WPC >1 % uuayt6rvBGa^QX?,s<.ե_χu'܆lA_Y0epc:2-=]r1 mEYcp"&*Z" ~Ul @Bx]2[<,g2mA|!@ rQ?~MԽҕѨr ːĬD*=sp$"" ?a> Њ(;I+t|0 b {ڊ(Ȋ B&Jk=l|  $CeɚAkq\ ҭ>w fK눚iU'Ji\[{#H"i'#ve(xNV>= x^#!!Rz2Q FJL5X*,"1.X0cѥ8Sg\Kl#UN % 0:N7UF9^ w4 mUuF 0N\_8:- 04 03E 0U 0\ 0EJ+ 0u! 0X" 08# 0$ 0$ 0% 0C& 0& 0' 0( 0Y) 0'* 0* 0+ 0, 0@?- 0- 0S. 0$/ 0/ 00 01 0J2 0 3N3U83 1u4 72x4Z4 726N66 04c86 06&7 0.7 07 08 0G9 0": 0 E; 1 V< 72< 0= 0= 0> 0? 0@ 0{A 0VTB 0B 0C 0 wSD 0D 0E 0pF 0CG 0H 0H 0I 0qJ 05K 0K 0L 0M 0[N 0*O 0O 0P BQ 0Q 0eR 0%SS 1lUU 72X 0I4X 72Y 1DY 72Y 1Y 72Z 72ZNZ 72ZU([[D[D[D[D[[[ 72^^^^-^^ 1 _ _ 72_ 1_ 72K`K`}`^bfecagc 1{c 72d 1 4d 72d 1d 72teelf2ggh Ai/j Aj 0Vk D5k D-+l 0KXl 0Vl ASl 0DLm 1m 72nnn 72In6{n 72nNn 72n 72oo 72IoN{o 72}o}o 72oU6oNp 72p+Kpgvufy1C{C{C{C{C{C{C{C{%ttpPL^( 72m 72 72њ 72 725NgNiiii 72k 72 72ϛ 72 723 72e 72 72ɜ 72 72-N_ 72aN 72 1ǝ 72V 72N 72 72N """p 0VZsssssͦ\FvvBbbz 18F3dN 72! 72SN 72 72 72 72 72O 72N 72 72 72 72K 72} 72 72 72 72E 72wN 72N 72 72NC 72E 72wN 72N9UF2^N8G<A[ Tdd\\US_EPA\AQSSD_C545 HP8000.MUTUAL.OAQPS.RTP.EAST.EPA0(9 Z6Times New Roman RegularX($USUS.,.Courier New Regular0s (s0x3|xU<4 9Z+.Courier New Regular(O$http://www.wpea.gov/ttn/naaqs/ozone/o3imp8hr.mailto:silvasi.john@epa.govmailto:gerth.denise@epa.gov. $USUS.,2XcXXX `   2    _AmericanLungAssociationv.EPA(D.D.C.No.  1:02CV02239).([(2$ !USUS.,  2XcXXX `   0  (C$  41  *+ (_2623  ..*G+M (_25   /%` ` hp x /23  ..  5+ ` hp x 5  *D+M (_24   ," hp x ,23  ..  5+ ` hp x 5   @ $USUS.,2XcXXX `   1    _Section107(d)oftheCAAsetsforthaschedulefor  designationsfollowingthepromulgationofaneworrevised  NAAQS.TheTransportationEquityActfortheTwentyfirst \ Century(TEA21)revisedthedeadlinetopromulgate 2 nonattainmentdesignationstoprovideanadditionalyear(to X July2000)butHR3645(EPAsappropriationbillin2000) . restrictedEPAsauthoritytospendmoneytodesignateareas   untilJune2001orthedateoftheSupremeCourtrulingin   thelitigationchallengingtheNAAQS,whichevercamefirst.*A+M (_23  ` ) hp x )23  ..  5+ ` hp x 5  *>+M (_22   &hhp x &23  ..  5+ ` hp x 5  *;+M (_21   #p x #23  ..  5+ ` hp x 5  *8+M (_20  h  p x 23  ..  5+ ` hp x 5  *5+M (_19   pp x 23  ..  5+ ` hp x 5  *2+M (_18    x 23  ..  5+ ` hp x 5  * (_1723  Ԁ*GM (_16   /%` ` hp x /23  Ԁ  5+ ` hp x 5  *DM (_15   ," hp x ,23  Ԁ  5+ ` hp x 5  *AM (_14  ` ) hp x )23  Ԁ  5+ ` hp x 5  *>M (_13   &hhp x &23  Ԁ  5+ ` hp x 5  *;M (_12   #p x #23  Ԁ  5+ ` hp x 5  *8M (_11  h  p x 23  Ԁ  5+ ` hp x 5  *5M (_10   pp x 23  Ԁ  5+ ` hp x 5  (2M &_9    x 23  Ԁ  5+ ` hp x 5  ( &_823  (GM &_7   /%` ` hp x /23   5+ ` hp x 5  (DM &_6   ," hp x ,23   5+ ` hp x 5  (AM &_5  ` ) hp x )23   5+ ` hp x 5  (>M &_4   &hhp x &23   5+ ` hp x 5  (;M &_3   #p x #23   5+ ` hp x 5  (8M &_2  h  p x 23   5+ ` hp x 5  (5M &_1   pp x 23   5+ ` hp x 5  &2M $_    x 23   5+ ` hp x 5  <4 9Z+ Courier New 3#37=CIQYag1.a.i.(1)(a)(i)1)a)3i) P $USUS.,2XcXXX `   3    _Weusetheterm revocationasshorthandfora  determinationunder40CFR50.9(b)thatthe1hourNAAQSno  longerappliestooneormoreareas.3i)(;$2  a  .3  0  (c<$0  0` (#(#2  a  .3  0 ` (#` (# (wH$0  0` (#(#0 ` (#` (#2  a  .3  0 (# (#(֧$0  0` (#(#0 ` (#` (#0 (# (#2  a  .3  0h(#(#(/$0  0` (#(#0 ` (#` (#0 (# (#0h(#(#2  a  .3  0h(#h(#($0  0` (#(#0 ` (#` (#0 (# (#0h(#(#0h(#h(#2  a  .3  0(#(#(;$0  0` (#(#0 ` (#` (#0 (# (#0h(#(#0h(#h(#0(#(#2  a  .3  0p(#(#(&'$0  0` (#(#0 ` (#` (#0 (# (#0h(#(#0h(#h(#0(#(#0p(#(#2   a   .3  0p(#p(# 8L9;<=>?xGaeimquy}Bullet ListBullets ListA@2D+G 0_level1  X ,"` ` hp x,23  ..  /% ` hp x/  2A+G 0_level2   ) hp x)23  ..  /% ` hp x/  2>+G 0_level3   &hp x&23  ..  /% ` hp x/  2;+G 0_level4  ` #hhp x#23  ..  /% ` hp x/  28+G 0_level5    p x 23  ..  /% ` hp x/  25+G 0_level6   p x23  ..  /% ` hp x/  (.3$ !USUS.,  22+G 0_level7  h pp x23  ..  /% ` hp x/  2/+G 0_level8     x23  ..  /% ` hp x/  (O$0  2  a  .3  0` (#(#2,+G 0_level9      x23  ..  /% ` hp x/  2DG 0_levsl1  X ,"` ` hp x,23  Ԁ  /% ` hp x/  2AG 0_levsl2   ) hp x)23  Ԁ  /% ` hp x/  2>G 0_levsl3   &hp x&23  Ԁ  /% ` hp x/  2;G 0_levsl4  ` #hhp x#23  Ԁ  /% ` hp x/  28G 0_levsl5    p x 23  Ԁ  /% ` hp x/  25G 0_levsl6   p x23  Ԁ  /% ` hp x/  22G 0_levsl7  h pp x23  Ԁ  /% ` hp x/  2/G 0_levsl8     x23  Ԁ  /% ` hp x/  2,G 0_levsl9      x23  Ԁ  /% ` hp x/  2DG 0_levnl1  X ,"` ` hp x,23   /% ` hp x/  2AG 0_levnl2   ) hp x)23   /% ` hp x/  2>G 0_levnl3   &hp x&23   /% ` hp x/  2;G 0_levnl4  ` #hhp x#23   /% ` hp x/  28G 0_levnl5    p x 23   /% ` hp x/  25G 0_levnl6   p x23   /% ` hp x/   d22G 0_levnl7  h pp x23   /% ` hp x/  2/G 0_levnl8     x23   /% ` hp x/  2,G 0_levnl9      x23   /% ` hp x/    $USUS.,2XcXXX `   5    _StateImplementationPlans;GeneralPreambleforthe  ImplementationofTitleIoftheCAAAmendmentsof1990;  ProposedRule.April16,1992(57FR13498at13501and \ 13510).(%EGMSY_ekqAutoList15I.I.I.I.I.I.I.I.  $USUS.,2XcXXX `   30    _Inaddition,AppendixEoftheJune2,2003proposal  treats1hour_NSR_Ԁasanapplicablerequirementafterthe1  hourstandardisrevoked.Underthefinalrule,1hour_NSR_ \ wouldnotbearequiredimplementationplanelementafter 2 the1hourstandardisrevoked.Instead,_NSR_Ԁunderthe8 X hour_NAAQS_Ԁwillapply.3i)&c$""0 3i)(hCEKQW]cioAutoList61.1.1.1.1.1.1.1.g1.(hCEKQW]cioAutoList71.1.1.1.1.1.1.1.i1.3i)A@%2A`Helv $USUS.,2XcXXX `   33    _Opcit.  $USUS.,2XcXXX `   19    _Theseincludetryingtomeetthefollowingobjectives  asdiscussedabove:(a)providingflexibilityin  determiningthemosteffectivecontrol;(b)achieving \ attainmentatcostslowerthanthoseforstrategieswith 2 prescribedmeasures;(c)providingflexibilityinaddressing X nonattainmentareasthatarehavedifficultyattainingdue . totransport;and(d)ensuringexpeditiousbutreasonable   attainmentdates.bI. ##CXd#(hCEKQW]cioAutoList8a.a.a.a.a.a.a.a.|a.(hCEKQW]cioAutoList9a.a.a.a.a.a.a.a.a.  $USUS.,2XcXXX `   9    _Similarly,AlternativesAandBwouldresultinfewer  areasbeingplacedundersubpart1.(See68FR60060,Table  2.October21,2003).      p    TTRY,3' LetterP('3 Letter Landscape 3' Letter'3 Letter LandscapeTTable_A(գEGMSY_ekqAutoList10a.a.a.a.a.a.a.a.a.(EGMSY_ekqAutoList111.1.1.1.1.1.1.1.1.(EGMSY_ekqAutoList12a.a.a.a.a.a.a.a.a.Level 1Level 2Level 3Level 4Level 5Level 1Level 2Level 3Level 4Level 5Level 1Level 2Level 3Level 4Level 5Level 1Level 2Level 3Level 4Level 5Level 1Level 2Level 3Level 4Level 5&Draw Object =8C HKKKKLevel 1Level 2Level 3Level 4Level 5&OLE 2.0 Box <=8C HKKKK(.3$ !USUS.,  ]]]])!dxdx)!dxdx( $ Figure  1  (.3$ !USUS.,  E<<C($$   1  (EGMSY_ekqAutoList14a.a.a.a.a.a.a.a.a.3i)http://www.epa.gov/edocket3i)A@3i)3i)3i)3i)<6X9`(Courier New1. ! $USUS.,2XcXXX `   6    _ԀThedesignvalueofanareaisbasedonthemonitor  forthearearecordingthehighestozonelevelsand  indicateswhethertheareaisviolatingormeetingtheozone \ NAAQS.Forthe1hourozoneNAAQS,thedesignvalueforan 2 areaisgenerallythe4thhighestmonitoredozonelevelat X themonitorovera3yearperiod.See40CFRpart50, . appendixHandMemorandumofJune18,1990fromWilliamG.   _Laxton_Ԁre OzoneandCarbonMonoxideDesignValue   Calculations.Availableat `  4 O  5  http://www.epa.gov/ttn/naaqs/ozone/ozonetech/laxton.htm6VOj  7 Ԁ. 6   Forthe8hourozoneNAAQS,thedesignvalueistheaverage  \  ofeachyearly4thhighestreadingatamonitorovera3  2  yearperiod.See40CFRpart50,appendixI. ] $USUS.,2XcXXX `   7    _Thenoticealsosolicitedcommentonadditionalissues  thatwouldariseifweselectedoneoftheapproaches  identifiedinthenoticereopeningthecommentperiod:1) \ whetherweshouldmodifythe5percentreclassification 2 featureofsection181(a)(4)oftheCAAifwechangeour X classificationschemetohaveanarrowerrangeforeach . classification;2)whetherweshouldadoptthesuggestion   bycommentersontheJune2,2003proposalthatwechange   the1hourozonethresholdto0.125ppmratherthan0.121 `  ppmtodetermineifanareafallsintosubpart1vs.subpart 6   2underclassificationOption2;and3)whetheran  \  adjustmentotherthan50percentwouldbemoreappropriate  2  fornarrowingtherangeofeachclassification. \ $USUS.,2XcXXX `   8    _ԀInthePhase2rule,wewilladdressthecontrol_and  planningobligations_Ԁthatapplytoareasunderbothsubpart  1andsubpart2. ' $USUS.,2XcXXX `   12    _Forinstance,thecostofselectivecatalytic  reduction(SCR)catalyst(forcontrolofNOx)_has_Ԁgonefrom  $11,000-$14,000/cubicmeterin1998to$3,500- \ $5,500/cubicmetercurrently.AdvancementsinlowNOx 2 burner(LNB)technologyandstagedcombustionhaveresulted X insharpNOxreductionsatmuchlowercosts.Newburner . technologieshaveloweredNOxemissionsreductionsbyas   muchas50percentfrompreviousdesigns.Costshave   decreasedfrom$25-38/kWin1993toabout$15/kWin2003. `  MemorandumofOctober10,2003fromJimStaudt,Andover 6   TechnologyPartners,Re:PrimeContract68W03028;  \  SubcontractAgreement23BL00114;ATPContract#:C03007.  $USUS.,2XcXXX `   13    _REVISED:BackgroundInformationDocument,  HypotheticalNonattainmentAreasforPurposesof  UnderstandingtheEPAProposedRuleforImplementingthe \ 8-hourOzoneNationalAmbientAirQualityStandardin 2 RelationtoRe-OpenedCommentPeriod--Illustrative X AnalysisBasedon2000-2002Data.U.S.Environmental . ProtectionAgency,OfficeofAirandRadiation,Officeof   AirQualityPlanningandStandards.Draft.October2003.   Availableat:http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.  $USUS.,2XcXXX `   14    _Theseareasincluded:(a)thef  g f  g transitionalf  g Ԁareas  undersection185A(areasthatweredesignatedasanozone  nonattainmentareaasofthedateofenactmentoftheCAA \ Amendmentsof1990butthatdidnotviolatethe1hourozone 2 NAAQSbetweenJanuary1,1987,andDecember31,1989);(b) X nonattainmentareasthathadincomplete(orno)recent . attainingdataandthereforecouldnotbedesignated   attainment;and(c)areasthatwereviolatingthe1hour   ozoneNAAQSbyvirtueoftheirexpectednumberof `  exceedances,butwhosedesignvalueswerelowerthanthe 6   thresholdforwhichanareacanbeclassifiedunderTable1  \  ofsubpart2(f  g f  g submarginalf  g Ԁareas).See57FR13498at13524  2  col.3etseq.(April16,1992).  $USUS.,2XcXXX `   15    _Seealso:BackgroundInformationDocument,  HypotheticalNonattainmentAreasforPurposesof  UnderstandingtheEPAProposedRuleforImplementinghe \  8-hourOzoneNationalAmbientAirQualityStandard.  IllustrativeAnalysisBasedon1998!2000Data.U.S.  EnvironmentalProtectionAgency,OfficeofAirand \ Radiation,OfficeofAirQualityPlanningandStandards, 2 Draft,April2003.Availableat: X http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.  $USUS.,2XcXXX `   17    _BackgroundInformationDocument,Hypothetical  NonattainmentAreasforPurposesofUnderstandingtheEPA  ProposedRuleforImplementingthe8-hourOzoneNational \ AmbientAirQualityStandard.IllustrativeAnalysisBased 2 on1998!2000Data.U.S.EnvironmentalProtectionAgency, X OfficeofAirandRadiation,OfficeofAirQualityPlanning . andStandards,Draft,April2003.Availableat:   http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/. F $USUS.,2XcXXX `   18    _ԀConcernabouttransportissupportedbyEPAs  modelingfortheInterstateAirQualityRule(69FR4566,  January30,2004);EPAhasproposedtofindthatinthe \ absenceoffurthercontrols,25Stateswouldsignificantly 2 contributetodownwindnonattainmentinotherStatesin X 2010,evenaftertheNOxSIPCallhasbeeninfulleffect. . Asaresult,EPAhasproposedtorequirethe25Statesto   reducetheiremissionsofNOxtoreduceinterstate   transport,withthereductionstobeachievedby2010and `  2015. T $USUS.,2XcXXX `   21    _Basedondatafrom:REVISED:BackgroundInformation  Document,Hypothetical_Nonattainment_ԀAreasforPurposesof  UnderstandingtheEPAProposedRuleforImplementingthe \ 8-hourOzoneNationalAmbientAirQualityStandardin 2 RelationtoRe-OpenedCommentPeriod--Illustrative X  AnalysisBasedon2000-2002Data.U.S.Environmental  ProtectionAgency,OfficeofAirandRadiation,Officeof  AirQualityPlanningandStandards.Draft.October2003. \ Availableat:http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.  $USUS.,2XcXXX `   22    _ԀAsprovidedbelow,inthesectionregarding  attainmentdatesforthe8hourozoneNAAQS,subpart2  actuallyspecifiesthattheattainmentperiodrunsfromthe \ dateofthe1990CAAAmendmentsratherthanthedateof 2 designation.However,asweexplainintheattainmentdate X section,forpurposesof8hourNAAQS,webelieveCongress . intendedthosedatestorunfromthedateofdesignation.  $USUS.,2XcXXX `   23    _ԀTheonlycontrolobligationsmandatedformarginal  areasarethattheyfixflawsintheirRACTrulesandtheir  I/Mprogramsthatexistedatthetimeofthe1990CAA \ Amendments.Areasdesignatednonattainmentforthe1hour 2 NAAQS,whichweretheareaswiththepre90RACTandI/M X obligations,havealreadymadethesecorrections.Itis . unlikelythatanyareasdesignatednonattainmentforthe8   hourNAAQSwillnothavealreadymadethesecorrectionsif   theyhavesuchprogramsinplace. $USUS.,2XcXXX `   24    _See68FR32814.3i)g1.i1.3i)3i)A@bI.|a.a.a.1.a.a.3i)3i)3i)1.(EEGOW_gowAutoList13(a)(a)(a)(a)(a)(a)(a)(a)(a)3i)(a)3i)  $USUS.,2XcXXX `   11    _QualitativeAssessmentofAlternativeCoverageand  ClassificationOptions.FirstAddendumto Cost,Emission  Reduction,Energy,andEconomicImpactAssessmentofthe \ ProposedRuleEstablishingtheImplementationFrameworkfor 2 the8-hour,0.08ppmOzoneNationalAmbientAirQuality X Standard.PreparedbyInnovativeStrategiesandEconomics . Group,AirQualityStrategiesandStandardsDivision,Office   ofAirQualityPlanningandStandards,OfficeofAirand   Radiation,U.S.EnvironmentalProtectionAgency,Research `  TrianglePark,NorthCarolina.April8,2004.http://www.epa.gov/ttn/naaqs/ozone/ozonetech/laxton.htm(.3$ !USUS.,   P $USUS.,2XcXXX `   20    _Basedondatafrom:REVISED:BackgroundInformation  Document,Hypothetical_Nonattainment_ԀAreasforPurposesof  UnderstandingtheEPAProposedRuleforImplementingthe \ 8-hourOzoneNationalAmbientAirQualityStandardin 2 RelationtoRe-OpenedCommentPeriod--Illustrative X AnalysisBasedon2000-2002Data.U.S.Environmental . ProtectionAgency,OfficeofAirandRadiation,Officeof   AirQualityPlanningandStandards.Draft.October2003.   Availableat:http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr/.  $USUS.,2XcXXX `   10    _REVISED:BackgroundInformationDocument,  HypotheticalNonattainmentAreasforPurposesof  UnderstandingtheEPAProposedRuleforImplementingthe8 \ HourOzoneNationalAmbientAirQualityStandardinRelation 2 toReOpenedCommentPeriod!IllustrativeAnalysisBasedon X 20002002Data.U.S.EnvironmentalProtectionAgency, . OfficeofAirandRadiation,OfficeofAirQualityPlanning   andStandards.Draft.October2003.Availableat:   4 O  5  http://www.epa.gov/ttn/naaqs/ozone,o3imp8hr/.6O  7 1Ԁhttp://www.epa.gov/ttn/naaqs/ozone,o3imp8hr/. w $USUS.,2XcXXX `   16    _Forinstance,therangeof1hourozonedesignvalues  ofthehypotheticalsubpart1areasisfrom0.101ppmto  0.120ppm,withanaverageof0.111ppm.Therangeof1 \ hourdesignvaluesofsubpart2areasisfrom0.122ppmto 2  0.175ppmwithanaverageof0.133ppm.Seedocketdocument  OAR-2003-0079-0573(REVISED:BackgroundInformation  Document,HypotheticalNonattainmentAreasforPurposesof \ UnderstandingtheEPAProposedRuleforImplementingthe 2 8-hourOzoneNAAQSinRelationtoRe-OpenedCommentPeriod) X forthedatausedforthesestatistics. < $USUS.,2XcXXX `   25    _MemorandumofMay10,1995, RFP,Attainment  Demonstration,andRelatedRequirementsforOzone  NonattainmentAreasMeetingtheOzoneNationalAmbientAir \ QualityStandard,fromJohnS.Seitz,Director,Officeof 2 AirQualityPlanningandStandards.Availableat: X http://www.epa.gov/ttn/oarpg/t1/memoranda/clean15.pdf.  $USUS.,2XcXXX `   26    _Asexplainedinourproposedrule,areaswillbe  classifiedasamatteroflawatthesametimetheyare  designated;thus,wesimplyreferto designationrather \ thandesignationandclassification. 8 $USUS.,2XcXXX `   27    _The1hourNAAQS,anexceedancebasedNAAQS,is  basicallyallowedtobeexceededanaverageofonlyoncea  yearovera_3__year_Ԁperiod.(Thisisageneralizationofhow \  attainmentisdetermined;theactualmethodconsidersother  factorssuchascompletenessofthedata.)See40_CFR,_  _appendix_ԀH.Incontrast,thelevelofthe8hourNAAQS \ (0.08ppm,8houraverage)canbe exceededmorethanonce 2 ayearonaveragebecausetheform(concentrationbased)of X thatNAAQSisdeterminedbyaveragingthe4thhighreading . foreachyearovera_3_yearperiod.Section50.10(b)   providesthatthe8hourNAAQSismetatanambientair   qualitymonitorwhentheaverageoftheannualfourth `  highestdailymaximum8houraverageozoneconcentrationis 6   lessthanorequalto0.08ppm.40CFR_part_Ԁ50,_appendix_ԀI.  \  Example1in_appendix_ԀIprovidesanexampleofanambient  2  monitoringsiteattainingthe8hourozoneNAAQS.The   exampleshowsthatovera3yearperiod,therewere10   exceedancesofthelevelofthe8hourozoneNAAQS,oran d  averageof3.33exceedancesperyear.  $USUS.,2XcXXX `   28    _ԀInaddition,inJune2003,westayedourauthority  toapplytherevocationrulependingourreconsiderationin  thisrulemakingofthebasisforrevocation._(68_ԀFR_38160,_ \  June26,_2003)._ p $USUS.,2XcXXX `   29    _Thedraftregulatorytextdidnotaccuratelyreflect  thepreamblediscussionwhichdistinguishedmaintenance  areasatthetimeofdesignationforthe8hourNAAQSfrom \ thosethatremaineddesignatednonattainmentatthetimeof 2 8hourdesignation.Forthefinalrule,weusethetimeof X 8hourdesignationsratherthanthetimethe1hourNAAQSis . revoked.  $USUS.,2XcXXX `   31    _ԀForpurposesofthepreambletothisrulemaking,  wheneverwestatethataStatemustmakethedemonstration  requiredundersection110(l)tomodifyitsSIP,wealso \ meanthattheStatemustmaketherequireddemonstration 2 undersection193totheextenttheaffectedareais X designatednonattainmentandtheSIPrequirementtheState . ismodifyingwasacontrolrequirementineffectorrequired   tobeineffectpriortoNovember15,1990.  $USUS.,2XcXXX `   32    _ԀInthisrulemaking,weuse ROPtorefertothe  rateofprogressrequirementforthe1hourNAAQSand RFP  torefertoboththerateofprogressrequirementunder \ subpart2andthereasonablefurtherprogressrequirement 2 undersubpart1forthe8hourozoneNAAQS.(CEMU]emu}AutoList5(1)(1)(1)(1)(1)(1)(1)(1) . $USUS.,2XcXXX `   34    _Theamountofwhichwill_depend_ԀontheROPoptionin  thefinalruleandtheclassificationofthearea. < $USUS.,2XcXXX `   35    _MemorandumofMay10,1995, RFP,Attainment  Demonstration,andRelatedRequirementsforOzone  NonattainmentAreasMeetingtheOzoneNationalAmbientAir \ QualityStandard,fromJohnS.Seitz,Director,Officeof 2 AirQualityPlanningandStandards.Availableat: X http://www.epa.gov/ttn/oarpg/t1/memoranda/clean15.pdf. y $USUS.,2XcXXX `   36    _Inordertoredesignatetheseareastoattainment,  EPAhadtodeterminetheseareashadmetallobligations  under_part_ԀD.SeeCAASection107(d)(3)(E). ) $USUS.,2XcXXX `   37    _ԀIfanarealocatedintheOzoneTransportRegionwas  redesignatedtoattainment,section184(b)(2)oftheCAA  requiredittoretainanonattainmentNSRprogram.In \ addition,itispossiblethatoneormoreareasstillhasa 2 nonattainmentNSRprograminplacebecauseofthewaythe X StatewrotetheSIP. Z $USUS.,2XcXXX `   38    _PXcXX2XcThesetwooptionswere:1)whentheareaattainsthe  1hourNAAQS,or(2)whentheareaattainsthe8hourNAAQS.#2XcXXPXc#3i)3i)A@3i)3i)g1.i1.3i)A@bI.|a.a.a.1.a.a.3i)3i)3i)1.3i)(a)3i)3i) / $USUS.,2XcXXX `   4    _ԀInthePhase2rule,wewilladdressthecontrol  obligationsthatapplytoareasunderbothsubpart1and  subpart2.<4 9Z+.Courier New Regular ( $USUS.,2XcXXX `   39    _IfanarealocatedintheOzoneTransportRegionwas  redesignatedtoattainment,section184(b)(2)oftheCAA  requiredittoretainanonattainmentNSRprogram.In \ addition,itispossiblethatoneormoreareasstillhasa 2 nonattainmentNSRprograminplacebecauseofthewaythe X StatewrotetheSIP.  $USUS.,2XcXXX `   40    _MemorandumfromMaryNicholstoRegionalAirDivision  DirectorsdatedOctober14,1994,entitled PartDNew  SourceReview(partDNSR)RequirementsforAreasRequesting \ RedesignationtoAttainment.  $USUS.,2XcXXX `   41    _Wediscusstheobligationfortheseareastoadopta  section110(a)(1)maintenanceplanbelow.  $USUS.,2XcXXX `   42    _ԀPartDNewSourceReview(partD_NSR_)Requirements  forAreasRequesting_Redesignation_ԀtoAttainment,October  14,1994,fromMaryD._Nichols_.  $USUS.,2XcXXX `   43    _WhenEPApromulgatedtheNOxSIPCall,werequired  thesamelevelofreductionsforboththe1hourand8hour  ozoneNAAQS(63FR57356,October27,1998).Inresponseto \ theCourtofAppealsremandofthe8hourNAAQS,EPAstayed 2 the8hourbasisoftheNOxSIPCall(65FR2674,January X 18,2000).However,sincethesamelevelofreductionswas . requiredforboththe8hourand1hourNAAQS,thestayhad   nopracticaleffectonStatescompliancewiththerule.    BecauseEPAalsostayedthe8hourportionoftheSection `  126Rule,wedidnotmoveforwardtomakethesection126 6   findingsunderthe8hourNAAQSwhichwouldtriggerthe8  \  hourcontrolrequirements(65FR2674,January18,2000).  2  Weplantocompleterulemakingactiononthe8hour   petitionsatthetimeweliftthe8hourstay.Allofthe   Statesaffectedbythe1hourand/or8hourSection126Rule d  arealsocoveredbytheNOxSIPCall.TheSection126Rule :  containsaprovisionunderwhichtheSection126findings `  andcontrolrequirementswouldbewithdrawnifStateshave 6 approvedSIPsmeetingtheNOxSIPCall.TheEPAhasalready   withdrawnthe1hourSection126Rulein_three_ԀStatesand  theDistrictofColumbiaandproposedtowithdrawthe1hour h ruleinallotheraffectedStatesexceptone.(Weexpectto > proposeactionwithrespecttotheruleintheremaining d  Stateshortly.)   $USUS.,2XcXXX `   44    _ԀAsdiscussedinthesectionregardingthetwo1year  attainmentdateextensions,section172(a)(2)(C),which  appliestoallpollutants,allowsfora1yearattainment \ dateextensioniftheareahashad minimalexceedancesin 2 theattainmentyearandsection181(a)(5),whichappliesto X ozonenonattainmentareasclassifiedundersubpart2,allows . fora1yearextensioniftheareahashadnomorethan1   exceedanceintheattainmentyear.  $USUS.,2XcXXX `   45    _Memorandum,GuidanceontheReasonablyAvailable  ControlMeasures(RACM)RequirementandAttainment  DemonstrationSubmissionsforOzoneNonattainmentAreas. \ JohnS.Seitz,Director,OfficeofAirQualityPlanningand 2 Standards.November30,1999.website: X 4` O  5  http://www.epa.gov/ttn/oarpg/t1pgm.html6 O   7 PK.http://www.epa.gov/ttn/oarpg/  $USUS.,2XcXXX `   46    _EPAissuedthememorandum BoundaryGuidanceonAir  QualityDesignationsforthe8HourOzoneNationalAmbient  AirQualityStandard(NAAQSorStandard)onMarch28,2000, \ fromJohnS.Seitz,Director,OfficeofAirQualityPlanning 2 andStandards,totheAirDirectors,RegionsIX,toprovide X guidancetoStateandlocalagenciesandTribeson . designatingareasandEPAsviewsonboundariesfor   nonattainmentareasforthe8hourNAAQS. 7 $USUS.,2XcXXX `   47    _OAR-2003-0079-0081,0085AmericanPetroleumInstitute  (API)requestsforextensiontotheAugust1st,2003comment  deadline.  $USUS.,2XcXXX `   48    _OAR-2003-0079-0405RequestforExtensionofTimefor  FilingCommentsonDraftRegulatoryTextforProposedRule  toImplementthe8-HourOzoneNationalAmbientAirQuality \ Standard(NAAQS)submittedbyHowardJ.Feldman,Director, 2 AmericanPetroleumInstitute. Q $USUS.,2XcXXX `   49    _OAR-2003-0079-0542,0589,0590RequestforExtension  oftimefor15-daycommentperiodonapproachestoimplement  the8-hourozoneNAAQS,submittedbyGregoryDana,Vice \ PresidentEnvironmentalAffairs,AllianceofAutomobile 2 Manufacturers. X OAR-2003-0079-0555Requestforextensionoftimefor15-day   commentperiodonalternativeapproachestoimplementthe   8-hourozoneNAAQSsubmittedbyHowardFeldman,Director `  RegulatoryAnalysisandScientificAffairs,American 6   PetroleumInstitute(API).  \  OAR-2003-0079-0572RequestforExtensionofPublicComment   PeriodsubmittedbyLeslieS.Ritts,CounseltoTheNational   EnvironmentalDevelopmentAssociationsCleanAirRegulatory d  Project(NEDA/CARP). J $USUS.,2XcXXX `   50    _See,forinstance,OAR-2003-0079-0165LetterfromS.  Page,Director,OAQPStoH.J.Feldman,Director,API,  denyingextensionofcommentperiod. I'USUS.,  _ `    ӀRuletoImplementthe8HourOzoneStandard  Page___of___ !USUS.,  _f @ g 8cXXdd8  f  g z{d USUS.,2XcXXX `   0        ӀԀ XcXX2Xc656050P  v  ENVIRONMENTALPROTECTIONAGENCY ` 40_CFR_Ԁ_Parts_Ԁ_50,51AND81 _____ ( x  [OAR20030079,FRL_]   @ __RIN_     FinalRuletoImplementthe8HourOzoneNationalAmbient d  AirQualityStandard!Phase1  ,|   AGENCY: EnvironmentalProtectionAgency(EPA). D   ACTION: _Final_Ԁ_rule_.    _SUMMARY_: Inthisdocument,EPAistakingfinalactiononkey  elementsoftheprogramtoimplementthe8hourozone L nationalambientairqualitystandard(_NAAQS_Ԁorstandard). H Thisfinalruleaddressesthefollowingtopics:  classificationsforthe8hour_NAAQS_;revocationofthe1 P hour_NAAQS_Ԁ(i.e.,whenthe1hour_NAAQS_Ԁwillnolonger L apply);howantibackslidingprincipleswillensure   continuedprogresstowardattainmentofthe8hourozone T!" _NAAQS_;attainmentdates;andthetimingofemissions #P$ reductionsneededforattainment.Weareissuingthisrule $& sothatStatesandTribeswillknowhowweplantoclassify X&!( areasandtransitionfromimplementationofthe1hour_NAAQS_ (T#* toimplementationofthe8hour_NAAQS_.Theintendedeffect )%, oftheruleistoprovidecertaintytoStatesandTribes \+&. regardingclassificationsforthe8hour_NAAQS_Ԁandtheir -X(0 z{d z8cXXdXXd8 z  _continuedobligationswithrespecttoexistingrequirements.   ` ThisdocumentisPhase1oftheprogramtoimplement \ the8hourozone_NAAQS_.Weplantoissueasecondrule, X Phase2,withinthenextseveralmonthswhichwilladdress   theremaining8hourimplementationissues,e.g., `  requirementsforreasonablefurtherprogress(_RFP_),  \  requirementsformodelingandattainmentdemonstrations,and   requirementsforreasonablyavailablecontrolmeasures d  (_RACM_)andreasonablyavailablecontroltechnology(_RACT_). `   EFFECTIVEDATE: ThisruleiseffectiveonJune15,2004.    ADDRESSES: TheEPAhasestablishedadocketforthisaction  underDocketIDNo.OAR20030079.Alldocumentsintf  g he L docketf  arelistedinthe_EDOCKET_Ԁindexat H 4 O  5  http://www.epa.gov/edocket6O  7 8.Althoughlistedintheindex,  someinformationisnotpubliclyavailable,i.e., P ConfidentialBusinessInformationorotherinformationwhose L disclosureisrestrictedbystatute.g Certainother   material,suchascopyrightedmaterial,isnotplacedonthe T!" Internetandwillbepubliclyavailableonlyinhardcopy #P$ form.Pf  g ubliclyavailabledocketmaterialsareavailable $& eitherelectronicallyin_EDOCKET_ԀorinhardcopyattheEPA X&!( DocketCenter(AirDocket),EPA/DC,EPAWest,RoomB102, (T#* 1301ConstitutionAve.,NW,Washington,DC.ThePublic )%, ReadingRoomisopenfrom8:30a.m.to4:30p.m.,Monday \+&. throughFriday,excludinglegalholidays.Thetelephone  _numberforthePublicReadingRoomis(202)5661744,and \ thetelephonenumberfortheOfficeofAirandRadiation X DocketandInformationCenteris(202)5661742.    ` Inaddition,wehaveplacedavarietyofearlier `  materialsregardingimplementationofthe8hourozoneNAAQS  \  onthewebsite:   4 O  5  http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr.6 O  7 KԀ d   FORFURTHERINFORMATIONCONTACT: Mr.JohnSilvasi,Officeof `  AirQualityPlanningandStandards,U.S.Environmental ( ProtectionAgency,MailCodeC53902,ResearchTriangle  Park,NC27711,phonenumber(919)54l5666,faxnumber 0 (919)54l0824orbyemailat4 O  5  silvasi.john@epa.gov6IO]  7 ԀorMs. , DeniseGerth,OfficeofAirQualityPlanningandStandards,  U.S.EnvironmentalProtectionAgency,MailCodeC53902, 4 ResearchTrianglePark,NC27711,phonenumber(919)54l 0 5550,faxnumber(919)54l0824orbyemailat   4 O  5  gerth.denise@epa.gov.6MOa  7 Ԁ 8!"  SUPPLEMENTARYINFORMATION:  "4$  Outline  $& I.WhenDidEPAProposethisRule? t&!( II.WhatisEPAsScheduleforTakingFinalActiononthe  (p#* Proposal? )%, III.WhatisIncludedinthisRule? x+&. IV.InShort,whatdoesthisFinalRuleContain?  A.g HowwillEPAreconciletheclassificationprovisionsof \ subparts1and2?HowwillEPAclassifynonattainmentareas X forthe8hourstandard?   B. ` HowwillEPAtreatattainmentdatesforthe8Hour `  ozonestandard?  \  C.HowwillEPAimplementthetransitionfromthe1hourto   the8hourstandardinawaytoensurecontinuedmomef  nf  g tumin d  Stateseffortstowardcleanerair? `  2XcXX XcD.Whatistherequiredtimeframeforobtainingemissions   reductionstoensureattainmentbytheattainmentdate?# XcXX2Xc# h V.EPAsFinalRule d A.g HowwillEPAreconciletheclassificationprovisionsof  subparts1and2?HowwillEPAclassifynonattainmentareas l forthe8hourNAAQS? h 0 ` 1.Background` (#` (# 0 ` 0 ` (#` (#a.f  g f  g StatutoryframeworkandSupremeCourtdecision.p  (# (# 2XcXX Xc0 ` 0 ` (#` (#b.EPAsproposedruleandnoticereopeningthe !l" commentperiod."$ (# (# 0 ` 2.Summaryoffinalrulet$&` (#` (# # XcXX2Xc!#2XcXX Xc0 ` 0 ` (#` (#a.WhydidEPAselectOption2? &p!( (# (# 0 ` 0 ` (#` (#0 (# (#(i)WhywillOption2bestaccomplishthe '#* policygoalsofEPA?# XcXX2Xc"#2XcXX Xcx)$,(#(# 0 ` 0 ` (#` (#0 (# (#(ii)HowisOption2ConsistentwiththeCAA $+t&. asInterpretedbytheSupremeCourt?# XcXX2Xc##2XcXX Xc(#(# 0 ` 3. CommentsandResponses\` (#` (# # XcXX2Xc$#0 ` 4. Underthefinalclassificationapproach,howwill X EPAclassifysubpart1areas? ` (#` (#  (գ8330 ` 0 ` (#` (#a.Background.`  (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule.2XcXX Xc \  (# (# 0 ` 0 ` (#` (#c.CommentsandResponses      (# (# # XcXX2Xc?'#2XcXX Xc0 ` 5. WillEPAadjustclassifications?d ` (#` (# 0 ` 0 ` (#` (#a.Background.`  (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule.  (# (# 0 ` 0 ` (#` (#c.CommentsandResponsesh (# (# # XcXX2Xc(#2XcXX Xc0 ` 6.ProposedIncentiveFeatured` (#` (# 0 ` 0 ` (#` (#a.Background.# XcXX2Xc)#2XcXX Xc (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule.l (# (# 0 ` 0 ` (#` (#c.CommentsandResponses    h (# (# # XcXX2Xcp*#B. ` HowwillEPAtreatattainmentdatesforthe8hour  ozoneNAAQS? p  0 ` 1. Background.!l"` (#` (# 0 ` 2.Summaryoffinalrule."$` (#` (# 0 ` 3. CommentsandResponset$&` (#` (# 0 ` 4.HowWillEPAAddresstheProvisionRegarding1  &p!( YearExtensions?'#*` (#` (#  (880 ` 0 ` (#` (#a.Background.x)$, (# (# 0 ` 0 ` (#` (#b.  Summaryoffinalrule.$+t&. (# (# 0 ` 0 ` (#` (#c.CommentsandResponse (# (# C.HowwillEPAimplementthetransitionfromthe1hourto \ the8hourNAAQSinawaytoensurecontinuedmomef  nf  g tumin X Stateseffortstowardcleanerair?   2XcXX Xc0 ` 1.f  g f  g f  g f  g WhenwillEPArevokef  g Ԁthe1hourstandard?# XcXX2Xc/#` ` (#` (# 0 ` 0 ` (#` (#a.Background. \  (# (# 2XcXX Xc0 ` 0 ` (#` (#b.SummaryofFinalRule.# XcXX2XcR1#2XcXX Xc  (# (# 0 ` 0 ` (#` (#c.0 (# (#CommentsandResponsesd (#(# # XcXX2Xc1#2XcXX Xc0 ` # XcXX2Xc2#2.Whatrequirementsthatappliedinanareaforthe `  1hourNAAQScontinuetoapplyafterrevocationofthe   1hourNAAQSforthatarea?h` (#` (# 0 ` 0 ` (#` (#a.Background.d (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule. (# (# 0 ` 0 ` (#` (#c.Section51.905(a)(1):8HourNAAQS l Nonattainment/1HourNAAQSNonattainmenth (# (# 0 ` 0 ` (#` (#0 (# (#(i)MandatoryControlMeasures.(#(# 0 ` 0 ` (#` (#  (ii)Discretionarycontrolmeasuresp  (# (# 0 ` 2XcXX Xc0 ` (#` (#  (iii)Measurestoaddressgrowth.!l" (# (# 0 ` # XcXX2Xc5#2XcXX Xc0 ` (#` (#  (iv)f  g f  g PlanningSIPsf  g f  g .f  g "$ (# (# f  g 0 ` # XcXX2Xc6#0 ` (#` (#d.Section51.905(a)(2):8HourNAAQS t$& Nonattainment/1HourNAAQSMaintenance &p!( (# (# 0 ` 0 ` (#` (#  (i)MandatoryControlMeasures.'#* (# (# 0 ` 0 ` (#` (#0 (# (#(ii)DiscretionaryControlmeasuresx)$,(#(# 0 ` 0 ` (#` (#  (iii)Measurestoaddressgrowth.$+t&. (# (# 0 ` 0 ` (#` (#  (iv)PlanningSIPs. (# (# 0 ` 0 ` (#` (#e.Section51.905(a)(3):8HourNAAQSAttainment \ /1HourNAAQSNonattainmentX (# (# 0 ` 0 ` (#` (#  (i)Mandatorycontrolobligations.  (# (# 0 ` 0 ` (#` (#  (ii)Discretionarycontrolobligations.`  (# (# 0 ` 0 ` (#` (#  (iii)Measurestoaddressgrowth. \  (# (#  (880 ` 0 ` (#` (#  (iv)PlanningSIPs.  (# (# 0 ` 0 ` (#` (#0 (# (#(v)MaintenancePlansforthe8hourNAAQS.d (#(# 0 ` 2XcXX Xc0 ` (#` (#f.# XcXX2Xce=#Section51.905(a)(4):8HourNAAQS `  Attainment/1HourNAAQSMaintenance  (# (# 0 ` 0 ` (#` (#  (i)ObligationsinanapprovedSIP.h (# (# 0 ` 0 ` (#` (#  (ii)Maintenanceplan.d (# (# 0 ` 3.Forhowlongdotheseobligationscontinueto  apply?l` (#` (# 0 ` 0 ` (#` (#a.Background.h (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule. (# (# 0 ` 0 ` (#` (#c.CommentsandResponsesp  (# (# 0 ` 4.Whichportionsofanareadesignatedforthe8hour !l" NAAQSremainsubjecttothe1hourNAAQSobligations?"$` (#` (# 0 ` 0 ` (#` (#a.Background.t$& (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule. &p!( (# (# 2XcXX Xc0 ` 0 ` (#` (#c.CommentsandResponses'#* (# (# # XcXX2XcA#2XcXX Xc0 ` 5.Whatobligationsthatappliedforthe1hourNAAQS x)$, willnolongerapplyafterrevocationofthe1hour $+t&. NAAQSforanarea?` (#` (# 0 ` 0 ` (#` (#a.Background\ (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRuleX (# (# # XcXX2XcuB#2XcXX Xc0 ` 0 ` (#` (#c.CommentsandResponses  (# (# 0 ` 0 ` (#` (#0 (# (#(i)CommentsonJune2,2003proposal:` (#(# 0 ` 0 ` (#` (#  # XcXX2Xc-D#(ii)Commentsondraftregulatorytext \  (# (# 2XcXX Xc0 ` 6.WhatisthecontinuedapplicabilityoftheNOxSIP   Callafterrevocationofthe1hourNAAQS?d ` (#` (# 0 ` 0 ` (#` (#a.Background`  (# (# 0 ` 0 ` (#` (#b.SummaryofFinalRule  (# (# 0 ` 0 ` (#` (#c.CommentsandResponsesh (# (# 0 ` 0 ` (#` (#0 (# (#(i)CommentsontheJune2,2003proposal:d(#(# # XcXX2XcE#2XcXX XcD.Whatistherequiredtimeframeforobtainingemissions  reductionstoensureattainmentbytheattainmentdate? l 0 ` 1. Background.h` (#` (# # XcXX2XcH#0 ` 2. Summaryoffinalrule.` (#` (# 0 ` 3. CommentsandResponsesp ` (#` (# E.ConformityUnderthe8HourOzoneStandard !l" F.CommentsonOtherIssues "$ 0 ` 1. Designationsofnonattainmentandattainment t$& areas: &p!(` (#` (# 0 ` 2. EarlyActionCompacts(EACs):'#*` (#` (# 0 ` 3. Healthandenvironmentalconcerns:x)$,` (#` (# 0 ` 4. Clarityandunderstandabilityofproposedrule:$+t&.` (#` (# 0 ` 5. Regulatorytext:` (#` (# 0 ` 6.RequestsforExtensionofCommentPeriods:\` (#` (# G.OtherConsiderations X 0 ` 1.WhathappensifasourceisintheprocessofPSD   permittingatthetimethattheareainwhichitis `  locatedisdesignatedasnonattainmentforthe8hour  \  ozonestandard? ` (#` (# H.EPAsFinalAction d  VI.STATUTORYANDEXECUTIVEORDERREVIEWS `  A.ExecutiveOrder12866:RegulatoryPlanningandReview   B.PaperworkReductionAct h C.RegulatoryFlexibilityAct d D.UnfundedMandatesReformAct  E.ExecutiveOrder13132:Federalism l F.ExecutiveOrder13175:ConsultationandCoordination h withIndianTribalGovernments  G.ExecutiveOrder13045:ProtectionofChildrenfrom p  EnvironmentalHealthandSafetyRisks !l" H.ExecutiveOrder13211:ActionsThatSignificantlyAffect "$ EnergySupply,Distribution,orUse t$& I.NationalTechnologyTransferAdvancementAct  &p!( J.ExecutiveOrder12898:FederalActionstoAddress '#* EnvironmentalJusticeinMinorityPopulationsandLowIncome x)$, Populations $+t&. K.CongressionalReviewAct   I.WhenDidEPAProposethisRule?  \  ` OnJune2,2003(68FR32805),wepublishedaproposed $t ruletoimplementthe8hourozoneNAAQS.Theproposal   addressedanumberofimplementationissues,includingthe |  twocoreimplementationissuesaddressedinthisfinalrule, ( x  e.g.,howtheCleanAirAct(CAAorAct)classification $  provisionswillapplyforthe8hourozoneNAAQSandthe   transitionfromthe1hourNAAQStothe8hourNAAQS, ,|  includingwhenthe1hourNAAQSwillberevokedandanti ( backslidingprinciples.Weproposedoneormoreoptionsfor  eachissueaddressedintheproposal.Inaddition,we 0 includedtwopossibleframeworkstoimplementthe8hour , ozoneNAAQS.Theseframeworkswerecompleteimplementation  strategiescomprisedofoneoptionforeachimplementation 4 issueaddressedintheproposedrule.Thefollowing 0 principlesguidedusinthedevelopmentoftheunderlying   optionsandtheframeworkstoimplementthe8hourozone 8!" NAAQSintheproposedrule:toprotectpublichealth, "4$ provideincentivesforexpeditiousattainmentofthe8hour $& ozoneNAAQSandavoidincentivesfordelay;toprovide <&!( reasonablebutexpeditiousattainmentdeadlines;to '8#* establishabasic,straightforwardstructurethatcouldbe )$, communicatedeasily;toprovideflexibilitytoStatesand @+&. EPAonimplementationapproachesandcontrolmeasureswhile  ensuringthattheimplementationstrategyissupportedby \ theCAA;toemphasizenationalandregionalmeasurestohelp X areascomeintoattainmentand,wherepossible,reducethe   needforthoselocalcontrolsthataremoreexpensivethan `  nationalandregionalmeasures;andtoprovideasmooth  \  transitionfromimplementationofthe1hourozoneNAAQSto   implementationofthe8hourozoneNAAQS.Anadditional d  goalwastoclarifytheroleofTribesinimplementingthe `  8hourozoneNAAQS.XcXX XcSection301(d)oftheCAArecognizes   thattheAmericanIndianTribalgovernmentsaregenerally h theappropriateauthoritytoimplementtheCAAinIndian d country.AsdiscussedintheTribalAuthorityRule(TAR)  (63FR7262,February12,1998,and59FR4396043961, l August25,1994),itisappropriatetotreatTribesinthe h samemannerasStates.Therefore,whenwediscusstherole  oftheStateinimplementingthisrulewearealsoreferring p  totheTribes.# XcXXXc[#nXXX Xcn>+XnXԀ# ӭn>+^## XcX ӭ^#Pleaserefertotheproposedrule(68FR !l" 32802,June2,2003)foradetaileddiscussionand "$ backgroundinformationonthe8hourozoneproblemandEPAs t$& strategyforaddressingit,the8hourozoneNAAQSand  &p!( associatedlitigation,andthestakeholderprocessfor '#* gatheringinputintothiseffort,amongothertopics. x)$,  ` OnAugust6,2002(68FR46536),wepublishedanotice $+t&. ofavailabilityofthedraftregulatorytextfor_the  proposedruletoimplementthe8hourozone_NAAQS_.This \ noticestarteda30daypubliccommentperiodonthedraft X regulatorytext.Inaddition,onOctober21,2003(68FR   60054),wereopenedthepubliccommentperiodfor15daysto `  solicitadditionalcommentonalternativeapproachesfor  \  classifyingozone_nonattainment_Ԁareas,basedoncomments   receivedduringthecommentperiod. d   II.WhatisEPAsScheduleforTakingFinalActiononthe `  Proposal?  (  ` InourJune2,2003proposal,westatedthatweplanned  toissuethefinalimplementationruleinDecemberof2003. L WhilethereisnotaCAAdeadlineforpromulgatinga H strategytoimplementthe8hourozone_NAAQS_,theCAAdoes  establishadeadlineforEPAtopromulgatedesignationsof P _nonattainment_Ԁareasundersection107oftheCAA. C  1      ׀Wehave L  enteredintoaconsentdecreethatrequiresustopromulgate   designationsbyApril15,2004. C  2      ׀Ourgoalwastoissuea   finalimplementationrulebytheendof2003becausethe \ StatesandTribesindicatedastronginterestinhavingan X opportunitytounderstandtheimpactsofbeingdesignated   _nonattainment_Ԁpriortopromulgationofdesignationsforthe `  8hour_NAAQS_.Basedonthelargenumberofpubliccomments  \  receivedonourproposalandourneedtoconsiderand   respondtothosecommentsbeforetakingfinalaction,we d  wereunabletoissueafinalrulepriortoApril15,2004 `  thataddressesallissuesraisedintheproposal.This   finalruleaddressesseveralkeycomponentsoftheproposed h rule:howtheclassificationprovisionsoftheCAAwill d applyforpurposesofthe8hourozone_NAAQS_Ԁandthe  transitionfromthe1hour_NAAQS_Ԁtothe8hour_NAAQS_, l includingwhenthe1hour_NAAQS_Ԁwillberevoked,howanti h backslidingprincipleswillensurecontinuedprogresstoward  attainmentofthe8hourozone_NAAQS_,attainmentdates,and p  thetimingofemissionsreductionsneededforattainment. !l"  ` Withinthenextseveralmonths,weplantoissuea "$ secondfinalrule,Phase2,whichwilladdressmanyofthe t$& planningandcontrolobligationsundersections172and182  &p!( oftheCAAthatwillapplyforpurposesofimplementingthe '#* 8hourozone_NAAQS_.Theseinclude,amongotherthings,_RFP_,  _RACT_,attainmentdemonstrationsandmaintenanceplans,and \ newsourcereview(_NSR_).NeitherPhase1norPhase2will X _addresstheappropriatetestsunderthe8hourozoneNAAQS   fordemonstratingconformityofFederalactionstoState `  implementationplans(SIPs).Aproposedrulewaspublished  \  onNovember5,2003(68FR62689)addressingtransportation   conformityrequirementsapplicablein8hourozone d  nonattainmentareas.Inaddition,EPAisrevisingits `  generalconformityregulationsandplanstoissueaproposed   ruleinthespringof2004. h  III.WhatisIncludedinthisRule?  d  ` Todaysaction,Phase1oftheimplementationrule, , focusesontwokeyimplementationissues:1)classifying  areasforthe8hourNAAQSand2)transitioningfromthe1 4 hourtothe8hourNAAQS,whichincludesrevocationofthe 0 1hourNAAQSandtheantibackslidingprinciplesthatshould   applyuponrevocation.5 C  3      ׀Inaddition,itaddressesseveral 8!" additional,relatedissues.Webelievethatclassifications "4$ andantibackslidingarekeyelementsoftheimplementation $& programthatareofprimaryinteresttotheStatesand <&!( Tribespriortothefinaldesignations.Inaddition, '8#* becausesection182(a)oftheCAAprovidesthat  classificationswilloccur byoperationoflawatthetime \ ofdesignation,EPAbelievesitiscriticalthatthepublic X understandsatthetimeofdesignationshowthe   classificationprovisionswillapply. `  2XcXX Xc IV.InShort,WhatDoesthisFinalRuleContain?   \   ` Thissummaryisintendedtogiveonlyaconvenient $  overviewofourfinalrule.Itshouldnotbereliedonfor   thedetailsoftheactualrule.Thefinalrule(regulatory ,|  text)andthediscussionofitinthenextsectionbelow ( shouldbeconsulteddirectly.  # XcXX2Xcw# ` Boththepreambleandtherulemayusethefollowing 0 termstodiscussfourcategoriesofareasforpurposesof , theantibackslidingprovisions:(1)8hourNAAQS  Nonattainment/1hourNAAQSNonattainment;(2)8hourNAAQS 4 Nonattainment/1hourNAAQSMaintenance;(3)8hourNAAQS 0 Attainment/1hourNAAQSNonattainment;(4)8hourNAAQS   Attainment/1hourNAAQSMaintenance.Thesecategoriesare, 8!" respectively:(1)Areasthatremaindesignated "4$ nonattainmentforthe1hourNAAQSatthetimeof $& designationasnonattainmentforthe8hourNAAQS;(2)Areas <&!( thataremaintenanceareasforthe1hourNAAQSatthetime '8#* ofdesignationasnonattainmentforthe8hourNAAQS;(3) )$, Areasthatremaindesignatednonattainmentforthe1hour @+&. NAAQSatthetimeofdesignationasattainmentforthe8  hourNAAQS;and(4)Areasthataremaintenanceareasforthe \ 1hourNAAQSatthetimeofdesignationasattainmentfor X the8hourNAAQS.   2XcXX XcA.g HowwillEPAreconciletheclassificationprovisionsof `  subparts1and2?HowwillEPAclassifynonattainmentareas  \  forthe8hourstandard?      ` ThefinalruleincorporatesOption2oftheproposal. d  Eachareawithacurrent1hourdesignvalueatorabove `  0.121ppm(thelowest1hourdesignvalueinTable1of   subpart2)willbeclassifiedundersubpart2basedonits h 8hourdesignvalue.Allotherareaswillbecoveredunder d subpart1usingtheir8hourdesignvalues.   ` Inbrief,thisapproachworksasfollows: l ec  ec"0 `   First,wewilldeterminewhich8hourareaswillbe h coveredundersubpart2andwhichundersubpart1.Any  areawitha1hourozonedesignvalue(atthetimeof p  designation)thatmeetsorexceedsthestatutorylevel !l" of0.121ppmthatCongressspecifiedinTable1of "$ section181willbeclassifiedundersubpart2andwill t$& besubjecttothecontrolobligationsassociatedwith  &p!( itsclassification.N C  4      ׀Anyareawitha1hourdesign '#* value(atthetimeofdesignation)thatisbelowthe  levelof0.121ppmwillbecoveredundersubpart1and \ subjecttothecontrolobligationsinsection172.ec!݌X` (#` (# Ќ  ec  ec"0 `   Second,subpart2areaswillbeclassifiedasmarginal,   moderate,serious,severeorextremebasedonthe `  areas8hourdesignvalue(atthetimeof  \  designation).SinceTable1isbasedon1hourdesign   values,andapplicationoftheTableaswrittenwould d  produceabsurdresults,wearepromulgatinga `  regulationtranslatingthethresholdsinTable1of   section181from1hourvaluesto8hourvalues.ec݌h` (#` (# Ќ  Underthefinalclassificationapproach,howwillEPA d classifysubpart1areas?   (գ88 ` Weareadoptingthesecondoptionbutmodifiedasa l resultofcomments.Wearecreatinganoverwhelming h transportclassificationthatwillbeavailabletosubpart1  areasthatdemonstratetheyareaffectedbyoverwhelming p  transportofozoneanditsprecursorsanddemonstratethey !l" meetthedefinitionofaruraltransportareainsection "$ 182(h).However,areaswouldnothavetodemonstratethat t$& transportwasduesolelytosourcesfromoutsidetheState  &p!( (interstatetransport)aswasimpliedbytheJune2,2003 '#* proposal.# XcXX2Xc~#2XcXX XcAllotherareasthatdonotqualifyforthe x)$, overwhelmingtransportclassificationwouldnotbe $+t&. classified.# XcXX2Xc#2XcXX Xc  ProposedIncentiveFeature \  ` Wearenotincludingtheproposedincentivefeaturein X thefinalrule.   B. ` HowwillEPAtreatattainmentdatesforthe8Hour `  ozonestandard?  \   ` Weareadoptingthetimeperiodsforattainmentthatwe   proposedforareasunderbothsubpart1andsubpart2ofthe d  CAA.Forareassubjecttosubpart2oftheCAA,themaximum `  periodforattainmentwillrunfromtheeffectivedateof   designationsandclassificationsforthe8hourstandardand h willbethesameperiodsasprovidedinTable1ofsection d 181(a):  ec  ecא"0 `   Marginal!3yearsecא݌l` (#` (# Ќ  ec  ecx"0 `   Moderate!6yearsecx݌h` (#` (# Ќ  ec  ec"0 `   Serious!9yearsec4݌` (#` (# Ќ  ec  ec"0 `   Severe!15or17yearsecԒ݌p ` (#` (# Ќ  ec  ec_"0 `   Extreme20yearsec_z݌!l"` (#` (# Ќ   ` Consistentwithsection172(a)(2)(A),forareassubject "$ tosubpart1oftheCAA,theperiodforattainmentwillbe t$& nolaterthan5yearsaftertheeffectivedateofthe  &p!( designation.However,EPAmaygrantanareaanattainment '#* datenolaterthan10yearsafterdesignation,ifwarranted x)$, basedonthefactorsprovidedinsection172(a)(2)(A). $+t&. HowwillEPAaddresstheprovisionregarding1year  extensions? \  (88 ` Weareadoptingtheinterpretationthatweproposedon X June2,2003.Underbothsections172(a)(2)(C)and   181(a)(5),anareawillbeeligibleforthefirstofthe1 `  yearextensionsunderthe8hourstandardif,forthe  \  attainmentyear,theareas4thhighestdaily8houraverage   is0.084ppmorless.Theareawillbeeligibleforthe d  secondextensioniftheareas4thhighestdaily8hour `  value,averagedoverboththeoriginalattainmentyearand   thefirstextensionyear,is0.084ppmorless. h C.HowwillEPAimplementthetransitionfromthe1hourto d the8hourstandardinawaytoensurecontinuedmomef  nf  g tumin  Stateseffortstowardcleanerair? l  ` TherearetwokeyissuesthatEPAconsideredtogether h regardingthetransitionfromthe1hourstandardtothe8  hourstandard:(1)whenwillthe1hourstandardnolonger p  apply(i.e.,be revoked);and(2)whatprotectionsarein !l" placetoensurethat,oncethe1hourstandardisrevoked, "$ airqualitywillnotdegradeandthatprogresstoward t$& attainmentwillcontinueasareastransitionfrom  &p!( implementingthe1hourstandardtoimplementingthe8hour '#* standard.Asintheproposedrule,thesecondkeyissuehas x)$, threecomponents:(1)whatrequirementsthatappliedbased $+t&. onanareasclassificationforthe1hourstandardmust  continuetoapplytothatarea;(2)forhowlong;and(3)in \ whatarea.Below,wesetforthourfinaltransition X approachinfourparts:(1)whenwillthe1hourstandardno   longerapply(i.e.,whenwillitberevoked);(2)what1 `  hourobligationsshouldcontinuetoapplyoncethe1hour  \  standardisrevoked;(3)howlongshouldthoserequirements   continuetoapply;and(4)whatisthegeographicarea d  subjecttotherequirement. `  1.f  g f  g f  g f  g WhenwillEPArevokef  g Ԁthe1hourstandard?    ` WeareadoptingOption1.Wewillrevokethe1-hour h standardinfull,includingtheassociateddesignationsand d classifications,1yearfollowingtheeffectivedateofthe  designationsforthe8-hourNAAQS. l 2.Whatrequirementsthatappliedinanareaforthe1 h hourNAAQScontinuetoapplyafterrevocationofthe1hour  NAAQSforthatarea? p   ` Theapproachweareadoptinginthefinalruleis !l" summarizedbelowundertheindividualsectionsdiscussing "$ eachcategoryofareaandtypeofcontrolobligation. t$& a.Section51.905(a)(1):8HourNAAQSNonattainment/1Hour  &p!( NAAQSNonattainment '#*  ` (i)Mandatorycontrolmeasures.Weareadoptingthe x)$, approachweproposed.Allareasdesignatednonattainment $+t&. forthe8-hourozoneNAAQSanddesignatednonattainmentfor  the1hourozoneNAAQSatthetimeofdesignationforthe8 \ hourNAAQSremainsubjecttocontrolmeasuresthatapplied X byvirtueofthearea'sclassificationforthe1-hour   standard. `   ` (ii)Discretionarycontrolmeasures.Weareadopting  \  theapproachwesetforthinourproposedrule.AStatemay   reviseorremovediscretionarycontrolmeasures(including d  enforceablecommitments)containedinitsSIPforthe1hour `  standardsolongastheStatedemonstratesconsistentwith   section110(l)thatsuchremovalormodificationwillnot h interferewithattainmentoforprogresstowardthe8-hour d ozoneNAAQS(oranyotherapplicablerequirementofthe  CAA). l  ` (iii)Measurestoaddressgrowth. Wearenotadopting h theapproachsetforthinourproposedrule.Forareas  designatednonattainmentforthe1hourNAAQSatthetimeof p  designationforthe8hourNAAQSandthataredesignated !l" nonattainmentforthe8-hourNAAQS,themajorsource "$ applicabilitycut-offsandoffsetratiosfortheareas1 t$& hourclassificationwouldnotcontinuetoapplyafter  &p!( revocationofthe1hourNAAQS.# XcXX2Xcm#2XcXX Xc  '#* g 0 ` (iv)f  g f  g PlanningSIPsf  g f  g .f  g x)$,` (#` (# f  g  ` (A)f  g f  g Outstandingrateofprogress(ROP)Obligation. $+t&. Weareadoptingtheapproachsetforthinourproposedrule  forthiscategoryofareas.Statesremainobligatedtomeet \ theCAA-mandatedROPemissionreductiontargetsthatapplied X forthe1-hourstandard,butdiscretionarymeasuresadopted   tomeetthosetargetsmaybemodified,iftheStatemakes `  thenecessaryshowingundersection110(l).  \   ` (B)Unmetattainmentdemonstrationobligations.In   thefinalrule,weareallowingtheStatestochooseamong d  threeoptionsthataretailoredaftertheapproaches `  addressedintheproposedrule.Thus,ratherthan   establishingonemandatoryapproach,weareadoptingarule h thatwillallowStatestochooseanyoneofthefollowing d threeoptions:   A8L9;<=>?@(x8"8"  8^23  0 `   Option1.Submita1hourattainmentdemonstration.8^݌l` (#` (# Ќ  "8"  8H23  0 `   Option2.Submit,nolaterthan1yearafterthe h effectivedateofthe8hourdesignations,anearly  fivepercentincrementofprogressplantowardthe8 p  hourstandard.8Hu݌!l"` (#` (# Ќ  "8"  823  0 `   Option3.Submitanearly8hourozoneattainment "$ demonstrationSIPthatensuresthatthefirstsegment t$& ofRFPisachievedearly.8݌ &p!(` (#` (# Ќ   (8xA8L9;<=>?@ݰb.Section51.905(a)(2):8HourNAAQSNonattainment/1Hour '#* NAAQSMaintenance x)$,  ` (i)Mandatorycontrolmeasures.Weareadoptingthe $+t&. approachwetookintheproposalandthedraftregulatory  text.Thiscategoryofareasmustcontinuetoimplement \ mandatorycontrolrequirements(i.e., applicable X requirements)thathavebeenapprovedintotheSIP.   However,sincemaintenanceareasdonothaveanyoutstanding `  obligationtoadoptmandatorycontrolobligationsforthe1  \  hourstandard,theprovisiononlyaddressesimplementation,   notadoption.Inaddition,thissectionrecognizesthat d  maintenanceareashadtheflexibilitytomovemandatory `  controlstothecontingencymeasuresportionoftheir   maintenanceplan. h  ` (ii)Discretionarycontrolmeasures.Aswith d discretionarycontrolmeasuresfor8hourNAAQS  nonattainment/1hourNAAQSnonattainmentareas,1hourNAAQS l nonattainment/1hourNAAQSmaintenanceareaswillretainthe h discretiontomodifyanydiscretionarycontrolmeasuresupon  ademonstrationundersection110(l).Wearenot p  promulgatingregulatorytextbecausesections110(l)and193 !l" oftheCAAgovernsuchSIPrevisions. "$  ` (iii)Measurestoaddressgrowth.Weareadoptingthe t$& approachweproposed,butourrationalereliesonthefinal  &p!( rulesprovisionthatNSRunderthe1hourstandardwillno '#* longerbearequiredimplementationplanelementasof x)$, revocationofthe1hourstandard.Ifanareahasbeen $+t&. redesignatedtoattainmentforthe1hourstandardasofthe  effectivedateofthe8hournonattainmentdesignationand \ isnolongerrequiredtoimplementanonattainmentNSR X program,theareawillnotberequiredtorevertbacktothe   programithadforpurposesofthe1hourozonestandard. `   ` Asnotedelsewhere,NSRoffsetratiosandmajor  \  stationarysourceapplicabilityprovisionsunderthe1hour   standardarenotbeingdefinedas applicablerequirements d  afterthe1hourstandardisrevoked. `   ` (iv)PlanningSIPs.Weareadoptingtheapproach   takeninthedraftregulatorytext.Inredesignatingan h areatoattainment,EPAmustconcludethattheareahasmet d allrequirementsapplicableundersection110andpartD.  Thus,maintenanceareasdonothavecontinuingprogressand l attainmentdemonstrationrequirements. h c.Section51.905(a)(3):8HourNAAQSAttainment/1Hour  NAAQSNonattainment p   ` (i)Mandatorycontrolobligations.Weareadoptingan !l" approachconsistentwithourproposedrule.Wehave "$ determinedthatmandatorycontrolobligationswillnolonger t$& applyonceanareaattainsthe8hourstandard.Thus,  &p!( becausetheseareasareattainingthe8hourstandard,the '#* Statemayrequestthatobligationsunderapplicable x)$, requirementsbeshiftedtocontingencymeasuresoncethe1 $+t&. hourstandardisrevoked,consistentwithsections110(l)  and193oftheCAA.However,theStatecannotremovethe \ obligationsfromtheSIP. X  ` (ii)Discretionarycontrolobligations.8hourNAAQS   attainment/1hourNAAQSnonattainment# XcXX2Xc#2XcXX XcԀareaswillretainthe `  discretiontomodifyanydiscretionarycontrolsupona  \  demonstrationundersection110(l).However,suchcontrols   mustremainintheSIPascontingencymeasures. d   ` (iii)Measurestoaddressgrowth.Weareadoptingthe `  approachwesetforthinourproposedruleforthiscategory   ofareas.Afterthe1hourstandardisrevoked,theCAA h requiressuchareastocomplywithpreventionofsignificant d deterioration(PSD),notNSR.   ` (iv)PlanningSIPs.Weareadoptingourproposalwith l somemodification.Anareaofthiscategorywillnotbe h requiredtodevelopandsubmitoutstandingattainment  demonstrationandROPplansf  g f  g f  g forthe1hourstandardforso p  longastheareacontinuestomaintainthe8hourNAAQS. !l" However,iftheareaviolatesthe8hourNAAQSpriorto "$ havinganapproved8hourmaintenanceplanundersection t$& 110(a)(1),theareawillberequiredtosubmitaSIP  &p!( revisiontoaddressoutstandingROPandattainment '#* demonstrationplans. x)$,  ` (v)Maintenanceplansforthe8hourNAAQS.Weare $+t&. adoptingtheapproachweproposed.Areasthatareeither8  hourNAAQSattainment/1hourNAAQSnonattainmentor8hour \ NAAQSattainment/1hourNAAQSmaintenancemustadoptf  g f  g Ԁand X submitf  g af  g maintenanceplanf  g Ԁconsistentwithsection110(a)(f  1)g    f  g within3yearsofdesignationasattainmentforthe8hour `  NAAQS.f  g ԀThef  g Ԁmaintenanceplanf  g Ԁshouldprovideforg continued  \  f  g maintenanceofthe8hourstandardfor10yearsfollowing   f  g f  g f  g designationforthe8hourNAAQSf  g f  g Ԁandshouldinclude d  contingencymeasures. `  d.Section51.905(a)(4):8HourNAAQSAttainment/1Hour   NAAQSMaintenance h  ` Inthefinalrule,wecreatedasection51.905(a)(4)to d applytothiscategoryofareas.Itcoversobligationsin  anapprovedSIPandmaintenanceplanssimilarinmannerto l areasthatareattainmentforthe8hourstandardandwere h attainmentforthe1hourstandardandhadamaintenance  plan. p  3.Forhowlongdotheseobligationscontinuetoapply? !l"   ` WeareadoptingOption2!controlobligationsanarea "$ isrequiredtoretainintheapprovedSIPforanareas1 t$& hourclassificationmustcontinuetobeimplementedunder  &p!( theSIPuntiltheareaattainsandisredesignatedto '#* attainmentforthe8hourNAAQS.Atthattime,theState x)$, mayrelegatesuchcontrolstothecontingencymeasure $+t&. portionoftheSIPiftheStatedemonstratesinaccordance  withsection110(l)thatdoingsowillnotinterferewith \ maintenanceofthe8hourNAAQSoranyotherapplicable X requirementoftheCAA.Ifatthetimetheareais   redesignatedtoattainmentforthe8hourstandardtheState `  hasanoutstandingobligationtoadoptacontrolrequirement  \  underthe1hourstandard,itremainsobligatedtodoso,   butmayadoptitasacontingencymeasure. d  4.Whichportionsofanareadesignatedforthe8hour `  NAAQSremainsubjecttothe1hourNAAQSobligations?    ` Thefinalruleincorporatesmostaspectsofthe h approachasthatcontainedintheproposalandinthedraft d regulatorytext.Thefinalruleprovidesthatonlythe  portionofthedesignatedareaforthe8-hourNAAQSthatwas l designatednonattainmentforthe1-hourNAAQSisrequiredto h complywiththeplanningobligations,exceptinone  circumstance:iftheStateelectstoprovideanearly p  incrementofprogressoranearly8-hourattainment !l" demonstrationinlieuofanoutstanding1-hourattainment "$ demonstration(foran8hourNAAQSnonattainment/1hour t$& NAAQSnonattainmentareaunder51.905(a)(1)(ii)(B)and(C)),  &p!( theincrementofprogressorearly8-hourattainmentplan '#* mustapplyforpurposesoftheentire8-hournonattainment x)$, area. $+t&.  ` Thefinalruledoesnotfollowtheapproachinthe  proposalforthemaintenanceplanrequirementfor8hour \ attainmentareas.Themaintenanceplansrequiredforthese X areasmustdemonstratemaintenanceonlyforthearea   designatednonattainmentforthe1hourNAAQSatthetimeof `  designationofthe8hourstandard.  \  5.Whatobligationsthatappliedforthe1hourNAAQSwill   nolongerapplyafterrevocationofthe1hourNAAQSforan d  area? `   ` Wearerevisingtheapproachwesetforthinour   proposedrule.Inadditiontotheobligationsnotedinour h proposalthatwouldnolongerapplyafterthe1hourNAAQS d isrevoked,wearealsoprovidingclarificationregarding  thepenaltyobligationsundersections181(b)(4)and185Aof l theCAAthatapplyinsevereandextremeareasthatdonot h attainthe1hourstandardbytheapplicableattainment  date.ThefinalrulealsowouldnotretainNSRunderthe1 p  hourNAAQS.Thefinalruleprovidesthatasofthe !l" effectivedateofrevocationofthe1hourstandard: "$ ec  ec"0 `   f  Wewillnolongermakefindingsoffailuretoattain t$& the1hourstandardand,therefore,f  g Ԁ(a)wewillnot  &p!( reclassifyareastoahigherclassificationforthe1 '#* hourstandardbasedonsuchafinding,and(b)areas x)$, thatwereclassifiedassevereorextremeforthe1 $+t&. hourNAAQSarenotobligatedtoimposefeesasprovided  undersections181(b)(4)and185AoftheCAAunderthe \ 1hourstandard.ec݌X` (#` (# Ќ  ec  ecW"0 `   Areasf  g willnotbeobligatedtocontinuetodemonstrate   conformityforthe1hourNAAQSasoftheeffective `  dateoftherevocationofthe1hourNAAQS.# XcXX2Xcp#ecWr݌ \ ` (#` (# Ќ  ec  ec"0 `   Anareawithanapproved1-hourmaintenanceplanunder   section175AoftheCAAmaymodifythemaintenanceplan d  toremoveobligationsrelatedtodevelopingasecond `  10yearmaintenanceplanforthe1-hourNAAQSandthe   obligationtoimplementcontingencymeasuresupona h violationofthe1-hourNAAQS.ec݌d` (#` (# Ќ  ec  ec"0 `   NSRunderthe1hourNAAQSwillnolongerbearequired  implementationplanelementinareasthatare8Hour l NAAQSnonattainment/1HourNAAQSnonattainment.2XcXX XcԀ h Instead,NSRunderthe8hourNAAQSwillapply.ec݌` (#` (# Ќ  6.WhatisthecontinuedapplicabilityoftheNOxSIPCall p  afterrevocationofthe1hourNAAQS? !l"  ` Weareadoptingtheapproachwesetforthinour "$ proposedruleanddraftregulatorytext.Statesmust t$& continuetoadheretotheemissionbudgetsestablishedby  &p!( theNOxtransportrulesafterthe1hourstandardis '#* revoked.Statesretaintheauthoritytorevisecontrol x)$, obligationstheyhaveestablishedforspecificsourcesor $+t&. sourcecategoriesundertheNOxSIPCallrulesolongasthe  Statedemonstratesconsistentwithsection110(l)thatsuch \ modificationwillnotinterferewithattainmentofor X progresstowardmeetingthe8hourNAAQSoranyother   applicablerequirementoftheCAA. `  D.Whatistherequiredtimeframeforobtainingemissions  \  reductionstoensureattainmentbytheattainmentdate?    ` Weareadoptingtheapproachwesetforthinour d  proposedrule,namelythatemissionsreductionsneededfor `  attainmentmustbeimplementedbythebeginningoftheozone   seasonimmediatelyprecedingtheareasattainmentdate. h # XcXX2Xc# V.EPAsFinalRule  d A.g HowwillEPAreconciletheclassificationprovisionsof , subparts1and2?HowwillEPAclassifynonattainmentareas  forthe8hourNAAQS?(SectionVI.A.ofproposal;see68FR 4 32811;section51.902ofdraftandfinalrules) 0 1.Background   a.f  g f  g StatutoryframeworkandSupremeCourtdecision.TheCAA 8!" containstwosetsofrequirements!subpart1andsubpart2 "4$ !thatestablishrequirementsforStateplansimplementing $& theozoneNAAQSinnonattainmentareas.(Botharefoundinf  g  <&!( titleI,partD.)f  g ԀSubpart1f  g Ԁcontainsgeneral,less '8#* prescriptive,requirementsforSIPsforf  g nonattainmentareas )$, f  g f  g foranypollutant!includingozone!governedbyaNAAQS. @+&. Subpartf  g Ԁ2providesmorespecificrequirementsforozonef  g   nonattainmentSIPsf  g .a C  5       \ f  g  ` Whenwepromulgatedthe8hourozoneNAAQSon&  ԀJuly18,' ` X 1997,weindicatedthatweanticipatedthatStateswould   implementthe8hourNAAQSunderthelessprescriptive `  subpart1requirements.Morespecifically,weconcluded  \  thattheCAArequiredareasdesignatednonattainmentforthe   1hourozoneNAAQStoremainsubjecttothesubpart2 d  requirementsforpurposesofthe1hourNAAQSuntilsuch `  timeastheymetthatNAAQS(62FR38872).Wealsostated   thatthoseareasandallotherareaswouldbesubjectonly h tosubpart1forpurposesofplanningforthe8hourozone d NAAQS.Wedeterminednottoimmediatelyrevokethe1hour  NAAQSforallareasbuttopromulgatearule(40CFR l 50.9(b))providingthatthe1hourNAAQSandtheassociated h designationwouldnolongerapplytoanareaonceEPA  determinedtheareahadattainedthe1hourNAAQS.Thus, p  areasthathadnotyetattainedthe1hourNAAQSretained !l" theirdesignationforthatNAAQSandremainedsubjecttothe "$ controlobligationsassociatedwiththeirclassificationfor t$& the1hourNAAQSuntiltheymetit.  &p!(  ` InFebruary2001,theSupremeCourtruledthatthe  statutewasambiguousastotherelationshipofsubparts1 \ and2forpurposesofimplementingthe8hourNAAQS. X Whitmanv.AmericanTruckingAssociations,531U.S.457,   48186(2001).TheCourtconcluded,however,thatthe `  implementationapproachsetforthinthefinalNAAQSrule,  \  whichprovidednoroleforsubpart2inimplementingthe8   hourNAAQS,wasunreasonable.Id.Specifically,with d  respecttoclassifyingareas,theSupremeCourtstated: `   [D]oessubpart2provideforclassifyingnonattainment   ozoneareasundertherevisedstandard?f  g Ԁf  g Itunquestionably h does.Whitman,531U.S.at482. d  ` Despiterecognizingthattheclassificationprovisions  ofsubpart2(section181(a))applyforpurposesofthe8 l hourNAAQS,theSupremeCourtalsorecognizedthatthe h subpart2classificationschemedoesnotentirelyfitwith  therevised8hourNAAQSandleftittoEPAtodevelopa p  reasonableresolutionoftherolesofsubparts1and2in !l" classifyingareasforandimplementingarevisedozone "$ NAAQS.Id.at482486. t$&  ` Inparticular,theCourtnotedg f  g Ԁthreeportionsof  &p!( section181!theclassificationprovisioninsubpart2f  g f  g ! '#* thatitindicatedwere illfittedtoimplementationofthe x)$, revisedstandard.Id.at483. $+t&.  A8L9;<=>?@(x8"8"  823  0 `   f  g First,theCourtrecognizedthat usingtheold1hour  averagesofozonelevels...assubpart2requires... \ wouldproduceatbestaninexactestimateofthenew8 X houraverages...Id.8K݌ ` (#` (# Ќ  "8"  823  0 `   f  g f  g f  g Secondf  g ,theCourtrecognizedthatthedesignvaluesin `  Table1isbasedonthelevelofthe1hourNAAQS(0.12  \  ppm)andnotedthat totheextentthenewozone   standardisstricterthantheoldone,...the d  classificationsystemofSubpart2containsagap, `  becauseitfailstoclassifyareaswhoseozonelevels   aregreaterthanthenewstandard(andthus h nonattaining)butlessthantheapproximationofthe d oldstandardcodifiedbyTable1.Id.f  g f  g 8݌` (#` (# Ќ  "8"  8Ŗ23  0 `   Thirdf  g ,theCourtrecognizedthat Subpart2'smethod l forcalculatingattainmentdates!whichissimplyto h countforwardacertainnumberofyearsfrom  November15,1990...seemstomakenosensefor p  areasthatarefirstclassifiedunderanewstandard !l" afterNovember15,1990.Morespecifically,theCourt "$ recognizedthatattainmentdatesformarginal(1993), t$& moderate(1996),andserious(1999)areashadpassed.  &p!( Id.at483484.8Ŗ݌'#*` (#` (# Ќ  2XcXX Xcb.EPAsproposedruleandnoticereopeningthecomment x)$, period.InlightoftheSupremeCourtsruling,weexamined $+t&. thestatutetodeterminethemannerinwhichthesubpart2  classificationsshouldapplyforpurposesofthe8hour \ ozoneNAAQS.Wepaidparticularattentiontothethree X portionsofsection181thattheSupremeCourtnotedwere   illfittedforimplementationoftherevised8hourNAAQS. `  Weexaminedthoseprovisionsinlightofthelegislative  \  historyandtheoverallstructureoftheCAAtodetermine   whatCongressintendedforpurposesofimplementinga d  revised,morestringentozoneNAAQS. `   ` OnJune2,2003(68FR32802),weissuedaproposed   rulewhichidentifiedtwooptionsforclassifyingareasfor h the8hourozoneNAAQS.UnderOption1(68FR32812),we d proposedtoclassify8hourozonenonattainmentareas  accordingtotheseverityoftheirozonepollutionbasedon l 8hourdesignvalues. C  6      ׀Becausethesubpart2classification h tableisbasedon1hourdesignvalues,weproposedto  translatetheclassificationthresholdsinTable1of p  section181to8hourdesignvalues.Underthisoption,all  8hournonattainmentareaswouldbeclassifiedundersubpart \ 2asmarginal,moderate,serious,severeorextreme. X  ` UnderOption1,thethresholdforthemarginal   classificationwouldbean8hourdesignvalueof0.085ppm . `  Eachofthe8hourclassificationthresholdswouldbethe  \  samepercentageabovethe8hourNAAQSasthecorresponding   statutory1hourthresholdisabovethe1hourNAAQS.For d  example,sincethestatutory1hourozonelevelforthe `  moderateclassificationis15percentabovethe1hour   NAAQS,the8hourozonelevelforthemoderate h classificationwouldbe15percentabovethe8hourNAAQS. d  ` TheEPAdevelopedasecondoptiondesignedtoprovide  Stateswithgreaterflexibilityonthemeasuresincludedin l theirplansformeetingthe8hourNAAQS.UnderOption2 h (68FR32812),whichweindicatedwasourpreferredoption,  weproposedatwostepsystemfordetermining p  classificationsforareas.Weproposedasafirststep,to !l" divideareasintotwogroupsbasedoneachareascurrent1 "$ hourozonedesignvalue.Inaccordancewiththeportionof t$& theSupremeCourtdecisionwhichindicatedthattherewasno  &p!( gapinthestatuteforthoseareaswitha1hourdesign '#* valueabove0.121ppm!thelowestlevelinTable1in x)$, section181(a)!weproposedthatareaswithacurrent $+t&. (i.e.,determinedatthetimeofdesignation)1hourozone  designvaluegreaterthanorequalto0.121ppmwouldbe \ classifiedundersubpart2forthe8hourNAAQS.Forareas X witha1hourdesignvaluelessthan0.121ppm,i.e.,those   areastheCourtstatedfellintothegap,weconcludedthat `  wemustmakeareasonabledeterminationwhethertheyshould  \  becoveredundersubpart1orsubpart2.Weproposedthat   alloftheseareaswouldbecoveredundersubpart1.For d  theareasthatdidnotfallintothegapandwhichmustbe `  classifiedundersubpart2,weproposedtoclassifythem   basedonourtranslationofTable1insection181(a),as h describedunderOption1. d  ` Wereceivedalargenumberofcommentsonthe  classificationoptionsthatweproposed,including l recommendationsforotherapproaches,mostofwhichwere h variationsontheoptionsweproposed.OnOctober21,2003  (68FR60054),f  g wereopenedthecommentperiodonthe p  proposedrulefor15daystoprovidethepublicwithan !l" opportunityforadditionalcommentonalternativeapproaches "$ forclassifyingareasforthe8hourozoneNAAQSthatwere t$& suggestedduringthecommentperiod.Wealsoincludedtwo  &p!( alternativestrategies(AlternativesAandB)for '#* classifyingareasthatEPAdevelopedbycombiningideas x)$, suggestedbydifferentcommentersduringtheinitialcomment $+t&. period. C  7         ` AlternativesAandBweredesignedtoplacemoreareas \ inhigherclassifications,whichwouldprovideareaswith X moretimetoattainbutwouldimposeadditionalmandatory   controlrequirements.Thesealternativesalsoweredesigned `  toavoidorreduceinstancesinwhichasubpart1areacould  \  havehigher8hourozonelevelsthanasubpart2area.    ` AlternativeAwouldclassifyareassolelyonthebasis d  of8hourdesignvalues.Thekeyfeatureofthis `  alternativewasthatEPAwouldcreateaclassificationtable   of8hourvaluesstartingfroman8hourdesignvaluethat, h totheextentpossible,wouldbeapproximatelyequivalentto d the1hourdesignvalueof0.121ppminTable1.Thus,the  lowestlevelintheregulatorytablewasthe8hour l approximationofthe1hourNAAQSassuggestedby h commenters,i.e.,0.091ppm.Areaswithan8hourdesign  valuelessthan0.091ppmwouldbecoveredundersubpart1. p  Areaswithan8hourdesignvalueatorabovethislevel  wouldbeclassifiedundersubpart2.Toplaceareasin \ higherclassifications,wenarrowedtherangeforeach X classificationtouse50percent(insteadof100percent)of   thepercentagesthattheclassificationthresholdswere `  abovethe1hourNAAQSinourproposedJune2003translation  \  ofTable1.  Inotherwords,sincethemoderatethreshold   forthe1hourNAAQSis15percentabovethe1hourNAAQS, d  wewouldadjustthemoderatethresholdforpurposesofthe `  8hourNAAQStobe7.5percentabove0.091ppm(thelowest   levelinTable1forAlternativeA). h  ` AlternativeB,amodifiedversionofOption2,retained d thefirststepofOption2,wherewedividetheareasbased  ontheircurrent1hourdesignvalue.AsinOption2,areas l with1hourdesignvaluesexceedingthestatutory0.121ppm h levelwouldberegulatedundersubpart2.Inaddition,any   gaparea(i.e.,thosewitha1hourdesignvaluelessthan p  0.121ppm)withamoderatelevel(orhigher)designvalue !l" wouldbeclassifiedundersubpart2.Allothergapareas "$ wouldbecoveredbysubpart1.AswithAlternativeA,to t$& placesubpart2areasinhigherclassifications,wenarrowed  &p!( therangeforeachclassificationto50percentoftherange '#* inTable1ofsection181.Inotherwords,themoderate x)$, thresholdwouldbe7.5percentabovethe8hourNAAQS(0.085 $+t&. ppm).  2.Summaryoffinalrule \  ` Afterconsideringallofthecommentsthatwere X submitted,weareadoptingOption2.Eachareawitha   current1hourdesignvalueatorabove0.121ppm(the `  lowest1hourdesignvalueinTable1ofsubpart2)willbe  \  classifiedundersubpart2basedonits8hourdesignvalue.   Allotherareaswillbecoveredundersubpart1usingtheir d  8hourdesignvalues. `   ` Inbrief,thisapproachworksasfollows:   ec  ec/"0 `   First,wewilldeterminewhich8hourareaswillbe h coveredundersubpart2andwhichundersubpart1.Any d areawitha1hourozonedesignvalue(atthetimeof  designation)thatmeetsorexceedsthestatutorylevel l of0.121ppmthatCongressspecifiedinTable1of h section181willbeclassifiedundersubpart2andwill  besubjecttothecontrolobligationsassociatedwith p  itsclassification. C  8      ׀Anyareawitha1hourdesign !l" value(atthetimeofdesignation)thatisbelowthe "$ levelof0.121ppmwillbecoveredundersubpart1and t$& subjecttothecontrolobligationsinsection172.ec/0݌ &p!(` (#` (# Ќ  ec  ec3"0 `   Second,subpart2areaswillbeclassifiedasmarginal, '#* moderate,serious,severeorextremebasedonthe  areas8hourdesignvalue(atthetimeof \ designation).SinceTable1ofsection181isbasedon X 1hourdesignvalues,andapplicationoftheTableas   writtenwouldproduceabsurdresults,weare `  promulgatingaregulationtranslatingthethresholdsin  \  Table1ofsection181from1hourvaluesto8hour   values.(SeeTable1 Classificationfor8HourNAAQS d  forAreasSubjecttoSection51.902(a)insection `  51.903.)ec3 4݌ ` (#` (# Ќ  ec  ec]7"0 `   Third,inaccordancewithsection181(a)(4)and h 181(b)(3),theStatemayrequestalowerorhigher d classification.ec]7x7݌` (#` (# Ќ  ec  ec8"0 `   Finally,asdescribedinmoredetailbelow,section l 172(a)(1)providesEPAwithdiscretionwhetherto h classifyareasundersubpart1andwearecreatingone  classification!forqualifyingareasaffectedby p  overwhelmingtransport.# XcXX2Xc #2XcXX XcԀAllotherareascoveredunder !l" subpart1willnotbeclassified.ec88݌"$` (#` (# Ќ  a.WhydidEPAselectOption2?TheEPAcarefully t$& consideredthemanycommentswereceivedonclassification  &p!( optionsand,infact,soughtadditionalinputon '#* alternativespresentedanddevelopedpursuanttocomments x)$, receivedontheJune2003proposal.Thecommenterswere $+t&. deeplydividedonthemeritsoftheoptions.Evenafterthe  conclusionoftheOctober2003commentperiod,most \ commentersstillfavoredOption2orOption1.Onlyafew X favoredeitherAlternativeAorAlternativeB.Those   commenterswhosuggestedalternativestoOption1orOption `  2duringtheinitial60daycommentperioddidnotsupport  \  AlternativesAandB(whichblendedseveralsuggestionsfrom   theinitialcomments)andtheyremainedconvincedthattheir d  suggestedapproachwasthebestclassificationapproach. `   ` Becausethecommenterswerestronglydividedoverthe   appropriateclassificationapproach,EPAreexaminedthe h variousalternativesinlightoftheirconsistencywiththe d CAA,asinterpretedbytheSupremeCourt,andtheir  consistencywithEPAsstatedgoals.WhileEPAbelieves l thatOptions1and2andAlternativesAandBareall h legallysupportableundertheCAA,weconcludedthatOption  2bestfitswiththepolicygoalsenunciatedbyEPAinthe p  proposalandreaffirmedhere.Thus,EPAhasselected !l" Option2.WeexplainbelowwhyOption2willbest "$ accomplishthepolicygoalsofEPAandwhywebelieveitis t$& consistentwiththeCAA.  &p!(  ` (i)WhywillOption2bestaccomplishthepolicygoals '#* ofEPA?OneofEPAsstatedgoalsatproposalwasto x)$, provideflexibilitytoStatesandTribesonimplementation $+t&. approachesandcontrolmeasureswithinthestructureofthe  CAA.Ascomparedwiththeotheralternativesconsidered, \ Option2placesmoreareasunderthemoreflexible X provisionsoftheCAA(subpart1),whichwillprovidethe   StatesandTribeswithgreaterdiscretionindeterminingthe `  mixofcontrolsneededtoexpeditiouslyattainthe8hour  \  NAAQS.Forexample,Option1wouldplaceallareasunder   subpart2,whichmandatesanumberofspecificcontrol d  measures,thuslimitingtheStatesandTribesabilityto `  considerwhethertherearemoreeffectiveandlesscostly   waystoachievethesamelevelofemissionreductions. C  9      ׀# XcXX2Xc(:#XcXX XcFor h example,anareamightbeabletoachievegreaterair d qualityimprovementatlesscostfromlocalNOxreductions  thanfromlocalvolatileorganiccompounds(VOC)reductions l of15percentmandatedforcertainsubpart2areas.# XcXXXcSG#2XcXX XcԀThis h willenablesomeareastomeetthe8hourNAAQSatlesscost  thanundertheotherclassificationoptionsbecausethe p  StatesandTribeswillhavegreaterflexibilityin !l" determiningwhichcontrolrequirementstoadopttomeetthe "$ NAAQS.BecauseareasarerequiredtoattaintheNAAQSas t$& expeditiouslyaspracticableunderbothsubpart1and  &p!( subpart2,Option2shouldnotresultinlongerattainment '#* periodsthanOption1,withtheexceptionofareas  significantlyaffectedbytransportedpollution(discussed \ below). X  ` Additionally,placingsomeareasinsubpart1provides   StatesandEPAwithgreaterflexibilitytodetermine `  appropriatecontrolsforareasthatwouldhavedifficulty  \  attainingthe8hourNAAQSduetointerstatepollution   transport.Inthe13yearssincetheCAAAmendmentsof1990 d  wereenacted(atwhichtime,Congresscreatedsubpart2),we `  havelearnedmuchaboutthelongrangetransportofozone   andtheimportanceofemployingregionalcontrolsin h additiontolocalcontrols.Subpart2doesnotallowEPA d andtheStatestoconsidertransportedpollutionin  determiningthefeasibilityandbenefitsofmandated l controlsorindeterminingtheappropriateattainmentdate h foranarea. Becauseofourincreasedunderstandingof  transportedpollutionsinceCongressenactedthemore p  restrictiveprovisionsofsubpart2,webelieveitmakes !l" sensetoadoptanapproachthatdoesnotshift gapareas "$ intosubpart2.Inotherwords,whereCongresshasnot t$& explicitlymandatedthatareasaresubjecttosubpart2,we  &p!( dontbelieveitmakessensetoadoptanapproachthatwould '#* shiftsomeorallofthose gapareastosubpart2,which x)$, providessignificantlylessflexibilityforbringingareas $+t&. affectedbytransportedpollutionintoattainment.(We  discussinmoredetailtheflexibilityprovidedbysubpart1 \ andhowitbetterallowsconsiderationofthecurrent X scientificknowledgeregardingozoneformationandtransport   inthesectionbelowdiscussingwhyweplaceallofthe `   gapareasinsubpart1.)  \   ` TheEPArecognizesthattheflexibilityofOption2   comeswithsomeaddedcomplexity.OneofEPAsstatedgoals d  wastoestablishanapproachthatiseasytounderstand. `  WhileOption1(classifyingallareasundersubpart2)is   simpler,webelieveourgoalsregardingflexibilityoutweigh h thesimplicityofOption1.# XcXX2XcH#XcXX Xc d # XcXXXcU# ` AnotherofEPAsstatedaimsatproposalwastoensure  expeditiousbutreasonableattainmentdatesforthe8hour l NAAQS.TheEPAbelievesthatOption2isconsistentwith h thisprinciple.ComparedtoAlternativesAandB,Option2  willplacemoreareasinlowerclassificationswithshorter p  maximumattainmentdates,encouragingexpeditious !l" attainment.Whilesomecommentersbelievedthatmaximum "$ attainmentdatesunderOption2wouldnotallowenoughtime t$& forsomeareastomeettheNAAQS,webelievethatOption2  &p!( providessufficienttimeformostareasandthattothe '#* extentsomeareasmayhavedifficulty,theCAAprovidesan x)$, avenueforrelief,whichisdiscussedbelow. $+t&.  ` Basedoninformationconcerningthehypothetical  nonattainmentareas, C  10      ,  C  11      ׀weareconfidentthatunderOption \ 2mostareascurrentlyexceedingthe8hourNAAQSwillbe X abletomeettheNAAQSwithinthetimelimitsprovidedfor   theirclassification,takingintoconsiderationprojected `  improvementsinairqualityundercurrentprogramsandthe  \  potentialforadoptionoffurthernational,regionaland   localmeasures. d   ` EPAnotesthatthereareuncertaintiesatthistime `  aboutthetimeperiodsneededforattainment,especiallyfor   thelimitednumberofareasneedingsubstantialemissions h reductionstoattain.Forexample,itisdifficultto d determineinadvanceofStatedevelopmentofattainment  planswhensuchanareawillbeabletoattaintheNAAQS.  Theseplansarebasedonhighresolutionlocalairquality \ modeling,refinedemissionsinventoriesanddetailed X analysesoftheimpactsandcostsofpotentiallocalcontrol   measures. `   ` Anotherfactoristhatnewmethodsofachievingcost  \  effectiveemissionsreductionsarecontinuingtobe   developed.Ourrepeatedexperienceoverthepastthree d  decadesisthatmarketforcesstimulatedbytheCAAhave `  repeatedlyledtotechnologicaladvancesandlearning   throughexperience,makingitpossibleovertimetoachieve h greateremissionsreductionsatlowercoststhanoriginally d anticipated. C  12      ׀    `  ` Otheruncertaintiesreflectuseofthemostrecent h threeyearsofairqualitydatafortheactualdesignations  andclaslsifications,anduseofmorerefinedandarea p  specificmodelingmethodologiesforprojectingfutureozone  concentrations. \  ` Regardingtheuseoflaterairqualitydata,wehave X interpretedtheCAAsrequirementsundersection181such   thatwemustclassifynonattainmentareasthatarecovered `  undersubpart2basedonthemostrecentozonedesign  \  values,whicharebasedonthreeyearsofdata.Becauseof   year-to-yearvariationsinmeteorology,this snapshotin d  timemaynotberepresentativeofthenormalmagnitudeof `  problemsthatanumberofareasface.    ` Regardingmodelingmethodologies,national/regional h modelingmayindicatethatanumberofmoderateareasmay d facedifficultyattainingthestandardbythemaximum  attainmentdaterequiredforanareasclassification. l However,whenaStateusingphotochemicalgridmodeling h predictsconcentrationsthatareabovetheNAAQSafter  applicationofSIPcontrols,anoptionalweightofevidence p  determinationwhichincorporates,butisnotlimitedto, !l" otheranalyses,suchasairqualityandemissionstrends, "$ maybeusedtoaddressuncertaintyinherentinthe t$& applicationofphotochemicalgridmodels.(Issuesrelated  &p!( toimplementationofthestandard--includingissuesonthe '#* attainmentdemonstrationandmodeling--willbeaddressed x)$, inthesecondphaseofrulemaking.) $+t&.  ` Weareawarethatsome8hournonattainmentareasin  theEasternU.S.thatareclassifiedmoderateusing2001 \ 2003airqualitydatawillhavedifficultyattainingthe X NAAQSbytheattainmentdateof2010(6yearsafter   designation).WeencourageStatestorequest `  reclassificationupwardwheretheStatefindsthatanarea  \  mayneedmoretimetoattainthantheirclassificationwould   permit.Inaddition,EPAwillconsiderbumpingupareas d  subjecttothefivepercentprovisionofsection181(a)(4) `  oftheCAAonourowninitiativewherethereisevidence   thatanareaisunlikelytoattainwithintheperiodallowed h bytheirclassification.Therulemakingthatsetsforth d designationsandclassificationsforthe8hourstandard  discussescriteriawewoulduseifwetakethisaction. l  ` IfaStatefindsduringtheattainmentplanningprocess h thatfeasiblecontrolsarenotavailableandanareamay  needmoretimetoattainthe8hourNAAQSthantheir p  classificationwouldpermit,thestatuteprovidesaremedy. !l" AStatecanreceivemoretimetoattainbyvoluntarily "$ submittingarequesttoEPAforahigherclassification. t$& Section181(b)(3)oftheCAAdirectsEPAtograntaStates  &p!( requestforahigherclassificationandtopublishnoticeof '#* therequestandEPAsapproval.Althoughtheareawould x)$, havetomeettheadditionalrequirementsforthehigher $+t&. classification,thesamewouldbetrueiftheareahadbeen  initiallyclassifiedhigher,underasystemthatplacedmore \ areasinhigherclassifications.Voluntaryreclassification X maybeanattractiveoptioniftheStateisunableto   developaplanthatdemonstratesanareawillattainwithin `  thetimeperiodforitsassignedclassification.Some  \  commenterswereconcernedthatitmaybedifficultto   developsupportforavoluntaryreclassificationamong d  interestedparties.However,webelievesuchdialoguewill `  leadtheStatetoundertakeathoroughanalysisand   balancingofhowexpeditiouslytheareacanattaintheNAAQS h andthecostofthemeasuresneededforattainmentasthese d issueswillbeforemostinthestakeholdersminds.   ` TheEPAprefersOption2ratherthanthealternatives l thatplacemoreareasintohigherclassificationsbecausein h additiontoprovidingalongermaximumtimeframeinwhichto  attain,thehigherclassificationsimposeadditional p  statutorilymandatedrequirements.Whiletheadditional !l" requirementsmightbeappropriateforareasthattrulyneed "$ thelongerperiodtoattain,itislikelythatanumberof t$& areasthatdonotneedalongerperiodtoattainwouldalso  &p!( beplacedinahigherclassificationunderthese '#* alternatives.Forexample,severalareasthatwouldbe x)$, coveredbysubpart1underOption2,andwhichEPAprojects $+t&. arelikelytoattainthe8hourlevelsNAAQSwithin3years  basedonexistingprograms,wouldbeclassifiedasmoderate \ areasunderAlternativeB. C  13      ׀ Inthoseareas,theadditional X moderateareacontrolrequirementsareunlikelytobeneeded   forexpeditiousattainment. `   ` TheEPAbelievesthatunderanyoftheclassification  \  approachesthatwereconsideredtherewillbeareasthatare    misclassified!i.e.,theclassificationwillnotreflect d  thetimetheareaneedstoattainandthelevelofcontrols `  needed.ThestatutedoesnotallowEPAtoreclassifyan   areatoalowerclassification,exceptasprovidedin h section181(a)(4)regardinganinitial5percentadjustment. d Itdoes,however,asdescribedabove,providecontinuing  authorityforareastobereclassifiedtoahigher l classification.Forthatreason,EPAbelievesthebetter h approachistouseaschemethatmayclassifyareastoolow  andareasthatneedmoretimetoattaincanusethe p  voluntaryreclassificationprovisionoftheCAAtoobtain !l" theappropriateclassification. "$  ` (ii)HowisOption2consistentwiththeCAAas  InterpretedbytheSupremeCourt?Thelegalframeworkfor \ Option2isdescribedindetailintheJune2,2003proposed X rule(68FR32813).Inshort,EPAreliesontheSupreme   Courtsrecognitionthatthereisagapinthestatutewith `  respecttoareas whoseozonelevelsaregreaterthanthe  \  newstandard(andthusnotattaining)butlessthanthe   approximationoftheoldstandardcodifiedbyTable1. d  Thus,forareaswitha1hourdesignvalueabovethelevel `  codifiedinTable1,EPAinterpretstheSupremeCourtas   determiningthattheCAAmandatesthattheybeclassified h undersubpart2.Forallotherareas,theCourtindicates d thereisagapandEPAmustdetermineareasonableapproach  forclassifyingtheseareas.Option2isconsistentwith l theCAAasinterpretedbytheSupremeCourtbecauseit h placesallareaswitha1hourdesignvalueof0.121ppmor  greaterinsubpart2and,forthereasonsprovidedbelow, p  EPAsdecisiontoclassifyall gapareasundersubpart1 !l" isreasonable. "$  ` AswenotedintheJune2,2003proposal(68FR32814), t$& whenfacedwithasimilarissuefollowingenactmentofthe  &p!( CAAAmendmentsof1990,wedeterminedthatareasthat '#* Congressdidnotmandatefallintotheclassificationscheme x)$, ofsubpart2shouldbesubjecttoonlytheplanning $+t&. obligationsofsubpart1. C  14      ׀Wef  g believeitisappropriateto  continuethatinterpretationoftheCAAforf  g 8hourozone \ areasdespitethefactthatasignificantnumberofareas X designatednonattainmentforthe8hourNAAQSwillfallinto   thisgroup.Thisdecisionisreasonablebecausesubpart2 `  wasdevelopedbyCongress13yearsagoandourscientific  \  understandingofthecausesofozonepollutionandthe   transportofozoneanditsprecursorshassignificantly d  advanced.Inaddition,subpart1wasdevelopedatthetime `  thatthe1hourNAAQSwastheNAAQSofconcern.Atthat   time,manyareashadalongtermozoneproblemthattheyhad h beenunabletosolveunderthemoreflexiblepre1990 d provisionsoftheCAA.The8hourNAAQSisdifferentin  manywaysfromthe1hourNAAQS.Moreover,theareasthat l willbesubjecttosubpart1areprimarilyareasthathave h nothadthelongtermpollutionproblemthatCongresswas  concernedaboutwhenitcreatedsubpart2. p   ` g Congressenactedsubpart2withtheunderstandingthat  f  g allareas(exceptmarginalareasf  g f  g ,forwhichfew,ifany, \ controlsforexistingsourceswererequired)wouldhaveto X employadditionallocalcontrolstomeetthe1hourozone   NAAQSinatimelyfashionf  g .Sincethen,manyf  g f  g local,regional `  andnationalcontrolmeasuresf  g Ԁhavebeenimplemented,f  g ourf  g   \  understandingoftheimportanceoff  g Ԁinterstatepollutionf  g    transporthasimproved,andwehavepromulgatedinterstate d  NOxtransportrulestoaddresstransportedpollution(the `  NOxSIPcall,October27,1998,63FR53756).Today,   regionalmodelingf  g ԀbyEPAindicatesthatthemajorityof h potential8f  g f  g Ԅf  g hournonattainmentareasthatfallintothegap d willattainthe8f  g f  g Ԅf  g hourNAAQSby2007basedonf  g reductions  fromf  g thef  NOxg f  g ԀSIPCall,f  g f  g f  g theFederalMotorVehicleEmissions l ControlProgram,f  g ԀandotherexistingFederalandState h controlmeasures,withoutfurtherlocalcontrols.   ` Somegapareaswouldbeclassifiedasmoderatef  g f  g Ԁareasif p  placedundersubpart2.TheEPAregionalmodelingshows !l" thatmanyoftheseareprojectedtoattainby2007through "$ existingregionalornationalmeasures.(Theproposal t$& providesestimatesofthenumbersofareas,see68FR32814,  &p!( col.3). C  15      ׀Iftheseareasweretobeclassifiedas '#* moderate,theywouldberequiredtoimplementstatutorily  specifiedcontrolsformoderateareas.Webelieveitis \ reasonabletoadoptanapproachthatwouldnotmandatenew X localcontrolsinareasprojectedtomeettheNAAQSwithin3   yearsthroughemissionsreductionsrequiredbyexisting `  programs.  \   ` Somecommenterscontendedthatplacingtheseareasin   subpart1createdan equityproblembecauseotherareas d  withasimilar8hourozonedesignvaluewouldbeplaced `  undersubpart2.TheEPAconsideredthisissuewhenit   reopenedthecommentperiodandsetforthalternativesthat h wouldhaveplacedareaswithsimilar8hourdesignvaluesin d thesameclassification.Whileinonelightsucha  situationmaybeperceivedasinequitable,EPAbelievesthat l thisisgenerallynotthecase.Asaninitialmatter,EPA h notesthattheareasthatfallundersubpart2areareas  withhigherozone1hourpeakconcentrations!i.e.,areas p  withlevelsabovethe1hourNAAQS. C  16      ׀Thus,theareas !l" classifiedundersubpart1donothavethesametypeof  ozoneproblemasthoseclassifiedundersubpart2andthe \ samecontrolprogramsmaynotbeneededforbothtypesof X areas.Wenotethattheareasthatwillbeclassifiedunder   subpart2arethetypeofareathatCongressconsideredat `  thetimethatitdevelopedsubpart2anditismorelikely  \  thatsubpart2willprovidebenefitsfortheseareas.We   alsonotethatintheproposedrule,weproposedseveral d  waystomaketheobligationsundersubpart1similarto `  thoseundersubpart2forareaswithasimilarozone   problem.Thus,thereareothermeanstoaddressany h inequities;EPAwillconsiderequityandotherfactorsin d decidingcontrolrequirementsforsubpart1areasinPhase  2.2XcXX Xc l  ` Mostofthegapareaswouldbeclassifiedasmarginal h ifclassifiedundersubpart2by8hourdesignvalue. C  17      ׀    Becausef  g Ԁcontrolrequirementsf  g formarginalareasaresimilar  tothoseforsubpart1areas,andbecausemostofthese \ areasareprojectedtoattainwithin3years,the X distinctioninregulatorycategorymaymakenopractical   differencef  g formanyf  g ofthesef  g areas.f  g f  g ԀHowever,placingthese `  areasundersubpart1providesStatesandEPAwithgreater  \  discretiontohandleimplementationdifficultiesthatmight   ariseinsomeoftheseareas.Forexample,agapareamight d  beunabletoattainwithinthemaximumattainmentdatefor `  marginalareas(3yearsafterdesignation)becauseof   pollutiontransportfromanupwindf  g Ԁnonattainmentf  g f  g areawitha h laterattainmentdeadline.Inthatevent,subpart2would d callfortheareatobereclassifiedasmoderateandforthe  areatoimplementadditionallocalcontrolsspecifiedfor l moderateareas.Forareasundersubpart1,however,f  g we h f  g f  g couldprovideadditionaltimefortheareatoattainwhile  theupwindsourcesimplementedrequiredcontrolsifthis p  weredeterminedtobeamoreeffectiveormoreappropriate !l" solution.Althoughregionalmodelingprojectionsindicate "$ thattheNOxSIPCallwillbringmostgapareasinto t$& attainmentby2007,someStateshavevoicedconcernthat  &p!( interstateorintrastatepollutiontransportmaymaketimely '#* attainmentdifficultforsome8hourareaswithnearterm x)$, attainmentdeadlines(e.g.,2007).Subpart1wouldprovide $+t&. StatesandEPAwithmoreflexibilityontheremedyinany  suchcases,whilestillrequiringthatsubpart1areasadopt \ allreasonablyavailablecontrolmeasurestoattainas X expeditiouslyaspracticable. C  18      ׀Somemayperceivethe   placementofgapareasinsubpart1(basedontheir1hour `  designvalues)asinequitablecomparedtoplacingother  \  areasthathavesimilar8hourdesignvaluesinsubpart2   (basedontheir1hourdesignvalues).Wedonotbelieve, d  however,thatitmakessensetolimitourauthorityby `  placinggapareasinsubpart2eventhoughtheymayhave8   hourdesignvaluessimilartoareasthatwillbeclassified h undersubpart2.# XcXX2Xc؞# d  ` AnadvantageofAlternativesAandBwasthatthey  avoidedorreducedequityconcernsraisedbysomecommenters l withOption2.Regardless,webelievethatequity h considerationsshouldnotoverrideotherconsiderationsin  determininghowtobesthelpareasattainthe8hourNAAQS. p  Congressmandatedthatareaswith1hourozonelevelsabove !l" thelevel0.121ppmbeclassifiedundersubpart2.However,  Congressdidnotspecificallyaddresstheareasthatfall \ intothe gap.WhereCongresshaslefttoEPAsdiscretion X howtoclassifyareas,webelievethatfactorswehave   consideredabovet C  19      ׀outweighanydesirefor equity. `   ` Additionally,wenotethatsince1990wehavelearned  \  thatNOxcontrolismoreimportantformanyareasthanwas   recognizedatthetimeofthe1990CAAAmendments.Some d  mandatorymeasuresinsubpart2,suchasthe15percentVOC `  reductionrequiredforcertainareas,focusonVOC   reductions.Insomeareasitwillbemoreeffectiveand h lesscostlytoreduceozonethroughastrategythatplaces d moreemphasisonNOxthanVOC,anda15percentVOC  reductionmaynotbepartofanoptimalstrategy.Subpart1 l wouldallowsuchareasgreaterflexibilityonchoiceof h controls.  2XcXX Xc ` Insummary,# XcXX2XcR#Option2meetsthepolicygoalsEPA p  specifiedintheproposal!mostimportantly,providing !l" flexibility,andencouragingexpeditiousattainmentofthe "$ NAAQS!andisconsistentwiththeSupremeCourtsruling.  Commentersweredividedonthemeritsofdifferent \ classificationapproachesandnosingleoptionappealedtoa X largemajorityofstakeholders.Onbalance,EPAdetermined   thatOption2waspreferabletotheotheroptions `  identified.Thus,EPAisadoptingOption2.  \  3. ` Commentsandresponses    ` Thispreamblebrieflysummarizesmajorcommentsoneach d  portionofthePhase1ruleandgenerallyprovidesabrief `  responsetothosecomments.Theresponsetocomment(RTC)   documentpresentsamorecompletedescriptionofcomments h receivedandamorecompleteresponsetothosecomments. d COMMENT:Thecommentersweresplitonwhetherthey  preferredOption1,underwhichallareasareclassified l undersubpart2oftheCAA,orOption2,underwhich8-hour h nonattainmentareaswith1-hourozonedesignvaluesof0.121  ppmorgreateratthetimeofdesignationareclassified p  undersubpart2andallother8-hournonattainmentareasare !l" classifiedundersubpart1.ThosewhosupportedOption2, "$ indicateditmadebetterpolicysense,wasmoreflexibleand t$& moreappropriatethanOption1,costless,wasbetter  &p!( integratedwithotherregulations,providedmorereasonable '#* attainmentdates,andwasmoreconsistentwiththeSupreme x)$, Courtdecision.AnumberofcommenterssupportedOption2, $+t&. butrecommendedvariationsofthatapproach.These  commentersraisedone(orboth)oftwoconcernswiththe \ approachrecommendedbyEPA:(1)sincemostoftheareas X fallintothelowerclassificationswithshort-term   attainmentdates,itdoesnotprovidesufficienttimefor `  manyareastoattain;and(2)sincesomeareasclassified  \  undersubpart1willhaveamoresevere8-hourozoneproblem   thansomeareasclassifiedundersubpart2,Option2isor d  maybeperceivedasinequitable.Inaddition,several `  commentersrecommendedoptionsdifferentthaneitherofthe   optionsproposedbyEPA. h  ` ThosewhofavoredOption1arguedthatitwasmore d consistentwiththeSupremeCourtsdecisionandtheCAA,  thatSubpart2wasmorelikelytoproduceprogressand l fasterattainment,wasmoreconsistentwithSubpart2ofthe h CAA,wasmoreequitableandfair,andthatSubpart1had  otherproblemsthatmadeitlessdesirable. p   ` 2XcXX XcSomecommentersclaimedbothOptions1and2were !l" flawed,basedonconcernsabouttransportandconcerns "$ relatedtotheSupremeCourtdecision.# XcXX2Xc#Wereceivedcomments t$& onthetranslationofSection181'sTable1.Thesecomments  &p!( addressedtheconcernssuchas:theproposedtranslation '#* couldresultinattainmentdeadlineswhichareunrealistic x)$, andunachievable;itwouldbemorelogicalandmore $+t&. consistentwiththenatureofthestandardbeingimplemented  Єthe8hourstandardforEPAtof  g f  g translatetheTable1 \ thresholdsintoapproximate8hourequivalents;andthe X startingthresholdshouldbedifferentfromwhatEPA   proposed.Somecommentersofferedotheralternativesfor `  thetranslationand/orthestartingthreshold.  \   ` Therewereseveralspecificcommentsrelatedtothe   draftregulatorytext. d   ` OurrationaleforadoptingOption2asthefinal `  classificationapproachispresentedabove.Belowisa   briefsynopsisoftheresponsetomajorcomments.  h RESPONSETOCOMMENTSSUPPORTINGOPTION2:Wegenerally d agreewiththesecommentsandthefinalruleincorporates  Option2. l RESPONSETOCOMMENTSTHATSUPPORTEDOPTION2,BUT h RECOMMENDINGVARIATIONSTHATWOULDPROVIDEMORETIMEFOR  ATTAINMENT:Basedonourprojectionsoffutureairquality p  basedonregionalmodelingandexperiencewithozonecontrol !l" inthepast,webelievethatStatesmayfindduringthe "$ attainmentplanningprocessthatalimitednumberofareas t$& mayneedmoretimetoattainthe8-hourNAAQSthantheir  &p!( classificationwouldpermit.However,thestatuteprovides '#* aremedyforthissituation.AStatecanreceivemoretime x)$, toattainbyvoluntarilysubmittingarequesttoEPAfora $+t&. higherclassification!includingtheclassificationthey  hadunderthe1-hourNAAQS.TheCAA(Section181(b)(3)) \ directsEPAtograntaStatesrequest,andtopublish X noticeoftherequestandEPAsapproval.Althoughthearea   wouldhavetomeettheadditionalrequirementsforthe `  higherclassification,thesamewouldbetrueifthearea  \  hadbeeninitiallyclassifiedhigher,underaclassification   systemthatplacedmoreareasinhigherclassifications. d  TheEPArecognizesthatvoluntaryreclassificationisa `  legitimateoptionundertheCAA,andmaybeanattractive   optioniftheStateisunabletodevelopaplanthat h demonstratesanareawillattainwithinthetimeperiodfor d itsassignedclassification.AsnotedintheOctober21,  2003noticereopeningthecommentperiod,weconsidered l otherclassificationapproaches,includingthosesuggested h bycommentersandEPAsAlternativesAandB,whichwould  providemoreareaswithlaterattainmentdatesbyplacing p  moreareasinhigherclassifications.However,EPAfound !l" thatalternativesthatprovidedmoretimetotheareaswith "$ theworstozoneproblemsalsoprovidedhigher t$& classifications,accompaniedbyadditionalstatutorily  &p!( mandatedrequirements,forareasthatEPAbelievesmay '#* attainbythe2007ozoneseasonbasedonprojectedemissions x)$, reductionsfromexistingprograms.Undertheseapproaches, $+t&. theseareaswouldbesubjecttocontrolsthatmaynotbe  necessaryforattainment.TheEPAbelievesitismore \ appropriatetousethestatutorymechanismforavoluntary X bumpupforareasclassified toolowthantomandate   controlsforareasbasedonaclassificationthatis too `  high.  \  RESPONSETOCOMMENTSTHATNOTEDTHATOPTION2MAYBE   PERCEIVEDASINEQUITABLE:Anumberofothercommenters d  dismissedthecharacterizationofOption2asbeing `  inequitable.TheEPAsresponsetotheequityissueis   discussedabove. h RESPONSETOCOMMENTSTHATRECOMMENDEDOPTIONSDIFFERENTTHAN d THEOPTIONSPROPOSEDBYEPA:Certaincommenterssuggested  thatareasstillnotmeetingthe1hourNAAQSshould l continuetoimplementthe1hourNAAQSundersubpart2,but h oncetheNAAQSisattained(orallmandatedcontrolswere  implemented)theareawouldimplementthe8hourNAAQSunder p  subpart1.Allareasattainingthe1hourNAAQSwouldbegin !l" implementingthe8hourNAAQSundersubpart1. "$  ` Asexplainedmorefullyintheresponsetocomments t$& (RTC)document,EPAdoesnotbelievethisapproachis  &p!( consistentwiththeCAAortheSupremeCourtsdecisionon '#* implementationofarevisedozoneNAAQS.Theissuebefore x)$, theCourtwaswhethertheclassificationprovisionsof $+t&. subpart2applyforpurposesofimplementingtherevised8  hourozoneNAAQS.TheCourtunequivocallystatedthatthose \ provisionsdoapplyforpurposesofimplementingthe8hour X ozoneNAAQS.531US48284.Webelievethatanyoption   thatdoesnotprovidearoleforthesubpart2 `  classificationstructureinimplementingthe8hourNAAQSis  \  notconsistentwiththeCourtsinterpretationoftheCAA.    ` Commenterssuggestedseveralotheroptions,someof d  whichweredescribedinournoticereopeningthepublic `  commentperiod.Underoneoftheseoptions,wewouldreduce   therangeforthesubpart2classifications,whichwould h haveclassifiedmoresubpart2areasinhigher d classifications,therebyextendingthemaximumperiodfor  attainment.Wehaveaddressedtheproblemsassociatedwith l thatkindofclassificationstructureabove.Underanother h oftheseoptions,theclassificationstructurewouldhave  reliedsolelyon8-hourozonedesignvalues.Thisapproach p  wasavariantofOption2inwhichallareaswith8-hour !l" designvalueoflessthanavaluethatisequivalenttothe "$ 1-hourvalueof0.121ppmwouldbecoveredbysubpart1. t$& ThisvariantofOption2hastheeffectofmovingsource  &p!( areasfromSubpart1toSubpart2andatthesametime '#* placingmoreSubpart2areasinlowerclassification x)$, categories.TheSubpart2areasplacedintheselower $+t&. classificationcategorieswouldbesubjecttofewer  mandatoryrequirements.However,EPAbelievesthatthis \ approachwouldincreasethenumberofareasforwhichthe X initialclassificationwouldnotprovidesufficienttimeto   attain.2XcXX Xc `  # XcXX2Xc#2XcXX Xc ` TheEPAsassessmentoftheseandotheroptionsis  \  includedintheRTCdocument.  # XcXX2XcX#   RESPONSETOCOMMENTSTHATFAVOREDOPTION1ANDARGUEDTHAT d  ITWASMORECONSISTENTWITHTHECOURTDECISIONANDTHECAA: `  WebelieveOption2isareasonablemethodforaddressing   thegapsthattheSupremeCourtrecognizedintheCAA. h Option2providesmoreflexibilitythanOption1toStates d andTribestodesignstrategiestomeetthe8-hourozone  NAAQSinthemosteffectiveandleastcostlywayconsidering l localcircumstances,whilerequiringandproviding h incentivesforexpeditiousattainmentofthehealth-based  NAAQS.SinceOption1wouldrequireall8-hour p  nonattainmentareastobecoveredundersubpart2withits !l" setofprescriptivecontrolmeasures,itwouldgenerally "$ costmorebutwouldnotrequireattainmentanymore t$& expeditiouslythanOption2.Bothsubpart1and2require  &p!( attainmentdates asexpeditiousaspracticableregardless '#* ofthemaximumattainmentdatesspecifiedintheCAA. x)$,  ` WebelievethatOption2isconsistentbothwiththe $+t&. CAAandtheSupremeCourtsdecisioninWhitmanasdescribed  aboveandintheJune2,2003proposedrule(68FR32813). \ Inshort,EPAreliesontheSupremeCourtsrecognitionthat X thereisagapinthestatutewithrespecttoareas whose   ozonelevelsaregreaterthanthenewstandard(andthusnot `  attaining)butlessthantheapproximationoftheold  \  standardcodifiedbyTable1.Thus,forareaswitha   1-hourdesignvalueabovethelevelcodifiedinTable1,EPA d  interpretstheSupremeCourtasdeterminingthattheCAA `  mandatesthattheybeclassifiedundersubpart2.Forall   otherareas,theCourtindicatesthereisagapandEPAmust h determineareasonableapproach.Forthepolicyreasons d specifiedabove,intheRTCandinthepreambletothe  proposedrule(68FR32814-15),EPAbelievesitis l reasonabletoaddressthese gapareasundersubpart1. h RESPONSETOCOMMENTSASSERTINGTHATEPADOESNOTHAVE  AUTHORITYTOMODIFYTABLE1TOREFLECT8HOUROZONEVALUES: p   WedisagreewiththosecommenterswhoclaimEPAdoesnot !l" haveauthoritytomodifyTable1insection181(a)to "$ reflect8hourdesignvalues.WeacknowledgethatEPAis t$& applyingthestatuteotherthaninthewayitiswritten.  &p!( Webelievewehaveauthoritytodosobecausetoapplyitas '#* writtenwouldproduceabsurdresults. Inenactingthe x)$, classificationstructureinsubpart2,Congresslinkedthe $+t&. severityofanareasairqualityproblemwiththetime  neededtoattainandthestringencyofthecontrolsthatan \ areawouldberequiredtoadopt.Thus,areaswithamore X significantairqualityproblemweregrantedmoretimeto   attaintheNAAQS,butwerealsosubjecttomorestringent `  controls.IfweappliedTable1,aswritten,forpurposes  \  ofthe8hourNAAQS,theclassificationschemewouldnotbe   relatedtotheseverityoftheareas8hourozoneproblem. d   ` If1hourvalueswereusedtoclassify8hour `  nonattainmentareasbasedsolelyonTable1aspresentedin   section181oftheCAA,therewouldbe2seriousareas,9 h moderateareas,and26marginalareas. C  20      ׀Unlikeother d areas,marginalareas(asexplainedelsewhere)arenot  subjecttotherequirementforattainmentplanstoensure l thattheyidentifyandadoptthecontrolsnecessaryfor h attainmentbytheirattainmentdate.BasedonEPAs  modelingprojectionsoffutureozonelevelsandpast p  experienceworkingwithstatesonozoneSIPs,EPAbelieves !l" itisclearthatmostoftheareasthatwouldbemarginalif "$ classifiedby1hourdesignvaluewouldfailtoattainthe  8hourstandardwithoutadditionallocalcontrolsbythe \ spring2007attainmentdateformarginalareas.These X includemajorcitieswithelevated8hourozonelevelssuch   asChicagoandDallasFortWorth.Infact,overaquarter `  oftheseareasthatwouldbemarginalifclassifiedby1  \  hourdesignvalueswerenotprojectedtoattainthe8hour   NAAQSwithoutadditionallocalcontrolsevenby2010.The d  projectionthatmanyoftheseareaswouldnotattainby2010 `  withoutadditionalcontrolsisfurtherevidencetheywould   notattainin2007withoutfurthercontrols.Thus,formany h areas,classifyingby1hourdesignvaluewouldnotreflect d theseverityoftheir8hourozoneproblemorthetime  neededtoattain. l  ` Anadditionalproblemisthatthepracticaleffectof h placingmanyareasthatcannotattainby2007intothe  marginalclassificationwouldbetodelaydevelopmentof p  plansforimprovingairqualitytomeetthe8hourstandard. !l" ThiswouldbeinconsistentwithCongresssintent,reflected "$ intherequirementsoftheAct,thatareasattainair t$& qualitystandardsasexpeditiouslyaspracticable. Rather,  &p!( Congressintendedclassificationstoapproximatethe '#* attainmentneedsofareas.Inthiscircumstance,itis x)$, appropriateforEPAtomake,bywayofregulation,alimited $+t&. modificationtoTable1toreflectCongressionalintent.2XcXX Xc   ` Werecognizethatevenundertheapproachadoptedby \ EPA,someofthesameanomalieswillbecreated.For X example,someareasmayneedmoretimetoattainthan   providedbytheareasinitialclassification.However, `  theseanomaliesaremorelimitedbecausetheclassifications  \  moreappropriatelyrecognizeanareas8hourozoneproblem.   Asnotedaboveinourdiscussiononthebasisforselecting d  Option2,webelievethestatutorymechanismssuchas `  voluntarybumpupscanaddresstheseinequitiesinthe   limitedsituationsinwhichtheyarise.Incomparison ,if h 1hourvalueswereusedtoclassify8hournonattainment d areasbasedsolelyonTable1aspresentedinsection181of  theCAA,therewouldonlybe2seriousareas,9moderate l areas,and26marginalareas.Thisisamuchdifferent h distributionthanusingOption2,inwhichtherewouldbe  moreareasinthehigherclassifications(1severe17,4 p  serious,21moderate)andfarfewer(11)marginalareas. !l" And,undertheadoptedapproach,thedistributionunder "$ subpart2isbasedontheareas8hourdesignvaluenotits t$& 1hourdesignvalue. C  21        &p!( RESPONSETOCOMMENTSFAVORINGOPTION1ARGUINGTHATSUBPART  2WASMORELIKELYTOPRODUCEPROGRESSANDFASTERATTAINMENT: \ # XcXX2Xcf#Othercommentersraisedconcernsthatbecausesubpart1is X lessprescriptivethansubpart2andpotentiallyallows   laterattainmentdatesforthelesspollutedareas,areas `  willnotinfactattainthe8hourNAAQSasquicklyunder  \  subpart1astheywouldberequiredtodoundersubpart2.   Asevidence,thesecommenterspointtothepastfailureof d  areastoattaintheozoneNAAQSpriortotheenactmentof `  subpart2in1990.Wedisagree.2XcXX Xc    ` Subpart1andsubpart2bothrequireareastoattain h the8hourozoneNAAQSasexpeditiouslyaspracticable. d Thus,theintentionoftheCAAisthatregardlessofwhether  anareaiscoveredundersubpart1orsubpart2,itmust l achievecleanaironthesameschedule!i.e.,as h expeditiouslyaspracticable.Inaddition,CAAsection  172(c)(1)requiresthataSIPforanonattainmentarea .. p  .shallprovideforimplementationofallreasonably !l" availablecontrolmeasures[ RACM]asexpeditiouslyas "$ practicable...andshallprovideforattainmentofthe t$& [NAAQS].InreviewingSIPsforapprovabilityundersubpart  &p!( 1,wewillevaluatewhethertheemissioncontrolmeasuresin  theSIPandthetimingofimplementationcomportswiththe \ RACMandattainmentprovisionstoensureallRACMare X adoptedandimplementedasexpeditiouslyaspracticableand   thattheattainmentdateisasexpeditiousaspracticable. `  Subpart1setsaninitialoutsideattainmentdateof5years  \  followingdesignationforthe8hourNAAQS.    ` Subpart2setstheearliestoutsideattainmentdateas d  3yearsfollowingdesignation C  22      ׀formarginalareas.Under `  subpart2,marginalareasarenotrequiredtosubmit   attainmentdemonstrationsand,forallpracticalpurposes, h arenotrequiredtoadoptadditionallocalcontrolsfor d existingsources.j C  23      ׀Thus,ingeneral,Congressanticipated  thattheseareaswouldcomeintoattainmentwithin3years l withoutsignificantadditionallocalcontrols.Webelieve h thatmostareascoveredundersubpart1withairquality  problemssimilartomarginalareaswillinfactcomeinto \ attainmentwiththe8hourNAAQSonasimilartimeframeas X areasclassifiedasmarginal(i.e.,3yearsfollowing   designation). C  24      ׀Infact,webelievetheprospectsfornear `  termattainmentbasedonexistingprogramsaremore  \  favorablenowthantheywerein1990becausenationaland   regionalcontrolprogramsalreadyinplacewillachieve d  substantialreductionsinNOxandVOCemissionspriortoMay `  2007.TheseincludetheregionalNOxSIPCall,which   mandatesinterstatetransportcontrolsforcertainStatesby h May31,2004(63FR53756,October27,1998);progressively d morestringentemissionsstandardsfornewcarsandlight  dutytrucksissuedsince1990,mostrecentlytheTier2 l motorvehicleemissionstandards,andassociatedsulfurin h gasolinerequirements(65FR6698,February10,2000);and  theheavydutydieselrule(66FR5002,January18,2001). p   ` Forareascoveredundersubpart1withanairquality !l" problemsimilartosubpart2moderateareas,thepresumptive "$ maximumattainmentdatewillbe1yearearlier!i.e.,5 t$& yearsfollowingdesignationratherthan6years.Toreceive  &p!( alaterattainmentdate,section172(a)(2)(A)requiressuch '#* areastodemonstratemoretimeisneededbasedonthe x)$, severityofnonattainmentandtheavailabilityand  feasibilityofpollutioncontrolmeasures.Astothefirst \ factor!severityofnonattainment!EPAbelievesthatit X wouldbedifficulttojustifyprovidingaperiodlongerthan   6yearssincesimilarareasclassifiedundersubpart2would `  nothavealongertimetoattain.Thus,suchanareawould  \  needtodemonstratethattheavailabilityandfeasibilityof   controlmeasures(includingthosemandatedundersubpart2) d  wouldjustifyanextensionlongerthan6years.Asimilar `  analysiswouldapplyifanareawithanevenmore   significantairqualityproblemwerecoveredundersubpart h 1.Forthisreason,wedonotbelievethatpublichealth d concernssupportclassifyingallareaswithsimilarair  qualityundersubpart2. l # XcXX2Xc#4. ` Underthefinalclassificationapproach,howwillEPA h classifysubpart1areas?(SectionVI.A.4.ofproposal;68  FR32813;Section51.904ofdraftandfinalrules) p  ! ! (գ8xA8L9;<=>?@a.Background.Section172(a)(1)providesthatEPAhas !l" thediscretiontoclassifyareassubjecttosubpart1.We "$ proposedtwooptionswithrespecttoclassificationsfor t$& areassubjectonlytosubpart1(68FR32813).First,we  &p!( proposedtocreatenoclassifications.Second,weproposed '#* tocreateoneclassification!aninterstateoverwhelming x)$, transportclassificationforareasthatsubmitamodeled $+t&. attainmentdemonstrationshowingtheareasnonattainment  problemisduetooverwhelmingtransportandthatmeetthe \ definitionofaruraltransportareaundersection182(h)of X theCAA.AswenotedintheJune2,2003proposal,thearea   wouldreceiveanattainmentdatethatisconsistentwith `  section172(a)(2)(A),butthattakesintoconsiderationthe  \  following:    `  Theattainmentdateofupwindnonattainmentareas d  thatcontributetothedownwindareasproblem;and `   `  Theimplementationscheduleforupwindarea   controls,regardlessoftheirgeographicscope(e.g., h national,regional,statewide,local). d  ` ThisoptionwouldpartiallyaddressTribalconcerns  aboutdesignationswhereaTribalareadesignated l nonattainmentdoesnotcontributesignificantlytoitsown h problem.ThisisoneofthekeyissuesfortheTribeswho  seektohaveeconomicgrowthfromnewsourceswithintheir p  jurisdictionbutthathavedifficultyobtainingemission !l" reductionoffsetsfromsourceslocatedeitherinsideor "$ outsideTribalareas. t$& b.Summaryoffinalrule.Weareadoptingthesecond  &p!( optionbutmodifiedasaresultofcomments.Weare '#* creatinganoverwhelmingtransportclassificationthatwill x)$, beavailabletosubpart1areasthatdemonstratetheyare $+t&. affectedbyoverwhelmingtransportofozoneandits  precursorsanddemonstratetheymeetthedefinitionofa \ ruraltransportareainsection182(h).However,areas X wouldnothavetodemonstratethattransportwasduesolely   tosourcesfromoutsidetheState(interstatetransport)as `  wasimpliedbytheJune2,2003proposal.Allotherareas  \  thatdonotqualifyfortheoverwhelmingtransport   classificationwouldnotbeclassified.Inaddition,an d  areamayconsidertheeffectsofinternationaltransportof `  ozoneandprecursorsindeterminingiftheareaisaffected   byoverwhelmingtransport. h  ` Anoverwhelmingtransportclassificationwill d accomplishseveralpurposes.Onepurposeistocommunicate  tothepublictheneedforanattainmentdatetoaccountfor l thecontroltimetableforupwindareaswhoseemissionsare h overwhelminglycontributingtotheareasnonattainment  problem. Anareawillbeclassifiedasan"Overwhelming p  TransportArea"uponfullapprovalofanattainment !l" demonstrationSIPthatdemonstrates,usingEPAapproved "$ modeling,thatthenonattainmentproblemintheareaisdue t$& to"overwhelmingtransport,"assetforthinguidance.The  &p!( areamustalsomeetthatpartofthedefinitionofarural '#* transportareainsection182(h)thatrequiresthatanarea x)$, notbeinoradjacenttoaConsolidatedMetropolitan $+t&. StatisticalArea(CMSA).   ` Inapprovinganattainmentdateforthearea,EPAwill \ consider:(1)theattainmentdateoftheupwind X nonattainmentareaorareasthatcontributetothedownwind   areasproblem;and(2)theimplementationschedulefor `  upwindareacontrols,regardlessoftheirgeographicscope  \  (e.g.,national,regional,statewide,local).    ` IntheJune2003proposal,weproposedthatsuchareas d  wouldbesubjecttorequirementssimilartothosethatapply `  toareasclassifiedasmarginalundersubpart2.Weare   consideringthecommentswereceivedontheissueof h applicablerequirementsforthesesubpart1areasandwill d addressthisissueafterweissueguidanceonassessmentof  overwhelmingtransport. l  ` Inaddition,theproposedrulealsoindicatedthatwe h couldconsidermoreflexibilityforconformityforsuch  areas.Inourproposedtransportationconformityrule p  publishedonNovember5,2003(68FR62690),wedidnot !l" proposeanyspecificconformityflexibilityforareas "$ affectedbyozonetransport.However,manyoftheproposed t$& options,includingthetypesofemissionstestsusedin  &p!( conformity,wouldbeavailabletoareasaffectedby '#* transport,aswellasothertypesof8hourozoneareas.In x)$, addition,theexistingtransportationconformityrule $+t&. alreadyprovidesflexibilityinsuchthingsas  transportationmodelingrequirementsforsmallerareaswith \ lessseverelocalairqualityproblems.Also,EPAintends X toproposeinafewmonthsmoreflexibleNSRprovisionsthat   wouldapplyinsuchareas. `   ` Webelievetheoverwhelmingtransportclassification  \  forareascoveredundersubpart1isconsistentwiththeCAA   andisreasonable.Webelievethattheclassification d  shouldberestrictedtoruralareasbecausetheseareaswill `  generallynothavesignificantsourcesofemissionsto   controlandthereforearenotlikelytocontributemuchto h theirownnonattainmentproblem.Thereareexceptions,of d course,suchasruralareaswithlargesourcessuchaspower  plants,butsuchareaswouldalsoneedtomeettheother l criteriafortheclassification,suchasnotcontributing h significantlytononattainmentinotherareas.   ` Indetermininganattainmentdateforareasclassified p  as transport,wewouldapplythecriteriainsection !l" 172(a)(2)(A).Thesecondcriterioninsection172(a)(2)(A) "$ !theavailabilityandfeasibilityofcontrolmeasures! t$& willallowEPAtoconsidertheeffectsoftransported  &p!( pollutioninsettinganappropriateattainmentdatefor '#* theseareasofnolaterthan10yearsfollowingdesignation. x)$,  ` Werecognizethattheremaybeareasaffectedby $+t&. transportthatdontmeetthedefinitionofruraltransport.  However,indeterminingattainmentdatesforareasunder \ section172(a)(2)(A),wecanconsidertheavailabilityand X feasibilityofcontrolmeasures;thus,areasthatdonot   meetthedefinitionofaruraltransportareashouldbeable `  toadoptanattainmentdatethatreflectsthetimeperiod  \  forreductionsinupwindareasthatarecontributingto   nonattainment. d   ` TheEPAdecidednottoexerciseitsdiscretionto `  createadditionalclassificationsforsubpart1areas.2XcXX XcWe   donotbelieveanotherclassificationisnecessaryfor h expeditiousattainmentofthe8hourNAAQSfortheseother d subpart1areas.   ` Thefinalrule(section51.904(a))providesfora l subpart1areatobeclassifiedasanoverwhelmingtransport h areaifitmeetsthecriteriaasspecifiedforrural  transportareasundersection182(h)oftheCAAand p  overwhelmingtransportguidancethatwewillissueinthe !l" future.AlthoughEPAsJune2,2003noticereferencedan "$ EPAguidancedocumentasthecriteriafordeterminingthe t$& contributionofsourcesinoneormoreotherareasarean  &p!( overwhelmingcauseofanareabeingdesignated '#* nonattainment,webelievethatguidanceneedstobeupdated. x)$, Thus,weareretractingourpreviousguidanceandwillissue $+t&. revisedguidance.Weplantoaddresscontrolrequirements  applicabletotheseareasinPhase2. \ c.Commentsandresponses   p  X COMMENT:# XcXX2Xc=#Mostofthecommenterswhocommentedon   classificationsforsubpart1areasobjectedtothe `  requirementthattoreceiveanoverwhelmingtransportarea  \  classificationanareamustdemonstratethatitisarural   transportarea.Manyofthesecommenterspointedoutthat d  thereareanumberofareasthatdonotmeetthatdefinition `  andthatdonotgenerateasignificantportionofemissions   thatcontributetotheareasnonattainmentproblem.2XcXX XcԀSome h alsostatedthattheCAAdoesnotmandatethisasa d criterionandthusthetestwasundulyrestrictive.These  commentersaskedthattheavailabilityoftheoverwhelming l transportclassificationbebasedonlyonwhetheranareais h avictimofoverwhelmingtransport.  RESPONSE:# XcXX2Xc7E#TheCAAdoesnotmandatethatanareabe p  consideredruralinordertoreceiveanoverwhelming !l" transportclassificationundersubpart1.However,we "$ believethatareasthatarenotrural,eveniftheyare t$& affectedtoasignificantdegreebytransport,ingeneral  &p!( contributeatleastsomedegreetotheirownandlikelyto '#* otherareasnonattainmentproblems.Thefinalrule, x)$, therefore,isasproposed!theoverwhelmingtransport $+t&. classificationisonlyavailabletoareasthatmeetthe  criteriaforruraltransportareasundersection182(h)of \ theCAA. X COMMENT:OnecommentersuggestedEPAprovideincreased   flexibilityforareasthatwouldbeclassifiedas `  nonattainment,primarilyforreasonsrelatedtotransport.A  \  specialcategoryfortransportareas,shouldbecreatedfor   areasthatareinattainmentofthe1-hourstandardbut,if d  notfortheimpactoftransport,wouldnotbeinviolation `  ofthenew8-hourstandard.Theregulatoryrequirementsfor   transportareashouldbeminimalandrequiredcompliance h datesshouldextendoutatleastaslongastheupwind d states.  RESPONSE:Wenotethat8-hourozonenonattainmentareas l coveredundersubpart1generallywillbeclosetoattaining h the1-hourstandard.Webelievethecriteriausedto  determineoverwhelmingtransportwillinvariablyresultina p  situationwhereanareasubjecttooverwhelmingtransport !l" wouldbeinattainmentofthestandardbutfortransport. "$ Subpart1providesamaximumof10yearsfromtheeffective t$& dateofnonattainmentdesignationforattainment.Wenote,  &p!( however,thatifsuchanareabelievesthatitwouldneedan '#* attainmentdatelongerthan10years,itcouldrequesttobe x)$, reclassifiedundersubpart2toaclassificationwitha $+t&. longerattainmentdate.Theareawould,ofcourse,haveto  meettherequirementsofitssubpart2classification \ (eitheritsrequestedclassificationortheruraltransport X classificationifitsoqualifies).2XcXX Xc   5. ` WillEPAadjustclassifications?(SectionVI.A.9.of `  proposal;68FR32816;section51.903(b)and(c)offinal  \  rule)   a.Background.Undersections181(a)(4)and181(b)(3),an d  ozonenonattainmentareamaybereclassifiedtothenext `  higherorlowerclassification.Section181(a)(4)ofthe   CAAstates: h 0 ` Ifanareawouldhavebeenclassifiedinanother d categoryifthedesignvalueintheareawere5percent : greateror5percentlessthanthelevelonwhichsuch  classificationwasbased,theAdministratormay,inthe  Administrator'sdiscretion,within90daysafterthe l initialclassification,adjusttheclassificationto B placetheareainsuchothercategory.Inmakingsuch h adjustment,theAdministratormayconsiderthenumber > ofexceedancesofthenationalprimaryambientair  qualitystandardforozoneinthearea,thelevelof  pollutiontransportbetweentheareaandotheraffected p  areas,includingbothintrastateandinterstate F ! transport,andthemixofsourcesandairpollutantsin !l" thearea.!B#` (#` (# rS ` Section181(b)(3)requirestheAdministratortogrant #% therequestofanyStatetoreclassifyanonattainmentarea J% ' intheStatetoahigherclassification.   &F") b.Summaryoffinalrule.Weareadoptingtheapproachwe (#+ includedintheproposal.Forareassubjecttosubpart2, N*%- section181(a)(4)oftheCAAprovidesthatclassifications +J'/ maybeadjustedupwardordownwardforanareaiftheareas  designvalueiswithin5percentofanotherclassification. \ If,forexample,anareaissubjecttoasubpart2 X classificationandthereisevidencethattheareawillnot   benefitsignificantlyfromlocalcontrolsmandatedby `  subpart2fortheareasclassificationandcanattain  \  withinthetimeperiodspecifiedforthenextlower   classification,theareamayobtainsomereliefbasedonthe d  5percentruleintheCAAifapplicable.Inaddition, `  section181(b)(3)requirestheAdministratortograntthe   requestofanyStatetoreclassifyanonattainmentareain h theStatetoahigherclassification.# XcXX2XceQ#2XcXX Xc d  ` Section51.903wasrevisedfromtheinitialdraft  regulatorytextlanguagetoaddthereclassification l provisionsinsection181(a)(4)and181(b)(3). h c.Commentsandresponses  COMMENT:Severalcommenterssupportedtheuseofprovisions p  insection181(a)(4)toallowadjustmentofa !l" classification.Commentsindicatedthatthisapproachcould "$ resultincostsavingsincaseswheretheincreasedcontrols t$& ofthehigherclassificationwouldnotbeneededfor  &p!( attainment. OnecommenternotedthattheAdministrator '#* shouldconsiderseveralfactorsinmakingtheadjustment x)$, undersection181(a)(4),includingthenumberofexceedances $+t&. oftheNAAQSandcomplexityoftheproblem.Thecommenter  requestedthatEPAexplainhowtheAdministratorwouldmake \ thisdecisionandtheprocessthatwillbeused.Another X commenterrecommendedthattheactualtestofcompliance   withtheprovisionsofsection181(a)(4)shouldinclude `  allowanceformeteorologicalfluctuationinordertoavoid  \  Stateshavingtomeetanaveragedesignvaluewellbelowthe   NAAQSbeforedeemedincompliance. d   RESPONSE:TheEPAsguidanceonthe5percentbumpdown `  provisioninsection181(a)(4)iscontainedintheNovember   6,1991FederalRegister(56FR56698)whichestablishedthe h initialdesignationsandclassifications.Inaseparate d FederalRegisternotice,EPAwillinviteStatestosubmit  bumpdownrequests.TheEPAwilldescribethecriteria l (includinganychangesfromthe1991criteria)forapproval h of5percentbumpdownsinthatnoticeandwillprovideat  leasta30dayperiodforStatestosubmittheirrequests. p  Section181(a)(4)authorizestheAdministratortoadjusta !l" classificationwithin90daysaftertheinitial "$ classification.TheEPAcontinuestobelieve,asprovided t$& intheJune2,2003proposal,thatsection181(a)(4)does  &p!( notprovideabasisforanareatomovefromsubpart2to '#* subpart1.  x)$,  # XcXX2Xc]#2XcXX Xc6.Proposedincentivefeature(SectionVI.A.6.of $+t&. proposal;see68FR32815;51.903(b)ofdraftrule)  a.Background.Intheproposedrule(68FR32815# XcXX2Xcg#2XcXX Xc),we \ soughtcommentonaclassificationfeaturethatwouldallow X areasclassifiedundersubpart2toqualifyforalower   classificationuponademonstrationtheareawouldattain `  the8hourNAAQSbytheearlierattainmentdateofalower  \  classification.Forexample,anareathatwouldbe   classified"moderate"basedonits8hourdesignvaluewould d  qualifyfora"marginal"classificationbydemonstratingit `  wouldattainthe8hourNAAQSwithin3yearsofdesignation.   b.Summaryoffinalrule.Wearenotincludingthe h proposedincentivefeatureinthefinalrule.Wereceived d numerousadversecommentsontheidea,raisingbothlegal  andpolicyissues.Becauseweagreeasapolicymatterthat l weshouldnotadopttheincentivefeature,wedonotreach h thelegalissueofwhetherthestatutegrantssuch  authority.Ourbasisforthisdecisionisprovidedmore p  fullyintheRTCdocument,portionsofwhichareexcerpted !l" below.Inshort,webelievethatonlyafewareaswould "$ havebenefittedfromthisproposalconsideringthe t$& flexibilityalreadyavailableunderclassificationOption2,  &p!( andwebelievethatthedifficultiesindevelopingand '#* implementingsuchanapproachoutweighanybenefits.In x)$, particular,commentersontheJune2,2003proposalwere $+t&. concernedthatwedidnotidentifythetypeofmodelingthat  areascouldrelyontotakeadvantageofthisoption.While \ wehadnotidentifiedintheJune2,2003proposalthetype X ofmodelingthatcouldbeused,wehadreferencedour   currentmodelingguidanceinthedraftregulatorytextwhich `  waspublishedonAugust6,2003.Additionally,webelieve  \  itwouldbeverydifficultforanareatohavecompletedthe   necessarymodelingandforustoapprovesuchaSIP d  submissionmuchinadvanceoftheattainmentdatefora `  marginalarea.Further,iftheareadidnotmeetthat   attainmentdate,itwouldneedtobeginthemodelingprocess h overagainalmostimmediately.Wenowbelievethatitmakes d moresensefortheareatopreparethemodelingrequiredfor  itshigherclassificationand,iftheareaattainstheNAAQS l earlierthantheattainmentdateforitsclassification,our h CleanDataPolicy C  25      ׀willproviderelieffromRFP  requirements. p  c.Commentsandresponses   p  !l" COMMENT:Abouthalfthecommentersthataddressedthis "$ issueopposedtheincentivefeature.Thesecomments t$& originatedmainlyfromenvironmentalorganizationsandsome  Stateandlocalairpollutioncontrolagenciesand \ organizations.Manyofthesecommentersquestionedthe X legalbasisforsuchafeatureandalsobelievedmodelingis   tooinaccurateorunreliabletobeusedforclassification `  purposes.Theybelievedthatmonitoringdatashouldbethe  \  solebasisforclassifications.Theothercommentsreceived   onthisissuesupportedtheincentivefeature.These d  commentsoriginatedmainlyfromindustrialrepresentatives `  andorganizations,aswellasseveralStateandlocalair   agenciesandtransportationagenciesandorganizations. h RESPONSE:Ouranalysisindicatesthattheincentivefeature d wouldnothavehelpedverymanyareas.Of21hypothetical  nonattainmentareasclassifiedasmoderate(basedon l 2000-2002airqualitydata),ourmodelingprojectsthatonly h 3wouldhavequalifiedwithoutfirstadoptingfurther  controls.Noseriousorhigherclassifiedareawouldhave p  qualifiedwithoutfurthercontrols.Veryfewareaswould !l" evenreceiveaclassificationhigherthanmoderate.In "$ addition,evenifweadoptedthisapproach,wedonot t$& believetherewouldhavebeenenoughtimeforareasseeking  &p!( amarginalclassificationtosubmitaplanwithlocal '#* controlsthatdemonstrateattainmentbyaSpringattainment x)$, datein2007andimplementthecontrolsbytheSpringof $+t&. 2006.Inaddition,wewouldhavetodevelopguidancefor  thedemonstration.Furthermore,althoughmanycommenters \ supportedhavingthefeature,manyothercommentersobjected X tothefeatureonanumberofgrounds.Becauseofthe   difficultiesinvolvedinadministeringsuchaprogram,the `  unfavorabletiming,andtheanticipatedlownumberofareas  \  thatcouldbenefitfromthefeature,wearenot   incorporatingthefeatureinthefinalrule. d   ` Anumberofcommenterswhoopposedthefeature `  contendedthattheapproachwasnotsupportedbytheCAA.   Sincewearenotadoptingthefeatureinthefinalruleon h policygrounds,wedonotaddressthelegalissueshere. d # XcXX2Xch#B. ` HowwillEPAtreatattainmentdatesforthe8hour  ozoneNAAQS?(sectionVI.B.ofproposal;see68FR32816; l 51.903and51.904draftandfinalrules) h 1. ` Background.UnderSubpart2oftheCAA,maximum  attainmentdatesarefixedasafunctionofanonattainment p  areasclassificationunderTable1.TheCAAprovidesthat !l" anareasattainmentdatemustbe asexpeditiousas "$ practicablebutnolaterthanthedateprovidedinTable1 t$& forthatareasclassification.Thestatutorydatesare  &p!( specifiedasasetnumberofyearsfromthedateof '#* enactmentoftheCAAAmendmentsof1990.Sinceastrict x)$, applicationofTable1wouldproduceabsurdresultsformost $+t&. areas(i.e.,areasclassifiedasmarginalwouldhavea  November15,1993attainmentdate,moderateareaswouldhave \ aNovember15,1996attainmentdate,etc.),weare X promulgatingatargetedrevisionofTable1toreflect   attainmentdatesconsistentwithCongressionalintent. `   ` WhiletheattainmentdatesinTable1areexpressly  \  linkedtothedateofenactmentoftheCAAAmendmentsof   1990,thisisalsothedateonwhichmostareaswere d  designatedandclassifiedasamatteroflaw.Inaddition, `  asexplainedinthepreambletotheproposedrule(68FR   32817),otherprovisionsoftheCAAspecifythatthedate h forattainmentshallrunfromthedateofdesignationand/or d classificationasamatteroflawforanarea.Consistent  withthis,weproposedthatthestartingpointfortheset l timeframesforattainmentwouldbethedateanareais h designatedandclassifiedforpurposesofthe8hour  NAAQS. C  26      ׀Thus,forexample,anareaclassifiedasmarginal p  forthe8hourNAAQSwouldhaveupto3yearsfrom !l" designationtomeetthatNAAQSandamoderateareawould "$ haveupto6yearsfromdesignationtoattain. t$&  ` Forareascoveredundersubpart1,attainmentdatesare  &p!( setundersection172(a)(2)(A),whichprovidesthattheSIP  mustdemonstrateattainmentasexpeditiouslyaspracticable \ butnolaterthan5yearsafterdesignation,withupto10 X yearsafterdesignationpermittediftheseverityofthe   areasairpollutionandtheavailabilityandfeasibilityof `  pollutioncontrolmeasuresindicatemoretimeisneeded.In  \  thedraftregulatorytext,weprovidedthatEPAwould   establishtheattainmentdateforanareaatthetimewe d  approvetheareasattainmentdemonstration.  `  2.Summaryoffinalrule.Weareadoptingthetimeperiods ( forattainmentthatweproposedforareasunderbothsubpart  1andsubpart2oftheCAA.Forareassubjecttosubpart2 0 oftheCAA,themaximumperiodforattainmentwillrunfrom , theeffectivedateofdesignationsandclassificationsfor  the8hourNAAQSandwillbethesameperiodsasprovidedin 4 Table1ofsection181(a): 0 ec  ecV"0 `   Marginal!3years,ecVq݌ ` (#` (# Ќ  ec  ec"0 `   Moderate!6years,ec݌8!"` (#` (# Ќ  ec  ec"0 `   Serious!9years,ec݌"4$` (#` (# Ќ  ec  ec;"0 `   Severe!15or17years,andec;V݌$&` (#` (# Ќ  ec  ec"0 `   Extreme20years.ec݌<&!(` (#` (# Ќ  Weareadoptingthisapproachbecauseapplyingthetable,as '8#* written,wouldproduceabsurdresults.Forthereasons )$, aboveanddiscussedinthepreambletotheproposedrule,we @+&. believeitisconsistentwithCongressionalintenttobegin  thetimeperiodsforattainmentspecifiedinTable1in \ section181(a)atthetimeofdesignationand X classification.    ` Consistentwithsection172(a)(2)(A),forareassubject `  tosubpart1oftheCAA,theperiodforattainmentwillbe  \  nolaterthan5yearsaftertheeffectivedateofthe   designation.However,EPAmaygrantanareaanattainment d  datenolaterthan10yearsafterdesignation,ifwarranted `  basedonthefactorsprovidedinsection172(a)(2)(A).The   EPAwillestablishanattainmentdateforeachsubpart1 h areaatthetimeweapproveanattainmentdemonstrationfor d thearea.  3. ` Commentsandresponse l COMMENT: SeveralcommentersreiteratedtheCAAs h requirementthatareasattaintheNAAQSas expeditiouslyas  practicable.Theyfeltthattheattainmentdeadlinesin p  theproposedrulewouldimpedetheprogressthatareashave !l" madeandwouldsubjectthegeneralpublictoyearsof "$ unhealthyairquality.OnecommentersuggestedthatEPA t$& createenforceableshort-termcompliancedatestoassure  &p!( citizensofdownwindStatesthatupwindStatesaremeeting '#* theirlonger-termcompliancedeadlines.Othercommenters x)$, feltthattheattainmentdatesunderbothsubpart1and2 $+t&. thatwereproposeddidnotprovideenoughtimeforareasto  attainforanumberofreasons,suchas:areaswouldnotbe \ abletotakecreditforemissionsreductionsfromFederal X measures,theslowturnoverofmobilesourcefleetswould   notachievetheneededmobilesourcereductionsinthe `  timeframesproposed,EPAsClearSkiesmodelingshowsthata  \  numberofareasinthemid-Atlanticandnortheastwillnot   comeintoattainmentbeforethemiddleofthenextdecade, d  itwouldnotbefeasibletohavestationaryandmobile `  sourcecontrolsinplace3yearsbeforetheattainmentdates   forpurposesofmonitoring,etc.However,anumberof h commentersagreedwithEPAsproposaltoestablish d attainmentdatesthatcorrespondtothetimeframes  establishedundersubpart2oftheCAAfromthedateof l 8-hournonattainmentdesignations.Inaddition,one h commenterstatedthattheproposaldidnotclearlyaddress  howattainmentdatesforsubpart1areaswouldbeset. p  Finally,severalcommentersrecommendedthatEPAchangethe !l" attainmentdatestoNovemberorDecemberoftheattainment "$ yearratherthaninAprilsoareascanusetheozoneseason t$& airqualitydatafromtheattainmentyeartodemonstrate  &p!( attainment. '#* RESPONSE:AsstatedinourJune2,2003proposal,under x)$, subpart2oftheCAA,maximumattainmentdatesarefixed_as $+t&. afunctionofa_nonattainment_Ԁareasclassificationunder  Table1.TheCAAprovidesthatanareasattainmentdate \ mustbe asexpeditiousaspracticablebutnolaterthan X thedateprescribedinTable1forthatareas   classification.Thedateswerespecifiedasthenumberof `  yearsfromthedateofenactmentoftheCAAAmendments,  \  whichwasNovember15,1990,whichwasalsothedateof   designationandclassificationbyoperationoflawformost d  subpart2areas.Webelievethatapplyingtheattainment `  datesasexpresslyprovidedunderTable1wouldproduce   absurdresults,sinceastrictapplicationofTable1would h resultinanattainmentdateofNovember15,1993for d marginalareasandanattainmentdateofNovember15,1996  formoderateareas.Althoughwebelieveastrict l applicationofthestatutewouldproduceabsurdresults,we h donotbelievethatallowsbroadauthoritytorewritethe  statute.Rather,welooktothelegislativehistoryand p  otherprovisionsoftheCAAtodiscernCongressionalintent. !l" Consequently,forthereasonsprovidedaboveandinthe "$ preambletotheproposedrule,wehavedeterminedthat t$& attainmentdateswillrunfromtheeffectivedateof  &p!( designationsandclassificationsforthe8-hourozone_NAAQS_. '#* Sincewearedesignatingandclassifyingareasforthe x)$, 8-hourozone_NAAQS_ԀwithaneffectivedateofJune15,2004, $+t&. thecorrespondingattainmentperiodswouldrunfromJune15,  2004. \  ` Wedonotbelievewehaveauthoritytochangethe X attainmentdatestoNovemberorDecemberoftheattainment   yearasseveral_commenters_Ԁrequested.Webelievethat `  Congresswouldhaveintendedforareasdesignated  \  _nonattainment_Ԁandclassifiedundersubpart2forthe8-hour   _NAAQS_Ԁtohaveattainmentperiodsconsistentwiththosein d  Table1(e.g.,3yearsformarginalareas,6yearsfor `  moderateareas,etc.)Thiswouldresultinthe8-hour   marginalattainmentdatebeing3yearsfromtheeffective h dateofdesignationsforthe8-hour_NAAQS_Ԁ(i.e.,June15, d 2007),themoderateattainmentbeing6yearsfromthe  effectivedateofdesignationsforthe8-hour_NAAQS_Ԁ(i.e., l June_15,_Ԁ2010),etc. h  ` Additionally,EPAdoesnothavetheauthorityto  shortenattainmentdatesorlengthenattainmentdatesto p  allowareastotakecreditforemissionsreductionsfrom !l" futureFederalorregionalmeasuresasseveral_commenters_ "$ suggested.Thestatuteprovidesforallareastoattainas t$& expeditiouslyaspracticable.Aspartofitsattainment  &p!( demonstration,aStatemustdemonstratethatthereareno '#* reasonablyavailablecontrolsthatcanexpediteattainment. x)$, Therefore,Statesmustaddresswhytheycannotattain $+t&. _earlierthanthemaximumattainmentdate.Astolonger  attainmentdates,Statesmayrequestavoluntarybumpupif \ theybelieveanareacannotattainbyitsmaximumstatutory X attainmentdatethroughtheadoptionofRACM.    ` Forareasclassifiedundersubpart1,attainmentdates `  willbesetundersection172(a)(2)(A),whichprovidesthat  \  theSIPmustdemonstrateattainmentasexpeditiouslyas   practicablebutnolaterthan5yearsafterdesignationor d  10yearsafterdesignationiftheseverityoftheareasair `  pollutionandtheavailabilityandfeasibilityofpollution   controlmeasuresindicatemoretimeisneeded.Under h subpart1,wewillestablishanattainmentdateforanarea d atthetimeweapproveanattainmentdemonstrationforthe  area.TheStatemustsupportthattheattainmentdateis l expeditiouslyaspracticableandmustjustifyanyattainment h datelaterthan5yearsusingthefactorsinsection  172(a)(2)(A).Theattainmentdatewillbethedateinthe p  approvedSIP.Thus,ifanareasubmitsanapprovable !l" attainmentdemonstrationshowingthattheycanattainthe "$ 8-hourNAAQSin,e.g.,4years,theareasattainmentdate t$& willbe4yearsfromtheeffectivedateofdesignationsfor  &p!( the8-hourNAAQS. '#* 4.HowwillEPAaddresstheprovisionregarding1year x)$, extensions?(sectionVI.B.2ofproposedrule;68FR32817; $+t&. sections51.907ofdraftandfinalrules)   (88a.Background.Inlimitedcircumstances,bothsubpart1 \ andsubpart2oftheCAAprovidefortwobriefattainment X dateextensionsforareasthatdonotattainbytheir   attainmentdate.Section172(a)(2)(C)ofsubpart1(which `  appliesforallNAAQS)providesforEPAtoextendthe  \  attainmentdateforanareaby1yeariftheStatehas   compliedwithallrequirementsandcommitmentspertainingto d  theareaintheapplicableimplementationplanandnomore `  thanaminimalnumberofexceedancesoftheNAAQShas   occurredintheareaintheattainmentyear.Uptotwo1 h yearextensionsmaybeissuedforasinglenonattainment d area.   ` Section181(a)(5)ofsubpart2containsasimilar l provisionfortheozoneNAAQS,butinsteadofprovidingfor h anextensionwheretherehasbeena minimalnumberof  exceedances,itallowsanextensiononlyifthereisnomore p  thanoneexceedanceoftheNAAQSintheyearprecedingthe !l" extensionyear.Thelanguageinsection181(a)(5)reflects "$ theformofthe1hourozoneNAAQS,whichisexceedance t$& basedanddoesnotreflectthe8hourozoneNAAQS,whichis  &p!( concentrationbased. C  27      ׀Weproposedthatsincesection '#* 181(a)(5)doesnotreflecttheformofthe8hourNAAQSand  applicationwouldproduceanabsurdresult,itwas \ reasonabletointerpretthisprovisioninamanner X consistentwithCongressionalintent,butreflectingthe   formofthe8hourNAAQS.Inaddition,weproposedtoapply `  thetestinsection172(a)(2)(C),whichappliestoareas  \  subjecttosubpart1,inthesamemannerasweapplythe   testundersection181(a)(5)forareassubjecttosubpart2. d  Specifically,weproposedthatanareawouldbeeligiblefor `  thefirst1yearextensionundersection172(a)(2)(C)and   under181(a)(5)if,fortheattainmentyear,theareas4th h highestdaily8houraverageis0.084ppmorless.Thearea d willbeeligibleforthesecondextensioniftheareas4th  highestdaily8hourvalue,averagedoverboththeoriginal l attainmentyearandthefirstextensionyear,is0.084ppm h orless.  b. ` Summaryoffinalrule.Weareadoptingthe \ interpretationthatweproposedonJune2,2003.Underboth X sections172(a)(2)(C)and181(a)(5),anareawillbe   eligibleforthefirstofthe1yearextensionsunderthe8 `  hourNAAQSif,fortheattainmentyear,theareas4th  \  highestdaily8houraverageis0.084ppmorless.Thearea   willbeeligibleforthesecondextensioniftheareas4th d  highestdaily8hourvalue,averagedoverboththeoriginal `  attainmentyearandthefirstextensionyear,is0.084ppm   orless. h  ` Webelievethatitwouldbeabsurdtoapplysection d 181(a)(5)aswrittenforpurposesofthe8hourozoneNAAQS.  Thissectionwaswrittenwiththeformofthe1hourNAAQS l inmind.Forpurposesofthe1hourNAAQS,anareais h violatingtheNAAQSifithasmorethanthreeexceedancesof  theNAAQSatamonitorovera3yearperiod.Thus,ifan p  areaisaveragingmorethanoneexceedanceperyearata !l" monitor,itisviolatingtheNAAQS.Forthe1hourNAAQS, "$ itmakessensetoconsiderwhethertherehasbeenmorethan t$& oneexceedanceintheattainmentyearforpurposesof  &p!( grantinganextensionbecausetwoormoreexceedances '#* indicateasignificantlikelihoodtheareawillnotbeable x)$, toattaintheNAAQSwitha1yearextensionofthe $+t&. attainmentdatesincefourexceedancesovera3yearperiod  meantheareaisviolatingtheNAAQS. \  ` Forthe8hourNAAQS,violationsaredeterminedbased X ontheconcentrationasdeterminedbyaveragingthe4th   highestreadingatamonitorovera3yearperiod.Thus, `  foreachmonitor(withcompletedata),thefourthhighest  \  readingsforeachof3consecutiveyearsareaveragedto   determinewhetheranareaisviolatingtheNAAQS.Ifthe d  averageofthosereadingsisatorabove0.085,thenthe `  areaisviolatingthe8hourozoneNAAQS.Unlikethe1hour   NAAQS,anareacouldhaveseveralexceedancesofthe8hour h NAAQSintheattainmentyearandstillbeontracktoattain d theNAAQSthefollowingyearsinceattainmentisbasedonan  averageofthefourthhighestreading.Forthisreason,and l asweproposed,webelieveitmakessensetoallowforthe h two1yearattainmentdateextensionsundersection  181(a)(5),basedonthe4thhighestreadingatamonitor p  ratherthanbasedonthenumberofexceedances.Weare !l" interpretingthephrase minimalnumberofexceedancesin "$ section172(a)(2)(C)toapplyinthesamemanner. t$& c.Commentsandresponse  &p!( COMMENT:ThecommentersgenerallysupportedEPAsproposed '#* interpretationforgrantinguptotwo1-yearattainmentdate x)$, extensions.Onecommenterrequestedclarificationthatthe $+t&. 4thhighestdailyaverage8-hourozoneconcentrationwould  beusedtograntthefirstextensionandthe4thhighest \ dailyaverage8-hourozoneconcentrationoftheattainment X yearandfirstextensionyearwouldbeusedtodetermine   eligibilityforthesecond1-yearattainmentdateextension. `  Thecommenterfurtherexpressedsupportforthisapproach  \  sinceitisconsistentwithhowEPAdetermineswhetheran   areaisviolatingthe8-hourNAAQS. d  RESPONSE:NocommentersopposedthisaspectofEPAs `  proposal.However,wearerestatingthatthe4thhighest   dailyaverage8-hourozoneconcentrationwouldbeusedto h grantthefirst1yearextensionandthe4thhighestdaily d average8hourozoneconcentrationoftheattainmentyear  andfirstextensionyearwouldbeusedtodetermine l eligibilityforthesecond1yearattainmentdateextension. h C.HowwillEPAimplementthetransitionfromthe1hourto  the8hourNAAQSinawaytoensurecontinuedmomef  nf  g tumin p  Stateseffortstowardcleanerair?(SectionVI.C.ofthe !l" proposal;see68FR32818;51.905ofdraftrule) "$  ` TherearetwokeyissuesthatEPAconsideredtogether t$& regardingthetransitionfromthe1hourNAAQStothe8hour  &p!( NAAQS:(1)whenwillthe1hourNAAQSnolongerapply(i.e., '#* be revoked);and(2)whatprotectionsareinplaceto x)$, ensurethat,oncethe1hourNAAQSisrevoked,airquality $+t&. willnotdegradeandthatprogresstowardattainmentwill  continueasareastransitionfromimplementingthe1hour \ NAAQStoimplementingthe8hourNAAQS.Asintheproposed X rule,thesecondkeyissuehasthreecomponents:(1)what   requirementsthatappliedbasedonanareasclassification `  forthe1hourNAAQSmustcontinuetoapplytothatarea;  \  (2)forhowlong;and(3)inwhatgeographicarea.Below,   2XcXX Xcwesetforthourfinaltransitionapproachinfourparts: d  (1)whenwillthe1hourNAAQSnolongerapply(i.e.,when `  willitberevoked);(2)what1hourobligationsshould   continuetoapplyoncethe1hourNAAQSisrevoked;(3)how h longshouldthoserequirementscontinuetoapply;and(4) d whatisthegeographicareasubjecttotherequirement?  1.f  g f  g f  g f  g WhenwillEPArevokef  g Ԁthe1hourNAAQS?# XcXX2XcW#Ԁ(section l VI.C.2.ofproposal;see68FR32819;section50.9.b.of h proposedandfinalrules)  a.Background.Intheproposedrule(68FR32819),EPA p  providedanindepthdiscussionofthebackgroundofthe !l" transitionrule(40CFR50.9(b))andpolicyasestablished "$ inJuly1997andassubsequentlyrevisedinresponsetothe t$& ongoinglitigationoverthe8hourozoneNAAQSandcourt  &p!( decisions(68FR3281819).Inshort,atthetimethe8 '#* hourNAAQSwaspromulgatedin1997,EPAanticipatedthat x)$, areaswouldimplementthe8hourozoneNAAQSundersubpart $+t&. 1.Areasthatwerenotmeetingthe1hourNAAQSwere  obligatedtocontinuetomeetthatNAAQSandwouldremain \ subjecttomostoftherequirementsthatappliedduetothe X areas1hourclassification,includingobligationsunder   subpart2(62FR38873).AlthoughEPAconcludedinthe `  NAAQSrulemakingthatthe1hourNAAQSwasnotnecessaryto  \  protectpublichealthandthatthe8hourNAAQSwould   replacethe1hourNAAQS(62FR38863),wedeterminedto d  delayrevocationofthe1hourNAAQSforareasnotyet `  meetingthatNAAQSinordertofacilitatecontinued   implementationofthe1hourobligations(62FR38873). h Thus,wepromulgatedaruleprovidingforthephaseoutof d the1hourozoneNAAQSonanareabyareabasisbased2XcXX Xcupona  determinationbyEPAforeachareathatithadmetthe1 l hourNAAQS(40CFR50.9(b),aspromulgatedat62FR38894) h ( revocationrule).   ` Subsequently,becausethependinglitigationoverthe p  8hourNAAQScreateduncertaintyregardingthe8hourNAAQS !l" andourimplementationstrategy,weplacedtwolimitations "$ onourauthoritytoapplytherevocationrule:(1)the8 t$& hourNAAQSmustnolongerbesubjecttolegalchallenge,and  &p!( (2)itmustbefullyenforceable. C  28      ׀(65FR45182,July20, '#* 2000).   ` Ultimately,theSupremeCourtstruckdownthe \ implementationstrategyprovidedforinthepreambletothe X finalNAAQSrule.AlthoughtheCourtagreedwithEPAs   conclusionthatthestatutewasambiguousastohowa `  revised,morestringentozoneNAAQSshouldbeimplemented,  \  theCourtfoundunreasonabletheimplementationstrategyEPA   anticipatedatthetimethe8hourNAAQSwaspromulgated. d  BecauseEPAbelievesthetimeatwhichthe1hourNAAQS `  shouldnolongerapplyisinextricablylinkedtotheoverall   implementationstrategy,EPAdeterminedthatitshould h reconsider40CFR50.9(b)inthecontextofthisrulemaking. d (68FR3281819).# XcXX2Xc#2XcXX Xc   ` ConsistentwiththedecisionoftheSupremeCourt,our l proposedJune2003implementationruleanticipatedthat h some,ifnotall,8hourozonenonattainmentareaswould  implementthatNAAQSundersubpart2oftheCAA.Therewas p  nolongertheclearcutdichotomythatweanticipatedin !l" 1997!i.e.,that8hourimplementationwouldoccurunder "$ subpart1and1hourimplementationwouldcontinuetooccur t$& undersubpart2.Thus,theapproachfrom1997!wherewe  &p!( retainedthe1hourNAAQSforareasthathadnotmetitin '#* ordertomakeclearthatsuchareasretainedsubpart2 x)$, obligations!meritedreconsideration.Inaddition,we  indicatedthattheareabyareaapproachtorevocationof \ theNAAQSwasneedlesslyburdensomeandthatitmademore X sensetopromulgateoneruleestablishingthedateof   revocationofthe1hourNAAQSforallareas. `   ` Withrespecttothetimeatwhichthe1hourNAAQS  \  shouldnolongerapplytoareas,wesoughtcommentontwo   options.UnderOption1,wewouldrevokethe1hourNAAQS d  infull1yearaftertheeffectivedateofdesignationsfor `  the8hourNAAQS.ThekeyconsiderationforwhentheNAAQS   wouldberevokedwasthetimeatwhichareasdesignated h nonattainmentforthe8hourNAAQSwouldbesubjectto d conformityrequirementsforthe8hourozoneNAAQSandour  concernthatareasnotbesubjecttoconformityforboththe l 8hourandthe1hourNAAQSatthesametime.Webelieved h thatsinceourproposedantibackslidingprovisionswould  ensurethatprogresstowardcleanaircontinuedandwould p  obligateareastocontinuetomeetthecontrolobligations !l" associatedwiththeareas1hourclassification,therewas "$ noneedtoretaintheNAAQSandtheassociateddesignations t$& andclassifications.  &p!(  ` UnderOption2,weproposedtoretaintheNAAQSitself '#* (andtheassociateddesignationsandclassifications)for x)$, limitedpurposes# XcXX2Xc#2XcXX XcԀ(viz.,thoseidentifiedanddiscussedin $+t&. sectionVI.C.3.oftheproposedrule,whicharethesame  obligationsthatwouldcontinuetoapplyunderOption1)# XcXX2XcQ#2XcXX Xc.# XcXX2XcV#2XcXX Xc \ Forallremainingpurposes,wewouldrevokethe1hourNAAQS X andtheassociateddesignationsandclassifications1year   aftertheeffectivedateofdesignationsforthe8hour `  NAAQS.# XcXX2Xc#2XcXX XcԀThisapproachwouldnotcreateadifferent  \  substantiveresultthanOption1;underbothOptions,areas   wouldremainsubjecttothesameobligationsthatapplied d  basedontheir1hourclassification.Rather,Option2was `  basedonasomewhatdifferentlegalrationalethanOption1.    # XcXX2Xc#2XcXX Xcb.Summaryoffinalrule.WeareadoptingOption1.We h willrevokethe1-hourNAAQSinfull,includingthe d associateddesignationsandclassifications,1year  followingtheeffectivedateofthedesignationsforthe l 8-hourNAAQS.However,weareadoptingstronganti h backslidingprovisionswhichpreservecontrolobligations  mandatedbysubpart2foranareasclassificationforthe p  1hourNAAQS.Inlightoftheantibackslidingprovisions, !l" thedecidingfactorsupportingthescheduleforrevocation "$ istheconformityobligationforareas.Webelieveitis t$& unnecessarytorequireareastomeetconformityforboththe  &p!( 1-hourand8-hourNAAQSatthesametime;equallyimportant, '#* however,istheneedtoensurethatthereisnotimewhen x)$, conformitystopsapplyingforareasthataresubjecttoit $+t&. underthe1hourNAAQSanddesignatednonattainmentforthe  8hourNAAQS.Thus,weareadoptingaregulationthat \ providesforrevocationofthe1hourNAAQS1yearfollowing X theeffectivedateofthedesignationoftheareaforthe8   hourNAAQS# XcXX2Xc#2XcXX XcԀsincethatisthetimeanareadesignatedas `  nonattainmentforthe8hourNAAQSwillbesubjectto  \  conformityrequirementsforthe8hourNAAQS.    ` Ourfinalantibackslidingprovisionswillensurethat d  mandatorysubpart2controlmeasuresthatappliedduetoan `  areasclassificationunderthe1hourNAAQSwillcontinue   toapplyafterthe1hourNAAQSisrevokedinfull. h  ` Manycommentersbelieved,andweagree,thatOption1 d isaclearerapproachthanOption2.Sincebothoptions  wouldleadtothesamesubstantiveresult,weareadopting l theclearerapproach.Manycommentersrecommended h alternativesotherthanthoseproposedbyEPA.Ourbasis  forrejectingtheseapproachesisprovidedbelowandinthe p  RTCdocument. !l" c.0 ` Commentsandresponses"$` (#` (# COMMENT:Mostofthecommentswereceivedaddressedthe t$& issueofwhenweshouldrevokethe1hourNAAQS.Abouthalf  &p!( ofthecommentersfavoredrevocationofthe1hourNAAQSin '#* full1yearaftertheeffectivedateofthe8hour x)$, designations(proposedOption1).Onlyahandfulof $+t&. commentersfavoredpartialrevocationofthe1hourNAAQS  (proposedOption2).Almostathirdofthecommenterswho \ addressedthisissueopposedrevocationofthe1hourNAAQS. X ManyofthecommentersinthisgroupinsistedthatEPA   shouldretainthe1hourNAAQSbecauseitisnecessaryto `  protectpublichealthandsomenotedthatitmaybemore  \  protectiveofpublichealththanthe8hourNAAQSinseveral   areassuchastheSouthCoastandHouston# XcXX2Xc{#.Anumberof d  thesecommentersalsosuggestedthatrevocationwouldbe `  contrarytotheCAAandCongressionalintent.Several   commentersrecommendedalternativemeansortimingforthe h revocationofthe1hourNAAQS,includingarecommendation d torevokethe1hourNAAQSimmediatelyupondesignationsfor  the8hourNAAQS. l RESPONSETOMAJORCOMMENTS:Severalcommentersopposed h revocationatallbecausetheybelievethe1hourNAAQSis  necessarytoprotectpublichealth.Theissueofwhether p  the1hourNAAQSisnecessarytoprotectpublichealthisa !l" standardsettingissuethatwasresolvedin1997.Atthat "$ time,EPAdeterminedthatitwasnotnecessarytoretainthe t$& 1hourNAAQSasaNAAQSinordertoprotectpublichealth.  &p!( Insettingthe8-hourNAAQSin1997,weconcludedthat '#* replacingthecurrent1-hourNAAQSwithan8-hourNAAQSis x)$, appropriatetoprovideadequateandmoreuniformprotection $+t&. ofpublichealthfrombothshortterm(1to3hours)and  prolonged(6to8hours)exposurestoozoneintheambient \ air(62FR38863).Thesoleissuehereishowandwhenthe X transitionfromimplementationofthe1hourNAAQSto   implementationofthe8hourNAAQSshouldoccur. `   ` Webelievethestronganti-backslidingprovisionsin  \  section51.905willensurethatnotonlywillcontrols   alreadyadoptedunderthe1-hourNAAQScontinuetobe d  implementeduntilanareaattainsthe8-hourozoneNAAQS, `  butalsothattherewillbenoorminimaldelayinobtaining   additionalemissionsreductionscomparabletothosethat h wouldhavebeenrequiredhadthe1-hourNAAQSremainedin d place.Althoughattainmentofthe1-hourNAAQSwouldno  longerbeagoal,theprovisionsofsection51.905would l retaintheROPobligationsthatwouldhavebeenrequired h underthe1-hourNAAQS.Furthermore,theprovisionsof  section51.905alsowouldretainanareasobligationto p  eitherexpeditiouslycompletethe1-hourattainment !l" demonstrationorobtainemissionsreductionstowardmeeting "$ the8-hourNAAQSthatsubstituteforthosethatwouldhave t$& beenrequiredhadanareacompleteditsattainment  &p!( demonstrationonaschedulemoreexpeditiousthanthat '#* requiredsolelyforthe8-hourNAAQS.Thus,retainingthe x)$, 1-hourNAAQSitselfwouldbecomelargelysuperfluousfrom $+t&. thestandpointofobtainingtimelyemissionsreductions.   ` WedisagreewithcommentsthatrecommendedthatEPA \ revokethe1-hourNAAQSimmediatelyuponanonattainment X designationforthe8-hourNAAQS.Webelievethatsuch   timingwouldcreateagapwhenconformitywouldnotapply `  intheyearfollowingdesignationunderthe8-hourNAAQS  \  (sinceconformitydoesnotapplyforthe8hourNAAQSuntil   1-yearafterdesignation). d  COMMENT:f  g f  g Amajorconcernraisedbycommenterswasf  g Ԁthatf  g Ԁif `  theNAAQSwererevoked,f  g Ԁareaswouldnolongerhavetomeet   theSIPbudgetsestablishedforthe1hourNAAQSfor h conformitypurposes.Thesecommenterswereconcernedthat d 8hourozonenonattainmentareasthatwerenonattainmentor  maintenanceforthe1hourNAAQSwouldbeabletodetermine l conformityusinganotherlessprotectivetest,suchasthe h  build/nobuildtest.Onecommentersaidthatif  conformityisweakened,billionsofdollarswillbespenton p  transportationwithoutaccountabilityforpublichealth !l" impacts.Toavoidtheseresults,commenterssuggestedthat "$ conformityrequirementsforthe1hourNAAQScontinueto t$& applyuntilsomeotherpoint,suchaswhenbudgetsforthe  &p!( 8hourNAAQSareavailable,whenareashaveanapproved '#* maintenanceplanforthe8hourNAAQS,ortheendofareas x)$, 1hourmaintenanceplanningperiods(assumingtheseperiods $+t&. wouldremainastheyare,andwouldnotbeaffectedby  revocationofthe1hourNAAQS). \ RESPONSE:TheEPAproposedconformityregulationsforthe X new8hourozoneNAAQSandnewfineparticulatematterNAAQS   onNovember5,2003(68FR62690).Weproposedthatnew8 `  hourozonenonattainmentareasthathave1hourozoneSIPs  \  wouldmeetoneofseveraltests,andthemenuofoptionswe   offereddiffereddependingonhowthe8hourareaboundary d  relatestothe1hourareaboundary.Wewillconsiderthe `  issuesraisedbycommentersandprovideafullresponsein   thecontextofthatrulemaking. h  ` However,atthispointEPAcanrespondtothe d suggestionstorevokethe1hourNAAQSatalaterpointsuch  aswhen8hourbudgetsareavailable,ortheendofthe1 l hourmaintenanceplanningperiod.Underthesescenarios, h therewouldbeaperiodofyearswhereconformitywouldhave  tobedeterminedforbothNAAQSatthesametime:aresult p  thatEPAbelievescouldleadtoconfusionandadditional !l" burdenfortransportationandairqualityplanners.TheEPA "$ believesitissufficientthatconformitybedeterminedfor t$& oneozoneNAAQSatatime.f  g ԀSincethe8hourNAAQSisthe  &p!( healthbasedstandardanditismorestringentthanthe1 '#* hourNAAQS,webelieveconformingtothe8hourNAAQSwill x)$, besufficient. $+t&. COMMENT:  Onecommenterrecommendedthatweprovidean  optionthatallowsStatestosubmitan8hourconformity \ budgetearlyandsuspendthe1hourconformityrequirements X atthetimethe8hourbudgetisdeterminedtobeadequate.   Asecondcommentersuggestedsomethingsimilar,thatEPA `  requireStatestoexpeditebudgetsforthe8-hourstandard  \  inareaswherethe8-hourboundaryislarger.2XcXX XcԀ   RESPONSE:TheEPAdidnotproposetorevokethe1hour d  NAAQSearlierthan1yearafterdesignations,inpart `  becausewedidnotbelievethatareaswouldbeableto   submitan8hourSIPearlierthan1yearfollowing h designation.Furthermore,EPAsproposalwasintendedto d aligntherevocationofthe1hourNAAQSwiththe  applicationofconformityrequirementsforthe8hourNAAQS l 1yearaftertheeffectivedateof8hournonattainment h designations.# XcXX2Xc'#2XcXX XcԀTheEPAcontinuestobelieveitisunlikely  thatareaswillhaveadequatebudgetsthataddressthe8 p  hourNAAQSbeforeEPArevokesthe1hourNAAQS.Such !l" budgetsf  g cannotstandalonebutf  g havetobeassociatedwith "$ adoptedcontrolmeasuresanddemonstrationsofeither t$& attainmentorRFP,andwebelievedevelopingtheseSIPswill  &p!( takeStatessometime.OncetheSIPsaresubmitted,EPA '#* mustfindthemadequate,aprocesswhichEPAintendsto x)$, completewithin90daysofreceivingaSIP.Itisunlikely $+t&. thatStateswillf  g beabletocompletetheworktof  g submit8  hourozoneSIPs1yearfromtheeffectivedateof8hour \ ozoneareadesignations,andlesslikelythatStateswill X havesubmittedthemsufficientlyintimeforEPAtofind   themadequatebeforethe1hourNAAQSisrevoked. `   ` GiventhesefactsandthefactthatEPAdidnotpropose  \  anoptionforrevokingthestandardearlierthan1year   after8hourdesignationsareeffective,EPAf  g f  g doesf  g Ԁnotf  g f  g intend d  toprovidef  g Ԁforearlyrevocationofthe1hourNAAQS,nor `  willEPArequire8hourareastoexpeditedevelopmentof   their8hourSIPf  g Ԁforthispurposef  g .Allareasmustsubmit h SIPsassoonaspracticable,andEPAwantsStatestodevelop d qualitySIPsf  g Ԁtosupportattainmentdemonstrationsand  conformitydeterminationsf  g .Priortotherevocationofthe l 1hourNAAQS,newtransportationplanandtransportation h improvementplanmustconformtotheapplicableSIPbudgets  forthe1hourNAAQS.# XcXX2Xc*#2XcXX Xc p  COMMENT:SomecommentersrebuttedEPAsassertionthat !l" revokingthe1hourNAAQSisnecessarysothatagenciescan "$ focusonplanningforthe8hourNAAQS.Thesecommenters t$& statedthatneithertherevocationofthe1hourNAAQS(or  &p!( thebudgets)isjustifiedonthisbasiswithrespectto '#* transportationandemissionsmodeling,becauseundereither x)$, NAAQS,similarworkinestablishingbaseyearinventories, $+t&. andfutureforecastsoftravelandemissionsmustbedone.  Oncetheresourcesareinplacetomakefutureforecasts, \ commentersthoughtthatthelevelofeffortinbothtimeand X moneytoproduceanalysestodifferentregionalboundaries   isrelativelysmall,andampleresourcesareavailableto `  payfortheadditionalanalysesneededtodetermine  \  conformitytobothNAAQS.    ` TheEPAalsoreceivedcommentsoftheoppositeopinion. d  AnumberofcommenterssupportedEPA'sproposalthat `  conformityapplyforoneNAAQSatatime.Onecommenter   statedthatdeterminingconformityfortwoseparateozone h NAAQSwouldresultinundueadministrativeburden,create d confusionaboutrequirementsinthepublicprocessandmake  synchronizationoftheairqualityandtransportation l planningprocessesmoredifficult.Acoupleofcommenters h arguedthathavingtodetermineconformityforbothozone  NAAQSwoulddrainlimitedresourcesintransportationand p  environmentalagencies.Oneofthesecommenterscontended !l" thatdemonstratingconformityfortwoozoneNAAQScouldin "$ factdelayprogress,duetothehighadministrativeburdens. t$& RESPONSE:Whilethesecommentsfocussolelyonthe  &p!( resourcesnecessarytodetermineconformityforbothNAAQS, '#* EPAbelievesadiscussionofresourcesshouldincludeall x)$, aspectsofattainmentplanning.UnderEPAsproposal,with $+t&. revocationofthe1hourNAAQS,conformitywillnolonger  applyforthatNAAQSasamatteroflaw.Therefore,in \ orderforconformitytoapplyforbothNAAQSasone X commenterrequests,bothNAAQShavetobeimplementedatthe   sametime,i.e.,the1hourNAAQSwouldhavetobe `  implementedinadditiontothe8hourNAAQS.Thiswould  \  meancontinuationoftherequirementstodemonstrate   attainmentandmaintenanceofthe1houraswellasthe8 d  hourNAAQS.Theg f  g EPAbelievesthatitwouldbeasubstantial `  increaseinburdenforStatestoplanforattainmentofboth   NAAQS,whichincludesconformitybutalsoincludescreating h inventoriesforeachsourcesector,determiningfeasible d controlmeasures,writingrulestoimplementcontrol  measures,permittingstationarysources,establishingROP l plans,runningiterationsofairshedmodeling,and h demonstratingattainment.   ` In1997,EPAdeterminedthatthe1hourNAAQSisnot p  necessarytoprotectpublichealth.Wheretheyarenot !l" requiredbyantibackslidingprovisions,EPAdoesnot "$ believethattheadditionalburdenStateswouldundertakein t$& planningtoachieveboththe1hourandthe8hourNAAQSis  &p!( necessarytoprotectpublichealth. '#* # XcXX2Xc3#2.Whatrequirementsthatappliedinanareaforthe1 x)$, hourNAAQScontinuetoapplyafterrevocationofthe1hour $+t&. NAAQSforthatarea?(SectionVI.C.3.ofproposal;68FR  32820;section51.905(a)ofthedraftandfinalrules) \ a.Background.InthissectionoftheJune2,2003 X proposedrule(68FR32820),f  g f  g weconsideredwhatobligations   fromsubpart2thatappliedtoanareabasedonits `  classificationforthe1hourozoneNAAQSshouldcontinueto  \  applytosuchareaafterithasbeendesignatedforthe8   hourNAAQSandthe1hourNAAQShasbeenrevoked.We d  proposedthatthecontinuityofparticularobligationsmay `  varydependingontheattainmentstatusofanareaforthe   8hourNAAQS.Theproposedruleaddressedtwocategoriesof h areas:(1)areasthataredesignatednonattainmentforthe d 8hourNAAQSandthatweredesignatednonattainmentforthe  1hourNAAQSonorafterNovember15,1990;and(2)areas l thataredesignatedattainmentforthe8hourNAAQSandthat h weredesignatednonattainmentforthe1hourNAAQSonor  afterNovember15,1990.Furthermore,wedividedthetypes p  ofobligationsintofourcategoriesforpurposeofour !l" analysis:1)mandatorycontrolmeasures(e.g.,f  g f  g g NOxf  g RACT, "$ I/M,andfuelprograms);2)discretionarycontrolmeasures t$& (e.g.,controlmeasuresorotherobligationstheState  &p!( selectedandadoptedintotheSIPforpurposesof '#* attainment,ROPoranyothergoaltobenefitairquality, x)$, butwhicharenotspecificallymandatedbysubpart2);3) $+t&. growthmanagement(NSRf  g );and4)planningactivities  (attainmentandmaintenancedemonstrationsandRFPplans). \ Weaddressedconformityseparatelybecauseitisasubpart1 X requirement.Inaddition,wef  g Ԁaddresf  g sedtheg f  g f  g NOxf  g ԀSIPCall   separatelysincethisobligationappliesf  g Ԁstatewideandf  g  `  withoutrespecttothedesignationstatusofareaswithin  \  theState.    ` InthedraftregulatorytextreleasedinAugust2003, d  forareasdesignatednonattainmentforthe8hourNAAQS,we `  brokeintotwogroupstheareasdesignatednonattainmentfor   the1hourNAAQSonorafterNovember15,1990:(1)areas h thatremaindesignatednonattainmentforthe1hourNAAQSat d thetimeofrevocationofthe1hourNAAQS;and(2)areas  thatweredesignatednonattainmentforthe1hourNAAQSbut l thathavebeenredesignatedtoattainmentforthe1hour h NAAQS(i.e., maintenanceareas)atthetimeofrevocation  ofthe1hourNAAQS. C  29      ׀Inresponsetocommentsonthe p  proposedruleanddraftregulatorytext,thefinal !l" regulationcreatesthesamesubcategorizationforareas "$ designatedattainmentforthe8hourNAAQS.Inthefinal t$& ruleandinthepreamblediscussionbelow,wealsobreak  intothesametwogroupstheareasdesignatedattainmentfor \ the8hourNAAQS.Thus,inthepreambleandrulewe X considertheobligationsthatcontinuetoapplyforfour   categoriesofareas:(1)areasthatremaindesignated `  nonattainmentforthe1hourNAAQSatthetimeof  \  designationasnonattainmentforthe8hourNAAQS;(2)areas   thataremaintenanceareasforthe1hourNAAQSatthetime d  ofdesignationasnonattainmentforthe8hourNAAQS;(3) `  areasthatremaindesignatednonattainmentforthe1hour   NAAQSatthetimeofdesignationasattainmentforthe8 h hourNAAQS;and(4)areasthataremaintenanceareasforthe d 1hourNAAQSatthetimeofdesignationasattainmentfor  the8hourNAAQS.Boththepreambleandtherulemayuse l thefollowingtermstodiscussthesefourcategories:(1)8 h hourNAAQSnonattainment/1hourNAAQSnonattainment(2)8  hourNAAQSnonattainment/1hourNAAQSmaintenance;(3)8 p  hourNAAQSattainment/1hourNAAQSnonattainment(4)8hour !l" NAAQSattainment/1hourNAAQSmaintenance.Undereachof "$ thesesectionsinthepreamble,weaddresshowthefinal t$& ruletreatsthefourtypesofobligationsidentifiedinthe  &p!( proposedrule:(1)mandatorycontrolmeasures;(2) '#* discretionarycontrolmeasures;(3)growth;and(4)planning x)$, obligations. $+t&. b.Summaryoffinalrule.Theapproachweareadoptingin  thefinalruleissummarizedbelowundertheindividual \ sectionsdiscussingeachcategoryofareaandtypeof X controlobligation.   c.Section51.905(a)(1):8hourNAAQSnonattainment/1Hour `  NAAQSnonattainment  \   ` (i)Mandatorycontrolmeasures.(SectionVI.C.3.a.i.   ofproposedrule;see68FR32820;sections51.900(f)and d  51.905(a)(1)ofthedraftandfinalrules.) `   ` (A)Background.Forareasdesignatednonattainment   forthe1hourNAAQSatthetimetheyaredesignated h nonattainmentforthe8hourNAAQS,weproposedthat,tothe d extenttheareahasmetamandatorySIPobligationunderthe  CAAthatisincludedaspartoftheapprovedSIP,theState l maynotmodifyorremovethatmeasureexcepttotheextent h thatitmayhavemodifiedorremovedthatmeasurefor  purposesofthe1-hourNAAQS(68FR32820).Forexample,if p  anareawasclassifiedasseriousforthe1hourozoneNAAQS !l" andrequiredtohaveanenhancedI/Mprogramaspartofits "$ SIP,theStatecannotremovetheenhancedI/Mprogramfor t$& thatareaeventhoughitmaybeclassifiedasmarginalor  &p!( moderateforthe8hourozoneNAAQS.However,underthe '#* proposal,theStatemaymodifytheenhancedI/Mprogram x)$, consistentwithEPAsenhancedI/Mregulations,justasit $+t&. mayhavedoneforpurposesofthe1hourNAAQS.(Weaddress  belowwhentheobligationtoretainsuchcontrolmeasuresas \ activecontrolprogramsnolongerapplies,thegeographic X areainwhichtheobligationapplies,andthedemonstration   aStatemustmakeatthatpointtomodifytheSIP.) `   ` ForcontrolmeasuresthattheStatehasnotyet  \  adopted,weproposedthattheStateremainsobligatedto   adoptandsubmitsuchcontrolmeasures.And,onceadopted d  intotheapprovedSIP,theStatemaynotmodifyorremove `  suchmeasuresexcepttothesameextentthatitcouldhave   modifiedorremovedthemforpurposesofthe1-hourNAAQS. h  ` Ourdraftregulatorytextreferredtotheseobligations d as applicablerequirementsandweidentifiedthesubpart2  mandatorycontrolmeasuresinthedefinitionssectionunder l  applicablerequirements. h  ` (B)Summaryoffinalrule. Weareadoptingthe  approachweproposed.(Seesections51.905(a)(1)(i)and p  51.900(f)ofthefinalrule.)Allareasdesignated !l" nonattainmentforthe8-hourozoneNAAQSanddesignated "$ nonattainmentforthe1hourozoneNAAQSatthetimeof t$& designationforthe8hourNAAQSremainsubjecttocontrol  &p!( measuresthatappliedbyvirtueofthearea'sclassification '#* forthe1-hourNAAQS. x)$,  ` Aswestatedinthepreambletotheproposedrule(68 $+t&. FR32819),thereareanumberofprovisionsintheCAAthat  webelieveareevidenceofCongressintentthatthese \ obligationscontinuetoapplydespiteEPAsdetermination X thatthe1hourNAAQSisnolongernecessarytoprotect   publichealth.Forexample,atthetimeofthe1990 `  AmendmentstotheCAA,Congressdesignatedandclassified  \  existingozonenonattainmentareas(andclassifiedallother   ozonenonattainmentareas)asamatteroflaw.Congress d  alsoprovidedthatareascouldnotremovefromtheSIP `  controlsmandatedbysubpart2evenaftertheareaattains   theNAAQSandisredesignatedtoattainment.Atmost,the h Statecouldmovesuchcontrolstothecontingencyplan d provisionsoftheSIP.SeeCAAsection175A(d).Also  significantisthatin1990,Congressenactedaprovision l specifyingStatesobligationswithrespecttocontrol h measuresforaNAAQSafterEPArevisedthatNAAQStobeless  stringent.Insection172(e),Congressspecifiedthatif p  EPArevisesaNAAQSandmakesitlessstringent,EPAmust !l" promulgateregulationsapplicabletoareasthathavenotyet "$ attainedtheoriginalNAAQStorequirecontrolsthatareno t$& lessstringentthanthecontrolsthatappliedtoareas  &p!( designatednonattainmentpriortosuchrelaxation.We '#* believethat,ifCongressintendedareastoremainsubject x)$, tothesamelevelofcontrolwhereaNAAQSwasrelaxed,they $+t&. alsointendedthatsuchcontrolsnotbeweakenedwherethe  NAAQSismademorestringent.Finally,wenotedthatthe \ SupremeCourtcautionedagainstmakingsubpart2 abruptly X obsolete.Forareasdesignatednonattainmentin1990,   Congressintendedthemandatoryrequirementsofsubpart2to `  apply(asimplementedcontrolsorcontingencymeasures)for  \  asignificantperiodoftime.Webelieveifweallowed   areastoremovethosemandatedcontrolsfromtheirSIPsit d  wouldrenderthoseprovisionsprematurelyobsolete,contrary `  toCongressionalintent.Weadoptinfulltheanalysis   providedat68FR32819,1stand2ndcolumns. h  ` Thefinalrulealsoreflects,withseveralexceptions, d thetableinappendixBoftheJuneproposalwhich  identifiedtheapplicablerequirements.Thedefinitionof l  applicablerequirementsinsection51.900(f)ofthedraft h regulatorytexterroneouslyexcludedsomeofthe  requirementsincludedinappendixB.Therequirementsthat p  werentincludedintheproposedregulatorytextdefinition !l" ofapplicablerequirementbutareincludedinthedefinition "$ inthefinalruleare: t$&  A8L9;<=>?@(x8"8"  8v23  0 `   Enhanced(ambient)monitoringundersection182(c)(1)  &p!( oftheCAA.8vw݌'#*` (#` (# Ќ  "8"  8w23  0 `   Transportationcontrolsundersection182(c)(5)ofthe x)$, CAA.8wx݌$+t&.` (#` (# Ќ  _"8"  8x23  0 `   Vehiclemilestraveledprovisionsofsection182(d)(1)  oftheCAA.8x&y݌\` (#` (# Ќ  "8"  8z23  0 `   _NOx_Ԁrequirementsundersection182(f)oftheCAA.8z2z݌X` (#` (# Ќ   ` Oneexceptioninwhichthefinalruledoesnotreflect   appendixBoftheproposalconcernstherequirementfor `  reformulatedgasoline(_RFG_).AppendixBerroneously  \  included_RFG_Ԁasanapplicablerequirementundersubpart2.   Asdiscussedbelowunder Commentsandresponses,itisnot d  anapplicablerequirementundersubpart2andisnot `  includedassuchinsection51.900(f)ofthefinalrule.In   addition,AppendixBlisted_NSR_Ԁ(majorsourceapplicability h and_offets_)as applicablerequirementsundersubpart2. d Althoughthesewouldbeapplicablerequirementsunder  subpart2forthe8hourstandard,theywouldnotbe l applicablerequirementsundersubpart2forthe1hour h standardafterthe1hourstandardisrevoked.c C  30         (8xA8L9;<=>?@Wv ` (C)Commentsandresponses p  COMMENT:ConcerningtheJune2,2003proposal,several !l" _commenters_Ԁbelievedthatnotallcontrolrequirements "$ requiredbyanareas1hourclassificationwould t$& necessarilyhelpachievethe8hour_NAAQS_Ԁandtherefore  opposedtheproposedantibackslidingprovisions.Other \ _commenters_Ԁsupportedtheproposal. X  ` Concerningthedraftregulatorytext,_commenters_   generallyreiteratedtheircommentsfromtheJune2,2003 `  noticeincommentingonthedraftregulatorytext.  \  RESPONSE:Aswenotedaboveandinthepreambletothe   proposedrule,weexaminedtheCAAasawholetodiscern d  CongressionalintentsinceCongressdidnotspecifically `  addressantibackslidingwhereEPApromulgatedamore   stringent_NAAQS_.Afterconsideringthe asamatteroflaw h designationandclassificationforthe1hour_NAAQS_,section d 172(e),andtheCAAs_redesignation_Ԁprovisions,webelieve  thatCongressintendedtheseareastocontinuetoimplement l requirementsthatappliedintheareaforthe1hour_NAAQS_. h COMMENTS:TheEPAsJune2proposallisted_RFG_Ԁinappendix  Basan applicablerequirementforsevereandaboveozone p  _nonattainment_Ԁareas;itwasalsolistedasan applicable !l" requirementinthedraftregulatorytextundersection "$ 51.900(f).TheEPAreceivedanumberofcommentsaddressing t$& _RFG_Ԁrequirements.Some_commenters_Ԁarguedthattheprogram  &p!( wasofnoenvironmentalbenefitincertainlocations,and '#* shouldnotberequired. One_commenter_Ԁsuggestedthatwhere x)$, itisestimatedthatthecostspertonofVOCremovalwould $+t&. _bearound$36millionperdailytonremovedoraround  $100,000perannualtonremoved,withnomeasurablebenefit \ toozonelevels,thatrequiringuseofRFGwouldbean X  absurdresultjustifyingawaiveroftheRFGrequirement.   Onecommenterarguedthattherulesprovidingforozone `  nonattainmentareastooptintotheRFGprogramshouldbe  \  liberalized,toallowadditionalareastoavailthemselves   ofthebenefitsofRFG.Othercommentersarguedagainst d  suchliberalization,onthebasisthatthefuelsindustryis `  alreadyburdenedwithimplementationoffarreachingfuels   regulationsanddoesnotneedtheadditionaldifficulties h thatwouldbeassociatedwiththeproliferationofRFGopt d ins.  RESPONSE:TheEPAhasdecidedthatitisnotappropriateto l listRFGasan applicablerequirementinthefinalrulein h section51.900(f).TheRFGprogramisnotadoptedasa  StateprograminSIPs,asaretheother applicable p  requirementslistedintodaysfinalrule.Rather,RFGis !l" requiredunderaFederalprogram.Itisprescribedinsome "$ instancesbystatute,andinotherinstancesStatesare t$& allowedtooptinandoptoutoftheprograminaccordance  &p!( withFederalstatutoryprescriptionsandEPArules.TheEPA '#* recognizesthatthescopeandapplicabilityoftheRFG x)$, programduringandafterimplementationofthenew8hour $+t&. ozonestandardraisesvariousissuesthatneedfurther  clarification.However,suchclarificationismore \ appropriatelyprovidedinaseparateundertaking.Since X FederalRFGdoesnotappearonthefinalruleslistof    applicablerequirementsinsubpart2,thereisnoneedto `  respondinthisrulemakingtothecommentsregarding  \  implementationoftheRFGprogram.Therefore,whilenotan    applicablerequirementundertodaysrules,theRFG d  requirementisnonethelessapplicableundertheCAAfor `  certainareas,andEPAwilldetermineinthefuturewhether   thisrequirementwouldchangefortheseareaswhenthey h attaintheozoneNAAQS. d COMMENT:Onecommenternotedthatthelanguageinthedraft  regulatorytextisbaseduponthedateofrevocationofthe l 1hourozoneNAAQS,whichisatleastoneyearlaterthan h thatspecifiedintheproposedrule.Thedateofrevocation  isalsohighlyuncertaincomparedtothedateof p  designation,whichisdrivenbytheConsentDecree.The !l" DraftRegulatoryTextthereforeconflictswiththeproposed "$ rulelanguage.Thecommenterprefersuseofthedateof t$& designationfortheseandotherapplicablerequirements.  &p!( RESPONSE:Theregulatorytexthasbeenrevisedtokeythe '#* requirementfromtheeffectivedateofdesignationforthe x)$, 8hourNAAQS. $+t&. COMMENT:Onecommenterbelievedtherewasaconflict  betweentheJune2,2003noticeandthedraftregulatory \ textconcerningthetimingofthe1-hourNSRobligation.The X draftsection51.905(a)(1)provisionwouldapplyforareas   designatednonattainmentforthe1hourNAAQSatthetimeof `  revocationofthe1hourNAAQS,buttheJune2,2003notice  \  provisionwouldapplytoareasdesignatednonattainmentfor   the1hourNAAQSatthetimeofdesignationofthe8hour d  NAAQS.Thecommenterrecommendedthattherulebebasedon `  thedateofdesignationforthe8hourNAAQS. x    RESPONSE:Weagreetherewasaconflictinthedraft h regulatorytextonthismatter.However,asdiscussed d below,thefinaldiffersfromtheproposalinthatafterthe  1hourNAAQSisrevoked,NSRunderthe1hourNAAQSwillno l longerbearequiredimplementationplanelementinareas h thatare8HourNAAQSnonattainment/1HourNAAQS  nonattainment.2XcXX XcԀInstead,NSRunderthe8hourNAAQSwill p  apply.# XcXX2Xc# !l"  ` (ii)Discretionarycontrolmeasures. Thisdiscussion "$ ofdiscretionarymeasuresincludeshowweplantotreat t$& enforceablecommitmentsapprovedintotheSIP.(section  &p!( VI.C.3.a.ii.ofproposedrule,see68FR32821,andsection '#* VI.C.3.a.v.ofproposedrule;see68FR32822;Section x)$, 51.905(d)ofdraftandfinalrules;thereisnoparallel $+t&. provisioninthefinalrule.)   ` (A)Background.ManyapprovedSIPscontaincontrol \ measuresthatarenotspecifiedundersubpart2forthe X area,butthattheStatechosetoadoptaspartofthe   demonstrationofattainmentorpartoftheROPrequirement `  forthe1-hourNAAQS.Forthesekindsofmeasures,we  \  proposedthatStatesretainthediscretiontheynowhaveto   modifytheserequirementsintheirSIPs.Forpurposesof d  the1-hourNAAQS,Statesmaycurrentlyreviseorremove `  thoserequirementssolongastheymakeademonstration   consistentwithsection110(l)thatsuchremovalor h modificationwouldnotinterferewithattainmentofor d progresstowardthe1-hourozoneNAAQS(oranyother  applicablerequirementoftheCAA).  C  31      ׀Oncethe1hour l standardisrevoked,forpurposesofthe8-hourNAAQS,the h samediscretiontomodifyaSIPwouldapplyexcepttheState  wouldneedtomakethedemonstrationrequiredbysection p  110(l)withrespecttothe8-hourNAAQS,notthe1-hour !l" NAAQS.See68FR32821foranexampleofhowthiswould "$ work.   ` WealsoproposedthatStatesremainobligatedtomeet \ enforceablecommitmentsapprovedintoaSIPtothesame X extentasiftheywereadoptedmeasures(68FR32822).This   includesenforceablecommitmentstoperformamidcourse `  review.TheonlywayaStatemaymodifyorremovesucha  \  commitmentisthroughaSIPrevisionmakingtherequired   demonstrationundersection110(l). d   ` (B)Summaryoffinalrule.Weareadoptingthe `  approachwesetforthinourproposedrule.AStatemay   reviseorremovediscretionarycontrolmeasures(including h enforceablecommitments)containedinitsSIPforthe1hour d NAAQSsolongastheStatedemonstratesconsistentwith  section110(l)thatsuchremovalormodificationwillnot l interferewithattainmentoforprogresstowardthe8-hour h ozoneNAAQS(oranyotherapplicablerequirementofthe  CAA).Undertherule,Statesremainobligatedtomeetany p  SIPapprovedcommitmenttoperformamidcoursereview. !l" TheseSIPcommitmentsgenerallydonotbindtheStatesto "$ takeanyspecificactioninresponsetotheresultsofthe t$& midcoursereview.TheEPAanticipatesthatratherthan  &p!( usingthesereviewstoensureareasmeetthe1hourNAAQS '#* (whichwillhavebeenrevoked),StatesandEPAcanusethese x)$, reviewstoensureprogressisbeingmadeconsistentwith $+t&. needsforthe8hourNAAQS.   ` Note,however,thatsincegeneralprovisionsfor \ modifyingorremovingcontrolmeasuresinaSIParealready X providedinthestatute(sections110(l)and193),wedonot   believethereisaneedtohaveaduplicativeprovisionin `  thisfinalrule.Therefore,eventhoughthedraft  \  regulatorytextcontainedsuchaprovision(section   51.905(d)),thefinalruledoesnotcontainthatprovision. d   ` (C)Commentsandresponses `  COMMENT:Severalcommenterssupportedtheproposal   regardingdiscretionarycontrolmeasures.Othercommenters h believedthatStatesshouldnotbeheldtocommitmentsto d submitthemidcoursereviewrequiredundertheir1hour  SIP.Somecommentersobjectedtotheprovisionindraft l regulatorytextforallowing relaxationsoftheSIPunder h sections110(l)and193oftheCAA.  RESPONSE:Sections110(l)and193allowStatestomodify p  thediscretionarycontrolsintheirSIPsiftheprovisions !l" ofthosesectionsaremet.Whilewebelieveitisimportant "$ topreventbackslidingconsistentwiththestatutory t$& provisions,wedonotbelieveitisappropriatetofurther  &p!( restrainthediscretionCongressgrantedtoStatesin '#* determiningtheappropriatemixofcontrolsintheSIP.We x)$, believethataStatemayrevisediscretionarycontrols $+t&. approvedinitsSIPaslongasitmeetsthecriteria  specifiedinsections110(l)and193.Webelievethetests \ providedinsections110(l)and193willpreventtheadverse X effectsenvisionedbythecommenter.    ` (iii)Measurestoaddressgrowth.(section `  VI.C.3.a.iiiofproposedrule;see68FR32821;sections  \  51.900(f)and51.905(a)(1)ofthedraftandfinalrule.)    ` (A)Background.Ingeneral,theSIPprovisionsinthe d  CAAincludeoneprovisiontoaddressgrowth!nonattainment `  NSR.Wediscussconformityforallareasinalater   section. h  ` Forareasthatare8hourNAAQSnonattainment/1hour d NAAQSnonattainment,weproposedintheJune2,2003notice  thatthemajorsourceapplicabilitycut-offsandoffset l ratiosfornonattainmentNSRthatappliedforanareas1 h hourclassificationcontinuetoapply.   ` (B)Summaryoffinalrule.Thefinalruletreats1 p  hourNSRasarequirementthatwillnolongerapplyoncethe !l" 1hourNAAQSisrevoked.Weprovideamorethorough "$ discussionoftheapproachinourfinalruleandthe t$& rationaleinthesectionbelowdiscussing1hourNAAQS  &p!( obligationsthatnolongerapplyasofrevocationofthe1 '#* hourNAAQS. x)$,  ` (C)Commentsandresponses.Commentsandresponses $+t&. areincludedinthesectionbelowdiscussing1hourNAAQS  obligationsthatnolongerapplyasofrevocationofthe1 \ hourNAAQS. X 2XcXX Xcg  ` (iv)f  g f  g PlanningSIPsf  g f  g .f  g    f  g  ` (A)f  g f  g OutstandingROPobligation.(sectionVI.C.3.a.iv `  ofproposal;68FR32822;Section51.905(a)(1)ofthedraft  \  andfinalrules)   f  g  ` f  g (1)f  g Background.IntheJune2,2003proposal,we d  proposedthatStatesremainobligatedtoaddressseparately `  1hourROPrequirementsthatdonotoverlapwithRFP   obligationsforthe8-hourNAAQS." C  32      ׀WhereoutstandingROP h andRFPobligationsoverlap,theareaneednotsubmita d separateROPplanforthe1-hourNAAQSbutmustshowthat  the8hourROPplanisnolessstringentthanthe1hourROP l requirement.ForROPprovisionsalreadyadoptedintothe h SIP,weproposedthattheStatemayremoveorrevisecontrol  measuresneededtomeettheROPmilestoneifsuchcontrol p  measureswerediscretionary(i.e.,notmandatedbysubpart2 !l" fortheareas1hourclassification),asdiscussedabove, "$ andtheStatemakesademonstrationundersection110(l) t$& includingademonstrationthattherevisionwillnot  &p!( interferewithmeetingthe1hourROPand8hourRFPgoals.   ` f  g (2)f  g Summaryoffinalrule.Weareadoptingthe \ approachsetforthinourproposedruleforareasthatare X 8hourNAAQSnonattainment/1hourNAAQSnonattainment.   StatesremainobligatedtomeettheCAA-mandatedROP `  emissionreductiontargetsthatappliedforthe1-hour  \  NAAQS,butdiscretionarymeasuresadoptedtomeetthose   targetsmaybemodified,iftheStatemakesthenecessary d  showingundersection110(l). `   ` Inaddition,weareprovidingfurtherclarification   regardinghowthisobligationapplies.Areasthathavean h outstandingobligationforanapproved1hourROPSIPfor d oneormoreoftheROPperiods(e.g.,19992002,20022005,  20052007)muststilldevelopandsubmittoEPA(ifthey l havenotalreadydoneso)alloutstanding1hourROPplans. h Wherea1hourROPobligationoverlapswithan8hourRFP  requirement,theStates8hourRFPmeasurescanbeusedto p  satisfythe1hourROPobligation. !l"  ` TheStatemaychoosetoshowthatboththe8hourand "$ 1hourROPobligationsaremetthroughasingle8hourplan t$& submittal.Topreventbacksliding,theStatemustensure  &p!( thatthe8hourRFPemissionplanisatleastasstringent '#* asthe1-hourROPemissiontarget,fortheyearinwhich1 x)$, hourROPmustbemet# XcXX2Xc/#2XcXX Xc.TheStatemaydothisbyfirst $+t&. establishinganRFPemissiontargetfortheentire8-hour  ozonenonattainmentarea,forthe1hourROPtargetyear. \ Ifthe8hourRFPemissiontargetforthe8hourareafor X thesameperiodismorestringentthanthe1hourROP   emissiontargetforthe1hourarea(assumingthe8hour `  areaincludestheentire1hourarea),theStateisnot  \  obligatedtosubmitaseparate1hourROPplan,butcanrely   solelyonthe8hourRFPplanandemissiontargetto d  demonstratethatthe1hourtargetwillbemet.However, `  theStatemustensurethattheemissiontargetwillbemet   forthesameperiodasfor1hourROP(e.g.,20032005). h TheStatemayrelyonanycontrolmeasuretomeetbothROP d forthe1hourNAAQSandRFPforthe8hourNAAQS.Appendix  Abelowprovidesanexampleofhowthismightwork.# XcXX2Xc>#XXX Xc l # XcXXX#2XcXX Xc ` # XcXX2Xc3#IntheJune2,2003proposal(68FR32835),weproposed h thattheAgencysCleanDataPolicyp C  33      ׀wouldremaineffective  underthe8hourozoneNAAQS,andwethereforeintendto p  applythispolicyinimplementingthisfinalruleforareas !l" thatachievethe8-hourNAAQS.2XcXX XcԀThus,ifanareaattainsthe "$ 8hourozoneNAAQS,undertheAgencys CleanDataPolicy, t$& EPAmaywaivethe1hourRFPobligationfortheareabased  &p!( onadeterminationthattheareahasattainedthe8hour '#* NAAQS.Underthatpolicy,theStatewillnotbesubjectto x)$, the1hourRFPrequirementforsolongasthearearemains  inattainmentwiththe8hourNAAQS.# XcXX2Xc.#(TheEPAwilladdress \ theapplicabilityoftheCleanDataPolicyfor8hourozone X nonattainmentareasinPhase2oftheimplementationrule.)     ` Webelievethatthereisambiguityinthestatute `  regardingwhetherareasshouldremainsubjecttothe  \  requirementtosubmitplanningSIPs,suchasthe1hourROP   plans.Unlikecontrolobligations,wedonotbelievethere d  isasstronganargumentthatCongressintendedareasto `  continuetosubmitplanningSIPsforaNAAQSthatEPAhas   determinedisnolongernecessarytoprotectpublichealth. h Section172(e),whichapplieswhenEPArelaxesaNAAQS,only d requiresEPAtoensurethatcontrolmeasuresarenoless  stringentthantheywereforthemorestringentNAAQSthat l hasbeenreplaced.ItdoesnotindicateaCongressional h intentthatareasremainobligatedtoplanforandmeeta  NAAQSasitexistedbeforeitwasrevised.However,both p  attainmentdemonstrationsandROPplansresultinthe !l" adoptionofcontrolobligations.And,ifEPAdetermined "$ thattheseplanningrequirementsdidnotapplyatall,areas t$& currentlydesignatednonattainmentforthe1hourNAAQSthat  &p!( havenotmettheseobligationsmightbesubjecttoless '#* stringentcontrolsthanwouldhaveotherwiseapplied.Thus, x)$, inconsideringhowtotreatthisobligation,webalancedthe $+t&. needtoensurethesamelevelofcontrolwiththe  difficultiesassociatedwithmeetingthisobligation. \  ` ForpurposesofROP,theexerciseofcalculatingthe X reductionsnecessarytomeetROPisrelativelysimple.   Moreover,asprovidedabove,eveniftheStatemust `  calculateROPseparatelyforthe1hourand8hourNAAQS,it  \  maystillrelyononeormoreofthesamecontrolmeasures   tomeetboththoseobligations.Additionally,webelieve d  thatmostoftheareaswithanoutstanding1hourROP `  obligationwillbeabletodemonstratethatthe8hourRFP   targetsforthesametimeperiodwillbemorestringentand h thuswillnotberequiredtoprepareaseparate1hourROP d plan.Finally,wenotethatStateshavealreadysubmitted  and,EPAhasalreadyapproved1hourROPplansformost1 l hournonattainmentareas.Thus,theantibacksliding h provisionsregardingthecontinuedobligationtoadoptand  submit1hourROPplanswillaffectonlyahandfulofareas. p  Forthesereasons,weareadoptingaregulationthat !l" requiresareasthatare8hourNAAQSnonattainment/1hour "$ NAAQSnonattainmenttocontinuetoadoptandachievethe t$& levelofROPreductionsmandatedbyCongressundertheCAA  &p!( forthatNAAQS. '#*  ` (3)Commentsandresponses x)$, COMMENTSONJUNE2,2003PROPOSAL:Fewcommenterssubmitted $+t&. commentsontheportionoftheproposedrulediscussingthe  antibackslidingrequirementsapplicableto1hourROP. \ Severalcommentersgenerallyopposedanycontinuedplanning X obligationsunderthe1hourNAAQS,butdidnotraise   specificconcernswithrespecttoROP.Similarly,anumber `  ofothercommentersopposedrevocationofthe1hourNAAQS  \  andurgedretentionofall1hourplanningandcontrol   obligations;butagain,thesecommentersdidnotraise d  concernsspecifictotheproposedantibackslidingapproach `  forROP.    ` Onecommenter,addressingsection51.905(a)(1)(iii)of h thedraftregulatorytext,arguedthatStatesshouldhave d theabilitytomodifyROPmeasuresifitcanbedemonstrated  thattheyarenotneededforpurposesofmeeting l requirementsunderthe8hourNAAQSorifmeasuresareno h longerappropriateduetoupdatedtechnicalinformation  regardingemissionsinventoryandcontrolstrategy p  effectiveness.Anothercommenterobjectedtoretainingthe !l" 1hourROPrequirement,primarilybecauseareasrecently "$ reclassifiedtoahigherclassificationwouldhavea t$& continuingobligationforROPeveniftheywerenotrequired  &p!( todevelopanRFPplanunderthe8hourNAAQS.Another '#* commenterbelievedthe1hourROPrequirementshouldonlybe x)$, requiredwhereitisdemonstratedtobeneededfor $+t&. attainmentofthe8hourNAAQS.  RESPONSE:Asprovidedabove,webelieveCongressintended \ areastocontinuetohavecontrolmeasuresnolessstringent X thanthosethatappliedforthe1hourNAAQS.Becausethe   ROPobligationresultsincontrolobligations,webelieve `  areasshouldremainobligatedtoadoptoutstandingROP  \  obligationstoensurethattheROPmilestonesaremet.Ifa   Statebelievesadoptedcontrolsarenotthebestfitforthe d  8hourNAAQS,theStateretainsfulldiscretiontorevise `  thosecontrolssolongastherevisiondoesntinterfere   withtheROPmilestones. h  ` Withoutthisprovision,anareawithanunmet d obligationtosubmitandimplementaROPplanunderthe  1-hourNAAQScouldexperiencebackslidingbybeingreleased l fromtheobligationtohavecontrolsinplacethatachievea h specifiedlevelofemissionsreductionsduringtheinterim  periodpriortoimplementationoftheSIPrequiredforthe p  8-hourNAAQS.Inotherwords,ifthe1-hourNAAQSwerenot !l" revoked,theareawouldhavebeenrequiredtocontinueto "$ ensureemissionswouldbereducedbyspecifiedlevelsin t$& specifictimeframes.Ifthefinalrulecontainedno  &p!( provisioncomparabletosection51.905(a)(1)(i),achievement '#* ofthoseemissionsreductionswouldalmostcertainlybe x)$, delayed.Becausewearetransitioningtoamorestringent $+t&. andprotectiveairqualityNAAQS.Weseenoreasonwhy  thereshouldbeprovisionsthatwouldprovideless \ protectiontopublichealth. X  ` (B)Unmetattainmentdemonstrationobligations   (sectionVI.C.3.a.ivofproposal;see68FR32822;section `  51.905(a)(1)(ii)ofthedraftandfinalrules)  \   ` (1)Background.Mostareasdesignatednonattainment   forthe1hourozoneNAAQShavefullyapprovedattainment d  demonstrationsforthe1hourNAAQS.Becausethereareso `  fewareaswithoutapprovedattainmentdemonstrations,inthe   proposedruleweidentifiedthetwotypesofsituationsof h whichwewereawareandsolicitedcommentonhowtohandle d thosesituations.First,thereareafewareasthatdonot  haveafullyapprovedattainmentdemonstrationbecausethe l areahasnotactedinaccordancewiththetimelinesprovided h undertheCAA.Thesecondsituationisanareawhichhasa  futureobligationtosubmitanattainmentdemonstration.In p  general,theseareareasthat,overthepastseveralyears, !l" havebeenreclassified(i.e., bumpedup)toahigher "$ classification.Inthepreambletotheproposal,we t$& discussedthepolicyreasonsthatwouldsupportretentionof  &p!( theobligationtosubmitanattainmentdemonstrationandthe '#* policyreasonsthatwouldcounselagainstretentionofthat x)$, obligation(68FR32822).Forboththesegroupsofareas, $+t&. wesolicitedcommentonwhethertoretaintheobligationto  developa1-hourattainmentdemonstration.Inaddition,we \ solicitedcommentontwoalternativesthatwouldaddress X manyofthepolicyconcernswenoted.    ` Alternative1wouldrequirethatareaswithacurrent `  orpastdueobligationtosubmitaneworrevisedattainment  \  demonstrationinsteadberequiredtosubmitaSIPrevision   thatwouldobtainanadvanceincrementoflocalemissions d  reductionstowardattainmentofthe8-hourozoneNAAQS `  withinaspecified,short-termtimeframe;5percentand10   percentweresuggestedpossibilitiesfortheincrement. h UnderAlternative2,areaswithacurrentorpastdue d obligationtosubmita1-hourattainmentdemonstrationwould  berequiredtosubmittheir8-hourozoneattainment l demonstrationearlyinlieuofbeingrequiredtosubmita h 1-hourattainmentdemonstration.Thedraftregulatorytext  wasdevelopedusingthefirstalternative,anduseda10 p  percentincrement. !l"  ` (2)Summaryoffinalrule.Inthefinalrule,weare "$ allowingtheStatestochooseamongthreeoptionsthatare t$& tailoredaftertheapproachesaddressedintheproposed  &p!( rule.Thus,ratherthanestablishingonemandatory '#* approach,weareadoptingarulethatwillallowStatesto x)$, chooseanyoneofthefollowingthreeoptions: $+t&.  A8L9;<=>?@(x8"8"  8œ23  0 `   Option1.Submita1hourattainmentdemonstration.8œ݌` (#` (# Ќ  "8"  8Ń23  0 `   Option2.Submit,nolaterthan1yearafterthe \ effectivedateofthe8hourdesignations,anearly X incrementofprogressplantowardthe8hourNAAQS   whichprovides:8Ń݌` ` (#` (# Ќ  "L"  L#0 ` 23  0 ` (#` (#  A5percentincrementofreductionfromthe2002  \  emissionsbaseline(NOxand/orVOC).Thecontrol   measuresforachievingthisincrementmustbein d  additiontomeasures(orenforceablecommitments `  tomeasures)intheSIPasoftheeffectivedate   ofdesignationandinadditiontonationalor h regionalmeasures.(TheStatecantakecreditfor d thisincrementofreductiontowarditsRFP  requirementunderthe8hourNAAQS.)L#P݌l (# (# Ќ  "L"  L30 ` 23  0 ` (#` (#  Forachievementoftheemissionsreductionswithin h 2yearsaftersubmittal(i.e.,3yearsafter  designation).L3`݌p  (# (# Ќ  "8"  8Œ23  0 `   Option3.Submitanearly8hourozoneattainment !l" demonstrationSIP1yearaftertheeffectivedateof "$ designationforthe8hourNAAQSthat:8Œ݌t$&` (#` (# Ќ  "9<"  9<0 ` 0 ` (#` (#23  0 (# (#  Demonstratesattainmentofthe8hourNAAQS  &p!( bytheareasattainmentdate,9<3݌'#*(#(# Ќ  "9<"  9?@ ` AsnotedaboveintheROPsection,webelievethe `  statuteisambiguousregardingtheneedforStatesto   addressplanningforaNAAQSnolongerneededtoprotect h publichealth.However,sincetheseplanningSIPsresultin d theadoptionofcontrolmeasures,whichwebelieveCongress  intendedbenolessstringent,weexaminedwhatapproaches l wouldensurecontrolsareadoptedandimplementedwithout h unnecessarilyobligatingStatestoplanforaNAAQSnot  neededtoprotectpublichealth. p   ` UnlikeplanningforROP,preparinganattainment !l" demonstrationinvolvescomplexmodelingandanalysesthat "$ canberesourceintensivebothintermsofworkloadand t$& cost.Wedontbelieveitisappropriateornecessaryto  &p!( mandatethatStatesperformtheattainmentdemonstrationfor '#* aNAAQSthatisnotneededtoprotectpublichealth.Butwe  alsodonotbelieveitisappropriatetowaiveintotalthis \ obligationinlightoftheneedtoensurethereisnodelay X inachievingemissionsreductionstoprotectpublichealth.   WeareadoptinganapproachthatprovidesStateswith `  optionsbecauseitprovidesmaximumflexibilitytoStates  \  thathaveoutstandingattainmentdemonstrationobligations   whilecontinuingtoobtaininatimelyfashionmanyorall d  oftheemissionsreductionsthatshouldoccurunderthose `  obligations,effectinganorderlytransitiontoplanning   underthe8hourNAAQS.Inaddition,wedonotbelieveit h isequitabletorelievetheseareasofthisobligationwhere d otherareashavealreadyadoptedcontrolstomeetthese  obligationsandwillnotbeabletomodifyorremovesuch l controlsunlesstheStatecandemonstratethatsuchaction h isconsistentwithsection110(l).   ` Thus,inbalancingCongressionalintenttoensureno p  backsliding,equitabletreatmentofallareas,theneedfor !l" areastobeginplanningforthe8hourNAAQSandthelimited "$ planningresourcesthatStateshaveavailable,webelieve t$& thebestapproachistoprovideStateswithseveral  &p!( alternatives,eachofwhichwillachieveemissions '#* reductionsonatimeframesimilartowhentheywouldhave x)$, beenachievedforthe1hourNAAQSthrougha1hour $+t&. attainmentdemonstrationSIP.TheStatemaychoosethe  optionthatisleastburdensomeinlightofactivities \ alreadyperformed.Forexample,Stateswitha1hour X attainmentdemonstrationthatispastdueorisdueinthe   nextseveralmonthsmayhavealreadymadesignificant `  progressindevelopinga1hourattainmentdemonstration  \  SIP.Thus,theseStatemaychoosethefirstoption.Weare   awarethatoneormoreStateshavealreadybeguntheprocess d  ofdeveloping8hourattainmentdemonstrationsforsome1 `  hournonattainmentareas.TheseStatesmaychoosetosubmit   anearly8hourattainmentdemonstrationSIP.Otherareas, h whichhavenotyetmadesignificantprogresson1houror8 d hourattainmentplanning,maywishtoreservemoretimefor  theattainmentdemonstrationprocess,whichcaninvolve l complexmodeling,andthuschoosethethirdoption!to h achieveanearlyincrementofprogress.   ` ForthesecondoptionavailabletoStates,wechose5! p  ratherthan10!percentastheamountofreduction.Under !l" thisoption,Statesmustachievethe5percentemission "$ reductionfromlocalcontrols(notcurrentlyrequiredbythe t$& SIP)andwithin3yearsofdesignationforthe8hourNAAQS.  &p!( Inlightofthequicktimeframeinwhichtoachievethe '#* reductionsfollowingdesignationsandthelimitationthat x)$, suchreductionscannotbefromregionalornationalcontrols $+t&. orfrommeasuresalreadyintheSIP,weconcludedthat10  percentwasundulyburdensome.TheStatesthatchoosethis \ optionwillneedtoidentifyandadoptappropriatecontrols X withina1yeartimeframeandrequiresourcestoimplement   thecontrolswithinashorttimethereafter.These `  limitationswillrestrictthecontrolchoicesavailableto  \  States.Inaddition,becauseofthelimitedtimeframefor   adoptionandsubmissionofthecontrolstoEPA,wedonot d  believeitisreasonabletorequiretheStatetoobtaina `  levelofreductionthatwouldforcetheStatesto   concentrateitsresourcesontheearlyROPreductionrather h thanonan8hourattainmentplan.However,becausethe d Statewillnotbeabletorelyonnationalorregional  controls,weareconfidentthatthe5percentrequirement l willachievetheantibackslidinggoal. h  ` Finally,aswiththe1hourROPrequirement,wenote  thatEPAmaywaivethe1hourattainmentdemonstration p  requirementforareasbasedonadeterminationthatthearea !l" hasattainedthe8hourNAAQS.TheEPAsCleanData "$ Policy' C  35      ׀providesthatifEPAhasdeterminedthatanarea t$& hasattainedthe1hourNAAQS,itwillnotbeobligatedto  submita1hourattainmentdemonstrationforsolongasit \ maintainsthe1hourNAAQS.Thus,extendingthispolicyto X the8hourNAAQS,ifEPAdeterminesthatanareahas   attainedthe8hourozoneNAAQSbeforethetimetheareais `  obligatedtomakeasubmissionunderthisportionofEPAs  \  8hourimplementationregulations,EPAwouldwaivethis   requirementforsolongasthearearemainsinattainment d  withthe8hourNAAQS.(TheEPAwilladdressthe `  applicabilityoftheCleanDataPolicyfor8hourozone   nonattainmentareasinPhase2oftheimplementationrule.) h  ` (3)Commentsandresponses d COMMENT:Severalcommentersadvocatedretainingthe  planningobligationsunderthe1hourNAAQS,expressingthe l beliefthatmomentumwillbelostinimplementingcontrols h iftheseobligationsarenotretained.Ingeneral,mostof  thesecommentersalsoopposedrevocationofthe1hourNAAQS p  andbelievedCongressintendedthe1hourNAAQStobe !l" plannedforandmet.Somecommentersopposedretainingthe "$ attainmentdemonstrationrequirementsunderthe1hourNAAQS t$& aftertheNAAQSisrevokedonthebasisthatStateresources  &p!( arelimitedandshouldbefocusedondevelopingplansfor '#* implementingthe8hourratherthanthe1hourNAAQS. Afew x)$, commentersfavoredthealternativeofrequiringanearly $+t&. planwithanadvanceincrementofemissionsreductions  towardprogressofthe8hourNAAQSinlieuofthe \ attainmentdemonstrationSIPrevision.Afewother X commentersfavoredthealternativeofrequiringStatesto   submitanearlyattainmentdemonstrationSIPforthe8hour `  NAAQS.  \   ` Onlyonecommenterbelievedthat10percentwasthe   appropriateamountunderAlternative1foranadvance d  incrementofprogress;severalothersopposed10percent, `  claimingthatitappearedtobepunitive,thattherewasno   technicalsupportforthatamount,andthatitmaybemore h thanwhatwasneededforattainmentofthe8hourNAAQS. d  ` Somecommentersrecommendedthatexceptionsbemadefor  anyareathatmadegoodfaitheffortstodevelopandsubmit l itsplan,suchasthosewithasubmittedandapprovedplan h thatmayhavebeenchallengedandoverturnedbyacourt.  RESPONSE:Wehavedesignedthefinalrulesuchthatanarea p  withoutanapprovedattainmentdemonstrationorROPplan !l" wouldstillberequiredtosubmitandimplementaROPplan "$ andanattainmentdemonstrationorsubstituteplanas t$& requiredforthe1-hourNAAQS.Webelievethisapproach  &p!( willensuretherearenodelaysinachievingemissions '#* reductionsaswetransitiontothemorestringent8hour x)$, ozoneNAAQS. $+t&.  ` Webelievethatareasthathavenotmettheirplanning  obligationsunderthe1-hourNAAQS!ifrelievedofthat \ obligationafterthe1-hourNAAQSisrevoked!wouldprovide X emissionsreductionsonamoreprotractedtimeschedulethan   areasthathadmettheir1-hourNAAQSplanningobligations. `  Forexample,anareathatisclassifiedsevere-15forthe  \  1-hourNAAQSwouldhavetoobtainRFPreductionsandany   additionalreductionsneededforattainmentbytheendof d  2005,whereasifthatsameareaismoderateunderthe8-hour `  NAAQS,itwouldnotberequiredtoobtainreductionsunder   theRFPprovisionsuntil2008andadditionalreductionsfor h attainmentbysometimein2009.Webelievethatthe d provisionsofthefinalrule!byofferingthreealternative  meansofmeetingthe1-hourattainmentdemonstration l obligation!allowsufficientflexibilityforaStatein h thesecircumstancestochoosethemostappropriatemeansto  achievethesereductionsinthetimeintendedbyCongress. p  d.Section51.905(a)(2):8hourNAAQSNonattainment/1hour !l" NAAQSMaintenance "$  ` IntheJune2003proposal,wediscussedthe t$& requirementsforareasdesignatedasattainmentforthe1  &p!( hourNAAQSwithamaintenanceplanatthetimeof '#* designationforthe8hourNAAQSinthesamesections x)$, discussingtherequirementsforareasdesignated $+t&. nonattainmentforthe1hourNAAQSatthetimeof8hour  designations.However,inthedraftregulatoryprovisions, \ wecreatedaseparatesubparagraphaddressingtheseareas. X Below,weindicatebrieflywheretheobligationsforthese   areas,i.e.,maintenanceareasatthetimeofdesignation, `  arethesameasforareasdesignatednonattainmentforthe  \  1hourNAAQSatthetimeof8hourdesignations.Wediscuss   inmoredetailwheretheobligationsdiffer. d   ` (i)MandatoryControlMeasures.(sectionVI.C.3.a.i. `  ofproposedrule;see68FR32821;sections51.900(f)and   51.905(a)(2)ofdraftandfinalrules) h  ` (A)Background.IntheJune2003proposal,we d proposedthatallareasdesignatednonattainmentforthe8  hourNAAQSandthatwerenonattainmentormaintenancefor l the1hourNAAQSatthetimeof8hourdesignationswouldbe h requiredtocontinuetoimplementmandatorymeasuresadopted  intotheapprovedSIP.Wedidnotdistinguishbetweenareas p  designatednonattainmentforthe1hourNAAQSatthetimeof !l" designationforthe8hourNAAQSandareasthatare "$ maintenanceforthe1hourNAAQSatthetimeofdesignation t$& forthe8hourNAAQS.However,inthedraftregulatory  &p!( text,wecreatedaseparateprovisionformaintenanceareas '#*  becausetheseareasdonothaveanoutstandingobligationto x)$, adoptmandatorycontrolobligationsforthe1hourNAAQS.) C  36      ׀   Thus,thedraftregulatoryprovisionformaintenanceareas \ didnotaddressthefutureadoptionofcontrols;itsimply X providedthattheseareaswouldberequiredtocontinueto   implementtheapplicablerequirements(asdefinedinthe `  regulatorytext)intheapprovedSIP.  \   ` WealsoprovidedintheJune2003proposalandthe   draftregulatorytextthatifamaintenanceareahad d  previouslyshiftedamandatorycontrolmeasuretothe `  contingencyprovisions,theareawouldnotberequiredto   beginimplementationofthatmeasurebasedonthe8hour h nonattainmentdesignation.However,themeasurewouldneed d toremainasacontingencymeasurefortheareaandcould  notberemovedfromtheSIP. l  ` (B)FinalRule.Weareadoptingtheapproachwetook h intheproposalandthedraftregulatorytext.Areasthat  aremaintenanceforthe1hourNAAQSatthetimeof8hour p  designationsandaredesignatednonattainmentforthe8hour !l" NAAQS,mustcontinuetoimplementmandatorycontrol "$ requirements(i.e., applicablerequirements)thathave t$& beenapprovedintotheSIP.However,sincemaintenance  &p!( areasdonothaveanyoutstandingobligationtoadopt '#* mandatorycontrolmeasuresforthe1hourNAAQS,the  provisiononlyaddressesimplementation,notadoption.In \ addition,thissectionrecognizesthatmaintenanceareashad X theflexibilitytomovemandatorycontrolstothe   contingencymeasuresportionoftheirmaintenanceplan.The `  areawouldnotberequiredtoimplementthesemeasures  \  unlessitisrequiredtodosofortheareasclassification   forthe8hourNAAQS.However,themeasureswouldneedto d  remainascontingencymeasuresandcouldnotberemovedfrom `  theSIP.    ` Weareadoptingtherequirementthat1hourmaintenance h areasarerequiredtocontinuetoimplementmandatory d controlsforthesamereasonsweprovidedwithrespectto8  hourNAAQSnonattainment/1hourNAAQSnonattainmentareas l above.WithrespecttomandatorymeasuresthattheState h hasmovedtothecontingencyportionofthemaintenance  plan,wedonotbelievethatCongressintendedtorequire p  areastobeginimplementingsuchmeasuresagainbasedonthe !l" promulgationofarevisedNAAQSunlessrequiredbasedonthe "$ areasclassificationfortherevisedNAAQS.Theseareas t$& havefullycompliedwiththeprocessthatCongress  &p!( established!attainmentofthe(thenexisting)NAAQSand '#* redesignationtoattainmentforthatNAAQSbasedonaplan x)$, demonstratingthattheareawillmaintaintheNAAQS.While $+t&. webelievetheseareasshouldnot backslidefromexisting  controllevels,wedonotbelievethatforpurposesofthe \ 8hourNAAQStheyshouldberequiredtobeginimplementing X oncemoremeasuresthattheStatehaschosentoplaceinthe   contingencymeasuresportionoftheSIP. `   ` (ii)DiscretionaryControlmeasures.(Section  \  VI.C.3.a.ii.ofproposedrule,see68FR32821,Section   51.905(a)(2)ofdraftregulatorytext;thereisnoparallel d  provisioninthefinalrule.) `   ` (A)Background.TheJune2,2003proposaldidnot   discusstherequirementsfortheseareasindependentofall h areasthatweredesignatednonattainmentforthe1hour d NAAQSonorafterNovember15,1990.Thedraftregulatory  text(section51.905(a)(2)),however,didprovideforthis l situationseparatelybutdidnotdirectlyaddress h discretionarymeasures.   ` (B)Summaryoffinalrule.Aswithdiscretionary p  controlmeasuresfor8hourNAAQSnonattainment/1hourNAAQS !l" nonattainmentareas,1hourNAAQSmaintenance/8hourNAAQS "$ nonattainmentareaswillretainthediscretiontomodifyany t$& discretionarycontrolmeasuresuponademonstrationunder  &p!( section110(l).Wearenotpromulgatingregulatorytext '#* because,asdescribedabove,sections110(l)and193ofthe x)$, CAAgovernsuchSIPrevisions. $+t&.  ` (iii)Measurestoaddressgrowth.(Section  VI.C.3.a.iiiofproposedrule;see68FR32821;sections \ 51.900(f)and51.905(a)(1)ofthedraftandfinalrules) X  ` (A)Background.Intheproposal,werecognizedthat   1hourmaintenanceareasgenerallyaresubjecttothe `  preventionofsignificantdeterioration(PSD)programand  \  arenolongerimplementingthenonattainmentNSRprogramfor   theirprevious1-hourozonedesignationand d  classification.+ C  37      ׀ForareaswheretheNSRprogramnolonger `  appliesundertheSIP,weproposedthattheareaswouldnot   needtorevertbacktotheNSRprogramtheyhadforpurposes h ofthe1-hourNAAQS.Theproposalprovidedexamplesofhow d thiswouldwork(68FR32821).   ` (B)Summaryoffinalrule.Weareadoptingthe l approachweproposedbutourrationalereliesonthefinal h rulesprovisionthatNSRunderthe1hourstandardwillno  longerapplyasofrevocationofthe1hourstandard.Ifan p  areahasbeenredesignatedtoattainmentforthe1hour !l" NAAQSasoftheeffectivedateofthe8hournonattainment "$ designationandisnolongerrequiredtoimplementa t$& nonattainmentNSRprogram,theareawillnotberequiredto  revertbacktotheprogramithadforpurposesofthe1hour \ ozoneNAAQS.Asnotedelsewhere,NSRoffsetratiosand X sourceapplicabilityprovisionsunderthe1hourstandard   arenotbeingdefinedas applicablerequirementsafterthe `  1hourstandardisrevoked.  \   ` Asprovidedinmoredetailbelowfor8hourNAAQS   nonattainment/1hourNAAQSnonattainmentareas,wehave d  determinedthat1hourNAAQSNSRshouldnotcontinueto `  applyoncethe1hourNAAQSisrevokedforthoseareas.It   wouldnotbereasonabletorequiretheseareastobegin h those1hourprogramsagainforthe1yearbetween d designationforthe8hourNAAQSandrevocationofthe1  hourstandard.Moreover,Congressdidnotintendthe l nonattainmentNSRprogramtocontinuetoapplytomostareas h oncetheyareredesignatedtoattainment.Rather,such  areasaresubjecttothePSDprogram.Foranareathathas p  metthecleanairgoalsforthe1hourNAAQS,weseeno !l" reasontorequiresuchareatorevertbacktoits1hourNSR "$ program.Theseareaswillberequiredtoimplementthe t$& nonattainmentNSRprogramthatappliesbasedontheir  &p!( classificationforthe8hourozoneNAAQS. '#*  ` (iv)PlanningSIPs.(SectionVI.C.3.a.iV.ofproposed x)$, rule,see68FR32822;nospecificprovisionindraft $+t&. regulatorytextorfinalrule.)   ` (A)Background.IntheJune2003proposal,wedid \ notdiscussmaintenanceareasseparatefrom8hourNAAQS X nonattainment/1hourNAAQSnonattainmentareas.However,   thepreamblediscussionfocusedonareaswithanoutstanding `  obligationtosubmita1hourROPorattainmentplanandthe  \  obligationtoensurethattheROPpercentagereduction   obligationsintheapprovedSIPareachieved.Maintenance d  areasforthe1hourNAAQSdonothaveanoutstanding `  obligationtosubmitROPorattainmentplansforthe1hour   NAAQS.Thus,thedraftregulatorytextdidnotinclude h languagesimilartothatin51.905(a)(ii)and(iii)for d maintenanceareas.Thedraftregulatorytextdidreflect  ROPasanapplicablerequirementformaintenanceareas, l indicatingthattheseareasmustensurethatanySIP h revisiondoesnotinterferewithanapprovedROPmilestone.   ` (B)Summaryoffinalrule.Weareadoptingthe p  approachtakeninthedraftregulatorytext.In !l" redesignatinganareatoattainment,EPAmustconcludethat "$ theareahasmetallrequirementsapplicableundersection t$& 110andpartD.Thus,maintenanceareasdonothave  &p!( continuingprogressandattainmentdemonstration '#* requirements,andthefinalruledoesnotestablish x)$, requirementsformaintenanceareasrelatedtooutstanding $+t&. attainmentdemonstrationandROPplans.Thefinalruledoes  identifytheROPpercentreductionrequirementasan \ applicablerequirement.However,wenotethattheROP X periodsforareasredesignatedtoattainmentforthe1hour   NAAQShavealreadypassedandthusanyrevisiontotheSIP `  shouldnotaffectROPreductionsfortheperiodsrequired  \  forthe1hourNAAQS.    ` (C)Commentsandresponses d  COMMENT:Onecommenterbelievedthat1hourmaintenance `  areasdesignatednonattainmentunderthe8hourNAAQSshould   nothavetosubmitupdatestothe1hourmaintenanceplan, h sincetheywillbedeveloping8hourattainmentplansthat d willsubsumetherequirementsofthemaintenanceplan  previouslyineffect. l RESPONSE:Theruleprovidesthatafterthe1hourozone h NAAQSisrevoked,areasarerelievedofresponsibilitiesto  submitupdatestotheir1hourmaintenanceplans.TheState p  maysubmitarevisiontotheSIPtoremovetheprovisions !l" thatrequiretheupdatetothemaintenanceplan. "$ COMMENT:OnecommenternotedthatdraftSection t$& 51.905(a)(2)wouldlimitshiftingofanapplicable  &p!( requirementtothecontingencymeasureportionofanareas '#* maintenanceplan.Undertheproposal,aStatemayonlymake x)$, suchashiftpriortotherevocationofthe1hourNAAQS; $+t&. Statesmayonlymakesubsequentshiftsbysatisfyingthe  requirementsofSection110(l)oftheCAA.Thecommenter \ believesthatthiscriterionforshiftingmeasurestothe X maintenanceplanismorestringentandburdensomethanthe   requirementsinSection175AoftheCAAformaintenance `  plans.Inthealternative,thecommenterrecommendsthatin  \  lieuoftheshowingrequiredbySection110(l),thatStates,   instead,beallowedtosubstituteacontrolmeasurewith d  equivalentemissionsreductionsforthemeasuresthey `  proposetoremovefromtheirplan.   RESPONSE:Weagreewiththecommenterthatsection h 51.905(a)(2)willlimittheauthorityofanareathatwas d maintenanceforthe1hourstandardatthetimeof  designationasnonattainmentforthe8hourstandard. l However,wedisagreewiththecommenterregardingthe h statutoryprovisionsthatapplyforpurposesofSIP  revisions.Thecommenterisincorrectthatsection110(l) p  doesnotapplytorevisionstomaintenanceplans.Priorto !l" beingdesignatednonattainmentforthe8hourNAAQS,suchan "$ areacouldmoveadoptedmeasurestothecontingencymeasures t$& portionofthemaintenanceplanbasedonademonstration  &p!( undersection110(l)thatsucharevisionwouldnot '#* interferewithattainment,maintenanceoranyother x)$, applicablerequirementoftheCAA.Ourruleprovidesthat $+t&. upondesignationasnonattainmentforthe8hourNAAQS,a1  hourmaintenanceareawillnotbeabletoshiftadopted \ mandatorycontrols(i.e.,thoseidentifiedas applicable X requirementsintheregulation)tocontingencymeasuresas   thoseobligationsarenowdefinedas applicable `  requirements.Oncetheareaisredesignatedtoattainment  \  forthe8hourNAAQS,suchobligationswillnolongerbe   definedas applicablerequirementsandtheStatecanmove d  themtocontingencymeasuresbasedonademonstrationthat `  todosowouldnotinterferewithattainmentormaintenance   ofthe8hourNAAQSoranyotherapplicablerequirementof h theCAA.Foradoptedcontrolmeasuresthatarenot d identifiedas applicablerequirementsintheregulation,  theStatewillcontinuetohavethesameauthorityit l currentlyhasforshiftingadoptedcontrolstocontingency h measures,basedonademonstrationundersection110(l).  COMMENT:Onecommenternotedthatinsection51.905(a)(2), p  theclause ...excepttotheextentrequiredunderits8 !l" hourobligations...couldbeinterpretedtoimplythat "$ contingencymeasuresinthe1hourmaintenanceplanbecome t$& 8hourmeasuresbydefault.Thecommentersuggested  &p!( languagetoavoidanincorrectinterpretation. '#*  RESPONSE:Thefinalrulereflectsthisrecommendedlanguage x)$, changewithsomeslightmodifications. $+t&. e.Section51.905(a)(3):8HourNAAQSAttainment/1Hour  NAAQSNonattainment \  ` (i)Mandatorycontrolobligations.(SectionVI.C.3.b. X ofproposalsee68FR32823;section51.905(a)(3)(i)ofthe   draftandfinalrule) `   ` (A)Background.Theproposalnotedthattheissueof  \  whatobligationremainswithrespecttomandatorycontrol   measuresapprovedintotheSIPorrequiredundertheCAAis d  basedontheCAAsrequirementsformaintenanceplans.2XcXX XcWe `  proposedthatifEPAdeterminedthattheseareaswere   requiredtodevelopmaintenanceplanspursuanttosection h 175A,thentheywouldneedtokeep(ortoadoptandthen d keep)thosecontrolmeasuresintheSIP,thoughtheycould  shiftthemtocontingencymeasures.f  Ԁf  # XcXX2Xc#XXX Xc l  ` # XcXXX來#2XcXX Xcf  g f  g Forf  g anf  g areaf  g Ԁthatf  g f  g wasf  g Ԁneverredesignatedtoattainment h forthe1hourstandardandneverhadf  g af  g section175A  maintenanceplanf  g ,weproposedthatf  g f  g iftheareaf  g Ԁwantf  g sf  g Ԁto p  reviseanyf  g partf  g off  g f  g itsf  g Ԁcurrent1hourf  g f  g SIP,theareamust !l" firstadoptf  g f  g Ԁandsubmitf  g af  g maintenanceplanf  g Ԁconsistentwith "$ section110(a)(f  1)(discussedbelow)g .# XcXX2Xc!#ԀWeproposedthatthese t$& obligationswouldremaininplacebutinalatersectionof  &p!(  thepreambleproposedoptionsastowhenthisobligation '#* wouldnolongerapply.- C  38      ׀    ` (B)Summaryoffinalrule. \  ` Weareadoptinganapproachconsistentwithour X proposedrule.Aswediscusslaterinthispreamble,we   havedeterminedthatmandatorycontrolobligationswillno `  longerapplyonceanareaattainsthe8hourNAAQS.Thus,  \  becausetheseareasareattainingthe8hourNAAQS,the   Statemayrequestthatobligationsundertheapplicable d  requirementsofsection51.900(f)beshiftedtocontingency `  measuresoncethe1hourNAAQSisrevoked,consistentwith   sections110(l)and193oftheCAA.However,theState h cannotremovetheobligationsfromtheSIP. d  ` Becausetheseareasareinattainmentwiththehealth  basedNAAQS,webelievethatCongress!aswithareas l redesignatedfromnonattainmenttoattainment!didnot h intendtheareastoretainthesecontrolsasimplemented  measuresiftheareacandemonstratemaintenancewithoutthe p  controls.Aswithareasredesignatedtoattainment,the !l" ruleprovidesthattheStatecannotremovethemeasuresfrom "$ theSIP,butrathermaymovethemtothecontingency t$& measuresportionoftheSIP.Wedidnotreceivecomments  &p!( directlyaddressingmandatorycontrolobligationsforthis '#* categoryofareasoutsidethecontextofmaintenanceplans  fortheseareasdiscussedbelow. \  ` (ii)Discretionarycontrolobligations.(Section X VI.C.3.b.iii.ofproposal;68FR32823;section51.905(d)of   draftregulatorytext;noparallelprovisioninfinalrule.) `   ` Areasdesignatednonattainmentforthe1hourNAAQS  \  thataredesignatedattainmentforthe8hourozoneNAAQS   willretaintheabilitytomodifyanydiscretionarycontrols d  uponademonstrationundersection110(l).However,such `  controlsmustremainintheSIPascontingencymeasures.We   arenotpromulgatingregulatorytextbecause,asdescribed h above,sections110(l)and193oftheCAAgovernsuchSIP d revisions2XcXX Xc.# XcXX2Xc͖#Aswithmandatorymeasures,welooktothe  maintenanceplanprovisionofsection175Atoseewhat l Congressintentmayhavebeenfortheseareas.Because h theseareaswerenonattainmentforthe1hourNAAQS,we  believeCongressintendedthemtoretainthemeasuresinthe p  SIP,butcouldshiftthemtocontingencymeasuresifthe !l" areademonstratesitwillmaintainthe8hourNAAQSifthe "$ measureisnolongerimplemented.Wedidreceivecomments t$& directlyaddressingdiscretionarycontrolobligationsfor  &p!( thiscategoryofareasoutsidethecontextofmaintenance '#* plansfortheseareasdiscussedbelow. x)$,  ` (iii)Measurestoaddressgrowth.(Section $+t&. VI.C.3.b.i.ofproposal;68FR32823;noprovisionindraft  orfinalrule.) \  (88 ` (A)Background.TheproposalexplainedthatNSR X appliesonlyinnonattainmentareas.Q C  39      ׀Sincetheseareas   wouldbedesignatedattainmentforthe8hourNAAQS!the `  onlyozoneNAAQSthatexistsfortheareaoncethe1hour  \  NAAQSisrevoked!theywouldbesubjecttoPSD,notNSR,   oncethe1hourNAAQSisrevoked. d   ` (B)Summaryoffinalrule.Weareadoptingthe `  approachwesetforthinourproposedruleforareas   designatedattainmentforthe8hourNAAQSanddesignated h nonattainmentforthe1hourNAAQSatthetimeof d designationforthe8hourNAAQS.Afterthe1hourNAAQSis  revoked,theCAArequiressuchareastocomplywithPSD,not l NSR.(TheStatesmayneedtomodifytheirSIPssothatit h providesforPSDratherthanNSRinsuchareas.)Wedonot  seeabasisformandatingthatsuchareasretaina p  nonattainmentNSRprogramanddonotbelievethatCongress !l" intendedsucharesult.Asaninitialmatter,oncethe1 "$ hourNAAQSisrevoked,theseareasaremeetingtheonly t$& ozoneNAAQSthatisinplace.CongressspecifiedthatPSD  shallapplyinareasnotdesignatednonattainment(section \ 161oftheCAA).Inaddition,asprovidedinmoredetail X belowfor8hourNAAQSnonattainment/1hourNAAQS   nonattainmentareas,wehavedeterminedthat1hourNAAQS `  NSRshouldnotcontinuetoapplyoncethe1hourNAAQSis  \  revokedforthoseareas.     ` Notethatfortheseareas,theNSRprovisionsmaybe d  removedfromtheSIPandneednotbeshiftedtocontingency `  measures.S C  40      Wehaveneverinterpretedsection175Aofthe   CAAtomandatethatnonattainmentNSRberetainedasa h contingencymeasureintheSIPafteranareaisredesignated d fromnonattainmenttoattainmentbecausewedonotinterpret  NSRtobeacontrolmeasure.(See,e.g.,May12,2003;68 l FR25436.) h  ` (C)  COMMENT:Somecommentersbelievedthatthe1hourNAAQS p  shouldremainineffect,andthereforeNSRwouldcontinueto !l" applyuntiltheareaattainsthe1hourNAAQSandis "$ redesignatedtoattainmentforthatNAAQSregardlessofthe t$& areasstatusforthe8hourNAAQS.Othercommenters  &p!( generallyagreedwiththeproposal.  RESPONSE:Weaddressthebroaderlegalandpolicyissues \ regardingrevocationofthe1hourNAAQSintherevocation X sectionofthisrule.    `  (iv)PlanningSIPs.(SectionVI.C.3.b(ii)of `  proposedrule;see68FR32823;Section51.905(a)(3)(ii)of  \  draftandfinalrule.)    ` (A)Background.IntheJune2,2003proposedrule, d  weproposedthatanyoutstandingSIPplanningrequirements `  (ROPplansandattainmentdemonstrations)thatappliedfor   purposesofthe1-hourNAAQSwouldnotcontinuetoapplyto h areasdesignatedattainmentforthe8hourNAAQSforaslong d astheycontinuetomaintainthe8-hourNAAQS.Ifsuchan  areaviolatesthe8-hourNAAQSpriortohavinganapproved l maintenanceplanmeetingtherequirementsofsection h 110(a)(1)theobligationtohavea1hourattainment  demonstrationandROPplanwouldonceagainapplyinthe p  samemannerthattheyapplyfor8hourNAAQS !l" nonattainment/1hourNAAQSnonattainmentareas. "$  ` Thedraftregulatorytext(section51.905(a)(3)) t$& containedspecificprovisionsaddressingtheobligationfor  &p!( anareadesignatedattainmentforthe8hourNAAQSthat '#* subsequentlyviolatesthe8hourNAAQSpriortohavingan x)$, approvedmaintenanceplanundersection110(a)(1).Ifthe $+t&. areawasrequiredtoanddoesnothaveanapproved  attainmentdemonstrationorROPplanforthe1hourNAAQS, \ theStatewouldberequiredtosubmitaplanprovidingfora X 10percentemissionreductionasasubstituteforthe   attainmentdemonstrationandtoadoptandsubmitany `  outstandingROPemissionreductions.  \   ` (B)Summaryoffinalrule.Weareadoptingour   proposalwithsomemodification.Asaninitialmatter, d  section51.905(a)(3)nowonlyaddresses8hourNAAQS `  attainment/1hourNAAQSnonattainmentareas.Wehave   createdanewsection51.905(a)(4)thataddresses8hour h NAAQSattainment/1hourNAAQSmaintenanceareas.The d sectionaddressingthatsecondcategoryofareasis  discussedbelow.Anareathatis8hourNAAQSattainment/1 l hourNAAQSnonattainmentwillnotberequiredtodevelopand h submitoutstandingattainmentdemonstrationandROPplans  f  g f  g f  g forthe1hourNAAQSforsolongastheareacontinuesto p  maintainthe8hourNAAQS.However,iftheareaviolates !l" the8hourNAAQSpriortohavinganapproved8hour "$ maintenanceplanundersection110(a)(1),theareawillbe t$& requiredtosubmitaSIPrevisiontoaddressoutstandingROP  &p!( andattainmentdemonstrationplansasfollows.U C  41       '#*  ` (1)2XcXX Xc ROPPlans. Foranoutstanding1hourROPplan,  theStatemustsubmitaSIPprovidingforanyoutstanding x ROPandthe3yearperiodsforachievingthosereductions $t willbeginJanuary1oftheyearfollowingthe3yearperiod   onwhichEPAbasesitsdetermination.Forexample,ifan |  areawasrequiredtoanddoesnothaveanapprovedSIP ( x  providingfora9%reductioninemissionsfrom19961999, $  theobligationtohavesuchaSIPisdeferredunlessthe   areaviolatesthe8hourNAAQSpriortohavinganapproved ,|  maintenanceplanforthe8hourNAAQS.IfEPAdeterminesin ( August2007thattheareaviolatedthe8hourNAAQSbasedon  ambientairqualitydatafrom20042006andatthattimethe 0 areadoesnothaveanapprovedmaintenanceplanforthe8 , hourNAAQS,theareawillberequiredtosubmitaSIP  providingfora9percentreductioninemissionsforthe3 4 yearperiodofJanuary2007December2009.TheStatemay 0 relyonnationalandregionalcontrolsforpurposesof   meetingthisincrementofreductionandthe9percentshould 8!" becalculatedusingthe1990baseline.(The1hourROP "4$ requirementiscalculatedfroma1990baseline,nota2002 $& baseline,asisthe8hourRFPrequirement.)Wehave <&!( clarifiedthelanguageinthefinalregulationtomakeclear '8#* thattherequirementtosubmittheplanforadditional )$, emissionreductionsappliesonlytotheextentthatanarea @+&. hadnotmetitspriorplanningobligations.Forexample,if  anareawasclassifiedasseriousforthe1hourNAAQSand \ hadanapproved15percentROPplanandanapproved9 X percentROPplanfor19961999,thentheareadoesnothave   anyoutstandingROPobligationthatmustbemetunderthis `  provision.However,ifthesameareaonlyhadanapproved  \  15percentROPplan,butnotanapproved9percentROPplan   for19961999,thentheareahasanoutstanding9percent d  ROPplanforthe19961999period.IftheStatehad `  submittedtheROPplantoEPA,butEPAhadnotyetactedon   thesubmission,theStatemaynotifyEPAthatitwishesto h relyonthepreviouslysubmittedSIPoritmayelectto d submitaneworrevisedSIP.   ` Webelievethisapproachmakessenseasitensuresthat l thelevelofemissionreductionthattheareawasrequired h toachieve,butwasnotyetenforceableundertheSIP,will  beachievedexpeditiouslyafteraviolationofthe8hour p  NAAQSoccurs.# XcXX2Xc# !l"  ` (2) AttainmentDemonstration. Foranoutstanding1 "$ hourattainmentdemonstration,thefinalrulerequiresthe $& Statetoeither:(1)submitan8hourmaintenanceplanthat <&!( addressestheviolationanddemonstratesmaintenancethrough '8#* EPAapprovedmodeling;or(2)submitaplantoachievea3 )$, percentincrementofprogresswithin3yearsafterEPA @+&. determinestheareahasviolatedtheNAAQS.The3percent  incrementofprogressmustbeinadditiontomeasures(or \ enforceablecommitmentstomeasures)intheSIPatthetime X oftheeffectivedateofdesignationandinadditionto   nationalorregionalmeasures. `   ` ThisapproachdiffersfromboththeJune2003proposal  \  andthedraftregulatorytextinthatwedonotestablish   preciselythesamerequirementfortheseareasthatwe d  establishforareasthatare8hourNAAQSnonattainment/1 `  hourNAAQSnonattainment.Forareasthatare8hourNAAQS   nonattainment/1hourNAAQSnonattainment,section h 51.905(a)(1)(ii)providesthreeoptionsfortheState.The d firstoptionavailableisthatStatesmaychoosetosubmit  their1hourSIP.Wedonotbelievethisoptionmakesgood l policysenseforanareadesignatedattainmentforthe8 h hourNAAQStospendresourcestodevelopaplantoachieve  the1hourNAAQS(whichislikelytohavebeenrevokedby p  thattime),whentheareawillalreadybeintheprocessof !l" developingthesection110(a)(1)maintenanceplanforthe "$ areadiscussedelsewhereinthispreamble. t$&  ` Thesecondandthirdoptionsundersection  &p!( 51.905(a)(1)(ii)availabletoareasthatare8hourNAAQS '#* nonattainment/1hourNAAQSnonattainmentareanalogousbut x)$, notidenticaltothetwooptionsweprovideforareas $+t&. designatedattainmentforthe8hourNAAQS.Bothtypesof  areasareprovidedwiththeoptionofachievingaspecified \ incrementofprogress.Forareasthatare8hourNAAQS X nonattainment/1hourNAAQSnonattainment,weestablishedan   incrementof5percentandforthosedesignatedattainment `  forthe8hourNAAQS,weestablisheda3percentincrement.  \  Ingeneral,webelievethatthoseareasinitiallydesignated   attainmentforthe8hourNAAQSwillhavealesssignificant d  8hourproblem!theseareastendtorecordvalueswithina `  fewpartsperbillionoftheNAAQS.Thus,sincethe   incrementofprogressislimitedtocontrolsnotalready h adoptedintotheSIPorrequiredbyfederalorregional d controls,the5percentreductionrequirementwouldlikely  beexcessiveforpurposesofaddressingthatsmalldeviation l fromtheNAAQS. h  ` Thethirdoptionavailabletoareasthatare8hour  NAAQSnonattainment/1hourNAAQSnonattainmentistosubmit p  anearly8hourattainmentdemonstration.Sinceareas !l" designatedattainmentforthe8hourNAAQSarenotrequired "$ todevelopattainmentdemonstrations,itdidnotmakesense t$& tocarrythisoptionover.Rather,wedetermineditmade  &p!( moresensetoallowtheareatoaddresstheviolationinthe '#* contextoftheobligationthatitdoeshave,i.e.,to x)$, developamaintenanceplanforthe8hourNAAQS.Thus,for $+t&. theseareas,wecreatedtheoptionofperformingamore  rigorousmaintenancedemonstration!ademonstrationbased \ onEPAapprovedmodeling. X  ` (C)Commentsandresponses.   COMMENT:Somecommentersondraftregulatorytextobjected `  tocontinuingtheobligationforareastosubmitROPplans  \  and/orattainmentdemonstrationsforthe1hourNAAQSafter   the1hourNAAQSisrevoked.Someofthecommentsreflected d  thefactthattheregulatorytextmayhavebeenunclear `  regardingwhattherequiremententailedandwhichareaswere   affected.   h RESPONSE:Wehavedesignedthefinalrulesuchthatanarea d withanunmetplanningobligationwouldstillberequiredto  submitandimplementarateofprogressplanandan l attainmentdemonstration(orsubstituteplan)underthe h 1-hourNAAQSiftheareaviolatesthe8hourNAAQSbeforeit  hasanapprovedmaintenanceplan.Theseareareasthathave p  historicallyhadanozoneproblemand,ingeneral,have8 !l" hourdesignvalueswithinafewpartsperbillionofthe8 "$ hourNAAQS.Oncetheseareashaveanapproved110(a)(1) t$& maintenanceplanwithcontingencymeasures,thatplanwill  &p!( addressfutureviolationsofthe8hourNAAQSandthe1hour '#* obligationswillnolongerapply.However,untilthatplan x)$, isinplace,webelievethatCongresswouldhaveintended $+t&. theserequirementstostillhavesignificanceifthearea  violatesthehealthbasedNAAQS. \  ` Thefinalregulatorytextwasmodifiedtoclarifythat X theprovisionappliestoareasthatdonothaveapprovedROP   plansand/orattainmentdemonstrationsunderthe1hour `  NAAQSandthatviolatethe8hourNAAQSbeforehavingan  \  approved8hourmaintenanceplanundersection110(a)(1).   Theregulatorytextalsoclarifiestheobligationthatwill d  apply. `   ` (v)MaintenancePlansforthe8hourNAAQS.(Section   VI.C.3.b(iii)ofproposedrule;see68FR32823;Section h 51.905(a)(3)(iii)ofdraftandfinalrules) d  ` (A)Background   ` IntheJune2003proposal,weproposedthatareas l designatedattainmentforthe8hourNAAQSanddesignated h nonattainmentforthe1hourNAAQSonorafterNovember15,  1990,mustadoptf  g f  g Ԁandsubmitf  g af  g maintenanceplanf  g Ԁconsistent p  withsection110(a)(f  1)g Ԁf  g within3yearsofdesignationas !l" attainmentforthe8hourNAAQS.f  g Thef  g Ԁmaintenanceplanf  g Ԁshould "$ provideforg continuedf  g maintenanceofthe8hourNAAQSfor10 t$& yearsfollowingf  g f  g f  g designationforthe8hourNAAQSf  g f  g Ԁandmust  &p!( includecontingencymeasures.f  g f  g Areaswithapproved1hour '#* maintenanceplansundersection175Awouldbeabletomodify x)$, thosemaintenanceplansconsistentwiththeirobligationto $+t&. haveamaintenanceplanforthe8hourNAAQSundersection  110(a)(f  1f  ).Suchareascouldremovefromtheirmaintenance \ SIPsf  Ԁ(a)g f  g f  f  g theobligationtosubmitamaintenanceplanforthe X 1hourNAAQS8yearsafterapprovaloftheirinitial1hour   maintenanceplan;f  f  g f  g Ԁand(b)f  g f  g therequirementtoimplement `  contingencymeasuresuponaviolationofthe1-hourozone  \  NAAQS.    ` Thedraftregulatorytextreflectedthedescriptionin d  theJune2003proposal. `   ` (B)Summaryoffinalrule    ` Weareadoptingtheapproachweproposed.However,as h notedabove,wehavenowcreatedseparatesubsectionsinthe d ruleaddressingareasthatweredesignatednonattainmentfor  the1hourNAAQSatthetimeofdesignationforthe1hour l NAAQSandareasthatweremaintenanceareasforthe1hour h NAAQSatthetimeofdesignationforthe8hourNAAQS.  Section51.905(a)(3)(iii)appliesonlytoareasdesignated p  nonattainmentforthe1hourNAAQSatthetimeof !l" designationforthe8hourNAAQS.Section51.905(a)(4)(ii) "$ establishesthesamerequirementforareasthatare t$& maintenanceforthe1hourNAAQSatthetimeofdesignation  &p!( forthe8hourNAAQS.Thesetwoprovisionsprovidethat1 '#* hourNAAQSnonattainment/8hourNAAQSattainment(section x)$, 51.905(a)(3)(iii))and8hourNAAQSattainment/1hourNAAQS $+t&. maintenance(section51.905(a)(4)(ii))areasmustadoptf  g f  g Ԁand  submitf  g af  g maintenanceplanf  g Ԁconsistentwithsection110(a)(f  1)g  \ f  g within3yearsofdesignationasattainmentforthe8hour X NAAQS.f  g ԀThef  g Ԁmaintenanceplanf  g Ԁshouldprovideforg continued   f  g maintenanceofthe8hourNAAQSfor10yearsfollowing `  f  g f  g f  g designationforthe8hourNAAQSf  g f  g Ԁandshouldinclude  \  contingencymeasures.Weprovideadditionaldetailbelow   regardingmaintenanceareasforthe1hourNAAQS. d   ` Section110(a)(1)requiresallareastodemonstrate `  thattheywillattainandmaintaintherelevantNAAQS.Most   oftheareasaddressedbythisprovisionoftheregulation h havehistoricallyhadproblemsmeetingand/orremainingin d attainmentoftheozoneNAAQS.Wethinkitisimportantfor  Statestoensurethattheseareaswillcontinuetohave l cleanairsothatthehealthofcitizenswillbeprotected. h  ` (C)Commentsandresponses  COMMENT:Anumberofcommenterswhoaddressedthisissuein p  commentsontheJune2,2003proposaldidnotsupportthe !l" section110(a)(1)maintenanceplanrequirement.Some "$ commentersbelievedthe1hourNAAQSshouldremainineffect t$& andwithitanyexisting1hourSIPrequirements,including  &p!( section175Amaintenanceplanrequirements(whichwould '#* requireconformitydeterminations).Onecommenterobjected x)$, totheproposedrequirement,allegingtherequirementwas $+t&. unnecessaryandnotrequired.Twocommentersagreedwith  therequirement. \  ` Incommentingonthedraftregulatorytextone X commentersupportedthisprovision.Onecommenter   recommendedthatweprovidemorespecificguidanceon `  preparationofsection110(a)(1)maintenanceplansandalso  \  notrequiremodelingforthem.Twocommentersobjectedto   maintenanceplansundersection110(a)(1)becausetheywould d  notrequireconformity(aswouldmaintenanceplansunder `  section175A)forareasthatcurrentlyhavemaintenance   plansunderthe1hourNAAQS.Thecommentersbelievedthe h maintenanceplanningshouldbedoneundersection175A. d Anothercommenterbelievedthatsection110(a)(1)oftheCAA  requiresneithercontingencymeasuresnora10yearplan; l thecommentersuggestedthatthesection110(a)(1) h maintenanceplanmerelybeacontinuationoftheprovisions  oftheexistingmaintenanceplan. p  RESPONSE:2XcXX XcBecausethe1hourNAAQSwouldberevoked,the !l" requirementsofsection175Awouldnotapplytotheseareas "$ (areasinitiallydesignatedattainmentforthe8hourNAAQS t$& butthatweredesignatednonattainmentforthe1hourNAAQS  &p!( atthetimeofenactmentofthe1990CAAAmendments.) '#* Section175Aappliestoredesignations,nottoinitial x)$, designations.Afterthe1-hourNAAQSisrevoked,webelieve $+t&. thatanareathatwaspreviouslydesignatednonattainment  forthe1-hourNAAQSorwasdesignatedattainmentwitha \ maintenanceplanandthatinitiallyisdesignatedattainment X forthe8hourozoneNAAQS,shouldberequiredto   demonstratemaintenanceonlyforthe8-hourNAAQSatthat `  point.Theareawasnot redesignatedattainmentforthe  \  8-hourNAAQS,andthereforethesection175Amaintenance   planrequirementdoesnotapply.Webelievethatthe d  section110(a)(1)maintenanceprovisions!asrequiredin `  section51.905!willprovideadequateassuranceof   maintenanceofthe8hourNAAQS.TheEPAalwaysretainsthe h authoritytorequireaStatethatfailstomaintainthe d NAAQStoreviseitsSIPtoprovideadditionalmaintenance  measuresortoredesignatetheareanonattainmentand l requireanattainmentdemonstration. h  ` Wedonotagreewithcommentersthatopposeda  provisionrequiringamaintenanceplanundersection p  110(a)(1)fortheseareas.WebelievethattheCAArequires !l" thatSIPscontinuetoprovideformaintenanceofthe "$ applicableNAAQSundersection110(a)(1).Becausethese t$& areashavehistoricallyexperiencedozoneproblemsand  &p!( generallyareclosetoviolatingthe8hourNAAQS,we '#* believeitisprudenttorequireademonstrationofhowthey x)$, willmaintainthe8hourNAAQS.Wethinkthisrequirement $+t&. willbenefitcitizensbyprovidingbetterassurancethatthe  airwillremaincleanandwillbenefitindustryby \ minimizingthelikelihoodtheareawillviolatethestandard X andberedesignatedtononattainment.   f.# XcXX2Xc0#Section51.905(a)(4):8HourNAAQSAttainment/1Hour `  NAAQSMaintenance  \   ` Asnotedabove,inthepreambletotheproposedrule,   EPAaddressedinthesamesection1hournonattainmentareas d  and1hourmaintenanceareasthataredesignated `  nonattainmentforthe8hourNAAQS.Commentsonthe   proposedregulatorytextnotedthatsection51.905(a)(3) h onlyaddressed8hourattainmentareasthatweredesignated d nonattainmentforthe1hourozoneNAAQSandnotareasthat  weremaintenanceforthatNAAQS.Thus,thedraftruledid l notaddressallaspectsoftheproposalsinceitdidnot h includeprovisionsforareasthataremaintenanceforthe1  hourNAAQSatthetimeofdesignations. p   ` Weconsideredrevisingparagraph51.905(a)(3)to !l" include1hourmaintenanceareas.However,thatsubsection "$ includedcertainrequirementsnotrelevantfor1hour t$& maintenanceareas,suchasrequirementsconcerning  &p!( outstandingattainmentdemonstrationandROPplans.Thus, '#* inthefinalrule,wecreatedsection51.905(a)(4)toapply x)$, toareasdesignatedattainmentforthe8hourNAAQSandthat $+t&. weremaintenanceareasforthe1hourNAAQSatthetimeof  designationforthe8hourNAAQS. \  ` (i) ObligationsinanapprovedSIP.(51.905(a)(4)(i)). X  ` Thissubsectionisidenticalinstructuretosection   51.905(a)(3)(i).Ourreasonsareexplainedinour `  discussionofsection51.905(a)(3)(i),above.  \   ` (ii)Maintenanceplan.(51.905(a)(4)(ii).As   providedaboveinthediscussionofsection d  51.905(a)(3)(iii),weareadoptinginourfinalruleour `  proposedinterpretationregardingmaintenanceplansfor   areasdesignatednonattainmentforthe1hourNAAQSonor h afterNovember15,1990(i.e.,areasthatremaindesignated d nonattainmentforthe1hourNAAQSaswellasmaintenance  areasforthe1hourNAAQSatthetimeofdesignationfor l the8hourNAAQS).Specifically,theseareasmustadopta h maintenanceplanundersection110(a)(1)within3yearsof  designationforthe8hourNAAQS.Theprovisionfor p  maintenanceareasisthesameasforareasdesignated !l" nonattainmentforthe1hourNAAQS.However,for "$ maintenanceareas,section51.905(e),discussedbelow, t$& crossreferencesthisprovisionandaddressesthe  &p!( relationshipbetweentheexisting1hourmaintenanceplan '#* andthe8hourmaintenanceplan. x)$,  ` Ourreasonsforadoptingthisprovisionarediscussed $+t&. above.Althoughtheseareasalreadyhavemaintenanceplans,  thoseplansonlyaddressmaintenanceofthe1hourNAAQS. \ Itisimportantfortheseareastoensurethattheyhavea X planaddressingmaintenanceofthe8hourNAAQS.These   areasmayevaluatetheirexistingplananddemonstratehow `  itwillensuremaintenanceofthe8hourNAAQS,ormay  \  modifytheirexistingplan,ormayadoptanewplan,as   appropriate. d  COMMENT:Onecommenterarguedthatitmakeslittlesenseto `  requiretheStatetocontinuetoexpendtheeffortand   resourcestoupdateandextendthesemaintenanceplans.The h commenterquestionedwhyanewlydesignatedmarginalarea d underthe8-hourNAAQSshouldbeexemptfromimplementation  planrequirements,whileanareapreviouslynonattainment l forthe1-hourNAAQS,butnowinattainmentforbothNAAQS, h shouldberequiredtocontinuewith8additionalyearsof  maintenanceplanrequirements. p  RESPONSE: Thefinalrule(section51.905(a)(4))clarifies !l" thattheseareas(areasthatareinitiallydesignated "$ attainmentforthe8hourNAAQSbutwereattainmentareas t$& underthe1hourNAAQSwithapprovedmaintenanceplans)are  &p!( relievedoftherequirementtoupdatetheirmaintenanceplan '#* undersection175(A),butmustsubmitamaintenanceplan x)$, undersection110(a)(1)thatprovidesformaintenancefor10 $+t&. years.Itshouldbenotedthatmarginalareasunderthe8  hourNAAQSarenot exemptfromimplementationplan \ requirements;theyarestillsubjecttononattainmentnew X sourcereviewandconformityrequirements,forinstance.   Furthermore,ifamarginalareadoesnotattaintheNAAQSby `  itsattainmentdate,theCAArequiresthattheareabe  \  bumpedupinclassification,whichwouldrequiretheareato   submitarevisedSIPwithanattainmentdemonstrationand d  controlmeasuresrequiredundersubpart2fortheareasnew `  classification.Inaddition,oncetheareaattainsthe8   hourNAAQS,itwillbesubjecttothemorestringent h maintenanceplanprovisioninsection175A,whichrequires d theareastodemonstratemaintenancefor20years.   3.Forhowlongdotheseobligationscontinuetoapply? l (SectionVI.C.4ofproposedrule;see68FR32824;section h 51.905(b)ofdraftandfinalrules)  a.Background.IntheJune2,2003proposedrule,we p  proposedtwooptionsforwhentheStatewouldnolongerbe !l" requiredtocontinueimplementingSIPapprovedcontrol "$ obligationsrequiredforanareas1hourclassification. t$& Atthattime,theserequirementscouldberelegatedtothe  &p!( contingencymeasuresportionoftheSIPiftheState '#* demonstratedthatimplementationofthecontrolswasnot x)$, necessarytoattainormaintainthe8hourNAAQS(consistent $+t&. withsection110(l)).Forsimplification,werefertothis  asthetimecontrolobligationsmaybeshiftedtothe \ contingencymeasures.Weclarifiedthattheterm control X obligationswasintendedtorefertotheobligationswhich   wedeterminedwouldcontinuetoapplyunderthepreceding `  sectionsoftheproposal,includingtheNOxtransportrules.  \  UnderOption1,controlobligationscouldbeshiftedto   contingencymeasureswhentheareaachievesthelevelofthe d  1-hourozoneNAAQS(eveniftheareahasnotyetattained `  the8-hourNAAQS).UnderOption2,controlobligations   couldbeshiftedtocontingencymeasuresoncethearea h attainsandisredesignatedtoattainmentforthe8hour d NAAQS(regardlessofwhen,ifever,theareaattainsthe  1-hourNAAQS).Thedraftregulatorytextwasdeveloped l usingOption1(whentheareaachievesthelevelofthe1 h hourozoneNAAQS).  b.Summaryoffinalrule.WeareadoptingOption2! p  controlobligationsanareaisrequiredtoretaininthe !l" approvedSIPforanareas1hourclassificationmust "$ continuetobeimplementedundertheSIPuntilthearea t$& attainsandisredesignatedtoattainmentforthe8hour  &p!( NAAQS.Atthattime,theStatemayrelegatesuchcontrols '#* tothecontingencymeasureportionoftheSIPiftheState x)$, demonstratesinaccordancewithsection110(l)thatdoingso $+t&. willnotinterferewithmaintenanceofthe8hourNAAQSor  anyotherapplicablerequirementoftheCAA.Ifatthetime \ theareaisredesignatedtoattainmentforthe8hourNAAQS X theStatehasanoutstandingobligationtoadoptacontrol   requirementunderthe1hourNAAQS,itremainsobligatedto `  doso,butmayadoptitasacontingencymeasure.As  \  discussedabove,underEPAsCleanDataPolicy,certain   obligationssuchastherequirementtosubmitROPplansand d  attainmentdemonstrationsmaybesuspendedbasedona `  determinationthattheareahasattainedthe8hourNAAQS   andwillnolongerapplyiftheareaisredesignatedto h attainment.However,ifanareaexperiencesaviolationof d the8hourNAAQSpriortobeingredesignatedtoattainment  therequirementswouldonceagainapply.  l   ` Weareadoptingthisoptionbecause,asnotedinthe 4 June2,2003proposal,the8-hourNAAQSistheNAAQSthatwe 0 havedeterminedwillprotectpublichealthandthe   environment.Onlyonceanareademonstratesithasmetand 8!" canmaintainthehealthprotectiveNAAQSdowebelieveit "4$ willbeappropriatetoshifttheseobligationstothe $& contingencymeasuresportionoftheSIP.Thisschemeis <&!( consistentwithwhatCongressintended.TheCAA '8#* contemplatesundersubpart2thatStatesmustimplement )$, certainmandatedrequirements.Underthemaintenanceplan @+&. provisionoftheCAA(section175A),suchrequirementsmay  beshiftedtothecontingencymeasureportionoftheSIP \ uponorafterredesignationtoattainment.Sincethe X relevantNAAQSisnowthe8hourNAAQS,webelieveitis   appropriatetorequirethesemandatedcontrolstoremainas `  partoftheimplementedSIPuntilanareaattainsthe8hour  \  NAAQSandisredesignatedtoattainment.Onorafterthat   date,aStatemaymovesuchobligationtothecontingency d  measuresportionoftheSIPconsistentwithsections175A `  and110(l).Moreover,webelieveitisappropriatetouse   attainmentofthe8hourNAAQSratherthanattainmentofthe h 1hourNAAQSbecause,asprovidedelsewhereinthis d rulemaking,EPAwillnolongerbemakingdeterminationsof  whetheranareahasattainedthe1hourNAAQSandareaswill l notberequiredtodemonstrateattainmentormaintenanceof h the1hourNAAQS.Someareasmayneverattainthe1hour  NAAQS,astherewillbenoobligationtodosoonceitis p  revoked. !l"  ` Thefinalrulecoversthecontinuedapplicabilityof "$ theNOxtransportrulesundersection51.905(f),ratherthan t$& asan applicablerequirementforpurposesofsection  &p!( 110(l)becausetheNOxrulesapplyregardlessofanareas '#* attainmentornonattainmentstatusforthe8hour(orthe1 x)$, hour)NAAQS. $+t&. c.Commentsandresponses  COMMENT:Ofthefewcommenterswhoaddressedthisissuein \ responsetotheJune2,2003proposal,severalfavored X Option1,andseveralfavoredOption2.Ofthosewho   commentedonthedraftregulatorytext,onecommenter `  opposedtheprovision,andonecommentwasunclearastothe  \  commentersconcerns.Oneothercommentersupportedthe   provision.Severalcommentershadclarifyingquestions. d  RESPONSE:OurrationaleforthechoiceofOption2is `  presentedabove.Amoredetailedresponsetotheseand   othercommentsappearsintheRTCdocument. h 4.Whichportionsofanareadesignatedforthe8hour d NAAQSremainsubjecttothe1hourNAAQSobligations?  (SectionVI.C.2and3ofproposal;see68FR3282032821; l 51.905(c)ofthedraftandfinalrules) h a.Background.IntheJune2,2003notice,weproposed  thattheobligationtoretainortoadoptandretaina p  mandatorycontrolobligationappliesonlytothepartofthe !l" 8-hourozonenonattainmentareathatwasdesignated "$ nonattainmentforthe1-hourozoneNAAQS.Theproposalalso t$& providedanexampleofhowthiswouldwork.  &p!(  ` Thedraftregulatorytextprovidedadditional '#* specificityconcerninggeographicapplicabilityoftheanti x)$, backslidingprovisions.Thedrafttextprovidedthatwith $+t&. twoexceptionsonlytheportionofthedesignatedareafor  the8hourNAAQSthatwasrequiredtoadopttheapplicable \ requirementsin51.900(f)forpurposesofthe1hourNAAQS X issubjecttotheobligationsidentifiedinparagraph(a)of   thissectionwithseveralexceptions.Thefirstexception `  isanareathatisdesignatednonattainmentforthe8hour  \  NAAQSbutthatwasnonattainmentforthe1hourNAAQSwith   anunmetobligationtosubmitanattainmentdemonstration; d  fortheseareas,thedraftregulatorytextprovidedthatthe `  entireareadesignatednonattainmentforthe8hourozone   NAAQSwouldbesubjecttothe10percentadvanceincrement h ofreduction.Thesecondexceptionisanareathatis d attainmentforthe8hourNAAQSbutthatwasnonattainment  underthe1hourNAAQSwithanunmetobligationtosubmitan l attainmentdemonstration;fortheseareas,the110(l) h maintenanceplanwouldhavetodemonstratemaintenancefor  theentire8hourozoneattainmentarea. p  b.Summaryoffinalrule.Thefinalruleincorporatesmost !l" aspectsoftheapproachasthatcontainedintheproposal "$ andinthedraftregulatorytext.Thefinalruleprovides t$& thatonlytheportionofthedesignatedareaforthe8-hour  &p!( NAAQSthatwasdesignatednonattainmentforthe1-hourNAAQS '#* isrequiredtocomplywiththeobligationsinsubparagraph x)$, 51.905(a),exceptiftheStateelectstoprovideanearly $+t&. incrementofprogressoranearly8-hourattainment  demonstrationinlieuofanoutstanding1-hourattainment \ demonstration(foran8hourNAAQSnonattainmentarea/1hour X NAAQSnonattainmentareaunder51.905(a)(1)(ii)(B)and(C)),   theincrementofprogressorearly8-hourattainmentplan `  mustapplyforpurposesoftheentire8-hournonattainment  \  area.    ` Thefinalruledoesnotfollowtheapproachinthe d  proposalforthemaintenanceplanrequirementfor8hour `  attainmentareas.Themaintenanceplansrequiredunder   section51.905(a)(3)(iii)and(4)(ii)mustdemonstrate h maintenanceonlyfortheareadesignatednonattainmentfor d the1hourNAAQSatthetimeofdesignationofthe8hour  NAAQS.Wereceivedcommentthatrecommendedthisobligation l applyonlytotheareathatwasoriginallydesignated h nonattainmentforthe1-hourNAAQS.Afterconsideringthis  commentandourdiscussioninthepreambletotheproposed p  rule,weagreewiththecommenter.InmanyStates, !l" attainmentareasareidentifiedcountybycountyratherthan "$ identifyingagroupofcountiesasanattainmentarea. t$& Thus,aStatemayhaveoneormoregroupsofcountieslisted  &p!( asanonattainmentareaandthentheremainingcountiesin '#* theStateareeachidentifiedindividuallyas"attainment." x)$, Seee.g.,40CFR81.311(Georgia);81.329(Nevada).Because $+t&. theareathathistoricallyhadaproblemattainingtheozone  NAAQSistheareathatwaspreviouslydesignated \ nonattainmentforthe1-hourNAAQS,webelieveitmakesthe X mostsensetorequirethemaintenanceplanforthearea   previouslydesignatednonattainmentforthe1-hourNAAQS. `  Wewillsetforthin40CFRPart81,SubpartE,an  \  identificationoftheboundariesofareasandthearea   designationsandclassificationsforthe1-hourNAAQSatthe d  timeofthe8-hourdesignations. `  2XcXX Xcc.Commentsandresponses   COMMENTSONJUNE2,2003PROPOSAL:Withregardtolimiting h theapplicabilityof1hourobligationstothatportionof d the8hournonattainmentareathatwasalsopartofthe1  hournonattainmentarea,onecommentersupportsthispolicy, l especiallyfortheenhancedI/Mprogram.Thecommenter h believesthattheenvironmentalbenefitofrequiringan  extensionoftheenhancedI/Mprogramtoareasrecently p  addedtotheCMSAanddesignatednonattainmentforthe8 !l" hourNAAQStobeminimal,costly,anddisruptiveofthe "$ continuedimplementationoftheenhancedI/Mprograminthe t$& current1hournonattainmentarea.  &p!(  ` Onecommenterobjectedtorequiringthesubstitute '#* planningrequirement(10percentadvanceincrementof x)$, emissionreductions)thatappliestoareaswithan $+t&. outstandingattainmentdemonstrationfortheentire8hour  ozonenonattainmentarea.Instead,thecommenter \ recommendeditshouldonlyapplytothe1hournonattainment X area.   RESPONSE:# XcXX2XcK#2XcXX XcThefinalruleprovidesforretainingapplicable `  emissioncontrolrequirementsforanareas1hour  \  classificationinonlytheoriginal1hournonattainment   area. d   ` Asnotedinthefinalrulemakingnotice,wearenow `  allowingtheStatetomeetitsunmet1-hourattainment   demonstrationobligationbysubmittingtheoutstanding h attainmentdemonstrationorbytakingoneoftwoearly d actionsfor8hourplanning:achievea5percentadvance  incrementofemissionreductionsorsubmitanearly8hour l attainmentdemonstration.Theadvanceincrementofemission h reductionsisappliedthroughouttheentire8-hour  nonattainmentareabecause,althoughitisbeingsubmitted p  inlieuofthe1hourrequirement,itisintendedtoaddress !l" the8-hournonattainmentproblem.Similarly,the8hour "$ attainmentdemonstrationisintendedtoaddressattainment t$& forthefull8hourarea.Becausethesealternativestothe  &p!( 1hourattainmentdemonstrationareintendedtoaddress '#* attainmentandprogresstowardthe8-hourNAAQS,theState x)$, wouldneedtoapplytheserequirements,ifselected,tothe $+t&. entire8-hournonattainmentarea.Wedevelopedthese  alternativesinresponsetoconcernsthatareasfocusonthe \ 8hourNAAQSratherthanonthe1hourNAAQSandthat X continuedplanningobligationsforthe1hourNAAQSwould   burdenStateresources.Statesstillhavetheflexibility `  tochoosetodevelopthe1hourattainmentdemonstrations  \  forthe1hourareaiftheywouldliketorestricttheunmet   planningobligationtotheoldarea. d  5.Whatobligationsthatappliedforthe1hourNAAQSwill `  nolongerapplyafterrevocationofthe1hourNAAQSforan   area?(SectionVI.C.3.d.ofproposal;see68FR32824; h Section51.905(e)ofproposedandfinalrules) d a.BackgroundIntheJune2,2003proposedrule(68FR  328224),weproposedthatoncethe1hourNAAQSisrevoked, l EPAwouldnolongermakefindingsoffailuretoattainthat h NAAQSand,therefore,wewouldnotreclassifyareasbased  uponafindingthattheareafailedtoattainthe1hour p  NAAQS.Weindicatedareasshouldfocustheirresourceson !l" attainmentofthe8-hourNAAQSandstatedthatwebelieved "$ itwouldbecounterproductivetoestablishnewobligations t$& forStateswithrespecttothe1-hourNAAQSaftertheyhave  &p!( begunplanningforthe8-hourNAAQS.Inaddition,wenoted '#* thattheattainmentdatesforareasclassifiedasmarginal, x)$, moderateandserioushadpassedandthattheCAAdoesnot $+t&. provideforreclassificationofsevereareas.Wealsonoted  othermechanismsthatareavailabletomakesurethatStates \ continuetomakeprogresstowardattainingthe8hourNAAQS. X  ` Inaddition,weindicatedthatconformityrequirements   wouldnolongerapplyforthe1hourNAAQSoncetheNAAQSis `  revoked.TheJune2,2003proposalexplainsthat,under  \  section176(c)oftheCAA,conformityappliestoareas   designatednonattainmentorsubjecttotherequirementto d  developamaintenanceplanpursuanttosection175A.Once `  the1-hourNAAQSisrevoked,areasf  g wouldnolongerbe   f  g designatedf  g f  g nonattainmentf  g Ԁforthef  g f  g 1hourf  g ԀNAAQSf  g Ԁorsubjectto h theobligationtodevelopamaintenanceplanundersection d 175Aforthe1hourNAAQSandthusf  g Ԁwouldnolongerbe  subjecttotheobligationtodemonstrateconformity(either l transportationconformityorgeneralconformity)forthat h NAAQS.   ` Thedraftregulatorytextincorporatedtheseconcepts p  andalsoprovidedthat,atthetimeofrevocationofthe1 !l" hourNAAQS,anyprovisionsofapplicableSIPsthatrequire "$ conformitydeterminationsinsuchareasforthe1-hourNAAQS t$& willnolongerbeenforceableasamatteroflawpursuantto  &p!( section176(c)(5)oftheCAA. '#*  ` Additionally,thedraftregulatorytextreflectedthe x)$, discussioninthepreambletotheproposedruleregarding $+t&. whatportionsofa1hourmaintenanceplancouldberevised  orremovedoncethe1hourNAAQSwasrevoked(68FR32823). \ Thedraftregulatorytextprovidedthatareaswithapproved X 1hourmaintenanceplanscouldmodifythoseplanstoremove   theobligationtosubmitamaintenanceplanforthe1hour `  NAAQSeightyearsafterapprovaloftheinitial1hour  \  maintenanceplanandtoremovetheobligationtoimplement   contingencymeasuresuponaviolationofthe1hourNAAQS. d  Thedraftregulatorytextprovided,however,thatthese `  requirementswouldremainenforceableuntilEPAapproveda   SIPremovingorrevisingthemandalsoprovidedthatEPA h wouldnotapprovesuchrevisionsuntilEPAapprovesan8 d hourattainmentdemonstrationforanareadesignated  nonattainmentforthe8hourNAAQSoran8hourmaintenance l planforanareadesignatedattainmentforthe8hourNAAQS. h Finally,EPAnotedthatsuchaSIPrevisionmustalsobe  consistentwithsections110(l)and193oftheCAA. p  b.Summaryoffinalrule !l"  ` Weareadoptingtheapproachwesetforthinour "$ proposedruleandprovidingclarificationregardingthe t$& penaltyobligationsundersections181(b)(4)and185Aofthe  &p!( CAAthatapplyinsevereareasthatdonotattainthe1hour '#* NAAQSbytheapplicableattainmentdate.Thefinalrule x)$, providesthatasoftheeffectivedateofrevocationofthe $+t&. 1hourNAAQS:  ec  ec