LEED Standards and Stormwater Management Low Impact ...€¦ · foundations may be used for...
Transcript of LEED Standards and Stormwater Management Low Impact ...€¦ · foundations may be used for...
LEED Standards and Stormwater ManagementLow Impact Development
Yizhou Wang
Presentation Outline
• ConceptandHarmofStormwater
• LowImpactDevelopment
• LeadershipinEnergyandEnvironmentalDesign(LEED)
NewConstructionandMajorRenovation(NC)
Existing Buildings: Operations and Maintenance(BO&M)
NeighborhoodDevelopment(ND)
• PotentialImprovementofLEED
• ComparisonwithOtherSystems
EarthCraftCertificationSystem
EPA Guidance
• ApplicationofLEEDonRichmond,VA
ConceptandHarmsofStormwater
Waterthatoriginatesduringsharpprecipitation events and snowmelt
• Flowsdirectlyintosurfacewaterways
• Channeledintostormsewers,eventuallydischargetosurfacewaters
Concept:
Harms:
• Largevolumeandsharptimingoftherunoffwater
floodcontrolwatersupplyerosion
• Generationandtransmittionofcontaminants
waterpollutionhealthcarecrisisdrinkingwatershortage
Low Impact Development
Adesignstrategythatcreatesafunctionallyequivalenthydrologicsitedesignwiththe
goalofmaintainingorreplicatingthepre-developmenthydrologicregime, primarily
to counterhuman-inducedchangestotheenvironment.
LID:
Five Basic Steps:
1. Conservation
2. Minimization
3. PredevelopmentTimeofConcentration
4. Redevelopmentcurveandrunoffvolume
5. Pollutionprevention
LeadershipinEnergyandEnvironmentalDesignAvoluntary,consensus-based,market-drivenprogramthatprovidesthird-partyverificationofgreenbuildings.
SystemStructure:
LEEDSystemandLID
Tolimitdisruptionofnaturalhydrologybyreducingimperviouscover,increasingon-siteinfiltration,reducingoreliminatingpollutionfromstormwaterrunoffandeliminatingcontaminants.
NewConstruction:SiteSelection(SS)Credit6.1
1.SiteswithExistingImperviousness50%orLess• Implementastormwatermanagementplanthatpreventsthepostdevelopmentpeakdischargerateandquantityfromexceedingthepredevelopmentpeakdischargerateandquantityforthe1-and2-year24-hourdesign storms Or• Implement a stormwatermanagement plan that protects receiving stream channels from excessiveerosion.Thestormwatermanagementplanmust includestreamchannelprotectionandquantitycontrolstrategies2.SiteswithExistingImperviousnessGreaterThan50%• Implementastormwatermanagementplanthatresultsina25%decreaseinthevolumeofstormwaterrunofffromthe2-year24-hourdesignstorm.
• Designtheprojectsitetomaintain natural stormwater flowsbypromotinginfiltration.Specifyvegetated roofs,pervious pavingandothermeasures tominimize impervioussurfaces.Reusestormwater fornon-potableusessuchaslandscapeirrigation,toiletandurinalflushing,andcustodialuses.
Requirement:
PotentialTechnologies&Strategies:
LEEDSystemandLIDNewConstruction:SiteSelection(SS)Credit6.2
Tolimitdisruptionandpollutionofnaturalwaterflowsbymanagingstormwaterrunoff.
Implementastormwatermanagementplanthatreducesimperviouscover,promotesinfiltrationandcapturesandtreatsthestormwaterrunofffrom90%oftheaverageannualrainfall1usingacceptablebestmanagementpractices(BMPs). BMPsusedtotreatrunoffmustbecapableofremoving80%oftheaverageannualpostdevelopmenttotalsuspendedsolids(TSS)loadbasedonexistingmonitoringreports.BMPsareconsideredtomeetthesecriteriaif:• Theyaredesignedinaccordancewithstandardsandspecificationsfromastateorlocalprogramthathasadoptedtheseperformancestandards.Or• Thereexistsinfieldperformancemonitoringdatademonstratingcompliancewiththecriteria.Datamustconformtoacceptedprotocol(e.g.,TechnologyAcceptanceReciprocityPartnership[TARP],WashingtonStateDepartmentofEcology)forBMPmonitoring
• Use alternative surfaces (e.g., vegetated roofs, pervious pavement, grid pavers) and nonstructural techniques(e.g.,raingardens,vegetatedswales,disconnectionofimperviousness,rainwaterrecycling)toreduceimperviousnessandpromoteinfiltrationandtherebyreducepollutantloadings• Usesustainabledesignstrategies(e.g.,low-impactdevelopment,environmentallysensitivedesign)tocreate integratednaturalandmechanicaltreatmentsystemssuchasconstructedwetlands,vegetatedfiltersandopenchannelstotreatstormwaterrunoff
Requirement:
PotentialTechnologies&Strategies:
LEEDSystemandLIDNewConstruction:WaterEfficiency(WE)Credit1
Tolimitoreliminatetheuseofpotablewaterorothernaturalsurfaceorsubsurfacewaterresourcesavailableonorneartheprojectsiteforlandscapeirrigation.
Requirement:
1.Reduceby50%(2points) Reducepotablewaterconsumptionforirrigationby50%fromacalculatedmidsummerbaselinecase.Reductionsmustbeattributedtoanycombinationofthefollowingitems:
•Plant species,density and microclimatefactor•Irrigationefficiency•Useofcaptured rainwater •Useofrecycledwastewater •Useofwatertreatedandconveyedbyapublicagencyspecificallyfornonpotableuses Groundwater seepage that is pumped away from the immediate vicinity of building slabs andfoundationsmaybeusedforlandscapeirrigationtomeettheintentofthiscredit.However,theprojectteammustdemonstratethatdoingsodoesnotaffectsitestormwatermanagementsystems
2.NoPotableWaterUseorIrrigation(4points)MeettherequirementsforOption1.And• Useonlycapturedrainwater,recycledwastewater,recycledgraywaterorwatertreatedandconveyedbyapublicagencyspecificallyfornonpotableusesforirrigation.Or
• Installlandscapingthatdoesnotrequirepermanentirrigationsystems.Temporaryirrigationsystems
usedforplantestablishmentareallowedonlyifremovedwithin1yearofinstallation.
PotentialTechnologies&Strategies:
• Performasoil/climateanalysistodetermineappropriateplantmaterialanddesignthelandscapewithnative.Or• Adaptedplantstoreduceoreliminateirrigationrequirements.Whereirrigationisrequired,usehigh-efficiencyequipmentand/orclimate-basedcontrollers.
LEEDSystemandLIDNeighborhoodDevelopment:GreenInfrastructure/Building(GIB)Credit8
To reduce pollution and hydrologic instability from stormwater, reduce flooding, promote aquiferrecharge,andimprovewaterqualitybyemulatingnaturalhydrologicconditions
Requirement:
Implementacomprehensivestormwatermanagementplanfortheprojectthatretainson-site,throughinfiltration, evapotranspiration, and/or reuse, the rainfall volumes listed in Table 1. Rainfall volume isbasedontheproject’sdevelopmentfootprint,anyotherareasthathavebeengradedsoastobeeffectivelyimpervious,andanypollutiongeneratingpervioussurfaces,suchaslandscaping,thatwillreceivetreatmentsoffertilizersorpesticides.
Thepercentilerainfallevent(Table1)isthetotalrainfallonagivendayintherecordthatisgreaterthanorequaltoXpercentofallrainfalleventsovera20-to40+-yearperiod.
Table1.pointsforretainingstormwateron-site
Projectsthatearnatleast2pointsunderthiscreditmayearn1additionalpointbymeetingoneofthefollowingsitecharacteristics:• Theprojectislocatedonapreviouslydevelopedsite(1point).• TheprojectislocatedonasitethatmeetsthedefinitionofbrownfieldinSLLCredit2,BrownfieldsRedevelopment(1point).• Theprojectisdesignedtobetransitreadybyachievingthefollowing(1point): Atleast2pointsunderNPDCredit1,WalkableStreets Atleast2pointsunderNPDCredit2,CompactDevelopment Atleast2pointsunderNPDCredit3,Mixed-UseNeighborhoodCenters
SelectBMPsfromtheWashingtonStateDepartmentofEcology’sStormwatermanagementManualforWesternWashington,VolumeV,RunoffTreatment(2005edition),orlocallyapprovedequivalent,whicheverismorestringent.IftheBMPsarecomparableinstringency,chooseBMPsthataremostappropriatetotheprojectsiteandregion.BMPsmustalsocomplywithallfederal,state,andlocalregulations.
Forstormwaterreusesystemsnotonacombinedstormwaterandsewersystem,thetotalwaterreusedforindoorusemustnotexceed90%oftheaverageannualrainfall.
StormwaterBMPs(exceptcisterns)mustbedesignedtodraindownwithin72hours.
LEEDSystemandLIDExistingBuildings:Operation&Maintenance(LEEDBO&M):SustainableSite(SS)Credit6
TolimitthedisruptionofnaturalhydrologybythebuildingandgroundsRequirement:
During theperformanceperiod, implementa stormwatermanagementplan that infiltrates, collects andreuses runoff or evapotranspirates runn off from at least 15% of the precipitation falling on the wholeproject siteboth foranaverageweatheryearand for the two-year,24-hourdesign storm. Implementanannual inspectionprogramof all stormwatermanagement facilities ro confirm continuedperformance.Maintain documentation of inspection, including identification of areas of erosion,maintenanceneeds,andrepairs.Performallroutinerequiredmaintenance,necessaryrepairsorstabilizationwithin60daysofinspection.
PotentialTechnologies&Strategies:
Collectandreusestormwaterfornon-portableusessuchaslandscapeirrigation,toiletandurinalflushingand custodial uses. During facility or site alterations or additions, specify the use alternative surfaces(e.g.,vegetatedroofs,perviouspavementorgridpavers)andnonstructuraltechniques(e.g.,raingardens,vegetatedswales,disconnectionofimperviousness,rainwaterrecycling)toimproveperviousness,therebyrestoring or maintaining natural stormwater flows. Incorporate stormwater management facilities intoroutinepreventiveandcorrectivemaintenanceprograms.
PotentialImprovementofLEED
• LEEDshouldbemorepregressiveonquantitativerequirement:
“Implementastormwatermanagementplanthatpreventsthepostdevelopmentpeakdischargerateandquantityfromexceedingthepredevelopmentpeakdischargerateandquantityforthe1-and2-year24-hourdesignstorms”-------LEEDNC:SSCredit6.1
• LEEDshouldcollaboratemoreintenselywiththewholerelateddomains:
E.g.,Landscapedesign,Energy-relateddevelopment,etc.
• LEEDshoulddevelopdeepervisioninresolvingstormwaterfromrootcausesandaregional perspective E.g.,Cumulativeeffectsofstormwater,Watersheddecaying,Faililnginfrastructure,etc.
• LEEDshouldextendmoreactivelyintothepublicareawithmoreinteractionwiththemunicipalpowerandpublicparticipation E.g.,Publicinfrastructureupgrading,Sweagepipesmaintenance,Publiceducation/publication,etc.
ComparisonwithotherSystems
LEED EarthCraft EPARegulationsUSGreenBuildingCouncil(USGBC)
GreaterAtlantaHomeBuildersAssociationandSouthface
EnergyInstitute
UnitedStatesEnvironmentalProtectionAgencyAgencies
Structure
NC/ND/Homes/CommercialInterior/
Homes/Schools/ExistingBuildings(Operation&Maintenance)/Core&
Shelldevelopment/Retail
House/LigthCommercial/Renovation/Multifamily/
Communities
ClearWaterAct/Section438ofEnergyIndependenceandSecurityAct,etc.
Weakness
StrengthHighrecognition
ComprehensivesystemPrecisedefinition,ProfoundvisionStrongenfrocement,WideRangeLocal and regional cooperation
InterdisciplinaryEffortEnergy-inclined
InterdisciplinaryEffortEnergy/ReuseProfoundvision
CommercialStrategy
StringencyLocal and regional cooperation
Definiterequirement
Comprehensivesystem
ApplicationofLEEDonRichmond,VAProblemsHinderingStormwaterManagement
ofRichmond:
• NegativeinfluenceoftheentireChesapeake
Baywatershed
• Outdateddrainagepipesanderosionofur-
banproperty
• Designersanddevelopersvision
ApplicationofLEED:
• MoreemphasisandcreditshouldbeplacedtosolvetheproblemofthepublicutilitiesE.g.,outdateddrainagepipes,dirtyanddisrepairedstreetsanddilapidatedlandscape• Preservingandrehabiliatingtheentirewatershed• Instructdevelopers,designersandengineerstoproceedfromthebigpicturetoresolvethedeeply-rootedstormwaterproblems