOT 1st Letter Abundance2nd 1 Letter Abundance 1st Number Size 2nd Letter Contrast Few - F Fine - 1 Faint - F Common - C Medium - 2 Distinct - D Man - M I Coarse -3 Prominent - P Roots (ROO) 1st Letter Abundance2nd Letter Size Few -f Fine -f Common - c Medium - m Man - m Coarse - c <X> - Generalized range of infiltration rates from SCS soil survey (<X>) FSP - Estimated Design Field Saturated Percolation rate based on horizon specific factors and specific test results. Did= 0.7 D6o = 7.0 Deo= 19.0 frees = 0.004 logto(Ksat) = -1.57 + 1.90Dio + 0.015D6o - 0.013D90 - 2.08frnes logio(Ksat) = -1.57 + 1.90(0.7) + 0.015(7.0) - 0.013(19.0) - 2.08(0.004) Ksnt = 0.4071 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 577 in/hr Design Infiltration Rate Calculation • I i [design = Ksat mmai X CFT Ksaustw = 577 in/hr CFT = CF, x CFt x CF. CFT=1.0x 0.4x 0.9 CFT= 0.36 [design = 577 X 0.36 laseign = 208 in/hr For stormwater facility design purposes, use an [design < 20 in/hr. Dto= 0.8 Den= 7.0 Deo = 16.5 taus = 0.005 logm(Ksat) = -1.57 + 1.90Dia + 0.015Dso - 0.013Doo - 2.08fr,.. logto(Ksat) = -1.57 + 1.90(0.8) + 0.015(7.0) - 0.013(16.5) - 2.08(0.005) Ksat = 0.6762 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 958 in/hr Desian Infiltrtion Rat Calcultion' laesi, = Ksat me X CFr Ksaolmem = 958 Whir CFr = CF. x CR x CFm CFT=1.0x0.4x0.9 CFT= 0.36 ld.sIp = 958 X 0.36 Idesiaa = 345 in/hr For stormwater facility design purposes, use an lasMy. < 20 in/hr Did= 0.58 Deo = 6.5 Deo= 17.0 fines = 0.004 logio(Ksat) = -1.57 + 1 MDio + 0.015D60 - 0.013Dso - 2.08fanes logio(Ksat) = -1.57 + 1.90(0.58) + 0.015(6.5) - 0.013(17.0) - 2.08(0.004) Ksat = 0.2513 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 356 in/hr Desian Infiltration Rate Calculation : Idasian laesign = Ksat inmai X CFi Ksai maai = 356 in/hr CFr=CF.x CFtx CF. CF.=1.0x0.4x 0.9 CFr= 0.36 laesign = 356 X 0.36 [design = 128 in/hr For stormwater facility design purposes, use an laesign < 20 in/hr Dto= 0.52 Deo = 9.5 Dso= 20.0 fines = 0.007 logio(Ksat) = -1.57 + 1.90Dto + 0.015D6o - 0.013Dso - 2.08frnes logto(Ksat) = -1.57 + 1.90(0.52) + 0.015(9.5) - 0.013(20.0) - 2.08(0.007) Kw = 0.1932 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 274 in/hr Desian Infiltration Rate Calculation : Idasion Ideslgn = Ksat intow X CFT Ksat mm = 274 in/hr CFT = CFv x ON x CFm CFT =1.0x0.4x 0.9 CFr= 0.36 WW, = 274 X 0.36 laesign = 99 in/hr For stormwater facility design purposes, use an Idasign < 20 in/hr Dig= 0.60 D6o = 0.7 Dgo= 17.0 fines = 0.005 logia(Ksan) = -1.57 + 1.90Dio + 0.015D6a - 0.013Dso - 2.08fnnes logio(Ksat) = -1.57 + 1.90(0.60) + 0.015(0.7) - 0.013(17.0) - 2.08(0.005) Kest = 0.2234 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 317 in/hr n sian Infiltration Rate Calculation , la i [design = Kset imdsi X CFr Ksaunmsi = 317 in/hr CFT = CFs x CFt x CF. CFr=1.0x0.4x 0.9 CFT= 0.36 Idesign = 317 X 0.36 Idesign = 114 in/hr For stormwater facility design purposes, use an [design < 20 in/hr Dto= 1.0 Deo = 6.7 Deo= 17.5 fnnes = 0.009 log to(Ksat) = -1.57 + 1.90Dto + 0.015Dea - 0.013Dgo - 2.08fdnes logto(Ksat) = -1.57 + 1.90(1.0) + 0.015(6.7) - 0.013(17.5) - 2.08(0.009) Ksat = 1.5286 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 2166 in/hr Infiltration Rate Calculatio Idesign = Ksat mi6atX CFr Ksatmmai = 2166 in/hr CFr = CFv x CFt x CF. CFr=1.0x0.4x 0.9 CFr = 0.36 Ideslgn = 2166 X 0.36 leesign = 780 in/hr For stormwater facility design purposes, use an Idesign < 20 inlhr Dig= 0.9 D6o= 10.0 Dso= 18.5 fnnes = 0.006 logio(Ksat) = -1.57 + 1.90Dio + 0.015Deo - 0.013Dgo - 2.08fdnes log o(K m) = -1.57 + 1.90(0.9) + 0.015(10.0) - 0.013(18.5) - 2.08(0.006) Kiat = 1.089 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 1543 in/hr Desian Infittration Rate Calculation : ggaugn Ideeign = Kut initial X CFr Keaunmai = 1543 in/hr CF=CFsx CFtx CF. CFr=1.0x0.4x 0.9 CFr= 0.36 [design = 1543 X 0.36 _ [design = 555 in/hr For stormwater facility design purposes, use an Idesign < 20 in/hr Dm= 1.1 No = 6.9 Dso= 16.5 fines = 0.009 logio(Ksat) = -1.57 + 1.90Dm + 0,015Deg - 0.013D90 - 2.08fnnes logtg(Ksat) = -1.57 + 1.90(1.1) + 0.015(6.9) - 0.013(16.5) - 2.08(0.009) Kw = 2.456 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 3481 in/hr Desian Infiltration Rate Calculation , Iain' [design = Kat maw X CFr Keaunteai = 3481 in/hr CFr = CFe x CFt x CFm CFr=1.0x 0.4x 0.9 CFr= 0.36 [design = 3481 X 0.36 Idesign = 1253 in/hr For stormwater facility design purposes, use an Idesign < 20 in/hr Dic= 0.85 Deo= 5.5 Dm= 16.0 fnnea = 0.007 logm(Ksat) = -1.57 + 1.90Dio + 0.015Deo - 0.013Dsa - 2.08fgnes logio(K:at) = -1.57 + 1.90(0.85) + 0.015(5.5) - 0.013(16.0) - 2.08(0.007) Ksat = 0.8034 cm/s x 0.3937 in/cm x 60s/min x 60 min/hr = 1139 in/hr Desian Infiltration Rate Calculation : laastnn [design = Keat initial X CFr Ksaumuai = 1139 in/hr CFr = CFv x Ch x CF. CFr=1.0 x0.4x 0.9 CFr= 0.36 Idesign = 1139 X 0.36 [design = 410 in/hr For stormwater facility design purposes, use an laestgn < 20 in/hr SOIL Loi TES P,T lry-anov MAP 0- SOIL L06i \ AA I l I� r _..- i Ely#Jbr , � �• + I til > r f f l v I ' rl r PART 9 — OTHER PERMITS ,. The following is a list of regulatory permits needed for this project and copies are attached if available. SEPA Review — Pending Determination Grading and Drainage — Pending Final Drainage and Grading Plans ' Building Permits — Pending Design and Permitting 18025 Drainage Report 9-1 PART 10 — OPERATION AND MAINTENANCE MANUAL A final Operation and Maintenance Manual will be prepared during the final design of the drainage plan. It will follow the WSDOE guidelines. 18025 Drainage Report 10-1 + PART 11 —BOND QUANTITIES/FINANCIAL RESPONSIBILITY -. Facility agreements and financial guarantees when required will be reviewed by the applicant and executed at the appropriate time determined by the reviewing agency. 18025 Drainage Report 11-1 PART 12 — GRADING AND DRAINAGE PLANS The half size drawing of the site civil grading and drainage plans are included on the following pages. 18025 Drainage Report 12-1