Federal Register/Vol. 69, No. 97 / Wednesday, May 19, 2004 / 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 of the

MOBILE6.2 motor vehicle emissions

factor model for official use in

particulate matter (PMo and PM 2.

5) SIPs

and transportation conformity

determinations outside of California.

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 PM 2.

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 of PM emissions for use by

state and local governments to meet

Clean Air Act requirements.

EPA is also approving and

announcing the availability of new

methods for the estimation of reentrained road dust emissions from cars,

trucks, buses, and motorcycles on paved

and unpaved roads for PMo and PM 2.

5

state implementation plans (SIPs) and

transportation conformity analyses.

These new methods are incorporated in

the December 2003 edition of Chapter

13 of Compilation of Air 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

PM 10 emissions.

EPA strongly encourages areas to use

the interagency consultation process to

examine how MOBILE6.2 and the

December 2003 AP-42 methods will

affect future transportation conformity

analyses, so, if necessary, PM10 SIPs and

motor vehicle emissions budgets can be

revised with MOBILE6.2 and AP-42 or

transportation plans and programs can

be revised as appropriate prior to the

end of the conformity grace period.

DATES: EPA's approval of the

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 on this notice,

please send an e-mail to EPA at

mobile@epa.gov or contact EPA at (734)

214-4636 for technical model questions

about MOBILE6.2. Please send an e-mail

to EPA at info.chief@epa.gov or contact

EPA at (919) 541-1000 for technical

questions about the December 2003 AP42 methods.

SUPPLEMENTARY INFORMATION:

Availability of Models and Support

Materials

Copies of the official version of the

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 on the Use of MOBILE6.2 and

the December 2003 AP-42 Method for

Re-Entrained Road Dust for SIP

Development and Transportation

Conformity"; EPA's "Technical

Guidance on the Use of MOBILE6.2 for

Emission Inventory Preparation"; and a

list of Frequently Asked Questions

about MOBILE6.2. EPA will continue to

update this Web site in 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 of the 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 of subscribers and a

confirmation message will be sent to

your e-mail address. Whenever a

message is posted to the EPAMOBILENEWS listserver by the

listserver owner (the Assessment and

Standards Division of the EPA Office of

Transportation and Air Quality), a copy

of that message will be sent to every

person who has subscribed.

You can remove yourself from the list

by sending another message to the

listserver address. This message must be

sent from the same e-mail address that

you used to subscribe, and should

contain the message: unsubscribe EPAMOBILENEWS.

Copies of the official version of the

December 2003 edition of Sections

13.2.1 and 13.2.2 of AP-42 can be found

at www.epa.gov/ttn/chief/ap42/ch13/

index.html. In the rest of this document,

unless otherwise indicated, "AP-42"

refers to the December 2003 edition of

Sections 13.2.1 and 13.2.2 of AP-42.

L What Is MOBILE6.2 and How Is It

Different From MOBILE6?

MOBILE is an EPA emissions factor

model for estimating pollution from onroad motor 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 of motor vehicle

emissions at the national and local

level. These inventories are used to

make decisions about air pollution

policies and programs at the local, state

and national level. Inventories based on

MOBILE are also used to meet the

federal Clean Air Act's state

implementation plan (SIP) and

transportation conformity requirements.

The previous version of MOBILE,

known as MOBILE6, calculated

emissions of volatile 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 PM 2 5, and emission

factors for particulate precursors, to the

original MOBILE6 model. In other

words, MOBILE6.2 allows the

estimation of emission 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 of the

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 2 vehicle standards.

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Functionally, MOBILE6.2 now replaces

MOBILE6 as the highway vehicle

emission factor model that EPA will

maintain and support.

I. What Is the Impact of MOBILE6.2 on

Ozone and CO SIPs and Conformity

Determinations?

Although MOBILE6.2 includes some

corrections and enhancements to parts

of the model that estimate emissions of

HC, NOx, and CO, the impact of these

changes is generally small. Even though

MOBILE6.2 is very similar to MOBILE6

for these pollutants, states and local

agencies outside of California should

use MOBILE6.2 for future HC, NOx, and

CO SIPs and conformity analyses in

order to take full advantage of the

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 of MOBILE6.2 does not start

a new 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. What Are the December 2003 AP-42

Methods?

Motor vehicle emissions inventories

for PM are comprised of four

components: exhaust emissions,

emissions from brake wear, emissions

from tire wear, and re-entrained road

dust. MOBILE6.2 does not include the

capability of estimating the emissions of

re-entrained road dust as the result of

motor vehicle activity. EPA has

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

of MOBILE6.2 and the December 2003

AP-42 Method for Re-Entrained Road

Dust for SIP Development and

Transportation Conformity" (available

at http://www.epa.gov/otaq/modelsl

mobile6/mobil6.2 letter.pdf). The

following discussion of the use of AP42 in SIPs and conformity

determinations also applies to approved

alternatives to AP-42.

IV. PM10 SIP Policy for MOBILE6.2 and

AP-42

EPA has articulated its policy

regarding the use of MOBILE6.2 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 and Transportation

Conformity." Today's action highlights

certain aspects of the 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 Availability of

Related SIP Policies to obtain the

MOBILE6.2 and AP-42 policy guidance.

PM 10 SIPs that EPA has already

approved are not typically required to

be revised now that EPA has 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 of effort

that States have already undertaken in

PMo SIP development with previous

models or methods. States that have

already submitted PMo SIPs or will

submit PM 0 SIPs shortly after EPA's

approval of MOBILE6.2 and AP-42 are

not required to revise these SIPs simply

because a new motor vehicle emissions

model is now available. States can

choose to use MOBILE6.2 in these SIPs,

for example, if it is determined that

future conformity determinations would

be ensured through such a SIP revision.

However, EPA does not believe that a

State's use of an earlier model such as

PART5 should be an obstacle to EPA

approval for SIPs that have been or will

soon be submitted, assuming that such

SIPs are otherwise approvable and

significant SIP work has already

occurred (e.g., attainment modeling for

an attainment SIP has already been

completed with an earlier model). It

would be 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 a timely manner.

States should use MOBILE6.2 and

AP-42 where PMo SIP development is

in its initial stages or hasn'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

will be submitted late in 2004 should be

based on MOBILE6.2 and AP-42 since

there is adequate time to incorporate the

new model's results. MOBILE6.2 and

AP-42 should be incorporated into

these SIPs since emissions estimates in

these models are based on the best

information currently available, as

required by Clean Air Act section

172(c)(3) and 40 CFR 51.112(a)(1).

V. PM10 Transportation Conformity

Policy for MOBILE6.2 and AP-42

Transportation conformity is a Clean

Air Act 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 of federal 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 on the most recent 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 of a conformity

grace period in the preamble to the 1993

transportation conformity rule (58 FR

62211):

"EPA and [the Department of

Transportation (DOT)] will consider

extending the grace period if the effects of the

new emissions model are so significant that

previous SIP demonstrations of what

emission levels are consistent with

attainment would be substantially affected.

In such cases, States should have an

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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 of the grace period, including

the degree of change in emissions

models and the effects of the new model

on the transportation planning process

(40 CFR 93.111).

Upon consideration of all of these

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

should use the interagency consultation

process to examine how MOBILE6.2 and

AP-42 will affect their future

conformity determinations.

However, the grace period will be

shorter than 2 years for PM1 o if an 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

(but not 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 of the 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 a faster

time frame. When the grace period ends

on May 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

of the 2-year grace period must be based

on MOBILE6.2 and AP-42, even if the

SIP is based on PART5. As discussed

above, the grace period for new

conformity analyses would be shorter

for PM 10 if an area revised its SIP and

budgets with MOBILE6.2 and AP-42

and such budgets 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 how MOBILE6.2 and

AP-42 will affect future conformity

determinations, so, if necessary, PM1 o

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 of the 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 of the grace

period may continue to rely on earlier

models such as PART5. Conformity

determinations for transportation

projects may also be based on an earlier

model if the regional analysis was begun

before the end of the grace period, and

if the final environmental document for

the project is issued no more than three

years after the issuance of the draft

environmental document (see 40 CFR

93.111(c)). The interagency consultation

process should be used if it is unclear

whether an analysis based on an earlier

model was begun before the end of the

grace period.

The release of MOBILE6.2 and AP-42

does not trigger the need for quantitative

conformity hot-spot modeling to

estimate concentrations of PM10 at this

time. However, qualitative hot spot

analyses are still required in PM10

nonattainment and maintenance areas.

VL. PM 2 .

5 SIP and Transportation

Conformity Policy for MOBILE6.2 and

AP-42

EPA has not yet finalized

implementation policy for the PM 2.

5

National Ambient Air Quality Standards

(NAAQS). However, when that policy is

finalized and PM 2.5 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, and re-entrained road dust

emissions in PM 2.

5 SIPs and conformity

determinations, until they are replaced

by newer models or methods. No PM 2.

5

SIPs have previously been done using

other models and therefore, the release

of MOBILE6.2 and AP-42 does not

constitute a change in models which

might result in inconsistencies between

the SIP and transportation analyses. As

a result, there is no need for a PM 2.

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

PM 2.5 conformity analyses, until they

are replaced by newer approved

methods or models.

Dated: May 11, 2004.

Margo Tsirigotis Oge,

Director, Office of Transportation and Air

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 and Company,

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 or before

July 19, 2004.

ADDRESSES: To submit a written

objection or hearing request follow the

detailed instructions as provided in

Unit VIII. of the SUPPLEMENTARY

INFORMATION. EPA has established a

docket for this action under Docket ID

number OPP-2004-0130. All

documents in the docket are listed in

the EDOCKET index at http://

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 and will be

publicly available only in hard copy

form. Publicly available docket

materials are available either

electronically in EDOCKET or in hard

copy at the Public Information and

Records Integrity Branch (PIRIB), Rm.

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