Post on 02-Aug-2018
EvaluationoftheLandfillOdorProblemattheSunshineCanyonLandfill
Preparedby:YazdaniConsulting
RaminYazdani,Ph.D.,P.E.1800BirchLaneDavis,CA95616(530)574‐1499
Preparedfor:SouthCoastAirQualityManagementDistrict
21865CopleyDriveDiamondBar,CA91765
August15,2015
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Table of Contents
PURPOSE.....................................................................................................................................................3
LANDFILLS..................................................................................................................................................4
SITEBACKGROUNDANDHISTORY....................................................................................................4
STUDIESCONDUCTEDATSCLTOMITIGATELANDFILLODOR...............................................6
METHODSFORESTIMATIONOFLANDFILLGASGENERATIONRATE...................................8
IMPACTOFBAROMETRICPRESSURECHANGEONLANDFILLMETHANEEMISSIONANDAUTOMATEDLANDFILLGASWELLADJUSTMENT....................................................................11
LANDFILLGASCOLLECTIONEFFICIENCYMEASUREMENTUSINGGASTRACERS..........15
BETTERLANDFILLGASCOLLECTIONSYSTEMDESIGNTOMITIGATEEMISSIONSANDAIRINTRUSIONINLANDFILL...........................................................................................................17
SATURATEDWASTECONDITIONANDGASCOLLECTIONEFFICIENCY..............................19
HYDROGENSULFIDEPRODUCTIONINLANDFILLSANDTHEUSEOFSOILASDAILYCOVER.......................................................................................................................................................20
CONTROLOFEMISSIONSATTHEACTIVEFILLINGAREA.......................................................21
IMPACTOFDAILYCOVERSOILUSEONLANDFILLGASTRANSPORTANDEMISSION..21
MEASUREMENTOFWHOLE‐LANDFILLGASEMISSIONS.........................................................24
SUMMARYOFRECOMMENDATIONS:.............................................................................................25
APPENDIXA............................................................................................................................................28
LIMITATIONS.........................................................................................................................................32
LISTOFREFERENCES..........................................................................................................................33
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YazdaniConsultingRaminYazdani,Ph.D.,P.E.
1800BirchLaneDavis,CA95618
Tel(530)574‐1499Email:ryazdani@sbcglobal.net
August15,2015Mr.NicholasA.SanchezSeniorDeputyDistrictCounselSouthCoastAirQualityManagementDistrict21865CopleyDriveDiamondBar,CA91765Subject: EvaluationofLandfillOdorProblemattheSunshineCanyon
LandfillDearMr.Sanchez:Atyourrequest,YazdaniConsultinghasreviewedtheavailabledataforSunshineCanyonLandfill(SCL)andhasidentifiedpotentialimprovementsinthedesignandoperationofthelandfillgas(LFG)collectionsystemtoreducegasemissionsandodors.Thepurposeofthispreliminaryevaluationwastoprovideasummaryofknownsiteconditions,andproposefurtherinvestigationandpotentialsolutionstobettermanageLFGcollectionandcontrolodornuisance.Theresultsareprovidedbelow.
Purpose YazdaniConsultingwasretainedbySouthCoastAirQualityManagementDistrict(SCAQMD)toprovideconsultingservicestoSCAQMDandtoassistHydroGeoChem,Inc.(HGC)intheplanning,testingandevaluationoftheSCLgascollectionsystemusingbaro‐pneumatictestingandcomputermodeling.Inaddition,provideideasforfurtherinvestigationthatwouldyieldbettermanagementofthelandfillgascollectionsystemandcontrollandfillodornuisance.
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Landfills Whensolidwastecontainingorganicmaterialsisdisposedinlandfills,thewastedecomposesanaerobically,resultingingenerationoflandfillgasconsistingmainlyofCH4(50%)andCO2(50%).Thegasgenerationdependsontheamountandageofwasteinthelandfill,thewastecomposition,nutrients,presenceofinhibitorycompounds,andthelandfillconditionssuchastemperature,wastemoisture,wastepH,wastecompaction,andlandfillcoverdesign.Thelandfillgasbuildsuppressureinsidethelandfillandthepressure,togetherwithdiffusion,causesgasescapefromthelandfill.AsillustratedinFigure1,thefugitiveemissionandodorfromalandfilloccursthroughmanydifferentescaperoutesandmeasuringtheindividualortotalemissionratefromtheseroutesischallenging.Thegeneratedgascanberecoveredbyengineeredgascollectionandremovalsystemsandutilizedforenergyproduction,whichreducestheoverallemissions.TheCH4emissionsthroughthesoilcoverandcrackscanbemitigatedthroughtheuseofbiocoversystemwheremethaneisoxidized.However,reliablemeasurementsforquantificationofLFGcollectionefficiencyandmethaneoxidationinbiocoversarenecessary.
Figure1‐Methaneproduction,transport,andemissionfromalandfill.1
Site Background and History SunshineCanyonLandfill(ClassIIIlandfill)operatesunderSolidWasteFacilityPermit19‐AA‐2000issuedbyCalRecyclelocatedinSylmar,California.ThesiteisownedandoperatedbyBrowningFerrisIndustriesofCalifornia,Inc./RepublicServices,Inc.The“CountyLandfill”DisposalPhasesIthroughVarelocatednorthoftheCity‐Countyboundary,andwereconstructedwithacompositelinerandleachatecollectionandremovalsystem.The“CityLandfill”includesUnit1andUnit2wastedisposalareasthataresouthoftheCity‐Countyboundary.CityLandfillUnit1isaclosed,unlinedClassIIIMSWdisposalunitthatoperatedbetween1958and
Gas well
CHrecovered
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Anaerobic methane production:methanogens in waste
Lateral migration
CO2
CH4
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CH emission throughcover and cracks4
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1993.CityLandfillUnit2iscurrentlyactive,ClassIIIMSWdisposalunitthatwasconstructedwithacompositelinersystemandislocatedgenerallybetweenCityLandfillUnit1andtheCountydisposalphases.CellAofCityLandfillUnit2beganoperationsduringthethirdquarterof2005,withsubsequentdisposaloperationsexpandingintoCellsCC‐1andCC‐2.RefuseiscurrentlybeingdisposedofinCellCC‐3A(SeeAppendixA,FigureA1‐SCLProposedPhasingPlan).Themaximumweeklytonnagereceivedatthefacilityis66,000tonsofmunicipalsolidwaste(MSW)fordisposaland6,600tonsofmaterialreceivedforbeneficialreuseandrecycling,whichtogethertotal72,600tonsperweekforallmaterial.Currentlythelandfillreceives8,300tonsofMSWperday.Thepermittedmaximumelevationofthewasteis1,904ft.(MSL)onportionswithinthe“CountyLandfill”boundaryand2,004ft.(MSL)onportionswithinthe“CityLandfill”.Thetotalpermittedareaforwastedisposalis363acreswithdesigncapacityof140,900,000cubicyardsofMSW.Thesiteisestimatedtocloseby2037.Since2009,themembersofcommunitiessurroundingtheSunshineCanyonLandfill(SCL)havereportedsmellingodorstoSCAQMDandSCL(SeeFigure2).Inresponsetothecomplaints,SCAQMDstaffsoughtanOrderforAbatementfromitsautonomousHearingBoard.TheHearingBoardissuedanOrderforAbatementthatrequiresanumberofactivitiesdesignedtoreducepotentialodorsfromthelandfill,suchasinstallationofadditionalgaswellsandflares;limitinglandfillingundercertainwindconditionsatcertaintimesofday;implementingnewrestrictionsattheworkingface;enhancingodorpatrols;reroutingtransfertrucksonMondaymornings;andreplantinglostvegetationthatmayhelpwiththedispersionofodors.TodateRepublicServiceshasengagedinavarietyofstudiesaimedatbetterunderstandingthesourcesofpotentialodorsfromtheSCL,thepossibletransportofodorsfromSCLtothecommunity,andpotentialodor‐reductionmeasures.RepublicServiceshasimplementednumerousodorcontrolmeasuresandhashiredconsultantstoevaluatetheimmediateandfutureneedsofLFGcollectionanddisposalsystemstoaccommodatethecaptureanddestructionofallgasexpectedtobegeneratedatthelandfillusingverticallandfillgaswells,horizontalcollectors,linercollectors,trenchcollectors,andflares.InMarch2010,theSCAQMDissuedastipulatedorderforAbatementfollowedbythreestipulatedAmendedordersforAbatementthatimposedaseriesofconditionsincludingmakingenhancementstotheLFGcollectionsystemtoaddressodornuisance.Inaddition,theCountyofLosAngeles,PublicWorksDepartmentrequiredcorrectivemeasuresbeimplementedbyRepublicServicestoreduceodors.RepublicServiceswasrequiredtocoverdisposedsolidwastewithaminimumof9‐inchesofcompactedsoilattheendofeachoperatingdayinlieuofusingtarporotheralternativedailycover.RepublicServiceswasalsorequiredtodiscontinueremovalofthedailycoveratthebeginningofthenextoperatingday.Inspiteoftheseoperationalchangesthathavetakenplaceduringthepastfouryears,odorcomplaintscontinuebutthenumberofcomplaintshasdecreaserecently.DataonthenumberofcomplaintsreportedtoSCAQMDbetween1995and2015isshowninFigure2.
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InOctober22,2014,theCountyofLosAnglesPublicWorksDepartmentrequiredRepublicServicestoimplementadditionalcorrectivemeasurestomitigatetheodornuisanceresultingfromactivitiesrelatedtotheoperationoftheSCL.TheLFGmanagementrequirementswereasfollows:a)newlycompletedcellsshallhavethreeverticalgasextractionwellsperacreandhorizontalcollectorsareeveryotherlift.Forcellsthatwillbeinactiveformorethantwodayshorizontalgascollectorsmustbeinstalledwithinthetoplift;b)Ataminimumforeachexistingandfuturedevelopmentcellcalculatethein‐placedensityoffillmaterialtakingintoaccountthedailysoilcover,andcalculatetheradiusofinfluenceaswellasspacingforverticalgasextractionwellsandhorizontalgascollectorsbasedonthatdensity.Areaswithdifferentsitecharacteristicsmayrequireseparatecalculationsofin‐placedensities.ThesecalculationsandwellspacingmustbesubmittedtoPublicWorksforapprovalwithcopiestoSCAQMDandSCLLocalEnforcementAgency(LEA).
Figure2‐TotalnumberofcomplaintsreportedtotheSCAQMDbetween1995to2015(FigureprovidebySCAQMD).
Studies Conducted at SCL to Mitigate Landfill Odor Addressingvariousoperationsanddesignissuescanreducelandfillodorinthesurroundingareaofalandfill(Figure3).Theseissuesare:a)reducingtheworking
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faceofthelandfillandapplicationofdailycovermaterial;b)timelyapplicationoffinalcoverandvegetationlayer;c)properlysizedLFGcollectionandcontrolsystem;d)odor‐neutralizingchemicalsprayedalongtheborder;e)propermaintenanceofleachateandLFGcontrolequipmentcomponents;f)surfacewatermanagementandpropergradingofthelandfillsurfacetoreducewaterinfiltration;g)usingthegasasafueltoreduceodorsandprovideelectricity.
Figure3‐Typicallandfillwithvarioussystemstocontrolodor.2StudiesthathavebeenconductedatSCLtobetteridentifythecauseandtobettermanageodorattheSCLlandfillarelistedbelow.Someoftherecommendationsidentifiedinthesestudieshavealreadybeenimplemented.In2011astudywasconductedbyENVIRONInternationalCorporation3toevaluatetheimpactoflandfillworkingfacesizeandrateofwastedepositedonodor.Basedonthedatacollecteditappearedthatodorsourcestrengthattheworkingfacedidnotcorrelatewithworkingfacesize.Also,thechemicalmeasurementsaswellasolfactoryobservationsdidnotindicateanyapparenttrendswhencomparedtoworkingfacesizeandodorcomplainsreceivedfromthehotlines.In2011TetraTechBAS(BAS)4evaluatedtheexistinglandfillgascollectionandcontrolsystemandrecommendedchangestoincreasethecurrentlandfillgascollectionefficiency.BASusedtheOctober4,2010LFGgenerationanalysispreparedbyCornerstoneEnvironmentalGroup,LLCastheprimaryreferenceforanindependentanalysis.Cornerstone’sreportreferencedseveralwastecompositionstudiesperformedfortheSCL.InFebruary2015,TetraTech,Inc.andEcoTelesisInternational5performedamorerecentwastecharacterizationstudyperformedtodevelopbetterparametersforthelandfillgasmodelsusedattheSCL.Accordingto
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thisstudythetotalreadilydegradablewetfractionoforganicwaste(foodwaste)wasdeterminedtobebeween23%to30%.In2011,landfillgascollectionimprovementrecommendationsbyBASwere:a)installationofadditional70verticalgaswellsintheareaswiththemostsurfaceemissions;b)installationofatemporaryflarewitha3,000SCFMcapacity;c)replacementofflare#8withalargercapacityflare;d)evaluationforimprovementofflarestation#1and#3;e)replacementoftheundersizedgascollectionandcontrolsystempiping.ManyoftheserecommendationshavealreadybeenimplementedattheSCL.In2012,awhitepaperwaspreparedbyBlueRidgeServices6toevaluateanddeterminethemosteffectivemeanstopreventoff‐siteodorfromtheactivefaceofthelandfill.BlueRidgeServicesevaluatedtheeffectivenessoftherequirednine(9)inchesofdailysoilcoverasamitigationmeasureforreductionofoff‐siteodorsascomparedtotheregulatorystandardsix(6)inchesof`soil.Othersiteconditionsthathavehistoricallycontributedtotheoff‐siteodorproblemwerealsoevaluated.Therecommendationofthisstudywastodiscontinueplacementofnine(9)inchesofdailycoversoilandinsteaduseAlternativeDailyCover(ADC).Additionally,itwaspointedoutthattheuseofnine(9)inchesofdailycoversoilcouldimpedetheverticalmovementofleachateandlandfillgasandcauselateralmigration.SeeAppendixA,FigureA2,fortheboundaryofthenine(9)inchesofdailysoilcoverandthelocationofverticalgaswellswithdedicatedpumpsfordewateringgaswells.
Methods for Estimation of Landfill Gas Generation Rate ThereareseveralmethodstoestimateLFGgenerationrate:a)afirst‐orderkineticgasgenerationmodelsuchastheLandfillGasEmissionModel(LandGEM)(USEPA20057);b)combinationofpneumaticwelltestdatawithassumptionsaboutwellrecoverytoestimateLFGgeneration(EMCON19808);c)andbiokineticmodelsdescribingstagesofwastedecomposition(El‐Fadeletal.19969).ThesemethodshavesignificantlimitationswhenestimatingtheactualLFGgeneration.ThedefaultCH4generationpotential,L0,andfirst‐orderwastedecayrate,k,recommendedinLandGEMmodelaredependentonsiteconditions(ScharffandJacobs200610)andevenwhensitespecificL0areusederrorscansignificantlyaffectestimatesofk(Tolaymatetal.201011).Additionally,estimatesrequireassumptionsabouttheLFGcollectionefficiency,whicharealsounknown.Inanotherrecentstudy12,theobservedmethanecollectiondatafrom11U.S.landfillsandestimatesofgascollectionefficienciesdevelopedfromsite‐specificgaswellinstallationdatawereincludedinareformulatedLandGEMequation.TheresultsdemonstratedthatthecurrentLandGEMmodel(AP‐42)defaultdecayrateusedbyindustryistoolow.Thisissignificantbecauseahigherdecayratewillresultinpredictionsofmoremethanegenerationintheearlyyearsafterwasteburialwhengascollectionefficienciestendtobelower.Thushigherdecayrateswillresult
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inhigherestimatesofuncollectedmethane.ThisresearchalsosuggeststhatitismisleadingtorefertoL0asthemethaneproductionpotentialbecausethevalueofL0inLandGEMincludesunmodeledparametersthatinfluencemethanegeneration.Furtherworkisrequiredtoidentifythecontrollingunmodeledparameters,explorereformulationsofLandGEMthatmightincludeaslowandrapidlydecomposingwastefraction,quantifyuncertainty,andexpandobservationaldatasets.Thebaro‐pneumaticmethod(Bentleyetal.200313)usedbyHGCinthemostrecentstudyattheSCLquantifiedLFGgenerationratesandestimatedthefieldgaspermeabilitywithinthelandfillusingsimultaneousmeasurementofgaspressureatthesurfaceandatvariouslandfilldepths.Themathematicalanalysesofpressurechangesintherefuseinresponsetovariationinatmosphericpressure,LFGgeneration,andpumpageatLFGextractionwellwereusedtomaketheestimate.Thebaro‐pneumaticmethodusessite‐specificdatathatreduceuncertaintiesinestimatedofLFGgenerationrates.ThismethoddoesnotassumethattheLFGgenerationrateisequaltotheflowrateofagasextractionwellwithinitszoneofinfluence,anassumptionthatistechnicallyflawed(Walter200314)andthereforethebaro‐pneumaticmethodisabettermethodtoquantifyLFGgenerationrates.
Photo1‐Shallowanddeepvapormonitoringwellswithpressuretransducersinstalled.In2014,SCAQMDhiredHydroGeoChem,Inc.(HGC)15toperformfieldtestsandcollectatmosphericandsubsurfacepressuredatawithinthelandfillandanalyzethecollecteddatabothqualitativelyandquantitativelytomakerecommendationforpotentialsolutionstocontrolodorfromthelandfill.Threelocationswereselectedforthisfieldstudy.TwolocationswereselectedinthenewerportionofthelandfillnearcollectorwellCGW740S/DandCGW575andthethirdlocationintheolderportionoftheCitylandfillnearthecollectorwellGW7024(SeeAppendixA,FigureA3).Afterthewellmonitoringinstallation,HGCinstalledaseriesofpressure
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transducersformonitoringpressureswithinthelandfillatthesethreelocations(Photo1).AtlocationCGW740S/Dresultsdemonstratethatcovermaterial(approximately1.5feetthickatthislocation)providesonlyaslightbarriertopneumaticcommunicationbetweentheatmosphereandthesubsurface,consistentwithitsthinnessandamoderatelyhighverticalpermeability.Theresultsalsosuggestthattheverticalpermeabilityofatleasttheshallowestrefuse(between1.5feetand8feetindepth)isrelativelyhigh.Theapparentpoorcommunicationofdeeprefusewiththeatmospheresuggeststhatthedeeprefusehasalowgaspermeabilityorthatpartialpneumaticbarriersexistintherefuseatdepthsgreaterthanapproximately35feetbls,possiblytheresultoflayershavinghighwatercontentsandlowgasporosity.Overall,theLFGcollectionsystemappearstobeeffectiveatthislocationexceptinthedeeprefusewherepressuresaregreaterthanatmosphericandatdistancesgreaterthan75feetfromCGW740S/DwhereLFGcontrolsysteminducedvacuumswereslight.AtlocationCGW575,thecovermaterialisapproximately6feetthickandprovidesabarriertopneumaticcommunicationbetweentheatmosphereandthesubsurface.Theapparentpoorcommunicationofdeeperrefuse(>95ft.bls)withtheatmospheresuggeststhatatleastpartialpneumaticbarriersexistintherefuse.AtlocationGW7024,thecovermaterialthicknessisapproximately10feetthickandthedatasuggestthatcoversoilhashighereffectivegaspermeabilitythancoveratCGW575.Theresultsaboveindicatethatthecoversoilpermeabilitymaybetoohighorsoilmaynotbecompactedenough,allowinggasemission.Comparingthiswiththepublishedsoilsurvey16fortheSCL(Figure4andFigure5),themajorityofthesoilsattheSCLareratedtohaveamoderatelyhigh‐saturatedhydraulicconductivity.Thereisnotaclearproportionalitybetweenhigh‐saturatedhydraulicconductivityandporosity.However,typicallysandysoilwithhighporositywillhaveahighhydraulicconductivity(moreopenareasforflowofwaterorgas),butthisrelationshipismorecomplicatedinsoilswithclay.Werecommendthecollectionofin‐tactcoresamplesofcoversoilatvariouslocationsattheSCLforlaboratorytesting.ThesesampleswillbesenttotheUniversityofDelawarelaboratorieswheredensity,totalporosityandgastransportpropertieswillbemeasured.Whiletheinitialwatercontentofthesampleswillberecorded,theeffectofmoistureongastransportwillbeevaluatedbyvaryingthewatercontentsystematicallyineachsampleinthelaboratory.Wecanprovideadetailproposalforfurtherstudyatalaterdate.
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Figure4‐MapofstandardclassesofsoilatSCL.16
Figure5‐SaturatedhydraulicconductivityofsoilsatSCL.16
Impact of Barometric Pressure Change on Landfill Methane Emission and Automated Landfill Gas Well Adjustment Inanumberofstudiestheinfluencesofatmosphericpressureonlandfillmethaneemissionshavebeenevaluated.ThediurnalmeasurementduringadropinbarometricpressureshowthatLFGfluxescanchangedramaticallywithinavery
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shorttime(Czpieletal.,200317;Gianietal.,200218;Christophersen,etal.,200119;Xuetal.,201420).Forexample,inonestudybyCzepiel,etal.200321conductedattheNashua,NewHampshiremunicipallandfill,withanactiveverticalandhorizontalgascollectionsystem,foundsurfacemethanefluxesincreased300%duetodecreasesinbarometricpressureof10millibars,whichoccurredduringpassageoflowpressureweatherfrontsoverananaerobiclandfill(Figure6).Inanotherlandfillstudywithpassivegascollectionsystema35‐foldvariationinday‐to‐daymethaneemissionswasobservedduetochangesinbarometricpressure(Figure6).Risingbarometricpressuresuppressedtheemission,whilefallingbarometricpressureenhancedtheemission,aphenomenoncalledbarometricpumping(Xuetal.,201420).Generallyspeaking,highpressure(usuallydryair)isassociatedwithcalm,sunnyweatherandlowpressure(generallymoistair)occursoncloudy,rainydays.
Figure6‐Resultsfromtwostudiesshowingincreaseinmethaneemissionsoverashorttimeasbarometricpressuredrops17,20.AsdemonstratedinFigure7andFigure8,theatmosphericpressureattheSCLchangesonadailyorevenhourlybasis,aswellasseasonally.Thisisduetonormaldayandnightcycleofsolarradiation,andalsoduetolocalweatherpatterns.SCAQMDRule1150.1requiresquarterlylandfillemissionsmonitoringbywalkingthesurfaceofthelandfillandscanningformethaneemissions(atthissitemonthlyemissionsmonitoringisperformed).Typicallysurfaceemissionmonitoringisnotperformedduringfallingbarometricpressure(badweathersuchaswindgreaterthan5mphand/orrainyweather)whenthesurfaceemissionscouldbehigher.Landfillsurfacescanningisnormallyperformedduringthedaywhentheweatheriscalmandthebarometricpressureishigh.Thiscouldunderestimatetheactualaveragedailyemissionmeasuredbysurfacescanningmethod.Ifthebarometricpressuredropsduringthenight,emissionfluxandodorfromthelandfillincrease.CurrentairemissionregulationsignorethebarometricpressureimpactsandassumethatsurfaceemissionisconstantunderhighorlowatmosphericpressureinlandfillswithactiveorpassiveLFGcollectionsystem.Inordertopreventexcessemissionandodorfromthelandfilleachwellheadmustbeundercontinuousmonitoringandautomaticallyadjustedasthebarometricpressurechanges.Thisisnottypicallydoneandisnotevenrequiredbyregulations;however,thistypeof
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landfillgasoperationmayreduceemissionsandthereforeodorfromthelandfill.Suchasystemwasdesigned,testedandsuccessfullyoperatedattheYoloCountyCentrallandfillaspartofaresearchprojectfortheCaliforniaEnergyCommission22.AcommercialversionofsuchsystemhasrecentlybeendevelopedbyLociControls23andinthesummerof2014wastestedattheCrapoHillLandfillinDartmouth,Massachusetts.UsingautomationtocontroleachgaswellheadincreasedthepoweroutputfromtheLFGtoenergyfacilityby26%atthislandfillsite,andthereforereducedtheoveralllandfillgassurfaceemissions.Photos2and3showthetypicalcontrolsoftwarescreenusedforautomaticadjustmentofthegaswellheadandthewellheadconstructionatthelandfill,respectively.WerecommendedthatsuchasystembetestedattheSCLonamainheaderlinewhereseriesofLFGwellsareconnectedtogetherandononeLFGwell.Automaticadjustmentofindividualgaswellsisidealbutautomaticadjustingofthemainheaderlinewithseriesofgaswellsconnectedtogethercouldalsoimprovefugitivegasemissions.Gascollectionsystemshouldbetestedundervariousoperatingparameterssuchaswellheadsuctionandgascompositiontodeterminetheeffectivenessofsystemandreductionoffugitivegasemissionsandairintrusion.Wecanprovideadetailproposalforfurtherstudyatalaterdate.
Figure7‐BarometricpressureatSunshineCanyonLandfillduringpneumatictest(datafromHGCpneumaticfieldtest‐June27‐July1,2015).
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Photo3‐LociControlsWellWatchermonitoring&controlsystemusedtoautomaticallyadjustandmonitoreachlandfillgaswell.
Landfill Gas Collection Efficiency Measurement Using Gas Tracers WhendesigningaLFGcollectionsystem,anassessmentoftheregionofinfluence(ROI)ofeachwellinrequired.AsimplewaytoassesstheROIofapumpingwellistomeasurethegaspressuredistributionintherefusewiththewellonandoff.Ifthereisameasurabledifferenceingaspressureatanysamplingpointbetweentheon/offconditions,thenthispointisimpactedbythewell.TheROIisaffectedbytheLFGgenerationrate,whichcanvaryinspaceandtime;wastecompactionandmoisturecontent;theextractionrateatindividualwells;thelocationsofwellsinthelandfill;andthedegreetowhichgascanpermeatethelandfillboundaries.UnderstandingwhereLFGcollectionis“good”andwhereitis“poor”isthefirststeptodevelopingimproveddesignsforgascollectionsystems.CurrentlyweareonlyawareofonestudywheredirectmeasurementsLFGcollectionefficiencywasmadeusinganin‐situgastracermethod(Yazdanietal.,201524).ThegastracermethodwasusedtoquantifygascollectionefficienciesatvariouspointsinatestlandfillwellandresultswerecomparedwiththeROIasdeterminedfrompressuremeasurements.Whileanassessmentofawell’sROImightresultinspecifiedsteady‐statesuctionsappliedatwell‐headstoachieveoptimalcollectionefficiency,transientLFGflowresultsfrombarometricpressurevariationscansignificantlyimpactcollectionefficiency.Asdiscussedearlier,publishedliteratureindicatesthatbarometricpressurechangesresultinundesired
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“pulses”ofLFGemissionstotheatmospheresimilartowhathasbeenobservedattheSCLduringearlymorningandlateafternoonasindicatedbytheBlueRidgeServices6reportandotherstudies(KjeldsenandFischer199525;BorjessonandSvensson199726;Christophersen,Kjeldsenetal.200127;Czepiel,Shorteretal.200328).Inaddition,over‐pressureLFGbuildingwithinisolatedareasofthelandfillcouldalsocausereleaseofLFG.Thus,aLFGcollectionsystemthatismanuallyadjustedonaweeklyormonthlybasiswithoutconsiderationofatmosphericpressurechangesorinternalpressurewithinthelandfillmayresultinappreciablefugitivemethaneemissionsaswellasairintrusion.Imhoffetal.,201224performedcomputersimulationsandhaveconductedlarge‐scalefieldteststhatsupportsthisobservation.AsillustratedinFigure9(a),twovariationsinatmosphericpressureareshown:amoderatecase,where24‐houraveragebarometricpressuredatafromSacramento,Californiacollectedforaone‐monthperiodwereused;andastrongcase,wherevariationsinatmosphericpressuresmeasuredattheSkellingstedLandfill,Denmark(Poulsen,Christophersenetal.200329)wereselected.TheresultingLFGemissionspredictedfromthisLFGmodel(Jung,Imhoffetal.200930)areshowninFigure9(b).Fortwocases:onewithapermeablelayerinstallednearthelandfillsurfacetoenhanceLFGcaptureandonewithout.Inbothcases,thegascollectionwellwasoperatingsuchthataconstantmassfluxofLFGwasextractedfromthelandfill.Whiletheexistenceofanear‐surfacepermeablelayerdecreasedbaselinemethaneemissionsfrom22to15%ofthemethanegeneratedinthelandfill,barometricpressurechangesstillresultedinemissionspikes.Itisimportanttonotethatthesesimulationshadno“cracks”inthelandfillcoverandthesoiltypewasnothighlypermeable:crackingandpermeablecoversoilwouldallowsignificantlygreaterfugitiveemissionsinresponsetobarometricchanges,witheffectsapproachingthosecitedinCzepiel’sstudy(Czepieletal.,200328).Assuggestedearlier,werecommendthatanautomatedwellheadadjustmentbeusedtomitigatetheinfluenceofatmosphericpressurechangesontheoperationofLFGcollectionsystemsandemissions.Thistypeofoperationwillresultinreducedemissions,increasedcollectionefficiency,andthecostsassociatedwithsuchasystemmaybeoffsetbytheincreasedrevenuepotentialfromtheadditionalLFGcollectedandenergyproducedattheexistingLFGtoenergyfacility.Werecommendthatthein‐situgastracermethoddevelopedbyYazdanietal.,201524beusedtodeterminetheverticalgaswellcollectionefficiencyandtoassessalternativegascollectionstrategiesandlandfillcoversystem(intermediateandfinalcover)tomitigatetheeffectsofbarometricpressurechangesandvariouscoversystemdesignsusedtocontrolLFGemissions.
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Figure9‐Variationsinmethaneemissionsassociatedwithatmosphericpressurechangesovera24‐hourperiod(Jung,Imhoffetal.200930).Resultsareshownforalandfillwithorwithoutahorizontalpermeablelayerinstalledatthetopofthelandfill.(a)Variationsinatmosphericpressure;(b)variationsinmethaneemissions,expressedas%oftotalmethanegeneratedinrefuse.
Better Landfill Gas Collection System Design to Mitigate Emissions and Air Intrusion in Landfill TypicallyvacuumisappliedtoLFGcollectionwellstopullgasoutofthewasteinlandfillviaverticalextractionwellsorhorizontalextractiontrenches.Figure10(a)illustratesthedirectionandmagnitudeoftheexpectedgasflowswitharrowsdrawn.Pumpingoftheverticalgascollectionwellsmaycauseunequalmethaneemissionsandairintrusionatthelandfillsurface.ToaddressthisproblemanalternativeLFGcollectionsystemdesignisproposedfortheSCLasshowninFigure10(b)(Augensteinetal.,U.S.PatentNo.7,198,433(2007)31,Jung,etal.201132).Inthisnewlandfillgascollectionsystemdesign,ahigh‐permeabilitylayerisinstallednearthelandfillsurfaceandLFGiscollectedatdeeppumpingwells(notfromthehigh‐permeablelayernearthesurface).Thisenablesessentiallyuniformpressureacrosstheentiretyoftheconductiveorpermeablelayer,andcanenableauniformverticalpressuregradientthroughthesurfacelayersofthelandfillandgreatlyreduceirregularitiesinverticalgasflowatthelandfillsurface.Inotherwords,itwillgreatlyreducetheairentrainmentnearverticalwells,andfugitiveemissionfarfromverticalwells,asshowninFigure11.Theexpectationisbetterefficiencyofgascollectionbecauseahighpermeabilitylayerequalizesdifferencesingaspressurenearthelandfillsurfaceresultingin:1)reducedmethaneemissionsthroughcovermaterialsand;2)moreuniformflowofLFGthroughlandfillcovers;and3)reductionintheextentofairintrusion.
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Figure10‐Typicalcross‐sectionofgascollectionsystem:(a)conventionalverticallandfillgascollectionwell;(b)landfillgascollectionwellwithpermeablelayer.
Figure11‐Oxygenprofiles(%bymass)forconventionalverticallandfillgascollectionwell(left)andlandfillgascollectionwellwithpermeablelayer(right).Thistypeofdesignisalsoapplicablewhereforareaswithintermediatecoverandwastehasnotreachedthefinalelevationandadditionalwastewillbeplacedontopofexistingwastelift(Figure12).Permeablelayercanbeconstructedfromwastematerialthatisthreetofiveordersofmagnitudemorepermeablethanthesurroundingwastesuchasshreddedtires(usedonlyinareaswherewasteoxidizationisnotaconcern),gravel,andC&Dwaste.However,theintermediatecoversoilmaterialmustbelesspermeablethanthewastebelow.Thisdesignwillalsominimizeatmosphericairintrusionintolandfillgascollectionsystem,aproblemthatiscurrentlyseenintheSCLgassystem.Figure13showslandfillgasbalanceandoxygendataforalloftheverticalgaswells(notincludingCity‐Southarea)attheSCL(between2/4/2014to7/24/2015)forthepasttwoyears(12,487recordedverticalgaswellheadcompositiondatacollected).Duringthistime,368verticalgaswellsoutof410(89.8%oftheverticalgaswells)hadLFGbalancecontent(nitrogengas)equaltoorgreaterthanof20%(v/v),and95verticalgaswellsoutof410(23.2%oftheverticalgaswells)hadoxygencontentequaltoorgreaterthan5%(v/v).Thisindicatesthatmanyofthelandfillgaswellsarepullingairintothelandfill.Thiscreatesanoxidizingenvironmentinthelandfillthatleadstoconsumptionofmethanebyoxidationandcouldincreasetheriskoflandfillfire.
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WealsorecommendthatgassamplesfromthemainLFGcollectionsystemintheseareasbetestedforcarbonmonoxide(CO)levelsusinglaboratoryinstrument(gaschromatography)andnotmeasuredusingfieldinstrumentbecauseofinterferencewithothergasespresent.WealsorecommendtheproposedpermeablelayerLFGcollectionsystemdesignbetestedinasectionofthelandfill(intermediateorfinalfillarea)todeterminehowitmightbeimplementedtoreducegasemissionsattheSCL.Furtherassistanceinthedesignandtestingofsuchsystemcanbeprovided.Wecanprovideadetailproposalforfurtherstudyatalaterdate.
Figure12‐Landfillgascollectionwellwithpermeablelayerinstalledaswastefillingadvances.
Figure13‐SCLverticallandfillgaswelldatabetween2/4/2014to7/24/2015.
Saturated Waste Condition and Gas Collection Efficiency Wastethatissaturatedwithwatercangreatlyreducegaspermeability(Jainetal.,200533;Reinhartetal.,200234).Liquidmovementandchangeinwatersaturationmayalsobeaffectedbyrefuseheterogeneity(McCreanorandReinhart,200035).InalandfillsimulationstudybyJung,etal.,201132themeangaspermeabilityofwaste
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wasreducedbyafactoroffivewhileallotherparametersremainedthesame.Modelingresultsshowedthatwithoutthenear‐surfacepermeablelayertheconventionallandfillgasdesignhademissionsthatwere25%ofthetotalCH4generated.ThisindicatesthatconventionalLFGcollectionsystemsarenotefficientwheregaspermeabilitiesarereducedbecauseofelevatedmoistureconditions(Jainetal.,200533),conditionsthatappeartoexistinthelowerlayersofwasteattheSCL.Afterinstallationofdewateringwellsandtrenches,thenear‐surfacepermeablelayerdesignextendsthezoneofinfluenceofthepumpingwellandcausesamoreuniformverticalLFGflowabovethepermeablelayerandresultsinnearconstantcollectionefficienciesofbiogasregardlessofvariationsinheterogeneouslandfillconditions,includingvariationsingaspermeability(Jungetal.,201132).Werecommendthatdewateringtrenchesbeinstalledandthenewlandfillgascollectiondesignbetestedinasectionofthelandfillwithsaturatedconditionwithintermediatecovertodeterminehowitmaybeimplementedtoreducegasemissionsandimprovegascollectionefficiency.Furtherassistanceinthedesignandtestingofsuchsystemcanbeprovidedatalaterdate.Wecanprovideadetailproposalforfurtherstudy.
Hydrogen Sulfide Production in Landfills and the Use of Soil as Daily Cover Inlandfillenvironmentswherethereisanabsenceofoxygen(anaerobiccondition),microbesdegradeorganicwasteandproducecarbondioxide(CO2)andmethane(CH4),typicallyproducedinequalquantities(Eq.1).Whensulfurispresent,itisconvertedbyanaerobicbacteriatoH2S.Typicallysulfurispresentintheformofsulfate(SO4)butalsointheformofelementalsulfur(S)andsulfite(SO3).
Organicmatter(e.g.municipalwaste)+H2OCO2+CH4 Eq.(1)
Organicmatter(e.g.municipalwaste)+SO4+H2OH2S+CO2Eq.(2)
InorderforH2Stobeproducedinlandfillenvironment,asshowninEq.2above,twoingredientsareneeded,asourceoforganicmatterandsourceofsulfur(S).Organicmatterispresentintheformofmunicipalorcommercialwaste,biosolidsorleachateinliquidform.Thesulfur(S)canbepresentinconstructionanddemolition(C&D)waste(wallboard),thewallboardfinesfromamaterialrecoverfacility(MRF)thatprocessesC&Dwaste,flyashorotherindustrialwastecontainingsulfur.Also,sulfurcouldbepresentinthesoilusedasdailycoveratthelandfillsite.In2011,soilsamplesfromseveralsoilstockpilesattheSCLweretestedforvariouschemicalproperties.LaboratoryresultswerereportedinthegeologicalandgeotechnicalinvestigationreportpreparedbyAMEC,201136.BasedonthetestresultsbyAMECtheaveragesulfatecontentofsoilusedasdailycoverwas1,424mg/kg.Eachyearabout700,000to1,000,000cubicyardsofsoilisusedasdailyandintermediatecoversoilattheSCL.Calculationbasedontheaveragesulfatecontentofthecoversoilindicatesthataround1,500to2,100tonsofsulfateisaddedtothelandfillannually.Thishasthepotentialof
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producingover500to750tonsofH2S.Theuseofdailyandintermediatecoversoilwithhighlevelsofsulfatecouldincreasethepotentialforodors.Werecommendthatsamplesofthesoilusedfordailyandintermediatecoverbetestedforsulfurcontent.Samplesshouldalsobetestedforbiochemicalsulfurpotential(BSP)inananaerobicenvironmenttodeterminethepotentialofsoilproducingH2S.TheNorthCarolinaStateUniversitylaboratoryistheonlyoneweareawareofthatisqualifiedtoperformBSPtestsonsoilsamples.AproposalcanbeprovidedforlaboratorytestingofsoiltodeterminethesulfurcontentandtheBSP.
Control of Emissions at the Active Filling Area Inadditiontotherecommendationsmadeforalternativedailycover(ADC)tocontrolemissionsattheactivefillingareabyHGC15,otherADCmaterialsuchascompost37andshreddedgreenwaste38haveshowntobeaneffectivemeansofcontrollingLFGemissionsandshouldbeconsideredforfurthertestingattheSCLinsteadofnine(9)inchesofcoversoil.TheuseofgreenwasteasADCmaybelimitedduetolocalCityand/orCountypolicyofdivertinggreenwastefromthelandfillaswellasmandatorywastediversionassemblybill(AB1826andAB341).Otherstudieshavealsoinvestigatedbio‐tarp39asanalternativecovertoreduceemissionthatmaybeconsideredinstead.InadditiontorecommendationsmadebyHGCtousesprayonproductsasdailycover,werecommendinvestigatingthepossibilityofobtainingshreddedgreenwasteorcompostthatcouldalsobeusedasADC.Wealsosuggestinvestigatingtheuseofbio‐tarpasanalternativecovertoreduceemission.
Impact of Daily Cover Soil Use on Landfill Gas Transport and Emission Inordertobetterassesstheimpactofnine(9)inchesofdailycoveronlandfillgastransportandemission,analysisoftheeffectsofdailycoverongastransportpropertiesandwaterretentionisneeded.Werecommendtwomethodstofurthergatherdata.Inthefirstmethod,weproposethecollectionofin‐tactwastecoresamplesatvariousdepthsattheSCLusingsonicdrillingtechnique(Figure14)inconjunctionwithfreezingofsamples(tomaintainporestructure).Theeight(8)inchdiametersamplesthatarecontinuouslylinedwithplastictubeswillbeusedtocollectwastesamplesatdepthsandinlocationswithlittleornosignificantdailycover.ThesesampleswillbesenttotheUniversityofDelawarelaboratorieswheredensity,totalporosityandgastransportpropertieswillbemeasured.Whiletheinitialwatercontentofthesampleswillberecorded,theeffectofmoistureongastransportwillbeevaluatedbyvaryingthewatercontentsystematicallyineachsampleinthelaboratory.TheUniversityofDelawarehasconductedsimilarmeasurementsonotherwastesamples(Hanetal.,2011)40.Thisinformationwillquantifytheeffectofdailycoveronwaterretentionandgastransportproperties,informationthatmaybeusedinnumericalmodelingoflandfillgastransportandemissionsintheSCL.Inthesecondmethod,weproposetousein‐situcone
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penetrationtest(CPT)andpiezoconepenetrationtest(PCPT)(Figure15).Thisisafast,economicalmethodthatprovidescontinuousprofilingofwastetodeterminevariousconditionssuchas:locationofcompactedwasteandcoversoillayers,liquidandgaspressures,identifyzonesofvacuum,determinedensityofwasteasafunctionofdepth(Figure16).Werecommendthatastudybeconductedtogetabetterunderstandofhowthesoillayersusedasdailycoverimpactsgasandwatermovementinlandfill.Wecanprovideadetailedproposalforfurtherstudyatalaterdate.
Figure14‐WastesamplingusingaSonicdrillingunit
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Figure15‐ConePenetrationTest(CPT)procedureandsetup41.
Figure16‐TypicalPiezoconeConePenetration(PCPT)testresults41.
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Measurement of Whole‐Landfill Gas Emissions InSouthernCalifornia,themainanthropogenicemissionsourcesofCH4arelandfills(Table1)42.ThereareseveralfieldmethodstomeasurelandfillCH4emissionssuchasstaticanddynamicfluxchambermethodsatgroundlevel,subsurfaceconcentrationandpressuregradientmethods,andabovegroundmicrometeorologicalandtracermethods(Scheutzetal.,2009)43.Entirelandfillemissionscouldbemeasured(dynamicorstationary)usingatracer‐dilutionmethod,wheredownwindconcentrationofemissionmixedwiththereferencegastracerreleased(Figure17)ismeasured(Galleetal.,200144;Czepieletal.,199645;Tregouresetal.,199946).Suchmethodshaverecentlybeentestedandevaluatedforlandfillemissionquantification(Babilotte,201147;Goldsmithetal.,201248;Greenetal.,201049;Peischletal.,201350).CaliforniaAirResourcesBoard(ARB)ownsamobilemeasurementplatform(MMP)withequipmenttomeasuregreenhousegasemissions(e.g.,nitrousoxide(N2O,)‐tracergas,methane(CH4),andcarbondioxide(CO2))andiscurrentlyinuseintheLosAngelesarea.Werecommendthatanentirelandfillemissionmeasurement(dynamicorstationary)usingatracer‐dilutionmethodbeconducted.Werecognizethatapplyingthismethodtothissitecouldbechallengingbutitwillprovidemoreinsighttobetterunderstandthesourceofodors.WeproposetocoordinatewithARBinordertoconductwholelandfillemissionstestingusingthetracer‐dilutionmethod.IfARBisunabletoassistthenweproposetocoordinatewitheitherLosGatosResearch(LGR)locatedinMountainView,CaliforniaorPicarroinSantaClara,California.PicarroconductedsimilarpreliminarytestsofsuchmobilesetupattheYoloCountyCentralLandfill.BothcompanieshavedevelopedportableinstrumentstomeasureGHGwithlowdetectionlimitsneededforsuchemissionsstudy.Table1‐CARBYear2004statewideandSouthCoastAirBasin(SoCAB)portionofLACountyCH4inventories.42
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Figure17‐Schematicviewofdynamicdispersionmethodappliedatalandfill.1
Summary of Recommendations: InadditiontotherecommendationsintheHGCreport15werecommendthefollowing:1) Intermediate Cover Soil Testing‐Werecommendthecollectionofin‐tactcore
samplesofcoversoilatvariouslocations(topandsideslopes)attheSCLtobetterunderstandthepropertiesoftheon‐sitesoil.ThesesampleswillbesenttotheUniversityofDelawarelaboratorieswheredensity,totalporosityandgastransportpropertieswillbemeasured.Whiletheinitialwatercontentofthesampleswillberecorded,theeffectofmoistureongastransportwillbeevaluatedbyvaryingthewatercontentsystematicallyineachsampleinthelaboratory.TheseparameterscandirectlyimpacttheamountofLFGreleasedtotheatmospherethroughthecoversoilandthereforeincreasethepotentialodorattheSCL.
2) Daily Cover Soil‐Thefollowingtestsrelatedtotheuseofdailycoversoilarerecommended:a) Werecommendthatrepresentativesamplesofdailycoversoilstockpilebe
collectedandtestedforsulfurcontent.Samplesshouldalsobetestedforbiochemicalsulfurpotential(BSP)underanaerobicenvironmenttodetermineitspotentialforproductionofH2S.ThesetestswillbesenttoNorthCarolinaStateUniversityforlaboratorytesting.
b) Samplesofthelandfillleachatefromvariousleachatecollectionareasofthelandfillshouldalsobetestedforsulfate.
c) Landfillgassamplesfromvariouslocations(gaswellsandgasheaderlines)shouldbecollectedforH2Slaboratorytesting.
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d) Wealsorecommendtwotypesoffieldstudiestogatherdataandbetterunderstandhowthedailycoversoillayersimpactgasandwatermovementinlandfillandtheimpactithasongascollectionefficiencyandemissions.i) Inthefirststudy,weproposethecollectionofin‐tactcoresamplesof
wasteatvariousdepthsusingsonicdrillingtechniqueinconjunctionwithfreezingofsamples(tomaintainporestructure).ThesesampleswillbesenttotheUniversityofDelawarelaboratorieswheredensity,totalporosity,andgastransportpropertieswillbemeasured.Whiletheinitialwatercontentofthesampleswillberecorded,theeffectofmoistureongastransportwillbeevaluatedbyvaryingthewatercontentsystematicallyineachsampleinthelaboratory.Thisinformationwillquantifytheeffectofdailycoveronwaterretentionandgastransportproperties,informationthatmaybeusedinnumericalmodelingoflandfillgastransportandemissionsintheSCL.
ii) Inthesecondstudy,weproposetousein‐situconepenetrationtest(CPT)andpiezoconepenetrationtest(PCPT).Thisisafast,economicalmethodthatprovidescontinuousprofilingofwastetodeterminevariousconditionssuchas:locationofcompactedwasteandcoversoillayers,liquidandgaspressures,identifyzonesofvacuum,anddeterminedensityofwasteasafunctionofdepth.
3) Alternative Daily Cover (ADC)‐AssuggestedbyHGC15othertypesofADC
(sprayonproducts)shouldbeusedinsteadoftheon‐sitesoil,particularlybecauseofhighsulfatecontentofsoilthatcouldreactwithleachategenerated.Inadditiontosprayonproducts,werecommendinvestigatingthepossibilityofobtainingshreddedgreenwasteorcompostthatcouldbeusedasADC.TheuseofgreenwasteasADCmaybelimitedduetolocalCityand/orCountypolicyofdivertinggreenwastefromthelandfillaswellasmandatorywastediversionassemblybills(AB1826andAB341).Wealsosuggestinvestigatingtheuseofbio‐tarp51asADCtoreduceemission.
4) Estimation of LFG Generation Rate and LFG Collection Adjustment‐
a) Werecommendusingthebaro‐pneumaticmethodtoestimatingLFGgenerationbecauseitreducesuncertaintiesinestimationofLFGgenerationrates.
b) ThecurrentmethodofLFGwellheadadjustmententrainsairintothelandfillanddoesnottakeintoaccountthediurnalbarometricpressurechanges.Werecommendthatatleastonemainheaderlinewithseveralgaswellsandonegaswellintheareawherebaro‐pneumatictestswereperformedbyHGCbemodifiedwithanautomaticwellheadadjustmentsystem(LociControls23).Todeterminetheeffectivenessofreducinglandfillgasemissionswerecommendgastracermethod24beusedtomeasuretheactualgascollectionefficiencywithandwithouttheautomaticwellheadadjustmentsystem.
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5) Saturated Waste Condition and Gas Collection Efficiency‐Werecommendthatthenear‐surfacepermeablelayer31bedesigned,constructed,andtestedinanareawherewasteissaturatedandsurfaceemissionsareknowntobeaproblem.Thegascollectionefficiencywillbemeasuredbeforeandafterinstallationofthispermeablelayerusingthegastracermethod24.
6) Whole‐Landfill Gas Emissions‐Werecommendusingthetracer‐dilution
method(dynamicorstationary)toconductseveralweeksoffieldstudytodeterminetheentirelandfillemissionsunderdifferentatmosphericconditions.ResultswillbeusedtoidentifythelocationofgasemissionswithintheSCLsite.
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Appendix A
FigureA1‐SCLJointTechnicalDocument(JTD)2007,Proposed
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FigureA2‐SCLLocationofVerticalGasWellswithDedicatedPumpandBoundaryofnine(9)inchDailySoilCover
FigureA3‐HydroGeoChem,Inc.FieldTestLocationattheSCL
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Limitations NoinvestigationisthoroughenoughtoguaranteethefutureeliminationofodorattheSCLsite.WhilethisreportprovidesreasonablerecommendationsandsuggestsfurtherstudiestoimproveodorcontrolatSCL,itshouldnotbeconstruedasaguaranteethatthesuggestedideaswouldaccuratelyforecasttheeliminationofodorattheSCLsite.Theservicesdescribedinthisreportwereperformedconsistentwithgenerallyacceptedprofessionalconsultingprinciplesandpractices.Nootherwarranty,expressorimplied,ismade.Theseserviceswereperformedconsistentwithouragreementwithyou,ourclient.Thisreportissolelyfortheuseandinformationofourclientunlessotherwisenoted.Anyrelianceonthisreportbyathirdpartyisatsuchparty’ssolerisk.Opinionandrecommendationscontainedinthisreportapplytoconditionsexistingwhenserviceswereperformedandareintendedonlyfortheclient,purposes,locations,timeframesandprojectparametersindicated.Wearenotresponsiblefortheimpactstoanychangesinenvironmentalstandards,practices,orregulationssubsequenttoperformanceofservices.Wedonotwarranttheaccuracyofinformationsuppliedbyothers,ortheuseofsegregatedportionsofthisreport.
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List of References 1JacobMønster,(2014)“Quantifyinggreenhousegasemissionsfromwastetreatmentfacilities.”PhDThesis,DTUEnvironment,DepartmentofEnvironmentalEngineering,TechnicalUniversityofDenmark.2ManagingSolidWasteFacilitiestoPreventOdor”,NationalSolidWastesManagementAssociation(NSWMA).3“WorkingFaceStudySunshineCanyonLandfillSylmar,California”,ENVIRONInternationalCorporation,June14,2011.4“SunshineCanyonLandfillEvaluationoftheExistingLandfillGasCollectionandControlSystem”,TetraTechBAS,November29,2011.5“SunshineCanyonLandfillSupplementalWasteCharacterizationStudy”,TetraTech,Inc.andEcoTelesisInternational,May,2015.6“AssessmentofAlternativeDailyCoverRelatedtoOriginandControlofLandfillOdor”,BlueRidgeServices,December18,2012.7USEPA:LandfillGasEmissionsModel(LandGEM)Version3.02User’sGuide.EPA‐600/R‐05/047(2005).8EMCON:MethaneGenerationandRecoveryfromLandfills.AnnArborSciencePublishers,AnnArbor(1980).9El‐Fadel,M.,Findikakis,A.N.,Leckie,J.O.“NumericalmodelingofgenerationandtransportofgasandheatinlandfillsI.Modelformulation.”WasteManag.Res.14,483–504(1996).10Scharff,H.,Jacobs,J.“Applyingguidanceformethaneemissionestimationforlandfills.”WasteManag.26,417–429(2006).11Tolaymat,T.M.,Green,R.B.,Hater,G.R.,Barlaz,M.A.,Black,P.,Bronson,D.,Powell,J.“Evaluationoflandfillgasdecayconstantformunicipalsolidwastelandfillsoperatedasbioreactors.”J.AirWasteManag.Assoc.60,91–97(2010).12Wang,X.,Nagpure,A.S.,DeCarolis,J.F.,Barlaz,M.A.“UsingObservedDatatoImproveEstimatedMethaneCollectionfromSelectU.S.Landfills.”Environ.Sci.Technol.,2013,47(7):3251–3257.
34
13Bentley,H.W.,Smith,S.J.,Tang,J.,Walter,G.R.“Amethodforestimatingtherateoflandfillgasgenerationbymeasurementandanalysisofbarometricpressurewaves.”In:Proceedingsofthe18thInternationalConferenceonSolidWasteTechnologyandManagement,Philadelphia,PA(2003).14Walter,G.R.“Fatalflawsinmeasuringlandfillgasgenerationratesbyempiricalwelltesting.”J.AirWasteManag.Assoc.53,461–468(2003).15“PneumaticTestingandRecommendedChangesattheSunshineCanyonLandfill”,HydroGeoChem,Inc.,March11,2015.16http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_05357317Czepiel,P.M.,Shorter,J.H.,Mosher,B.,Allwine,E.,McManus,J.B.,Harriss,R.C.,Kolb,C.E.,Lamb.B.K.(2003).“Theinfluenceofatmosphericpressureonlandfillmethaneemissions.”WaterManagement23(7):593‐598.18Giani,L.,J.Bredenkamp,etal.(2002).“TemporalandspatialvariabilityoftheCH4dynamicsoflandfillcoversoils.”J.PlantNutr.SoilSci.,165,205–210.19Christophersen,M.,Kjeldsen,P.,Holst,H.,Chanton,J.(2001).“Lateralgastransportinsoiladjacenttoanoldlandfill:factorsgoverningemissionsandmethaneoxidiation.”WasteManag.Res.19(6):595‐612.20Xu,L.,Lin,X.,etal.(2014).“Impactofchangesinbarometricpressureonlandfillmethaneemission.”GlobalBiogeochemicalCycles28(7):679–695.21Czepiel,P.M.,J.H.Shorter,etal.(2003)."Theinfluenceofatmosphericpressureonlandfillmethaneemissions."WasteManagement23(7):593‐598.22Yazdani,R.,D.Augenstein,P.Imhoff,M.Barlaz.(2008),“DemonstrationofLandfillTechnologyforPeakingPowerPotentialatYoloCountyCentralLandfill.”CaliforniaEnergyCommission,PIEREnergy‐RelatedEnvironmentalResearchProgram.CEC‐500‐00‐034.23http://locicontrols.com24Yazdani,R.,Imhoff,P.T.,Han,B.,Mei,C.,Augenstein,D.(2015).“QuantifyingCaptureEfficiencyofGasCollectionWellswithGasTracers”,WasteManagement,43:319‐327.25Kjeldsen,P.andE.V.Fischer(1995)."LandfillGasMigration‐FieldInvestigationsatSkellingstedLandfill,Denmark."WasteManagement&Research13(5):467‐484.
35
26Borjesson,G.andB.H.Svensson(1997)."Seasonalanddiurnalmethaneemissionsfromalandfillandtheirregulationbymethaneoxidation."WasteManagement&Research15(1):33‐54.27Christophersen,M.,P.Kjeldsen,etal.(2001)."Lateralgastransportinsoiladjacenttoanoldlandfill:factorsgoverningemissionsandmethaneoxidation."WasteManagement&Research19(6):595‐612.28Czepiel,P.M.,J.H.Shorter,etal.(2003)."Theinfluenceofatmosphericpressureonlandfillmethaneemissions."WasteManagement23(7):593‐598.29Poulsen,T.G.,M.Christophersen,etal.(2003)."Relatinglandfillgasemissionstoatmosphericpressureusingnumericalmodelingandstate‐spaceanalysis."WasteManagement&Research21(4):356‐366.30Jung,Y.J.,P.T.Imhoff,etal.(2009)."Influenceofhigh‐permeabilitylayersforenhancinglandfillgascaptureandreducingfugitivemethaneemissionsfromlandfills."JournalofEnvironmentalEngineering‐ASCE135(3):138‐146.31Augenstein,D.C.,Benemann,J.R.,Yazdani,R.,“LandfillDesignandMethodforImprovedLandfillGasCapture”.U.S.PatentNo.7,198,433(2007).32Jung,U.,Imhoff,P.T.,Augenstein,D.,Yazdani,R.(2011).“Mitigatingmethaneemissionsandairintrusioninheterogeneouslandfillswithahighpermeabilitylayer”.WasteManagement31(5):1049‐1058.33Jain,P.,Powell,J.,Townsend,T.G.,Reinhart,D.R.,(2005).“Airpermeabilityofwasteinamunicipalsolidwastelandfill.”J.Environ.Eng.131(11),1565–1573.34Reinhart,D.R.,McCreanor,P.T.,Townsend,T.G.,(2002).“Thebioreactorlandfill:itsstatusandfuture.”WasteManage.Res.20,172–186.35McCreanor,P.T.,Reinhart,D.R.,(2000).“Mathematicalmodelingofleachateroutinginaleachaterecirculatinglandfill.”WaterRes.34(4),1285–1295.36“GeologicandGeotechnicalInvestigationReportforSunshineGasProducersLandfillGastoEnergyProjectatSunshineCanyonLandfill”,preparedbyAMECforHRGreen,Inc.,November15,2011.37Scheutz,C.,Pedersen,R.B.,Petersen,P.H.,Jørgensen,J.H.B.,Ucendo,I.M.B.,Mønster,G.M.,Samuelsson,J.,Kjeldsen,P.(2014).“MitigationofmethaneemissionfromanoldunlinedlandfillinKlintholm,Denmarkusingapassivebiocoversystem.”,WasteManagement,34(7):1179‐1190.
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38Mei,C.,Yazdani,R.,Han,B.,Mostafid,M.E.,Chanton,J.,VanderGheynst,J.,Imhoff,P.(2015).“Performanceofgreenwastebiocoversforenhancingmethaneoxidization.”,WasteManagement,39(1):205‐215.39Adams,B.L.,Besnard,F.,Bogner,J.,Hilger.H.,(2011).“Bio‐tarpalternativedailycoverprototypesformethaneoxidationatopopenlandfillcells.”,WasteManagement,31(5):1065‐1073.40Han,B.,Scicchitano,V.,Imhoff,P.T.,(2011).“Measuringfluidflowpropertiesofwasteandassessingalternativeconceptualmodelsofporestructure.”,31(3),344‐456.41“SubsurfaceInvestigations‐GeotechnicalSiteCharacterizationReferenceManual”,(May2002).U.S.DepartmentofTransportationFederalHighwayAdministration.PublicationNo.FHWANHI‐01‐021.42Hsu,Y.,VanCuren,T.,Jakober,C.,Herner,J.,FitzGibbon,M.,Blake,D.R.,Parrish,D.D.,(2010).“MethaneemissionsinventoryverificationinsouthernCalifornia,AtmosphericEnvironment,44(1):1‐7.43Scheutz,C.,Samuelsson,J.,Fredenslund,A.M.,Kjeldsen,P.,(2011).“Quantificationofmultiplemethaneemissionsourcesatlandfillsusingadoubletracertechnique.”WasteManage.,31(5):1009–1017.44Galle,B.,Samuelsson,J.,Svensson,B.H.,Borjesson,G.,(2001).“MeasurementsofmethaneemissionsfromlandfillsusingatimecorrelationtracermethodbasedonFTIRabsorptionspectroscopy.”EnvironmentalScience&Technology35(1),21–25.45Czepiel,P.,Mosher,B.,Harris,R.,Shorter,J.H.,McManus,J.B.,Kolb,C.E.,Allwine,E.,Lamb,B.,(1996).“LandfillCH4emissionsmeasuredbyenclosureandatmospherictracermethods.”JournalofGeophysicalResearch101,16711–16719.46Tregoures,A.,Beneito,A.,Berne,P.,Gonze,M.A.,Sabroux,J.C.,Pokryszka,Z.,Savanne,D.,Tauziede,C.,Cellier,P.,Laville,P.,Milward,R.,Arnaud,A.,Levy,F.,Burkhalter,R.,(1999).“Comparisonofsevenmethodsformeasuringmethanefluxatamunicipalsolidwastelandfillsite.”WasteManagementandResearch17,453–458.47Babilotte,A.(2011).“Fieldcomparisonofmethodsforassessmentofmethanefugitiveemissionsfromlandfills.”ReportforEnvironmentalResearch&EducationFoundation.127pp.http://erefdn.org/publications/uploads/FugitiveEmissions_FinalReport.pdf(accessedApril2015)48Goldsmith,J.,C.Douglas,Chanton,J.,Abichou,T.,Swan,N.,Green,R.,&Haters,G.(2012).“Methaneemissionsfrom20landfillsacrosstheUnitedStatesusingvertical
37
radialplumemapping.”,JournaloftheAirandWasteManagementAssociation,62(2):183‐197.49Green,R.B.,Hater,G.R.,Thoma,E.D.,Dewees,J.,Rella,C.W.,Crosson,E.R.,Gold‐smith,C.D.&Swan,N.(2010).“MethaneEmissionsMeasuredatTwoCaliforniaLandfillsbyOTM‐10andanAcetyleneTracerMethod.”,InGlobalWasteManagementSymposium2010,SanAntonio,TX,USA.50Peischl,J.,etal.(2013)“QuantifyingSourcesofMethaneUsingLightAlkanesintheLosAnglesBasin,California.”,J.Geophys.Res.Atmos.118:4974‐4990.51Adams,B.L.,Besnard,F.,Bogner,J.,Hilger.H.,(2011).“Bio‐tarpalternativedailycoverprototypesformethaneoxidationatopopenlandfillcells.”,WasteManagement,31(5):1065‐1073.