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TECHNICALINFORMATIONREPORTProposedHarperEngineeringParkingLotAddition800S.W.7thStreetRenton,Washington98057Preparedfor:HarperEngineeringCo.700S.W.7thStreetRenton,Washington98057August22,2014RevisedFebruary9,2015RevisedApril8,2015RevisedMay27,2015OurJobNo.16585CIVILENGINEERING,LANDPLANNING,SURVEYING1821572NDAVENUESOUTHKENT,WA98032(425)251-6222(425)251-8782FAXBRANCHOFFICES+ThMWATER,WA•LONGBEACH,CA.ROSEVILLE,CA.SANDIEGO,CAwww.barghausen.com‘V0CC TABLEOFCONTENTS1.0PROJECTOVERVIEWFigure1—TechnicalInformationReport(TIR)WorksheetFigure2—SiteLocationFigure3—DrainageBasin,Subbasins,andSiteCharacteristicsFigure4-Soils2.0CONDITIONSANDREQUIREMENTSSUMMARY2.1AnalysisoftheCoreRequirements2.2AnalysisoftheSpecialRequirements3.0OFF-SITEANALYSIS4.0FLOWCONTROLANDWATERQUALITYFACILITYANALYSISANDDESIGN5.0CONVEYANCESYSTEMANALYSISANDDESIGN6.0SPECIALREPORTSANDSTUDIES7.0OTHERPERMITS8.0CONSTRUCTIONSTORMWATERPOLLUTIONPREVENTIONPLANANALYSISANDDESIGN9.0BONDQUANTITIES,FACILITIESSUMMARIES,ANDDECLARATIONOFCOVENANT10.0OPERATIONSANDMAINTENANCEMANUAL16585.D03dcc 1.0PROJECTOVERVIEW 1.0PROJECTOVERVIEWTheproposedprojectsiteislocatedona1.026-acreparceljustnorthoftheexistingHarperEngineeringdevelopment.ThisparcelisalsoownedbyHarperEngineeringandwillhave24,000squarefeetofpermeableasphaltinstalledintheupperreachesofthisdevelopmentarea.ThesiteislocatedwithintheSouthwestquarterofSection18,Township23North,RangeSEast,WillametteMeridian,CityofRenton,KingCounty,Washington.Moreparticularlythesiteislocatedinalandlockedareaat800S.W.7thStreetwithintheCityofRenton.Railroadtracksformtheprojectsite’snorthern,southern,andeasternboundarieswithothercommercialpropertyborderingonthewest.Theexistingconditionofthesiteconsistsofvacantrawlandwithsecondgrowthforestoverportionsofitandthickbrushovertheremainingportionofthesite.Thereisanexistingwetlandlocatedinthenorthwestcorneroftheoverallarea.Tworailroadgradesformtheproject’snorth,east,andsouthboundariesasmentionedpreviouslyandtheseroadgradesarehigherinelevationthanthesiteis.TheproposalforthisdevelopmentistoprovideanasphaltroadwaycrossingoftheBurlingtonNorthernRailroadtrackalongthesouthernpropertylineofthesitewithaccesscomingfromtheexistingHarperEngineeringdevelopmentontheothersideoftherailroadtracks.Thenpermeableasphaltwillbeconstructedtotaling24,000squarefeetwitha1percentslopefromsouthtonorthandalong-terminfiltrationrateof0.3inchesperhourasdeterminedbythegeotechnicalengineerforthisproject.PleaserefertoSection6.0oftheTechnicalInformationReportforthesoilsreportpreparedforthisproject.Theproposednewparkinglotwillhaveappropriatedriveaisleswithintermittentlandscapingislands,alltocreateasiteconformingtotherequirementsoftheCityofAuburn.Inaddition,thesiteislocatedonthewesternfringeofanaquiferrechargearea;however,theon-sitesoilsexhibitaninfiltrationrateslowenoughtoprovidetreatmentforstormwaterrunoffinfiltratingthroughtheminorderthatalinerwillnotberequiredforthesesoils.Thisprojectwillincludetheclearingofvegetatedlandwithretentionofasmanylarge-diametertreesasphysicallypossiblewithadevelopmentofthisnature.Therewillbenoimpactstothedownstreamdrainagecoursefromthissitewhichouffalls,shouldtheinfiltrationfacilitieseverovertop,totheBlackRiverareawithinseveralhundredfeetwestoftheprojectsite.Therearetwosoiltypesonthisprojectsite,WoodinvillesiltloamandBeausitegravellysandyloamwith6to15percentslopesalsoontheprojectsite.PleaserefertotheSoilsMaponthefollowingpagesofthisreportforhowtheon-sitesoilswereconfiguredontheprojectsite.TheKingCountyRunoffTimeSeries(KCRTS)hydrologymodelwasutilizedinsizingthepermeableasphaltpavementsectionforthisprojectsite.A24-inchsectionwaselectedwith3inchesofpermeableasphaltover3inchesofgravelbasewithaminimumoffinesoveranother18inchesofgravelmaterial.Sincetheparkinglotslopes,theeffectivedepthattheupperendof•theparkinglotisapproximately6inches.Thelivestoragedepthinthe24-inchsectionisonly0.17feetperthecalculations.So,thereisexcessfreeboardinthesection.I6585.0034oc Figure1—TechnicalInformationReport(TIR)Worksheet KINGCOUNTY,WASHINGTON,SURFACEWATERDESIGNMANUALTECHNICALINFORMATIONREPORT(TIR)WORKSHEETPart5PLANANDREPORTINFORMATIONTechnicalInformationReport—SiteImprovementPlan(Engr.Plans)TypeofDrainageReviewITargeted/Type(circleone):IModified/(circle):LargeSiteSmallSiteDate(includerevisionDate(includerevisiondates):dates):DateofFinal:—DateofFinal:Part6ADJUSTMENTAPPROVALSType(circleone):StandardIComplexIPreapplication/ExperimentalIBlanketDateofApproval:Description:(includeconditionsinTIRSection2)1/1/09PartIPROJECTOWNERANDPROJECTENGINEERProjectOwnerHarperEngineeringPhon e _____ ___ ___ __ _ __ _ __ ___ _Address700S.W.7thStreet,Renton.WAProjectEngineerCostaPhilippidesCompanyBarghausenConsultingEngineers,Inc.Phonei25)25J222____ _Part2PROJECTLOCATIONANDDESCRIPTIONProjectNameHarperEn.ParkingLotExp.DDESPermit#__ _ _ ____ _ _ ____LocationTownship23NorthRange5EastSection18SiteAddress800SW.7thStreet.Renton.WAPart3TYPEOFPERMITAPPLICATIONCLanduseServicesSubdivision/ShortSubd.IUPDBuilding_ServicesM/FIlCommercia(ISFRClearingandGradingCRight-of-WayUseCOtherPart4OTHERREVIEWSANDPERMITSCDFWHPACShorelineCCOE404ManagementCDOEDamSafetyCStructuralRockeryWaulu_____CFEMAFloodplainCESASection7CCOEWetlandsCOther__ ___ __ _2009SurfaceWaterDesignManual16585.004.doc KINGCOUNTY,WASHINGTON,SURFACEWATERDESIGNMANUALTECHNICALINFORMATIONREPORT(TIR)WORKSHEETPart7MONITORINGREQUIREMENTSMonitoringRequired:Yes/Describe:StartDate:CompletionDate:PartsSITECOMMUNITYANDDRAINAGEBASINCommunityPlan:RentonSpecialDistrictOverlays:DrainageBasin:StormwaterRequirements:Part9ONSITEANDADJACENTSENSITIVEAREASRiver/StreamflSteepSlopeLakeflErosionHazardWetlandsCLandslideHazardDClosedDepressionCCoalMineHazardFloodplainTothewestonadjacentpropertyCSeismicHazardCOtherCHabitatProtectionCPart10SOILSSoilTypeSlopesErosionPotentialWoodinvillesiltloamBeausitegravellysandyloam6to15percentCHighGroundwaterTable(within5feet)CSoleSourceAquiferCOtherflSeeps/SpringsCAdditionalSheetsAttached2009SurfaceWaterDesignManual1/1/09216585.004.doc KINGCOUNTY,WASHINGTON,SURFACEWATERDESIGNMANUALTECHNICALINFORMATIONREPORT(TIR)WORKSHEETPart11DRAINAGEDESIGNLIMITATIONSREFERENCELIMITATION/SITECONSTRAINTQCare2—OffsiteAnalysisflSensitive/CriticalAreasCSEPAJOtherC0AdditionalSheetsAttachedPart12TIRSUMMARYSHEET(provideoneTIRSummarySheetperThresholdDischargeArea)ThresholdDischargeArea:(nameordescription)CoreRequirements(allBapply)DischargeatNaturalLocationNumberofNaturalDischargeLocations:IOffsiteAnalysisLevel:1/2/3dated:N/AFlowControlLevel:1/2/3orExemptionNumber(md.facilitysummarysheet)SmallSiteBMPsPorouspavementConveyanceSystemSpillcontainmentlocatedat:N/AErosionandSedimentControlESCSiteSupervisor:ContactPhone:AfterHoursPhone:MaintenanceandOperationResponsibility:IPrivatIPublicIfPrivate,MaintenanceLogRequired:fri1INoFinancialGuaranteesandProvided:YesINoLiabilityWaterQualityType:Basic/Sens.Lake/EnhancedBasicm/Bog(includefacilitysummarysheet)orExemptionNo.LandscapeManagementPlan:Yes/NoSpecialRequirements(asapplicable)AreaSpecificDrainageType:CDA/SDO/MDP/BP/LMP/SharedFac./NoneRequirementsName:Floodplain/FloodwayDelineationType:Major/Minor/Exemption/Nonel100-yearBaseBloodElevation(orrange):Datum:FloodProtectionFacilitiesDescribe:SourceControlDescribelanduse:(comm/industriallanduse)Describeanystructuralcontrols:2009SurfaceWaterDesignManual1/1/09316585.004.doc KINGCOUNTY,WASHINGTON,SURFACEWATERDESIGNMANUALTECHNICALINFORMATIONREPORT(TIR)WORKSHEETOilControlHigh-useSite:YesITreatmentBMP:MaintenanceAgreement:Yes/withwhom?OtherDrainageStructuresDescribe:Part13EROSIONANDSEDIMENTCONTROLREQUIREMENTSMINIMUMESCREQUIREMENTSMINIMUMESCREQUIREMENTSDURINGCONSTRUCTIONAFTERCONSTRUCTIONClearingLimitsEStabilizeExposedSurfacesElCoverMeasuresRemoveandRestoreTemporaryESCFacilitiesPerimeterProtectionCleanandRemoveAllSiltandDebrisEnsureElTrafficAreaStabilizationOperationofPermanentFacilitiesElSedimentRetentionFlagLimitsofSAOandopenspacepreservationareasElSurfaceWaterControlOtherElDewateringControlElDustControlElFlowControl—Part14STORMWATERFACILITYDESCRIPTIONS(Note:IncludeFacilitySummaryandSketch)FlowControlType/Description—WaterQualityType/DescriptionElDetentionflBiofiltrationElInfiltrationElWetpoolElRegionalFacilityflMediaFiltrationElSharedFacilityElOilControlFlowControlPAhflSpillControlBMPsorousspatEFlowControlBMPsElOtherPorousAsphaltflOther2009SurfaceWaterDesignManual1/1/094I6585.004doc KINGCOUNTY,WASHINGTON,SURFACEWATERDESIGNMANUALTECHNICALINFORMATIONREPORT(TIR)WORKSHEETPart15EASEMENTS/TRACTSPart16STRUCTURALANALYSISDrainageEasement—DCastinPlaceVaultCCovenantflRetainingWallCNativeGrowthProtectionCovenantRockery>4HighCTractflStructuralonSteepSlopeCOtherflOtherPart17SIGNATUREOFPROFESSIONALENGINEERI,oracivilengineerundermysupervision,havevisitedthesite.ActualsiteconditionsasobservedwereincorporatedintothisworksheetandtheattachedTechnicalInformationReport.Tothebestofmyknowledgetheiformationprovidedhreisaccurate.k9EIA/&Q4AKAJ/(-z4’14,‘7/Signed/Date‘U2009SurfaceWaterDesignManual1/1/09516585.004.doc Figure2—SiteLocation REFERENCE:RandMcNally(2014)‘pcsNtCItScale:For:JobNumberHorizontal:PITS.Vedical.N/AHARPERENGINEERING16585&Au•1821572NDAVENUESDUTHRENTON,WASHINGTON•KENT,WA98032-2(425)251-6222Title:\$J:VICINITYMAP(425)251-8782CIVELENGINEERING,LANDPLANNING,‘CSURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14-Th..L1)S16n2n1ItU,I’I’-IItSI,H..--SwSunsctBlvd—:.•-—‘_lthp/Sw7thSt‘I,0CSva7thSt‘OCLw7thStU,ItSC-C-o0ItItU,1ccC,CI:IL;OtSW—I5gJ1OtStSW63d9\‘JyStSIpIt•=;SwI6tISt’—Sw16thSt=-.=U,HISwl6thSt=SwLiCVP:\l6000sIl6585Wxhthiflgmphicsl6585vmap.cdr Figure3—DrainageBasin,Subbasins,andSiteCharacteristics no’Doll,ROlSGMLPlOSP€tDIG.o‘6585flyPtonning/Butlding/PubticaCITYOFHABPERENGINEERINGPARKINGLOTRENTON700SWTh-ISThEETRENTON,WASHINGTONWorksDept.MNGPLAN21>r210C02100303a0CD0aS—01’=20’0amram210ICmCCD0aCC!1i”Ij_________F’1!U?•____________________I‘___________pi_____-———IIiCi/itcita*<—-ttwI____Ifl4A-±,-—%_\-4II/—=*=n==z2_N=aA1—-II____jrjJI*]frJIk.—L81B035E,:1/____-)ç*I\\F.éV.;/4frVciGASPIPLiI/‘1101-—16cij:;j/I;>4ft,\f///a.ol’uA•‘:///z—CCCci%4tI13-umU,4Zzimamamp3zNi>calJDz00rnrIn—ia-f0zCZOCzC-a>zC-arzIIIIIIII•••IIIItIIIii-.III/21I.>1•00210CDCDa0-u21011rm Figure4-Soils REFERENCE:USDA,NaturalResourcesConservationServiceLEGEND:Wo=WoodinvillesiltloamSeC=Seausitegravellysandyloam,6-15%slopesscale:For:JobNumberHorizontal:MTS.Vertical:WAHARPERENGINEERING16585&H4u1821572NDAVENUESOUTHRENTON,WASHINGTON9”4In,%LKENT,WA98032ZZ(425)251-6222Title:(425)251-87825fjCiViLENGINEERING,LANDPLANNING.<>SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:ii6000sii65a5lexhibitigmphicsii65a5soiLcdr 2.0CONDITIONSANDREQUIREMENTSSUMMARY 2.0CONDITIONSANDREQUIREMENTSSUMMARY2.1AnalysisoftheEightCoreRequirementsCoreRequirementNo.1:DischargeattheNaturalLocation.Response:Allsurfacewaterrunofffromthisnewdevelopmentwillbeinfiltratedintothesoilbelowthepermeableasphaltwiththeremainderofthesitefunctioningasitdoesunderexistingconditions.Therefore,thisrequirementismetCoreRequirementNo.2:Off-SiteAnalysis.Response:SinceinfiltrationofstormwaterrunoffistheproposedmeansofFlowControlBMPforthisprojectsitewithalloftherunoffinfiltratingreadilyintoground,noOff-SiteAnalysiswaspreparedforthissite.However,shouldrunoffeverovertoptheporouspavement,itwouldsheetflowtothewestintotheBlackRiverdrainagebasinattheBlackRiverPark.CoreRequirementNo.3:FlowControLResponse:FlowcontrolisbeingprovidedwiththisprojectintheformofaFlowControlBMPfortheentiredevelopedareaonthesitewhichmeetstherequirementsoftheCityofRentonforprojectsofthisnature.Therefore,thisCoreRequirementismet.CoreRequirementNo.4:ConveyanceSystem.Response:Thereisnoconveyancesystemproposedforthisdevelopment;therefore,thisCoreRequirementdoesnotapply.CoreRequirementNo.5:ErosionandSedimentControLResponse:Allerosionandsedimentcontrolrequirementsofthe2009KingCountySurfaceWaterDesignManualwillbefollowedwiththissiteasmodifiedbytheCityofRenton’samendments.Covermeasureswillbeprovided,clearinglimitswillbespecified,arockconstructionentrancewillbeinstalled,anddownstreamperimeterprotectionwillalsobeutilizedintheformofsiltfencestomaintainthatallrunoffleavingtheprojectsiteeitherinfiltrates,orshoulditconcentratebedispersedthroughthenativevegetationwithnosedimententrainedinthewater.CoreRequirementNo.6:MaintenanceandOperations.Response:AMaintenanceandOperationsPlanwillbepreparedwiththefinalpreparationoftheTechnicalInformationReportforthisproject.CoreRequirementNo.7:FinancialGuaranteesandLiability.Response:AllfinancialguaranteesandliabilitiesrequirementsoftheCityofRentonwillbefollowedforthisprojectaspertherequirementoftheCity.CoreRequirementNo.8:WaterQuality.Response:Theon-sitesoilsexhibitwaterqualitytreatmentcapabilitysincetheinfiltrationrateissosmall.Therefore,nofurtherwaterqualityrequirementisrequiredforthisproject.Thesiteislocatedinanaquiferrechargeareaandtheon-sitesoilswillprovidetherequiredtreatment.16585.003.dcc 2.2AnalysisoftheSixSpecialRequirementsSpecialRequirementNo.1:OtherAdoptedArea-SpecificRequirements.Response:Therearenoknownotheradoptedarea-specificrequirementsforthisareabytheCityofRentontothebestofourknowledge.SpecialRequirementNo.2:FloodHazardAreaDelineation.Response:TheBlackRiverislocatedwesterlyoftheprojectsiteandhasaFloodHazardAreaassociatedwithit.However,noneofthe100-yearfloodplainiswithintheprojectlimitsonthissite.SpecialRequirementNo.3:FloodProtectionFacilities.Response:ThisSpecialRequirementisnotapplicabletothisprojectsite.SpecialRequirementNo,4:SourceControl.Response:Theprojectsiteparkinglotwillhavetobesweptonaregularbasisandvacuumedaswellinordertomaintainthepermeabilityoftheasphaltonthisprojectsite.Thereshouldbenootherformsofpollutionotherthanoilandsedimentonthisareaoftheoveralldevelopment.SpecialRequirementNo.5:011Control.Response:Thisprojectdoesnotmeetthecharacteristicsofahigh-usesite;therefore,thisSpecialRequirementdoesnotapply.SpecialRequirementNo.6:AquiferProtectionArea.Response:ThisprojectisontheouterlimitfringeofanAquiferProtectionAreaandtheon-sitesoilsprovideadequatewaterqualitythroughinfiltrationthroughtheunderlyingsoilbelowthepermeableasphalt.Therefore,nofurtherliningoraquiferprotectionrequirementsapplytothisprojectsite.16585.003.doc 3.0OFF-SITEANALYSIS 3.0OFF-SITEANALYSISNooff-siteanalysiswaspreparedforthisprojectsiteasallrunoffgeneratedfromtheproposedparkinglotareawillbereadilyinfiltrated,includingrunofffromanyupstreambasindrainingontothepermeableasphalt.Asmallslopedareabetweentherailroadtracksandthepermeableasphaltwilldraindowntothepermeableasphalt;however,inthesizingofthepavementsection,thereisadequatesafetymeasuretoinfiltrateallstormwaterrunoffthatlandsonthepermeableasphalt.Therefore,nofurtherupstreamordownstreamanalysiswasperformedforthisproject.16585.003.doc FEMAMAP ZONEXAreasd(h,mr,dCondpb}n.REFERENCE:FederalEmergencyManagementAgency(PortionofMap53033CD976F,May1995)Scale:For:JobNumberHorizontal:N.TS.Vertical:N/AHARPERENGINEERING165851821572NDAVENUESOUTHRENTON,WASHINGTONKENT,WA98032In(425)251-6222Title:-,(425)251-8782FEMAMAP\-CIVILENGINEERING,LANDPLANNING,SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:l6OOOsI16585IexhibitIgmphics16565fema.cdr ASSESSOR’SMAP aREFERENCE:KingCountyDepartmentofAssessments(May2014)Scala:For:JobNumberHodzonM:N.ES.Vertical.N/AHARPERENGINEERING16585&4A,1821572NDAVENUESOUTHRENTON,WASHINGTON74fl%4%KENT,WA98032(425)251-6222Title:(425)251-8782\ASSESSORMAPCIVILENGINEERING,LANDPLANNING.SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:16OOOsIl6585IexhthitlgraphicsI16585amap.cdr SENSITIVEAREASFOLIOS REFERENCE:KingCountyMAP(2014):,i‘!hI..fLegend0Scale:For:JobNumberHorizontaLN.ZS.Vefljcat:HARPERENGINEERING16585e”4&•/1821572NDAVENUESOUTHRENTON,WASHINGTON.•KENLWA98032WZ(425)251-6222Title:CIVILENGINEERING,NDPNNING,MAPDATE08120/14(425)251-8782SENSITIVEAREAS&QSURVEYING,ENVIRONMENTALSERVICESCountyBoundarySAOStreamxMountainPeaks4fciHighwaysCs2PniniYStreetsfttCbnzSxmondIIi9hnyUndiLoLakesandLargeRiversParcelsStreamsSAGWetlandSAGLandslideSACCoal?MneSACSeismicSAOErosion2009ColarMdalPhotos(61n)2009ColorAerialPhotos(l2in)P:IlG000sIi65B5lexhibiLIgmphicsilGSSSsens.cdr 4.0FLOWCONTROLANDWATERQUALITYFACILITYANALYSISANDDESIGN 4.0FLOWCONTROLANDWATERQUALITYFACILITYANALYSISANDDESIGNA.ExistingSiteHydrologyUnderexistingconditionsthesiteishighlyvegetatedwithsecondgrowthforestandbrushyareas.Thereisanexistingwetlandlocatedinthenorthwestcorneroftheprojectsitewhichthesitecurrentlydrainstoifrunoffisnotinfiltratedorevaporatedpriortothat.B.DevelopedSiteHydrologyUnderdevelopedconditions24,000squarefeelofthesitewillhavepermeableasphaltappliedwithgradingoccurringinordertoprovideaparkinglotfortheproposeduseoftheexistingHarperEngineeringdevelopmentlocatedacrosstherailroadtracksandimmediatelysouthoftheprojectsite.Thispermeableasphalthasapavementsectionof24inchesincludingalsotherockandgravellayersbelowtheporousasphalt.Thiswasmorethanadequatetoinfiltrateallstormwaterrunoffgeneratedfromthepermeableasphaltandanycontributingarea.Pleaserefertothecalculationsonthefollowingpagesofthisreportforhowthatwassized.The24-inchpavementsectionwasselectedbecausetheparkinglotslopesfromsouthtonorthapproximately1.5feetinverticalrelief,whichleavesaneffectivestoragedepthinthesectionof6±inches.ThecomputeddepthoflivestoragebyKCRTScalculationswas0.17feet,sotheparkinglotshouldneverovertop.C.PerformanceStandardsTheKingCountyRunoffTimeSeriesmodelwasutilizedinsizingthepermeableasphaltpavementsectiononthisprojectsite.ThepermeableasphaltisaFlowControlBMPwhichmeetstherequirementsoftheCityofRentonforprojectsofthisnature.Waterqualityisnotrequiredastheon-sitesoilsexhibittraitsoftreatmenttypesoilsandthereisnoconveyancesystemproposedwiththisdevelopment.D.FlowControlSystemAsmentionedpreviously,theonlyflowcontrolsystemproposedforthisprojectistoutilizepermeableasphaltasaFlowControlBMP.E.WaterQualitySystemThereisnowaterqualitysystemproposedforthisproject.16585.003.doc KCRTSCALCULATIONSTOSIZETHEPOROUSASPHALT esgsHAFfCYPvicjLo1&f.Psra,c.*bePs.vttiitKCRTSCommand-O.79rIon)fermCREATEanewTimeSeriesProductionofRunoffTimeSerifr)O”5et?OflProjectLocationSea-TacComputingSeries:l6sS5infildev.tsf49IAfLRegionalScaleFactor:1.00c”VUI-DataType:Reduced/“etfcchvc_c-ehnilcythCreatingHourlyTimeSeriesFileI,LoadingTimeSeriesFile:C:\Kc_SWDM\Kc_DATA\STEI6OR.rnfImpervious0.55acresTotalArea:0.55acresPeakDischarge:0.260CFSat6:00onJan9inYearBStoringTimeSeriesFile:l6SBsinfildev.tsfTimeSeriesComputedKCRTSCommandEntertheAnalysisTOOLSModuleAnalysisToolsCommandComputePEAKSandFlowFreuenciesLoadingStage/Dischargecurve:l65Ssinfildev.tsfFlowFrequencyAnalysisTimeSeriesFile:l65Bsinfildev.tsfProjectLocation:Sea-TacFrequencies&PeakssavedtoFile:l658sinfildev.pksAnalysisToolsCommandRETURNtoPreviousMenuKCRTSCommandSizeaRetention/DetentionFACILITYEditFacilityCANCELLEDRetention/DetentionFacilityDesignSavingRetention/DetentionFacilityFile:l6sssinfil.rdfEndSizingRetention/DetentionFacilityKCRTSCommand FlowFrequencyAnalysisTimeSeriesFile:lss8binfildev.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFreouencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)Period0.13372/09/012:000.2601100.000.9900.11781/05/0216:000.200225.000.9600.163412/08/0218:000.163310.000.9000.13768/26/042:000.16345.000.8000.163310/28/0416:000.14253.000.6670.14251/18/0616:000.13762.000.5000.200210/26/060:000.13371.300.2310.26011/09/086:000.11781.100.091ComputedPeaks0.24050.000.980 FlowFrequencyAnalysisTimeSeriesFile:l6s85infilrdout.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)(if)Period0.00062/09/013:000.0000.171100.000.9900.00081/05/0217:000.0000.03225.000.9600.00042/27/038:000.0000.03310.000.9000.00078/26/043:000.0000.0345.000.8000.000310/28/0417:000.0000.0253.000.6670.00051/18/0614:000.0000.0262.000.5000.000210/26/061:000.0000.0271.300.2310.00011/09/0810:000.0000.0281.100.091ComputedPeakso.ooo0.1350.000.980 Retention/DetentionFacilityTypeofFacility:GravelInfiltrationTrenchFacilityLength:240.00ftFacilityWidth:100.00ftFacilityArea:24000.sq.ftEffectiveStorageDepth:0.50ftStage0Elevation:20.50ftStorageVolume:3600.cu.ftVerticalPermeability:200.00mm/inPermeableSurfaces:BottomRiserHead:0.50ftRiserDiameter:12.00inchesTopNotchWeir:NoneOutflowRatingCurve:NoneStageElevationStorageDischargePercolation(ft)(ft)(cu.ft)(ac-ft)(cfs)(cfs)0.0020.500.0.0000.0000.000.0320.53216.0.0GB0.0000.170.0520.55360.0.0080.0000.170.0820.58576.0.0130.0000.170.1020.60720.0.0170.0000.170.1320.63936.0.0210.0000.170.1520.651080.0.0250.0000.170.1820.681296.0.0300.0000.170.2020.701440.0.0330.0000.170.2320.731656.0.0380.0000.170.2520.751800.0.0410.0000.170.2820.782016.0.0460.0000.170.3020.802160.0.0500.0000.170.3320.832376.0.0550.0000.170.3520.852520.0.0580.0000.170.3820.882736.0.0630.0000.170.4020.902880.0.0660.0000.170.4320.933096.0.0710.0000.170.4520.953240.0.0740.0000.170.4820.983456.0.0790.0000.170.5021.003600.0.0830.0000.170.6021.103600.0.0830.3080.170.7021.203600.0.0830.8710.170.8021.303600.0.081.6000.170.9021.403600.0.0832.3900.171.0021.503600.0.0832.6700.171.1021.603600.0.0832.9300.171.2021.703600.0.0833.1600.171.3021.803600.0.0833.3800.171.4021.903600.0.0833.5900.171.5022.003600.0.0833.7800.171.6022.103600.0.0833.9700.171.7022.203600.0.0834.1400.17 20.67Ft1245.Cu-Ft0.029Ac-FtFlowFrequencyAnalysisTimeSeriesFile:l6s8sinfilrdout.tsfProjectLocation:Sea-Tac1.8022.303600.0.0834.3100.171.9022.403600.0.0834.4700.172.0022.503600.0.0834.6300.172.1022.603600.0.0834.7800.172.2022.703600.0.0834.9300.172.3022.803600.0.0835.0700.172.4022.903600.0.0835.2100.172.5023.003600.0.0835.3500.17InflowOutflowHydPeakStorageTargetCalcStageElev(Cu-Ft)(Ac-Ft)10.260.000.000.1720.671245.0.02920.14*******0.000.0220.52173.0.00430.20*******0.000.0320.53244.0.00640.16*******0.000.0320.53195.0.00450.16****“*0.000.0320.53202.0.00560.13“****0.000.0220.52166.0.00470.140.000.0220.52148.0.00380.12*******0.000.0220.52129.0.003Facilityl65ssinfildev.tsflesssinfilrdout.tsfRouteTimeSeriesthroughInflowTimeSeriesFile:OutflowTimeSeriesFile:Inflow/OutflowAnalysisPeakInflowDischarge:PeakOutflowDischarge:PeakReservoirStage:PeakReservoirElev:PeakReservoirStorage:0.260CFSat6:00onJan9inYear80.000CFSat10:00onJan9inYear80.17Ft---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)(ft)Period0.00062/09/013:000.0000.171100.000.9900.00081/05/0217:000.0000.03225.000.9600.00042/27/038:000.0000.03310.000.9000.00078/26/043:000.0000.0345.000.8000.000310/28/0417:000.0000.0253.000.6670.00051/18/0614:000.0000.0262.000.5000.000210/26/061:000.0000.0271.300.2310.00011/09/0810:000.0000.0281.100.091ComputedPeaks0.0000.1350.000.980 GRADINGANDDRAINAGEPLAN 5.0CONVEYANCESYSTEMANALYSISANDDESIGN 5.0CONVEYANCESYSTEMANALYSISANDDESIGNAsmentionedpreviously,thereisnoconveyanceproposedforthisdevelopment.Acalculationwasperformedassumingtheentireparkinglot’spermeablepavementhadfailedandusing15-minutetimestepsthe100-yearpeakflowfromtheparkinglotwillbe0.68cfs.ThisishighlyconservativesincebySBUHMethodologytheflowwouldcomputetolessthan0.5cfsforthisareaofKingCounty.Inaddition,curbbreaksareprovidedat6feetoncenteralongtheentiredownstreamedgeoftheparkinglot.So,runoffwillneverconcentrateevenifthepermeableasphaltplugged.RunoffwouldsheetflowintothewetlandonthenorthsideoftheparkinglotandeithersoakintothegroundthereorsheetflowthroughthickforestandvegetationforseveralhundredfeettothewesttotheBlackRiver.16585.003.doc 15.cwi!ittteckit/&/cr’4eJtKftovy4t’KCRTSCommandCREATEanewTimeSeriesProductionofRunoffTimeSeriesProjectLocationSea-TacCompUtingSeries16585-lsmin-dev.tsfRegionalScaleFactor:1.00DataType:ReducedCreating15-minuteTimeSeriesFileLoadingTimeSeriesFile:C:\KCSWDM\KCDATA\STEI1SR.srfFlowPath;Length200.00ft©Slope0.012000Impervious0.55acresTotalArea:0.55acresPeakDischarge:0.580CFSat6:30onJan9inYear8StoringTimeSeriesFile:lESSS-lsmin-dev.tsfTimeSeriesComputedKCRTSCommandEntertheAnalysisTOOLSModuleAnalysisToolsCommandComputePEAKSandFlowFrequenciesLoadingStage/Dischargecurve:l65S5-lsmin-dev.tsfFlowFrequencyAnalysisTimeSeriesFile:l6585-lSmin-dev.tsfProjectLocation:Sea-TacFrequencies&PeakssavedtoFile:l6585-lsmin-dev.pksAnalysisToolsCommandRETURNtoPreviousMenuKCRTSCommandeXitKCRTSProgram FlowFrequencyAnalysisTimeSeriesFile:16585-lsmin-dev.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)Period0.31068/27/0118:000.6801100.000.9900.21589/17/0216:150.544225.000.9600.544212/08/0217:150.400310.000.9000.24778/26/041:000.32545.000.8000.314510/28/0416:000.31453.000.6670.325410/22/0510:000.31062.000.5000.400310/25/0622:450.24771.300.2310.6801i/ag/os6:300.21581.100.091ComputedPeaks0.63550.000.980 no’Doll,ROlSGMLPlOSP€tDIG.o‘6585flyPtonning/Butlding/PubticaCITYOFHABPERENGINEERINGPARKINGLOTRENTON700SWTh-ISThEETRENTON,WASHINGTONWorksDept.MNGPLAN21>r210C02100303a0CD0aS—01’=20’0amram210ICmCCD0aCC!1i”Ij_________F’1!U?•____________________I‘___________pi_____-———IIiCi/itcita*<—-ttwI____Ifl4A-±,-—%_\-4II/—=*=n==z2_N=aA1—-II____jrjJI*]frJIk.—L81B035E,:1/____-)ç*I\\F.éV.;/4frVciGASPIPLiI/‘1101-—16cij:;j/I;>4ft,\f///a.ol’uA•‘:///z—CCCci%4tI13-umU,4Zzimamamp3zNi>calJDz00rnrIn—ia-f0zCZOCzC-a>zC-arzIIIIIIII•••IIIItIIIii-.III/21I.>1•00210CDCDa0-u21011rm Figure4-Soils REFERENCE:USDA,NaturalResourcesConservationServiceLEGEND:Wo=WoodinvillesiltloamSeC=Seausitegravellysandyloam,6-15%slopesscale:For:JobNumberHorizontal:MTS.Vertical:WAHARPERENGINEERING16585&H4u1821572NDAVENUESOUTHRENTON,WASHINGTON9”4In,%LKENT,WA98032ZZ(425)251-6222Title:(425)251-87825fjCiViLENGINEERING,LANDPLANNING.<>SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:ii6000sii65a5lexhibitigmphicsii65a5soiLcdr 2.0CONDITIONSANDREQUIREMENTSSUMMARY 2.0CONDITIONSANDREQUIREMENTSSUMMARY2.1AnalysisoftheEightCoreRequirementsCoreRequirementNo.1:DischargeattheNaturalLocation.Response:Allsurfacewaterrunofffromthisnewdevelopmentwillbeinfiltratedintothesoilbelowthepermeableasphaltwiththeremainderofthesitefunctioningasitdoesunderexistingconditions.Therefore,thisrequirementismetCoreRequirementNo.2:Off-SiteAnalysis.Response:SinceinfiltrationofstormwaterrunoffistheproposedmeansofFlowControlBMPforthisprojectsitewithalloftherunoffinfiltratingreadilyintoground,noOff-SiteAnalysiswaspreparedforthissite.However,shouldrunoffeverovertoptheporouspavement,itwouldsheetflowtothewestintotheBlackRiverdrainagebasinattheBlackRiverPark.CoreRequirementNo.3:FlowControLResponse:FlowcontrolisbeingprovidedwiththisprojectintheformofaFlowControlBMPfortheentiredevelopedareaonthesitewhichmeetstherequirementsoftheCityofRentonforprojectsofthisnature.Therefore,thisCoreRequirementismet.CoreRequirementNo.4:ConveyanceSystem.Response:Thereisnoconveyancesystemproposedforthisdevelopment;therefore,thisCoreRequirementdoesnotapply.CoreRequirementNo.5:ErosionandSedimentControLResponse:Allerosionandsedimentcontrolrequirementsofthe2009KingCountySurfaceWaterDesignManualwillbefollowedwiththissiteasmodifiedbytheCityofRenton’samendments.Covermeasureswillbeprovided,clearinglimitswillbespecified,arockconstructionentrancewillbeinstalled,anddownstreamperimeterprotectionwillalsobeutilizedintheformofsiltfencestomaintainthatallrunoffleavingtheprojectsiteeitherinfiltrates,orshoulditconcentratebedispersedthroughthenativevegetationwithnosedimententrainedinthewater.CoreRequirementNo.6:MaintenanceandOperations.Response:AMaintenanceandOperationsPlanwillbepreparedwiththefinalpreparationoftheTechnicalInformationReportforthisproject.CoreRequirementNo.7:FinancialGuaranteesandLiability.Response:AllfinancialguaranteesandliabilitiesrequirementsoftheCityofRentonwillbefollowedforthisprojectaspertherequirementoftheCity.CoreRequirementNo.8:WaterQuality.Response:Theon-sitesoilsexhibitwaterqualitytreatmentcapabilitysincetheinfiltrationrateissosmall.Therefore,nofurtherwaterqualityrequirementisrequiredforthisproject.Thesiteislocatedinanaquiferrechargeareaandtheon-sitesoilswillprovidetherequiredtreatment.16585.003.dcc 2.2AnalysisoftheSixSpecialRequirementsSpecialRequirementNo.1:OtherAdoptedArea-SpecificRequirements.Response:Therearenoknownotheradoptedarea-specificrequirementsforthisareabytheCityofRentontothebestofourknowledge.SpecialRequirementNo.2:FloodHazardAreaDelineation.Response:TheBlackRiverislocatedwesterlyoftheprojectsiteandhasaFloodHazardAreaassociatedwithit.However,noneofthe100-yearfloodplainiswithintheprojectlimitsonthissite.SpecialRequirementNo.3:FloodProtectionFacilities.Response:ThisSpecialRequirementisnotapplicabletothisprojectsite.SpecialRequirementNo,4:SourceControl.Response:Theprojectsiteparkinglotwillhavetobesweptonaregularbasisandvacuumedaswellinordertomaintainthepermeabilityoftheasphaltonthisprojectsite.Thereshouldbenootherformsofpollutionotherthanoilandsedimentonthisareaoftheoveralldevelopment.SpecialRequirementNo.5:011Control.Response:Thisprojectdoesnotmeetthecharacteristicsofahigh-usesite;therefore,thisSpecialRequirementdoesnotapply.SpecialRequirementNo.6:AquiferProtectionArea.Response:ThisprojectisontheouterlimitfringeofanAquiferProtectionAreaandtheon-sitesoilsprovideadequatewaterqualitythroughinfiltrationthroughtheunderlyingsoilbelowthepermeableasphalt.Therefore,nofurtherliningoraquiferprotectionrequirementsapplytothisprojectsite.16585.003.doc 3.0OFF-SITEANALYSIS 3.0OFF-SITEANALYSISNooff-siteanalysiswaspreparedforthisprojectsiteasallrunoffgeneratedfromtheproposedparkinglotareawillbereadilyinfiltrated,includingrunofffromanyupstreambasindrainingontothepermeableasphalt.Asmallslopedareabetweentherailroadtracksandthepermeableasphaltwilldraindowntothepermeableasphalt;however,inthesizingofthepavementsection,thereisadequatesafetymeasuretoinfiltrateallstormwaterrunoffthatlandsonthepermeableasphalt.Therefore,nofurtherupstreamordownstreamanalysiswasperformedforthisproject.16585.003.doc FEMAMAP ZONEXAreasd(h,mr,dCondpb}n.REFERENCE:FederalEmergencyManagementAgency(PortionofMap53033CD976F,May1995)Scale:For:JobNumberHorizontal:N.TS.Vertical:N/AHARPERENGINEERING165851821572NDAVENUESOUTHRENTON,WASHINGTONKENT,WA98032In(425)251-6222Title:-,(425)251-8782FEMAMAP\-CIVILENGINEERING,LANDPLANNING,SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:l6OOOsI16585IexhibitIgmphics16565fema.cdr ASSESSOR’SMAP aREFERENCE:KingCountyDepartmentofAssessments(May2014)Scala:For:JobNumberHodzonM:N.ES.Vertical.N/AHARPERENGINEERING16585&4A,1821572NDAVENUESOUTHRENTON,WASHINGTON74fl%4%KENT,WA98032(425)251-6222Title:(425)251-8782\ASSESSORMAPCIVILENGINEERING,LANDPLANNING.SURVEYING,ENVIRONMENTALSERVICESDATE:08/20/14P:16OOOsIl6585IexhthitlgraphicsI16585amap.cdr SENSITIVEAREASFOLIOS REFERENCE:KingCountyMAP(2014):,i‘!hI..fLegend0Scale:For:JobNumberHorizontaLN.ZS.Vefljcat:HARPERENGINEERING16585e”4&•/1821572NDAVENUESOUTHRENTON,WASHINGTON.•KENLWA98032WZ(425)251-6222Title:CIVILENGINEERING,NDPNNING,MAPDATE08120/14(425)251-8782SENSITIVEAREAS&QSURVEYING,ENVIRONMENTALSERVICESCountyBoundarySAOStreamxMountainPeaks4fciHighwaysCs2PniniYStreetsfttCbnzSxmondIIi9hnyUndiLoLakesandLargeRiversParcelsStreamsSAGWetlandSAGLandslideSACCoal?MneSACSeismicSAOErosion2009ColarMdalPhotos(61n)2009ColorAerialPhotos(l2in)P:IlG000sIi65B5lexhibiLIgmphicsilGSSSsens.cdr 4.0FLOWCONTROLANDWATERQUALITYFACILITYANALYSISANDDESIGN 4.0FLOWCONTROLANDWATERQUALITYFACILITYANALYSISANDDESIGNA.ExistingSiteHydrologyUnderexistingconditionsthesiteishighlyvegetatedwithsecondgrowthforestandbrushyareas.Thereisanexistingwetlandlocatedinthenorthwestcorneroftheprojectsitewhichthesitecurrentlydrainstoifrunoffisnotinfiltratedorevaporatedpriortothat.B.DevelopedSiteHydrologyUnderdevelopedconditions24,000squarefeelofthesitewillhavepermeableasphaltappliedwithgradingoccurringinordertoprovideaparkinglotfortheproposeduseoftheexistingHarperEngineeringdevelopmentlocatedacrosstherailroadtracksandimmediatelysouthoftheprojectsite.Thispermeableasphalthasapavementsectionof24inchesincludingalsotherockandgravellayersbelowtheporousasphalt.Thiswasmorethanadequatetoinfiltrateallstormwaterrunoffgeneratedfromthepermeableasphaltandanycontributingarea.Pleaserefertothecalculationsonthefollowingpagesofthisreportforhowthatwassized.The24-inchpavementsectionwasselectedbecausetheparkinglotslopesfromsouthtonorthapproximately1.5feetinverticalrelief,whichleavesaneffectivestoragedepthinthesectionof6±inches.ThecomputeddepthoflivestoragebyKCRTScalculationswas0.17feet,sotheparkinglotshouldneverovertop.C.PerformanceStandardsTheKingCountyRunoffTimeSeriesmodelwasutilizedinsizingthepermeableasphaltpavementsectiononthisprojectsite.ThepermeableasphaltisaFlowControlBMPwhichmeetstherequirementsoftheCityofRentonforprojectsofthisnature.Waterqualityisnotrequiredastheon-sitesoilsexhibittraitsoftreatmenttypesoilsandthereisnoconveyancesystemproposedwiththisdevelopment.D.FlowControlSystemAsmentionedpreviously,theonlyflowcontrolsystemproposedforthisprojectistoutilizepermeableasphaltasaFlowControlBMP.E.WaterQualitySystemThereisnowaterqualitysystemproposedforthisproject.16585.003.doc KCRTSCALCULATIONSTOSIZETHEPOROUSASPHALT esgsHAFfCYPvicjLo1&f.Psra,c.*bePs.vttiitKCRTSCommand-O.79rIon)fermCREATEanewTimeSeriesProductionofRunoffTimeSerifr)O”5et?OflProjectLocationSea-TacComputingSeries:l6sS5infildev.tsf49IAfLRegionalScaleFactor:1.00c”VUI-DataType:Reduced/“etfcchvc_c-ehnilcythCreatingHourlyTimeSeriesFileI,LoadingTimeSeriesFile:C:\Kc_SWDM\Kc_DATA\STEI6OR.rnfImpervious0.55acresTotalArea:0.55acresPeakDischarge:0.260CFSat6:00onJan9inYearBStoringTimeSeriesFile:l6SBsinfildev.tsfTimeSeriesComputedKCRTSCommandEntertheAnalysisTOOLSModuleAnalysisToolsCommandComputePEAKSandFlowFreuenciesLoadingStage/Dischargecurve:l65Ssinfildev.tsfFlowFrequencyAnalysisTimeSeriesFile:l65Bsinfildev.tsfProjectLocation:Sea-TacFrequencies&PeakssavedtoFile:l658sinfildev.pksAnalysisToolsCommandRETURNtoPreviousMenuKCRTSCommandSizeaRetention/DetentionFACILITYEditFacilityCANCELLEDRetention/DetentionFacilityDesignSavingRetention/DetentionFacilityFile:l6sssinfil.rdfEndSizingRetention/DetentionFacilityKCRTSCommand FlowFrequencyAnalysisTimeSeriesFile:lss8binfildev.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFreouencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)Period0.13372/09/012:000.2601100.000.9900.11781/05/0216:000.200225.000.9600.163412/08/0218:000.163310.000.9000.13768/26/042:000.16345.000.8000.163310/28/0416:000.14253.000.6670.14251/18/0616:000.13762.000.5000.200210/26/060:000.13371.300.2310.26011/09/086:000.11781.100.091ComputedPeaks0.24050.000.980 FlowFrequencyAnalysisTimeSeriesFile:l6s85infilrdout.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)(if)Period0.00062/09/013:000.0000.171100.000.9900.00081/05/0217:000.0000.03225.000.9600.00042/27/038:000.0000.03310.000.9000.00078/26/043:000.0000.0345.000.8000.000310/28/0417:000.0000.0253.000.6670.00051/18/0614:000.0000.0262.000.5000.000210/26/061:000.0000.0271.300.2310.00011/09/0810:000.0000.0281.100.091ComputedPeakso.ooo0.1350.000.980 Retention/DetentionFacilityTypeofFacility:GravelInfiltrationTrenchFacilityLength:240.00ftFacilityWidth:100.00ftFacilityArea:24000.sq.ftEffectiveStorageDepth:0.50ftStage0Elevation:20.50ftStorageVolume:3600.cu.ftVerticalPermeability:200.00mm/inPermeableSurfaces:BottomRiserHead:0.50ftRiserDiameter:12.00inchesTopNotchWeir:NoneOutflowRatingCurve:NoneStageElevationStorageDischargePercolation(ft)(ft)(cu.ft)(ac-ft)(cfs)(cfs)0.0020.500.0.0000.0000.000.0320.53216.0.0GB0.0000.170.0520.55360.0.0080.0000.170.0820.58576.0.0130.0000.170.1020.60720.0.0170.0000.170.1320.63936.0.0210.0000.170.1520.651080.0.0250.0000.170.1820.681296.0.0300.0000.170.2020.701440.0.0330.0000.170.2320.731656.0.0380.0000.170.2520.751800.0.0410.0000.170.2820.782016.0.0460.0000.170.3020.802160.0.0500.0000.170.3320.832376.0.0550.0000.170.3520.852520.0.0580.0000.170.3820.882736.0.0630.0000.170.4020.902880.0.0660.0000.170.4320.933096.0.0710.0000.170.4520.953240.0.0740.0000.170.4820.983456.0.0790.0000.170.5021.003600.0.0830.0000.170.6021.103600.0.0830.3080.170.7021.203600.0.0830.8710.170.8021.303600.0.081.6000.170.9021.403600.0.0832.3900.171.0021.503600.0.0832.6700.171.1021.603600.0.0832.9300.171.2021.703600.0.0833.1600.171.3021.803600.0.0833.3800.171.4021.903600.0.0833.5900.171.5022.003600.0.0833.7800.171.6022.103600.0.0833.9700.171.7022.203600.0.0834.1400.17 20.67Ft1245.Cu-Ft0.029Ac-FtFlowFrequencyAnalysisTimeSeriesFile:l6s8sinfilrdout.tsfProjectLocation:Sea-Tac1.8022.303600.0.0834.3100.171.9022.403600.0.0834.4700.172.0022.503600.0.0834.6300.172.1022.603600.0.0834.7800.172.2022.703600.0.0834.9300.172.3022.803600.0.0835.0700.172.4022.903600.0.0835.2100.172.5023.003600.0.0835.3500.17InflowOutflowHydPeakStorageTargetCalcStageElev(Cu-Ft)(Ac-Ft)10.260.000.000.1720.671245.0.02920.14*******0.000.0220.52173.0.00430.20*******0.000.0320.53244.0.00640.16*******0.000.0320.53195.0.00450.16****“*0.000.0320.53202.0.00560.13“****0.000.0220.52166.0.00470.140.000.0220.52148.0.00380.12*******0.000.0220.52129.0.003Facilityl65ssinfildev.tsflesssinfilrdout.tsfRouteTimeSeriesthroughInflowTimeSeriesFile:OutflowTimeSeriesFile:Inflow/OutflowAnalysisPeakInflowDischarge:PeakOutflowDischarge:PeakReservoirStage:PeakReservoirElev:PeakReservoirStorage:0.260CFSat6:00onJan9inYear80.000CFSat10:00onJan9inYear80.17Ft---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)(ft)Period0.00062/09/013:000.0000.171100.000.9900.00081/05/0217:000.0000.03225.000.9600.00042/27/038:000.0000.03310.000.9000.00078/26/043:000.0000.0345.000.8000.000310/28/0417:000.0000.0253.000.6670.00051/18/0614:000.0000.0262.000.5000.000210/26/061:000.0000.0271.300.2310.00011/09/0810:000.0000.0281.100.091ComputedPeaks0.0000.1350.000.980 GRADINGANDDRAINAGEPLAN 5.0CONVEYANCESYSTEMANALYSISANDDESIGN 5.0CONVEYANCESYSTEMANALYSISANDDESIGNAsmentionedpreviously,thereisnoconveyanceproposedforthisdevelopment.Acalculationwasperformedassumingtheentireparkinglot’spermeablepavementhadfailedandusing15-minutetimestepsthe100-yearpeakflowfromtheparkinglotwillbe0.68cfs.ThisishighlyconservativesincebySBUHMethodologytheflowwouldcomputetolessthan0.5cfsforthisareaofKingCounty.Inaddition,curbbreaksareprovidedat6feetoncenteralongtheentiredownstreamedgeoftheparkinglot.So,runoffwillneverconcentrateevenifthepermeableasphaltplugged.RunoffwouldsheetflowintothewetlandonthenorthsideoftheparkinglotandeithersoakintothegroundthereorsheetflowthroughthickforestandvegetationforseveralhundredfeettothewesttotheBlackRiver.16585.003.doc 15.cwi!ittteckit/&/cr’4eJtKftovy4t’KCRTSCommandCREATEanewTimeSeriesProductionofRunoffTimeSeriesProjectLocationSea-TacCompUtingSeries16585-lsmin-dev.tsfRegionalScaleFactor:1.00DataType:ReducedCreating15-minuteTimeSeriesFileLoadingTimeSeriesFile:C:\KCSWDM\KCDATA\STEI1SR.srfFlowPath;Length200.00ft©Slope0.012000Impervious0.55acresTotalArea:0.55acresPeakDischarge:0.580CFSat6:30onJan9inYear8StoringTimeSeriesFile:lESSS-lsmin-dev.tsfTimeSeriesComputedKCRTSCommandEntertheAnalysisTOOLSModuleAnalysisToolsCommandComputePEAKSandFlowFrequenciesLoadingStage/Dischargecurve:l65S5-lsmin-dev.tsfFlowFrequencyAnalysisTimeSeriesFile:l6585-lSmin-dev.tsfProjectLocation:Sea-TacFrequencies&PeakssavedtoFile:l6585-lsmin-dev.pksAnalysisToolsCommandRETURNtoPreviousMenuKCRTSCommandeXitKCRTSProgram FlowFrequencyAnalysisTimeSeriesFile:16585-lsmin-dev.tsfProjectLocation:Sea-Tac---AnnualPeakFlowRates---FlowFrequencyAnalysisFlowRateRankTimeofPeak--Peaks--RankReturnProb(CFS)(CFS)Period0.31068/27/0118:000.6801100.000.9900.21589/17/0216:150.544225.000.9600.544212/08/0217:150.400310.000.9000.24778/26/041:000.32545.000.8000.314510/28/0416:000.31453.000.6670.325410/22/0510:000.31062.000.5000.400310/25/0622:450.24771.300.2310.6801i/ag/os6:300.21581.100.091ComputedPeaks0.63550.000.980 rimOSILIrioTSGMLWTCLSTkeiM16585PPP—SS—TTTTHARPERENGINEERINGPARKINGLOTADDmON7OOSWTEHSREETRENTON,WASHINGTONGRADt4G/PAWGPLAN/r00U0aU)z0a)0-c01-20’d0zmr>zm0>0mci)CE1DII1IiiIJIIhbfr’Nii4__a’H--.cV..J1*p.—t4(‘71I/r=______ø’*60w-S4jV/I’-V-‘F-_V7/—S365J/7//‘---GA5’UMSKtR(,?-o’trZZ..——(AOLWRY1%?‘161’I___I’If_DigsIA/-:0\/(i_-—/a—IT”____/CacJ-F-0(3000iDCDEl-Um3.202timomND>OJJAZ00rnr‘no00H02:1‘IiCcizC-a>zC-arz21.521.50IIIIeI’ggEa0aCCa.0Io+0•-aaa050rr,IolaI.>00CoU)z0-a33091rm21.721.2422.021.9026.226.1926.224.024.0322.0219026.0a>Wa.l,3_<—+U’90A0OSO‘L•Ii°°EUSUT—0•.J—‘-It-..ifU••_3S(A 6.0SPECIALREPORTSANDSTUDIES SOILSREPORT I____•EarthSolutionsNWLICDecember9,2014EarthSolutionsNWLLCES-2004.03•GeotechniolEngineering•ConstructionMonitoring•EnvironmentalSciencesHarperEngineeringdoBarghausenConsultingEngineers,Inc.nd18215—72AvenueSouthKent,Washington98032Attention:Mr.CostaPhilippidesSubject:PlanReviewPermeablePavementHarperEngineering700Southwest7thStreetRenton,WashingtonReference:BarghausenConsultingEngineers,Inc.IGrading/PavingPlanEarthSolutionsNW,LLCGeotechnicalEvaluationES-2004.02,datedAugust13,2014DearMr.Philippides:Inaccordancewithyourequest,EarthSolutionsNW,LLC(ESNW)haspreparedthisplanreviewfortheproposedpavementareasofthesubjectproperty.PlanReviewThesiteislocatedalongthenorthsideofSouthwest7thStreetinRenton,Washington.TheapproximatelocationofthepropertyisdelineatedontheVicinityMap(Plate1).Thesubjectareaconsistsofatriangular-shapedparcellocatedoffthenorthsideoftheexistingHarperEngineeringbuilding.Weunderstandnewparkingwillbeconstructedinthisarea.Gradeswillremainlargelyunchangedwiththeexceptionoftheegresswhichwillrequireconstructingaramptoclearanexistingabandonedrailwayline.Basedonreviewofthereferencedgrading/pavingplan,permeablepavementwillbeused.Thedetailforpermeablepavementonthereferenceddesignsheetincludesthefollowing:•3inchesporousasphaltpavementover;•3inchesClassDaggregate(coarsegrained)over;•4inchesoffreedrainingballastover;•Mirafi600Xgeotextileplacedonthenativesoil.1805-136thPlaceN.E.,Suite201Bellevue,WA98005•(425)449-4704•FAX(425)449-4711 IHarperEngineeringIdoBarghausenConsultingEngineers,Inc.ES-2004.03December912014Page2IBasedonourreviewofthereferencedplans,ourunderstandingoftheprojectscopeanduseIandinformationprovidedbyBarghausentherecommendationsinourreferencedreportwereincludedinthemostrecentdesignsubmittal.Wetrustthislettermeetsyourcurrentneeds.Ifyouhaveanyquestions,orifadditionalinformationisrequired,pleasecall.:ARmSOLUTIONSNW,LLC!oNAL1c’I7Rje1,L..,L..G.KyleftCampbell,P.E.Pject’MnagerPrincipalEarthSolutionsNW,LLC I•EarthSolutionsNWLLCAugust12,2014EarthSolutionsNWLLCES-2004.02•GeotechnicalEngineering•ConstructionMonitoringHarperEngineeringEnvironmentalSciencesciaCraftArchitects2505ThirdAvenue,Suite324Seattle,Washington98121Attention:Mr.ToddSchutzSubject:GeotechnicalEvaluationParkingAreaImprovementsHarperEngineering700Southwest7thStreetRenton,WashingtonReference:CraftArchitectsParkingAdditionPlan,SheetA0.1DatedJune30,2014DearMr.Schutz:Inaccordancewithyourequest,EarthSolutionsNW,LLC(ESNW)haspreparedthisgeotechnicalevaluationletterforthesubjectproperty.ProjectDescriptionThesiteislocatedalongthenorthsideofSouthwest7StreetinRenton,Washington.TheapproximatelocationofthepropertyisdelineatedontheVicinityMap(Plate1).Thesubjectareaconsistsofatriangular-shapedparcellocatedoffthenorthsideoftheexistingHarperEngineeringbuilding.Weunderstandnewparkingwillbeconstructedinthisarea.Gradeswillremainlargelyunchangedwiththeexceptionoftheegresswhichwillrequireconstructingaramptoclearanexistingabandonedrailwayline.Thefeasibilityofinfiltratingrunoffisalsobeinginvestigatedaspartoftheprojectplans.GeotechnicalEvaluationSubsurfaceConditionsAnESNWrepresentativeobserved,loggedandsampledfourtestpitsexcavatedwithintheproposedparkingareausingabackhoeandoperatorretainedbyourfirm.TheapproximatelocationsofthetestpitsaredelineatedontheTestPitLocationPlan(Plate2).Ageneralsoildescriptionisprovidedbelow.Pleaserefertothetestpitlogsforamoredetaileddescriptionofthesoilandgroundwaterconditionsencountered.7805-736thPlaceN.E.,Suite207Sellevue,WA98005•(425)44947Q4FAX(425)449-4711 HarperEngineeringES-2004.02c/aCraftArchitectsPage2August12,2014Ingeneral,silt(UnifiedSoilClassificationML)andsiltyfinesand(SM)alluvialdepositswereencounteredatthetestpitlocations.Thesiltwasthepredominatesoildepositandwasobservedtobeinaloosetomediumdensecondition.ThesiltysandwasencounteredattestpitlocationTP-4andwasoverlyingasiltdeposit.GroundwaterseepagewasobservedattestpitlocationTP-4atadepthofabouteightandone-halffeetbelowexistinggrade.Thisseepagelikelyrepresentsthelocalgroundwatertablegiventheproximityofalocalstreamabuttingthenorthpropertyline,andwewouldexpecttheleveltoriseduringtherainyFaN-Springmonths.InfiltrationRecommendationsWeconductedthreeEPAfallingheadinfiltrationtestswithinthenativesoildeposits,generallyatadepthofaboutthreefeetbelowexistinggrades.TheinfiltrationtestswereperformedattestpitlocationsTP-1throughTP-3.Basedontheresultsofthetesting,averageunfactoredinfiltrationratesof1.0inch/hour(TP-2andTP-3)and4.0inches/hour(TP-1)weremeasured.USDAtexturalanalysisofrepresentativesoilsamplesyieldedaloamclassification,withfinescontentsrangingfromabout87to94percentpassingtheNo.200sieve.Inouropinion,forpreliminarysitedesigns,afactoredinfiltrationrateof0.3inch/hourcanbeusedforLIDelements.Duetothelowinfiltrationrate,anoverflowprovisionshouldbeincludedindesigns.Basedonthegroundwaterconditionsobservedduringthefieldwork,infiltrationfacilitiesshouldnotextendbelowaboutthreefeetrelativetoexistinggrades.Thisprovisionisbasedonanestimateofseasonalhighgroundwaterthatrises2.5feetfromthelevelobservedduringthefieldworkof8.5feetandaseparationof3.0feet.PavementRecommendationsPavementrecommendationsinthissectionareforpreliminarydesignconsiderations.Itisassumedthatthemajorityofthetrafficloadingwillconsistofpassengervehicles,butthatoccasionalheavytrucksmayusethearea.Toensureadequatepavementperformance,thesubgradeshouldbeinafirmandunyieldingconditionwhensubjectedtoproofrollingwithaloadeddumptruck.Structuralfillinpavementareasshouldbecompactedtothespecificationsdetailedinthe“SitePreparationandEarthwork”sectionofthisreport.Itispossiblethatsoft,wet,orotherwiseunsuitablesubgradeareasmaystillexistafterbasegradingactivities.Areascontainingunsuitableoryieldingsubgradeconditionswillrequireremedialmeasuressuchascementtreatment,overexcavationandthickercrushedrockorstructuralfillsectionspriortopavement.Forrelativelylightlyloadedpavementssubjectedtoautomobiles,thefollowingpavementsectionscanbeconsidered:•Twoinchesofnotmixasphalt(HMA)placedoverfourinchesofcrushedrockbase(CRB),or;•TwoinchesofHMAplacedoverthreeinchesofasphalttreatedbase(ATB).EarthSolutionsNW,LLC HarperEngineeringES-2004.02doCraftArchitectsPage3August12,2014Heaviertrafficareassubjectedtooccasionaltrucktrafficgenerallyrequirethickerpavementsectionsdependingonsiteusage,pavementlifeexpectancy,andsitetraffic.Forpreliminarydesignpurposes,thefollowingpavementsectionscanbeconsideredfortheseareas.•ThreeinchesofHMAplacedoversixinchesofCR8,or;•ThreeinchesofACplacedoverfourandone-halfinchesofATB.TheHMA,ATBandCRBmaterialsshouldconformtoWSDOTspecifications.CityofRentonRoadStandardsmaysupersedetherecommendationsprovidedinthisdocument.RailroadCrossingEasementEgresswillbeprovidedviaacrossingeasementthatwillextendovertherailroadtracks.Themajorityofthecrossingwillbesupportedbyrailroadballastfill.Inthisrespect,roadwaysupportshouldbegood.Ingeneral,areasoutsidetheexistingrailroadballastfillshouldbepreparedinasimilarmannerasthosedescribedinthepavementsectionabove.Thereisthepotentialfordifferentialsettlementatthetransitionbetweentheballastfillandgeneralsitefill.Theroadwayfillwilltaperasitextendsoutsidetherailroadalignmentandthiswillreducethedifferentialsettlementtosomedegree.Tofurthermitigatetheeffectsofdifferentialsettlementintheegressarea,awovengeotextilesuchasMirafi600Xcanbeusedundernewfillareas.Thegeotextileshouldbeplacedsuchthatitextendsatleast10feetintotheballastfillareaand20feetintotheareasoutsideballastfill.Cementtreatmentofthesoilsoutsidetheballastareacanbeconsideredinlieuofusingageotextile.Wetrustthislettermeetsyourcurrentneeds,Ifyouhaveanyquestions,orifadditionalinformationisrequired,pleasecall.Sincerely,EARTHSOLUTIONSNW,LLC(2&i4i1,wgs-i(7oIIS4l,Lfr6KyleR.Campbell,P.E.ojecanagerPrincipalAttachments:Plate1—VicinityMapPlate2—TestPitLocationPlanTestPitLogs(TP-1throughTP-4)EarthSolutionsNW,LW MI—I___2441Iw,atIn1f•1-.4Ca__ _1Q¶lkf%\301d1WA4-JiJU)5ziitST—iRI!h1”cwouu.w,trj‘vFflW__ __ ___%!II3‘J98O’5\___-%2Oj____:dN.:‘%:t*.1a:__ _St..i_a--‘1.avGc‘.jJArh—..—.3...___I1.1.‘t%Reference:KingCounty,WashingtonMap656ByTheThomasGuideRandMcNally32ndEditionNORTHiEarthISolutionsNiVuctiIkSolutionsNWacEineering.ConstructionMonitoring-dEnvironmentalSciencesNOTE:Thisplatemaycontainareasofcolor.ESNWcannotberesponsibleforanysubsequentmisinterpretationoftheinformaUonresultingfromblack&whilereproductionsofthisplate.VicinityMapHarperEngineeringParkingAdditionRenton,WashingtonDrwn.GLSIDate08/11/2014(Proj.No.DateAug.2014Iiate2004.02CheckedSHA1 £—k”I£.,_.......j...,I—I25’Buffer———/—I_____________________-IIIIIIIUUH_-___II)H—II‘KI—Ifl2._I—I‘TP-.Z7’.TP-1iXZ‘\Z-71/Z“/___/\I<1/A/Existing//;\BuildingIILEGENDTP-1—!—ApproximateLocationofESNWTestPit,Proj.No.ES-2004.02,July2014——]SubjectSiteExistingBuildingWetlandArea(DelineatedByOthers)NOTE:Thegraphicsshownonthisplatearenotintendedfordesignpurposesorpredsescalemeasurements,butonlytoillustratetheappmmatetestlocationsrelativetotheapproximatelocationsofexistingandforproposedsitefeatures.Theinformationitustratedislargelybasedondataprovidedbytheclientatthetimeofourstudy.ESNWcannotberesponsibleforsubsequentdesignchangesorinterpretationofthedatabyothers.___________________________________________________________________I*LCt...LI030601201”=60’EarthSolutionsNWatL_JL.JScaleinFeett5NOTE:Thisplatemaycontainareasofcolor,ESNWcannotberesponsibleforanysubsequentmisinterpretationoftheinformationresultingfromblack&whitereproductionsofthisplate.TestPitLocationPlanHarperEngineeringParkingAdditionRenton,WashingtonDrwn.GLSDate08/11/2014Proj.No.2004.02CheckedSHADateAug.2014Plate2 EarthSolutionsNWLLCSOILCLASSIFICATIONCHARTSYMBOLSTYPICALMAJORDIVISIONSGRAPHLETrERDESCRIPTIONS‘,S.—.WELL-GRADEDGRAVELS,GRAVEL-CLEANGWSANDMIXTURES,LITREORNoGRAVELGRAVELSbabAND•.iFINESGRAVELLYPOORLY-GRADEDGRAVELS.SOILSD3°5<GPGRAVEL-SANDMIXTURES.LITRE(LrrRE0RNOFINES)bOo°.cORNOFINESCOARSEQgGRAINEDGRAVELSWITHCtZb°GMSILTYGRAVELS,GRAVEL-SAND-SOILSMOREThAN50%FINESôU—’dbSILTMIXTURESOFCOARSEIFRACTIONRETAINEDONNO.CLAYEYGRAVELS,GRAVEL-SAND-4SIEVE(APPRECLABLECLAYMIXTURESAMOUNTOFFINES)GCCLEANSANDSSWWELL-GRADEDSANDS,GRAVELYSANDS,LITREORNoFiNESMORETHAN50%SANDoffMATERIALISANDNO.200SIEVESOILSLARGERThANSANDYPOORLY-GRADEDSANDS,GRAVELLYSAND,L1fl12ORNOSIZE(LITREORNOFINES)PINESSANDSWITHSMSILTYSANDS,SAND-SILTMIXTURESOPCOARSEFRACTIONPASSINGONN04SIEVE(APPRECIABLEscCLAYEYSANDS.SAND-CLAYMIXTURESAMOUNTOFFINES)MORETHAN50%FINESCLAFINESANDSORCLAYINORGANICSILTSANDVERYFINEMLSANDS,ROCKFLOUR,SILTYORSILTSWIThSLIGHTPLASTICITYINORGANICCLAYSOFLOWTOSILTSMEDIUMPLASTICITY.GRAVELLYFINEANDLIQUIDLIMITLESSTHAN50CLAYS,SANDYCLAYS,SILTY/J/CL___GRAINEDCLAYSCLAYS.LEANCLAYSSOILS————OLORGANICSILTSANDORGANICSILTYCLAYSOFLOWPLASTICITYMOREThAN58%INORGANICSILTS.MICACEOUSOROFMATERIALISSMALLERThANSLTYSOILSANDGREATERTHAN50JMRDIATOMACEOUSFINESANDORNO.200SIEVESIZESILTSLIaUIDLIMITCRINORGANICCLAYSOFHIGHPLASTICITYCLAYS——-----OHORGANICCLAYSOFMEDIUMTOHIGHPLASTICITY.ORGANICSILTS—.-.--nHIGHLYORGANICSOILS-———.PTPEAtHUMUS.SWAMPSOILSWITHHIGHORGANICCONTENTSL’tktDUALSYMBOLSareusedtoindicateborderlinesoilClassifications.Thediscussioninthetextofthisreportisnecessaryforaproperunderstandingofthenatureofthematerialpresentedintheattachedlogs. IciIIrEarth‘SolutionEarthSolutionsNWTESTPITNUMBERTP-11805-136thPlaceN.E.,Suite201Bellevue,Washington98005PAGE1OF1Telephone:425-449-4704Fax:425-4494711CLIENTHarperEngineeringPROJECTNAMEHarperEngineeringParkingAdditionPROJECTNUMBER2004-2PROJECTLOCATiONRenton,WashingtonDATESTARTED7/29114COMPLETED7/29/14GROUNDELEVATIONTESTPITSIZEEXCAVATIONCONTRACTORWahersonExcavatingGROUNDWATERLEVELS:EXCAVATIONMETHODATTIMEOFEXCAVATION—LOGGEDBYSI-iACHECKEDBYSHAATENDOFEXCAVATION—NOTESDepthofTopsoil&Sod8”:blackberrybushesAFTEREXCAVATION—rTESTSMATERIALDESCRIPTIONw00D‘CU,0TPSL0.5TOPSOILBrownSILT,stiff,moistMC=2500%Fines87.40%MC=36.90%ML510[USDAClassification:tanLOAM]-lightIronoxidestaining-sandlensing10.0Testpitterminatedat10.0feetbelowexistinggrade.Nogroundwaterencounteredduringexcavation.Bottomoftestpitat10.0ftet EarthSolutionsNW1805-136thPlaceNE.,Suite2OlTESTPITNUMBERTP-2Bellevue,Washington98005PAGE1OF1Telephone:425449.4704Fax:4254494711‘SolutionNWijcCLIENTHarperEngineeringPROJECTNAMEHarperEngineeringParkingAdditionPROJECTNUMBER2004-2PROJECTLOCATiONRenton,WashingtonDATESTARTED7/29/14COMPLETED7/29/14GROUNDELEVATIONTESTPITSIZEEXCAVATIONCONTRACTORWattersonExcavatingGROUNDWATERLEVELS:EXCAVATIONMETHODAT‘rIMEOFEXCAVATION—LOGGEDBYSHACHECKEDBYSI-IAATENDOFEXCAVATION—NOTESDepthofTopsoil&Sod8”:blackberrybushesAFTEREXCAVATION—ITESTS°-8MATERIALDESCRIPTION0<0)0TPSL£‘0.5TOPSOILIaI!510MC=37.00%MC=33.00%ML11.0BrownSILT,stiff,moist-increasedsiltcontent-sandlensing,increasedmoisturecontentTestpaterminatedat11.0feetbelowexistinggrade.Nogroundwaterencounteredduringexcavation.Bottomoftestpitat11.0feet. ICICC:jEarthSottitionrPSL0.5TOPSOIL9.0Testpitterminatedat9.0feetbelowexistinggrade.Nogroundwaterencounteredduringexcavation.Bottomoftestpitat9.0feet.BarthSolutionsNW1805-136thPlaceN.E.,Suite201TESTPITNUMBERTP—3Betlevue,Washington98005PAGE1OF1Telephone;425449.4704Fax;425449471ICLIENTHarperEngineeringPROJECTNAMEHarperEngineeflngParkingAdditionPROJECTNUMBER2004-2PROJECTLOCATIONRenton,WashingtonDATESTARTED7/29/14COMPLETED7)29/14GROUNDELEVATIONTESTPITSImEXCAVATIONCONTRACTORWattersonExcavatingGROUNDWATERLEVELS:EXCAVATIONMETHODATTIMEOFEXCAVATION—LOGGEDBYSI-tACHECKEDBYSHAATENDOFEXCAVATION—NOTESDepthofTopsoil&Sod8”;baresoilAFTEREXCAVATION—zTESTSMATERIALDESCRIPTIONCz<LU0MC=18.20%BrownSILT,stiff,moist-becomesverystiff,lightironoxidestaining5ML ;Earth‘SolulionMiLtEarthSolutionsNW1605-136thPlaceN.E.!Suite201TESTPITNUMBERTP4Bellevue,Washington98005PAGE1OF1Telephone:4254494704Fax:4254494711CLIENTHarperEngineeringPROJECTNAMEHarperEngIneeringParkingAdditionPROJECTNUMBER2004-2PROJECTLOCATIONRenton,WashingtonDATESTARTED7/29/14COMPLETED7/29/14GROUNDELEVATIONTESTPITSIZEEXCAVATIONCONTRACTORWattersonExcavatingGROUNDWATERLEVELS:EXCAVATiONMEThODVATliMEOFEXCAVATION8.5ftLOGGEDBYSHACHECKEDBYSHAATENDOFEXCAVATION—NOTESDepthofTopsoil&SodB”:baresoilAFTEREXCAVATION—LU_-sTESTS3MATERIALDESCRIPTION00zrPSL0.5TOPSOILBrownsiltySAND!mediumdense,moistMc35.10%MC=40.10%Fines=94.10%Mc41.00%510SM6.0GraySILT,mediumstiff,moisttowetML85(USDAClassification:grayLOAM]-BrownpoorlygradedSANDwithsilt,mediumdensetodense!wetY10.0Testpitterminatedat10.0feetbelowexistinggrade.Groundwatertableencounteredat8.5feetduringexcavation.Bottomoftestpitat10.0feet.ICCCd,I0a ICInInzItHzIn0In0.EarthSolutionsNWGRAINSIZEDISTRIBUTION1805-136thPlaceN.E.,Suite201Bellevue,WA98005Telephone:425-284-3300I*Earth‘SolutionsNWuCLIENTHarperEnginecingrioCraftArchitectsPROJECTNAMEHarperEngineedngPROJECTNUMBERES-2004.02PROJECTLOCATIONRentonU.S.SIEVEOPENINGININCHESIU.S.SIEVENUMBERS64321.513(41/23(6366q1420Q4O5050“CIIIIII’I’—I100140200KYDROMETER;858075-- - - - - . - - - -—- -70-———••-———.-- .——65-———.L—__60-—— ---—— .————55_50——. -——.— •-. -—•—————-40————. .——— -—35————.———..-;-——30————----————..t——25--——• ---—20-———---——:—15--——.-——10-———. - --———.-———5-——--—--—.--————.————o________..--————.————1001010.10.01GRAINSIZEINMILLIMETERSCOBBLESGRAVELSANDSILTORCLAYLcoarsefinecoarsemediumfinenFTP46.0ff.0.001USDA:GrayLoam.USCS:Silt,ML.Lu‘UC,SpecimenIdentificationClassificationLLPLP1CcCUTP-13.0ff.USDA:TanLoam.USCS:Silt1MLSpecimenIdentification0100D6D030010%Grav&%Sand%Silt%CIay2T1’13.0ft4.750.012.687.4TP46.0ff.20.05.994.1C, 7.0OTHERPERMITS 7.0OTHERPERMITSOtherpermitsforthisprojectsiteinclude:•ClearandGradePermit•SiteDevelopmentPermit16585.003doc 8.0CONSTRUCTIONSTORMWATERPOLLUTIONPREVENTIONPLANANALYSISANDDESIGN 8.0CONSTRUCTIONSTORMWATERPOLLUTIONPREVENTIONPLAN(CSWPPP)ANALYSISANDDESIGNA.ErosionandSedimentControl(ESC)PlanAnalysisandDesignThe2009KingCountySurfaceWaterDesignManualAppendixDasmodifiedbytheCityofRentonwillbefollowedinprovidingerosioncontrolfacilitiesforthisprojectsite.Covermeasuresarespecified,clearinglimitsareshown,andperimeterprotectionintheformofsiltfencewillbeinstalledaroundtheperimeterofthesite.Thissiteislessthan1acreinsizefortheareathatisbeingdeveloped.Therefore,asedimenttraporsedimentpondisnotrequired;alsobecausetheon-sitesoilswilllikelyinfiltraterunoffthatlandsonthemunlessitbecomesconcentrated.Then,thesiltfencewillactadeterrenttothespreadingofsediment-ladenwaterdownstream.Inaddition,onthedownstreamsideofthesiltfenceisthickvegetationthatwillactasdispersionforrunofffromthisprojectsite.B.StormwaterPollutionPreventionandSpill(SWPPS)PlanDesignWhenthepavementplacementmachineisonthesiteitwillhavetobemaintained.Anoilspillcouldoccur;however,themaintenanceofthisdevicemustbeperformedoveranimpermeablelinerareaofthesiteinordertopreventcontaminantsfromenteringthegroundwater.Inaddition,concretewillbepouredtoprovideextrudedcurbsurroundingtheperimeteroftheasphaltpavement.Therecouldbepollutantsdischargedwiththecleaningoftheconcretetruck;however,thiswillhavetooccurinalocationthatcanbecleanedupreadilywithnoimpacttotheaquiferfromconcrete.Thosearetheonlyanticipatedpollution-creatingsourcesontheprojectsite.16585.003.doc 9.0BONDQUANTITIES,FACILITIESSUMMARIES,ANDDECLARATIONOFCOVENANT NOTAPPLICABLE 10.0OPERATIONSANDMAINTENANCEMANUAL NOTAPPLICABLE