DEVELOPMENT BEST MANAGEMENT PRACTICES HANDBOOK

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  • DEVELOPMENTBESTMANAGEMENTPRACTICESHANDBOOK LOWIMPACTDEVELOPMENTMANUAL PARTB

    PLANNINGACTIVITES June2011 4THEDITION

  • THISPAGEINTENTIONALLYLEFTBLANK

  • This4theditionisarevisiontothe3rdeditiontoreflectthenewlyadoptedLowImpactDevelopment

    (LID)requirementsthattakeeffectMay12,2012.Thehandbookwascreatedunderthedirectionof

    theCityofLosAngeles,who is fully responsible for the contentwithinanda technical committee

    comprisedoftheDepartmentsofPlanning,BuildingandSafety,andWaterandPower,theBureausof

    Street Services and Engineering, and individuals from the development, environmental, and

    consultantcommunity.

    ThisDevelopmentBestManagementPracticesHandbook,PartBPlanningActivities,4theditionwas

    adoptedbytheCityofLosAngeles,BoardofPublicWorksonJuly1,2011asauthorizedbySection

    64.72oftheLosAngelesMunicipalCodeapprovedbyOrdinanceNo.173494.

  • THISPAGEINTENTIONALLYLEFTBLANK

  • TABLEOFCONTENTS

    SECTION1:INTRODUCTION.............................................................................................................. 1

    1.1 BACKGROUND ..........................................................................................................................................11.2 USERSOFTHEHANDBOOK................................................................................................................21.3 HANDBOOKPURPOSEANDSCOPE.................................................................................................21.4 LEGALFRAMEWORK.............................................................................................................................21.5 DEVELOPMENTPLANNINGPROGRAM.........................................................................................4

    SECTION2:PROJECTREVIEWANDPERMITTINGPROCESS .............................................. 7

    2.1 PLANAPPROVALPROCESS ................................................................................................................72.2 INSPECTIONPROCESS....................................................................................................................... 112.3 BMPMAINTENANCE .......................................................................................................................... 112.4 MUNICIPALPROJECTS....................................................................................................................... 12

    SECTION3:STORMWATERMANAGEMENTMEASURES ................................................... 13

    3.1 LOWIMPACTDEVELOPMENT(LID)PLAN .............................................................................. 133.2 STANDARDURBANSTORMWATERMITIGATIONPLAN(SUSMP)................................ 213.3 SITESPECIFICMITIGATION............................................................................................................ 213.4 SOURCECONTROLMEASURES...................................................................................................... 21

    SECTION4:BMPPRIORITIZATIONANDSELECTION.......................................................... 24

    4.1 PRIORITIZATIONOFBMPSELECTION....................................................................................... 244.2 INFILTRATIONFEASIBILITYSCREENING ................................................................................ 254.3 CAPTUREANDUSEFEASIBILITYSCREENING ....................................................................... 294.4 INFILTRATIONBMPS ......................................................................................................................... 334.5 CAPTUREANDUSEBMPS ................................................................................................................ 44

    SECTION5:OFFSITEMITIGATIONMEASURES...................................................................... 59

    5.1 OFFSITEMITGATIONMEASURES................................................................................................. 59

  • TABLEOFCONTENTS

    APPENDICESAppendixA DevelopmentPlanningOrdinances

    AppendixB CEQAMitigationMeasures

    AppendixC ContactList

    AppendixD PlanCheckReviewForms

    AppendixE SmallScaleResidentialPrescriptiveMeasures

    AppendixF AllOtherDevelopmentVolumeDesignCalculations

    AppendixG StandardUrbanStormwaterMitigationPlan(SUSMP)

    AppendixH SiteSpecificMitigationMeasures

    AppendixI LADepartmentofBuildingandSafetyStormwaterInfiltrationGuidelines

    AppendixJ UpperLosAngelesRiverWatermasterRequirements

    AppendixK CountyofLADepartmentofPublicHealthPolicyandOperationsManual

    LISTOFTABLESTable3.1 SummaryofSiteSpecificSourceControlMeasureDesignFeatures

    Table4.1 InfiltrationFeasibilityScreening

    Table4.2 CaptureandUseFeasibilityScreening

    Table4.3 LandscapedAreaCategorization

    Table4.4 InfiltrationBMPDesignCriteria

    Table4.5 BiofiltrationBMPDesignCriteria

    Table4.6 SwaleBaseWidthandLength(PerUnitCatchmentArea)

    Table4.7 CheckDamSpacingRequirementsforSwales

    LISTOFFIGURESFigure3.1 SmallScaleResidentialBMPSchematic

    Figure3.2 RequirementsforResidentialDevelopmentof4UnitsorLess

    Figure3.3 RequirementsforAllOtherDevelopments

  • TABLEOFCONTENTS

    ACRONYMSANDABBREVIATION ASCE AmericanSocietyofCivilEngineersBMP BestManagementPracticesBOE BureauofEngineeringBOS BureauofSanitationCGPL CaliforniaGeneralPlanLawCEQA CaliforniaEnvironmentalQualityActCZARA CoastalZoneActReauthorizationAmendmentsof1990C&A CovenantandAgreementDCP LosAngelesDepartmentofCityPlanningDPW LosAngelesDepartmentofPublicWorksEAF EnvironmentalAssessmentFormEIR EnvironmentalImpactReportEPA UnitedStatesEnvironmentalProtectionAgencyESA EnvironmentallySensitiveAreaETWU EstimatedTotalWaterUseCGPL CaliforniaGeneralPlanLawHC HydrocarbonsLADBS LosAngelesDepartmentofBuildingandSafetyLID LowImpactDevelopmentMAWA MaximumAppliedWaterAllowanceMEP MaximumExtentPracticable(statutorystandard)MND MitigatedNegativeDeclarationMS4 MunicipalSeparateStormSewerSystemsNPDES NationalPollutantDischargeEliminationSystemO&G OilandGreaseO&M OperationandMaintenancePCIS PlanCheckandInspectionSystemRGO RetailGasolineOutletsRWQCB LosAngelesRegionalWaterQualityControlBoardSIC StandardIndustrialClassificationSOR StormwaterObservationReportSWRCB StateWaterResourcesControlBoard(California)SUSMP StandardUrbanStormwaterMitigationPlanULARA UpperLosAngelesRiverAreaULARWM UpperLosAngelesRiverAreaWatermasterWEF WaterEnvironmentFederationWPD WatershedProtectionDivision

  • Section 1: Introduction |1

    CITYOFLOSANGELESLOWIMPACTDEVELOPMENTBESTMANAGEMENTPRACTICESHANDBOOK

    SECTION1:INTRODUCTION 1.1 BACKGROUND Urban runoff discharged frommunicipal storm drain systems has been identified by local,regional,andnationalresearchprogramsasoneoftheprincipalcausesofwaterqualityimpactsinmosturbanareas.Urbanrunoffpotentiallycontainsahostofpollutantssuchas trashanddebris,bacteriaandviruses,oilandgrease,sediments,nutrients,metals,andtoxicchemicals.These contaminants can adversely affect receiving and coastalwaters, associatedbiota, andpublic health. An epidemiological study by the SantaMonica Bay Restoration Project wasconducted to investigate possible health effects of swimming in SantaMonica Bay. Studyresultsindicatedthatindividualsswimmingnearflowingstormdrainoutletshaveagreaterriskofdevelopingvarioussymptomsofillnessescomparedtothoseswimming400yardsawayfromthe samedrains. In addition,oil and grease fromparking lots, leakingpetroleumorotherhydrocarbon products, leachate from storage tanks, pesticides, cleaning solvents, and othertoxic chemicals can contaminate stormwater and be transported downstream into waterbodies and receivingwaters. Fertilizer constituents from lawns and golf courses or leakingseptictankscancausealgalblooms.Disturbancesofthesoilfromconstructioncanallowsiltto wash into storm channels and receiving waters, making them muddy, cloudy, andinhospitable tonaturalaquaticorganisms. Heavymetalsare toxic toaquaticorganismsandmanyartificialsurfacesoftheurbanenvironmentsuchasgalvanizedmetal,paint,orpreservedwood containingmetals contribute to stormwater pollution as the surfaces corrode, flake,dissolve,ordecay.Land development and construction activities significantly alter drainage patterns andcontribute pollutants to urban runoff primarily through erosion and removal or change ofexisting natural vegetation. When homes, shops, work places, recreational areas, roads,parking lots,andstructuresarebuilt, increasedflowsaredischarged into localwaterways. Astheamountofimpervioussurfaceincreases,waterthatoncepercolatedintothesoilnowflowsoverthelandsurface.Accordingly,increasesinimpervioussurfacescanincreasethefrequencyandintensityofstormwaterflowsthroughawatershed.Flowfromrainstormsandotherwateruseswash rapidly across the impervious landscape, scouring the surface of various kinds ofurban pollutants such as automotive fluids, cleaning solvents, toxic or hazardous chemicals,detergents, sediment,metals, bacteria, pesticides, oil and grease, and foodwastes. Thesepollutants,unfiltered andunfettered, flow through stormwater infrastructure andultimatelycontaminatereceivingwaters.

  • Section 1: Introduction |2

    CITYOFLOSANGELESLOWIMPACTDEVELOPMENTBESTMANAGEMENTPRACTICESHANDBOOK

    1.2 HANDBOOKPURPOSEANDSCOPE ThepurposeofthishandbookistoassistdevelopersincomplyingwiththerequirementsoftheDevelopmentPlanningProgramregulationsoftheCitysStormwaterProgram. ThishandbooksummarizestheCitysprojectreviewandpermittingprocess, identifiesstormwatermitigationmeasures,andreferencessourceandtreatmentcontrolBMPinformation.Itprovidesguidanceforindividualsinvolvedinnewdevelopmentandredevelopmentprojects.Thetargetaudienceforthishandbookincludesdevelopers,designers,contractors,homeowners,andCitystaffsthatare engaged in planchecking, permitting, and inspections related to land developmentactivities. This handbook also contains the necessary forms andworksheets required to becompletedbythedeveloperforapproval. 1.3 LEGALFRAMEWORK With public concern growing over urban runoff and stormwater pollution, local, state, andfederal agencies have devised plans to control and/or treat stormwaterrelated pollutionbeforeitreachesreceivingwaters.TheFederalCleanWaterActistheprincipalvehicleforcontrolofstormwaterpollution.UndertheFederalCleanWaterAct,eachmunicipalitythroughoutthenation is issuedastormwaterpermit through theNational PollutantDischarge Elimination System (NPDES) program. Theprimarygoalofeachpermitistostoppolluteddischargesfromenteringthestormdrainsystemand local receiving and coastal waters. In California, the NPDES stormwater permittingprogramisadministeredbytheStateWaterResourcesControlBoard(SWRCB)throughitsnineRegionalBoards.On July 5, 1996, the Los Angeles RegionalWaterQuality Control Board (Regional Board orRWQCB)adoptedOrderNo.96054theNPDESStormwaterPermit(Permit)fortheCountyofLosAngelesandcitieswithin (NPDESNo.CAS614001). ThePermitwas issuedtoLosAngelesCounty (PrincipalPermittee) and84 cities (Permittees) to reducepollutantsdischarged fromtheirMunicipalSeparateStormSewerSystems(MS4)totheMaximumExtentPracticable(MEP)statutorystandard. OnDecember13,2001,theRegionalBoardadoptedanewPermit(OrderNo.01182,NPDESPermitNo.CAS004001).The requirement to implement the Permit is based on federal and state statutes, includingSection 402(p) of the Federal Clean Water Act, Section 6217 of the Coastal Zone ActReauthorizationAmendments (CZARA)of1990,and theCaliforniaWaterCode. The FederalCleanWater Act amendments of 1987 established a framework for regulating stormwaterdischarges frommunicipal, industrial, and construction activities under theNPDES program.Theprimaryobjectivesofthestormwaterprogramrequirementsareto:

  • Section 1: Introduction |3

    CITYOFLOSANGELESLOWIMPACTDEVELOPMENTBESTMANAGEMENTPRACTICESHANDBOOK

    Effectivelyprohibitnonstormwaterdischarges,and

    Reduce thedischargeofpollutants from stormwater conveyance systems to theMEPstatutorystandard.

    Based on the Permit issued by the Regional Board, the County and its copermittees arerequiredtodevelopandimplementanumberofstormwatermanagementprogramsdesignedto reduce pollutants in stormwater and urban runoff. These programs are the PublicInformation and Participation Program, Industrial/Commercial Facilities Program, IllicitConnections and Illicit Discharges Elimination Program, Development Planning Program,DevelopmentConstructionProgram,PublicAgencyActivitiesProgram,andtheMonitoringandReportingProgram.Oneoftheseprograms,theDevelopmentPlanningProgram,focusesonpreventingpollutantsthat couldbe generated from new development and redevelopmentprojects from reachingstormwater conveyance systems and receiving waters. Under this program, the RWQCBdeveloped requirements for the StandardUrban StormwaterMitigationPlan (SUSMP)whichrequiresspecificdevelopmentandredevelopmentcategoriestomanagestormwaterrunoff.In2002,theCityofLosAngelesimplementedtheSUSMPprogramrequiringalltheaffectedlanddevelopmentprojectstocaptureortreatstormwaterrunoff.ArelativelyrecentstormwatermanagementapproachaimedatachievingthisgoalistheuseofLow ImpactDevelopment(LID).Overthepast10years,LIDpracticeshavereceived increasedattention and implementation,becoming a leadingpractice for stormwatermanagement. Inrecognitionofthis,recentactionsbytheRWQCB,SWRCB,andUSEPAhaveprioritizedtheuseof LID as the preferred approach to stormwatermanagement, including for the purpose ofwaterqualitycompliance.LID isa stormwatermanagement strategy that seeks tomitigate the impactsof increases inrunoffandstormwaterpollutionascloseto itssourceaspossible. LIDcomprisesasetofsitedesign approaches andBestManagementPractices (BMPs) thatpromote theuseofnaturalsystems for infiltration,evapotranspiration, anduseof stormwater. These LIDpractices caneffectivelyremovenutrients,bacteria,andmetalsfromstormwaterwhilereducingthevolumeand intensityof stormwater flows. With respect tourbandevelopment and redevelopmentprojects, itcanbeappliedonsitetomimicthesitespredevelopmentdrainagecharacteristics.Through theuseof various infiltration techniques, LID is geared towardsminimizing surfacearea that produces large amounts of runoff and does not allowwater to infiltrate into theground. Where infiltration is infeasible, the use of bioretention, rain gardens, vegetatedrooftops,andrainbarrelsthatwillstore,evaporate,detain,and/ortreatrunoffcanbeused.

  • Section 1: Introduction |4

    CITYOFLOSANGELESLOWIMPACTDEVELOPMENTBESTMANAGEMENTPRACTICESHANDBOOK

    InNovember2011,theCityadoptedtheStormwaterLIDOrdinance(Ordinance#181899)withthestatedpurposeof: Requiring the use of LID standards and practices in future developments and

    redevelopmentstoencouragethebeneficialuseofrainwaterandurbanrunoff;

    Reducingstormwater/urbanrunoffwhileimprovingwaterquality;

    Promotingrainwaterharvesting;

    Reducingoffsiterunoffandprovidingincreasedgroundwaterrecharge;

    Reducingerosionandhydrologicimpactsdownstream;and

    Enhancingtherecreationalandaestheticvaluesinourcommunities.InadditiontoSUSMPtheCity institutionalizedtheuseofLIDtechniquesfordevelopmentandredevelopment projects. Subsequent to the adoption of the Stormwater LIDOrdinance, thishandbookhasbeenamended to require stormwatermitigation foramuch largernumbero...

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