WPC :-q2u*~ֲ~U:9) ,pCK 0Ah ^GRG)2ζ)n="[i;:E\CyG#ku(Yka>.(t+e5S݉tg(vwnV0?"ģAŵrHZı!c y%#:1_ԱcP[cSow" NڪI m+&9O)#vOW#˚n x=Ba+ԄVޮ{)5 0t茗 Dz[Ȁ ͨZzD?H_AA+.]k eyP4o5mARdǏz=F]AJhJcO5z1u=YxiazXE_W xw.pq${ 9h H$gӸeR drlD2ֹ Q~vWzL7kӱn'3%‡?=]#UN %% 0:+ ^ e wq 4u   m $ U4 0V e _ Ni i 0~k 0D -  8 U@- 0NmmU@\\\\\\\\\\\ BHP LaserJet 6Pd,,,,,d,0(9 Z6Times New Roman RegularX($USUS.,Դ* f*PtePT3|xU   )USUS.,  _UXX.fVC:\WINDOWS\TEMP\calc_emiss_AQPS-01-0552.wpdfC:\WINDOWS\TEMP\calc_emiss_AQPS-01-0552.wpd/  #XXXU=#)Q}AZGill Sans (.3$ !USUS.,   (.(3($ !USUS.,      0  (#$  0    ($USUS.,    2    _XXXXXEPAMethod18hasthepotentialtocometheclosesttoestimatingactualmassofallof  theorganicsthatareinthegasstream;however,itisnotoftenpossibletoidentifyallthespecies  presentandtocalibrateforeachone.#XXXXXXe# mailto:deroeck.dan@epa.gov.(I Z(Times New Roman (O$  ($USUS.,    1    _XXXXXAsyoupointout,theguidancecontainedinChapterAofEPAsDraftNSRWorkshop  Manual(October1990)providesthatsignificantemissionsofNOxare basedonthesumofall  oxidesofnitrogen.(Footnotea,TableA4,pageA.20oftheManual.)Thishighlightsthefact  thatnotjusttheNO2componentofasourcesNOxemissionsistobeconsideredwhen t quantifyingtotalNOxemissions.FurtherguidancecontainedintheEPAreference(instack)test ` methodsandEPAguidancefordevelopingemissionfactorsandinventoriesindicatesthatthe L  totalmassistobecalculatedonthebasisofthemolecularweightofNO2.(hH  Z(Times New Roman   e  d !USUS.,  _ XXXXXXX X 'W8XXXdd8  @$June5,2001  Mr.D.EdwardSettle P  Manager,AirQuality @  _ThermoRetec_ԀCorporation 0  1726ColeBlvd.,Bldg.22,Suite150  p   Golden,CO804013213 `  DearMr.Settle: @    ThisisinresponsetoyourletterdatedFebruary1,2001,inwhichyourequested   clarificationofourguidanceforcalculatingactualorpotentialemissionsofcertainregulated  pollutantsfromanewsourceormodification.Yourspecificissuewaswhethertheemissionrate,  intonsperyear,shouldbecalculatedtorepresentthe endofpipereleaseoratheoretical  releaserateofareferencecompound.Youfurtherindicatedthattheregulatedpollutantsthatyou  wereconcernedaboutincludedtotalreducedsulfurcompounds,fluorides,volatileorganic  compounds(VOC),sulfurdioxide,andnitrogenoxides.Asfurtherexplainedbelow,ourgeneral p policyforcalculatingactualorpotentialemissionsfromnewandmodifiedstationarysourcesis ` tofollow,totheextentpossible,theEnvironmentalProtectionAgency(EPA)methodsand P proceduresfordevelopingemissionfactors/inventoriesandmeasuringsourcecompliance. @   InaletterdatedMarch1,1996,fromRobert_Kellam_,ActingDirector,Information  p TransferandProgramIntegrationDivision,toDonald_Gabrielson_,whichyoureferencedinyour ` letter,itwasstatedthat ifactualemissionsareusedasthebasisfordeterminingthepotentialto P emitforasource,thentheseemissionsshouldbemeasuredatthepointwheretheemissionsare @ released.Thisstatementwasintendedtoreflectourposition(statedabove)thatemission 0 calculationsshouldnormallybedoneinamannercompatiblewithproceduresfordeveloping   emissionfactors/inventoriesandmeasuringsourcecompliance.Thishelpstoensurethatany ! emissionlimitationestablishedforasourceforNewSourceReview(NSR)andtitleV "  applicabilitywillbecompatiblewiththeformatsbywhichemissionsarequantifiedfor #! inventoriesandsourcecompliance. $"   InthecaseofNOxemissions,forexample,theEPAguidancefordevelopingemission p&!$ factorsandfordeterminingsourcecomplianceindicatesthatNOxemissionsaretobecalculated `'"% onthebasisofthemolecularweightofNO2.SuchguidanceiscontainedintheEPAs P(#&  ProceduresforPreparingEmissionFactorDocuments,(EPA454/R95015,November1997) @)$' andisconsistentwiththereferencetestmethodscontainedin40_CFR_Ԁpart60AppendixAforthe 0*%(  measurementofoxidesofnitrogen.Eachoftherelevanttestmethods(withtheexceptionof  +p&) 'W 'e '  Method7E)directstheusertomeasure/calculatetheinstackemissionsofNOxasNO2. #  1      ׀ d    Fortheotherregulatedpollutantsthatyoulisted,withtheexceptionofVOC,calculation D oftheactualorpotentialemissionsforpurposesofNSRandtitleVapplicabilityshouldfollow 4  theEPAprinciplesfordevelopingemissionfactors,inventoriesandtestmethodsforthesubject $  pollutant.ForVOCemissions,however,itisrecognizedthattheEPAstestmethodsdonot   measurethepollutantmassexactlyoronlymeasureasubsetofthepollutantmass. #  2      ׀   Nevertheless,forthepurposesofbothNSRandtitleVapplicability,ourpolicyhasbeenthat   VOCemissionsshouldbecalculatedasthetotalmassof_VOCs_.Thatis,avalueforeachvolatile   organiccompoundknowntobeemittedshouldbecalculatedseparatelyandthesumofthe p  individualvaluesshouldbereportedastotal_VOCs_Ԁ(e.g.,20_tpy_Ԁoftolueneand26_tpy_Ԁofmethyl `  ethylketoneshouldbecalculatedseparatelyandthenreportedas46_tpy_ԀofVOC).Thisfollows P  ourguidanceinthedocumenttitled ProceduresforPreparingEmissionFactorDocuments, @  whereweindicatethatemissionfactorsfor_VOCs_Ԁshouldbereported intermsofactualweight 0  oftheemittedsubstance.ThoseorganicsubstanceswhicharespecificallyexcludedfromEPAs   definitionofVOCat40_CFR_Ԁ51.100(s),becausetheyhave negligiblephotochemical t reactivity,shouldnotbeincludedinthetotalVOCemissioncalculationforNSRandtitleV d applicability.Thedocumentalsoprovidesanexceptioninthecaseofunknownspeciesby T statingthatsuchemissionsshouldbecalculatedusingan educatedguessoramolecularweight D of44(forreportingaspropane).Wherenecessary,thisprocedureshouldbeusedtocalculate 4 emissionsofthosevolatileorganiccompoundsthatcannototherwisebequantified. $   ItistheEPAsintentthataconsistentapproachbetaken,whereverpossible,toquantify  andreportpollutantemissionsforitsvariousairprograms.Thus,themethodsdescribedabove  forquantifyingpollutantemissionswouldalsoapplytoourproceduresforsuchthingsasNSR  netting,emissiontradingandoffsets,aswellasforotherSIPrelatedprogramsforcriteria p pollutants.Inthecaseofairqualitymodeling topredictannualaverageestimatesofambient ` NO2frompointsources,thesocalledOzoneLimitingMethoddoes,asyoupointout,include P proceduresthatcanbeusedtoshowthatnotalloftheNOxemissionsfromasourceare  @ convertedtoNO2intheambientair.Nevertheless,eventhismethodrequirestheinitial !0 assumptionthatallNOxinthestackisemittedasNO2.ThisinstackamountofNO2isthe "  amountthatshouldbereportedasthe_NOx_emissionsforasource,regardlessoftheultimate_NOx_ d conversionratedeterminedtobeapplicableintheareaofconcern. T   Withregardtoyourclaimthatyouhavereceivedconflictinginformationaboutthe 4  appropriatewaytocalculateactualorpotentialemissionstodetermine_NSR_ԀandtitleV $  applicability,webelieveitisimportantthatallStateandlocalairagenciesquantifyandreport   pollutantemissionsinthesamewaythatwedo.Inprevioussituationswherethisissuehas   arisen,wehaveprovidedourpositioninwritingtospecificStatesasappropriate.Moreover,we   intendtodistributethislettertoallEPARegionalOfficessotheycanshareitwiththeir   respectiveStateandlocalairagencies.Inaddition,thisletterwillbepostedonour_NSR_Ԁwebsite p  sothatitwillbeavailableforpublicinformation. `    Iappreciatetheopportunitytobeofserviceandtrustthisinformationishelpful.Ifyou @  haveanyquestions,pleasecontactDan_deRoeck_Ԁat(919)5415593or4 O  5  deroeck.dan@epa.gov.6#O#  7 !J# 0     `     h     Sincerely, t    `     h     /s/signedbyHenryThomas_for_   `     h     JohnS._Seitz_ 4    `     h     Director $    `     h   OfficeofAirQualityPlanning     `     h   andStandards    # XXXX\#XXXX X# XXXXX'#