INDIANADEPARTMENTOFENVIRONMENTALMANAGEMENTWeProtect HoosiersandOurEnvironment.MichaelR.PenceGovernorThomasWEasterlyCommissionerMs.SusanHedmanRegionalAdministratorU.S.EnvironmentalProtectionAgencyRegionV77WestJacksonBoulevardChicago,IL60604-3950DearMs.Hedman:October22,2014100NorthSenateAvenueIndianapolis,Indiana46204(317)232-8603TollFree(800)451-6027www.idem.IN.govRe:Designationsunderthe2012NationalAmbientAirQualityStandardforParticulateMatter(PM2.s)TheIndianaDepartmentofEnvironmentalManagement(IDEM)haspreparedthisletterinresponsetoUnitedStatesEnvironmentalProtectionAgency's(U.S.EPA)August19,2014,letterconcerningproposeddesignationsforthe2012NationalAmbientAirQualityStandard(NAAQS)forparticulatematter(PM2.5).IDEMgreatlyappreciatestheopportunitytoprovidecommentontheproposeddesignationsandwouldliketothankU.S.EPAfortakingourrecommendationsintoaccountwhenproposingthesedesignations.U.S.EPAproposedtodesignatebothClarkandFloydCountiesintheLouisville,KY-INareaasnonattainmentbecauseoneofthemonitorslocatedinClarkCounty(180190006-JeffersonvilleWalnutSt.)measureda2011-2013designvalueof12.1I-Jg/m3,0.1I-Jg/m3abovetheannualstandardof12.0I-Jg/m3.IDEMisconfidentthatthismonitorwillattainthePM2.sstandardatthecloseof2014.Throughthethirdquarterof2014,the2012-2014designvaluefortheJeffersonvilleWalnutSt.monitoris11.91-Jg/m3.Acalculationofthefourthquartercriticalvaluedeterminedthatamonitoredvalueof14.5IJQ/m3isneededinorderforthemonitortobeinviolationofthestandardatthecloseof2014.Atrendanalysisofhistoricaldata(fourthquartersof2009-2013)fromtheWalnutSt.monitorindicatesthatavalueof10.8I-Jg/m3shouldbeexpectedforthefourthquarterof2014.ThiswouldresultintheWalnutSt.monitorattainingthestandard.Figure1belowshowsthatthefourthquarteraveragehasbeendecreasingforthepastfiveyearsandthe2014projectionis.wellbelowthecriticalvalueneededforthemonitortoviolatethestandard.ItisalsoworthnotingthattheWalnutSt.monitorhasnotrecordedafourthquarterof14.5I-Jg/m3orhigherwithinthepastfiveyears.RecycledPaper@AnEqualOpportunityEmployerPleaseRecycleOS.HedmanPage2.2009-2013PM2.5FourthQuarterAverage&Projected2014Value-4-Linear(Average(llg/m3))200920102011201220132014IDEMwillcertifyandsubmitthemonitoringdataasearlyaspossibleafterthecloseof2014,butcertainlynolaterthanJanuary30,2015.ThiswillprovideU.S.EPAwiththemostcurrentdatainordertoreconsidertheclassificationforClarkandFloydCountiespriortodesignationbecomingeffective.Itisourunderstandingthatifthe2012-2014designvaluefortheJeffersonvilleWalnutSt.monitorisbelowthestandardthatU.S.EPAintendstodesignatebothClarkandFloydCountiesas"unclassifiable"duetouncertaintieswithmonitoringdatacollectedbytheLouisvilleAirPollutionControlDistrict.Indianaagreesthatthiswouldbethemostappropriatedesignation/classificationforthosecounties.WithregardtoU.S.EPA'srecommendationthatbothLakeandPorterCountiesinNorthwestIndianabedesignated"unclassifiable"duetouncertaintieswithmonitoringdatawithintheChicago-areamonitoringnetwork,IDEMunderstandsU.S.EPA'srationale.However,thecertifieddatacollectedbyIndiana'snetworkwithinLakeandPorterCountiesshouldbesufficientforU.S.EPAtoclassifyLakeandPorterCountiesasattainment.IwouldliketothankyoufortheopportunitytoprovideadditionalfeedbacktoU.S.EPAregardingtheproposeddesignationsforthe2012PM2.sNAAQS.WelookforwardtoworkingwithyourstaffasU.S.EPAmovesforwardwithfuturedesignations.IfyouhaveanyquestionsregardingIDEM'sresponse,pleasefeelfreetocontactmeat(317)232-8611orKeithBaugues,AssistantCommissioner,OfficeofAirQuality,at(317)232-8222.S.HedmanPage3.TE/kbcc:JohnSummerhays,U.S.EPADougAburano,U.S.EPAKeithBaugues,IDEMSeanAlteri,KDAQ