UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYREGION577WESTJACKSONBOULEVARDCHICAGO,IL60604-3590FEB162016REPLYTOTHEATTENTIONOF:TheHonorableScottWalkerGovernorofWisconsin115EastCapitolMadison,Wisconsin53702DearGovernorWalker:ThankyouforyourrecommendationsdatedSeptember16,2015onairqualitydesignationsfortheStateofWisconsinforthe2010revisiontotheprimaryNationalAmbientAirQualityStandard(NAAQS)forsulfurdioxide(S02).ReducinglevelsofS02pollutionisanimportantpartoftheU.S.EnvironmentalProtectionAgency'scommitmenttoaclean,healthyenvironment.ExposuretoS02cancausearangeofadversehealtheffects,includingnarrowingoftheairwayswhichcancausedifficultybreathingandincreasedasthmasymptoms.ThisletteristonotifyyouofEPA'spreliminaryintentionsregardingyourrecommendeddesignations.OnJune3,2010,EPAstrengthenedthehealth-basedor"primary"standardforS02byestablishingastandardfor1-houraverageS02concentrationsatalevelof75partsperbillion.Withinoneyearafteraneworrevisedstandardisestablished,theCleanAirActrequirestheGovernorofeachstatetosubmittoEPAalistofallareasinthestate,withrecommendationsforwhethereachareameetsthestandard.Throughaninteractiveprocess,EPAconsiderstherecommendationsandthenpromulgatesdesignationsforallareasacrossthecountry.OnJuly25,2013,EPAdesignated29areasin16statesasnonattainmentbasedonmonitoredviolations,butdidnotatthattimedesignateotherareas.PursuanttoaMarch2,2015,court-orderedschedule,1EPAmustcompletetheremainingS02designationsbythreespecificdeadlines:July2,2016,December31,2017,andDecember31,2020.Thiscurrentroundofdesignations,tobecompletedbyJuly2,2016,addressestwogroupsofareas:(1)areasthathavenewlymonitoredviolationsofthe2010S02NAAQSbasedonthemostrecentthreecalendaryearsofcertifiedmonitoredambientairqualitydata,and(2)areasthatcontainanystationarysourcethathadnotbeenannouncedasofMarch2,2015,forretirementandthataccordingtoEPA'sAirMarketsDatabaseemittedin2012either(i)morethan16,000tonsofS02or(ii)morethan2,600tonsofS02withanannualaverageemissionrateofatleast0.45poundsofS02/MMBTU.1SierraClubv.McCarthy,No.3-13-cv-3953(Sl)(N.D.Cal.Mar.2,2015).Recycled/Recyclable•PrintedwithVegetableOilBasedInkson100%RecycledPaper(100%Post-Consumer)AftercarefullyconsideringWisconsin'srecommendationsandotheravailabletechnicalinformation,EPAintendstodesignateasunclassifiable/attainmentthefollowingarea,includingthefollowingcounty:IntendedUnclassifiable/AttainmentAreaColumbiaCountyIntendedUnclassifiable/AttainmentAreaCountiesColumbiaCountyBecausetheMarch2,2015consentdecreedirectsEPAtoevaluatedatacollectedforthemostrecent3years,EPAinitiallyidentifiedBrownCountyasanareathatwouldpotentiallybesubjecttoanobligationforustodesignatebyJuly2,2016.AmbientairqualitydataforBrownCountycollectedbetween2012and2014indicatedaviolationofthe2010S02NAAQS.However,yourstaffpromptlyevaluatedBrownCounty's2015dataandcertifieditasaccurateonJanuary29,2016.Asaresult,complete,qualityassured,andcertifieddatafor2013to2015forBrownCounty,Wisconsinindicatecompliancewiththe2010SOzNAAQS.Therefore,EPAintendstodesignatethisareaatalaterdate,byeitherDecember31,2017,orDecember31,2020.TheenclosedTechnicalSupportDocumentprovidesadetailedanalysisthatsupportsourintendeddesignationdecisions.IfyourstatehasadditionalinformationthatEPAshouldconsiderpriortofinalizingthesedesignations,pleasesubmitittousbyApril19,2016.WealsowillbepublishinganoticeintheFederalRegisterannouncinga30-dayperiodforthepublictoprovideinputonEPA'sintendeddesignationdecisions.WewillpromulgatethedesignationsfortheseareasbyJuly2,2016.Wewilldesignateallotherpreviouslyundesignatedareasinthestateonascheduleconsistentwiththeprescribedtimingofthecourtorder,i.e.,byDecember31,2017,orDecember31,2020.Welookforwardtoacontinueddialoguewithyouandyourstaffasweworktogethertocompletetheareadesignationsandimplementthe2010primarySOzstandard.ForadditionalinformationregardingdesignationsundertheSOzstandard,pleasevisitourwebsiteatwww.epa.gov/so2designations.Shouldyouhaveanyquestions,pleasedonothesitatetocallme,orhaveyourstaffcontactmeat312-886-3000,orGeorgeCzerniak,Director,AirandRadiationDivision,at312-353-2212orczemiak.george@epa.gov.Sincerely,r.:i?drJ--4:-RobertA.KaplanActingRegionalAdministratorEnclosurecc:CathyStepp,SecretaryWisconsinDepartmentofNaturalResourcesGailGood,DirectorBureauofAirManagementWisconsinDepartmentofNaturalResources