Federal Register/Vol. 69, No. 97

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### /Rules and Regulations

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 51 [FRL-7663-6]

Official Release of the MOBILE6.2 Motor Vehicle Emissions Factor Model and the December 2003 AP-42 Methods for Re-Entrained Road Dust

AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of availability.

SUMMARY: EPA is approving and announcing the availability ofthe MOBILE6.2 motor vehicle emissions factor model for official use in particulate matter (PMo and PM2. 5)SIPs and transportation conformity determinations outside ofCalifornia. MOBILE6.2 is an update to MOBILE6 which adds the capability to estimate direct exhaust and brake and tire wear particulate matter emission factors for PMo and PM2. 5, and exhaust emission factors for particulate precursors to the MOBILE6 model. MOBILE6.2 is a substantial improvement over previous methods for estimating PM emissions and incorporates EPA's most current estimates ofPM emissions for use by
state and local governments to meet Clean Air Act requirements.

EPA is also approving and announcing the availability ofnew methods for the estimation ofreentrained road dust emissions from cars, trucks, buses, and motorcycles on paved and unpaved roads for PMo and PM2. 5 state implementation plans (SIPs) and transportation conformity analyses. These new methods are incorporated in the December 2003 edition ofChapter 13 ofCompilation ofAir Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources.

Today's action also starts time periods after which MOBILE6.2 and the December 2003 AP-42 methods are required to be used in new transportation conformity analyses for PM10 emissions.

EPA strongly encourages areas to use the interagency consultation process to examine howMOBILE6.2 and the December 2003 AP-42 methods will affect future transportation conformity analyses, so, ifnecessary, PM10 SIPs and
motor vehicle emissions budgets canbe revised with MOBILE6.2 and AP-42 or transportation plans andprograms can be revised as appropriate prior to the end ofthe conformity grace period. DATES: EPA's approval ofthe MOBILE6.2 emissions factor model and December 2003 AP-42 methods for reentrained road dust is effective May 19, 2004. See below for further information regarding how today's approval starts time periods after which MOBILE6.2 and the December 2003 AP-42 methods

are required in new transportation conformity analyses and certain SIP and
motor vehicle emissions budget revisions.

FOR FURTHER INFORMATION CONTACT: If you have questions onthis notice, please send an e-mail to EPA at mobile@epa.govor contact EPA at (734) 214-4636 for technical model questions about MOBILE6.2. Please send an e-mail
to EPA at info.chief@epa.govor contact EPA at (919) 541-1000 for technical questions about the December 2003 AP42 methods.

SUPPLEMENTARY INFORMATION: Availability ofModels and Support Materials

Copies ofthe official version ofthe MOBILE6.2 model are available on EPA's MOBILE Web site, http:// www.epa.gov/otaq/m6.htm.The MOBILE Web site also contains the following support materials for implementing the new model: a detailed MOBILE6.2 User's Guide; EPA's "Policy Guidance onthe Use ofMOBILE6.2 and the December 2003 AP-42 Method for Re-Entrained Road Dust for SIP Development and Transportation Conformity"; EPA's "Technical Guidance onthe Use ofMOBILE6.2 for Emission Inventory Preparation"; and a list ofFrequently Asked Questions about MOBILE6.2. EPA will continue to update this Web sitein the future as other MOBILE6.2 support materials are developed.

Individuals who wish to receive EPA
announcements related to the MOBILE model should subscribe to the EPAMOBILENEWS e-mail listserver. To subscribe to the EPA-MOBILENEWS listserver, write the following in the body ofthe e-mail message: subscribe EPA-MOBILENEWS FIRSTNAME LASTNAME where FIRSTNAME and LASTNAME is your

name (for example: John Smith) and send the e-mail to the EPA Listserver at listserver@unixmail.rtpnc.epa.gov.

Your e-mail address will then be added to the list ofsubscribers and a confirmation message will be sent to your e-mail address. Whenever a message is posted to the EPAMOBILENEWS listserver bythe listserver owner (the Assessment and Standards Division ofthe EPA Office of Transportation andAir Quality), acopy ofthatmessage willbe sent to every person who has subscribed. You can remove yourselffrom the list by sending another message to the listserver address. This message must be
sent from the same e-mail address that you usedto subscribe, and should contain the message: unsubscribe EPAMOBILENEWS.

Copies ofthe official version ofthe December 2003 edition ofSections 13.2.1 and 13.2.2 ofAP-42 can be found
at www.epa.gov/ttn/chief/ap42/ch13/ index.html.In the rest ofthis document, unless otherwise indicated, "AP-42" refers to the December 2003 edition of Sections 13.2.1 and 13.2.2 ofAP-42.

L WhatIsMOBILE6.2 andHowIsIt DifferentFromMOBILE6?

MOBILE is an EPA emissions factor model for estimating pollution from onroadmotor vehicles in states outside of California. The model accounts for the emission impacts of factors such as changes in vehicle emission standards, changes in vehicle populations and activity, and variation in local conditions such as temperature, humidity, fuel quality, and air quality
programs.

MOBILE is used to calculate current and future inventories ofmotor vehicle emissions at the national and local level. These inventories are usedto make decisions about air pollution policies and programs at the local, state and national level. Inventories based on MOBILE are also usedto meet the federal CleanAir Act's state implementation plan (SIP) and transportation conformity requirements.

The previous version ofMOBILE, known as MOBILE6, calculated emissions ofvolatile organic compounds (VOCs), nitrogen oxides (NOx) and carbon monoxide (CO) from passenger cars, motorcycles, buses, and light-duty and heavy-duty trucks. MOBILE6.2 is an update to MOBILE6 which adds the capability to estimate direct particulate matter (PM) emission factors for PM10 and PM25, and emission factors for particulate precursors, to the original MOBILE6 model. In other words, MOBILE6.2 allows the estimation ofemission factors for HC (and air toxics), NOx, CO, gaseous SO 2, ammonia, and direct PM from vehicle exhaust and brake and tire wear. MOBILE6.2 also corrects some minor coding errors in the portion ofthe model code that estimates HC, NOx, and CO emission factors, and it adds the capability of entering hourly relative humidity values. MOBILE6.2 also incorporates some revisions to CO emission factors for cars and light-duty trucks that meet national low emission vehicle (NLEV), low emission vehicle (LEV), and Tier 2vehicle standards. 28830

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Functionally, MOBILE6.2 nowreplaces MOBILE6 asthe highway vehicle emission factor model that EPA will maintain and support.
I. WhatIs theImpactof MOBILE6.2 on OzoneandCO SIPsandConformity Determinations?

Although MOBILE6.2 includes some corrections and enhancements to parts ofthe model thatestimate emissions of HC, NOx, and CO, the impact ofthese changes is generally small. Even though MOBILE6.2 is very similar to MOBILE6 for these pollutants, states and local agencies outside ofCalifornia should

use MOBILE6.2 for future HC, NOx, and CO SIPs and conformity analyses in order to take full advantage ofthe improvements incorporated in this version. SIPs and conformity analyses already in progress with MOBILE6 can be completed using MOBILE6 as determined through the interagency consultation process. Because the changes in HC, NOx, and CO emissions in MOBILE6.2 are generally very small, the release ofMOBILE6.2 does not start

anew grace period before MOBILE6.2 is required to be used for all new transportation conformity analyses in

ozone or CO nonattainment or maintenance areas and it does not trigger the need for any new ozone or CO SIP revisions.

III. WhatAre theDecember2003AP-42 Methods?

Motor vehicle emissions inventories for PM are comprised offour components: exhaust emissions, emissions frombrake wear, emissions from tire wear, and re-entrained road dust.MOBILE6.2 does not include the capability ofestimating the emissions of re-entrained road dust as the result of
motor vehicle activity. EPAhas developed separate revised AP-42 methodologies for estimating reentrained road dust from paved and unpaved roads. These new methods for estimating road dust emission factors for paved and unpaved roads are being incorporated in EPA's document AP-42. These new AP-42 methodologies (AP42, Sections 13.2.1, Paved Roads and 13.2.2, Unpaved Roads, each dated December 2003) replace previous methods for estimating re-entrained road dust emissions for these categories with some limitations. AP-42 is the approved method only for situations for which silt loading, mean vehicle weight, and mean vehicle speed fall within
ranges given in AP-42 section 13.2.1.3 and with reasonably free-flowing traffic. For other conditions, areas may use an appropriate method approved by EPA

on a case-by-case basis. In some areas, alternate methods may be more appropriate than AP-42 given specific local conditions even within the parameters given in AP-42 section 13.2.1.3. State and local agencies should consult with EPA for approval of alternative approaches. This policy is described in more detail in the document "Policy Guidance on the Use ofMOBILE6.2 and the December 2003 AP-42 Method for Re-Entrained Road Dust for SIP Development and Transportation Conformity" (available
athttp://www.epa.gov/otaq/modelsl mobile6/mobil6.2 letter.pdf).The following discussion ofthe use ofAP42 in SIPs and conformity determinations also applies to approved alternatives to AP-42.

IV. PM 10 SIPPolicy forMOBILE6.2 and AP-42

EPA has articulated its policy regarding the use ofMOBILE6.2 and AP-42 in PM 0 SIP development in its "Policy Guidance on the Use of MOBILE6.2 and the December 2003 AP42 Method for Re-Entrained Road Dust for SIP Development andTransportation Conformity." Today's action highlights certain aspects ofthe guidance, but state and local governments should refer to the guidance for more detailed information on how and when to use MOBILE6.2 and AP-42 in attainment and maintenance PMo SIPs, inventory updates, and other PMo SIP submission requirements. See Availabilityof Related SIPPoliciesto obtain the MOBILE6.2 and AP-42 policy guidance.

PM10 SIPs that EPAhas already approved are not typically required to be revised now that EPAhas approved MOBILE6.2 and AP-42. Although MOBILE6.2 and AP-42 should be used in new PM 0 SIP development as expeditiously as possible, EPA also recognizes the time and level ofeffort that States have already undertaken in PMo SIP development with previous models or methods. States that have already submitted PMo SIPs orwill submitPM 0 SIPs shortly after EPA's approval ofMOBILE6.2 andAP-42 are not required to revise these SIPs simply because anew motor vehicle emissions model is now available. States can choose to use MOBILE6.2 in these SIPs, for example, ifitis determined that future conformity determinations would be ensured through such a SIP revision. However, EPA does not believe that a State's use ofan earlier model such as PART5 shouldbe an obstacle to EPA approval for SIPs that have been orwill

soonbe submitted, assuming that such SIPs are otherwise approvable and significant SIP workhas already occurred (e.g., attainment modeling for an attainment SIP has already been completed with an earlier model). It wouldbe unreasonable to require States
to revise these SIPs with MOBILE6.2 and AP-42 since significant work has already occurred, and EPA intends to act on these SIPs in atimely manner.

States should use MOBILE6.2 and AP-42 where PMo SIP development is in its initial stages orhasn't progressed far enough along that switching to MOBILE6.2 and AP-42 would create a significantly adverse impact on State

resources. For example, PMo SIPs that willbe submitted late in 2004 shouldbe based onMOBILE6.2 and AP-42 since there is adequate time to incorporate the

new model's results. MOBILE6.2 and AP-42 shouldbe incorporated into these SIPs since emissions estimates in these models are based on the best information currently available, as required by CleanAir Act section 172(c)(3) and40 CFR 51.112(a)(1).

V.PM 10 Transportation Conformity Policy forMOBILE6.2 andAP-42 Transportation conformity is a Clean AirAct requirement to ensure that federally supported highway and transit activities are consistent with ("conform to") the SIP. Conformity to a SIP means that a transportation activity will not

cause or contribute to new air pollution violations; worsen existing violations; or delay timely attainment offederal air quality standards.

The transportation conformity rule (40 CFR part 93) requires that conformity analyses be based on the latest motor vehicle emissions model approved by EPA. Section 176(c)(1) of the Clean Air Act states that ". * * * [t]he determination of conformity shall be based onthe mostrecent estimates of emissions, and such estimates shall be determined from the most recent population, employment, travel, and congestion estimates * * *." When we approve new emissions models such as MOBILE6.2 and AP-42, a grace period is established before the models are required for conformity analyses. The conformity rule provides for a grace period for new emissions models of between 3-24 months.

EPA articulated its intentions for establishing the length ofa conformity grace period in the preamble to the 1993 transportation conformity rule (58 FR 62211):

"EPAand [the Department of Transportation (DOT)] will consider extending the grace period ifthe effects ofthe

new emissions model are so significant that previous SIP demonstrations ofwhat emission levels are consistent with attainment would be substantially affected. In such cases, States should have an 28831

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opportunity to revise their SIPs before MPOs
must use the model's new emissions factors."
In consultation with the DOT, EPA considers many factors in establishing the length ofthe grace period, including the degree of change in emissions models and the effects ofthe new model

onthe transportation planning process (40 CFR 93.111).

Upon consideration of all ofthese factors, EPA is establishing a 2-year grace period, which begins today and ends on May 19, 2006, before MOBILE6.2 and AP-42 are required for

new PM10 conformity analyses in most

cases. During this grace period, areas shoulduse the interagency consultation
process to examine howMOBILE6.2 and AP-42 will affect their future conformity determinations.

However, the grace period will be shorter than 2years for PM1oifan area revises its SIP and budgets with MOBILE6.2 and AP-42 and such budgets become applicable for conformity purposes prior to the end of the 2-year grace period. For example, if

an area revises a previously submitted (butnot approved) PART5-based PM10 SIP with MOBILE6.2 and AP-42 and EPA finds the revised budgets adequate for conformity, such budgets would apply for conformity on the effective date ofthe Federal Register notice announcing EPA's adequacy finding.

During the grace period, areas can use earlier models such as PART5 for PM10 conformity determinations or choose to

use MOBILE6.2 and AP-42 on afaster time frame. When the grace period ends

onMay 19, 2006, MOBILE6.2 will become the only approved motor vehicle emissions model for new PM10 transportation conformity analyses outside of California and AP-42 will become the approved method for estimating re-entrained road dust unless

an alternate method is approved as described in section III above. In general, this means that all new PM10 conformity analyses started after the end ofthe 2-year grace period mustbe based

onMOBILE6.2 and AP-42, even ifthe SIP isbased on PART5. As discussed above, the grace period for new conformity analyses would be shorter for PM 10 ifan area revised its SIP and budgets with MOBILE6.2 and AP-42 and suchbudgets became applicable for conformity purposes prior to the end of the 2-year grace period. EPA strongly encourages areas to use the consultation process to examine howMOBILE6.2 and AP-42 will affect future conformity determinations, so, ifnecessary, PM1o SIPs and budgets can be revised with MOBILE6.2 and AP-42 or transportation plans and programs can be revised as appropriate prior to the end ofthe grace period.

Finally, the conformity rule provides

some flexibility for analyses that are started before or during the grace period. Regional conformity analyses that began before the end ofthe grace period may continue to rely on earlier models such as PART5. Conformity determinations fortransportation projects may also be based on an earlier model ifthe regional analysis was begun before the end ofthe grace period, and ifthe final environmental document for the project is issued no more than three
years after the issuance ofthe draft environmental document (see 40 CFR 93.111(c)). The interagency consultation
process should be used ifit isunclear whether an analysis based on an earlier model was begun before the end ofthe
grace period.

The release ofMOBILE6.2 and AP-42 does not trigger the need for quantitative conformity hot-spot modeling to estimate concentrations ofPM10 at this time. However, qualitative hot spot analyses are still required in PM10 nonattainment andmaintenance areas.

VL. PM 2.5 SIPandTransportation ConformityPolicy forMOBILE6.2 and AP-42

EPA has not yet finalized implementation policy for the PM2. 5 National Ambient Air Quality Standards (NAAQS). However, when that policy is finalized andPM2
.5 nonattainment areas have been designated, MOBILE6.2 (except in California) and AP-42 (except in areas where another dust methodology has been approved) will be the approved models for estimating
motor vehicle exhaust, brake and tire

wear, andre-entrained road dust emissions in PM2. 5 SIPs and conformity determinations, until they are replaced by newer models ormethods. No PM2.5 SIPs have previously been done using other models and therefore, the release ofMOBILE6.2 and AP-42 does not constitute a change in models which might result in inconsistencies between the SIP andtransportation analyses. As

aresult, there is no need for aPM2. 5 conformity grace period for MOBILE6.2 and AP-42. MOBILE6.2 (except in California) and AP-42 (except in areas where another dust methodology has been approved) must be used in all PM2.5 conformity analyses, until they

are replaced by newer approved methods ormodels. Dated: May 11, 2004. Margo Tsirigotis Oge, Director,OfficeofTransportation andAir Quality. [FR Doc. 04-11340 Filed 5-18-04; 8:45 am]

BILLING CODE 6560-50-P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180 [OPP-2004-0130; FRL-7359-1]
Indoxacarb; Time-Limited Pesticide Tolerance

AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule.
SUMMARY: This regulation establishes a time-limited tolerance for residues/ combined residues of indoxacarb, (S)- methyl 7-chloro-2,5-dihydro-2- [[(methoxycarbonyl) [4- (trifluoromethoxy) phenyl]amino]carbonyl] indeno[1,2- e][1,3,4]oxadiazine-4a(3H)-carboxylate, and its R-enantiomer, (R)-methyl 7- chloro-2,5-dihydro-2- [[(methoxycarbonyl)[4- (trifluoromethoxy) phenyl]amino]carbonyl]indeno [1,2- e][1,3,4]oxadiazine-4a(3H)-carboxylate, in or on cherry, sweet and cherry, tart. E.I.DuPont de Nemours andCompany, DuPont Crop Protection requested this tolerance under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA). The tolerance will expire

on May 21, 2007.
DATES: This regulation is effective May 19, 2004. Objections and requests for hearings must be received on orbefore July 19, 2004.
ADDRESSES: To submit awritten objection or hearing request follow the detailed instructions asprovided in Unit VIII. ofthe SUPPLEMENTARY INFORMATION. EPA has established a docket for this action under Docket ID number OPP-2004-0130. All documents inthe docket are listed in the EDOCKET index athttp:// www.epa.goviedocket. Although listed in the index, some information is not publicly available, i.e., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet andwill be publicly available only in hard copy form. Publicly available docket materials are available either electronically inEDOCKET or in hard copy at the Public Information and Records Integrity Branch (PIRIB), Rm. 28832

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