UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYREGION577WESTJACKSONBOULEVARDCHICAGO,IL60604-3590AUG192014TheHonorableMichaelR.PenceGovernorofIndiana100NorthSenateAvenueIndianapolis,Indiana46204DearGovernorPence:REPLYTOTHEATIENTIONOF:Thankyouforyourrecommendation(s)datedDecember12,2013,andaddendumdatedMay12,2014,ofairqualitydesignationsforthe2012revisedprimaryannualfineparticle(PM2.s)NationalAmbientAirQualityStandard(NAAQS)throughoutIndiana.IappreciatetheinformationIndianasharedwiththeU.S.EnvironmentalProtectionAgencyaswemoveforwardtoimprovePM2.sairquality.ThisletteristonotifYyouofEPA'spreliminaryresponsetoIndiana'srecommendationandtoinformyouofourapproachforcompletingtheinitialareadesignationsforthe2012revisedprimaryannualPM2sstandard.OnDecember14,2012,EPApromulgatedarevisedprimaryannualPM2.sNAAQS(78FR3086,January15,2013).Inthataction,EPArevisedtheprimaryannualPM2.sstandard,strengtheningitfrom15.0microgramspercubicmeter()lg/m3)to12.011g/m3;retainedtheexisting24-hourPM2.sstandardat3511g/m3;retainedtheexisting24-hourPMto(coarseparticle)standardat15011g/m3;andretainedthecurrentsuiteofsecondaryPMstandards.EPArevisedtheprimaryannualPM2.sstandardbasedonanintegratedassessmentofanextensivebodyofnewscientificevidence,whichsubstantiallystrengthensourbodyofknowledgeregardingPM2.s-relatedhealtheffects.TherevisedprimaryannualPM2.sstandardwillprovideincreasedprotectionforchildren,olderadults,personswithpre-existingheartandlungdisease,andotherat-riskpopulationsagainstanarrayofPM2.s-relatedadversehealtheffects,includingprematmemortality,increasedhospitaladmissionsandemergencydepartmentvisits,anddevelopmentandexacerbationofchronicrespiratorydisease.Historyshowsusthatbetterhealthandcleanerairgohand-in-handwitheconomicgrowth.Workingcloselywiththestatesandtribes,EPAisimplementingthestandardsusingacommonsenseapproachthatimprovesairqualityandminimizestheburdenonstate,local,andtribalgovernments.Aspartofthisprocess,EPAisworkingwiththestatesandtribestoidentifyareasinthecountrythatmeetthestandardsandthosethatneedtotakestepstoreducePM2.sairpollution.Withinoneyearofpromulgationofaneworrevisedairqualitystandard,theCleanAirActrequirestheGovernorofeachstatetosubmittoEPAalistofallareasinthestate,withadesignationrecommendationforeacharea.Asafirststepinimplementingthe2012annualPM2.sstandard,Governorsweretosubmittheirdesignationrecommendations,includingappropriateareaboundaries,byDecember13,2013.Recycled/Recyclable•PrintedwithVegetableOilBasedInkson100%RecycledPaper(100%Post-Consumer)AsrequiredbytheCleanAirAct,EPAthenpromulgatesdesignationsforallareasacrossthecountry.EPAdesignatesanareaas"nonattainment"ifitisviolatingthe2012annualPM2.sNAAQSorifitiscontributingtoaviolationoftheNAAQSinanearbyarea.ConsistentwithdesignationsforpreviousPM2.sstandards,EPAintendstouseadesignationcategoryof"unclassifiable/attainment"forareasthataremonitoringattainmentordonothavemonitors,butforwhichEPAhasreasontobelievearelikelyattainmentandarenotcontributingtonearbyviolations.Additionally,EPAintendstodesignateas"unclassifiable"thoseareaswhereEPAcannotdeterminebasedonavailableinformationwhethertheareaismeetingtheNAAQSorwhereEPAhasnotdeterminedthattheareacontributestoanearbyviolation.Atthistime,EPAisproceedingwithinitialareadesignationsusingquality-assured,certifiedairqualitymonitoringdatafrom2011to2013.EPAhasreviewedIndiana'sDecember12,2013andMay12,2014designationrecommendationsandotherrelevanttechnicalinformation,including2011-2013airqualitydata,andEPAintendstomodifyIndiana'srecommendedareadesignationsfortheLouisville,KY-INandtheChicago,IL-INareas.TheintendedLouisville,KY-INnonattainmentareareflectsviolationofthe2012annualPM2.sNAAQSinClarkCounty,Indiana.The2011-2013datadonotindicateanyviolationofthe2012annualPM2sNAAQSinNorthwestIndiana.However,arecentEPA-conductedtechnicalsystemsauditofIllinois'monitoringprogramrevealeddataqualityissuesintheChicagoareaandelsewhereinIllinoiswhichaffectthedesignationsforLakeandPorterCountiesinIndiana.BecausemanyifnotalloftherecentPM2.smonitoringdatainIllinoismustbeconsideredinvalid,EPAcannotdeterminewhetherthecountiesintheIllinoisportionoftheChicagoarea(andelsewhereinIllinois)aremeetingornotmeetingtheNAAQSorwhethercmmtiesnearbytothoseIllinoiscounties,includingtwocountiesinNorthwestIndiana,contributetoanearbyviolation.Accordingly,EPAintendstomodifyIndiana'srecommendedareadesignationanddesignateLakeandPmiercountiesasunclassitlable.TechnicalSupportDocuments,whichprovideadditionaldetailregardingourpreliminarydecisions,areenclosedandarealsoavailableonEPA'swebsiteatEPAintendstodesignateallotherareasofthestateasunclassifiable/attainment.EPAwillcontinuetoworkwithstateofficialsregardingtheappropriateboundariesfortheareasinIndiana.lfIndianahasadditionalinfonnationforEPAtoconsider,pleasesubmitittousbyOctober29,2014.EPAwillmakeitsproposeddesignationdecisionsandsupportingdocumentationavailabletothegeneralpublicforreviewandcomment.Wewillbeam1ouncinga30-daypubliccommentperiodshortlyintheFederalRegister.Afterconsideringanyadditionalinformationwereceive,EPAplanstopromulgatefinalannualPM2.sdesignationsinDecemberof2014.EPAiscommittedtoworkingwiththestatesandtribestosharetheresponsibilityofreducingPM2.sairpollution.Currentandupcomingfederalstandardsandsafeguards-includingpollutionreductionrulesforpowerplants,vehicles,andfuels-willensuresteadyprogresstoreducePM2s-formingpollutionandwillprotectpublichealthincommunitiesacrossthecountry.Welookforwardtoacontinueddialoguewithyouandyourstaffasweworktogethertoimplementthe2012annualPM2sstandard.Ifyouanyquestions,pleasecontactmeoryourstaffmaycontactRonnaBeckmannorEileenDeamer,theRegion5IntergovernmentalLiaisons,at(312)886-3000.Sincerely,<SusanHedmanRegionalAdministratorEnclosurescc:TomEasterlyCommissioner,IndianaDepartmentofEnvironmentalManagementKeithBauguesAssistantCommissioner,OfficeofAirQualityIndianaDepartmentofEnvironn1entalManagement