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V 8Document[6]Document Style8..V 8Document[5]Document Style0..V/8Document[2]Document Style 2A.3  Ԁ   V& 8Document[7]Document Style0..0` ..` zU :Right Par[1]Right-Aligned Paragraph Numbers..2I.3  Ԁ..0..zh :Right Par[2]Right-Aligned Paragraph Numbers..` ..2A.3  Ԁ..0` ..` V?8Document[3]Document Style.. 21.3  Ԁ   z{ :Right Par[3]Right-Aligned Paragraph Numbers..` ..`  ..P 21.3  Ԁ` ..` 0 .. z :Right Par[4]Right-Aligned Paragraph Numbers..` ..`  .. .. 2a.3  Ԁ .. 0..z :Right Par[5]Right-Aligned Paragraph Numbers..` ..`  .. ..h..2(1)3  Ԁ..0h..hz :Right Par[6]Right-Aligned Paragraph Numbers..` ..`  .. ..h..h..2(a)3  Ԁh..h0..z :Right Par[7]Right-Aligned Paragraph Numbers..` ..`  .. ..h..h....2i)3  Ԁ..0..z :Right Par[8]Right-Aligned Paragraph Numbers..` ..`  .. ..h..h....p..2a)3  Ԁ..0p..pVX8Document[1]Document Style  @..^  2I.3  Ԁ     Ԉ l2:Technical[5]Technical Document Style.. 2(1)3  Ԁ. l2:Technical[6]Technical Document Style.. 2(a)3  Ԁ. l/%:Technical[2]Technical Document Style 2A.3  Ԁ   .. l,!:Technical[3]Technical Document Style 21.3  Ԁ   .. l(!:Technical[4]Technical Document Style 2a.3  Ԁ   .. l:0:Technical[1]Technical Document Style  2I.3  Ԁ     .. l1:Technical[7]Technical Document Style.. 2i)3  Ԁ. l1:Technical[8]Technical Document Style.. 2a)3  Ԁ. l36EPA.STY[5]EPA Style with TOC marking..2(1)3  Ԁl06EPA.STY[6]EPA Style with TOC marking..2(a)3  Ԁ.l 6EPA.STY[3]EPA Style with TOC marking  21.3  Ԁ  lD!6EPA.STY[1]EPA Style with TOC marking  @..SECTION2I.3  Ԉ@..   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A. a.(1)(a) i) a)S234($0 ($0 0 (($0 0 0   A_ekqwDocumentDocument StyleI.1.A.a.(1)(a)i)a)jo4Tech InitInitialize Technical StyleS 7  1 .1 .1 .1 .1 .1 .1 .1 S CuyTechnicalTechnical Document Style11.11.1.11.1.1.11.1.1.1.11.1.1.1.1.11.1.1.1.1.1.11.1.1.1.1.1.1.1x?3u2PleadingHeader for numbered pleading paper 9  :(   "mXX"XXX?E;'*dE*??E;'*dE*?HH1HH2HH3HH4HH5HH6HH7HH8HH910111213141516171819202122232425262728  .+('2$ DT!   $" ##""Xd#(O$$35;AGMU]c4I.A.1.a.(1)(a)i)a),- ?u{EPA.STYEPA Style with TOC markingI.A.1.a.(1)(a)i)a)  CRight ParRight-Aligned Paragraph NumbersI.A.1.a.(1)(a)i)a)#|x<6X9`("Courier 10cpiXx6X@8;X@( T$   dp02HP LaserJet 6P,,,,00d0s "U N'   __  Draft_Ԁ_6__30_04;0 @ Donotquoteorcite((3$ DT!   <4 9Z+ Courier New ($$  0   + uD$  OXXX"XOXXXOX `   1    _See57FR55622( NitrogenOxidesSupplementtothe  GeneralPreamble,publishedNovember25,1992).<Q 9Z+.Courier New Regular<6X9`("Courier 10cpi  uD$  OXXX"XOXXXOX `   9    _Section302(e)oftheActdefinestheterm"person"to  includeStates.(http://www.epa.gov/ttn/scram/).  uD$  OXXX"XOXXXOX `   4    XXXOXWithrespecttoNSR,theEPArecognizedthattheterms  ofexistingNSRregulationsshouldbeadequatetocoverNOx  whereitisconsideredaprecursortotheformationof \ ozone,butproposedtocodifyNOxasanozoneprecursorin 2 ordertobecompletelyclear.68FR32846.#OXXXX#XXXOX#OXXXX=#*+ (_2623  ..   uD$  OXXX"XOXXXOX `   3    _"XXXOX Section182(f)NitrogenOxides(NOx)  Exemptions!RevisedProcessandCriteria#OXXX"Xث#"XXXOX,#OXXX"XZ#Ԁmemorandum"XXXOXfrom x JohnS.Seitz,Director,OfficeofAirQualityPlanningand N Standards,totheRegionalDivisionDirectors,May27,1994#OXXX"Xح#"XXXOX; f and Section182(f)NitrogenOxides(NOx)Exemptions . RevisedProcessandCriteria,#OXXX"Xؓ#memorandum"XXXOXfromJohnS.  Seitz,Director,OfficeofAirQualityPlanningand |  Standards,totheRegionalDivisionDirectors,February8, D  1995#OXXX"Xl#"XXXOX.#OXXX"Xj#"XXXOXԀ#OXXX"Xح#04CEKQW]cioAutoList1a.A.a.a.a.a.a.a.Za.3#37=CIQYag1.a.i.(1)(a)(i)1)a)\i)(;3$2#  0  .3  0  (CEKQW]cioAutoList2A.A.A.A.A.A.A.A._A.*D+J (_25   ," <DL,23  ..  2( 4 <DL2  (O;$0  2#  a  .3  0` (#(#(CEKQW]cioAutoList3A.A.A.A.A.A.A.A.cA.*A+J (_24   ) <DL)23  ..  2( 4 <DL2   A uD$  OXXX"XOXXXOX `   2    _"XXXOXGuidelineforDeterminingtheApplicabilityof  NitrogenOxideRequirementsunderSection182(f),"fromJohn x S._Seitz_,Director,OfficeofAirQualityPlanningand @ Standards,totheRegionalDivisionDirectors,December16, X 1993.#OXXX"Xث#*>+J (_23  ` &<<DL&23  ..  2( 4 <DL2  *;+J (_22   #DL#23  ..  2( 4 <DL2  *8+J (_21    DL 23  ..  2( 4 <DL2  *5+J (_20  h DDL23  ..  2( 4 <DL2  *2+J (_19   L23  ..  2( 4 <DL2  */+J (_18    L23  ..  2( 4 <DL2  * (_1723  Ԁ*DJ (_16   ," <DL,23  Ԁ  2( 4 <DL2  *AJ (_15   ) <DL)23  Ԁ  2( 4 <DL2  *>J (_14  ` &<<DL&23  Ԁ  2( 4 <DL2  *;J (_13   #DL#23  Ԁ  2( 4 <DL2  *8J (_12    DL 23  Ԁ  2( 4 <DL2  *5J (_11  h DDL23  Ԁ  2( 4 <DL2  ((3Z$ DT!     0  .(t(2D$ DT!   OX&XX"XOX&XXOX& `   0  (#$  0  *2J (_10   L23  Ԁ  2( 4 <DL2  (/J &_9    L23  Ԁ  2( 4 <DL2  ( &_823  (DJ &_7   ," <DL,23   2( 4 <DL2  (AJ &_6   ) <DL)23   2( 4 <DL2  (>J &_5  ` &<<DL&23   2( 4 <DL2  (;J &_4   #DL#23   2( 4 <DL2  (8J &_3    DL 23   2( 4 <DL2  (5J &_2  h DDL23   2( 4 <DL2  (2J &_1   L23   2( 4 <DL2  &/J $_    L23   2( 4 <DL2   uD$  OXXX"XOXXXOX `   6    ݀OzoneTransportAssessmentGroup,OTAGFinalReport,  1997.<6X9`(Courier New  uD$  OXXX"XOXXXOX `   7    ݀NARSTO,AnAssessmentofTroposphericOzonePollution  ЄANorthAmericanPerspective,July2000. uD$  OXXX"XOXXXOX `   8    ݀USEPA,TheOzoneReport:MeasuringProgressthrough  2003,April2004. p uD$  OXXX"XOXXXOX `   5    _TheEPAsprimaryguidanceregardingsection182(f)is  containedinthe"GuidelineforDeterminingthe  ApplicabilityofNitrogenOxideRequirementsunderSection \ 182(f),"issuedbyJohnS._Seitz_,Director,OfficeofAir 2 QualityPlanningandStandards,totheRegionalDivision X Directors,December16,1993.  DT!   __M_8""XXdd8_   `     h      p      X   GUIDENACEONLIMITINGNITROGENOXIDESREQUIREMENTS  @ ЀRELATEDTO8HOUROZONEIMPLEMENTATION `  _K_____   `     h   _   `       `     h @*_   __W   `     h DraftJuly2004 &@(   U.S.EnvironmentalProtectionAgency (( * OfficeofAirQualityPlanningandStandards (!+ ResearchTrianglePark,NC27711_  )`", 8""XXd"XXd8____=GUIDANCEONLIMITINGNITROGENOXIDESREQUIREMENTS X RELATEDTO8HOUROZONEIMPLEMENTATION   CONTENTS  X CHAPTERS   10  INTRODUCTION @(#(#   1.1General `  0  1.20` (#(#Section182(f)( ` (#` (#   1.30 ` NitrogenOxidesRequirements ` (#` (#   1.4 ` Section185BStudy `  0  1.5 ` ApplicationofSection182(f)Requirements( (#(#   1.6 ` OrganizationofthisDocument H  2  ADMINISTRATIVEPROCEDURES   0  2.10` (#(#ProcessingwiththeStateImplementationPlan(SIP) H  Revisionh` (#` (# 0  2.2 ` Petition0(#(#   2.30 ` InterfacewiththeSIP` (#` (#   2.40 ` Timingh` (#` (#   2.5 ` Areaswitha1HourOzoneNOxExemption 0 30  NETAIRQUALITYBENEFIT(#(#   3.1 ` Demonstration    3.2 ` Factors P  c(83\"^3"     ` ^3c 2  A  .3  0   OzoneNonattainmentAreas^3c ݌p (# (# Ќ  "^3"     ` ^3] 2  B  .3  0   AreasNonattainmentforbothOzoneandNitrogen 8 Dioxide^3] ݌ (# (# Ќ  "^3"     ` ^3 2  C  .3  0   AreasNonattainmentforbothOzoneandParticulate p Matter^3 ݌8 (# (# Ќ  "^3"     ` ^32  D  .3  0   AreasNonattainmentforOzoneandCarbonMonoxide, X   LeadorSulfurDioxide^3݌ !! (# (# Ќ  "^3"     ` ^32  E  .3  0   SecondaryFactors^3:݌!" (# (# Ќ    3.3 ` GeographicScope "X#   3.4 ` Scenarios x# $   3.5 ` Sources @$% 40  CONTRIBUTETOATTAINMENT%x'(#(#   4.1 ` Demonstration &@(   4.2 ` GeographicScope `' )   4.30 ` ApplicabilitytoAreasMonitoringAttainment(( *` (#` (# 50  NETOZONEAIRQUALITYBENEFIT)`",(#(#   5.1 ` Demonstration *(#-   5.2 ` Factors H+#.   5.3 ` Attainment/UnclassifiedPortions ,$/ 6  EXCESSEMISSIONSREDUCTIONS -H&1 = =8""XXd"XXd8 =    6.1 ` General X   6.2 ` Demonstration   7  MODELINGTECHNIQUES  X   7.1 ` PhotochemicalGridModeling x    7.2 ` RegionalModeling @     `     h 80  EMISSIONSANALYSIS x(#(#   8.1 ` General  @   8.2 ` YearstoAnalyze `    8.3 ` ScenariostoCompare (    8.4 ` ConsistencywiththeSIP     8.5 ` NewSourceReview `     `        = 8""XXd"XXd8р@&CHAPTER1  @$INTRODUCTION @ 1.1General   OXXX"X  #"XXXOX#OXXX"XInsubpart2ofpartD#"XXXOX#oftheCleanAirAct(CAA),as `  amendedin1990OXXX"X,section182(f)requiresStatestoapplythesame 6  requirementstomajorstationarysourcesofnitrogenoxides(NOx)  \ asareappliedtomajorstationarysourcesofvolatileorganic  2  compounds(VOC).Theserequirementsare#"XXXOX#reasonablyavailable    controltechnology(RACT)andnewsourcereview(NSR)OXXX"Xformajor    stationarysourcesincertainozonenonattainmentareasand d  throughoutStatesinthe#"XXXOXK#OzoneTransportRegionOXXX"X.Q v#  1      ׀Inaddition, :  section182(f)specifiescircumstancesunderwhichtheseNOx `  requirementswouldbelimitedorwouldnotapply(NOxexemption). 6  Further,asaresultofrulemaking,areasgrantedaNOxexemption   undersection182(f)maybeexemptfromcertainNOx#"XXXOX0#OXXX"XԀrequirements   relatedtomotorvehicleinspectionandmaintenance,operating h permits,andgeneralandtransportationconformity. > #"XXXOX2#  In1993,EPAissuedaguidancedocumentforapplicationof , thesection182(f)provisionswithrespecttothe1hourozone  standard.f< v#  2      ׀TheNOxexemptionguidanceforthe1hourozone l standard,asrevised,Y v#  3      ׀ continuestoapply.The1hourguidance 4 shouldbeappliedindependentlyfromtheguidanceforthe8hour L ozonestandard.    In1997,EPAestablishedthe8hourozonestandard.OOXXX"XnJune T 2,2003#"XXXOX!#,EPAproposedrulestoimplementthe8hourozone *z standard(68FR32802).OXXX"XԀTheEPAproposedto#"XXXOX"#OXXX"XԀextendtosubpart1 P areastheNOxRACTandNSRrequirementswhichapplytomajor &= stationarysourcesinsubpart2nonattainmentareasand X throughoutanOzoneTransportRegion.#"XXXOX ##OXXX"X_V v#  4      ׀TheEPAalsoproposedto . establishNOxexemptionprovisionsforthe8hourozonestandard   thatreflectthesameconceptsastheexistingguidanceforthe   1hourozonestandard.  X   DecreasesinNOxemissionsgenerallyreduceozonelevelsand \  providesignificantozonerelatedhealthbenefits.Atthelocal 2  level,however,thisisnotalwaysthecase.Duetothecomplex  photochemistryofozoneproduction,emissionsofNOx leadtoboth   theformationanddestructionofozone(O3).Insunlightfree \  radicalsoxidizeNOtoNO2andtheNO2reactswithsunlightto 2  recreateNOandtoproduceO3.TheresultingO3concentration `  depends,inpart,ontherelativequantitiesofNOx(NO+NO2), 6  VOC,andfreeradicals(e.g.,OH).SomecombinationofVOCand    NOxisoptimumatproducingO3.      InareaswithlargeemissionsofNOrelativetoVOC,the 6 reactionbetweenemittedNOandexistingO3removessomeO3 d  (formingNO2andO2).Inaddition,aportionoftheNO2formed : reactswithOHtoproducenitricacid,aformofnitrogenthat  doesnotcreateO3.Inthesecases,decreasesinNOxemissions  resultinalocalincreaseinO3concentrations(NOxdisbenefit). d Thiseffectisusuallyshortlived(local)andmuchoftheNO2 : formedfromthereactionbetweenNOandO3 leadstoformationof h O3later(i.e.,furtherdownwind).Theozoneincreasesthatcan > resultfromNOx#"XXXOXB$#OXXX"XԀemissionsreductionsintheselocalizedareasare  generallylimitedtosmallregionswithinspecificurbancores  andaresurroundedbylargerregionsinwhichNOxcontrolis h beneficial. >   ThispotentialNOx#"XXhOX,#OXXh"XdisbenefitresultedinCongressincluding B! NOxexemptionprovisionsinsubpart2,#"XXXOXh.#OXXX"Xsection182(f) f  g .TheEPA "  believestheNOxexemptionprovisionsareaprudentsafeguardto "! avoidunnecessaryemissionsreductionsandshouldbeextended #l" intosubpart1areas.Therefore,inthe8hourozone $B# implementationruleEPAproposedtoestablishNOxexemption p%$ provisionsforareassubjectf  g tosubpart1g Ԁaswellassubpart2#"XXXOX/#OXXX"Xf  g . F&%  TheEPAproposedthattheconceptscontainedintheexisting1 '& hour#"XXXOXY1#OXXX"Xozoneguidance v#  5      ׀regardingsection182(f)wouldapplyforthe X  8hourozoneprogramundersubparts1and2asdescribedinthis . document.f  f  g      WhilelocalizedozoneincreasescanresultfromNOx  X reductions,itshouldbenotedthatthemostrecentauthoritative  . assessmentsofregionalozonecontrolapproaches v#  6      ,  v#  7      have \  concludedthataNOxcontrolstrategywouldbemosteffectivefor 2  reducingregionalscaleozoneandozonetransport,whereasVOC  reductionsaremosteffectiveinmoredenseurbanizedareas.As   aresult,EPAhasproposedorpromulgatedseveralregulatory \  requirementsoverthepastdecadedesigned,inpart,toreduce 2  regionalNOxemissions:rulesfromtheAcidRainProgram, `  multipleFederalmotorvehicleandoffroadenginestandards,the 6  regionalNOxSIPCallRule,andtherecentlyproposedCleanAir    InterstateRule.Overtimetheserulesareexpectedtoreduce   themagnitudeandthegeographicextentofthenations8hour `  ozoneproblem.Inaddition,EPAhasrecentlyconcluded|  v#  8      ׀that 6 improvementsinozoneairqualityovertheeasternUnitedStates d  sincethemid1990shavecoincidedwithcontinueddecreasesin : NOxemissions,togetherwithlocalVOCcontrolprograms.  #"XXXOX*2#OXXX"X  ThisdocumentdescribesEPA'spreliminaryviewsonhowEPA d woulddeterminethattheNOxrequirementswouldbelimitedor : wouldnotapplyforthe8hourozoneprogramunder_subparts_Ԁ1and h 2.Althoughthisdocumentincludesvariousstatementsthat > Statesorpetitionersmusttakecertainactions,thesestatements  areguidancemadepursuanttoEPA'spreliminaryinterpretations,  andthusdonotbindtheStatesandthepublicasamatterof h law.TheEPA'sinterpretationswillprovideabasisfor > subsequentEPAapprovalordisapprovalofrequestsforexemption X fromtheNOxrequirements.Thisdocumentdoesnotimpose . binding,enforceablerequirementsonanyparty,nordoesit   assurethatEPAmayapproveallinstancesofitsapplication,and   thustheguidancemaynotapplytoaparticularsituationbased  X uponthecircumstancespresented.EPAretainsthediscretionto  . adoptapproachesonacasebycasebasisthatdifferfromthis \  guidancewhereappropriate. 2    AnydecisionsbyEPAregardingaparticulardemonstration   pursuanttosection182(f)willonlybemadefollowingnoticeand \  opportunityforpublicreviewandcomment.Therefore,interested 2  partiesarefreetoraisequestionsandobjectionsaboutthe `  appropriatenessoftheapplicationofthisguidancetoa 6  particularsituation;EPAwillconsiderwhetherornotthe    guidelinessetforthinthisdocumentareappropriateinthat   situation.Thisguidanceisalivingdocumentandmayberevised `  periodicallywithoutpublicnotice.TheEPAwelcomespublic 6 commentsonthisdocumentatanytimeandwillconsiderthose d  commentsinanyfuturerevisionsofthisguidancedocument. : Readersofthisdocumentarecautionednottoregardstatements  recommendingtheuseofcertainproceduresordefaultsaseither  precludingotherproceduresorinformationorproviding d guaranteesthatusingtheseproceduresordefaultswillresultin : actionsthatarefullyapprovable.Asnotedabove,EPAcannot h assurethatactionsbaseduponthisguidancewillbefully > approvableinallinstances,andallfinalactionsmayonlybe  takenfollowingnoticeandopportunityforpubliccomment.#"XXXOX9:#OXXX"X  #"XXXOXE#1.2Section182(f)OXXX"X > #"XXXOX'F#  Section182(f)oftheCleanAirActreadsasfollows: &! ̀NOxRequirements.!(1)Theplanprovisionsrequiredunderthis "^! subpartformajorstationarysourcesofvolatileorganic ~#&" compoundsshallalsoapplytomajorstationarysources(as F$# definedinsection302andsubsections(c),(d),and(e)ofthis %$ section)ofoxidesofnitrogen.Thissubsectionshallnotapply %~% inthecaseofoxidesofnitrogenforthosesourcesforwhichthe &F& Administratordetermines(whentheAdministratorapprovesaplan f' ' orplanrevision)thatnetairqualitybenefitsaregreaterin .( ( theabsenceofreductionsofoxidesofnitrogenfromthesources (!) concerned.Thissubsectionshallalsonotapplyinthecaseof )f"* oxidesofnitrogenfor *.#+ 0  (A)nonattainmentareasnotwithinanozonetransportregion N+#, undersection184iftheAdministratordetermines(whenthe ,$- Administratorapprovesaplanorplanrevision)that ,%. additionalreductionsofoxidesofnitrogenwouldnot -N&/ contributetoattainmentofthenationalambientairquality X standardforozoneinthearea,or (#(# 0  (B)nonattainmentareaswithinsuchanozonetransport  regioniftheAdministratordetermines(whentheAdministra  X torapprovesaplanorplanrevision)thatadditional x  reductionsofoxidesofnitrogenwouldnotproducenetozone @  airqualitybenefitsinsuchregion. (#(# TheAdministratorshall,intheAdministrator'sdeterminations,  x considerthestudyrequiredundersection185B.  @ Ѐ(2)(A)IftheAdministratordeterminesthatexcessreductions `  inemissionsofNOxwouldbeachievedunderparagraph(1),the (  Administratormaylimittheapplicationofparagraph(1)tothe   extentnecessarytoavoidachievingsuchexcessreductions. `  Ѐ(B)Forpurposesofthisparagraph,excessreductionsin (  emissionsofNOxareemissionreductionsforwhichtheAdminis H  tratordeterminesthatnetairqualitybenefitsaregreaterin   theabsenceofsuchreductions.Alternatively,forpurposesof   thisparagraph,excessreductionsinemissionsofNOxare,for H  0  (i)nonattainmentareasnotwithinanozonetransportregion h undersection184,emissionreductionsthatthe 0 Administratordetermineswouldnotcontributetoattainment  ofthenationalambientairqualitystandardforozonein h thearea,or0(#(# 0  (ii)nonattainmentareaswithinsuchozonetransportregion, P emissionreductionsthattheAdministratordetermineswould  notproducenetozoneairqualitybenefitsinsuchregion.(#(# Ѐ(3)Atanytimeafterthefinalreportundersection185Bis P submittedtoCongress,apersonmaypetitiontheAdministrator p foradeterminationunderparagraph(1)or(2)withrespectto 8 anynonattainmentareaoranyozonetransportregionunder  section184.TheAdministratorshallgrantordenysuchpetition p within6monthsafteritsfilingwiththeAdministrator. 8 1.3TheNOxRequirementsOXXX"X  !!   TheNOxrequirementsforNSRandRACTaredescribedinEPA's "f# proposedruletoimplementthe8hourozonestandard#"XXXOXU#(68FR #<$ 32810)OXXX"X .#"XXXOXV#SXXX"XԀWhereEPAgrantsanareawideexemption,theNOxRACTand j$% NSRrequirementsmaynotapply.#"XXXSX W#OXXX"XInaddition,areasgrantedaNOx @%& exemptionmaybeexemptfromcertainFederalrequirementsrelated &' toTitleVoperatingpermits,motorvehicleI/M,andgeneraland &( transportationconformity.#"XXXOXW#SXXX"XԀ 'j )   AsstatedinEPA'sinspectionandmaintenance(40CFR `)"+ 51.351(d))andconformityrules(40CFR#"XXXSXY#SXXX"XԀ93.119(f)(2)for (*", transportationrulesand40CFR#"XXXSXY#SXXX"XԀ93.152forgeneralrules), *#- certainNOxrequirementsdonotapplywhereEPAgrantedan +`$. areawideexemptionundersection182(f).Pursuantto40CFRPart ,(%/ 70.2(subparagraph(3)(i)underthe"majorsource"definition), H-%0 themajorsourcethresholdforfederaloperatingpermitprograms .&1 wouldbedefinedas100tonsperyearinareascoveredbyaNOx X exemption.#"XXXSXvZ#SXXX"XTheseexemptionsautomaticallyapply;i.e.,aState   doesnotneedtorequesttheapplicationorgrantingofthe  inspection/maintenanceorconformityexemptions.#"XXXSXآ\#OXXX"XԀ#"XXXOX]#ԀHowever,a  X Statemayrequestthatanexemptionapplyforlimitedpurposes.  . 1.4Section185BStudy     Undersection185B,theAdministrator,inconjunctionwith n  theNationalAcademyofSciences(NAS),conductedastudyonthe 6  roleofozoneprecursorsintroposphericozoneformation.The   NASreport,RethinkingtheOzoneProbleminUrbanandRegional n  AirPollution,wascompletedinDecember1991.Thefinalsection 6  185BstudyincorporatedthisNASreportalongwithanEPAreport V  addressingtheavailabilityandextentofNOxcontrols.The   section185BstudyexaminedtheroleofNO<"  x " ԀandVOCemissions,   theextenttowhichNO< V xV  Ԁreductionsmaycontributeorbecounter V  productivetoachievingattainmentindifferentnonattainment v areas,thesensitivityofozonetothecontrolofNO<z">x>z",the > availabilityandextentofcontrolsforNO<BxB,theroleofbiogenic  VOCemissions,andthebasicinformationrequiredforairquality v models.ThefinalstudywassubmittedtoCongressonJuly30, > 1993.Inmakingadeterminationundersection182(f)thatthe ^ NOxrequirementsdonotapply,ormaybelimited,theEPAmust & considerthesection185Bstudy.Thisdocument, Guidanceon  LimitingNitrogenOxidesRequirementsRelatedto8HourOzone ^ Implementation,includesconsiderationofthesection185B ~& study. F   1.5  ApplicationofSection182(f)Requirements ~   Section182(f)(1)providesthatthenewNOxrequirements f   shallnotapply8f!.!.!f!ԀiftheAdministratordeterminesthatanyoneof .!! thefollowingtestsismet: !" 0  (1)0` (#(#inanyarea,thenetairqualitybenefitsaregreater #.$ intheabsenceofNO<$2N$xN$$2Ԁreductionsfromthesources N$% concerned;%&` (#` (# 0  (2)0` (#(#innonattainmentareasnotwithinanozonetransport &N( region,additionalNO<'R n' xn' 'R Ԁreductionswouldnotcontribute n' ) toozoneattainmentinthearea;or6( *` (#` (# 0  (3)0` (#(#innonattainmentareaswithinanozonetransport )n", region,additionalNO<*r#*6#x*6#*r#Ԁreductionswouldnotproducenet *6#- ozoneairqualitybenefitsinthetransportregion.V+#.` (#` (#   Further,section182(f)(2)statesthattheapplicationof ,%0 thenewNOxrequirementsmaybelimitedtotheextentnecessary -V&1 toavoid excessreductionsofNOxasdeterminedbyapplying X testssimilartotests(1)(3)above.     Asdescribedlaterinthisdocument,the"netairquality  X benefits"testandthe"excessreductions"provisionmaybe x  appliedinanozonetransportregionoroutsidethetransport @  region;the"contributetoattainment"testmayonlybeapplied   outsideofanozonetransportregion;andthe"netozone  x benefits"testmayonlybeappliedwithinanozonetransport  @ region.Whereanyoneofthetestsismet(evenifanothertest `  failed),thesection182(f)NOxrequirementswouldnotapplyor, (  undertheexcessreductionsprovision,aportionofthese   requirementswouldnotapply. `    Asdiscussedinsection1.1above,EPAbelievesthesame H  conceptsinsection182(f)ofsubpart2shouldbeextendedto   areassubjecttosubpart1requirementsforpurposesofthe8   hourozonestandard.Thus,whilediscussioninthisdocument H  focusesonthelanguageinsection182(f),thereadershouldbe h awarethattheguidanceisintendedtoapplyequallytosubpart1 0 andsubpart2areas.  1.6  OrganizationofthisDocument 0   Chapter1,above,providesanintroductiontotheNOx  exemptionprovisions.Inchapter2,proceduralaspectsrelated  toarequestforaNOxexemptionarecovered.The"netair P qualitybenefits,""contributetoattainment,"and"netozone p benefits"testsaredescribedindetailinchapters35.The 8  excessreductionsprovisionisdiscussedinchapter6.  Chapters78providetechnicalinformationrelatedtomodeling p techniquesandemissionsanalysesthatmaybecarriedoutto 8 supportaNOxexemptionrequest.  X   @&CHAPTER2 X @ADMINISTRATIVEPROCEDURES  2.1  ProcessingwiththeStateImplementationPlan(SIP)Revision x    AStatemay,atanytime,demonstratetotheAdministrator   thatsomeoralloftheNOxrequirementslistedinsection1.2of  x thisdocumentshouldnotapply< | @ @ |.Forexample,aStatemaysubmit  @ ademonstrationalongwith,orasarevisionto,theSIPatthe `  timeNOxRACTrulesaredue.TheState'sNOxexemption (  demonstrationisnotrequiredtobeaSIPrevisionitself.   ̀  TheEPAwillapproveordisapprovetheState'sNOxexemption (  demonstrationwhentheAdministratorapprovesaplanorplan H  revision.TheEPAwillconsiderthesection185Breportandwill   baseitsdecisiononthedemonstrationandsupportinginformation   providedbytheState.Suchdemonstrationandinformationshould H  beinsufficientdetailforEPAtodeterminethattheexemption h requestisconsistentwiththeguidancecontainedinthis 0 document.TheEPAencouragestheStatestoconsultwiththe  appropriateEPARegionalOfficeduringthedevelopmentofthe h exemptionrequest.Thisisnecessarytoensurethatthe 0 documentationprovidedbytheStateislikelytobeapprovedand P thatanyrequiredrulescanbeadoptedinatimelymanner.  2.2  Petition P   Section182(f)(3)providesthataperson(includingaState) 8 maypetitiontheAdministratorforaNO<<x<Ԁexemptionatanytime  afterthefinalsection185BreportissubmittedtoCongress. p Thepetitionmaybemadewithrespecttoanynonattainmentarea 8 oranyozonetransportregion.TheEPAisrequiredtograntor X   denyasection182(f)petitionwithin6monthsafteritsfiling.  !!   SinceanindividualpetitionislikelytoaffecttheSIP "X# planningprocesswhichisprimarilyaStateresponsibility,EPA x# $ believesitisreasonabletorequirethepetitionertoprovidea @$% copyofthepetitionanddemonstrationtotheStateorStates %& whichhavejurisdictionoverthesourceorsourcescoveredbythe %x' petitionatthesametimeitissubmittedtotheAdministrator &@( (whereapetitionisbeingsubmittedbyapersonotherthanthe `' ) Stateitself).WhereadditionalStatesmaybeaffectedbythe (( * petition,theStatereceivingthepetitionshouldcoordinatewith (!+ theotherStatesasnecessary.Insomecasestheremaybe )`", multiplepetitionsforagivenarea.Inothercasesasingle *(#- petitionmayhavemultiStateimplications.TheEPAwillprovide H+#. theState(s)a3monthperiodtomakearecommendationtoEPA ,$/ regardingthepetition.This3monthperiodwillrun ,%0 concurrentlywiththe6monthreviewperiodrequiredunder -H&1 section182(f)(3).Thepetitionershouldsubmitthepetitionand X demonstrationtotheAdministratorthroughtheappropriateEPA   RegionalOffice.    TheEPAencouragesanypetitionertoconsultwiththeState x  airqualityagencyandtheappropriateEPARegionalOfficeduring @  thedevelopmentofanexemptionrequest.Thisisnecessaryto   ensurethatthedocumentationprovided(1)meetsEPAguidance,  x (2)doesnotconflictwithsimilaranalysesbytheState,and(3)  @ islikelytobeacceptedbytheStateandEPA.TheEPA's `  decisiontograntordenyapetitionwillincludeconsideration (  ofthesection185Breportandwillbebasedonthedemonstration   providedbythepetitioner,theState'srecommendation,andthe `  provisionsofsection182(f).Asnotedabove,thisdocumentsets (  forthEPA'spreliminaryinterpretationsofthesection182(f) H  provisionsandextendsthoseconceptstosubpart1areas.     TheEPAwillprovidenoticeofitsfinalactionona H  petitionandtherationaleforthatactioninalettertothe h petitioner.IfEPAdeniesapetition,thepetitionermay 0 supplementorrevisetheoriginalpetitionatalaterdate.If  EPAgrantsapetition,theNO<hxhԀrequirementsorportionsofthose h requirements,wouldnolongerapplytothosesourcesorareas,as 0 describedinEPA'sapprovalaction.SinceEPAapprovalofan P exemptionrequestwouldchangeSIPrequirements,EPAwould  conductnoticeandcommentrulemakingonthatrequest.  2.3  InterfacewiththeSIP p   WhereapetitionforanexemptionisgrantedbyEPApriorto  adoptionandsubmittaloftheState'srules,theStatemaysimply p choosenottosubmittheNOxrules.Ifapetitionisgranted 8 aftersubmittaloftheNOxrules,butpriortoEPAapproval,the X   StatemaychoosetowithdrawtherulesandprecludefurtherEPA  !! action.InacasewhereapetitionisgrantedafterEPAapproves !" oftheNO<""Xx"X"rules,theSIPwouldneedtobemodifiedthroughaSIP "X# revisiontorescindtheNO<#\x# xx# #\Ԁrulesprovidedsuchrescissionwould x# $ notinterferewithattainmentorreasonablefurtherprogress @$% [section110(l)]. %&   Followingapplicationofaphotochemicalgridmodelto &@( supportanattainmentdemonstration,Statesadoptacontrol `' ) strategythatprovidesforattainmentasexpeditiouslyas (( * practicable.Theselectionofacontrolstrategymayresultin (!+ revisionofthepreviouslyadoptedrules.InsomeinstancesNO<)")`"x)`")" )`", RACTandNSRrequirementsalreadyadoptedmayneedtobe *(#- supplementedwithadditionalormoreadvancedNO<+,$H+#xH+#+,$Ԁcontrolsin H+#. orderfortheareatoattaintheNAAQS. ,$/   Inothercases,anareainitiallyexemptedmaychoose,based -H&1 onthenewphotochemicalgridmodelingresults,toadoptcertain X NO<\ x \Ԁreductionrulesinordertoattainand/ormeetreasonable   furtherprogressrequirementsthroughNO<$ x$ Ԁsubstitution.Thearea  wouldberemovedfrom"exempt"statussinceNOxreductionswere  X subsequentlyfoundtobebeneficialintheirozoneattainment x  plan.Consequently,theareawouldhavetoadopttheNO<| $@ x@ | $ԀRACT @  andNSRrulesexcepttotheextentmodelingshowsthatthe   controlsbeyondthosechosenare"excessreductions"(chapter6)  x orarecounterproductivetothenetairquality(chapter3).  @ CreditforNO<D`x`DԀsubstitutionwouldbegrantedonlyifin `  accordancewiththeEPAguidance.Inanyevent,thesechanges (  mustbesubmittedasaSIPrevisionandmustprovidefor   attainmentasexpeditiouslyaspracticableandmeetreasonable `  furtherprogressrequirements. (    Alternatively,foranareathatadoptedtheNO<L  x L ԀRACTandNSR   rules(i.e.,notexempt),aStatemaychoosetorevisesomeor   allofthoserulestorequirelessNO< H xH  Ԁstationarysource H  controls.Thisactionwouldbebasedontheapplicationofa h photochemicalgridmodelshowingthatthesubjectNO<l0x0lԀcontrols 0 resultinexcessemissionreductions,asdeterminedusingthe  section182(f)testssetforthinthisdocument.Therevisions h mustbesubmittedasaSIPrevisionandtheSIPmustdemonstrate 0 attainmentasexpeditiouslyaspracticable. P   InareasthataregrantedaNOxexemptionwithrespectto  the8hourozonestandard,StatesremainfreetoadoptNO<PxP P restrictionsforotherreasons.Forexample,aStatemay p determinethatNOxreductionsareneededforpurposesofozone 8 maintenanceplanning,ozoneattainmentinseparatedownwind  nonattainmentareas,visibilityprotection,particulatematter p attainmentormaintenance,aciddeposition,orother 8 environmentalprotection.TheEPAcouldapprovecertainNOx X   restrictionsinaSIPrevisiondespitegrantinganexemption  !! request,solongastheNOxrestrictionswouldnotinterferewith !" meetinganyapplicablerequirementconcerningattainmentand "X# reasonablefurtherprogressoranyotherapplicablerequirement x# $ oftheCAA[seesection110(l)]. @$% OXXX"X  Manyoftheareasthatareviolatingeitherthe8hourozone %x' orPM2.5NAAQS,maybeviolatingbothoftheseNAAQS.Thus,in &N( manycases,StateswillhaveozoneandPM2.5nonattainmentareas |'$ ) withoverlappingboundaries.Requirementsforregionalhaze R( * applytoallareas.EachStateisresponsiblefordevelopingSIP ()!+ revisionstomeetalltherequirementsrelevanttoeach )", nonattainmentareaforeachpollutantaswellasdevelopinga *|#- regionalhazeplan.Insomecases,ozonecontrolmeasuresmay +R$. alsobeusefulforaPM2.5controlstrategyoraregionalhaze ,(%/ plan.Similarly,controlsforPM2.5mayleadtoreductionsin V-%0 ozoneorregionalhaze.Forexample,consideredinisolation,a X metropolitanareasozonestrategymightbebasedonadditional . VOCemissionsreductions;iftheareaneedsNOxreductionsfor   PM2.5attainment,however,anoptimalapproachmightincludea   morecomplexozonestrategyusingbothNOxandVOCreductions.  X WebelieveintegrationofozoneandPM2.5attainmentplanningwill  . reduceoverallcostsofmeetingmultipleairqualitygoals.An \  integratedassessmentoftheimpactcontrolshaveonozone, 2  secondaryfineparticles,andregionalhazeprovidessafeguards  toensureozonecontrolswillnotprecludeoptimalcontrolsfor   secondaryfineparticlesandvisibilityimpairment.#"XXXOX#OXXX"XԀTherefore, \  #"XXXOX#OXXX"XweencourageStatesconductingmodelinganalysesforozoneto 2  separatelyestimateeffectsofastrategyonthefollowing:mass `  associatedwithsulfates,nitrates,organiccarbon,elemental 6  carbon,andallotherspecies.#"XXXOX󦂥#OXXX"X    #"XXXOXܦ#< R R  2.4  Timing R    Section182(f)containsfewdetailsregardingthe : administrativeprocedureforactingonOXXX"XNOx#"XXXOX#Ԁexemptionrequests.  TheabsenceofspecificguidelinesbyCongressleavesEPAwith  discretiontoestablishreasonableprocedures,consistentwith H therequirementsoftheAdministrativeProcedureAct(APA). h   TheEPAbelievesthatsection182(f)setsuptwoseparate  proceduresbywhichtheAgencymayactonNOxexemptionrequests. h Section182(f)(1)and(2)directthatactiononNOxexemption 0 determinationrequestsshouldtakeplace"when[EPA]approvesa P planorplanrevision."Thislanguageappearstocontemplate  thatexemptionrequestssubmittedundertheseparagraphsare  limitedtoStates,sinceStatesaretheentitiesauthorizedunder P theActtosubmitplansorplanrevisions.Bycontrast,section p  182(f)(3)providesthat"person[s]"T v#  9      ׀maypetitionforaNOx 8!  determination"atanytime"aftertheozoneprecursorstudy "! requiredundersection185BoftheActisfinalized, andgives "p" EPAalimitof6monthsafterfilingtograntordenysuch #8# petitions.Althoughsection182(f)(3)references182(f)(1), X$$ therearecertainkeydifferencesinthelanguage.First,  %% individualsmaysubmitpetitionsunderparagraph(3)"atany %& time"(i.e.,evenwhenthereisnoplanrevisionfromtheState &X' pendingatEPA).Second,thespecifictimeframeforEPAaction x' ( establishedinparagraph(3)issubstantiallyshorterthanthe @( ) timeframeusuallyrequiredforStatestodevelopandforEPAto )!* takeactiononrevisionstoaSIP.Thesedifferencesstrongly )x"+ suggestthatCongressintendedtheprocessforactingonpersonal *@#, petitionstobedistinctandmoreexpeditiousfromtheplan X revisionprocessintendedunderparagraph(1).Thus,EPA   believesthatparagraph(3)'sreferencetoparagraph(1)  encompassesonlythesubstantivetestsinparagraph(1)[and,by  X extension,paragraph(2)],nottherequirementinparagraph(1) x  forEPAtograntexemptionsonlywhenactingonplanrevisions. @    TherequirementsoftheAPAapplywithrespecttothetype  x ofnoticewhichmustbeprovidedregardingEPAactiononNOx  @ exemptiondeterminations.Noticeandcommentrulemakingis `  requiredbytheAPAwhenEPAactioninvolvesnotjustfactual, (  butalsopolicyandlegalconsiderationsthatwillapplyasa   generalmatterand,thus,islegislativeinnature.Conversely, `  whenEPAactioncanproperlybedescribedaspartyspecificin (  nature,involvingconsiderationofprimarilyfactualevidence, H  noticeandcommentrulemakingisnotrequiredbytheAPA.In   suchacase,theEPAactioncouldconsistoftheissuanceofan   order[see5U.S.C.sections551(4)(7)and553].Giventhese H  requirementsoftheAPA,EPAbelievesthatundereitherofthe h proceduresestablishedinsection182(f),wheretherequestis 0 foranentireareatobeexemptedfromtheNOxrequirements,the  EPAmustgothroughnoticeandcommentrulemakingtograntor h denythepetition.Whereapetitionissubmittedforan 0 exemptiondeterminationrelatingtoanindividualsource(or P groupofsources)undersubsection182(f)(3),EPAmaygrantor  denythepetitionthroughanordertransmittedbylettertothe  affectedsource(orsources).TheEPAwillalsoprovidethe P publicwithnoticeintheFederalRegisterofthereceiptand p availabilityofthepetition,aswellasoftheEPA'sfinal 8 determination.    Section182(f)(3)requiresthatEPAgrantordenya 8 petition,whetherareawideorsourcespecific,within6months X   afteritsfiling.Wheretherulemakingprocessisfollowed,EPA  !! isawarethatthe6monthrequirementmaybeinfeasibleinsome !" cases.However,courtshaveruledthatevenininstances,such "X# astheonepresentedhere,whereaprescribedtimeframeforEPA x# $ actionapparentlyconflictswiththerequirementtoprovidethe @$% publicwithadequateopportunityfornoticeandcomment,the %& noticerequirementmustbemet.Therefore,EPAwillprocess %x' areawideexemptionrequestsbyrulemakingasexpeditiouslyas &@( practicable,withtheintentofmeetingthe6monthdeadline. `' )   Asnotedearlier,petitionssubmittedundersection (!+ 182(f)(3)arenotrequiredtobesubmittedasSIPrevisions. )`", Consequently,theStateisnotrequiredundertheActtoholda *(#- publichearinginordertopetitionforanareawideNOxexemption H+#. determination[seesection110(a)(1)and(2)].Forsimilar ,$/ reasons,iftheStateissubmittinganareawidepetitionunder ,%0 subsection182(f)(3),itisunnecessarytohavetheGovernor -H&1 submitthepetition.However,becauseoftheneedfor X consistencywiththerequirementsof40CFRpart58,EPAbelieves   that,particularlyincaseswheretheNOxexemptionrequest  (includingarequestforexemptionfromtheNOxrequirementsof  X theconformityrules)isbasedonmonitoringdata,ifsuchdata x  arecontainedinapetitionsubmittedbyapersonotherthanthe @  State,thepetitionshouldbecoordinatedwiththeStateair   agency.  x 2.5  Areaswitha1HourOzoneNOxExemption `  OXXX"X  ForareasthatwerepreviouslygrantedaNOxexemptionunder   the1hourozonestandardandrequestaNOxexemptionunderthe n  8hourozonestandard,EPAproposedonJune2,2003thatanew D  approvalactionisneeded.Thisisnecessarytoallowforpublic r  comment#"XXXOX#OXXX"X,toassureconsistencywiththeexemptionguidanceunder H  the8hourstandard,andtoaccountforanynewinformationthat   maypointtoadifferentconclusion.#"XXXOXU#ԀForexample,whilemany   areasreceiveda1hourOXXX"XNOx#"XXXOX#Ԁexemptioninthemid1990sonthe r basisofhavingairqualitymonitoringdatawhichmetthe1hour H ozonestandard,EPAwouldnotgrantaOXXX"XNOx#"XXXOX#Ԁexemptionforthe8 h hourstandardsimplyduetothat1hourozonedata.Furthermore, > severalareasthatinitiallyreceivedaNOxexemptiononthe  basisofphotochemicalgridmodelinghavesincerevokedthe v exemptionbasedonmorerecentstudiesshowingthenecessityof > OXXX"XNOx#"XXXOXa#ԀemissiondecreasesXXX"XԀinordertoreachattainment#"XXXX#.  ^ @&CHAPTER3 X @NETAIRQUALITYBENEFIT  3.1  Demonstration x    Thisdemonstrationappliestospecificsourcesinanozone   nonattainmentareaorinanozonetransportregion.Itmustshow  x thatNO< | @x @ |Ԁreductionsfromthesourcesseekingtheexemptionwould  @ becounterproductiveoverall,consideringthenetairquality `  benefits.Congressspecifiedinthis"test"forspecificsources (  ahigherhurdlethanintheothertestsforareawideexemptions:   thedemonstrationmustshowabeneficialimpactfromthe `  avoidanceoftheNOxcontrols.Theprocedureforthistestisto (  conductdispersionmodelinganalysesconsistentwithEPAguidance H  withandwithoutNOxreductionsatthesourcesconcerned.   3.2  Factors H    Unlikethetestsdescribedinchapters4and5,thistestis 0 notlimitedtoconsiderationofozoneimpacts.Instead,this  testisbasedonabroadersetofairqualityimpacts.Thereare h manyairqualityimpactsexplicitlyaddressedintheCAA,both 0 healthandwelfarerelated,thatmaybedirectlyorindirectly P relatedtoNOxemissions.Theseimpactsinclude,forexample,  ozoneandparticulatematterformation,visibilityimpairment,  aciddeposition,airtoxicsformation,andnitrogendepositionin P nutrientsensitiveareas. p   Duetothenumberandvarietyofimpacts,itisgenerally  impracticalorimpossibletocompareeffectsquantitativelyfrom p oneofthesefactorstothosefromanotherfactororamong 8 severalfactors.Forexample,thereisnoreadilyavailable X   scaletousetocompareozoneimpactswithaciddeposition  !! impactsand/orvisibilityimpacts.Thus,inordertodescribea !" methodfordeterminingthe"netairqualitybenefit,"a "X# distinctionmustbemaderegardingwhichofthemanyfactorscan x# $ andshouldbeanalyzed. @$%   Although"airqualityimpacts"couldpotentiallybedefined %x' inaverybroadmanner,EPAhasconcludedthattherelevantair &@( qualityimpactsmustberelateddirectlytogoals,standards,or `' ) mandatesthatareexplicitlyaddressedintheCAA.Thatis,the (( * testfornetairqualitybenefitsmustassurethatadecisionto (!+ grantanexemptionwouldnotinterferewiththeachievementof )`", thespecificprogramsorgoalsmandatedintheCAA.ThekeyCAA *(#- programsrelatedtoemissionsofNOxareattainmentand H+#. maintenanceoftheNationalAmbientAirQualityStandards(NAAQS) ,$/ fornitrogendioxide,ozone,andparticulatematterandtheacid ,%0 depositionprogram.TheprimaryNAAQSaresetbythe -H&1 Administratortoassureprotectionofthepublichealth.The X purposeoftheaciddepositionprogramistoreducethetotal   atmosphericloadingofsulfurdioxideandnitrogenoxides.    TheCAArequirestheprimaryNAAQStobeattainedas x  expeditiouslyaspracticableandincludesdeadlinesfor @  designationofareasattainmentstatus,ruleadoption,submittal   ofcontrolstrategies,andattainmentoftheprimaryNAAQS.To  x assurethataNOxexemptionwouldnotadverselyimpactanyCAA  @ requirements,theimpactsonattainmentoftheprimaryNAAQSneed `  tobeaprimaryconcerninthenetairqualitybenefittest. (  Therefore,EPAbelievesthenetairqualitybenefittestshould   focusonprotectionofthepublichealthandaddresstheeffect `  theexemptionwouldhaveonattainmentoftheprimaryNAAQSfor (  thecriteriapollutants. H    Secondarytests,asneeded,canextendtothe(qualitative   orquantitative)considerationofotherairqualityimpactsthat H  areexplicitlyrecognizedintheCAA.Thesecouldinclude,for h example,thewelfareeffectswhichEPAhasconsideredanddeemed 0 necessarytoprotectagainstinsettingsecondaryNAAQSforthe  criteriapollutants.Apetitionercouldalsoconsideranyother h airqualityeffectsthatareexplicitlyaddressedintheCAA 0 throughgoals,standardsormandates,forexample,acid P deposition,airtoxics,orvisibility.Whilewelfarerelated  impactsaddressimportantenvironmentalissues(forexample,  atmosphericdepositioninnutrientsensitiveareas),theCAA P generallydoesnotcontainthesamedetailedsetofrequirements p anddeadlinesasitdoesforthepublichealthrelatedNAAQS. 8 Further,EPAbelievesthatgrantingaNOxexemptionwouldnot  relieve,conflictwith,orotherwiseaffectasource'sobligation p orabilitytoachieveNOxreductionsconsistentwiththeacid 8 depositionrequirements.IncaseswhereNOxreductionsfroma X   utilitysubjecttosection407maybecounterproductivewith  !! respecttolocalairquality,EPAexpectstheStateandutility !" wouldbeabletousetheemissionaveragingprovisionsofsection "X# 407toachievetherequiredNOxreductionsatalocationwhere x# $ theyarenotcounterproductive.TheEPAbelievesthewelfare @$% relatedimpactsshouldbeasecondaryfactorinthenetair %& qualitybenefittest. %x'   Inallcases,themethodforconsiderationofthenet `' ) benefitsmustberelatedprimarilyto"airquality"sincesection (( * 182(f)specificallyrequiresadeterminationofthe"airquality" (!+ benefits.Thus,simplertests,suchasa"netemissions"test, )`", shouldnotberelieduponsincechangesinemissionsmaynotbe *(#- directlyrelatedtochangesinairquality.Ingeneral,air H+#. qualityimpactscanbebestdeterminedbyuseofairquality ,$/ dispersionmodels. h  ,%0  -H&1   Inordertouseairqualitydispersionmodelingwhenever X possibleandtoavoidconflictswithotherrequirementsofthe   CAA,themethodsdescribedbelowshouldbeusedtodeterminethe  netairqualitybenefitoveranappropriategeographicareawhich  X includestheozonenonattainmentareasencompassingornearbythe x  sourcesconcerned(seesection3.3).Thesemethodsincludea @  primaryconsiderationoftheprimaryNAAQSairqualitybenefits   andsecondaryconsiderationofotherairqualitybenefits.  x    A.0 ` OzoneNonattainmentAreas` ` (#` (#   Forareasthatarenonattainmentonlyforthe8hourozone   NAAQS,theeffectsofNOxreductionsonozoneconcentrations `  shouldbequantifiedwithcurrentlyavailableairquality (  modelingtechniquesconsistentwithEPAguidance(seechapter7). H  OXXX"XThenetairqualitybenefitshouldbebasedonacomparisonof   thegeographicareawhere8hourozoneconcentrationschangewith   andwithoutNOxreductionsfromthesourcesconcerned. d  Alternatively,thechangeinpopulationexposuretoozone : concentrationsmaybeused.#"XXXOX#ԀRXXX"XIfthemodelingshowsanet h disbenefitforozone#"XXXRX#,RXXX"XԀEPAcouldapprovetheNOx#"XXXRX'#RXXX"XԀexemption > request.#"XXXRX#   _(88c! !"^3"    ^32  B  .3  0 `   AreasNonattainmentforBothOzoneandNitrogenDioxide Z ^3݌ ` (#` (# Ќ    Forareasthatarenonattainmentforbothozoneandnitrogen B dioxide,NOxreductionsclearlyareneededtoprovidefor   attainmentofthenitrogendioxidestandard,whileeitherNOxor z VOCreductions(orboth)mightbestprovideforattainmentofthe B ozonestandard.InsuchcasesEPAwouldnotmakeafindingofa b  netairqualitybenefitsincetheCAArequirestheNAAQSfor * nitrogendioxidetobemetasexpeditiouslyaspracticable.  "^3"    ^3*2  C  .3  0 `   AreasNonattainmentforBothOzoneandParticulate !*! Matter^3*i݌J""` (#` (# Ќ  OXXX"X  Manyofthesamefactorsaffectingconcentrationsofozone #$ alsoaffectconcentrationsofsecondaryparticulatematter.For $X% example,similaritiesexistinsourcesofprecursorsforozone %.& andsecondaryparticulatematter.EmissionsofNOxmayleadto \&' formationofnitratesaswellasozone.Presenceofozoneitself 2'( maybeanimportantfactoraffectingsecondaryparticulate ( ) formation.Forexample,asozonebuildsup,hydroxyl(OH) (!* radicalsdoalsoasaresultofequilibriumreactionsbetween )\"+ ozone,waterandOHinthepresenceofsunlight.Hydroxyl(OH) *2#, radicalsareinstrumentalinoxidizinggasphaseSO2tosulfuric `+$- acid,whichf  g isf  g eventuallyf  g Ԁabsorbedbyliquidaerosoland 6,$. convertedtoparticulatesulfateinthepresenceofammonia.SO2  -%/ alsoreactswithozoneandhydrogenperoxide(abyproductof -&0 photochemistry),intheaqueousphase,toformparticulate X sulfate.HydroxylradicalsandNOarealsoprecursorsforgas . phasenitricacid,whichf  g f  g isf  g Ԁabsorbedbyliquidaerosoland,in   thepresenceofammonia,leadstoparticulatenitrate.#"XXXOXY#RXXX"X   #"XXXRX#OXXX"X  Strategiestoreduceozonecanalsoaffectformationof  . secondaryparticulatematterf  g f  g f  g .Reducing NOxemissionsdiminishes \  oneoftheprecursorsfornitricacid(i.e.,NO2whichresults 2  fromNO).Therefore,inthepresenceofsufficientammonia,  reducing NOxemissionscouldreduceparticulatenitrate   concentrations.Therearealsomoresubtleinterfacesbetween \  strategiestoreduceozoneandf  g toreducef  g secondaryparticulate 2  matter.Forexample,reducing NOxinthepresenceofsubstantial `  particulatesulfatesandlackofsufficientammoniacouldinsome 6  casesexacerbatetheparticulatesulfateproblem,orreducingSO2    inthepresenceofsubstantial NOxandammoniacouldinsome   casesexacerbatetheparticulatenitrateproblem.#"XXXOX#RXXX"X `  #"XXXRX#  Forareasthatarenonattainmentforbothozoneand d  particulatematter(PM10and/orPM2.5),amodelinganalysisis , neededthataddresseseachpollutantforwhichtheareais  nonattainment.RXXX"XԀ#"XXXRX#Thenetairqualitybenefitshouldbebasedona d comparisonofthegeographicareawhereconcentrationschange : withandwithoutNOxreductionsfromthesourcesconcerned. Z Alternatively,thechangeinpopulationexposureto " concentrationsmaybeused.OXXX"XԀ#"XXXOX#RXXX"XIfthemodelingshowsnet  disbenefitsforbothozoneand#"XXXRX#particulatematter(PM10and/or h PM2.5forboththeshortandlongtermstandards),RXXX"XԀEPAcould > approvetheNOx#"XXXRX#RXXX"XԀexemptionrequest.Ifthemodelingshowsa l disbenefitforonepollutantbutabenefitfortheother#"XXXRXO#,RXXX"XԀEPA B wouldnotmakeafindingofanetairqualitybenefitbecause(1)#"XXXRX #RXXX"X   thereisnotaclearnetairqualitybenefitsinceitis   difficulttocompareozonetoPMbenefits;(2)theCAArequires !l  theNAAQStobeattainedasexpeditiouslyaspracticable#"XXXRX#RXXX"XԀand "B! grantingtheexemptioncouldresultindelayedattainmentforone p#" pollutant;#"XXXRX#RXXX"XԀand(3)therearesecondarybenefitsfromNOx F$# emissionsreductionssuchasdecreasedacidrain.#"XXXRX#RXXX"XԀ#"XXXRXT# %$ "^3"  0  ^32  D  .3  0` (#(#  AreasNonattainmentforOzoneandCarbonMonoxide,Lead &b& orSulfurDioxide^3݌'* '` (#` (# Ќ    Forcarbonmonoxide,lead,andsulfurdioxide,EPAisnot )!) awareofanysignificantimpactsfromNOxemissions.Therefore, )"* thenetairqualitybenefitsdeterminationshouldbeprimarily *J#+ basedontheozonemodelinganalysisdescribedaboveforareas j+$, nonattainmentforonlyozone. 2,$- "^3"  0  ^3 2  E  .3  0` (#(#  SecondaryFactors^3  ݌-j&/` (#` (# Ќ    Asnotedabove,equalconsiderationofallNOximpactsis   generallyimpracticalinthisnetairqualitybenefittest  becauseofthelackofscalestocomparetheimpactsamongthe  X variousfactors.Nevertheless,additionalfactorsexplicitly x  addressedintheCAAsuchasthoselistedbelowmaybeconsidered @  inadditiontoanyinformationdevelopedfromtheNAAQSanalyses.   Considerationofthefactorsbelowisespeciallyimportantin  x caseswheretheanalysesontheNAAQSpollutantscannotclearly  @ determinethenetairqualitybenefit.Inanycase,EPAbelieves `  theamendedCAAplacesasubstantialburdenontheapplicantto (  provideaclearshowingthatNOxreductionswouldbe   counterproductiveoverall,consideringthenetairquality `  benefits.Additionalfactorstodeterminenetairquality (  benefitmayincludebutarenotlimitedto: H  0  1.0` (#(#Effectsassociatedwithlongtermexposurestoplants,   animals,andmaterials.H ` (#` (# 0  2.0` (#(#Visibilityimpairment,longtermandepisodicacid 0 deposition,airtoxics,anddepositionofnitrogenin  nutrientsensitivewatersheds.h` (#` (# 3.3  GeographicScope P   Incontrasttotheothersection182(f)tests,thenetair  qualitybenefittestisnotspecificallylimitedtoanozone P nonattainmentareaorozonetransportregionandmaybedirected p ataspecificsetofsources.Thus,averybroadgeographicarea 8 shouldbeconsidered.Theareamay,insomecases,extendbeyond  anozonenonattainmentareaorozonetransportregion.In p addition,theareamustnotbesosmallthatdownwindimpacts 8 fromNOxemissionsarenotfullyconsidered.Sufficientareais X   neededtoallowforcompletionandconsiderationofthevarious  !! chemicaltransformationsofNOxandinteractionwithother !" pollutants.Ataminimum,thegeographicareashouldincludethe "X# ozonenonattainmentarea(s)encompassingornearbythesources x# $ concerned.Forexample,petitioningsourceslocatedin @$% attainmentportionsoftheozonetransportregionshouldanalyze %& theirimpactonnearbynonattainmentareasandshouldconsider %x' otherfactors,suchasvisibilityimpactsthroughoutthe &@( surroundingarea. `' ) 3.4  Scenarios (!+   Section182(f)states,forthistest,thatEPAmust *(#- determinethatthenetairqualitybenefitsaregreaterin"the H+#. absenceofreductionsofoxidesofnitrogenfromthesources ,$/ concerned."Theprocedureforthistestistofirstproject ,%0 areawidebaselineemissionsthatmaybeexpectedattheozone -H&1 attainmentdeadline(seesections3.3and8.3).(Asdescribedin X section8.3,multiyearanalysesmayalsobeconducted.)Second,   theprojectedbaselineemissionsareheldconstant,exceptfor  thesubjectindividualsources.Then,theairqualityanalyses  X areconductedforthesetwoscenarios: x  0  1.0` (#(#theprojectedbaselineemissionswithoutNOxreductions   fromthesourcesconcernedand x` (#` (# 0  2.0` (#(#theprojectedbaselineemissionsincludingNOx `  reductionsatallemissionsourcessubjecttotheNOx (  requirements. ` (#` (#   Withrespecttonewmajorsources,thetwoscenariosshould (  takeintoaccountapplicationofthesection182(f)NSR H  requirementsasdescribedinsection8.5.   3.5  Sources H    Forthisnetairqualitybenefittest,theCAArefersto 0 "reductionsofoxidesofnitrogenfromthesourcesconcerned."  Forpurposesofthisanalysis,"thesourcesconcerned"are h definedasthesourcesthatwouldbeexemptedfromNOx 0 requirementsbythepetitionorStaterequest.Thesources P concernedmaybeidentifiedinanyofthefollowingways:(1)  specificindividualsources,(2)oneormoresourcecategories,  or(3)ageographicareacontainingagroupofsources.As P describedinsection3.4,thesourcesconcernedmustbeanalyzed p togetherwithothersourcesinthearea;theseotherNOxsources 8 shouldtakeintoaccountapplicationofanyNOxrequirements(as  partoftheareawidebaselineconditionsexpectedatthe p attainmentdeadlineyear)whicharenotthesubjectofthe 8 exemptionrequest.  X   @&CHAPTER4 X @LLCONTRIBUTETOATTAINMENT  4.1  Demonstration x    Thisdemonstrationappliesonlytoozonenonattainmentareas   thatarenotwithinanozonetransportregion.Thedemonstration  x mustshowthatadditionalNOxreductionswouldnotcontributeto  @ ozoneattainmentinthearea.TheeffectsofsubstantialNOx `  reductionsonozoneconcentrationsshouldbequantifiedwith (  currentlyavailableairqualitymodelingtechniquesconsistent   withEPAguidance(seechapter7).OXXX"XԀ#"XXXOX}## `    TheprocedureforthistestisOXXX"Xtoutilizeaphotochemical V  gridmodel(seechapter7)toestimatefutureozonedesignvalues ,  underconditionsthatmaybeexpectedwithintheattainment   deadlineperiodconsideringthreeemissionreductionscenarios   (seechapter8)#"XXXOX$#OXXX"X:(1)substantialVOCreductions;(2)substantial#"XXXOX{%# V NOxreductions;and(3)boththeVOCandNOxreductions.Ifeach , predicted8hourozonedesignvalueconcentrationunderscenario L (1)islessthanorequaltothatfromscenarios(2)and(3),  thenthetestispassedandtheNOxrequirementswouldnotapply.    IncertainozonenonattainmentareasitispossiblethatNOx l emissionreductionsmayhelptoreduceozoneconcentrationsunder 4 somemeteorologicalconditionsbutnotunderothers.Thephrase  "wouldnotcontributetoattainment"couldbeinterpretedtomean l thatNOxemissionreductionswouldnothelpreduce(1)any 4 areawide8hourozoneconcentration,(2)themajorityofareawide T 8hourozoneconcentrations,or(3)themostsevereareawide8  hourozoneconcentration.TheEPAbelievesthatthe"majority"  optionisnotappropriatesincethisistheonlyoneofthe  T  section182(f)testswhichisnotkeyedtonetbenefits. t!! Furthermore,(1)anareamayneedtodemonstrateattainmentunder <"" multiplemeteorologicalconditions,(2)generallyasmallnumber ## ofepisodeswillbemodeledand(3)theNAAQSisbasedon #t$ multipleareawideconcentrationsratherthanasinglelocations, $<% mostseverevalue.Fortheabovereasons,EPAbelievesthis \%& determinationshouldbebasedonall8hourozonepredicted $&' designvalues. &( 4.2  GeographicScope |($!*   ThisdemonstrationfocusesonattainmentoftheozoneNAAQS  *", "inthearea."TheEPAinterpretsthistomeaninthe *|#- nonattainmentarea.Incontrasttotheprovisionfortransport +D$. regions,whichislikelytoconsiderseveralattainmentand d, %/ nonattainmentareasinthesection182(f)analysis,this ,-%0 demonstrationislimitedtoconsiderationoftheeffectsina -&1 singlenonattainmentareaduetoNO<<XxX<Ԁemissionsreductionsfrom X sourcesinthesamenonattainmentarea.     Wherethedemonstrationincludesphotochemicalgrid  X modeling,EPAencouragesStates/petitionerstoinclude x  considerationoftheentiremodelingdomainsincetheeffectsof @  anattainmentstrategymayextendbeyondthedesignated   nonattainmentarea.Statesshouldconsidersuchimpactssince  x theyareultimatelyresponsibleforachievingattainmentinall  @ portionsoftheirStateandforensuringthatemissions `  originatingintheirStatedonotcontributesignificantlyto (  nonattainmentin,orinterferewithmaintenanceby,anyother   State. `    However,EPAbelievesNOxexemptionsundersection182(f)of H  theCAAandinterstatetransportofemissionsundersection   110(a)(2)(D)oftheActmustbeconsideredindependently.The   EPAhasseparateauthorityundersection110(a)(2)(D)torequire H  aStatetoreduceemissionsfromstationaryand/ormobilesources h wherethereisevidenceshowingthatsuchemissionswould 0 contributesignificantlytononattainmentorinterferewith  maintenanceinotherStates.Insomecases,then,EPAmaygrant h anexemptionfromcertainNOxrequirementsand,inaseparate 0 action,requireNOxemissiondecreasesundersection P 110(a)(2)(D).  4.30  ApplicabilitytoAreasMonitoringAttainmentP(#(#   Insomecases,anozonenonattainmentareamightattainthe 8 ozonestandard,asdemonstratedby3consecutiveyearsof  adequatemonitoringdata,withouthavingimplementedthesection p 182(f)NOxprovisionsoverthat3yearperiod.WheretheNOx 8 requirementswerenotimplementedoverthat3yearperiod,itis X   clearthatthesection182(f)languageismetsince"additional  !! reductionsofoxidesofnitrogenwouldnotcontributeto !" attainment."Thatis,sinceattainmenthasalreadyoccurred, "X# additionalNOxreductionscouldnotimprovethearea'sattainment x# $ statusand,therefore,thesectionNOxexemptioncouldbe @$% approved. %&   TheEPA'sapprovaloftheexemption,ifwarranted,wouldbe &@( grantedonacontingentbasis(i.e.,theexemptionwouldlastfor `' ) onlyaslongasthearea'smonitoringdatacontinueto (( * demonstrateattainment).TheStatemustcontinuetooperatean (!+ appropriateairqualitymonitoringnetwork,inaccordancewith40 )`", CFRpart58,toverifytheattainmentstatusofthearea.The *(#- airqualitydatareliedonfortheabovedeterminationsmustbe H+#. consistentwith40CFRpart58requirementsandotherrelevant ,$/ EPAguidance.IfitissubsequentlydeterminedbyEPAthatthe ,%0 areahasviolatedthestandard,EPAwouldconductnoticeand -H&1 commentrulemakingtoremovetheNOxexemption. X       @&CHAPTER5 X @ NETOZONEAIRQUALITYBENEFIT  5.1  Demonstration x    ThisdemonstrationappliesinanOzoneTransportRegion.It   mustshowthatadditionalNO<  xx x Ԁreductionswouldnotproducenet  x ozonebenefitsinthetransportregion.Inthistestthenet  @ benefitmustbedemonstratedonaregionwidebasis.TheEPA `  believesthistestshouldincludesallportionsofanOzone (  TransportRegioninwhichimpactsfromNOxemissionsfromthe   areaseekingtheexemptioncanbedeterminedbythephotochemical `  gridmodel. (    TheprocedureforthistestisOXXX"Xtoutilizeaphotochemical   gridmodel(seechapter7)toestimatefutureozonedesignvalues   underconditionsthatmaybeexpectedwithintheattainment d  deadlineperiodconsideringthreeemissionreductionscenarios : (seechapter8)#"XXXOXGA#OXXX"X:(1)substantialVOCreductions;(2)substantial#"XXXOXB# h NOxreductions;and(3)boththeVOCandNOxreductions.Thenet > ozonebenefitmaybedeterminedbycomparingtheozone  concentrationsmodeledinscenario(1)withresultsmodeledfrom v scenarios(2)and(3).OXXX"XThenetozonebenefitshouldbebasedon > acomparisonofthenetgeographicareawhere8hourozone l concentrationschangewithandwithoutNOxreductionsfromthe B sourcesconcerned.Alternatively,thenetchangeinpopulation  exposuretoozoneconcentrationsmaybeused.#"XXXOXdD#ԀRXXX"XIfthemodeling  showsanetdisbenefitforozone#"XXXRXF#OXXX"X,#"XXXOXF#RXXX"XԀEPAcouldapprovetheNOx#"XXXRXF#RXXX"X l exemptionrequest.#"XXXRX9G#ԀAsdescribedinchapter8,multiyear B analysesmayalsobeconducted. p 5.2  Factors !    TheozoneNAAQSissetat0.08partspermillion(ppm).In "8" defining"netozonebenefit,"however,EPArecognizesthat X## variousformsofexpressioncouldbeconsideredwithrespectto  $$ ozoneimpacts.However,ozoneconcentrationswithdifferent $% averagingperiodsandvaluescannotreadilybecomparedtoeach %X& other.Forexample,itisdifficulttocompareasetof1hour x& ' ozonepeakconcentrationsabove0.12ppmagainstasetof8hour @'( ozonepeakconcentrationsabove0.08anddeterminewhichresults ( ) aremorebeneficial. (x!*   TheEPAbelievesitisreasonabletofocusthenetozone `*#, benefitstestonthe8hour0.08ppmozoneNAAQS,wherepossible (+#- forthefollowingreasons:(1)the0.08ppmozoneNAAQShasbeen +$. setbytheAdministratorasthelevelnecessarytoprotectthe ,`%/ mostsensitiveindividualsfromadversehealtheffectswithan -(&0 "adequatemarginofsafety;"(2)ozoneconcentrationswith X differentaveragingperiodsandvaluescannotreadilybecompared   toeachother,and(3)thepurposeoftheNOxrequirementsis  primarilytoattaintheozoneNAAQS.Therefore,theaveraging  X timetobeusedshouldbethe8hourdailymaximumozone x  concentrationandtheanalysisshouldfocusonvaluesabovethe @  0.08ppmNAAQSlevel.Specifically,thenetozonebenefitstest   shouldfocusonthetotalgeographicareaortotalpopulation  x exposedtoozoneconcentrationsabovethe0.08ppmNAAQSlevel.  @   Themodelresultsinsomecasesmightshowallscenariosto (  bebelowthe0.08ppmozoneNAAQSlevel.Insuchcasessome   mightarguethatthereisnoozonebenefitand,thus,theNOx `  requirementsshouldnotapply.TheEPAdoesnotagreewithsuch (  aninterpretationbecausetheCAAspecifies"netozone"rather H  than"ozoneattainment"forthistest.Insuchcases,the   analysisshouldexaminevaluesjustbelowtheNAAQSlevelsothat   acomparisoncanbemade. H  5.3  Attainment/UnclassifiedPortions 0   Thesection182(f)(1)(B)demonstrationexplicitlyrefersto h nonattainmentareaswithinanozonetransportregion.TheCAA 0 doesnotclearlystatewhetherornotportionsofozonetransport P regionsthatareattainment/unclassifiedcanmakethenetozone  benefitdemonstration<.Thesection182(f)(1)netairquality  benefittestisavailabletoanyarea;however,asnoted P previouslyitisahigherhurdle.Thus,whileaseverely p pollutedareamightbeabletodemonstratethatNO<t8x8tԀreductionsdo 8 notapplybecausethe"netozonebenefits"testissatisfied,the  CAAcouldbeinterpretedtorequireNO<pxpԀreductionsinthe p surroundingattainmentareabecausethatareacannotmeetthe 8 sametest.ItisunlikelythatCongressintendedsucharesult. X     AnalternativereadingoftheCAAcanbefoundthrough !" section184(b)(2).Thisprovisionstatesthattheattainment/ "X# unclassifiedportionsofthetransportregionmustmeet"the x# $ requirementswhichwouldbeapplicabletomajorstationary @$% sourcesiftheareawereclassifiedasamoderatenonattainment %& area."Thus,theCAAcouldbeinterpretedtoprovidethesame %x' section182(f)(1)(B)demonstrationprocessfortheseattainment/ &@( unclassifiedareas,sincetheyshouldbetreatedasmoderate `' ) nonattainmentareasforthepurposeofapplyingthesection (( * 182(f)requirementsandmoderatenonattainmentareasinthe (!+ transportregionareeligibletomeetthe"netozonebenefits" )`", test. *(#-   Evenwithoutthatlanguage,EPAwouldbeinclinedtoallow ,$/ anattainment/unclassifiedareainatransportregiontosatisfy ,%0 the"netozonebenefits"test.Itwouldbeabsurdand, -H&1 therefore,itisunlikelythatCongressintendedtoapplymore X stringentrequirementsintheattainment/unclassifiedportionsof   thetransportregionthanwouldapplytothemoreseverely  pollutedportions.Congressapparentlydidnotintendanylesser  X requirementstoapplyintheattainment/unclassifiedportionsof x  thetransportregion.TheEPAbelievesthatitisappropriateto @  extendthesection182(f)provisionbeyondtheboundariesofa   nonattainmentareaintoadjacentattainment/unclassifiedareas  x whicharepartofthesamesection182(f)demonstration.Thus,  @ whereaState/petitionerdemonstratesthatNOxreductionswould `  notproducenetozonebenefitsinthetransportregion,thenthe (  section182(f)NOxrequirementswouldnotapplytothosesources   orareasasdescribedinEPA'sapprovalaction.Sucha `  demonstrationmustincludeallportionsoftheozonetransport (  regioninwhichimpactsfromNOxemissionsfromtheareaseeking H  theexemptioncanbedeterminedbythephotochemicalgridmodel.      CHAPTER6 X `@ EXCESSEMISSIONSREDUCTIONS  6.1  General x    Section182(f)(2)providestheflexibilitytolimitthe   scopeoftheNOxrequirements.ApplicationoftheNOx  x requirementscanbelimitedtotheextentthatanyportionof  @ thosereductionsaredemonstratedtoresultin"excess `  reductions."Thetestsfordemonstratingexcessreductionsare (  generallythesameasinsection182(f)(1):netairquality   benefit,contributetoattainmentandnetozonebenefit. `  However,inthiscase,thedemonstrationmustshowthataportion (  oftheotherwiserequiredNOxreductionsareeither H  counterproductivetothenetairquality,donotcontributeto   attainment,ordonotprovideanetozonebenefit[dependingon   thesection182(f)testapplied]. H    Asdescribedbelow,forthecontributetoattainmentornet 0 ozonetests,theexcessreductionstestmustshowthatcertain  NOxreductionsareinexcessofthereductionsspecifiedin h eitherthe8hourozoneattainmentdemonstrationcontainedinthe 0 approvedSIPorthe8hourozoneattainmentdemonstrationadopted P bytheStatesubmittedtoEPAforapproval.Theexcessemission  reductionsmaybedescribed,forexample,as(1)anareawide  acrosstheboardtonnagereduction;(2)emissionsattributedto P specificsources;or(3)emissionsfromageographicportionof p thenonattainmentortransportarea. 8 6.20  Demonstrationp(#(#   The"contributetoattainment"and"netozonebenefit"tests X   describedinchapters4and5requireanareawideorregional  !! analysis.Insuchareawide/regionalanalyses,NOxemission !" reductionsatalargenumberofsourcesareconsidered.These "X# analysesareappropriatetodetermineinadirectionalmanner x# $ whetherornotNOxreductionsareexpectedtobebeneficialwith @$% respecttotheairqualityinthearea/region.Theanalyses %& describedinchapters4and5maybelessprecisethanan %x' attainmentdemonstrationrequiredundersection182(c). &@(   TheEPAbelievesthattheexcessreductionsprovision (( * requiresamorepreciseanalysis;specificallyananalysiswhich (!+ isbasedontheattainmentdemonstration.Thatis,theexcess )`", reductionsprovisionmustbemorethanadirectionalfindingon *(#- anareawidebasis.Undertheexcessreductionsprovision,an H+#. analysisisneededtoshowthataspecificportionofthetotal ,$/ areawideNOxemissionsisnotbeneficialunderoneofthethree ,%0 tests.Thus,individualorgroupsofsourcesmaypetitionto -H&1 showthat,whileNOxreductionsmaybebeneficialdirectionally X inthearea,NOxreductionsfromtheirspecificsourcesarenot   beneficialand,thus,shouldbeexemptfromtheNOxrequirements.  ̀  Withoutprovidingsomeconstraintsinthisguidance x  document,theexcessreductionsprovisionscouldunderminethe @  section182(f)requirements,sinceeachindividualemission   sourcecouldtheoreticallypetitionforanexemptionwiththe  x argumentthattheirsmallcontributiontotheoverallozone  @ problemisinconsequential.Suchapetitionmightbeconsidered `  consistentwiththeanalysesrequiredinchapters4and5,since (  anexemptionmaybegrantedwherethemodeledNOxreductionsshow   noimpactonozoneconcentrations.Certainly,ifEPAallowed `  verysmallamountsofNOxreductionstobemodeledindividually, (  thisinterpretationcouldcreateafalseimpressionthat H  individuallythesourcesdonotaffectattainmentwhen,infact,   theaggregateofthesourcesdoes.Congresswouldnothave   intended,andthereforeEPAdoesnotaccepttheargument,that H  theowner/operatorofonecaroronesmallboilercanbeexcused h fromtheCAArequirementsbecausetheiremissions,viewedalone, 0 aresmall.Consideredtogetherwithothersmallcontributions,  theemissionsmaybeimportanttoattainment.Thatis,emissions h fromonecaroronecommercialboilerwouldnotchangethe 0 areawideozoneconcentration,yettogetherwithothercarsor P boilers,theymaybecriticaltothearea'sattainmentstrategy.  Furthermore,asdescribedelsewhereinthisdocument,ozoneair  qualitymodelsshouldnotbeappliedsolelytodeterminethe P incrementaleffectofsmallsourcesassuchemissionscouldbe p lostinthenoiseoftheairqualitymodelandemissions 8 inventoryuncertaintieswhenconsideredalone.    Fortheabovereasons,EPAhasdeterminedthattheexcess 8 reductionsdemonstrationforthe"contributetoattainment"or X   "netozonebenefits"testsmustbetiedtothearea'sSIP  !! attainmentdemonstration.Thus,thistestmustshowthatthe !" excessreductionsarereductionsinexcessofthosespecifiedin "X# theareasattainmentdemonstrationandeithercontainedinthe x# $ approvedSIPorasadoptedbytheStateandsubmittedtoEPAfor @$% approval.Thistietotheattainmentdemonstrationassuresthat %& anexcessreductionspetitionwouldnotarbitrarilybebasedon %x' smallemissionsandwouldnotunderminetheState'scontrol &@( strategy. `' )   Incontrast,the"netairqualitybenefit"testdiscussedin (!+ chapter3isintendedtoaddressanindividualorsmallnumberof )`", sourcesandalreadyhasanadequateconstraint.Thenetair *(#- qualitybenefittestrequiresashowingthatNOxreductions H+#. specificallyfromthesourcesconcernedarecounterproductive. ,$/ Thenetairqualitybenefittestimposesahigherhurdlethanthe ,%0 othertwotestsandEPAbelievesthishigherhurdleisadequate -H&1 forpurposesoftheexcessemissionstestaswell.  X @&CHAPTER7 X @xx!MODELINGTECHNIQUES  7.10  PhotochemicalGridModelingx (#(#   Asdescribedinchapters36,photochemicalgridmodelingis   generallyneededtodocumentcaseswhereNOxreductionsare  x counterproductivetonetairquality(chapter3),donot  @ contributetoattainment(chapter4),donotshowanetozone `  benefit(chapter5),orincludeexcessreductions(chapter6). (  OXXX"XTheEPAscurrentmodelingguidelineiscontainedin40CFRpart   51,appendixW.#"XXXOX5#OXXX"XInaddition,proceduresformodelingozoneand n  particulatematterarecontainedinEPAguidancef  g #"XXXOX#OXXX"Xf  g Ԁ#"XXXOX󦶁#OXXX"XpostedonEPAs D  website4U >O  5  (http://www.epa.gov/ttn/scram/).f  g 6]>Oqatio  7pl#"XXXOX#OXXX"XԀ#"XXXOXZ#OXXX"XTheEPAhasdraft r  modelingguidanceforuseinattainmentdemonstrationsforthe H  ozoneandPM2.5NAAQS.#"XXXOX󦞃#OXXX"XԀ#"XXXOXv#OXXX"X     ItisimportanttonotethatEPAbelievesthatphotochemical r gridmodelsarenotsufficienttoassessincrementalchangesto H areawideozoneconcentrationsfromemissionsreductionsata v singleorgroupofsmallsources.Emissionchangesshouldamount L tosomesignificantfractionofbaseemissionsbeforemodeling " resultscanbeinterpretedwithsufficientconfidencethatthe  resultsarenotlostinthenoiseofthemodelandtheinput v data.TheEPAhasreservationswithrespecttomodelingNOx L reductionsatasinglesourceorgroupofsourcesunlessthe z" modelingincludesatleast10%ofthedomainwideemissions. P Thus,thisexemptionanalysisisappropriateforgroupsoflarge & emittersorforconsiderationofentiresourcecategories,rather  thanemissionreductionsatasingleorgroupofsmallsources. z However,EPAwillconsideronacasebycasebasisananalysis  P thatconsiderslessthana10%changeinthedomainwide ~!&  emissions.Insuchcases,theanalysisofasmallportionofthe T"! emissionswouldshowonlyasmalldifferenceinozone *#" concentration,ifany,betweenthewithNOxandwithoutNOx $# scenarios,and,therefore,considerationofsecondaryfactors $~$ (describedbelow)isparticularlyimportantinordertoshowa %T% netairqualitybenefit. &*& #"XXXOX󦹄#OXXX"X#"XXXOXȋ#  TheEPAinvestigatedthefeasibilityandacceptabilityof .( ( applyingrelativelyinexpensivescreeningtechniquestoevaluate (!) ifNOxcontrolmeasuresarelikelytobebeneficialwithrespect )f"* toattainmentoftheozoneNAAQS(LangstaffandScheffe,1991). *.#+ However,EPAdeterminedthat,asatechnicalmatter, N+#, photochemicalgridmodelingistheonlyreliabletooltojustify ,$- anareawideexemptionfromtheNOxrequirements.TheEPA's ,%. relianceonphotochemicalgridmodelsissupportedbythe -N&/ findingsoftheNASontroposphericozone(December1991).The X NASreportconcludedthatthreedimensionalorgridbasedozone   airqualitymodelsarethebestavailablemodelsforrepresenting  thechemicalandphysicalprocessesofozoneformation.Less  X sophisticatedmodels,suchasEKMA,lackthedetailed x  treatment/considerationofphysicalorientationofNOxsources @  anddispersionoftheirplumes.Further,sincetrajectorymodels   onlyaddressalimitednumberoftrajectories,theycannotassess  x whetherNOxcontrolcontributestoattainmentatalllocationsin  @ anozonenonattainmentarea.Therefore,suchmodelsare `  insufficientandnotacceptableforaNOxexemption (  demonstration.    7.20  RegionalModeling( (#(#   Inanozonetransportregion,thenetozonebenefitstest   shouldbemetbyuseofregionalmodeling.Regionalmodelingis   neededsincethesection182(f)languageexplicitlyreferstonet H  ozonebenefits"insuchregion."Forpurposesofthisdocument, h regionwideorregionalmodelingincludesallportionsofthe 0 ozonetransportregioninwhichimpactsfromNOxemissionsfrom  theareaseekingtheexemptioncanbedeterminedbythe h photochemicalgridmodel. 0   P @&CHAPTER8 X @!EMISSIONSANALYSIS  8.1  General x    Asdescribedinchapters36,photochemicalgridmodelingis   neededtodocumentcaseswhereNOxreductionsare  x counterproductivetonetairquality(chapter3),donot  @ contributetoattainment(chapter4),donotshowanetozone `  benefit(chapter5),orincludeexcessreductions(chapter6). (  Applicationofthesemodelsrequirestheuseofarepresentative   emissionsinventory.OXXX"XTheEPAsmodelingguidance(chapter7) `  includesdiscussiononhowtodevelopappropriateemissions 6  estimatesforuseintheselectedairqualitymodel.Topics d  includeuseofavailableinventoryestimates,qualityassurance, :  applicationofemissionsmodelsandestimatingfutureemissions.   Thischapterdescribesadditionalemissioninventoryrequirements   forthevariousNOxexemptiondemonstrations#"XXXOX#. d 8.2  YearstoAnalyze Z   Ingeneral,thepurposeoftheNOxrequirementsisrelated  toattainmentoftheozonestandard.ThissuggeststhataNOx Z exemptiondemonstrationshouldfocuswithintheperiodozone z" attainmentisrequired(i.e.,thethreeyearperiodusedto B determineattainment).Further,manyareasarelikelytodevelop   modelinganalyseswhichdemonstrateattainmentwithinthe z attainmentdeadlineperiod.Inmanycases,theemissions B inventory,meteorologicaldata,episodedayselections,and b  controlstrategieswhichsupporttheattainmentdemonstration * couldalsobeusedtosupportaNOxexemptionanalysis.As  describedinsection8.4,theNOxexemptiondemonstrationshould  b  beconsistentwithassumptionscontainedintheSIP.Considering !*! thesepoints,EPAbelievesthattheNOxexemptiondemonstrations J"" should,ataminimum,reflectconditionsexpectedwithinthe ## threeyearperiodduringwhichthesubjectareaisrequiredto #$ attaintheozonestandard. $J%   Thus,baseyearemissionswouldbeprojectedtotheperiod 2&' reflectingtheattainmentdeadlineandwouldincludegrowthin &( VOCandNOxemissionsaswellasCAAmandatedemission 'j ) reductions.SpecificemissionscenarioswithandwithoutNOx (2!* reductionswouldbebuiltuponthisprojectedemissionsbaseline R)!+ asdescribedelsewhereinthisdocument.Inaddition,as *", describedlaterinthischapter,multiyearanalysesmayalsobe *#- conducted. +R$.   Inanozonetransportregion,aNOxexemptiondemonstration :-%0 wouldlikelycoveranareawhichincludesozonenonattainment .&1 areasofmorethanoneclassification,andthusmorethanone X attainmentdeadline.Forexample,ametropolitanareamayhavea   higherclassificationthananearbyruralnonattainmentarea.  Fortheseareas,itispossiblethatNOxreductionsmaybe  X beneficialtoattainmentintheneartermwithrespecttothe x  ruralnonattainmentarea(andlesserclassificationdeadline) @  but,atthesametimeorinalongertimeframe,NOxreductions   mightbeshowntobenotbeneficialwhenconsideringtheareaas  x awhole(sinceNOxreductionsaregenerallyexpectedtobemore  @ beneficialinruralareas).Inordertodeterminewhetherthe `  NOxreductionrequirementsshouldapply,EPAbelievesthat,ata (  minimum,theNOxexemptiondemonstrationshouldreflect   conditionsexpectedatthelatestattainmentdeadlineperiodfor `  theareaasawhole. (    Alternatively,theState/petitionermayincludeamultiyear   analysisinitsNOxexemptiondemonstration.Thisisappropriate   forareasdemonstratingeitheranetairqualitybenefitoranet H  ozonebenefit.Inthesedemonstrations,theanalysismayinclude h periodicassessmentsoftheeffectsofNOxreductionsand 0 integratethoseeffectstoarriveatafindingonwhetherornot  NOxreductionsarebeneficial.Forexample,anareamaydevelop h geographicareaexposureanalysesforeachyearorforevery 0 thirdyearuptotheattainmentyearandassesstheoverall P impactofNOxreductionsfromthatinformation.  8.3  ScenariostoCompare P   Forthecontributetoattainmentandnetozonebenefit 8 tests,theprojectedemissionsshould,ataminimum,consider  threescenarioswhichvaryemissionreductionsfromanthropogenic p sources:(1)substantialVOCreductions;(2)similarNOx 8 reductions;and(3)boththeVOCandNOxreductions.Total X   emissionstomodelincludebothanthropogenicandbiogenic  !! emissions. !"   Incontrasttothenetairqualitydemonstration(chapter3) x# $ whichfocusesonthescenario"intheabsenceofreductionsof @$% oxidesofnitrogenfromthesourcesconcerned,"thecontributeto %& attainmentandnetozonebenefitdemonstrationsconcernan %x' unspecified"additionalreductions"ofNOx.Thus,whilethenet &@( airqualitybenefittestmustfocusonNOxreductionsspecificto `' ) theexemptionrequest,theotherdemonstrationsmaymorebroadly (( * considerNOxreductions,includingreductionsthatemploy (!+ advancedcontroltechnology(i.e.,beyondRACT).Theapplication )`", oftheVOCandNOxreductionsshouldbeassourcecategory *(#- specificaspossible,ratherthanacrosstheboard,inorderfor H+#. theresultstobemostuseful. ,$/   InthefirstscenariothedemonstrationshouldusetheVOC -H&1 reductionsneededtoattain,ifavailable.Alternatively,ifthe X attainmentdemonstrationhasnotbeencompleted,the   demonstrationmayusesomeothersubstantialVOCreduction.  Reductionsassociatedwithattainmentareappropriateforthe  X reasonsdescribedabove.Inanycase,theVOCreductionsshould x  besubstantialanddocumentedasreasonabletoexpectforthe @  areaduetotheCAArequirements.Forexample,a40%   anthropogenicVOCreductionareawidefromthe2002emission  x inventorymaybereasonabletoexpectforseriousareas,  @ consideringmotorvehicleemissioncontrols, `  inspection/maintenance,reasonablefurtherprogressandotherCAA (  requirements.     Inthesecondscenario,NOxreductionsshouldbemodeled (  withoutanyVOCreductionsabovetheattainmentyearbaseline. H  ThelevelofNOxreductionsshouldreflectthesamepercent   reductionofanthropogenicVOCemissionsinscenario(1)above.   ItisimportanttomodelthiscasesinceNOxreductions,instead H  ofadditionalVOCreductions,mayshowaclearerbenefit. h   Inthethirdscenario,asimilarlevelofNOxreductions  wouldbemodeledalongwiththelevelofVOCreductionschosen. h Thatis,ifa40%VOCreductionischoseninscenario(1),then 0 themodelforscenario(3)wouldsimulatea40%VOCreductionand P approximatelya40%NOxreduction.Itwouldbeinappropriateto  selectahighlevelofVOCreductionsandalowlevelofNOx  reductionssincethiscouldartificiallyfavorafindingthatNOx P reductionsarenotbeneficial;thetwolevelsshouldbesimilar. p Ѐ8.4  ConsistencywiththeSIP    AnyNOxexemptiondemonstrationmustincludeashowingthat 8 theexemptionrequestusesassumptionsthatareconsistentwith X   requirementsoftheSIPandtheCAA.Itispossiblethata  !! petitioncoulddemonstratethat,undersomecircumstances,NOx !" reductionsarenotneededtoattaintheozonestandard.However, "X# unlesstheStateactuallyadoptsthoseparticularcircumstances x# $ intoitsSIP,thereisnoassurancethatthepetition'sanalysis @$% isvalid.Thatis,iftheassumptionscontainedinthe %& petitioner'sdemonstrationarenotvalid,theconclusionsare %x' similarlynotvalidandEPAwouldnotapprovethepetition.The &@( NOxexemptionpetitionprocessshouldnotunderminetheState's `' ) implementationplan.Thepetitionshouldreflectmeasures (( * consistentwithmandatoryCAArequirements,federallyapproved (!+ SIPrequirements,andrecentSIPrevisionsadoptedbytheState )`", andsubmittedtoEPAforapproval.TheEPAencourages *(#- petitionerstocoordinatetheseanalyseswiththeappropriate H+#. State(s)astheyarebeingdeveloped. ,$/ 8.5  NewSourceReview -H&1 Ї  Thesection182(f)exemptionprovisionscenterontheeffect X onozoneconcentrationsduetoNOxemissionreductions.With   respecttoRACT,whichinvolvesemissionsreductionsfrom  existingsources,thisisaperfectfit.Inthecaseofnewor  X modifiedsources,however,otherfactorsshouldbeconsidered. x  Evenaftertheapplicationofonsitecontrolsappropriatefora @  majornewormodifiedsource,thesourcewill,consideredalone,   resultinmajorincreasesinNOxemissions.However,theNSR  x offsetprovisionswouldrequirethenewsourcetoobtainemission  @ reductionsfromothersourcessoasoffsetanyemissionsincrease `  associatedwiththenewsource. (    TotakeintoaccountthefullimpactoftheNSRprogram,the `  term"NOxreductions"mustbecarefullyinterpreted.When (  consideringtheairqualityimpactsinchapters36ofthis H  document"withNOxreductions"orwith"substantialNOx   reductions,"theanalysisshouldreflectazeroemissions   increasefromstationarysourcesduetotheNSRoffset H  requirement;whenconsideringthe"without"NOxreductions h scenarios,theanalysisshouldincludeNOxemissionincreasesdue 0 tonewormodifiedstationarysourcesofNOx,manyofwhichwould  besubjecttothebestavailablecontroltechnologyrequirement h throughthepreventionofsignificantdeteriorationprogram,but 0 nottooffsets.