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04-0180 Preliminary Drainage Report 11042004
1 1 ~1 1 1 t 1 1 YEI~l~I C®1VIlVII.TNI'I'Y SCI®®I..S YELIVI ~[TNI®I2 ~IIGII SCI-I®®I, Preliminary Drainage and Erosion Control Report Proponent Yelm Community School P O Box 476 Yehn, WA 98597 (360) 458-6128 Prepazed By Robert E Tauscher, P E Jerome W Mornssette & Associates Inc , P S 1700 Cooper Point Road SW, #B2 Olympia, WA 98502 Phone (360) 352-9456 Fax (360) 352-9990 Submrtted November 2004 Received NOV 4 2004 1 1 1 1 1 YEI~M C®MMIJNITY SCSI®®I,S YEI~M JLTIVI®I~ I-IIG~I SCI-I®OI, Prehmtnary Drainage and Erosion Control Report Proponent Yelm Commumty School P O Box 476 Yelm, WA 98597 (360) 458-6128 Prepared By Robert E Tauscher, P E Jerome W Momssette & Associates Inc , P S 1700 Cooper Point Road SW, #B2 Olympia, WA 98502 Phone (360) 352-9456 Fax (360) 352-9990 Submitted November 2004 1 TABLE OF CONTENTS I DRAINAGE REPORT Section 1 -Protect Descrption ' Section 2 -Existing Conditions Section 3 -Infiltration Rate/Soils Report Section 4 -Wells ' Section 5 -Fuel Tanks Section 6 -Sub-balm Descnption Section 7 - 100 Yeaz Flood Section 8 -Aesthetic Considerations Section 9 -Facility Sizing and Downstream Analysis Section 10 -Covenants, Dedications, and Easements Section 11 -Articles of Incorporation ' II EROSION CONTROL REPORT Section 1 -Sequence ' Section 2 -Trapping Sedunent Section 3 -Permanent Erosion Control Section 4 - Geotechmcal Report ' Section 5 -Inspection Section 6 -Control of Pollutants Other than Sediment ' III APPENDIX A Soils Report B Calculations and Hydraulic Analysis ' C Commercial Stormwater Facilities Maintenance Agreement D Thurston Region Stormwater Fac~hties Summary Form E Basin Map C Site Plan G Engineer's Estimate H Adjacent Wells Yelm Community Schools -Junior High School Drainage and Eros~oa Control Report JWM&A # 03157 1 1 2 2 2 3 3 3 3 7 8 8 9 9 9 9 PROJECT ENGINEER'S CERTIFICATE 1 "I HEREBY CERTIFY THAT THIS PROJECT, YELM 3iJNIOR HIGH SCHOOL, YELM COMMUNITY SCHOOLS, YELM, WASHINGTON HAS BEEN PREPARED BY ME OR UNDER MY SUPERVISION AND MEETS MINIMiJM STANDARDS OF CITY OF YELM 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 BY ME " 4~,~woF wasy~ cCy~' ~e o ~ p Robert E Tauscher, P E ~ = x b Jerome W Momssette & Associates Inc , P S LC W3TJ39 ~O„C R~G1cTEFF'O ~S~ONA*~~~ Et PIRES ~i2 (~7 (~(~ 1 Yehn Community Schools - Jwnor High School Drainage and Erosion Control Report JWM&A # 03157 i ' YELM COMMUNITY SCHOOLS ' YELM JUNIOR HIGH SCHOOL YELM, WASHINGTON DRAINAGE AND EROSION CONTROL REPORT PART I DRAINAGE REPORT This report has been prepazed as part of the regwrements for the Stte Plan Review for the subJect site and in accordance with the "Stormwater Management Manual for the Puget Sound Basin, " 1992 and the City of Yehn requirements Section 1-Protect Descnphon ' l as The tumor Htgh School site consists of 30 7 Acres located on the same parce the Mtle Pond Elementary School Only a 21 07 acre portion of the pazcel will be ' disturbed The site ties on the southeast side of SR 510 (Yehn Avenue) m Yelm, Washington, m the Southeast quarter (SE %<) of the Northwest quarter (NE '/4) of Section twenty five (25), Township seventeen (17) North, Range one (1) East ' The assessors pazcel number is 217225140100 The site is relatively flat on the eastern two thirds of the parcel and the western ' third drops approximately nine feet The proposed main access well be from Carter Street SE, a fire lane will be from 107u' Avenue SE accessin g ' The overall project will involve the construction of a new building, parking lot, and sports fields The stormwater system from the new school will be collect and convey to a treatment device and eventually into an infiltration pond for disposal The design infiltration rate is 10 mches/hour The existing Mill Pond School ' storm water currently is treated by a bio-filtration Swale, which will be slightly moved to accommodate the fire lane The stoimwater from the Mill Pond School currently is directed to a pond The Mill Pond School stormwater will be redirected to a new underground infiltration gallery for disposal ' Roof runoff from the new building and will be diverted to the pond The stotmwater system has been designed to the standards of the "Stormwater Management Manual for the Puget Sound Basin," 1992 The treatment device and Swale aze sized for the 6-Month/24 Hour Design Event and the infiltration pond and gallery are sized for the 100 Year/24 Hour Design Event Section 2 - Ex-shng Condrtwns. 1 Yehn Community Schools -Junior High School Drainage and Erosion Control Report t JWM&A # 03157 1 1 The site has a gentle slope towards the west with an elevation change from 370 ' feet along Mill Pond Road SE to 348 along the west corner property tine Section 3 -Infiltration Rates/Snits Report ' Sods on the site aze listed in the Soil Conservation Service's Soil Survey of Thurston County Washington as Spanoway gravelly sandy loam Typical soils are a dark grayish brown and gravelly sandy loam neaz the surface with dazk yellowish brown very gravelly sandy loam occturntg wttlun two feet of surface (See Soils Report and logs m Appendix A) The soil mapping from this soil survey indicates that the predominant soil group at flits site is "B" An evaluation of the surfictal soils was conducted and a copy of the soils ' mfonnation is located m Appendix A The soils report confirms the soil survey mappmg The soil logs typically indicate sandy gravel to 36-96" The infiltration rate measured in a falling head test performed at 48 inches below the existing ' surface is > 60 inches per hour A descnpt~on of the falling head infiltration test device used to perform the percolation test and infiltration tests results aze found in Attachment A Field percolation tests performed yielded a percolation rate range between three holes of 30 in/hr to 60 in/hr Incorporating a factor of safety greater than 2, the ' estimated percolation rate used for design is 10 inches per hour ' Section 4 -Wells and Septrc Systems: A search of Department of Ecology web site was performed to identify nearby wells (see Appendix H) The search yielded 4 locations Location 1 fisted 3 well logs, only two of which are m proxirntty to the site and aze fisted as lA and 1 B There is only one well log at location 2 and rt is fisted as 2A There are 4 well logs at location 3, listed as 3A, 3B and 3C Well log 3D could not be located from the ' information on the well log Location 4 was listed as a resource protection log only The existing Mill Pond School is connected to the City STEP system for disposal of waste products The proposal new school will also be connected to the City of ' Yehn STEP sewer system Sectron 5 -Fuel Tanks ' Based on information from the current property owner, numerous site inspections, and the expressed intentions of the owner, it is evident that there are no known ' fuel tanks existing on the property No fuel tanks will be brought onto the property during development Yehn Community Schools -Junior High School Drainage and Erosion Control Report JWM&A # 03157 Section 6 -Sub-basin Descnphon 1 The improved portion of the site has been divided into two basin tnbutary to the separate infiltration systems Protect site runoff will be routed through either bio- filtration swales or treatment devices for treatment an then to infiltration gallenes for disposal A prehmmazy basin analysis was conducted for this project and can be located m f th d l A E is p ppen ix an o Section 7 -100 Year Flood The protect does not contain or abut a stream and is not in a flood zone th C ti 8 A t d h S ons- era ec on - es e ic ons All disturbed areas will be vegetated or landscaped The stormwater facilities consist of a treatment devices, swales, catch basins and conveyance piping to collect runoff and convey to underground rnfiltration gallenes The pazking lot 1 section meets the city of Yelm standards Consequently, the overall aesthetic affect of the stonnwater facilities on this site will be consistent with other facilities within the vicinity and should not detract from sun•oundmg azeas Section 9 - Facilrty Sizing and Downstream Analysis The impacts of the proposed development on stormwater runoff have been analyzed m accordance with the procedure descnbed m the "Stormwater Management Manual for the Puget Sound Basin," 1992 All stonnwater conveyance and detention systems were designed for the 100 Yeaz /24 Hour Design Event as outlined in the above listed Manual The hydraulic analysis for the on-site stormwater facilities can be found m Appendix B 1 The evaluation performed includes the pond storage and HYDRA analyses (HYDRA Version 5 85, July 1994) Copies of the HYDRA Input and Output files ' and table summanzing the site azea and pond volume chazactenstics aze included m Appendix B ' POST DEVELOPMENT SITE CHARACTERISTICS Total Disturbed Area 30 7 Acres i Pass-Through Drainage Area 0 0 Acres Zone 1 -New tumor HS 3 Yelm Community Schools -Junior High School Drnmage and Erosion Control Report JWM&A # 03157 Area Tributary to Facrhty Including Offsite {Acres) 11 68 Acres Total Onsrte Area Tributary to Facility (Acres) 11 68 Acres ' Design Impervious Area Tributary to Facility (Acres) 6 22 Acres Design Landscaped Area Tributary to Facility (Acres) S 46 Acres Area not Tributary to the Facrhty (Acres) 9 39 Acres ' Basin Area (Acres) 21 07 Acres ' Zone 2 -Mill Pond Elementary Total Area Tributary to Facility Including Offsrte (Acres) 9 63 Acres Total Onsrte Area Tributary to Facrhty (Acres) 9 63 Acres Design Impervious Area Tributary to Facrhty (Acres) 4 62 Acres Design Landscaped Area Tributary to Facrhty (Acres) 5 Ol Acres Design Total Tributary Area to Facrhty (Acres) 9 63 Acres SCS Data Hydrologic Sorl Group "B" Curve Numbers ' Impervious Areas 98 Pervious Areas 68 SYSTEM MINIMUM REQUIREMENTS Zone 1 -New Junior HS Total Area (Acres) Required Volume per HYDRA Infiltration Rate with 525 sf Bottom 2107 Acres 63,122 CF 7 41 CFS Zone 2 -Mill Pond Elementary Area Tributary to Facility Including Offsrte (Acres) Required Volume per HYDRA Infiltration Rate with 8,175 sf Bottom 9 63 Acres 28,402 CF 1 81 CFS System Performance New Junior High School Within the sub}ect site, stonnwater from pazlung lots will be routed to a treatment device and into infiltration galleries Runoff from the new building will be directed into the stonnwater system Mill Pond Elementary School Within the sub}ect site, stormwater from parking lots wtll be routed to the bio- filtration Swale and into infiltration gallery Runoff from the exisrtng building is directed into the stonnwater system Zone 1 -New Junior High School -Based on the HYDRA analyses performed for the 24 hour - 100 Yeaz Event, the peak flow into the stonnwater pond will be Yelm Community Schools -Junior High School Drainage and Erosion Control Report JWM&A # 03157 4 t 19 50 CFS The maximum storage volume expected in the pond per HYDRA ' 63,122 CF The design infiltration rate is 7 41 CFS with the gallery bottom of 32,000 SF and 64,000 CF of storage volume provided in the gallery ' Zone 2 -Mill Pond Elemenatry -Based on the HYDRA analyses performed for the 24 Hour - 100 Yeaz Event, the peak flow into the stormwater gallery will be 6 28 CFS The maximum volume expected in the gallery per HYDRA is 28,402 ' CF The design mfiltratron rate is 1 81 CFS wtih the gallery bottom of 8,175 SF and 28,413 CF of storage volume provided m the gallery Downstream Analysis There are no downstream impacts due to all stonnwater being detained and infiltrated on site Section 10 -Covenants, Dedications, >Easements. ' Operation and maintenance of the stormwater gallenes, catch basins, and piping will be the responsrbrhty of the property owner The facilities will require routine ' maintenance and a draft Cornmercial/Industnal stormwater facilities maintenance agreement prepazed for this proposal is located m Appendix D Section 11 -Articles of Incorporation. The parcel is pnvately owned, Articles of Incorporation aze not required for the ' proposal lJ t Yelm Community Schools -Junior High School Drainage and Erosion Control Report t JWM&A # 03157 1 t PART II EROSION CONTROL REPORT ' Section 1 -Sequence. 1 The following is the construction sequence for construction of the pazking lots and ponds I Install silt fences where shown on the improvement plans 2 Rough grade pazking lot areas 4 Install stonnwater pond and structures 5 Fuush grade, topsoil, fertilize, and seed disturbed areas 6 Mulch landscaped areas if constmction is performed between October 15 ' and April 15 7 Once disturbed surfaces have developed suitable groundcover, remove perimeter silt fences S 2 ection -Trapping Sediment The proposed grading of the site, as well as the construction of the items fisted below, will mitigate against any mayor diversion of stormwater runoff by maintaining natural drainage patterns The structural components of the erosion control plan will work m combination with temporary and permanent soil stabilization efforts to minimize the amount of sedunent-laden runoff entering adjacent properties and the existing on-site wetlands 1 Measures Taken to Control Sedunent t Filter Fabric Silt Fences located down-slope of all earthwork that may pose a potential of releasing sediment-laden water to the ofF ' site Permanent sediment trapping will be accomplished with sediment traps if necessary, where vegetation and pond configuration will cause soil particles to drop out of solution as the stormwater passes through the area All entrances will be paved and the site is surrounded by paved city streets If a substantial amount of soil is being deposited on adJacent streets due to truck traffic, the road will immediately be cleaned of all debris and further preventative measures will betaken to ensure the problem ceases, such as establishing a tare wash down area t All of the above features of the Erosion and Sednnentation Control Plan, if installed and periodically maintained, are expected to minimize the potential for Yehn Community Schools -Tumor High School Drainage and Erosion Control Report t IWM&A # 03157 1 ' PART IL EROSION CONTROL REPORT Section 1 -Sequence The following is the construction sequence for construction of the pazking lots and ponds 1 1 Install silt fences where shown on the improvement plans 2 Rough grade parking lot azeas 4 Install storinwater pond and structures 5 Fumsh grade, topsoil, fertilize, and seed disturbed areas 6 Mulch landscaped azeas if construction is performed between October 15 ' and Aprl 15 7 Once disturbed surfaces have developed sortable groundcover, remove perimeter silt fences ' Section 2 -Trapping Sediment ' The proposed grading of the site, as well as the construction of the items fisted below, will mitigate against any mayor diversion of stonnwater runoff by ' mamtairung natural drainage patterns The structural components of the erosion control plan will work m combination with temporary and permanent soil stabilization efforts to mimmize the amount of sediment-laden runoff entering adjacent properties and the existing on-site wetlands Measures Taken to Control Sediment ' F l F b S l F i ter ric i a t ences located down-slope of all earthwork that may pose a potential of releasing sediment-laden water to the off- ' site Permanent sedunent trapping will be accomplished with sedunent traps id necessary, where vegetation and pond co>~guration will cause soil particles to drop out of solution as the stormwater passes through the azea All entrances are paved and site is surrounded by paved city streets If a substantial amount of soil is being deposited on adjacent streets due to truck traffic, the road will immediately be cleaned of all debrs and further preventative measures will be taken to ensure the problem ceases, such as establishing a tire wash down azea All of the above features of the Erosion and Sedimentation Control Plan, if installed and perodically maintained, aze expected to minunize the potential for Yelm CommumTy Schools -Junior High School 6 Drainage and Erosion Control Report 1 JWM&A # 03157 sediment-laden runoff escaping the site and entering the downstream environment ' during and after the construction of the protect Section 3 -Permanent Erosion Control- , The following measures wtll be taken for soil stabilization to minimize the amount of sediment-laden runoff entering adjacent properties and the existing on- ' site wetlands • Stabilization of cut and fill areas with hydro seeding and, if ' necessary, chopped hay mulching (or~ute matting) Permanent erosion control on this site will be accomplished through the development of landscaping or grass groundcover on all unpaved disturbed areas Section 4 - Geotechnical Report. ' There are no other incipiently unstable stonnwater related conditions within the ' project site, hence, no other additional soil investigations or analyses are planned Section 5 - Inspection- ' The construction of stormwater facilities on the subject site will be monitored by the Owner and the Owner's representative m accordance with the requirements of ' the Drainage Manual The following is the recommended inspection sequence for the construction of ' stonnwater facilities described above 1 At completion of rough grading ' 2 At completion of paving, fine grading, fertilizing, seeding, and mulching 3 At complerion of the galleries ' Section 6 -Control of Pollutants Other Than Sediments. As the subject site development will consist of commercial use, rt will most likely ' not involve the storage or use ofnon-sediment pollutants on thus site Temporary pollutant sources, such as cement truck wash-down waste, fuel spillage during equipment refueling, and construction waste materials may develop for short periods during the construction of the parking lots and stonriwater facilities Care will be taken to inimmize the adverse impacts of these conditions Activities ' such as concrete truck wash-down and equipment refueling will be carried out m the vicinity of construction, at least 25 feet from the stormwater facilities Yelm Community Schools -Junior High School 7 Drainage and Erosion Control Report JWM&A # 03157 Constructron material stockpile areas should be limited to the munedrate vtctmty of the dwellings being constructed Bulk petrochemical storage, m the form of gasoline, fuel, oil, lubricants, and other such hazazdous fluids will not be pernutted on this site Yelm Community Schools -Junior High School Drainage and Eroswn Control Report J W M&A # 03 ] 57 1 lJ ~~ 1 1 1 [~ 1 S®Ills Rep®rt 1 Thurston County Washington 'Included areas make up about 10 percent of the total acreage Permeability is moderately rapid in the Spana soil Available water capacity is moderate Effective rooting depth is 20 to 40 inches A seasonal high water table is 'at a depth of about 12 to 36 inches from November to April Runoff is slow and the hazard of water erosion is slight Most areas are used as hayland and pasture This 'unit is suited to hay and pasture The main limitations are the seasonal high water table and the moderate vailable water capacity Proper stocking rates, pasture ~otaUon, and restricted grazing during wet periods help o keep the pasture in good condition and protect the soil from erosion Rotation grazing helps to maintain the uality of forage Periodic mowing helps to maintain niform growth discourages selective grazing, and controls weeds In most years irrigation is needed for awmum production Spunkier irrigation is the best ~nethod of applying water The amount of water applied should be sufficient to wet the root zone but small enough to mmim¢e the leaching of plant nutrients A few areas are used as woodland On the basis of a 00-year site curve, the estimated site index for Douglas fu is 144 On the basis of a 50-year site curve is 110 The estimated growth rate of an unmanaged ~ven-aged stand of Douglas fir is 150 cubic feet per acre per year at 60 years of age The main limitation affecting the harvesting of timber the muddiness caused by seasonal wetness Use of heeled and tracked equipment when the soil is wet results in ruts and soil compaction Unsurtaced roads ~nd skid trails are soft and can be impassable when et Logging roads require suitable surfacing material for year round use Rounded pebbles and cobbles for ad construction are readily available on this unit The ~easonal high water table limits the use of equipment to dry periods Disturbance of the protective layer of duff an be minimized by the careful use of wheeled and ~acked egwpment Seedling establishment is the main concern in the production of timber Reforestation can be ccomplished by planting Douglas fir seedlings If the tand includes seed trees natural reforestation by red alder occurs periodically in cutover areas The seasonal ~gh water table inhibits root respiration and thus results some seedling mortality When openings are made in the canopy invading brushy plants can prevent the stablishment of planted Douglas fir seedlings Common forest understory plants are cascade regon grape, salal vine maple, western brackenfern and Oregon white oak 89 This map unit is in capability subclass Illw 110-Spanaway gravelly sandy loam, 0 to 3 percent slopes This very deep, somewhat excessively drained soil is on terraces It formed in glacial outwash and volcanic ash The native vegetation is mainly grasses, ferns and a few conifers Elevation is 100 to 400 feet The average annual precipitation is 45 to 55 inches, the average annual air temperature is about 51 degrees F, and the average frost-tree period is 150 to 200 days Typically the surface layer is black gravelly sandy loam about 15 inches thick The subsoil is dark yellowish brown very gravelly loam about 5 inches thick The substratum to a depth of 60 inches or more is dark yellowish brown extremely gravelly sand Included in this unit are small areas of Alderwood soils on till plains Everett, Indianola and Nisqually soils on outwash terraces, and Spana soils in depressions Also included are small areas of Spanaway soils that have a stony sandy loam surface layer and small areas of Spanaway gravelly sandy loam that have slopes of 3 to 15 percent Included areas make up about 20 percent of the total acreage Permeability is moderately rapid in the subsoil of the Spanaway soil and very rapid in the substratum Available water capacity is low Effective rooting depth is 60 inches or more Runoff is slow and the hazard of water erosion is slight This unit is used mainly as hayland pasture or cropland, as a site for homes, or as a source of gravel It is also used as woodland The main limitation affecting hay and pasture is the low available water capacity Proper grazing practices weed control and fertilizer are needed to ensure maximum quality of forage Rotation grazing helps to maintain the quality of forage Periodic mowing helps to maintain uniform growth discourages selective grazing, and controls weeds Animal manure can be applied periodically during the growing season Areas that receive heavy applications should be harrowed at least once a year In summer, irrigation is needed for maximum production of most forage crops Sprinkler irrigation is the best method of applying water The amount of water applied should be sufficient to wet the root zone but small enough to minimize the leaching of plant nutrients This unit is suited to crops Wheat, oats, strawberries, raspberries, blackberries, and sweet corn are commonly grown The main limitation is the low available water capacity In summer, irrigation is needed for maximum production of most crops so Sprinklers can be used but a slow application rate is needed to minimize runoff The amount of water applied should be sufficient to wet the root zone but small enough to minimize the leaching of plant nutrients The application rate should be adtusted to the available water capacity the water intake rate, and the needs of the crop Animal manure can be applied periodically during the growing season Areas that receive heavy applications should be harrowed at least once a year This unit is well suited to homesites Pebbles and cobbles should be removed particularly in areas used for lawns In summer irngaUon is needed for lawn grasses shrubs vines, shade trees, and ornamental trees Mulch fertilizer and irrigation are needed to establish lawn grasses and other small seeded plants The main limitahon affecting septic lank absorption fields is a poor filtering capacity If the density of housing is moderate or high community sewage systems are needed to prevent the contamination of water supplies caused by seepage from onsite sewage disposal systems Cutbanks are not stable and are subtect to sloughing Douglas fir is the main woodland speaes on this unit Among the trees of limited extent are Oregon white oak, lodgepole pine and red alder Douglas fir and Scotch pine are grown on Christmas tree plantations On the basis of a 100-year site curve, the mean site index for Douglas-fir is 140 On the basis of a 50-year site curve, it is 108 The highest average growth rate of an unmanaged, even-aged stand of Douglas-fir is 145 cubic feet per acre per year at 65 years of age This soil is suited to year-round logging Unsurfaced roads and skid trails are slippery when wet Logging roads require suitable surfacing material for year round use Rounded pebbles and cobbles for road construction are readily available on this unit Disturbance of the protective layer of duff can be minimized by the careful use of wheeled and tracked egwpment Seedling establishment and seedling mortality are the main concerns in the production of timber Reforestation can be accomplished by planting Douglas-fir seedlings If the stand includes seed trees natural reforestation by Douglas fir Oregon white oak and lodgepole pine occurs periodically in cutover areas Droughtiness in the surface layer reduces the seedling survival rate When openings are made in the canopy, invading brushy plants can delay the establishment of planted Douglas- fir seedlings Common forest understory plants are cascade Oregon grape, salal, western brackenfern, western swordfern, Indian plum, and Scotch-broom Soil Survey This map unit is in capability subclass IVs 111-Spanaway gravelly sandy loam, 3 to 15 percent slopes This very deep, somewhat excessively drained soil is on terraces It formed in glaaal outwash and volcanic ash The native vegetation is mainly grasses, ferns, and a few conifers Elevation is 100 to 400 feet The average annual precipitation is 45 to 55 inches, the average annual air temperature is about 51 degrees F, and the average frost free period is 150 to 200 days Typically, the surface layer is black gravelly sandy loam about 15 inches thick The subsoil is dark yellowish brown very gravelly sandy loam about 5 inches thick The substratum to a depth of 60 inches or more is dark yellowish brown extremely gravelly sand Included in this unit are small areas of Alderwood soils on till plains and Everett Indianola, and Nisqually soils on terraces Also included are small areas ofi Spanaway soils that have a stony sandy loam surface layer and small areas of Spanaway gravelly sandy loam that have slopes of 0 to 3 percent Included areas make up about 20 percent of the total acreage Permeability is moderately rapid in the subsoil of the Spanaway soil and very rapid in the substratum Available water capacity is low Effective rooting depth is 60 inches or more Runoff is slow, and the hazard of water erosion is slight This unit is used mainly as hayland or pasture, as a site for homes, or as a source of gravel It is also used as woodland The main limitation affecting hay and pasture is the low available water capacty during the growing season Proper grazing practices, weed control, and fertilizer are needed to ensure maximum quality of forage Rotation grazing helps to maintain the quality of forage Periodic mowing helps to maintain uniform growth, discourages selective grazing, and controls weeds Animal manure can be applied periodically dunng the growing season Areas that receive heavy applications should be harrowed at least once a year In summer, irrigation is needed for maximum production of most forage crops Sprinkler irrigation is the best method of applying water The amount of water applied should be sufficient to wet the root zone but small enough to minimize the leaching of plant nutrients This unit is suited to homesites The main limitation is the slope Cutbanks are not stable and are subtect to sloughing A plant cover can be established and maintained through proper fertilizing, seeding, mulching, and shaping of the slopes Pebbles and cobbles should be removed, particularly in areas used for lawns In 1 'i58 IJ lJ t ll Spanaway Series The Spanaway series consists of very deep somewhat excessively drained soils on terraces These sons formed in glacial outwash and volcanic ash Slope is 0 to 15 percent Elevation is 100 to 400 feet The average annual preapdation is 40 to 55 inches the average annual air temperature is about 51 degrees F and the average frost free season is 150 to 200 days These soils are sandy skeletal mixed mesic Andic Xerumbrepts Typical pedon of Spanaway gravelly sandy loam 0 to 3 percent slopes 4 miles southeast of Lacey about 250 feet west and 400 feet south of the northeast corner of sec 25 T 36 N R 1 W A-0 to 15 inches black (10YR 2/1) gravelly sandy loam very dark grayish brown (10YR 3/2) dry weak fine granular structure loose, very friable nonshcky and nonplasUc many fine medium and coarse roots 25 percent pebbles strongly acid clear smooth boundary Bw-15 to 20 inches, dark yellowish brown (10YR 3/4) very gravelly sandy loam light olive brown (2 5Y 514) dry weak fine subangular blocky structure loose very friable nonsticky and nonelastic, many fine medium and coarse roots 55 percent pebbles, medium acid, clear smooth boundary C-20 to 60 inches dark yellowish brown (10YR 4/4) extremely gravelly sand, yellowish brown (10YR 5/4) dry single grained loose, few fine roots, 80 percent pebbles, 10 percent cobbles slightly acid The thickness of the solum ranges from 15 to 25 inches The content of coarse fragments in the control section ranges from 50 to 85 percent The weighted average texture of this section is very gravelly sand or extremely gravelly sand The umbric epipedon is 10 to 20 inches thick The A horizon has hue of tOYR or 7 5YR, value of 3 or 4 when dry and chroma of 1 or 2 when moist or dry It is medium acid or strongly acid The Bw horizon has value of 4 or 5 when dry and 3 or 4 when moist It is very gravelly sandy loam, very gravelly loam, or extremely gravelly sandy loam The C horizon has hue of tOYR or 2 5Y, value of 5 or 6 when dry and 4 or 5 when moist and chroma of 3 or 4 when dry or moist It is extremely gravelly sand or extremely gravelly loamy sand and is slightly acid or neutral Sultan Sertes The Sultan series consists of very deep moderately Soil Survey well drained soils on flood plains These soils formed in alluvium Slope is 0 to 3 percent Elevation is 20 to 75 feet The average annual precipitation is 40 to 50 inches the average annual air temperature is about 50 degrees F and the average frost free season is 150 to 200 days These sods are fine-silty mixed nonacid, mesic Aquic Xerofluvents Typical pedon of Sultan silt loam 7 miles east of Lacey about 1 000 feet east and 1,975 feet north of the southwest corner of sec 16 T 18 N R 1 E Ap-0 to 7 inches dark yellowish brown (10YR 3l4) silt loam brown (10YR 5/3) dry moderate fine and medium granular structure, slightly hard, very friable slightly sticky and slightly plastic many fine, medium and coarse roots, many very fine and tine tubular pores slightly acid, abrupt smooth boundary BA-7 to 20 inches dark yellowish brown (tOYR 4(4) silt loam, brown (10YR 5/3) dry moderate fine and medium subangular blocky structure slightly hard very friable slightly sticky and slightly plastic many very fine fine, and medum roots many very fine and fine tubular pores slightly acid, clear wavy boundary Bw1-20 to 25 inches dark brown (10YR 3/3) silt loam, grayish brown (2 5Y 5/2) dry, common tine prominent red (2 5YR 5/8) mottles moderate fine and medium subangular blocky structure, slightly hard very friable, slightly sticky and slightly plastic, common fine and medium roots common very fine and fine tubular pores, slightly acid, gradual wavy boundary Bw2-25 to 45 inches dark brown (10YR 4l3) silt loam light brownish gray (10YR 6/2) dry common medium prominent red (2 5YR 5/8) mottles, moderate medium and coarse subangular blocky structure, slightly hard, very friable slightly sticky and slightly plastic, few very fine and fine roots, few very fine and fine tubular pores slightly acid, gradual wavy boundary C-45 to 60 inches, grayish brown (tOYR 5/2) silt loam, light gray (10YR 7/2) dry, common medium prominent dark brown (7 5YR 4/4) mottles massive, slightly hard, very Enable, slightly sticky and slightly plastic, slightly acid The soils are slightly aad or neutral in the control section and range from slightly aad to strongly acid below a depth of 40 inches Mottles that have chroma of 3 or more are at a depth of more than 20 inches Thurston County Washington The Ap horizon has hue of 10YR value of 3 or 4 ~rrhen morst and chroma of 3 or 4 when dry The 8w (horizon has hue of 10YR or 2 SY value of 3 or 4 when moist and 5 or 6 when dry and chroma of 2 or 3 when moist or dry It has thin strata of fine sandy loam to silty 'clay loam The C honzon has hue of 10YR, value of 5 to 7 when moist and chroma of 2 when moist ~acoma Sertes The Tacoma series consists of deep very poorly drained sods on flood plains and deltas These soils ormed in alluvium that has a high content of volcanic sh Slope is 0 to 1 percent Elevation is 0 to 20 teet The average annual preapitation is 40 to 50 inches, the verage annual air temperature is about 50 degrees F rid the average frost free season is 160 to 200 days These soils are coarse silty mixed acid merit Sulfic luvaquents Typical pedon of Tacoma sdt loam 6 miles northeast f Lacey about 1 000 feet north and 300 feet west of the southeast corner of sec 31 T 19 N , R 1 E ~e-3 inches to 0, mat of fine grass roots A-0 to 7 inches dark brown (10YR 3/3) sdt loam ' grayish brown (10YR 5/2) dry many medium distinct dark brown (7 5YR 4/4) mottles moderate fine angular blocky structure, friable, nonsticky and slightly plastic many medwm and fine roots extremely acid abrupt smooth boundary g1-7 to 23 inches, dark grayish brown (10YR 4/2) sdt loam light brownish gray (10YR 6/2) dry many fine ' distinct dark yellowish brown (tOYR 4/4) mottles moderate medwm prismatic structure Enable slightly sticky and slightly plastic many medwm and fine roots extremely acid abrupt smooth boundary ~g2-23 to 40 inches dark grayish brown (tOYR 4/2) silt loam light brownish gray (10YR 6/2) dry many fine distinct dark yellowish brown (10YR 4/4) ' mottles weak medwm prismatic structure friable nonsticky and slightly plastic, few fine roots extremely acid clear smooth boundary ~g3-40 to 50 inches grayish brown (10YR 5!2) silt loam gray (10YR 6/1) dry massive friable slightly sticky and slightly plastic extremely acid abrupt smooth boundary 'Cg4-50 to 60 inches dark greenish gray (5GY 4/1) clay common medium distinct brown (7 SYR 4/4) mottles massive friable very sticky and very ' plastic few fine tubular pores strongly acid The soils are more than 60 inches deep but the t 159 rooting depth is limited by the water table unless the ¢lant is hydro¢hytic Some pedons have layers oS muck 1 to 4 inches thick These layers have a cumulative thickness of less than 16 inches The content of weighted organic carbon is less than 12 percent in the control section The A or Ap horizon has hue of tOYR or 5Y, value of 3 or 4 when moist and chroma of 1 or 2 when moist It has faint or distinct mottles It is strongly acid to extremely acid The Cg horizon has hue of tOYR, 2 SY, or SY or is neutral in hue It has value of 3 to 6 when moist and 4 to 8 when dry and chroma of 0 to 2 when moist or dry It has faint to prominent mottles It is very strongly acid or extremely acid The 2Cg horizon is stratified clay to sand It varies in texture within short distances It is very strongly acid or extremely acid The depth to this honzon is more than 60 niches m some areas Tentno Sertes The Tentno series consists of moderately deep, well drained soils on terminal moraines These soils formed m glacial till over glacial outwash Slope is 3 to 65 percent Elevation is 50 to 400 feet The average annual preapitation is 45 to 60 inches, the average annual air temperature is about 50 degrees F, and the average frost free season is 150 to 200 days These soils are coarse loamy, mixed merit Dystric Entic Durochrepts Typical pedon of Tentno gravelly loam 3 to 15 percent slopes, 2 miles northwest of Littlerock about 800 feet east and 400 feet north of the southwest corner of sec 27 T 17 N R 3 W Al-0 to 5 inches dark reddish brown (5YR 2/2) gravelly loam, dark grayish brown (10YR 4/2) dry, moderate fine granular structure, soft very friable, nonsticky and nonelastic 30 percent pebbles, many very fine, fine, medwm and coarse roots, many very fine tubular pores strongly acid clear smooth boundary A2-5 to 11 inches dark yellowish brown (10YR 3(4) gravelly loam dark brown (10YR 4/3) dry moderate fine granular structure soft very friable, nonsticky and nonelastic 30 percent pebbles many fine, medwm and coarse roots many very fine tubular pores medium acid, clear smooth boundary Bw1-11 to 21 inches, dark brown (7 5YR 4/4) gravelly loam fight yellowish brown (10YR 6/4) dry weak fine subangular blocky structure, soft, very friable nonsticky and nonelastic, 30 percent pebbles, `J SOIL SURVEY OF THURSTON COUNTY, WASHINGTON - SHEET NUMBER 24 1 1 1 1 1 1 1 . ~~ --~ .~ i yon .'~~ 5~ w a U 2 5 w 104th Ave SE ~- « I ~~ 5/ --o ----~------ N Uvuw I w ,' ~ ~ '~ I o 0 1 G M1LL P~ ~ B I ~ ~ / E*~N/~o~~ ~ ~f g o ~,_--, 25 NPE II LANbSCAPE BUFFER NEw CONNECTION ...~ TD 107TH I I IIII I I I I I II II I I I II _ n nnulw ~-' NEW CONNECTION TO 1 WTH ~..r 3000 0 3000 SCALE IN FEET TEST PIT LOCATIONS 8 TP-2 SAIL LOG LAND SL-2 S^IL LOG POND SP-1 NOTE BOUNDARY AND TOPOGRAPHY ARE BASED ON MAPPING PROVIDED TO E3RA BY ERICKSON MCGOVERN, PLLC AND OBSERVATIONS MADE IN THE FELD THE INFORMATION SHOWN DOES NOT CONSTITUTE A FIELD SURVEY BY E3RA, E 3RA Inc P O BOX 44890 TACOMA WA 98444 253-537-9400 off 253-537-9401 tax www e3ra com PROJECT YELM JUNIOR HIGH SCHOOL TITLE TEST PIT LOCATIONS DESIGNER CRL DRAWN BY CRL CHECKED BY JEB DATE 9/2~ 6000 JOB NO T03118 SCALE 1" = 3000' SHEET FIGURE 2 FILE YJHS-PIT DWG N W - E 1 1 1 1 1 1 1 1 1 1 1 1 ,~, 'T ~' .rc { 'f ` ~ ~ T' ~ ~ ~ _~ i i } GEOTECHNICAL ENGINEERING EVALUATION NEW YELM JUNIOR HIGH SCHOOL CARTER STREET SOUTH EAST YELM, WASHINGTON Submitted to: Yelm School District PO Box 476 Yelm, WA 98597 Submitted by: E3RA, Inc. PO Box 44890 Tacoma, WA 98444 October 15, 2004 T04155 ~~ ;. PO Box 44890 Tacoma WA 98444 253-537-9400 253-537-9401 fax 1 E3RA 1 October I5, 2004 Yelm School Dismct P O Box 476 Yelm, Washington ' Attention Erhng Birkland SubJect Geotechmcal Engineering Evaluation New Yelm Junior High School Carter Street South East Yelm, Washington DeazErling ' E3RA is pleased to submrtthis report descnbing theresults ofour geotechnical engmeermg evaluation for the new Junior Htgh School to be located west of Mdl Pond Elementary School E3RA conducted prehmmary subsurface explorations on the protect site in the summer of 2003 This report has been prepared for the exclusive use of the Yelm School District and then consultants, for specific apphcahon to this protect, m accordance with generally accepted geotechmcal engmeermg practice ' 1 0 SITE AND PROJECT DESCRIPTION The site is an irregularly-shape parcel located west of the existing Mil Pond Elementary School on the southwest side of Yehn, Washington, as shown on the enclosed Location Map (Figure 1) Plans call for the construction of a main school building, bus loops, vehicle parking areas, athletic fields, and ' portable classrooms The school budding will be 1'/, stones with slab-on-grade floors Infiltration ponds, planned For the northwest acid south comers of the site, will dispose of collected runoff water We understand that the part of the area near the east side of the planned construction was mined for sand and grave] and backfilled with fill sods ' 2 0 EXPLORATORY METHODS We conducted prehmmary explorations onsrte dunng the summer of2003 and we further explored surface and t subsurface conditions atthe proJectsite on October3, 2004 Ourexplorahon program comprsed the following elements ' A surface i econnaissance of the site, • Two prehmmary test pits (designated TP-1 and TP-2), advanced on July, 2003, near the ' proposed school budding, October 15, 2004 T04155 / Yelm Junior High School 1 1 1 1 1 E31Z4, Inc • Ten test pits, (designated SL-I through SL-10), advanced on October 3, 2004, m the vicinity of the proposed school budding m locations surveyed by J W Morrissette and Associates, Tnc , • Frve test pits for infiltration analysis, (designated SP-1 through SP-5), advanced on October 3, 2004, m the proposed mfiltrahon ponds in locations surveyed by J W Morrissette and Associates, hic • Four serves of mfiltrahon tests, performed on soils within the proposed infiltration ponds Two Gram Size Analyses performed on sail samples from beneath the site, and • A review of published geologic and seismologic maps and literature Table 1 summaztzes the approximate functional locations and termination depths of our subsurface explorations, and Figure 2 depicts then approximate relative locatons The following text sections describe the procedures used for excavation of test pits TABLE 1 APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS Termination FunctronalLocatio° Depth Exploration (feet} TP-1 South side planned school building 9% TP-2 North side planned school building 9 SL-1 Southeast of planned school butldmg 9 SL-2 East of planned school butldmg 16'/, SL-3 South side of east part of planned school bmlding 9 SL-4 North side of east part of planned school building 10 SL-5 West part of planned school budding 10 SL-6 North side planned school budding 10 SL-7 North side planned school butldmg 12 SL-8 West end planned school bmlduig 10 SL-9 South of west end planned school butldmg 10 SL-10 East edge planned school budding 8 SP-1 Northwest part south mfiltrahon facility 10 SP-2* Southwest part south mfiltrahon facility 11 SP-3* Southeast part south mfiltrahon facility 7'h SP-4* South part north mfiltrahon facility ] 3 SP-5* North part north mfiltrahon facdRy 12 Elevation datum Stte Plan * Includes Infiitratton Test October 15, 2004 E3RA Inc T04155 / Yelm Junior High School The specific number and locations of our explorations were selected m relation to the existing srte features, under the constraints of surface access, underground utility conflicts, and budget considerations We estimated ' the relative location of each exploration Consequently, the data listed m Table 1 and the ]ocatinns depicted on Figure 2 should be considered accurate only to the degree peimrtted by our data sources and implied by our measuring methods t It should be realized that the explorations performed and utilized for this evaluation reveal subsurface condtttons only at discrete locations across the protect srte and that actual condmons m other azeas could vary furthermore, the nature and extent of any such variations would not become evident until additional explorations are performed or until construction activities have begun ifsigntficantvaziationsare observed at that time, we may need to modify our conclustous and recommendations contained m this report to reflect the ' actual srte condtttons 2 1 Test Pit Procedures Our explot atory test pits wet e excavated wrth atrack-mounted excavator by an owner-operator under contract to E3RA A geologist from our firm observed the test pit excavations, collected samples, and logged the subsurface condtttons The enclosed Test Ptt Logs indicate the vertical sequence of sods and materials encountered m each test pit, based on our field classifications Where a soil contact was observed to be gradational or undulating, our logs ' mdtcate the average contact depth We estunated the relative density and consistency of Uie m-situ soils by means of the excavation characteristics and the stability of the test pit sidewalk Samples were stored m au- hght containers and transported to our Tacoma facility for laboratory testing Our togs also mdtcate the ' approximate depths of any stdewall caving or groundwater seepage observed m the test pits and the depths at which samples were collected ' 2 2 Infiltration Test Procedures Our infiltration tests were performed m general accordance wrth the procedures prescribed m the EPA manual entitled On-Site Wastewater Treatment and Disposal Systems, except as modified by onstte condtttons ' Because invert elevations were not available at the tune of our tests, a test pit was excavated to a nominal depth of 3Yz to 4Yz feet, a 6-inch-diameter PVC pipe was tamped approximately 3 inches into the sod at the bottom of the test pit, 2 inches of coarse, clean dram rock was placed at the bottom of Uie pipe to prevent scout mg, and sod was placed and tamped outside the pipe for stabilization The pipe was then filled twice with] footofwater to pre-saturate the test soils If I foot of water infiltrated the test sods m less than 10 minutes, further saturation was deemed unnecessary and the infiltration test proceeded If 1 foot of water infiltrated the test soils m more than 10 minutes, the test was ended and a soil sample was collected for textural analysis After rt was determined that 1 foot of water would infiltrate test sot is m less than 10 minutes, the pipe was then filled wrth 6 inches of water, and, because srte soils were found to be rapidly pet meable, the time regmred for infiltration ofthe entire 6 inch column ofwater was recorded We repeated this procedure three tunes at each test location and used only the slowest of the 3 recorded infiltration rates m our aualysis After completion of all tests, the PVC pipes were extracted and the excavation was extended at least 3 feet deeper to identify soil conditions below the tested elevation October 15 2004 E3RA, Inc T04155 / Yelm Junior High School ' 3 0 SITE CONDITIONS The following sections oftext present our observations, measurements, findings, and interpretations regarding, surface, soil, groundwater, seismic, and liquefaction conditions 3 1 Surface Conditions ' The srte is relatively flat m the vicinity of the planned school building Just west of the planned school bm(ding, a very shallow Swale, trending north to south, grades very gently down to the south ' Vegetation at the east edge of the planned school building is grass that is part of the outfield of a baseball diamond This ball field is part ofthe grounds ofMill Pond Elementary School Vegetation on the remainder ' ofthe srte consists of high pasture grass, scotch broom, and an occasional, scattered fir tree Several old fruit trees grow m the vicinity of the infiltration pond plaimed for the south part of the srte ' No hydrologic or erosional features were observed onsite Fences separate the protect site from neighboring properties except on the east boundary with Mill Pond ' School An old wire fence, tiendmg north-south, traverses the srte across the central part of the planned school ' building An old, two-tire pathway, which has been worn into the pasture grasses onsrte, winds across the parcel 3 2 Sod Conditions Our on-site explorations revealed that soil that soil conditions are relatively wufonn across the site, but there are some important exceptions Generally, we observed a %s to 2 feet thick layer of sod and topsoil overlying 1 to 2 feet of volcanic ash-rich soil The volcanic ash rs intermittently mixed with glacial outwash Where wunixed with glacial outwash, ct rs soft and comprised mostly ofsilt Where mixed with glacial outwash, rt is medium dense and comprised mostly ofsand and gravel Underlying the volcanicash-rich layer, we observed medmm dense to dense, weathered and unweathered, glacial outwash consisting of sandy gravel with few fines, abundant cobbles, and occasional small boulders important exceptions to this general soil stratigraphy were observed at the east edge of the planned school bwldmg, where fill soils were observed, and at the northwest part of the south infiltration pond, where some partially cemented soils were observed ' In the vicinity of the planned school bwldmg acid surrounding portable buildings and pavements, m test pits TP-1, TP-2, and SL-l, and SL-3 through SL-9, we observed 4 inches to 2 feet of sod and topsoil overlying up ' to 2 feet of soft, silty volcanic ash or, mtermcttently, medimn dense volcanic ash mixed with gravelly glacial outwash The topsoil and soft, silty volcanic ash layers are thickest m test pit SL-8, located on the west part of the planned budding Thece, topsod is 2 feet thick and is underlain by 2 feet of soft, silty volcanic ash ' Fill underlces the east ] 8 to 20 feet ofthe planned school footprint Our test pits m that vicuuty, SL-2 and SL- 10, mdccate that the fill was placed over native, medium dense glacial outwash This fill is probably backfill for the boi row pit that reportedly underlies the east part of the site It appears to consist of a mix of volcanic ash and sandy, gravel ly glacial outwash ft is consolidated to a medmm dense state Soils observed m test pit SL-] 0 indicate that the fill/native sml contact is near the surface 18 to 20 feet west of the easternmost edge of the building footprint and dips down to the east at a grade of about 2H 1 V Fill sals are 8 feet thick about 5 4 October 15, 2004 E3RA, Inc TD4155 i Ye1m Jurnor high School feet east of the east bwilding perimeter We estimate that they aze about 10 feet thick at the east building perimeter ' Soil conditions are somewhat variable m the vicinity ofthe infiltration pond planned for the south part ofthe site In test pit SP-l, located in the northwest part of the south pond, we observed a foot of sod and topsoil overlying 2%x feet of silty sand At a depth of 3%x feet, we observed afoot-thick layer of gravelly sand with some silt, this layer became partially cemented from 4'/x to 9 feet From a depth of 9 to the termination of the exploration at a depth of 11 feet, we encountered very dense, silty, gravelly sand In the southwest part of the south infiltration pond, m test prt SP-2, we observed 2%x feet of topsoil and silty, sandy gravel oveilymg weathered glacial outwash consisting of sandy gravel with few fines Unweathered glaciai outwash, similar m consistency to the overlying weathered glacial outwash, was encountered at 3 %x feet and was found to extend to a depth of 7 feet From a depth of 7 feet to the terminus of the exploration at a ' depth of 1 1 feet, we observed silty gravel with some sand and abundant cobbles In the southeast part ofthe south infiltration pond, m test pd 5P-3, we observed 2'/z feet of silty volcanic ash and volcanic ash mixed with sandy gravel overlying, to a depth of 7 %x feet, glacial outwash consisting of sandy gravel with few fines Refusal was met at a depth of 7'h feet, where either bedrock or a layer of ]azge boulders was encountered t In the north infiltration pond, m test pits SP-4 and SP-5, we encountered 2'/x feet of sod, topsoil, and silty, sandy gravel overlying, to the termination of the explorations at 12 to 13 feet, glacial outwash consisting of ' sandy grave] with few fines 1 ll 1 TABLE 2 LABORATORY TEST RESULTS FOR INFILTRATION ZONE SOILS Soil Sample, Sod Type, Location Gravel Content Sand Content Silt Content De th (feet) (ercent ercent) ercent SL-5, S-I, 3-8 Unweathered Outwash, school building 82 17 1 SP-1, S-1, 4%-5%x Unweathered Outwash, south pond 35 60 5 The attached exploration togs provide a detailed description of the sal strata encountered m our subsurface explorations, and the attached lab sheets graphically display our laboratory results 3 3 Groundwater Conditions At the time of our explorations, (July 2, 2003 and October 4, 2004), we dtd not observe groundwater underlying the school budding and surrounding structures or the north infiltration pond We observed moderate to rapid groundwater flow at a depth of 7 %z feet m test pit SP-3, Located on the southeast part of the south infiltration pond We encountered slow groundwater seepage at a depth of 8 feet m test prt SP-2, located m the southwest paR of the south mfiltiatron pmid We do not expect that significant quantities of groundwater will not be encountered m excavations for the proposed building At all times ofthe year groundwater levels would likely fluctuate m response to precipitation patterns, off=sRe construction activities, and site utilization October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School 3 4 Sersmrc Condrhons ' Based on our analysts of subsurface exploration logs and our review of published geologic maps, we interpret the on-site soil conditions to correspond with a seismic site class So, as defined by Table 1615 1 5 ofthe 2003 International Budding Code (IBCJ According to the IBC, the site a Sersmic Region 3 ' 3 5 Liquefaction Potential Ltquefachon is a sudden increase m pore water pressure and a sudden loss of soil shear strength caused by ' shear strains, as could result from an earthquake Research has shown that saturated, loose sands with a fines (silt and clay) content less than about 25 percent are most susceptible to Ltquefachon Our on-site subsurface explorations dtd not reveal saturated (or potentially saturated), loose silty sand layers or lenses ' 3 6 Infiltration Condrhons and Infiltration Rate Two infiltration preliminary mfilffahon pond locations have been identified onsrte The first ofpond location ' is m the northwest corner of the site and the second pond location is m the northwest comer of the site Our pre-saturation tests indicated that tested soils were rapidly permeable everywhere except m test pit SP-I, located in the northwest part of the south infiltration pond There a sample was collected and a textural analysis was performed Our explorations m the north pond location, test pits SP-4 and SP-5, indicate that a rapidly permeable layer underlies the north infiltration pond area m a zone that begins below 2'/i feet and extends beyond depths of 12 to 13 feet Our field infilffahon tests found that water infiltrates soils within this infiltration zone at a rate in excess of 1 minute per inch Generally, the maximum accepted infiltration rate is 1 minute per inch Applying a Factor of Safety of 2, we recommend a Design Infiltratwn Rate is 2 minutes per Inch 1 Infiltration conditions are more variable wdhm the footprint of the south infilffahon pond Our pre-saturation of the partially cemented sods lying at depths below 4'h feet and above 9 feet m test pit SP-1 require more than 0 minutes, so a sample was collected and a textural analysis was conducted Our gram size analysis indicates that this sod contains 5 percent sdt, 60 percent sand, and 35 percent gravel Accordmg to the U S D A Textural Triangle, the analyzed sod is loamy sand, with apre-design infiltration rate of 5 minutes per inch However, because some cementation was observed, we recommend a Factor of Safety of 5 fherefae, the Design Infiltration Rate for soils within the mfilhation zone m the northwest part ofthe south infiltration pond is 25 minutes per inch - ~--- -- Fauly rapidly permeable smis were observed m SP-2, located m the southwest part of the south pond area, between the depths of 2%z and 7 feet, however, groundwater was encountered there at a depth of 8 feet Our field infiltration rate for the zone between 2%, and 7 feet is over 1'/z minutes per tnch After the application ofa Safety Factor of 2, we recommend a Design infiltration rate of 4 minutes per inch there Rapidly permeable soils were encountered m SP-3, located m the southeast part ofthe south pond area between the depths of 2'/z and 7'h feet, and groundwater was encountered there at a depth of 7'/z feet Based on our mfilffation test m the this part ofthe south pond, we recommend an infiltration rate of L minute per inch and, after application of a Safety Factor of 2, a Design htfiltration rate of 2 minutes per inch The results of our infiltration tests are presented m Table 2 Because infiltration was rapid, we recorded the time necessary fora 6 inch high column of water to infiltrate completely 1 '~ 1 1 October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School TABLE 2 FIELD INFILTATION TEST RESULTS, YELM JUN10R HIGH Field In£dtrahon Rate Test Ptt Location, Depth of Test, Sod Type for 6 mch Column SP-2 Southwest part south pond, 3'/z feet, outwash with few/some fines 9 mm 15 sec/6 inches SP-3 Southeast part south pond, 3'/z feet, outwash with few fines 2 mm 17 sec/6 Inches SP-4 South part north pond, 4 feet outwash wrth few fates 3 mm 3 sec/6 Inches SP-5 North part north pond, 3% feet, outwash with few fines 19 sec/6inches ' In test pit SL-1, located south of the east part ofthe planned school bmlding, rapidly permeable sandy gravel with few fines were observed from a depth of 1 %z to the termination of the exploration at a depth of 9 feet. Our field classification indicates that soils there have the maximum accepted infiltration rate ofl minute per ' mch Applying a Factor of Safety of 2, we recommend a Design Infiltration Rate is 2 minutes per mch m this general area ' 4 0 CONCLUSIONS AND RECOMMENDATIONS Plans call for the construction of a main school budding 1'h stones high, bus loops, vehicle parking areas, athletic fields, portable classrooms and infiltration ponds We offer the following general geotechnical ' conclusions and recommendations concerning this protect • Feasibility Based on our field explorations, research, and analyses, the proposed constmchon ' appears feasible from a geotechnical standpoint, provided that the recommendations in Section 5 and in this report are followed ' Foundatton Options We recommend conventional spread footings that beaz on subgrades consisting of organic-free, medium dense or denser native soils Beazing pads that are 3 feet thick will be necessary for the footings on the east 15 feet of the school building, where fill ' soils are present Bearing pads may possibly be necessary where thick topsoil and soft silt extend several feet below existing grades, as on the west side ofthe school building footprint ' Recommendations for spread footings and beai mg pads are provided m Section 5 • Floor Options We recommend concrete slab-on-grade floors for the structure Some over- ' excavation of floor subgrade soils wdl probably be necessary where thick topsoil and soft sdt extend several feet below ewstmg grades Recommendations for slab-on-grade floors are tncluded m Section 5 ' Infiltration Conditions A thick layer of rapidly permeable soils underlie the north infiltration pond site and the area south of the east part of the planned school Fairly shallow ' groundwater and a discontinuous, thinner, raptdly permeable soil Layer partially undeihe the south mfilUatton pond site ' The following text sections of this report present our specific geotechnical conclusions and recommendatrons concerning site preparation, spread footings, slab-on-grade floors, drainage, asphalt pavement, and struchiral fill The WSDOT Standard Specifications and Standard Plans cited herein refer to WSDOT publications M41-10,StandardSpeceficahonsforRoad,6ndge,andMuntcepalConstruction,andM21-Ol,StandardPlans for Road, Bndge, and Muntcrpal CO7TSl7 uckan, respectively 7 October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School 4 1 Srte Preparatiop Preparation of the protect site should involve eroston control, temporary drainage, cleazing, stripping, cutting, filling, excavations, and subgrade compaction ' Erosion Control Before new construction begins, an appropriate eroston control system should be installed This system should collect and filter all surface run offthrough either silt fencing or a series ofproperly placed and secured straw bales We anttctpate a system of berms and drainage ditches around construction areas will provide an adequate collectron system if stlt fencing is selected as a filter, this fencing fabric should meet the ' requuements of WSDOT Standard Spectftcation 9-33 2 Table 3 In addition, sdt fencing should embed a minimum of 6 Inches below existing grade If straw baling rs used as a filter, bales should be secured to the ground so that they will not shift under the weight of retained water Regardless of the silt filter selected, an ' eroston control system regwres occasional observation and maintenance Specifically, hales m the filter and areas where the filter has shifted above ground surface should be replaced or repaired as soon as they are identified Temporarv Drama¢e We iecontmend mtercepttng and drvertmg arty potential sources of surface or near-surface water within the construction zones before stripping begins Because the selection of an ' appropriate drainage system will depend on the water quantity, seasou, weather conditions, construction sequence, and contractor's methods, final dectsrons regarding drainage systems are best made to the field at the time of construction Based on our current understa»dmg of the construction plans, surface and subsurface ' condrttons, we anttctpate that curbs, berms, or ditches placed around the work areas will adequately intercept surface water runoff ' Clearme and Shtpmnir After surface and near-surface water sources have been controlled, the coitstructton areas should be cleared and stepped of all sod and topsoil Our explorations indicate that topsotl and sod average about ]foot thick, but locally can be much thicker, as on the west part of the school footprint, where 2 ' feet of sod and topsoil overlie 2 feet of soft silt, volcanic ash Stripping is best performed during a period of dry weather Site Excavations Based on our explorations, we expect that excavations will medmm dense to dense glacial ' outwash No special equipment wdl be necessary to rapidly excavate site soils Dewatenn~ Our site explorations did not encountered groundwater m the vicinity of the planned school building and we do not anticipate that significant groundwater flow wdl be encountered during earthwork activities However, tf groundwater is encountered, we anticipate that an internal system of ditches, sumpholes, and pumps will be adequate to temporarily dewater excavations Temporarv Cut Slopes All temporary sml slopes associated with stte cutting or excavations should be adequately inclined to prevent sloughing and collapse Temporary cut slopes m site soils should be no steeper ' than 1'h H 1 V, attd should conform to WISHA regulations Sub¢iade Compaction Exposed subgrades for footings and floors should be compacted to a fine, unyielding ' state before new concrete or fill sods are placed Any localized zones of looser granular soils observed within a subgrade should be compacted to a density commensurate with the surrounding soils In contrast, any organic, soft, or pwnpmg soils observed wdhin a subgrade should be overexcavated and replaced with a ' swtable structural fill material Overexcavation of the soft, silty volcanic ash that underlies the budding site at of depths of up to 4 feet will be ' necessary Areas where volcanic ash is mixed with sandy, gravelly glactal outwash, and is medtum dense or denser, will not need overexcavation October 15, 2004 E3RA Inc T04155 / Yelm Junior High School Stte Filling Our conclusions regazdmg the reuse of on-sde soils and our comments regazding wet-weather filling are presented subsequently Regardless of soil type, all fill should be placed and compacted according to our recommendations presented m the Structural Ftll section of this report Specifically, building pad fill soil should be compacted to a uniform density of at least 95 percent (based on ASTM D-1557) On-Site Soils We offer the following evaluation of these on-site soils m relation to potential use as structural fill • sdlYfClQl OYgll111CSOlIS The sod and topsoil that overlies the site at depths up to 2 feet is not suitable for use as structural fill under any circumstances, due to high organic content Consequently, these materials can be used only for non-structural purposes, such as m ' landscaping areas • i~olcanzc Ash The black, soft, volcanic ash that underlies the topsoil layer intenmttently over ' the buildmg sde is extremely sensitive to moisture content variations and will be difficult to impossible to reuse or to compact m situ ' Yolcmztc Ash/Glacial Ouhvash Mix Tins soil underlies the site intermittently It consists primarily of sand and gravel It is somewhat sensitive to moisture content variations and will be difficult to reuse during wet weather conditions • Weathered and Unweathered Glacial Outwash These soils, comprised of sandy gravel with few fines and abundant cobbles, are relatively msensrtwe to moisture content variations and ' can be reused during most weather condttion, provided particles over 6 niches are removed Permanent Slopes All pennaz~ent cut slopes and fill slopes should be adequately inclined to reduce long-term raveling, sloughing, and erosion We generally recommend that no permanent slopes be steeper than 2H 1 V ' For all soil types, the use of flatter slopes (such as 2Y,H 1V) would further reduce long-term erosion and facilitate revegetation 1 Slooe Protection We recommend that a permanent berm, Swale, or curb be constructed along the top edge of all permanent slopes to intercept surface flow Also, a hardy vegetative groundcover should be established as soon as feasible, to further protect the slopes from runoff water eiosion Altemahvely, permanent slopes could ' be armored with quarry spans or a geosynthetic erosion mat 4 2 Spread Foohnes In our opinion, conventional spread footings will provide adequate support for the proposed school buffding if the subgrades are properly prepared ' Footma Depths aitd Widths For frost and erosion protection, the bases ofall exterior footings should beai at least 18 inches below adjacent outside grades, whereas the bases of interior footings need bear only 12 inches below the surrounding slab surface level To reduce post-construction settlements, continuous (wall) and ' isolated (column) footings should be at least 18 and 24 niches wide, respectively Bearine subgrades Footings should bear on medmm dense or denser, undisturbed native sods which have ' been stripped of surficial organic sods, or on properly compacted structural fill which bears on undisturbed, medwm dense or denser native soils which have been stopped of surficial organic soils In general, before footing concrete is placed, any localized zones of loose soils exposed across the footing subgrades should be compacted to a firm, unyielding condition, and any localized zones of soft, organic, or debris-laden soils should be overexcavated and replaced with suitable structural fill The soft volcanic ash, 9 October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School which is not Waxed with gravelly glacial outwash and prunazily consists of silt, is difficult or impossible to 1 adequately compact and well probably have to be overexcavated Subgrade Observation All footing subgrades should consist of firm, unyielding, native soils or structural fill materials compacted to a densely of at least 95 percent (based on ASTM D-1557) Footings should never be ' cast atop loose, soft, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces covered by standing water ' Beazmg Pressures ht our opuuon, for static loadntg, footings that beat on properly prepazed subgrades that consist of glacial outwash or the medmm dense ash/outwash mix can be designed far a maximum allowable soil bearing pressure of 2,500 pounds per square foot (psf) A one-third mctease in allowable soil bearing capacity may be used for short-term loads created by seismic or wind related activities Footing Settlements Assuming that structural fill sods are compacted to a medmm dense or denser state, we ' estimate that total post-construction settlements of properly designed footings bearing on properly prepared subgrades well not exceed 1 inch Differential settlements for comparably loaded elements may approach one- half of the actual total settlement over horizontal distances of approximately 50 feet Footme Backfill To provide erosion protection and lateral load resistance, we recommend that all footing excavanons be backfilled on both sides of the footings and stemwalls after the concrete has cured Either ' imported structural fill or non-organic on-site soils can be used for this purpose, contingent on suitable moisture content at the time of placement Regardless of soil type, all footing Backfill soil should be compacted to a density of at least 90 percent (based on ASTM D-1557) ' Lateral Resistance Footings that have been properly backfilled as recommended above will resist lateral movements by means ofpassrve earth pressure and base friction We recommend using an allowable passive earth pressure of 275 pounds per square foot for the glacial outwash onsite and an allowable base friction ' coefficient of 0 35 4 3 Slab-On-Grade Floors In our opmton, soil-supported slab-on-grade floors can be used m the proposed structure ifthe subgrades are properly prepared We offer the following conunents and recommendations concerning slab-on-grade floors ' Floor Subbase Because ofthe intermittent nature ofthe soft, silty volcanic ash that undeilies the site, the need and extent of subbases should be based on actual subgrade conditions observed at the time of construction When a subbase is needed, subbase fill should be compacted to a density of at least 95 percent (based on ASTM D-1557) Camllary Break aitd Vauor Barrier To retard the upward wicking of moisture beneath the floor slab, we ' recommend that a captl lacy break be placed over the subgrade Ideally, this capillary break would consist of a 4-inch-thick layer of pea gravel or other clean, uniform, well-rounded gravel, such as "Gravel Backfill for Drams" pet W SDOT Standard Specification 9-03 12(4), but clean angular gravel can be used if rt adequately ' prevents capillary wicking In additton, a layer of plastic sheeting (such as Crosstuff, Vtsqueen, or Moistop) should be placed over the capillary break to serve as a vapor bamei During subsequent casting ofthe concrete slab, the contractor should exercise care to avoid puncturing this vapor barrier ' 4 4 Drainage Systems In our opinion, the proposed structure should be provided with permanent drainage systems to reduce the risk offuture moisture problems We offer the following recommendations and comments for drainage design and construction pwposes 10 1 October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School Perimeter Drams W e recommend that the retail building be encvcled wrth a peruneter dram system to collect seepage water Thu dram should consist of a 4-inch-diameter perforated pipe wrthm au envelope ofpea gravel ' or washed rock, extending at least 6 inches on all stiles ofthe pipe, and the gravel envelope should be wrapped wrth filter fabnc to reduce the mrgration of fines from the surrounding soils Ideally, the dram invert would be installed no more than 8 inches above the base of the perimeter footings ' Subfloor Drams Based on the groundwater conditions observed in our site explorations, we do not infer a need for Subfloor drams Discharge Considerations If possible, all perimeter drauu should dischazge to a sewer system or other sortable location by gravity flow Check valves should be installed along any drainpipes that duchazge to a sewer system, to prevent sewage backflow into the dram system Runoff Water Roof-runoff and surface-runoff water should not dischazge into the peruneter dram system ' Instead, these sources should discharge into separate tightline pipes and be routed away from the building to a storm dram or other appropriate location Grading and Cappin¢ Final site grades should slope downward away from the buildings so that runoffwater ' will flow by gravity to suitable collection points, rather than ponding neaz the bwlding Ideally, the area sunrounding the building would be capped wrth concrete, asphalt, or low-permeability (silty) soils to mmunize or preclude surface-water infiltration ' 4 5 Asphalt Pavement Since asphalt pavements will be used for the driveways, bus loops, and pazking areas, we offer the following ' comments and recommendations for pavement design and construction Suberade Prepazation All soil subgrades should be thoroughly compacted, then proof-rolled with a loaded ' dump truck or heavy compactor Any localized zones of yielding subgrade disclosed during this proof-rolling operation should be over excavated to a maximum depth of 24 inches arxd replaced wrth a sortable structural fill material All structural fill should be compacted according to our recommendations green m the Structural ' Fell section Specrfically, the upper 2 feet of soils underlying pavement section should be compacted to at least 95 percent (based on ASTM D-1557), and all soils below 2 feet should be compacted to at least 90 percent ' Pavement Materials For the base course, we recormnend using unported crushed rock, such as "Crushed Surfacing Tap Course" per WSDOT Standard Specification 9-03 9(3) If a subbase course is needed, we recommend using imported, clean, well-graded sand and gravel such as "Ballast" or "Gravel Borrow" per WSDOT Standard Specrfications 9-03 9(1) and 9-03 14, respectively Conventional Asphalt Sections A conventional pavement section typically comprises an asphalt concrete pavement over a crushed rock base course Using the estunated design values stated above, we recommend ' using the following convectional pavement sections ' Minimum Thickness Pavement Course Car Parlung Car & Truck Travel Bus Lanes Areas Lanes ' Asphalt Concrete Pavement 2 inches 3 ruches 4 inches Crushed Rock Base 4 inches 6 inches 6 niches 1 Granular Fill Subbase (if needed) 6 inches 12 inches 2 inches ' ti October 15, 2QQ4 E3R.4, lnc T04155 / Yelm Junior High School Compaction and Observation All subbase and base course material should be compacted to at least 95 percent ' ofthe Modified Proctor maximum dry density (ASTM D-1557), and all asphalt concrete should be compacted to at least 92 percent of the Rice value (ASTM D-2041) We recommend that an E3RA representative be retained to observe the compaction of each course before any overlying layer is placed For the subbase and ' pavement course, compaction is best observed by means of frequent density testing For the base course, methodology observations and hand-probing aze more appropriate than density testing Pavement Ltfe and Maintemance No asphalt pavement is maintenance-free The above described pavement ' sections present our minimum recommendations for an average level of performance during a 20-year design life, therefore, an average level of maintenance wilt likely be required Furthermore, a 20-year pavement life typically assumes that an overlay will be placed after about 10 years Thicker asphalt and/or thicker base and ' subbase courses would offer better long-term performance, but would cost more radially, thuiner courses would be more susceptible to "alhgator" cracking and other failure modes As such, pavement design can be considered a compromise between a high uuual cost aitd low maintenance costs versus a low initial cost aitd ' higher maintenance costs 4 6 Structural Fill The term "structural fill" refers to any placed under foundations, retaunng walls, slab-on-grade floors, sidewalks, pavements, and other structures Our comments, conclusions, and recommendations concemmg structural fill are presented m the following pazagraphs ' Materials Typical structural fill materials include clean sand, gravel, pea gravel, washed rock, crushed rock, well-graded mixtures of sand and gravel (commonly called "gravel borrow" or "pd-run"), and miscellaneous ' mixtures of silt, sand, and gravel Recycled asphalt, concrete, and glass, which are derived from pulverizing the parent materials, are also potentially useful as structural fill in certain applications Soils used for structural fill should not contain any organic matter or debris, nor any individual particles greater than about 6 inches in ' diameter Fill Placement Clean sand, gravel, crushed rock, soil mixtures, and recycled materials should be placed in ' horizontal lifts not exceeding 8 inches in loose thickness, and each lift should be thoroughly compacted with a mechanical compactor Compaction Cntena Using the Modified Proctor test (ASTM D-1557) as a standard, we recommend that structural fill used for various on-site applications be compacted to the following minimum densities Fill Application Minimum ' Compaction Footing subgrade and bearing pad 95 percent Fouudatiou backfill 90 percent 1 Slab-on-grade floor subgrade and subbase 95 percent Asphalt pavement base and subbase 95 percent Asphalt pavement subgrade (upper 2 feet) 95 percent ' Asphalt pavement subgrade (below 2 feet) 90 percent Subgrade Observation and Compaction Testing Regardless ofmaterial or location, all structural fill should be 1 placed over fine, unyielding subgrades prepared m accordance with the S+te Preparation sectron of this report The condition of all subgrades should be observed by geotechmcal personnel before filling or construction begins Also, fill soil compaction should be verified by means of i^-place density tests performed during fill placement so that adequacy of sod compacAOn efforts may be evaluated as earthwork progresses ' 12 October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School Sort Rforstun; Considerations The surtabdrty of sods used for structural fill depends pnmarrly on their ' gram-size distribution and moisture content when they are placed As the "fines" content (that soil fraction passing the U S No 200 Sieve) increases, sods become more sensitive to small changes m moisture content Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, ' unyielding condition when the moisture content is more than 2 percentage points above or below optimum For fill placement during wet-weather site work, we recommend using "clean" fill, which refers to sods that have a fines content of 5 percent or less (by weight) based on the soil fraction passing the U S No 4 Sreve ' S 0 RECOM117ENDED ADDITIONAL SERVICES Because the future performance and integrity of the structural elements will depend lazgely on proper site preparation, drainage, fill placement, and construction procedures, monitoring and testing by experienced geotechmcal personnel should be considered an integral part of the construction process Consequently, we recommend that E3RA be retained to provide the following post-report services ' Review all construction plans and specifications to venfy that our design crrtena presented in this report have been properly integrated into the design, • Prepare a letter summarizing all review comments (if regmred by the city of Yelm), ' Check all completed subgrades for footings and slab-on-grade floors before concrete is poured, m order to venfy then beazing capacity, and • Prepare apost-construction letter summazizing all field observations, inspections, and test results (if required by the city of Yelm) ' 60 CLOSURE The conclusions and recommendations presented m this report are based, in part, on the explorations that we observed forthis study, therefore, ifvaziahons m the subgrade conditions aze observed at a ]atertune, we may need to modify this report to reflect those changes Also, because the future performance and integnty of the project elements depend largely on proper wtial site preparation, diamage, and construction procedures, monrtormg and testing by experienced geotechmcal personnel should be considered an integral part of the construction process E3RA is available to provide geotechmcal monrtoi mg of sods throughout construction ' 13 1 1 1 1 1 October'15, 20D4 T04155 / Yelm Junior High School E3RA, Inc We appreciate the opportunity to be of service on this protect Ifyou have any questions regarding this report or any aspects of the protect, please feel free to contact our office Sincerely, E3RA, Inc ~Ot CAI'°h ~~--~~\ ~;~ ,, Cf IftE 'y L29I ~n 7tt ~Q`~ i Fred Ernest Rennebaum Fred E Rennebaum, L E G Senior Geologist FER/JEB Enclosures Figure 1 - Location Map Figure 2 - Site & Ezploratron Plan James E Brigham, P E Principal Engineer Test Pit Logs TP-1 and TP-2, SL-1 tluough SL-10, and SP-1 through SP-5 14 G?j-lo-o October 15, 2004 T04155 / Yelm Junior High School ' Depth (feet) 1 1 Test Pn TP-1 E3RA, Inc TEST PIT LOGS Material Description Locanon South of proposed Tumor High School Approxcmate ground surface elevation Unlmown 0 0- O S 8 inches Sod and Topsoil 0 5 - 1 5 Medmm dense, damp, black, silty, gravelly SAND with abundant cobbles (Glacial Outwash with Volcanic Ash) (SM) 1 5 - 9 5 Dense, damp, fight brown, sandy GRAVEL wnh some/trace silt and abundant cobbles, lens ofgravelly sand at 6 feet (Glacial Ourivash) (GP) Test pn terminated at approxunately 9% feet on July 2, 2003 Slight to moderate caving I % to 9% feet No ~oundwater encountered Test Pit TP-2 LOCBtIOn North of proposed Junior High School Approxunaze ground surface elevation Unknown 0 0- O S 8 inches Sod and Topsoil 0 5 - 1 5 Medium dense, damp, black, silty, gravelly SAND with abundant cobbles (Glacal Outwash with Volcanic Ash) (SM) 1 5 - 9 0 Dense, damp, fight brown, sandy GRAVEL wnh some/trace silt and abundant cobbles, (Glacial Outwash) (GP) Test pn terminated at approxunately 9 feet on July 2, 2003 Moderate caving 1 % to 9 feet No groundwater encountered Sample No 1 October 15, 2004 T04155 / Yeim Junior High School E3RA, Inc TEST PTT LOGS ' Depth (feefl Material Descrtahon ' Test Pd SIrl Location Southeast ofplanned school building 1 Approxunate ground surface elevation Unknown 0 0- O S 4 inches Gravelly Topsoil and Sod 0 5 - I 0 Medmm dense, damp, black, silty, sandy GRAVEL with some cobbles (Glacial Outwash ' with Votcamc Ash) (GM) 1 0 - 9 0 Medium dense, damp, fightgrey-brown, sandy GRAVEL w~tlt trace silt and abundant cobbles (Glacial Outwaslt) (GP) ' Test prt terminated at approximately 9 feet on October 4, 2004 Moderate caving I tog feet No groundwater encountered Test Pd SL-2 Location East of planned school bmldtng Approxmrate ground surface elevation Unknown 0 0 - I 5 16 inches Gravelly Topsoil and Sod L 5 - 15 5 Medmm dense, moist, black, silty, sandy GRAVEL with some cobbles (Fill)) (GM) 15 5 - 16 5 Medium dense, damp, light gray-brown, sandy GRAVEL wRh trace silt and abundant cobbles (Glacial Outwash) (GP) Test pit terminated at approximately 16%z feet on October 4, 2004 No caving observed No groundwater encountered Sample No 1 t October 15, 2004 T04155 / Yelm Junior High School TEST PIT LOGS E3RA, Inc Death (feet) Material Descriotwn Test Prt SL-3 Location South of east part of planned school building Approxunate ground surface elevation Unknown 0 0- O S 6 inches Topsoil and Sod 0 5 - 1 0 Soft, damp, black, SILT with some gravel (Volcanic Ash) (ML) 1 0 - 3 0 Medium dense, damp, light brown, sandy GRAVEL with trace silt and abundant cobbles (Weathered Glacial Outwash) (GP) 3 0 - 9 0 Medium dense to dense ,damp to moist, fight gray-brown, sandy GRAVEL with trace stlt and abundant cobbles (Unweathered Glacial Outwash) (GP) Test prt terminated at approximate]y 9 feet on October 4, 2004 Slight caving 1 to 9 feet No groundwater encountered Test Pit SL-4 Location North of east part of planned school budding Approxunate ground surface elevation llnlmown 0 0 - 1 0 Topsoil and Sod 1 0 - 2 0 Soft, damp, black, SILT with same gavel (Volcanic Ash) (ML) 2 0 - 7 0 Medium dense, damp, fight brown, sandy GRAVEL with trace silt and abundant cobbles (Weathered Glacial Outwash) (GP) 7 0 - 10 0 Medium dense to dense, damp to moist, fight gray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacia] Outwash) (GP) Test pit terminated at approximately 16% feet on October 4, 2004 Moderate to severe caving 2 to 10 feet No groundwater encountered Samate No 1 ' October 15, 2004 E3RA, Inc T04155 / Yelm Junior High School TEST PYT LOGS Depth (feet) Material Descriphon Sample No t Test Pit SL-5 Locanon Central part of planned school building ' Approximate ground surface elevation Unknown 0 0- O S 8 Inches Topsoil and Sod 0 5 -1 5 Soft, damp, black, SILT wnh some gravel (Volcanic Ash) (ML) 1 0 - 5 0 Medmm dense, damp, bent brown, sandy GRAVEL with trace silt and abundant cobbles ' (Weathered Glacial Outwash) (GP) 5 0 - 10 0 Medmm dense to dense, damp to moist, light gray-brown, sandy GRAVEL with trace silt S-1 and abundant cobbles (Unweathered Glacial Outwash) (GP) ' Test prt terminated at approxmtately 9 feet on October 4, 2004 Sitght to moderate caving 2 to 10 feet 1 No groundwater encountered Test Pit SL-6 Locanon North of central part of planned school bmldmg Approxunate ground surface elevation Unknown ' 0 0- O S 8 niches Topsml and Sod 0 5 - 1 5 Medium dense, damp, black, silty, sandy GRAVEL wnh some cobbles (Vo]camc Ash 1 0 - 5 0 mixed with Glactal Outwash) (GM) ' Medium dense, damp, fight brown, sandy GRAVEL with Mace silt and abundant cobbles 5 0- ]0 0 (Weathered Glacial Outwash) (GP) Medmm dense to dense, damp to mmst, hghtgroy-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glaaal Outwash) (GP) Test prt terminated at approximately ] 0 feet on October 4, 2004 Slight to moderate caving 2 to 10 feet No groundwater encountered 1 October 15, 2004 T04155 / Yelm Junior High School Ll 1 E3RA, Inc TEST PIT LOGS Depth (feet) Material Descrtahon Test Pit SLr7 Location North of central part of planned school building Approximate ground surface elevation Unlmown 0 0- O S 8 inches Topsoil and Sod 0 5 - 1 5 Medium dense, damp, black, silty, sandy GRAVEL with some cobbles (Volcanic Ash mixed with Glacial Outwash) (GM) 1 0 - 5 0 Medium dense, damp, fight brown, sandy GRAVEL with trace silt and abundant cobbles (Weathered Glacial Outwash) (GP) 5 0 - 12 0 Medmm dense to dense, damp to moot, hghtgray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacial Outwash) (GP) Test pu terminated at approximately 12 feet on October 4, 2004 Moderate cavmg 2 to 12 feet No groundwater encountered Samale No Test Pd SL-8 Location West of planned school building Approxmiate ground surface elevation Unknown 0 0 - 2 0 Topsoil and Sod 2 0 - 4 0 Soft, damp, black, SILT with some gravel (Volcanic Ash) (ML) S-I 4 0 - 7 0 Medium dense, damp, fight brown, sandy GRAVEL with trace silt and abundant cobbles (Weathered Glacial Outwash) (GP) 7 0 - 10 0 Medium dense to dense ,damp to moist, tight gray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacial Outwash) (GP) Test pit terminated at approxunately ] 0 feet on October 4, 2004 Moderate cavmg 4 to 10 feet No groundwater encountered 1, October 15, 2004 1 T04155 /Yelm Junior Htgh School E3RA, Inc TEST PIT LOGS 1 Depth (feet) Matenal Descnpdon Test Pit SL-9 Location South of westpart of planned school bwldmg, m bus lane ' Approximate ground surface elevanon Unknown 0 0 - 1 5 16 mches Topsoil and Sod 1 5 - 3 5 Medwm dense, damp to moist, black, silty, sandy GRAVEI with some cobbles (Volcanic ' Ash mixed with Glacial Outwash) (GM) 3 5 - S 0 Medmm dense, damp, light brown, sandy GRAVEL with trace silt and abundant cobbles (Weathered Glacial Outwash) (GP) ' S 0 -10 0 Medium dense to dense ,damp to moist, fight gray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacial putwash) (GP) Test prt tenninated at approxinately 10 feet on October 4, 2004 Moderate caving 4 to 10 feet 1 No groundwater encountered Test Ptt SL-IO Location 5 feet west of east edge of planned school building Approxunate ground surface elevahon Unknown 0 0- 0 5 4 mches Gravelly Topsoil and Sod 0 5 - 8 0 Medium dense, moist, black, silty, sandy GRAVEL with some cobbles (Fill)) (GM) 8 0 - 9 0 Medium dense, damp, fight gray-brown, sandy GRAVEL wdh trace sdt and abundant ' cobbles (Glacutl Outwash) (GP) Test pit tenninated at approxunately 9 fee[ on October 4, 2004 No caving observed 1 No groundwater encourtered Test Pit SP-t Location Northwest part south infiltration pond Approxunate ground surface elevation Unknown 0 0 - 1 0 14 mches Sod and Topsoil ' 1 0 - 3 5 Loose, moist, brown silty SAND (SM) 3 5 - 4 5 Dense, damp, light brown, gravelly SAND with some silt (SP-SM) 4 5 - 9 0 Dense, damp, fight gray brown, gravelly SAND with some silt, abundant cobbles and ' scattered boulders, partially cemented (Glacial Outwasht) (SM) 9 0-10 0 Very dense, wet to saturated, gray-blue, silty, gravelly SAND with some cobbles (Glacial Drift) (SM) ' Test prt terminated at approximately 10 feet on October 4, 2004 No caving observed 1 No groundwater encountered Sample No S-1 1 ~I J October 15, 2004 7041551 Yelm Junior High School TEST PIT LOGS E3RA, Inc Depth (feet) Matenal Descn tton Test Ptt SP-2 Location Southwest pate south mfiltratton pond Approxunate Bound surface elevation Utilmown 0 0 - I 0 Topsoil ad Sod 1 0 - 2 5 Loose to medium dense, damp, light brown, silty, sandy GRAVEL wrth some cobbles (Weathered Giactal Outwash) (GM) 2 5 - 3 5 Dense, damp, fight brown, sandy gravel with some/trace sdt, abundant cobbles, and scattered boulders (Weathered Glacial putwash) (GP) 3 5 - 7 0 Dense, damp, light gray, sandy gravel with trace silt, abundant cobbles, and scattered boulders (Unweathered Giactal Ourwash) (GP) 7 0 - 11 0 Donse, wet to saturated, hgbt gray, silty sandy GRAVELwtth abundant cobbles {Giactal Outwash) (GM) Test pit tetmmated at approximately 11 feet on October 4, 2004 No cavmg observed Slow seepage 8 to I 1 feet Test Prt SP-3 Location Southeast part south mfiltraUon pond Approxunate ground surface elevation Unknown ~ 0 _ ~ 0 Soft, damp, black, SILT with some gravel (Volcanic Ash) (ML) Dense, damp, black, silty, sandy GRAVEL with abundant cobbles (Volcanic Ash and Giactal Outwash) (GM) 2 5 - 7 5 Medium dense to dense, damp, tight gray, sandy gravel with trace silt, abundant cobbles, and scattered boulders (Unweathered Giactal Outwash) (GP) Test pit termmated at approxmtately 7'h feet on October 4, 2004 due to refusal on bedrock or severaliarge boulders Slight cavmg 2 to 7 feet Moderate to rapid seepage at 7'/z feet Sample No October 15, 2004 T04155 / Yelm Junior High School t Depth (feet) 1 Test Pit SP-4 t 00 -10 ]0 -25 ' 25 -35 35- 130 1 ' 00-10 10-25 ' 25-35 35-120 Logged by FER 1 TEST PIT LOGS Material Descnption Location South part north infiltration pond Approxunate ground surface elevation Unknown 14 inches Sod and Topsoil Meditun dense, damp, fight brown, silty, sandy GRAVEL wIIh some cobbles (Weathered Glacial Outwash) (GM) Medmm dense to dense, damp, light brown, sandy GRAVEL with trace silt (Weathered Glacial Outwash) (GP) Medmm dense to dense, damp, hghtgray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacial Outwash) (GP) Test pit terminated at approxunately 13 feet on October 4, 2004 Moderate caving 3 to 13 feet No goundwater encountered Test Pd SP-5 Locarion North part north uifiltrapon pond Approxunate ground surface elevation Unlmown Sod and Topsoil Medium dense, damp, black, silty, sandy GRAVEL with some cobbles (Glacial Outwash with Volcanic Ash) (GM) Medmm dense to dense, damp, fight brown, sandy GRAVEL with trace silt (Weathered Glacial Outwash) (GP) Medium dense, damp, tight gray-brown, sandy GRAVEL with trace silt and abundant cobbles (Unweathered Glacial Outwash) (GP) Test pit termutated at approximately 12 feet on October 4, 2004 Severe cavmg 2 to 12 feet No groundwater encountered E3RA, Inc Sample No 1 1 1 1 _ -- Y _ ,~, ~~\ ~ o ~ t y - 949 ruj `~ Z e 1 l O I~ ~ ~ I \ O ~,~ \ ~y°,a~4~ o I ~\ i ~ , i j \ i 4 ~~ , I ` ~ , ~4. ~ ~ i ~a ! 9 .~ i ~ ~ i ,, AThj~ncLFields ~ 0'90 , ~ ' ~ ® Jam. ~ iO ~ I { '~. Yelm ~ r ~ / ' Golf Course /,~ Park ~' , \` ~ ,j ' .\ ~ ~ ///~^ " - o D ~ ~~ a ^'~ ~ ` I`_ Athleec Feld 7 I /. f ~ i P ~ ~ t, ~ i i I ~ m T ~ / II ~ ¢ JC' Co~nersLLOe~~• I ~~~~~n f ~_-_- ®® ~_ - - L'_~ ~ /® ' i GRINDf _ ROAD ' ® ~ ®® I ~ A®® _ _ I p I ~ i I ~ 9~0 ~~ I -~Hammersm/th it g„oi~ ~ i ~ ®® '~ I H//` ~ , i gthleLC Reld ~ _ _-__-_ _ - _-_ -_ __ __ _ ___--_- ~_ _- I ~- - _ _ ~_ / I ' I e62 ~~~ 395x ' ~ ~ , ' j ~ ._~ -~' h , 1 I -- - a ~~~ - Cc I ~ i , - Ii -~ " - ~ ,_ -- 1 i~ ' rt - - , I - - ~~ I~ iE i ~~ ~~' Pn Cad V ~ ~ I i p 2,000 MAP SCALE = 1 2000 K E3RA YELM JHS GEOTECHNICAL REPORT FIGURE PO BOX 44890 TOPOGRAPHIC AND LOCATION MAP 1 Tacoma, Washington 98444 YELM, WASHINGTON 1 1 1 APPElo1DIX ~ Caleulati®ns and Ilyd~aulic Analysis ~1 ~ ® ~ ~ r ~ ® ~ ~ ~ s s ~ YELM HIGH JUNIOR SCHOOL DRAINAGE DESIGN CALCULATIONS DDECM (Drainage Design and Erosion Control Manual for Thurston County WA) INFILTRATION VOLUME RE-DEVELOPED School Site 30 8 Acres Existing Percent Impe rvious 15 SCS Mapping Sod Type Spanoway Gravely Sandy Loam 0-3 % Slopes Type B Table D 2 -Residential - 20% impervious Curve Number for Type BSoil - 82 - 4 13 inches of runoff Curve Number for Impervious - 98 - 5 91 In of Runoff Existing Impervious Areas Treated Impervious Areas 201 247 SF = 4 62 Acres Total 4 62 Acres Exisifng Pervious Areas Pervious Area Tributary to Mill Pond School 205 600 SF = 5 01 Acres Pervious Area not Tnbutary to Mill Pond School 917 630 SF = 21 07 Acres Total 26 08 Acres Total Existing Area 30 70 Acres Existing Percent Impervious = 4 62/30 7 = 15 1 POST-DEVELOPED Table D 2 -Residential - 65% impervious Curve Number for Type BSoil - 94 - 4 99 inches of runoff Curve Number for Impervious - 98 - 5 91 In of Runoff Proposed Disturbed Areas Proposed Imperviuos Areas Existing Mill Pond Impervious 201 247 SF = 4 62 Acres New 172 504 SF Parking Lot Fire Lane Access Road = 172 504 SF = 3 96 Acres New 98,446 SF School Bwlding = 98 446 SF = 2 26 Acres New 1 800 SF Storage Shed = 1 800 SF = 0 04 Acres - Total Impervious Areas Junior High School 6 22 Acres Total Impervious Areas on site 10 88 Acres Proposed Disturbed Pervious Areas New 150 803 SF Track Soccer Football Field = 150 803 SF = 3 46 Acres New 87,010 SF Softball Fields Pervious Areas = 87 010 SF = 2 00 Acres Total 5 46 Acres Total Disturbed Area 16 34 Acres Proposed Undisturbed Pervious Areas Pervious Area Tributary to Mill Pond School 205 600 SF = 5 01 Acres Pervicus Area Tributary to New Junior High School 424 278 SF = 9 35 Acres Total 14 36 Acres Total Site Area 30 70 Proposed Percent Impervious =10 88/30 7 = 35 4 a~ ® ~ ~ ~ ~ ~ ~ _ ~ _ ~ ® ~ ~ ~ tl~ ~ YELM HIGH JUNIOR SCHOOL DRAINAGE DESIGN CALCULATIONS VOLUME SIZING FOR NEW JUNIOR HIGH SCHOOL INFILTRATION VOLUME PER OESlGNEO INFILTRATION RATE Per Appendix D Pre -Developed [(4 13 in/12 in/ft)(21 07 Acre)(43 560 SF/Acre)] = 315,818 CF Post Developed [(4 13in//12in/ft)(9 35Acre)(43 560 SF/Acre)]+ [(4 99in/12 in/ft)(5 46Acre)(43 S6SF/Acre)]+ [(5 91iN12m/ft)(6 22Ac)(43 560sf/AC)j= 372 508 CF Infiltration Volume Required = Post Develop -Pre Developed = 372 508 - 315 818 = 56 690 CF Minimum Infiltration \Volume = 56 690 CF MINIMUM STORAGE VOLUME PER DESIGNED INFILTRATION RATE Using a conservative Infiltration Rate of 10 in/hr 10 0 in/hr Per DDECM Pg 4-5 @ mftltration rate of 10 m/hr Minimum Storage Volume Required Per Acre of Disturbed Pervious = 1 714 CF/Ac Minimum Storage Volume Requred Per Acre of Impervious Pervious = 5,143 CF/Ac (1 713)(14 81) +(5 143)(6 22) = 57 374 CF Minimum Storage Pond Volume = 57 374 CF BUS PARKING LOT, FIRE LOOP, AND PARKING LOT Total Area = 745 747 SF = 17 12 Acres Per HYDRA the runoff volume = 63122 cf Total volume provided = 64000 cf > 63 12 2cf OK Bottom area = 32000 sf Using 10 in/hr over a 45 000 sf Bottom Infiltration Rate = 7 41 cfs MILL POND ELEMENTARY SCHOOL INFILTRATION GALLARY SIZING Per HYDRA the runoff volume regwred = 28402 cf Drywell size 32T long, 25' wide 6 deep = 47088 Use a 5 - 325' Long48" Diameter Perforated Pipe, Area = 20410 cf Trench Volume Requrred Outside of Pipes = 26678 cf x 30% voids = 8003 cf Use a 5 - 325' Long48" Diameter Perforated Pipe Area = 20410 cf Total volume provided 26413 cf Bottom area =327' x 25 = 6175 sf Using 10 in/hr over a 8175 sf Bottom Infiltration Rate = 1 69 cfs e A ~ ~ ~ ~ JOB YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN REM --- 100 YEAR STORM EVENT FOR DETENTION SIZING ' TOT 6 15 FIL C \HYE\lA INC REM FILE C \HYDRA\CMD\YELMJHS CMD ' NEW STORMWATER SIZING REM THIS FILE CREATES STORMWATER RUNOFF FLOWS GENERATED REM DURING THE 100 YEAR 24 HOUR EVENT FOR STORAGE FOR THE REM YELM JUNIOR HIGH SCHOOL CIVIL IMPROVEMENTS STORMWATER e REM THE METHODOLOGY IS CONSISTANT WITH THE 1992 STORMWATER REM MANUAL FOR THE PUGET SOUND BASIN REM THERE IS 30 80 ACRES WITHIN THE BOUNDARY OF THE REM HIGH SCHOOL IMPROVEMENTS THE PROJECT IS DIVIDIED INTO REM 8 ZONES THE STORMWATER FROM THE ZONES IS CONVEYED TO REM EITHER SWALES OR A VORTECHNICS TREATMENT DEVICES THIS REM MODEL SIZES TREATMENT DEVICES AND SWALE AND THE INFILTRATION REM GALLERIES TO MEET THE 1992 DOE MANUAL FOR THE PUGET SOUND REM BASIN USING THE 100 YEAR - 29 HOUR EVENT DPD 0 009, 4, 2, 2, 0 O1, 0 001, 0 9 CHD 6, 0 3, 0 03, 3, 8, 3, 1 0, 0, 0, 0, 0 SCS 21 07, 0 353, 98, 68, 20, O1, 523 INL 99 ' CHA 100, 344, 342 5, 342 1, 341 HOL CB1 ' NEW INFILTRATION GALLARY REC CB1 RED (0/7 41, 69000/7 91) RES 323, 323, 327, OVER ' END 1 e t 1 t 1 1 C \HYDRA\CMD\ HYDRA Version 5 85 7 w morrissette & associates Page 1 ------------------------------------------------------------------- C \HYDRA\CMD\YELMJHS CMD 9 49 15-Oct-104 CFS YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN *** STORMW Long Link Slope 1 100 0 0110 1TER SIZI Invert Up/Dn 342 10 391 00 Lateral Lateral NG Surf EreHrd Width Up/Dn Up/Dn Depth 392 71 1 3 11 63 391 60 0 9 0 60 length= 100 length= 0 *** INFILTRA Cost Link Exfil 3 0 0 PION GALLARY Invert ---------- Up/Dn(Ovr 323 00 Incoming 323 00 Discharge 327 00 Overflow Stored Channel Shape San Sto Flow Estrmated L/C/R Inf Mis Vel Cost 3 000 0 00 19 50 19 50 0 8 00 0 00 0 00 3 29 3 000 Froude Number = 0 81 Upstream length= 100 Upstream length= 0 Reservoir -- Maximum Flow Val ues ----- -------- ---- San Inf Sto Mis Design 0 00 0 00 19 50 0 00 19 50 0 00 0 00 7 91 0 00 7 91 0 00 0 00 0 00 0 00 0 00 0 0 63122 0 63122 5 C \HYDRA\CMD\ HYDRA Version 5 6 ~ w morrissette & associates Page 1 1 C \HYDRA\CMD\YELMJHS CMD _______________________________ __________ _____________~_________ 9 ____=________ 94 15-Oct-104 NONE 1 Status of DEFAULTS at start of run I Command file C \HYDRA\CMD\YELMJHS CMD I Input units are read as USA I Warnings are turned OFE I Output sent to display Detailed I Output sent to printer Off I Output sent to file Verbose I Paper width in inches 8 000 I String to reset printer 27 51 36 18 t I String to set printer to compressed 17 15 J String to set printer to 8 lines/inch 8 27 51 27 I Name of printer Epson, FX series ' I Print heading at top of page ON I I Number of steps rn hydrograph 166 I Step length in minutes 60 I Significant flow in hydrograph 0 010 I Infiltration Diurnahzation Factor 0 980 I Maximum plot value Selected by HYDRA I Type of hydrographic plot Compact I I Sanitary flow by Diurnal Curve I Delay to start of actual storm 0 00 ' Rational Method computations OFF I SCS computations Santa Barbara I Continuous simulation computations ON I Maximum d/D for pipe design/analysis I 0 900 I Match point position on pipe 0 00 or Invert I Number of allowable dram drops 999 I Mimimum drop thru manhole 0 000 ' I Manning's n Variable I Routing technique Quick I Calculate sanitary flows ON 1 I Calculate infiltration flows ON I Calculate misc flows ON I Listing of acceptable diameters (Changed by the PCO command) I 9 6 8 10 12 15 18 21 24 27 30 ' I 33 36 39 42 45 48 54 60 66 72 78 I 84 90 96 102 108 119 120 132 t 1 JOB YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN 2 REM - - 100 YEAR STORM EVENT FOR DET ENTION SIZING 3 9 TOT 6 15 t Total r ainfall 6 15 In ches 5 FIL C \HYE\lA INC ------START OF SUB-FILE------ t 1 1 0 t 1 t C \HYDRA\CMD\ HYDRA Version 5 BS ~ w morrissette & associates Page 3 ---------------------------------- --- - - - ---- --- ---- --- C \HYDRA\CMD\YELMJHS CMD 9 49 15-Oct-109 YELM JUNIOR HIGH SCHOOL - CIVZL IMPROVEMENT STORMWATER DESIGN 1380 0 15 1=== I I I I 1440 0 15 1=== I I I I 1500 0 00 I I I 1 1 15 6 7 B 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 RET END OF SUB-FILE ------ REM FILE C \HYDRA\CMD\YELMJHS CMD NEW STORMWATER SIZING REM THIS FILE CREATES STORMWATER RUNOFF FLOWS GENERATED REM DURING THE 100 YEAR 24 HOUR EVENT FOR STORAGE FOR THE REM YELM JUNIOR HIGH SCHOOL CIVIL IMPROVEMENTS STORMWATER REM THE METHODOLOGY IS CONSISTANT WITH THE 1992 STORMWATER REM MANUAL FOR THE PUGET SOUND BASIN REM THERE IS 30 80 ACRES WITHIN THE BOUNDARY OP THE REM HIGH SCHOOL IMPROVEMENTS THE PROJECT IS DZVIDIED INTO REM 8 ZONES THE STORMWATER FROM THE ZONES IS CONVEYED TO REM EITHER SWALES OR A VORTECHNICS TREATMENT DEVICES THIS REM MODEL SIZES TREATMENT DEVICES AND SWALE AND THE INFILTRATION REM GALLERIES TO MEET THE 1992 DOE MANUAL FOR THE PUGET SOUND REM BASIN USING THE 100 YEAR - 24 HOUR EVENT DPD 0 009, 24 CHD 6, 0 3 25 SCS 21 46, 4, 2, 2, 0 Ol, 0 001, 0 9 Mannings n 0 00900 Minimum diameter 4 00 Inches Minimum depth 2 00 Feet Minimum cover 2 00 Feet Minimum velocity 0 0100 Feet/Sec Minimum slope 0 00100 D/d 0 9000 Maximum diameter 132 00 Inches 0 03, 3, 8, 3, 1 0, 0, 0, 0, 0 0 353, 98, 94, 20, Ol, 523 Land segment 21 460 Acres Portion rmpervious 0 353 Curve number (CN) for Impervious 98 000 Curve number (CN) for Pervious 99 000 K Factor 20 000 Slope of land 0 0100 Sheet flow distance 523 000 Feet Computed concentration time 9 36 Minutes Total Time of Concentratron 4 36 Minutes Total rainfall falling on impervious 169116 57 CuFt Impervious runoff 162787 81 CuFt Portion off impervious 96 26 ~ C \HYDRA\CMD\ AYDRR Verson 5 85 morrrssette 3 w -------------- --- associates & ---'___ -__ ____--Page-_--4 - - C \HYDRA\CMD\YE _ - LMJHS ------ - CMD 9 44 15-Oct-109 YEL M J UNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN Peak CFS rainfall falling on impervious 7 72 Cu Ft/Sec Peak CFS runoff from impervious 7 11 CuFt/Sec Equivalant "C" off impervious 0 92 Total rainfall falling on pervious 309967 20 CuFt Pervious runoff 274851 73 CuFt Portion off pervious 88 67 $ Pea k CFS rainfall falling on pervious 14 16 CuFt/Sec Peak CFS runoff from pervious 12 39 CuFt/Sec 1 Equivalant "C" off pervious 0 68 Tota l rainfall falling on segment 479083 77 CuFt Total segment runoff 437639 55 CuFt Portion off segment 91 35 ~ Peak CF S rainfall falling on segment 21 88 CuFt/Sec Peak CFS runoff from segment 19 50 CuFt/Sec Equivalant "C" off segment 0 89 Hydrograph off land segment I - Impervious runoff rn CFS P - Pervious runoff in CFS T - Total runoff in CFS 0 00 5 00 10 00 15 00 20 00 ' Time +-- ------+---------+ ------- --+ ---------+ 0 0 24 0 O1 0 25 I I I I I 60 0 63 0 48 1 30 IIT I I I I ' 120 1 29 1 39 2 63 I* T i I I I 180 1 63 2 16 3 79 I IP T I I I I 240 1 98 2 95 4 93 I I P TI I I I 300 2 39 3 75 6 09 I I P IT I I I ' 360 2 94 4 92 7 86 I I P I T I I I 420 7 11 12 39 19 50 I I I I P I T I 480 4 98 7 93 12 41 I i P I T I 540 1 91 3 45 5 36 I I P T I I I 600 2 76 4 93 7 69 I I PI T I I I 660 1 74 3 15 4 88 1 2 P TI I I I 720 2 12 3 80 5 92 I I P IT I I 780 1 47 2 66 4 12 I I P T I I I I 840 1 65 2 97 4 62 I I P T I I I I 900 1 34 2 43 3 77 I I P T I I 1 I 960 1 37 2 48 3 86 I I P T I I I I ' 1020 1 10 2 DO 3 11 II P T I I I I 1080 1 14 2 07 3 21 II P T I I I I 1140 1 ll 2 02 3 14 II P T I I I I ' 1200 1 14 2 06 3 19 II P T I I I f 1260 1 12 2 03 3 15 I1 P T I I I I 1320 1 13 2 05 3 19 II P T I I I I 1380 1 12 2 04 3 16 II P T I I I I 1490 0 15 0 26 0 91 I I I I I Time +---------+---------+ ---------+ ---------+ 0 00 5 00 10 00 15 00 20 00 1 C \HYDRA\CMD\ HYDRA Version 5 85 ~ w morrissette & associates Page 5 C \HYDRA\CMD\YELMJHS CMD 9 94 15-Oct-104 YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN 26 INL 99 Inlet hydrographs 1 - Incoming hydrograph X - Exit hydrograph to system R - Pond or reservoir/1 0 00 5 00 10 00 15 00 20 00 Time +---------+---------+ ------- --+---------+ 0 0 25 0 25 0 00 I I I I I 60 1 30 1 30 0 00 I* I I I I 120 2 63 2 63 0 00 I * I I I I 180 3 79 3 79 0 00 I * I I I I 240 4 93 9 93 0 DO I *I I I I 300 6 09 6 09 0 00 I I* I I I 360 7 86 7 86 0 00 I I * I I I 420 19 50 19 50 0 00 I I I I * I 980 12 41 12 41 0 00 I I I ` I I 590 5 36 5 36 0 00 I * I I I 600 7 69 7 69 0 00 I I * I I I 660 4 88 9 88 0 00 I *I I I I 720 5 92 5 92 0 00 ! I* I I I 780 4 12 9 12 0 00 I * I I I I 890 9 62 4 62 0 00 I * I I I I 900 3 77 3 77 0 00 I * I I I I 960 3 86 3 86 0 00 I * I I I I 1020 3 11 3 11 D 00 I * I I I I 1080 3 21 3 21 0 00 I * I I I I 1140 3 14 3 14 0 00 I * I I I I 1200 3 19 3 19 0 00 I I I I I 1260 3 15 3 15 0 OD I * I 1 I I 1320 3 19 3 19 0 00 I * I I I I 1380 3 16 3 16 0 00 I * I I 1 I 1940 0 41 0 41 0 00 I I I I I Time +-------+--------+ ----- --+---------+ 0 00 5 00 10 00 15 00 20 00 27 CHA 100, 344, 342 5, 392 1, 341 Length 100 00 Feet GrUp 344 00 Feet GrDn 392 50 Feet InvUp 342 10 Feet InvDn 341 00 Feet Link number 1 NOTE Adju sti ng h ydrographs for worst case situat ion @Adding Sto int o Eve nt @Addinq Diurnal into De sign @Addinq Eve nt i nto D esi gn Average Design Flow 0 00 CuFt/Sec Storm flow (no SF) 19 500 Cuft/Sec be sign flow including SF 19 500 Cuft/Sec Combined SF 1 000 CHD Maximum velocity 6 0000 FPS CHD Minimum velocity 0 3000 FPS CHD Mannings "n" 0 0300 CHD Left side slope 3 0000 1 @Adding Sto into Event @Adding Diurnal into Design @Adding Event into Design Average Design Flow 0 00 CuFt/Sec Storm flow (no SF) 19 500 Cuft/Sec Design flow including SF 19 500 Cuft/Sec Combined SF 1 000 Hold[NUm] 1 Looking up record number 1 32 RED (0/7 41, 69000/7 41) 1 0 000 7 910 2 64000 000 7 410 33 RES 323, 323, 327, OVER Number of points on Volume/Discharge curve 2 Maximum capacity of reservoir INFINITE Inlet elevation 323 00 Feet Outlet elevation 323 00 Feet Link number 2 NOTE Ad3usting hydrographs for worst case situation C \HYDRA\CMD\ HYDRA Version 5 85 7 w morrissette & associates Page 7 C \HYDRA\CMD\YELMJHS CMD 9 44 15-Oct-109 YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN 30 NEW INFILTRATION GALLARY 31 REC CB1 Diversion hydrographs X - Time 1 0 23 0 23 61 1 30 1 30 121 2 60 2 60 181 3 82 3 82 241 4 97 9 97 301 6 12 6 12 361 7 88 7 41 421 19 50 7 41 481 12 39 7 91 541 5 35 7 41 601 7 72 7 91 661 9 89 7 41 721 5 89 7 41 781 4 13 7 91 841 9 59 7 41 901 3 75 7 91 961 3 82 5 81 1021 3 14 3 14 1081 3 21 3 21 1141 3 19 3 14 1201 3 21 3 21 1261 3 14 3 19 1321 3 21 3 21 1381 3 19 3 19 I - Incoming hydrograph rn CFS Exit hydrograph in CFS V - Volume of Reservoir in Cu Ft divided by10000 0 00 5 00 10 00 0 00 I I I 0 00 I * I I 0 00 I I I 0 00 I * I I 0 00 I *I I 0 00 I I* I 0 17 I I XI I 9 52 I V I X I 6 31 I I V X I I 5 57 * X 5 66 4 78 9 23 3 05 2 03 0 72 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 V V I V I I I * * * * V *I II I I I IX I I I I I I I * X X X x X 15 00 20 00 I C \HYDRA\CMD\ HYDRA Version 5 85 7 w morrissette & associates Page 8 --------------------------------------- -------- --- - ------- -- C \HYDRA\CMD\YELMJHS CMD 9 94 15-Oct-104 YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN 1441 0 38 0 38 0 00 I I I I I Time +---------+---------+---------+-------- + 0 00 5 00 10 00 15 00 20 00 34 35 END C \HYDRA\CMD\ HYDRA Versron 5 85 7 w morrissette & associates Page 9 ------------------------------------------ -- --- --------- C \HYDRA\CMD\YELMJHS CMb 9 99 15-Oct-109 YELM JUNIOR HIGH SCHOOL - CIVIL IMPROVEMENT STORMWATER DESIGN ------ S U M M A R Y O F A N A L Y S I S------ Run number on command file 19 Number of links 3 Number o£ hydrographs 40 Total sanitary population 0 Total sanitary area 0 00 Acres Total storm area 21 46 Acres Number of pumps D Number of reservoirs 1 Number of diversion structures 0 Number of inlets 1 Length of new pipe 0 00 Feet Length of existing pipe 0 00 Feet Length of channel 100 00 Feet Length of gutter 0 00 Feet Length of transport units 0 00 Feet Length of pressure pipe 0 00 Feet Closing DBF and NDX Files JOB YELM MILL POND ELEMENTARY SCHOOL 5TORMWATER FACILITIES REM --- 29 HOUR - 6 MONTH STORM EVENT FOR TREATMENT REM --- 29 HOUR - 100 YEAR STORM EVENT FOR CONVEYANCE TOT 6 15 REM TOT 1 79 FIL C \HYE\lA INC REM FIL C \HYDRA\CMD\YELMMP CMD REM THIS FILE CREATES STORMWATER RUNOFF FLOWS GENERATED REM DURING THE 100 YEAR 24 HOUR EVENT FOR STORAGE FOR THE REM YELM MILL POND ELEMENTARY SCHOOL RUNOFF REM THE METHODOLOGY IS CONSISTANT WITH THE 1992 STORMWATER REM MANUAL FOR THE PUGET SOUND BASIN ' REM THE SITE ZS DIVIDED INTO 10 SUBBASINS TRIBUTARY TO REM CATCH BASINS AND DIRECTED TO A BIOFILTRATION SWALE REM FOR TREATMENT AND INTO AN INFILTRATION GALLRY ' REM FOR DISPOSAL CHD 10, 0 5, 0 03, 3, 8, 3, 0, 0, 0, 0, 0 DPD 0 015, 6, 2, 1, 0 1, 0 0022, 0 9 NEW REM SCS DPI HOL REM NEW MILL POND --- ZONE 2 9 63, 0 479, 96, 68, 7, 0 015, 140 159, 369 23, 369 03, 361 58, 360 78, 10 ZONE2 --- SWALE SIZING @ 2$ SWALE CHA 377, 360, 352 46, 356 50, 348 96 NEW INFILTRATION GALLARY REC ZONE2 RED (0/1 89, 28913/1 89) RES 348 96, 3347 96, 399, OVER END t 1 1 C \HYDRA\CMD\ HYDRA Versron 5 85 ~ w morrrsset~e & associates Page 1 ----------------------------------------------------------------- ------- C \HYDRA\CMD\YELMMP CMD 7 18 1-Nov-104 CFS YELM MILL POND ELEMENTARY SCHOOL STORMWATER FACILITIES *** MILL POND Lrnk Long Slope Invert San Sto Qdes Diam Up/Dn Inf Mis Vel d/D 1 159 0 0050 361 58 0 0 6 3 6 28 18 360 78 0 0 0 0 3 79 ----------------------------0-88 Lateral length= 159 Upst *** SWALE Long Invert Surf FreBrd Width Link Slope Up/Dn Up/Dn Up/Dn Depth 2 377 356 50 356 50 3 5 B 00 0 0200 398 96 398 96 3 5 0 00 -------------------------- Lateral length= 377 -------------------------- Lateral length= 0 Depth Up/Dn Cover 1 02 2 65 3 25 ream lei Shape L/C/R 3 000 8 00 3 000 Upstream Upstream GrUp HGLUp DrffUp 369 23 362 90 -1 33 zgth= Pipe Design Gr Dn SrCh/Dlt HGLDn Estimated Dr £fDn Cost 369 03 362 10 0 1 93 159 Channel San Sto Flow Estimated Inf Mis Vel Cost 0 00 0 00 0 00 0 0 00 0 00 0 00 Froude Number = Undefined length= 377 length= 0 *** INFILTRATION GALLARY Reservoir Cost Invert -------------- Maxrmum Flow Values ---- --------- ---- Lrnk Ex£il Up/Dn/Ovr San Zn£ Sto Mrs Design 4 0 398 96 Incoming 0 00 0 00 6 28 0 00 6 28 0 3347 96 Discharge 0 00 0 00 1 89 0 00 1 89 399 00 Overflow 0 00 0 00 0 00 0 00 0 00 Stored 0 0 28402 0 28402 Lateral length= 0 Upstream length= 159 C \HYDRA\CMD\ HYDRA Version 5 85 ~ w morrissette & associates Page 1 ------------------------ -------------------------------------------- C \HYDRA\CMD\YELMMP CMD 7 18 1-Nov-104 NONE Status of DEFAULTS at start of run I Command file C \HYDRA\CMD\YELMMP CMD I Input units are read as OSA I Warnings are turned OFF I Output sent to display Detailed I Output sent to printer Off I Output sent to file Verbose I Paper width in inches 8 000 I String to reset printer 27 51 36 18 I String to set printer to compressed 17 15 I String to set printer to 8 lines/inch 8 27 51 27 I Name of printer Epson, FX series I Print headrng at top of page ON I Number of steps in hydrograph 166 I Step length in minutes 60 I Significant flow in hydrograph 0 010 I Infiltration Diurnalization Factor 0 980 Maximum plot value Selected by HYDRA I Type of hydrographic plot Compact I I Sanitary flow by Diurnal Curve I Delay to start of actual storm 0 00 I Rational Method computations OFF I SCS computations Santa Barbara I Continuous simulation computations ON I Maximum d/D for pipe design/analysis 0 900 I Match point position on pipe 0 00 or Invert I Number of allowable dram drops 999 I Mimimum drop thru manhole 0 000 I Manning's n Variable I Routing technique Quick I Calculate sanitary flows ON I Calculate rnfiltratron flows ON I Calculate misc flows ON I Listing of acceptable diameters (Chang ed by the PCO command) I 4 6 8 10 12 15 18 21 24 27 30 I 33 36 39 42 45 48 54 60 66 72 78 I 89 90 96 102 108 119 120 132 1 JOB YELM MILL POND ELEMENTARY SCHOOL STORMWATER FACILITIES 2 3 REM --- 24 HOUR - 6 MONTH STORM EVENT FOR TREATMENT 9 REM --- 24 HOUR - 100 YEAR STORM EVENT FOR CONVEYANCE 5 6 TOT 6 15 Total rainfall 6 15 Inches 1 ' C iHYEa2AiCMB\ HYDRA Vezsr on 5 85 1 w morrissette 6 associates Page 3 1 _________ _______________________________________________ ___ _________________ __ C \HYDRA\CMD\YELMMP CMD 7 18 1-Nov- 109 YELM MILL POND ELEMENTARY SCHOOL STORMWATER FAC ILITIES 1140 0 15 1=== I I I I 1200 0 15 1=== I I I I 1260 0 15 1=== I I I I 1320 0 15 1=== I I I I 1380 0 15 1=== I I I I ' 1440 0 15 1=== I I I I 1500 0 00 I I I I I 15 RET -- - END OF SUB-FILE ------ 9 REM FIL C \HYDRA\CMD\YELMMP CMD 10 11 REM THIS FILE CREATES STORMWATER RUNOFF FLOWS GENE RATED 12 REM DURING THE 100 YEAR 29 HOUR EVENT FOR STORAGE FOR THE 13 REM YELM MILL POND ELEMENTARY SCHOOL RUNOFF ' 14 REM THE METHODOLOGY IS CONSISTANT WITH THE 1992 ST ORMWATER 15 REM MANUAL FOR THE PUGET SOUND BASIN 16 17 REM THE SITE IS DIVIDED INTO 10 SUBBASINS TRIBUTAR Y TO 16 REM CATCH BASINS AND DIRECTED TO A HIOFILTRATION S WALE 19 REM FOR TREATMENT AND INTO AN INFILTRATION GALLRY 20 REM FOR DISPOSAL 21 CHD 10, 0 5, 0 03, 3, 8, 3, 0, 0, 0, 0, 0 22 DPD 0 015, 6, 2, 1, 0 1, 0 0022, 0 9 Mannings n 0 0150 Minrmum diameter 6 00 Inches Minimum depth 2 00 Feet Minimum cover 1 00 Feet Minimum velocity 0 10 Feet/Sec Minimum slope 0 00220 D/d 0 9000 Maximum diameter 132 00 Inches 23 f 24 NEW MILL POND 25 26 REM --- ZONE 2 27 I 28 SCS 9 63, 0 479, 96, 68, 7, 0 015, 190 Land segment 9 630 Acres Portion impervious 0 479 I Curve number (CN) for Impervious 98 000 Curve number (CN) for Pervious 68 000 K Factor 7 000 Slope of land 0 0150 Sheet flow distance 190 000 Feet Computed concentration time 2 72 Minutes Total Time of Concentration 2 72 Minutes C \HYDRA\CMD\ HYDRA Version 5 85 ~ w morriss ette & associates Page 4 C \HYDRA\CM D\YELMMP CMD 7 18 1-Nov-109 YEL M MILL POND ELEMENTARY SCHOOL STORMWATER FACILITIES Total rainfall falling on impervious 102977 78 CuFt Impervious runoff 99103 Ol CuFt Portion off impervious 96 29 $ P eak CFS rainfall falling on impervious 4 70 CuFt/Sec Peak CFS runoff from impervious 4 45 CuFt/Sec Equivalant "C" off impervious 0 95 Total rainfall falling on pervious 112007 15 CuFt Pervious runoff 49923 79 CuFt Porta.on off pervious 44 57 ~ Pea k CFS rainfall falling on pervious 5 11 Cu Ft/Sec Peak CFS runoff from pervious 1 83 CuFt/Sec Equivalant "C" off pervious 0 36 Total rainfall falling on segment 219989 93 Cu Ft Total segment runoff 149026 80 CuFt Portion off segment 69 32 ~ Pe ak CFS rainfall falling on segment 9 B2 CuFt/Sec Peak CFS runoff from segment 6 29 CuFt/Sec Equivalant "C" off segment 0 64 Hydrograph off land segment I - Impervious runoff in CFS P - Pervious runoff in CFS T - Total runoff in CFS 0 00 2 00 9 00 6 00 B 00 Time +_________+________ _+________ _+ _________+ 0 0 16 0 00 0 16 I I I I I 60 0 51 0 DO 0 51 I* I I I I 120 0 79 0 00 0 79 I* I I ~ I I 160 1 00 0 00 1 00 I * I I I I 240 1 21 0 00 1 22 I * I I I I 300 1 43 0 13 1 57 I IT I I I I 360 1 81 0 41 2 21 IP I T I I I 420 4 45 1 83 6 28 I P I II T I 480 2 55 1 36 3 91 I P I I TI I I 590 1 23 0 82 2 OS I P I TI I I I 600 1 65 1 02 2 67 I P I I T I I I 660 1 05 0 78 1 83 I PI T I I I I 720 1 30 0 88 2 18 I P I T I I I 780 0 86 0 67 1 53 I PI T I I I I 840 1 09 0 74 1 77 I PI T I I I I 900 0 78 0 63 1 91 I PI T I I I I 960 0 87 0 65 1 51 I PI T I I I I 1020 0 69 0 53 1 16 I* T I I I I 1080 0 73 0 56 1 28 I PI T I I I 1190 0 65 0 54 1 20 I* T I I I I 1200 O 71 0 57 1 28 I PI T I I I I 1260 0 66 0 56 1 22 I" T I I I I 1320 0 71 0 58 1 28 I PI T I I I I 1380 0 67 0 57 1 24 I* T I I I I 1440 0 07 0 05 0 12 I I I I I Time +---------+-------- -+-------- -+ ---------+ 1 1 1 t 1 t t i t 1 1 C \HYDRA\CMD\ HYDRA Version 5 65 7 w morrissette & associates Page 7 - C ----------------------------------------- \HYDRA\CMD\YELMMP CMD ------------ - --- - ------ 7 1B 1-Nov- -- 109 YELM MILL POND ELEMENTARY SCHOOL STORMWATER FACILITIES Nothing to plot 37 38 NEW INFILTRATION GALLARY 39 REC ZONE2 Hold[Num] 1 Looking up record number 1 90 RED (0/1 89, 28413/1 89) 1 0 000 1 890 2 28913 000 1 890 41 RRES 398 96, 3397 96, 399, OVE Number of points on Volume/Discharge curve 2 Maximum capacity o£ reservoir INFINITE Inlet elevation 348 96 Feet Outlet elevation 3347 96 Feet Link number 3 NOTE Adz usting h ydrographs £or worst case situation @Adding Sto into Event @Adding Diurnal into Design @Adding Event into Design Average Design Flow Storm flow (no SF) De sign flow including SF Combined SF Diversion hydr ograp hs I - Incoming hydrograph rn CFS X - Exit hydrograph in CFS V - Volume of Reservoir in Cu Ft divided by10000 0 00 2 00 4 00 Time +---------+---------+------ 1 0 15 0 15 0 00 I I I 61 0 52 0 52 0 00 I I I 121 0 79 0 79 0 00 I* I I 181 1 0l 1 0l o 0o I * I I 241 1 21 1 21 0 00 I * I I 301 1 58 1 58 0 00 I * I I 361 2 22 1 89 0 12 I X I I 421 6 28 1 89 1 70 I VX I I 481 3 91 1 89 2 92 I X IV II 541 2 09 1 89 2 98 I XIIV I 601 2 66 1 89 2 76 I X I IV I 661 1 82 1 89 2 73 I * I V I 721 2 19 1 89 2 84 I X I v I 781 1 53 1 89 2 71 I IX I V I 841 1 77 1 89 2 67 I * I V I 901 1 90 1 89 2 49 I I X IV I 961 1 53 1 89 2 36 I IX IV I 1021 1 16 1 89 2 10 I I XVI I 1081 1 28 1 89 1 88 I I* I I 1191 1 21 1 89 1 63 I I VX I I 0 6 6 1 00 Cu Ft/Sec 277 Cuft/Sec 277 Cuft/Sec 000 6 00 8 I I I I I I I I I I I I I I T I 00 1 1 C \HYDRA\CMD\ HYDRA Version 5 85 ' morrissette & 3 w associates ---------- ---Page----8 -- - - - - C \HYDRA\CMD\YELMMP CMD --- ------- -- ---- --- ---- 7 18 1-Nov-104 ' YELM MIL L POND E LEMENTARY SCHOOL STORMWATER FACILITIES 1201 1 28 1 89 1 41 I IV X I I I I 1261 1 23 1 89 1 17 I ` X I I I I ' 1321 1 28 1 89 0 95 I VI X I I I I 1381 1 23 1 69 0 72 I V I X I I I I 1441 0 12 1 89 0 08 I X I I I I ' 1501 0 00 0 22 0 00 I I I I I Time +------ ---+-- -------+---------+---------+ 0 00 2 00 4 00 6 00 8 00 t 92 ' 43 END 1 1 1 1 1 C \HYDRA\CMD\ HYDRA Version 5 85 ' ~ w morrissette & associates ---------------------------------- ------ - Page 9 ----------- --------- --- C \HYDRA\CMD\YELMMP CMD 7 18 1-Nov-109 YELM MILL POND ELEMENTARY SCHOOL STORMWATER FAC ILITIES ------ S U M M A R Y O F A N A L Y S I S------ ' Run number on command file 8 Number of links 4 Number of hydrographs 41 ' Total sanitary population 0 Total sanitary area 0 00 Acres Total storm area 9 63 Acres Number of pumps 0 ' Number of reservoirs 1 Number of diversion structures 0 Number of inlets 0 ' Length of new pipe 159 00 Feet Length of existing pipe 0 00 Feet Length of channel 377 00 Feet Length of gutter 0 00 Feet ' Length of transport units 0 00 Feet Length of pressure pipe 0 00 Feet Closing DBF and NDX Files 1 1 1 lJ 1 C 1 1 1 1 ~~~~~~~ ~ C®mmercgal St®rmwater Fac~fl~ties 1 1 1VI~in~enan~e Agreement COMMERCIAL/INDUSTRIAL AGREEMENT TO MAINTAIN STORMWATER FACILITIES AND TO IMPLEMENT A POLLUTION SOURCE CONTROL PLAN ' BY AND BETWEEN YELM COMMUNITY SCHOOLS ITS HEIRS, SUCCESSORS, OR ASSIGNS (HEREINAFTER "OWNER") ' AND CITY OF YELM (I~REINAFTER "JURISDICTION") ' The upkeep and maintenance of stonnwater facilities and the unplementation of pollution source control best management practices (BMPs) Is essential to the protection of water ' resources All property owners aze expected to conduct busmess m a manner that promotes environmental protection Thrs Agreement contains specific provisions with ' respect to maintenance of stonnwater facrhties and use of pollution source control BMPs LEGAL DESCRIPTION Pazcel number 217225140100, in the Crty of Yelm ' Whereas, OWNER has constructed unprovements, including but not limited to, buildings, pavement, utilities and stormwater facilities on the property descnbed above In order to further the goals of the JURISDICTION and to ensure the protection and enhancement of ' water resources, the JURISDICTION and OWNER hereby enter into this Agreement The responsibilities of each party to this Agreement are Identified below ' OWNER SHALL• (1) Implement the stormwater facility maintenance program included herein as 1 Attachment "A" (2) Implement the pollution source control program included herein as Attachment ..B.. (3) Mamtam a record (In the form of a log book) of steps taken to Implement the 1 programs referenced In (1) and (2) above The log book shall be available for inspection by Jurrsdlction staff at 101 N 1 S` Street dunng normal busmess hours ' The log book shall catalog the action taken, who took It, when It was done, how rt was done, and any problems encountered or follow-on actions recommended Maintenance items ("problems") listed m Attachment "A" shall be inspected on a monthly or more frequent bases as necessary OWNER Is encouraged to ' ' photocopy the individual checklists m Attachment "A" and use them to complete rts inspections These completed checklists would then, m combination, compnse the monthly log book ' (4) Submit an annual report to the JURISDICTION regazdmg implementation of the programs referenced m (1) and (2) above The report must be submitted on or before May 15 of each calendar yeaz and shall contain, at a minimum, the following {a) Name, address and telephone number of the businesses, the persons, or the firms responsible for plan unplementation, and the person completing the report ' (b) Tune penod covered by the report (c) A chronological summary of activities conducted to implement the programs referenced m (1) and (2) above A photocopy of the applicable sections of the log book, with any additional explanation needed, shall normally suffice For any activities conducted by paid parties not include a copy of the invoice for services affiliated with OWNER , 1 (d) An outline of planned activities for the next yeaz THE JURISDICTION SHALL ' (1) Provide techmcal assistance to OWNER m support of rts operation and maintenance activities conducted pursuant to rts maintenance and source control programs Said assistance shall be provided upon request, and as Junsdiction time and resources permit, at no charge to OWNER (2) Review the annual report and conduct a mrnunum of one (1) site visit per yeaz to discuss performance and problems with OWNER ' (3) Review this agreement with OWNER and modify it as necessary at least once every three (3) years REMEDIES. (1) If the JURISDICTION determines that maintenance or repair work is required to ' be done to the stonnwater facilities existing on OWNER, property, the JURISDICTION shall give the owner of the property within which the drainage facility is located, and the person or agent m control of said property, notice of the specific maintenance and/or repair required The JURISDICTION shall set a reasonable time m which such work is to be completed by the persons who were ' given notice If the above regmred maintenance and/or repair is not completed L within the time set by the JURISDICTION, wrtten nonce will be sent to the 1 persons who were given notice stating the JURISDICTION'S intention to perform such maintenance and bill the owner for all incurred expenses The Junsdiction may also revoke stormwater urihty rate credits for the quality component or invoke surcharges to the quantrty component o£ OWNER bill if required ' maintenance is not performed (2) If at any tune the JURISDICTION detemm~es that the existing system creates any imminent threat to public health or welfare, the JURISDICTION may take immediate measures to remedy said threat No notice to the persons listed in Remedies (1), above, shall be required under such circumstances (3) The owner grants unrestncted authonty to the JURISDICTION for access to any and all stonnwater system features for the purpose of performing maintenance or repair as may become necessary under Remedies 1 and/or 2 (4) The persons listed m (1), above, shall assume all responsibility for the cost of any maintenance and for repairs to the stormwater facility Such responsibility shall include reimbursement to the JURISDICTION within 30 days of the receipt of the 1 invoice for any such work performed Overdue payments will require payment of interest at the current legal rate for liquidated Judgments If legal action ensues, any cost or fees incurred by the JURISDICTION will be borne by the parties responsible for said reimbursements (5) The owner hereby grants to the JURISDICTION a hen against the above- ' descnbed property m an amount equal to the cost incurred by the JURISDICTION to perform the maintenance or repair work descnbed herein L~J 1 1 C~ This Agreement ~s intended to protect the value and desvabdity of the real property descnbed ' above and to benefit all the cdizens of the Jurisdiction It shall run with the land and be binding on all parties having or acqu~nng from OWNER or their successors any rights, title, or interest m the property or any part thereof, as well as their title, or mterast m the properly or any part thereof, as well as their heirs, successors, and assigns They shall more to the benefit of each present or future successor m interest of said property or any part thereof, or interest therein, and to the benefit of all citizens of the .TURISDICTION ' Owner ' Owner STATE OF WASHINGTON ) SS ' COUNTY OF THURSTON ) On this day and year personally appeared before me, and known to be the mdrv~dual(s) descnbed, and who executed the foregoing instrument and acknowledge the sazd instrument to be the 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 m and for the State of Washington, res~dmg m Dated at ,Washington, this day of , 200_ STATE OF WASHINGTON ) )SS COUNTY OF THURSTON ) On this day and year 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 Mumc~pal 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 m and for the State of ' Washington, residing m 1 APPROVED AS TO FORM ' INSTRUCTIONS FOR PERSON MAINTAINING STORMWATER SYSTEM ' The followtng pages descnbe the mazntenance needs of the stormwater conveyance, storage and disposal components of the system designed for this site This martenance effort shall be the responsrbiltty of the YELM COMMUNITY SCHOOLS or rts assigned ' representarive In general, system components should be inspected in accordance with the Maintenance Checklists included as Attachment "A" at the rear of this document Use the suggested frequency indicated on the left side of the Checklist Forms ' (1) Monthly (Ivi) from November through Apnl (2) Annually (A), once m late summer (preferably September) ' (3) After mayor storm events {S)>1 inch in 24 hours Inspectron findings should be recorded on photocopres of Mattenance Checklist forms ' Checkoff the problems you looked for each rime an inspecrion was performed Maintenance should be undertaken to correct deficrenctes found and comments on ' problems found and acrions taken entered on the forms Completed Checkhst Forms should be filed and incorporated m the annual report to be rssued m May of each year If you have specrfic questrons or requrre technical assrstance, contact the responsrble ~urrsdrerion Please do not hesrtate to call, especrally rf you are unsure whether a srtuarion you have drscovered may be a problem 1 ATTACHMENT "A" MAINTENANCE PROGRAM COVER SHEET Inspection Penod Number of Sheets Attached Date Inspected Name of Inspector Inspector's Signature L~ L~ 1 ] 1 ATTACHMENT "A" MAINTENANCE PROGRAM Maintenance Checklist for Closed Detention Systems (Pipes/Tanks) rainage System Conditions that Should Frequency Feeture J Problem Conditwns to check for Exist Plugged air vents (small pipe that One-half of the end area of a vent is Storage connects blocked at any point with debris and areas catch basin to sediment Plugged vent can cause storage Vents free of debris and M i e tank store e i e are to cotta se sediment All sediment and debns removed from storage Accumulated sediment depth exceeds 15°h area Contact City Public of drameter Example 72 inch storage tank Works for gwdance on Debris and would require cleaning when sediment sediment removal and M sediment reaches de th of 10 inches dis osal Joints between All lomts between tank/pipe Any crack allowing matenal to leak into tank/pipe sections are A section facih sealed Tank/pipe repaired or replaced to design Tank/pipe bent Any part of tank pipe is noticeably bent out Contact a professional A out of sha a of sha a en loser for evaluation Cover not in Cover is missing or only partially in place M S Manhole lace An o en manhole re wires mainlenace Manhole is closed Mechanism cannot be opened by one Locking mamtenace person with proper tools Bolts mechanism into frame have less than tl2 Inch of thread Mechanism opens with A not workm ma not ap I to self-locket IWs ro r tools One Maintenance person cannot remove lid - after applying 80 pound of IrR Intent is to Cover can be removed Cover difficult keep cover from sealing off access to and reinstalled by one A to remove maintenace maintenance arson a er meets esign Maintenance person fudges that ladder is standards and allows Ladder rungs unsafe tlue to missing rungs misalignment maintenance persons safe A unsafe rust or cracks access If you are unsure whether a problem exisis please contact the Jurisdiction ono ask for tecnnicel assistance ' Comments ' A =Annual (March or April prefered) M =Monthly (see schedule) S = After motor storms J ATTACHMENT "A" (CONTINUED) Maintenance Checkkst Por Catch Basns and Inlets t If you are unsure whether a problem exists please contact the Junsdrehon and ask for technical assistance Comments ramage System Conditions that Should Frequency Feature d problem Contlitrons to check for host No trash or debns located immetl~ately in front of Trash debns Trash or debns in front of the catch basin catch basin opening and sediment opening is blocking caparaty by more than Grate is kept clean and M S General in or on basin 10% allows water to enter Sediment or debns (m the barn) that exceeds 1/3 the depth from the bottom of No sediment or debns in basin to invert of the lowest pipe into or out the catch basin Catch M the basin basin du out and clean Trash or debns in any inlet or pipe blocking Inlet and outlet pipes tree M S more than 1/3 of its het ht of trash or debris Structural damage to Comer of frame extendes more than 3/4 frame and/or inch past curb face into the street Qf M to slab a hrable Frame rs even with curb Top slab has holes Larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all matenal is running into Top slab is free of holes M the basin and cracks Frame not srttrng flush on top slab 1 e separation of more than 3/4 inch of the Frame is sitting flush on M frame from the to slab to slab Cracks wider than 1/2 inch and longer than 3 feet any ewtlence of soil partmles Basin replaced or repaired Cracks in entenng catch basin through cracks or to design standards basin mamtanence person Judges that structure is ContaIX a professional A walls/bottom unsountl en sneer for evaluation Cracks wider than 1/2 inch and longer than 1 foot at the font of any mlet/outlet pipe or No cracks more titan 1/4 any evidence of soil particles entenng catch inch vnde at the joint of A basin throw h cracks mteUOUtfet r Basin replaced or repaired Basin nos settled more than 1 inch or has to design standards SettlemenUm rotated more than 2 inches out of Contact a professional A isali nment alt omen( en sneer for evaluation ve azar ssence o emrca s su as na ura o co or o or or s u ge or other gas oil and gasoline Obnoxious color Basin is dug out and M S pollution otlor or sludge noted clean Outlet pipe is Vegetation or roots growing m inlet/outlet dogged with pipe /ornts that rs more than srx inches tall No vegetation or root M S vegetation and less than six inches apart growth present A =Annual (March or Apnl preferetl) M =Monthly (see schedule) S =After major storms 1 ~~ CIS Maintenance Checklist for Ponds ATTACHMENT "A" (CONTINUED) ramage System Frequency Feature ~ Problem Conddions to check for Conditions that Should Exist Dumping of yard wastes such as grass clipping such as grass clippings and branches into basin Unsightly accumulation of Trash & nondegradable matenals tlebris such as glass plastic Remove trash and debns and dispose as buildup in metal foam antl coated prescnbed by Gty Waste management M 5 General and a er Section Trash rack Bar screen over outlet more Replace screen Remove trash and debris plugged or than 25 ~ covered by debns and dispose as prescnbed by Cary Waste M S missin or missin mana ement Section Remove poisonous vegetation Do not spray Any poisonous vegetation chemicals on vegetation without obtairnng Poisonous which may constitute a gmdance from the Cooperative Extension M ve elation hazard to the ubhc Servce antl a royal from the Ci Presence of chemicals such as natural gas oil and Find sources of pollution and eliminate them Frre hazard gasoline obnoxious color Water is free from noticeable color odor or M 5 or ollulion odor or stud a noted contamination For grassy ponds selectively thatch aerate and reseed pontls Grass cutting unnecessary unless didsted by aesthetics For wetland ponds hand plant nursery-grown For grassy pontls grass wetland plants in bare areas Contact the cover is sparse and weedy Cooperative Extension Service for direction Vegetation or is overgrown For on invasive speces such as purple not growing wetland pontls plants are loosestnfe and reed canary grass Pond or is sparse or invasroe species bottoms should have uniform dense M over rown are resent coves a of dewed lant s ewes Any evidence a/rodent holes rf facility is acting as a dam or berm or any evidence of water piping Rotlents destroyed and dam or bens Rodent through dam or berm via repaired Contact the Thurston County M holes rodent holes Health De adment for uitlance When isects such as wasps and hornets interfere with maintenance activities or Insects destroyed or removed from site when mosquitos become a Contact Cooperative Extension Service for M Insects nuisance uidance Tree growth does not allow maintenance access or interferes wdh maintenance activity (I a slope mowing silt removal or equipment movements) If trees are Trees do not hinder maintenance activities not interfering with access Seleciwely cultivate trees such as alders for A Tree rowth leave trees alone firewcod Check around inlets and outlets for signs of erosion Check berms for srgns of sbdm9 or settling Actwn is needetl where erroded Find causes of erroswn and ehmmate them damage damage over 2 Then slopes should be stabalized by using Erosion on inches deep and where appropriate erosion control measure(s) e g Side slopes berms or at there is potential tar rock reinforcement planting of grass M of pond __ entrance/exd continued emoson coin action 1 1 Accumulated sedimetn Uat exceeds 10% of the designed pond depth Bused or partially bused Sediment outlet structure probably Sediment leaned out to designed pontl Storage buildup in indicates srgnficant shape and depth pond reseeded if M area and sediment de osrts necessa to control emosion Any part of dike which has settled 4 inches lower than Drke should be bwtt back to the design A Pond dikes Settlements the desi n elevation elevation Only one layer of rock ewsts above native sail in Emergency area 5 square feet or larger ovefow ! Rock or any exposure to native A s dlwa missm sod Re lace rocks to desi n standards mergency i e o pon as no area overflow / Overflow wdh large rocks to handle One Time spilhvay missing emergency overflows Contact City for guidance If you are unsure whether a problem ewsts please contact the Junsdicuon antl ask for technical assistance ' Comments A =Annual (March or Apnl prefered) M = Monthty (see schetlule) ' S =After mator storms ATTACHMENT "A' (CONTINUED) Maintenance Checkbst for InflltmGOn Systems 1 ramage System Frequency Feature ~ Problem Condtions to check for Conditions that Should bast Trash &debns buildup in See Mamtenace Checklist for M S General and Ponds See Maintenance Checklist for Ponds Poisonous See Mamtenace Checklist for M ve etaGOn Ponds See Maintenance Checkbst for Ponds Fire hazard or See Mamtenace Checklist for M S ollution Ponds See Maintenance Checklist for Ponds Vegetation not grovnng or is See Mamtenace Checkbst for M ove rown Ponds See Maintenance Checklist for Ponds See Mamtenace Checkbst for M Rodent holes Ponds See Maintenance Checklist for Ponds See Mamtenace Checkbst for M Insects Pontls See Maintenance Checklist for Ponds Sediment is removed and/or facihry is A soil texture test indicetes cleaned so that infiltration system Sediment facility is not working at its works according to design A sediment Storage buildup in designed capabilities or was trapping area is installed to reduce A area s stem incortectl desi ned sediment trans on into infiltration area Additional volume is added through Storage area excavation to provide needed storage drains slowly A soil texture test indicates Sod is aerated and rotohlted to improve (more than 48 facibty is not working at ds drainage Contact the Gty for hours) or designed capabdiGes or was mformabon on ds requimments A overflows incorrect) desi ned re ardin excavation Any sediment and debns filling area to 10 k of depth from sump bottom to bottom of outlet SetlimeM pipe or obstructing flow into the M tra in area connector i e Clean out sum to desi n de th Add a trapping area by constructing a Sediment sump for settling of solids Segregate trapping area Stormwater enters infiltraGOn settling area from rest of tacihty One Time not resent area duectl wdhout treatment Contact Ci for mdance y visual inspection ittle or no Sediment and water flows through filter dunng M Rock filters debns heavy rain storms Replace gravel in rock filter If you are unsure whether a problem exists please contact the Junsdiction and ask for technical assistance ' Comments ' A =Annual (March or April prefered) M =Monthly (see schedule) S =After mator storms 1 1 1 ATTACHMENT "A' (CONTINUED) Maintenance Checklist for Energy Disslpators t ralnage System Frequency Feature ~ Problem Conditions to check for Condrtrons that Should Exrst Only one layer of rock exists above Missing or the natural Boll in area 5 square moved feet or larger or any exposure to A Rock ad rock native soil Re face rocks to desi n standards Rock filled trench for Missing or tlischarge moved large rock (30 16 Each) so that rock is A from ontl rock Trench is not full of rock visible above etl a of trench Prpe ~ plugged Dipersion wdh Accumulatetl sediment that M trench sediemtn exceeds 20% of the desi n de th PI a cleanedlflushed Perforation Over 712 of perforations m pipe are M s lu ed lu ed with tlebns and sediment Clean or re lace ertorated i e Visual evidence of water discharging at wncentrated points Not along Vench (normal contldlon is a dischargin sheet flow of water along trench) Trench must be retlesigned or or rebuil g water Intent is to prevent erosion to standard Elevation of lip oftrench M S ro ed dama a should be the same flat at all oinis Water flows out Maintenance person observes top of water flowing out dunng any storm disinbutor less than design storm or it is Facility must be rebuilt or redeslgned to catch causing or appears likely to cause standards Pipe is prohably plugged or M S basin tlama a dama ed and needs re lacement Receiving area Water in recerwng area rs causing Stabilise slope wdh grass or other oversalura or has potential of causing vegetation or rock if contldlon is M 5 fed landslide severe If you are unsure whether a problem exists please contact the uunsaicuon ana asx ror [ecnmcai assistance ' Comments K~ A =Annual (March or Apnl prefered) M =Monthly (see schedule) S =After mator stones 1 1 1 t ATTACHMENT"A" MAINTENANCE PROGRAM Maintenance Cheddist for Conveyance Systems (Pipes Ditches and Swalea) 1 J 1 1 1 ~~ Drainage System Frequency Feature d Problem Contlibona ro check for Condfuona that Should Ewst Sediment& Aocumulatetl Sediment that exceeds M S Pi es Debris 20%of the diameter of the pipe Pi a dearred of aA sediment end debns Vegetation that reduces free All vegetation removed 5o water flows Ireery M VegetaUan movement of water Nrough pipes Nrough pipe Damaged Protective coating is damaged rust is mated bent rousing more than 50%detenorahon or crushed ban art of the pipe Pipe is repaired or re laced Any dent that eigmfcantly impedes flow lie decreases the cross section M area of plpe 6y more than 20%) Pipe repaired or replaced Dumping aF yaM wastes ouch as greas dlppmga and brenches into beam Unalghtly accumula4on of nontlegreda6le matenels such as Remove trash end debns end dispose of as Open glass plastic metal main end coated deathbed by City Waste Management M S ddches Tresh 8 Debns paper Section Sediment Axumulated sediment that exceeds Ddch tleared of all sediment and debns st M buildup 20% of the design OepN that it matches design Vegetation (e g weedy shmbs or saplings) that reduces free Water flows freely through ditches Grassy Vegetallon movements of water through dittoes vegetation should ba left alone Erosion damage to M slopes See Ponds Checklist Sea Ponds Checklist Rock lining out of place ar missing (rf Maintenance person ten see heave ' aD livable) sml beneath the rock lining Replace rocks to desi n standard etch enas Basins See Catch Bas+ns checklist See Catch Basins checklist M S Swales Tresh 6 Dabns See above for Ditches See above tar Ddches Sediment & Vegetauon may need to be replanted after M Debns See above for Ditches deaning Aerate sods and reseed and muldt bare areas Maintain grass height at a mimmum Vegetation not Grass cover is sparse end weedy or 8 inches For bast stormwater treatment grovnng or areas era overgrown with woody Remove woody growth rewntour and M overgrown vegetation reseed as necessary Erosion damage to M S slopes See Ponds Checklist Sea Ponds Checklist Conversion by If possible speak with homeowner and trornetWnBf W reg4aal that Swale area ba reafered Dontad imcempatible Swale has been filled in or bbckad by Ciry to report problem rf not rectified M use shed woodpile shmbbery etc vduntanly A survey may 6e needed to check grades Gredes need to be In 1 5% renge rf possible Swale does Water stands in Swale or flmv veloury If grade is less than 1 % undeMrems may A not drew is vary slow Stagnation occurs need to ba installed If you are unsure whether a problem ewsts please muted the Junsdidwn end ask for technical essrstarice ' Comments K~ A =Annual (March or Apnl prefered) 1 M =Monthly (see schedule) S =Alter motor storms ' ATTACHMENT "A" (CONTINUED) Maintenance Checklist for Fenang/Shrubbery Screen/Other Landscaping 1 1 ramage System Frequency Feature J Problem Conditions to check for Conditions that Should Exist Missing or broken partts/dead Any defect in the fence or screen Fence is mended or shrubs replaced to M General shrubbe that permits easy entry to a facility form a solid barrier to ent Erosion has resulted in an opening under a fence that allows entry by Replace sod under fence so that no M, S Erosion people or pets opening exceeds 4 inches in height Shrubbery is trammed and weeded to Unruly Shrubbery is growing out of control provide appealing aesthetics Do not M vegetation or is infested with weeds use chemicals to control weeds Damaged Posts out of plumb more than 6 Posts plumb to within 11/2 inches of A parts inches plumb Top rod free of bends greater than 1 A Top rails bent more than 6 inches inch Any part of fence (including posts, top rails, and fabric) more than 1 Fence is aligned and meets design A foot out of design alignments standards A Missing or loose tension wire Tension wire in place and holding fabric Missing or loose barbed wire that is sagging more than 21/2 inches Barbed wve m place with less than 3/4 A between posts inch sag between posts Extension arm missing, broken, or bent out of shape more than 11/2 Extension arm in place with no bends q inches larger than 3/4 inch Detenorated paint or Part or parts that have a rusting or protective scaling condition that has affected Structurally adequate posts or parts with A coating structural adequac a uniform protective coating penings in a ric are suc tat Openings in an flinch-diameter ball could fit M fabric through No openings in fabric ' If you are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance Comments A =Annual (March or April prefered) M =Monthly (see schedule) S =After motor storms 1 1 1 ATTACHMENT "A" (CONTINUED) Maintenance Checklist for Gates 1 t Ll remage System Frequency Feature ~ Problem Conditions to check for Conditions that Should Exist Pond has a functioning gate to allow entry of people and maintenance egwpment such as mowers and Damaged or backhoes If a lock is used, make sure missing Gate is broken lammed, or City Stormwater Section field staff have M General components missing a key Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance Hinges intact and tubed Gate is M person working freely Gate is out of plumb more than 6 inches and more than 1 foot out of q design alignment Gate is aligned and vertical Missing stretcher bar stretcher A bands, and ties Stretcher bar, bands ,and ties in place If you are unsure whether a problem exists, please contact the .lunsdicnon and asK Tor tecnnicai assistance Comments 1 A =Annual (March or April prefered) M =Monthly (see schedule) S =After major storms 1 ' ATTACHMENT "A" (CONTINUED) Maintenance Checklist for Grounds (Landscaping) (structure that controls rate at which water exits faaldy) t 1 1 l Drainage System Frequency Feature ~ Problem Conditions to check for Conditions that Shall Exist Weeds Weeds growing in more than 20% of the Weeds present in less than 5% of the M General (nonpoisionous) landsgped area (trees antl shrubs only) landscaped area Any presence of poision roy or other No poisionous vegetation or insect M Safety hazard poisionous vegetation or insect nests nests present in the landscaped area M,S Trash or litter See Ponds Checklist See Ponds Checklist Causes of erosion are identified and steps taken to slowdown/spread out Erosion of ground Notrcable ells are seen in landscaped the water Eroded areas are filled M,S surface areas contoured and seeded Limbs or parts of trees or shrwbs that are Tnm trees/shrubs to restore shape Trees and spUt or broken which affect more than 25% Replace trees/shrubs with severe shrubs Damage of the total fodage of the tree or shrub damage Replant tree inspecting for injury to Trees or shrubs that have been blown stem or roots Replace if Beverly M down or knocked over damagetl Trees or shrubs which are not adequately Place stakes and rubber-coated ties supported or are leaning over causing around young trees/shrubs for exposure of the roots support If you are unsure whether a problem exists, please contact the Junsdidion and ask for technical assistance Comments ' A =Annual (March or Apnl prefered) M =Monthly (see schedule) S =After motor storms 1 ' ATTACHMENT "A' (CONTINUED) Maintenance Checklist for Access Roads/Easements Drainage System Frequency Feature J Problem Conditions to check for Conditions that Shall Exist If pontls or other drainage system Determine whether an easement t features needing maintenance by drainage feature exists If yes obtain City motorized equipment are present either permits and construct gravel (or equal) No access an access road or access from public access road If not, report lack of One time General road exists streets ~s regwred easment to City attention Blocked Debris which could damage vehicle tires Roadway free of debris which could M roadway (glass or metal) damage tires Any obstruchons which reduce clearance above road surface to less than 14 feet Roadway overhead clear to 14 feet high Any obstructions restricting the access to Obstruction removed to allow at least a less than 15 feet width 15 foot wide access When any surface defect exceeds 6 Road surface uniformly smooth with no Settlement inches in depth and 6 square feet in evidence of settlement potholes mush potholes area In general any surface defect spots or ruts Occasionally application of Road mush spots which hinders or prevents maintenance additional gravel or pit run rock will be S surface ruts access needed Remove woody growth at early stage to Vegetation prevent vehicular blockage Cut back Shoulders m road Woody growth that could block vehicular weeds if they begin to encroach on road M and ditches surface access Excessive weed cover surface Erasion within 1 foot of the roadway Erosion more than 8 inches wide and 6 inches Shoulder free of erosion and matching M,S damage deep the surrounding road !f you are unsure whether a problem exists please wntad the Jurisdiction and ask for technwal assistance ' Comments A =Annual (March or April prefered) M =Monthly (see schedule) ' S =After ma/or storms VORTECHST"' STORMWATER TREATMENT SYSTEM MAINTENANCE ^ The Vortechs System should be inspected at regular intervals and maintained when necessary to ensure optimum performance The rate at which the System collects pollutants will depend ' more heavily on site activities than the size of the unit, e g , unstable sods or heavy winter sanding will cause the grit chamber to fill more gwckly but regular sweeping will slow accumulation 1 Inspection Inspection is the key to effective maintenance and is easily performed Vortechnics recommends ongoing quarterly inspections of the accumulated sediment Pollutant deposition and transport may vary from year to year and quarterly inspections will help insure that Systems are cleaned out at the appropriate time Inspections should be performed more often m the ' winter months m climates where sanding operations may lead to rapid accumulations, or in egwpment washdown areas It is very useful to keep a record of each inspection A simple form for doing so is provided The Vortechs System should be cleaned when inspection reveals that the sediment depth has accumulated to within six inches of the dry-weather water surface elevation This determination can be made by taking 2 measurements with a stadia rod or similar measuring device, one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface The System should be cleaned out if the difference between the twc measurements is six inches or less Note to avoid underestimating the volume of sediment m the chamber, the measuring device must be lowered to the top of the sediment pile carefully Finer, silty particles at the top of the pile typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile Gleantng Maintaining the Vortechs System is easiest when there is no flow entering the System For this reason, it is a good idea to schedule the cleanout during dry weather Cleanout of the Vortechs System with a vacuum truck is generally the most effectroe and convenient method of excavating pollutants from the System If such a truck is not available, a "clamshell" grab may be used, but it is difficult to remove all accumulated pollutants with such devices In Vortechs installations where the risk of large petroleum spills is small ligwd contaminants may not accumulate as quickly as sediment However, an oil or gasoline spill should be cleaned out immediately Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured To remove these pollutants, it may be preferable to use adsorbent pads since they are usually cheaper to dispose of than the oil water emulsion that may be created by vacuuming the oily layer Trash can be netted out if you wish to separate rt from the other pollutants Accumulated sediment is typically evacuated through the manhole over the grit chamber Simply remove the cover and insert the vacuum hose into the grit chamber As water is evacuated, the water level outside of the grit chamber will drop to the same level as the crest of ' the lower aperture of the grit chamber It will not drop below this level due to the fact that the bottom and sides of the grit chamber are sealed to the tank floor and walls This "Water Lock" VORTECHST"' STORMWATER TREATMENT SYSTEM feature prevents water from migrating into the gnt chamber, exposing the bottom of the baffle wall Floating pollutants will decant into the gnt chamber as the water level there is drawn down This allows most floating matenal to be withdrawn from the same access point above the gnt chamber If maintenance ~s not pertormed as recommended, sediment may accumulate outside the gnt chamber If this is the case, it may be necessary to pump out all chambers It is a good idea to check for accumulation m all chambers dunng each maintenance event to prevent sediment build up there Manhole covers should be securely seated following cleaning acbvities, to ensure that surface runoff does not leak into the umt from above \IORTECHSTM STORMWATER TREATMENT SYSTEM INSPECTION ~ IVIAINTENAIVCE LOG 2 For optimum performance the System should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness In fhe event of a spill the System should be cleaned immediately 1 1 The water depth to sediment is determined by taking two measurements moth a stadia rod one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface When the difference beiween the two measurements is six inches or less the System should be cleaned out ATTACHMENT "B" ' POLLUTION SOURCE CONTROL PROGRAM Pollution source controls are actions taken be a person or business to reduce the amount ' of pollution reaching surface water and groundwater A conscious control program ~s of srgmficant unportance to the YELM COMMUNITY SCHOOLS, as runoff call be drrected to a constructed wetland and infiltration disposal facility that will ultunately introduce the collected runoff m to the shallow groundwater system Many pollutants generated on commercial sites can not be removed from the runoff by conventional treatment and may eventually enter the shallow groundwater system Hence, it rs of great ' unportance to hrmt the development of these pollutants in the generated stormwater runoff The subject controls are also known as "Best Management Practices" (BMP's), include • Minimizing vegetahon/groundcover disturbance • Stabrhzmg existing exposed soil surfaces through fertilizing and seeding, and mulching with chopped hay during the wet season (15 October through I S ' Mazch) • Maintaining roof, sidewalk and paved driveway areas free of debris accumulation, refratmng from using soaps and detergents in washing these exterior surfaces, and carefully controlling activities m these areas so as to preclude hazardous materials spills (i a chemical storage, vehicle maintenance, etc ) • Substitute non-toxic products for toxic materials, recycle used oil and antifreeze immedrately • Refrain from storing hazardous or toxic chemicals or other substances Where it is rmperative to store such materials, enclose them in a lockable cabinet • Limit the use of fertilizers and pesticides to the precise amount recommended by professionals working the area Pollution source controls aze needed because of the contamination found m runoff from commercial areas and the effect of this contannation on aquatic life and human health Research on urban runoff m the Puget Sound area and elsewhere has found oil and grease, nutrients, organic substances, toxic metals, bacteria, vu-uses, and sedunents at unacceptable levels Effects of contaminated runoff include closure of shellfish harvesting areas and swimming azeas, mortality of young fish and other aquatic ' organisms, tumors on fish and rmpalnnent offish reproduction 1 1 C ~]'~~~~ ~ Tl~g9rst®u ~~~Il®n S~®rmwater Facilities Summary 1 1 1 1 1 THURSTON REGION FACILITY SiJMMARY FORM PROPONENT'S FACILITY IDENTIFIER Yelm Junior High School NAME OF ROAD TO ACCESS FACILITY Carter Street SE HEARINGS EXAMINER CASE NUMBER DEVELOPMENT REVIEW PROJECT NO BUILDING SITE APPLICATION NO PARCEL NUMBER(S) To be completed by Utility Staff Utrhty Facility Number Protect Number Parcel Number Status Basm & Subbasm Responsible Junsdretion PART 1 -Protect Name & Proponent Protect Name Yelm tumor High School Protect Owner Yelm Community Schools Protect Contact Address Telephone Protect Proponent Address 217225140100 Erlmg Birkland P O Box 476, Yetm, WA 98597 (360) 458-6128 Yelm Community Schools P O Box 476, Yelm, WA 98597 1 1 i ;~ 1 1 1 Telephone (360) 458-6128 Protect Engineer Robert E Tauscher, P E Firm J W Momssette 8c Associates Inc , P S Telephone (360) 352-9456 Fax (360) 352-9990 PART 2 - Protect Locahon Secrion 25 Township 17N Range 1 E PART 3 -Type of Permit Apphcatwn Type of Pemmt Administratwe Srte Plan Review Other Permits Grading Other Other Agencies that have had or will review this Drainage & Erosion Control Plan None PART 4 -Proposed Prolect Descnphon What stream basin is this protect within Thompson Creek Zoning Inst~tuhonal Distract Onsrte Junior High School Number of Lots 1 Avg Lot Size N/A Building PermiUCommercial Plat 1 1 1 New Buiidmg Footprint (Beres) 2 26 Concrete Srdewalk Paving (Acres) 1 57 Gravel Surface (Acres) 0 Lattice Block Paving (Acres) 0 Public Roads (frontage improvements) (Acres) 0 00 Private Parking Lots (mcl gravel shoulder) (Acres) 3 96 Disturbed Impervious Surface Tota1(Acres) 6 22 PART 5 -Pre-Developed Project Srte Charactenstrcs Stream Through Site N Steep Slopes (> 10%) N Erosion Hazard N 100-Year Flood Plain N Wetlands N Seeps/Springs N High Groundwater Table N Agwfer Sensitive Area N Other PART 6 -Zone 1 - Fac-hty Descnpt~on - Junior I-d~gh School Area Tributary to Facility Including Offsite (Acres) 11 68 Acres Total Onsrte Area Tributary to Facility (Acres) 11 68 Acres Design Impervious Area Tributary to Facility (Acres) 6 22 Acres Design Landscaped Area Tributary to Facility (Acres) 5 46 Acres Design Total Tributary Area to Facility (Acres) 9 39 Acres Basin Area (Acres) 21 07 Acres Enter a check mark and number, i e ,one (1), for the type of facility 1 Wet Pond Detention 0 Wet pond water surface area, acres 0 Dry Pond Detention 1 ' Underground Detention 0 Infiltration Trench 0 Dry Well Infiltration 0 ' Other Infiltration Gallery 0 Outlet Type (Enter a check mark and number, r e ,one (1), for each type present) 1 Filter 0 Oil/Water Sepazator 0 ' Single Orifice 0 Multrple Orifice 0 Werr 0 Spillway 0 Pump(s) 0 ' Other PART 7- Zone 1 -Release to Groundwater Design Percolation Rate to Groundwater 10 m/hr PART 8- Zone 1 -Release To Surface Water All stormwater from this srte is infiltrated on site with no release to any surface waters PART 6 -Zone 2 - Facdrty Description - Mdl Pond Elementary School Total Area Tributary to Facility Including Offsrte (Acres) 9 63 Acres Total Onsite Area Tributary to Facility (Acres) 9 63 Acres Desrgn hnpervious Area Tributary to Facility (Acres) 4 62 Acres Design Landscaped Area Tributary to Facilrty (Acres) 5 O1 Acres ' Design Total Tributary Area to Facility (Acres) 9 63 Acres ' Enter a check mark and number, r e ,one (1), for the type of facrhty Wet Pond Detention 0 1 Wet pond water surface area, acres 0 Dry Pond Detention 0 ' Underground Detention 0 Infiltration Trench 0 Dry Well hililtration 0 ' Other Infiltration Gallery 1 Outlet Type (Enter a check mark and number, r e ,one (1), for each type present) 1 1 Filter 0 OiUWater Sepazator 0 Single Onfice 0 Multiple Onfice 0 Weir 0 Sprllway 0 Pump(s) 0 Other PART 7 -Zone 2 -Release to Groundwater Design Percolation Rate to Groundwater 10 m/hr PART 8 -Zone 2 -Release To Surface Water All stormwater from this site is infiltrated on site v~nth no release to any surface waters d~~ uis~~ ~ XIQI~~dd~' O \03 157v1h\Contract Drawu~as\Constructabdity Review\03 157-STORM\03 157-Site Plan ReviPUi rimier I I / I /9nn4 4 SF I n PM_ 1 9 1 99fi4 ~~ ~;~ ,q4 B¢~ R=8 a .m n ~8$ o ~~~ e ~s w€ 4R§ e ~b n~k m ~O x I r pq: Q O Oyy yy~ '1~ O Z o ~ n ~ 0 a ~ ~S a ` ~ 7 ,~ } n W p < ti -, _ o. ~ 3 N ~ m ~ n F rf a w (D °' QO N o ~ n a N _~ s Q n d wn m o w~ r+ ro `n . w T~ v wn P ~' O -Q N 7 7_ O v' ~ / ~ O i ~~~ VIII R n L ~ n~ 4 "+ k e r E ~ + ` i i ~ I I E I 1 ~ AE'I' per-0=~,>,,,s~s`¢©n ~ i " a R ~ ~ 4' ° o A a 4 x ~ ~ ~g ~ ~ ~ z` ~ Y ~ P s~ e~ ~ ~ x K F R~~ Z A ^ ~ A ~ F` ~ 1 ~"`~ (A ,~ rn _ n ' "~ ~ ~ N f, ~. ~;~ -/_ -1~ 1 Z 1 m ~ti a Y u"ck Y' FI miaG o~~c ~ F O O qo Lt9 ~x umw 31, ee1tl11B.N Y SITE PLAN ~a ~.. ~'` YELMJUNIORHIGHSCHOOL Arehlteet~re An~~7~~~ seMooloe~ton ~ Yelm Commurniy Schools No 2 Thurston County Yelm WA ~a :~~s~~~; ~maExr~~ ~ m 1 t 1 L~~~~~~~~ ~a H'~l'al~Tl\A~1V~9~7 L~~ylO'~~~~ 1 YELM COMMUNITY SCHOOLS YELM JUNIOR HIGH SCHOOL ENGINEER'S ESTIMATE 7 0/22/2004 1 1 1 1 BASE BID Brd Item Approx Btd Item Umt Eng's Es[tmate Number Quanhry Umt Pnce Total Pnce I 1 Mobdvahon L S $180 000 00 $180,000 00 2 I Cleartn & Gmbbm L S $35,000 00 $35 000 00 3 1 Tmm~un & Cleanu L S $25 000 00 $25 000 00 q 100 Saw Cuttm L F $2 40 $240 00 5 6,210 Batlast TON $13 00 $80 730 00 6 1 895 Crushed Surfacm To Coarse TON $15 00 $28 425 00 7 4 435 As halt Concrete Pavement TON $55 00 $243 925 0 g 1,109 As halt Ratsed Ede L F $120 00 $133 080 0 9 1100 Sdt Fence L F $7 00 $7 700 0 10 4 835 Cement Concrete Bamer Curb L F $13 00 $62 855 00 I 1 4 890 Cement Concrete Sidewalk S Y $22 00 $107 580 0 l2 550 Cement Concrete Cmb and Gutter L F $20 00 $11,000 0 13 1 35000 Gallon STEP Tank Com lete Each $110 000 00 $110 000 00 14 837 6-Inch Gravt Sewer Pte L F $30 00 $25 110 00 15 266 2-Inch Forcemam STEP Sewer Pt a Com fete L F $15 00 $3 990 00 16 l l Sami Sewer Cieanout Each $200 00 $2 200 0 17 17 279 Structural Excavation Class B Incl Haul C Y $13 00 $224 627 00 18 1 582 ADS-N12 PE Corru azed Storm R e 12 m Dtam L F $35 00 $55 370 00 19 630 ADS-Nl2 PE Corru ated Stonn Pte 18 m Dtam L F $40 00 $25 200 00 20 37 ADS N12 PE Corru ated Storm Pt e 24 m Dtam L F $40 00 $1 480 0 21 1 270 46' Perf Alum Steel 14 GA Pt e -Com lete L F $65 $82 550 0 22 2 064 4" PV C Roof Dram Pt L F $12 00 $24 768 0 23 1 Vortechntc Treatment Device Model 16000 Each $88 000 00 $88 000 0 24 12 Catch Basin f e 1 EA $2 000 00 $24 000 00 25 4 Catch Basin T e 2 EA $1 100 00 $4 400 0 26 11 Concrete Inlet EA $600 00 $6 600 00 27 5 Area Drams EA $300 00 $1 500 0 28 1 007 1 1/2 Inch Infiltratton Galle Washed Dram Rock TON $18 00 $18 126 0 29 1 797 Geotexhle S Y $22 50 $40 432 50 30 215 R e Beddm C Y $12 00 $2 580 00 3 ] 2 279 10 Wazermam L F $60 00 $136 740 00 32 6 10" Gate Valve Each $750 00 $4 500 0 33 73 8 Watennam L F $45 00 $3,285 00 34 2 8" Gate Valve Each $750 00 $I 500 00 35 449 6 Watennam L F $40 00 $17 960 0 36 5 Ftre Hydrant Assembly Each $2 500 00 $12 500 0 37 2 Post Indicating V alve Each $2 500 00 $5 000 00 3g 2 Fue Department Connection Each $1 500 00 $3 000 00 Base Btd Subtotal $1 840 953 50 Sales Tax Q 8 4 % $154 640 09 Total Base Btd (Incl Sale Tax) $I 995 593 5 ' 1 of 7 1 ~~~~~ x i 1 i i 1 1 Adjacent Weds 1 Thurston County Map Output Page __ ' I __.. ~~~ Thurston ~~~~a~~.~~~~~~~~~~~~~a~~ :~~ http //geomapl geodata org/servletlcom esn esnmap Esnmap~Servt .•_ ~~r Dtsclatmet Thwston County makes every cftor[ to ensure that thts map rs a ' rtrue and accurate representation of the work of County government Flowever ;the CounTy and all related personnel make no warranty expressed or implied regar dmg the accuracy completeness or convenience of any mfonnahon disclosed on this map Nor does [he County accept habdrt} for anv damage of ' ~ m~ury caused by the use of flits map To the fullest entent permtssibte pursnanl to applicable law Thurston County dtsolatms all warranties express or tmphed mcludmg, but not hmtted [o impbed warzannes of merchant abiht~ data fitness for a particular purpose, and non-mfrineements of propnetary nghts r Under no circumstances mcludmg but not hmrted to, negligence shall a Thurston County be liable for anv direct mduect, incidental, special or ;consequential damages that result from [he use of or the inability to use ' ~ Thurston County materials 6 'fhur3ton n ~~ 2001 Thurston County GeoData Center ' s i cuUata `Bld p4 Rm 205 927 Lakend e Dr SW Crnrcn';.; ~' g Sr Olympra, WA 98502-6052 ~of 1 012 9 /20 0 4 l t 43 u~ld a$r~ ,~ XIQ~~dd~