EDS7.UNITEDSTATESENVIRONMENTALPROTECTIONAGENCYX\IILREGIONIX75HawthorneStreetSanFrancisco,CA94105-3901FEB062013OFFICEREGIONALADMINISTRATORTerryRamblerChairmanSanCarlosApacheTribeP.O.Box0SanCarlos,Arizona85550DearChairmanRambler:ThisletterregardsairqualitydesignationsfortheSanCarlosApacheTribeforthe2010revisiontotheprimaryNationalAmbientAirQualityStandardforsulfurdioxide(SO2).ReducinglevelsofSO2pollutionisanimportantpartoftheU.S.EnvironmentalProtectionAgency’s(EPA)commitmenttoaclean,healthyenvironment.ExposuretoSO2cancausearangeofadversehealtheffects,includingnarrowingoftheairwayswhichcancausedifficultybreathingandincreasedasthmasymptoms.ThisletteristonotifyyouoftheEPA’spreliminaryintentiontodeferdesignationofIndiancountryoftheSanCabsApacheTribe,andofourintentiontodesignatetwonearbyareas,HaydenandMiami,asnonattainment.OnJune3,2010,theEPAstrengthenedthehealth-basedor“primary”standardforSO2byestablishingastandardfor1-houraverageSO2concentrationsatalevelof75partsperbillion.TheCleanAirActrequirestheEPAtocompletetheinitialdesignationsprocesswithintwoyearsofpromulgatinganeworrevisedstandard.IftheAdministratorhasinsufficientinformationtomakethesedesignations,theEPAhastheauthoritytoextendthedesignationprocessbyuptooneyear.OnJuly27,2012,theEPAannouncedthatithadinsufficientinformationtocompletethedesignationsforthe1-hourSO2standardwithintwoyearsandextendedthedesignationsdeadlinetoJune3,2013.AtthistimetheEPAisproceedingwithdesignatingasnonattainmentmostareasinlocationswhereexistingmonitoringdatafrom2009-2011indicateviolationsofthe1-hourSO2standard.TheEPAintendstoaddressthedesignationsforallotherareasinseparatefutureactions.Withinputfromadiversegroupofstakeholders,EPAhasdevelopedacomprehensiveimplementationstrategyforthesefutureactionsthatfocusesresourcesonidentifyingandaddressingunhealthylevelsofSO2.Thestrategyisavailableat:www.epa.gov/airguality/sulfurdioxide/implement.html.TheEPAwillcontinuetoworkcloselywithyouandourotherpartnersatthestate,tribalandlocallevelstoensurehealthprotective,commonsenseimplementationofthe1-hourSO2standard.TheEPA’sreviewofthemostrecentmonitoredairqualitydatainArizonafrom2009-2011showsthatonlymonitorsinHaydenandMiamiareviolatingthe2010SO2standard.WedonotbelievethesemonitorsrepresenttheS02concentrationsonyourreservation,nordowebelievethereareSO2sourcesPrintedonReyc1edPaperlocatedontheSanCarlosApachereservationthatarecontributingtotheSO2concentrationsmonitoredatHaydenorMiami.Consequently,theEPAisnotyetpreparedtoproposedesignationactionforIndiancountryoftheSanCarlosApacheTribeandisthereforecurrentlydeferringdesignationactionforthisareaatthistime.TheEPAexpectstobeabletoproceedwithdesignationactioninyourTribe’sareaofIndiancountryonceadditionaldataaregatheredpursuanttoourcomprehensiveimplementationstrategy.InaseparatefutureactionoractionstheEPAwillnotifyyouofourintendedproposeddesignationsfortheseareas,offerconsultation,andseekpubliccommentontheseactions,nolaterthan120dayspriortopromulgatinganyfinaldesignations.Welookforwardtoacontinueddialoguewithyouandyourstaffasweworktogethertoimplementthe2010primarySO2standard.ForadditionalinformationregardinginitialdesignationsoftheSO2standard,pleasevisitourwebsiteat:www.epa.gov/so2designations.Shouldyouhaveanyquestions,pleasedonothesitatetocallme,orhaveyourstaffcontactDeborahJordan,Director,AirDivisionat415-947-8715,orjordan.deborah(epa.gov.Sincerely,,JaredBlumenfeldcc:LorettaStone,Director,SanCarlosEnvironmentalProtectionAgencyGinaMcCarthy,AssistantAdministratorforAirandRadiationStephenD.Page,Director,OfficeofAirQualityPlanningandStandards