ÿWPCë 7=<çS!ˆµ_×3È$¸Kl™ëƒÜÑA½±Ÿ>\鈵Lkí̳•§ È)ˆ,Ú”˜U"\uµUòkS˜<¼RÔòM­ðô­hŸˆGˆ0¤Åʯ*œ’@™SŽñ•Ø(3|~Øʈ4ÝÕ]»œ÷W õÓ¡š´Š†[rµÌúùs|yì>ÙÏo¢ô]j©,”Æ>¾ß|1¾£Ë°kkHŸølERb(f`^ªQ–s±¶…°yûu5åfr”)Gò*Ê XŽökõ…= ‘XÖ/]ËÚIðšû<ņ8Š 6¹ 'óHÜ¡v,DÑ£6>dAéK…{Ò‡^Âm±ˆ\ÉÊ-äkÒ×w¤‚Íd™uË% —ÿׄ]îÃÚè^Þ *ï_s˜—,)K ÒD–“œ–"¿×éX· ±ËÜ­‹ Üx\ž½@Ÿ90=Ùx¡ô”éÇ Àª^®`O=éù*+¾j a+Üûb¡ôܦð+ UGê¨W7 ‚Ž­æ׌ÿ<^fzéh"v£¬ ½€Ä‰të*éÐ Ù<û}ŽL”ãU2AÛ"Òhrþ1pfBòJH fsaÎMQ»ÿR…n9í's ?„>ò£PÙ#!U:9 %s 0(y^ ¡w­4±ÅÔ mÖMí 1‡ñ 1ux 0cíNP 1‡R 1‡Ù 1‡`Mç˜LJ8100 PS-File for PDFØÚØÚÚØØÚ0, øð AZ"Arial RegularX($¡¡,cË*äÑY©*DRƒ3|xÿU‹ÿÀÀÀ(5hCEKQW]cioAutoList1I.I.I.I.I.I.I.I.3#37=CIQYag­­1.a.i.(1)(a)(i)1)a)(;3£$´´Ô2#ÔÚ  Ú0Ú  Ú.Ô3  Ôà0  à(š½CEKQW]cioAutoList2A.A.A.A.A.A.A.A.(ª½CEKQW]cioAutoList3A.A.A.A.A.A.A.A.(º½CEKQW]cioAutoList4A.A.A.A.A.A.A.A.Ý ƒ!ÝÝ  ÝÔ_ÔÓ  ÓÔ‡¼¦9»XXÔò òÑ  ÑU.S.€Environmental€Protection€AgencyÐ ° ÐÌUpgrading€MOBILE€to€Include€Particulate€EmissionsÌProposed€Project€Descriptionó óÔ#†XߣX»¼¦97#ÔÐ ì< ÐÌMarch€12,€2001ÌÓ+Ó€ÌÓL€ 5h(3 LÓÝ ‚3£ ÝÝ  Ýòòò òóóÝ‚3£–ÝÔ25hÔÚ  ÚIÚ  Ú.Ô3  Ôà0  àÝ  ÝIntroduction݃3£–Ê݌в (#(# ÐŒÝ  ÝÌà  àó óÔ_ÔOTAQÔ_Ôððs€Assessment€and€Modeling€Center€is€undertaking€a€project€to€integrateÐ Š Ú  Ðthe€calculation€of€highway€vehicle€particulate€air€emissions€into€MOBILE6.€€€TheseÏemissions€are€currently€estimated€with€the€separate€PART5€model€which€is€nowÏoutdated.€€We€considered€several€other€options€for€producing€an€updated€mobileÏsource€particulate€model,€including€updating€PART5€separately,€or€creating€aÏspreadsheet€based€on€recent€Ô_ÔrulemakingÔ_Ô€models.€€Combining€the€PART€and€MOBILEÏmodels,€however,€is€a€prominent€recommendation€of€òòModeling€MOBILE€SOURCEÐ î> ÐEmissionsóó,€the€National€Academy€of€Science€€Research€Councilððs€review€of€MOBILE.€€€Ð Ö& ÐThis€approach€takes€advantage€of€an€integrated€model€development€process€in€Ô_ÔOTAQÔ_Ô,Ïwill€benefit€future€releases€of€MOBILE€as€well€as€PART,€and€will€eliminate€significantÏduplication€of€technical€material€between€the€two€models.€€It€will€also€make€thingsÏsimpler€for€users€who€will€be€given€a€single,€consistent€interface€for€both€functions.ÏWeððve€determined€therefore€to€pursue€the€option€of€integrating€PART5€and€MOBILE6€Ïand€to€call€the€product€of€this€effort€ð ðMOBILE6.1.ððÌÌà  àOur€objective€is€to€quickly€produce€a€MOBILE6.1€that€takes€into€account€dataÏand€Ô_ÔrulemakingsÔ_Ô€of€the€past€6€years,€including€the€fuel€sulfur€level€reductions€that€areÏnow€mandated.€€Based€on€stakeholder€input,€EPA€has€concluded€that€there€is€a€greatÏneed€for€improved€particulate€modeling€capability€this€year.€€Thus€we€have€set€a€goal€ofÏreleasing€a€model€no€later€than€September€30,€2001,€and€hopefully€sooner.€€ThisÏmeans€that€MOBILE6.1€must€be€limited€to€correcting€the€major€deficiencies€andÏshortcomings€of€PART5.€ÌÌà  àWe€believe€this€can€be€accomplished€most€efficiently€by€incorporating€workÏwhich€is€highly€regarded€and€already€complete.€€The€most€important€component€will€beÏto€incorporate€mobile€source€particulate€emission€factors€recently€developed€by€theÏState€of€California€for€EMFAC2000.€€€These€are€based€on€the€most€recent€and€relevantÏtest€data€as€described€in€Section€10.2€of€the€EMFAC2000€technical€support€document.€ÏEPA€helped€fund€much€of€the€data€collection€and€the€California€model,€which€providesÏestimates€of€both€PM2.5€and€PM10,€€has€undergone€extensive€review.€€ÌÌà  àThe€project€schedule€does€not€allow€for€new€test€data€to€be€collected€or€for€newÏemission€factor€algorithms€to€be€developed€which€would€require€extensive€review,Ïtesting€and€coding.€€This€type€of€work€would€push€the€project€into€a€several€year€timeÏframe.€Ìâ âÐ -P(, Ðà  àFurther€improvements€to€the€estimation€of€mobile€source€particulate€emissionsÏâ âwill€be€made€in€the€course€of€the€longer€term€effort€to€produce€an€entire€NewÏGeneration€of€mobile€source€air€pollution€Models€(Ô_ÔNGMÔ_Ô).€€The€Ô_ÔNGMÔ_Ô€will€fully€implementÏthe€National€Academy€of€Science€recommendations,€will€be€based€on€an€extensiveÏdatabase€of€emission€measurements€made€during€actual€operation€of€in„use€vehiclesÏand€will€provide€a€framework€for€allocating€emission€estimates€to€much€smallerÏgeographic€areas€and€time€periods.€ÌÌà  àThe€following€sections€describe€in€more€detail€what€will,€and€will€not,€be€updatedò òÐ à 0 Ðó óin€MOBILE6.1€relative€to€PART5:Ð Æ   ÐÌò òII.€€What€òòWillóó€be€Changed€in€MOBILE6.1ó óòòóóÐ ’â  ÐÌA.à  àMost€of€the€basic€emission€factors€used€to€calculate€exhaust€particulateÐ d´  Ðemissions€will€be€updated.€€The€new€factors€will€be€based€on€those€used€in€ÏEMFAC2000,€a€model€developed€by€the€State€of€California€Air€Resources€Board.€€AsÏalready€mentioned,€the€advantage€of€using€the€calculations€from€EMFAC2000€is€thatÏthey€are€based€on€the€latest€data€available.€€€Their€use€also€represents€a€step€towardsÏharmonizing€EPAððs€models€with€Californiaððs,€which€is€another€recommendation€of€theÏNational€Academy€of€Science.€€The€form€of€these€emission€factors€and€calculation€willÏrequire€significant,€but€to€some€extent€worthwhile,€€elaboration€of€the€current€PARTÏmodel.€€€The€new€factors,€for€example,€include€vehicle€deterioration.ÌÌà  àEMFAC2000€does€not€include€emission€factors€to€calculate€the€idle€exhaustÏparticulate€emissions€of€heavy€duty€diesel€trucks.€€€€This€option€of€the€current€PARTÏmodel€will€therefore€be€removed€to€avoid€the€inconsistency€of€MOBILE6.1€basing€idleÏemissions€on€old€data€and€very€low€speed€emissions€on€the€new€data.€€This€also€meansÏthat€MOBILE6.1€users€will€estimate€idle€particulate€matter€emissions€the€same€wayÏMOBILE6.0€users€estimate€idle€emissions€of€Ô_ÔHCÔ_Ô,€CO,€and€NOX,€which€is€by€calculatingÏemissions€at€an€average€speed€of€2.5€miles€per€hour.€€ÌÌà  àThe€exhaust€particulate€emissions€of€Zero€Emissions€Vehicles€(Ô_ÔZEVsÔ_Ô)€will€beÏconsidered€to€be€zero,€since€neither€PART5€nor€EMFAC2000€contain€exhaustÏparticulate€emission€estimates€for€them.€€Their€tire€and€brake€wear€emissions€will€beÏassumed€to€be€the€same€as€gasoline„fueled€vehicles.€ÌÌà  àThe€exhaust€particulate€emissions€of€€Natural€Gas€Fueled€Vehicles€(Ô_ÔNGVsÔ_Ô)€willÏbe€considered€to€be€the€same€as€gasoline€fueled€vehicles,€operating€on€very€low€sulfurÏfuel.€€Neither€PART5€nor€EMFAC2000€contain€exhaust€particulate€emission€estimatesÏfor€them€but€preliminary€data€supplied€by€the€industry€indicates€their€emissions€areÏcomparable€to€gasoline„fueled€vehicles.€€€Their€tire€and€brake€wear€emissions€will€beÏassumed€to€be€the€same€as€gasoline„fueled€vehicles.€ÌÌà  àOther€mobile€source€emissions€calculated€by€PART,€such€as€tire€wear,€brakeÏwear,€€and€gaseous€SO2€will€not€be€updated€by€California€emission€factors,€but€some€ofÏthese€will€be€updated€in€other€ways,€as€described€in€the€items€which€follow.€Ð $-t(- ЇB.à  àThe€calculation€of€fugitive€dust€from€paved€and€unpaved€roads€will€be€removed.€Ð ° ÐThe€formulas€used€in€PART5€to€estimate€these€emissions€are€outdated.€€EPAððs€Ô_ÔOAQPSÔ_ÔÏhas€been€the€source€for€these€calculation€methods€and€has€decided€to€produce€a€Ïseparate€modeling€tool€€that€will€produce€estimates€for€road€dust€particulate€as€aÏfunction€of€vehicle€miles€of€travel.€ÌÌC.à  àAs€discussed€in€the€Introduction,€we€will€combine€the€upgraded€PART€model€withÐ  d ÐMOBILE6.ÌÌà  àMOBILE6€input€data€will€be€used€wherever€it€applies€to€PART,€including€vehicleÏregistration,€diesel€fraction,€and€mileage€accumulation€information.€€MOBILE6Ïð ðcommand„styleðð€€inputs€will€be€added€to€supply€the€few€remaining€inputs€needed€byÏPART.ÌÌà  àA€single,€consolidated€MOBILE6.1€Userððs€Guide€will€be€produced.ÌÌà  àDatabase€style€reporting€of€particulate€emissions€will€be€fully€integrated€into€theÏMOBILE6.0€database€output€reporting€of€Ô_ÔHCÔ_Ô,€CO,€and€NOX.€€€€PARTððs€descriptive€Ïoutput€will€remain€separate€from€the€output€reports€currently€produced€by€MOBILE6Ïbecause€a€single,€combined€report€would€be€too€complicated€for€the€user€and€tooÏdifficult€to€produce.€€ÌÌD.à  àPART's€calculation€of€sulphate€particulate€and€gaseous€SO2€exhaust€emissionsÐ tÄ Ðwill€be€updated€to€account€for€the€sulfur€level€of€fuel€€(Both€gasoline€and€diesel).€€ThisÏupgrade€was€planned,€but€not€fully€implemented€in€PART5.€€€It€is€essential€to€model€theÏeffects€of€low€sulfur€fuels,€given€what€we€now€know€about€sulfur€effects.€€€€Ìò òÌó óE.à  àWe€will€remove€the€calculation€of€"indirect€sulfate"€(i.e.€sulfate€formed€in€the€airÐ øH Ðfrom€vehicle€emissions€such€as€SO2)€from€the€model.€€EPA€now€requires€that€indirectÏsulfate€emissions€be€handled€with€air€quality€modeling€rather€than€as€a€mobile€sourceÏemission.€ÌÌF.à  àWe€will€remove€the€effect€of€I/M€programs€from€the€calculation€of€particulateÐ v!Æ  Ðemissions.€€The€effect€of€I/M€is€very€minor€in€PART5.€€Only€lead€particulate€emissionsÏare€affected€by€I/M€programs€in€PART5.€€The€effect€involved€leaded€gasoline,€and€theÏneed€for€modeling€leaded€gasoline€has€declined.€€(Also€it€would€be€difficult€and€notÏworthwhile,€to€try€to€relate€€PART5's€"Yes/No"€input€for€I/M€to€MOBILE6's€elaborate€I/MÏinputs.)ÌÌG.à  àMOBILE6.1€will€include€the€effects€of€regulations€on€particulate€emissions€thatÐ À'#' Ðhave€gone€into€effect€since€PART5.€€This€includes€the€effects€of€the€Tier2€regulationÏand€the€Heavy€Duty€2007€rule.€€The€effects€of€the€2004€rule€are€already€incorporated€inÏEMFAC2000's€calculations.€€ÌÌH.à  àMOBILE6.1€will€add€the€ability€to€estimate€exhaust€emissions€of€ammonia.€€ThisÐ >,Ž', Ðmay€be€based€on€the€emission€factors€and€calculation€method€described€in€EPA€ReportÐ $-t(- ÐNumber€EPA/AA/Ô_ÔCTABÔ_Ô/PA/81„20,€entitled€ð ðDetermination€of€a€Range€of€Concern€forÏMobile€Source€Emissions€of€Ammoniaðð.€€€While€this€dates€from€1981,€we€are€not€awareÏof€a€better€basis€for€such€calculations€but€we€are€examining€more€recent€data.€ÌÌI.à  àMOBILE6.1€will€improve€PARTððs€ð ðdescriptiveðð€output€report€to€clearly€organizeÐ H˜ Ðthe€emission€typesò ò€ó óand€components.€€Users€of€PART5€often€found€the€report€confusingÐ . ~ Ðand€found€that€emission€component€values€did€not€always€ð ðadd€upðð€in€the€naturallyÏexpected€fashion€to€the€subtotals€and€totals€shown.€ÌÌJ.à  àPART5's€option€to€model€special€driving€cycles€for€buses€(CBD€and€heavy€urban)Ð Ì   Ðwill€be€removed€from€MOBILE6.1.€€€EMFAC2000€does€not€include€this€feature€and€theÏnewer€data€do€not€include€tests€upon€which€such€estimates€could€be€based.€€MOBILE6Ïdoes€not€include€this€feature€for€Ô_ÔHCÔ_Ô,€CO,€or€NOX,€and€this€feature€does€not€seem€to€beÏof€importance€to€users.€ÌÌK.à  àWe€will€improve€the€programming€code€of€PART5€and€MOBILE6€to€someÐ 0€  Ðdegree.€ÌÌL.€à  àEPA€will€be€developing€policy€guidance€in€the€future€for€implementingÐ â2 ÐMOBILE6.1ÌÌÌò òIII.€€Some€Aspects€of€PART5€that€òòWill€Notóó€be€Changed.ó óÐ zÊ ÐÌSection€II€above€is€intended€to€be€complete.€€The€intent€of€this€section€is€to€highlightÏsome€specific€aspects€of€the€model€that€will€not€be€changed.€€ÌÌA.€€While€total€sulfur€emissions€(gaseous€SO2€plus€direct€sulfate€particulate€emissions)Ïwill€be€calculated€based€on€fuel€sulfur€content:ÌÌà0  à1.€Assumptions€in€PART5€as€to€the€fraction€of€sulfur€which€takes€each€form€willÏnot€be€updated.Ð (#(# ÐÌà0  à2.€€Other€than€ammonia,€no€new€exhaust€emission€components€will€be€added€toÏthe€model.€€While€some€have€suggested€that€additional€sulfur€compounds€shouldÏbe€modeled,€neither€PART5€nor€EMFAC2000€provide€a€basis€for€doing€so.€ÏPART5€actually€has€a€more€elaborate€breakdown€of€exhaust€particulate€thanÏEMFAC2000.€€€PART5€considers€exhaust€particulate€to€consist€of€leadÏparticulate,€a€soluble€organic€fraction€of€carbon„based€Ô_ÔparticulatesÔ_Ô€(SOF),€aÏremaining€portion€of€carbon„based€Ô_ÔparticulatesÔ_Ô€(Ô_ÔRCPÔ_Ô),€and€direct€sulfateÏÔ_ÔparticulatesÔ_Ô€(SO4).€€This€structure€will€be€retained.€Ð (#(# ÐÌB.à  àThe€brake€wear€and€tire€wear€calculation€portions€of€PART5€will€not€be€updated.€Ð x*È%* Ð(Though€some€consideration€was€given€to€updating€tire€wear,€we€have€tentativelyÏdecided€against€it€because€PART5's€estimates€fall€within€the€range€of€uncertainty€of€theÏnewer€studies.)€€Ð *-z(- ЇC.à  àNo€effects€of€I/M€or€Ô_ÔOBDÔ_Ô€programs€on€particulate€emission€levels€will€beÐ ° Ðmodeled.€€This€was€discussed€above,€and€is€being€restated€here€for€clarity.ÌÌD.à  àNo€effect€of€Ô_ÔHCÔ_Ô€standards€on€particulate€emissions€will€be€modeled.€€This€isÐ b² Ðimplicit€in€the€above€discussion,€but€is€being€stated€here€for€clarity.€ÌÌE.à  àEMFAC2000€does€not€appear€to€have€updated€factors€for€light€duty€dieselÐ  d Ðvehicles€or€for€heavy€„€heavy€duty€(HHD)€gasoline€vehicles,€so€the€basic€emission€ratesÏfor€the€exhaust€particulate€emissions€of€these€types€of€vehicles€will€be€retained€fromÏPART5.€€(These€kinds€of€vehicles€constitute€a€negligible€portion€of€the€vehicle€fleet.)Ìà  àà ` àà ¸ àà  àà h àà À àà  àà p àà È àÌF.à  àEffects€of€ambient€temperature€on€particulate€emission€levels€will€not€beÐ ’â  Ðmodeled.€€Neither€PART5€nor€EMFAC2000€attempt€to€model€such€effects.ÌÌ