[Federal Register Volume 67, Number 84 (Wednesday, May 1, 2002)]
[Proposed Rules]
[Pages 21607-21612]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-10727]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
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  Federal Register / Vol. 67, No. 84 / Wednesday, May 1, 2002 / 
Proposed Rules  

[[Page 21607]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[UT-001-0042; FRL-7203-8]


Approval and Promulgation of Air Quality Implementation Plans; 
State of Utah; Salt Lake County--Trading of Emission Budgets for 
PM10 Transportation Conformity

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On March 15, 2002, the Governor of Utah submitted a proposed 
revision to the Utah State Implementation Plan (SIP) that would allow 
trading from the motor vehicle emissions budget for primary Particulate 
Matter of 10 microns or less in diameter (PM10) to the motor 
vehicle emissions budget for Nitrogen Oxides (NOX) which is 
a PM10 precursor. This trading mechanism will allow Salt 
Lake County to increase their NOX budget by decreasing their 
PM10 budget by an equivalent amount in order to achieve 
motor vehicle emissions budgets for NOX and PM10 
that may then be used to demonstrate transportation conformity with the 
Salt Lake County PM10 attainment demonstration element of 
the SIP. The trading between emissions budgets to demonstrate 
transportation conformity is allowable, as long as a trading mechanism 
is approved into the SIP. In his letter of March 15, 2002, the Governor 
asked that EPA parallel process a proposed revision to the 
PM10 attainment demonstration SIP including a new rule, 
R307-310 ``Salt Lake County: Trading of Emission Budgets for 
Transportation Conformity.''
    In this action, EPA is proposing approval and soliciting public 
comment on the proposed SIP revision, involving Utah's new Rule R307-
310, that would allow the trading of on-road mobile source primary 
PM10 emissions to PM10 precursor on-road mobile 
source NOX emissions on a one to one basis. The resulting 
adjusted budgets may then be used for demonstrating transportation 
conformity with the Salt Lake County PM10 attainment 
demonstration element of the SIP.

DATES: Written comments must be received on or before May 31, 2002.

ADDRESSES: Written comments may be mailed to: Richard R. Long, 
Director, Air and Radiation Program, Mailcode     8P-AR, United States 
Environmental Protection Agency, Region VIII, 999 18th Street, Suite 
300, Denver, Colorado 80202-2466
    Copies of the documents relevant to this action are available for 
public inspection during normal business hours at the following 
offices: United States Environmental Protection Agency, Region VIII, 
Air and Radiation Program, 999 18th Street, Suite 300, Denver, Colorado 
80202-2466.
    Copies of the State documents relevant to this action are available 
for public inspection at: Utah Department of Environmental Quality, 
Division of Air Quality, 150 North 1950 West, Salt Lake City, Utah 
84114-4820.

FOR FURTHER INFORMATION CONTACT: Tim Russ, Air and Radiation Program, 
Mailcode 8P-AR, United States Environmental Protection Agency, Region 
VIII, 999 18th Street, Suite 300, Denver, Colorado 80202-2466 Telephone 
number: (303) 312-6479

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we'', 
``us'', or ``our'' are used we mean the Environmental Protection 
Agency.

I. What Is the Purpose of This Action?

    With this action, we are utilizing our parallel processing 
procedure for consideration of a revision to the Utah SIP. Parallel 
processing allows EPA to propose rulemaking on a SIP revision, and 
solicit public comment, at the same time the State is processing the 
SIP revision. The schedule provided with the Governor's March 15, 2002, 
submittal indicated that the Utah Air Quality Board (UAQB) proposed the 
SIP revision for a 30-day State public comment period beginning on 
April 1, 2002, and ending on April 30, 2002. The State will conduct a 
public hearing during this 30-day time frame. The Governor's submittal 
indicates that final action by the UAQB is anticipated by May 13, 2002. 
When the Governor submits the final SIP revision to us for approval, we 
will consider any comments received on our proposed rule and proceed 
with a final rulemaking action. However, should the State substantially 
change the proposed SIP revision, before the Governor submits the final 
version to us, we will re-propose and again solicit public comment on 
the State amended SIP revision before we take final rulemaking action. 
For further information regarding parallel processing, please see 40 
CFR part 51, Appendix V, section 2.3.1.
    In this action, we are proposing approval and soliciting public 
comment regarding the Governor's March 15, 2002, submittal of Utah's 
proposed new Rule R307-310 that will allow certain trading of emission 
budgets for the purposes of transportation conformity for 
PM10 for Salt Lake County.

II. What is the State's Process to Submit these Materials to EPA?

    Section 110(k) of the CAA addresses our actions on submissions of 
revisions to a SIP. The CAA requires States to observe certain 
procedural requirements in developing SIP revisions for submittal to 
us. Section 110(a)(2) of the CAA requires that each SIP revision be 
adopted after reasonable notice and public hearing. This public process 
must occur prior to the final revisions being submitted by a State to 
us.
    At the March 13, 2002, UAQB meeting, the UAQB proposed for public 
comment the new Rule R307-310. The UAQB has scheduled a public hearing 
for April 22, 2002, for considering public comment on the above SIP 
revision.

III. EPA's Evaluation of the Proposed Rule R307-310

(a) Background and Purpose

    Transportation conformity is required by the section 176 of the 
Clean Air Act (CAA) to ensure that federally supported highway and 
transit project activities are consistent with (``conform to'') the 
purpose of a state air quality implementation plan (SIP). Conformity to 
the purpose of the SIP means that transportation activities will not 
cause new air quality violations, worsen existing violations, or delay 
timely attainment of the national ambient air quality standards. EPA's 
transportation conformity rule establishes the criteria and procedures 
for determining whether transportation activities conform to the state 
air quality plan.

[[Page 21608]]

    One key provision of EPA's transportation conformity rule (see 40 
CFR part 93) requires a demonstration that emissions from the 
transportation plan and Transportation Improvement Program (TIP) are 
consistent with the emissions budgets in the applicable SIP (40 CFR 
93.118 and 93.124). The transportation emissions budget(s) is defined 
as the level of on-road mobile source emissions relied upon in the SIP 
to attain or maintain compliance with the National Ambient Air Quality 
Standard (NAAQS) in the nonattainment or maintenance area.
    In this particular instance, the NAAQS involved is PM10 
, the nonattainment area is Salt Lake County, the motor vehicle 
emissions budgets involve direct emissions of PM10 and 
NOX, the latter as a precursor to the formation of 
PM10, and the applicable SIP is the July 8, 1994, EPA-
approved Utah PM10 attainment demonstration SIP (see 59 FR 
35036) with respect to the Salt Lake County element.
    Transportation conformity is demonstrated when future year's 
projected on-road mobile source's emissions for a particular pollutant 
or precursor are estimated to be at or below the on-road motor 
vehicle's emissions budget for that pollutant or precursor in the 
applicable SIP. With reference to conformity for the PM10 
NAAQS for Salt Lake County, conformity must be demonstrated separately 
for the PM10 and NOX budgets established in the 
Salt Lake County PM10 attainment demonstration element of 
the SIP. However, emissions can be traded between the PM10 
and NOX budgets if there is an approved rule in the SIP to 
allow trading to take place as per 40 CFR 93.124(c). The provision in 
40 CFR 93.124(c) states:

    ``A conformity demonstration shall not trade emissions among 
budgets which the applicable implementation plan (or implementation 
plan submission) allocates for different pollutants or precursors, 
or among budgets allocated to motor vehicles and other sources, 
unless the implementation plan establishes appropriate mechanisms 
for such trades.''

    With respect to the above conformity rule requirement, the State 
has developed the proposed new Rule R307-310 which will establish an 
on-road mobile source emissions trading mechanism that; (1) involves 
only PM10 and NOX motor vehicle emission budgets 
from the PM10 attainment demonstration SIP, (2) allows 
trading in only one direction from the PM10 budget to the 
NOX budget on a one to one basis, (3) applies only to 
transportation conformity determinations in Salt Lake County in 
conjunction with the PM10 attainment demonstration SIP, and 
(4) is pursuant to 40 CFR part 93.

(b) Proposed New Rule R307-310 Description

    An overview of all portions of the State's new Rule R307-310 is 
provided below:
    1. R307-310 is entitled ``Salt Lake County: Trading of Emission 
Budgets for Transportation Conformity.''
    2. R307-310-1 ``Purpose.'' The stated purpose of this new rule is:
    ``This rule establishes the procedures that may be used to trade a 
portion of the primary PM10 budget when demonstrating that a 
transportation plan, transportation improvement program, or project 
conforms with the motor vehicle emissions budgets in the Salt Lake 
County portion of Section IX, Part A of the State Implementation Plan, 
``Fine Particulate Matter (PM10).''
    3. R307-310-2. ``Definitions.'' This section provides applicable 
definitions:
    ``The definitions contained in 40 CFR 93.101, effective as of July 
1, 2001, are incorporated into this rule by reference. The following 
additional definitions apply to this rule.
    ``Budget'' means the motor vehicle emission projections used in the 
attainment demonstration in the Salt Lake County portion of Section IX, 
Part A of the State Implementation Plan, ``Fine Particulate Matter 
(PM10).''
    ``NOX'' means oxides of nitrogen.
    ``Primary PM10'' means PM10 that is emitted 
directly by a source. Primary PM10 does not include 
particulate matter that is formed when gaseous emissions undergo 
chemical reactions in the ambient air.
    ``Transportation Conformity'' means a demonstration that a 
transportation plan, transportation improvement program, or project 
conforms with the emissions budgets in a state implementation plan, as 
outlined in 40 CFR, Chapter 1, Part 93, ``Determining Conformity of 
Federal Actions to State or Federal Implementation Plans.''
    4. R307-310-3. ``Applicability''. This portion of the rule defines 
its applicability. We note that this rule may only be applied to Salt 
Lake County and only for PM10 :
    ``(1) This rule applies to agencies responsible for demonstrating 
transportation conformity with the Salt Lake County portion of Section 
IX, Part A of the State Implementation Plan, ``Fine Particulate Matter 
(PM10).''
    (2) This rule does not apply to emission budgets from Section IX, 
Part D.2 of the State Implementation Plan, ``Ozone Maintenance Plan.''
    (3) This rule does not apply to emission budgets from Section IX, 
Part C.7 of the State Implementation Plan, ``Carbon Monoxide 
Maintenance Provisions.''
    5. R307-310-4. ``Trading Between Emission Budgets.'' This portion 
of the rule describes the trading mechanism (we note and agree with the 
State that it is appropriate that the primary PM10 budget 
may be used to supplement the NOX budget, but that the 
NOX budget may not be used to supplement the primary 
PM10 budget. EPA agrees with this concept and provides 
further technical justification below.):
    ``(1) The agencies responsible for demonstrating transportation 
conformity are authorized to supplement the budget for NOX 
with a portion of the budget for primary PM10 for the 
purpose of demonstrating transportation conformity for NOX. 
The NOX budget shall be supplemented using the following 
procedures.
    (a) The metropolitan planning organization shall include the 
following information in the transportation conformity demonstration:
    (i) The budget for primary PM10 and NOX for 
each required year of the conformity demonstration, before trading 
allowed by this rule has been applied;
    (ii) The portion of the primary PM10 budget that will be 
used to supplement the NOX budget, specified in tons per day 
using a 1:1 ratio of primary PM10 to NOX, for 
each required year of the conformity demonstration;
    (iii) The remainder of the primary PM10 budget that will 
be used in the conformity demonstration for primary PM10, 
specified in tons per day for each required year of the conformity 
demonstration; and
    (iv) The budget for primary PM10 and NOX for 
each required year of the conformity demonstration after the trading 
allowed by this rule has been applied.
    (b) Transportation conformity for NOX shall be 
demonstrated using the NOX budget supplemented by a portion 
of the primary PM10 budget as described in (a)(ii). 
Transportation conformity for primary PM10 shall be 
demonstrated using the remainder of the primary PM10 budget 
described in (a)(iii).
    (c) The primary PM10 budget shall not be supplemented by 
using a portion of the NOX budget.''

(c) Proposed New Rule R307-310 Technical Justification

    The Governor provided the following technical justification that is 
designed to support the proposed new Rule R307-310 and address the 
specific issue involving mobile sources emissions trading, as 
contemplated by 40 CFR

[[Page 21609]]

93.124(c), for PM10 and NOX. EPA and the UDAQ 
jointly developed the following technical justification:
1. Description
    PM10 is particulate matter with diameters smaller than 
10 micrometers. PM10 consists of solid and/or liquid 
particles of (1) primary particles that are directly emitted 
particulate matter (PM) or PM that quickly condenses upon release and 
(2) secondary particles which are PM that is formed in the atmosphere 
from gaseous precursors. Important gaseous precursors to PM include 
sulfur dioxide (SO2) which converts to sulfate 
(SO4=) particles, nitrogen oxides (NOX) which 
convert to nitrate (NO3-) particles, volatile organic 
compounds (VOCs), some of which convert to secondary organic aerosols, 
and ammonia (NH3) which adds to the mass of sulfate PM and 
allows nitric acid to convert to PM10 in the form of 
ammonium nitrate.
    Currently in Salt Lake County, conformity for PM10 
utilizes PM10 and NOX emission figures that were 
derived from the 1994 EPA-approved PM10 attainment 
demonstration SIP (see 59 FR 35036, July 8, 1994). Since the regulatory 
goal is to achieve and maintain attainment of the NAAQS and conformity 
related to total PM10, not individual components, it should 
not matter in conformity analysis whether PM10 consists of 
directly emitted (primary) PM10 or secondary nitrate 
PM10 formed in the atmosphere from precursor NOX 
gas emissions, provided the budgets for PM10 and 
NOX are consistent with a demonstration of attainment. This 
technical justification outlines the scientific rationale for why 
excess NOX emissions can be offset on a 1 to 1 basis with 
available PM10 budget in the Salt Lake County attainment 
demonstration, and why this is conservative (i.e., protective of the 
environment).
2. What Fraction of the NOX Emissions Convert to 
PM10?
    Each ton of gaseous NOX that gets converted to 
PM10 creates more than a ton of PM10 because the 
molecular weight of ammonium nitrate PM10 is greater than 
the molecular weight of NOX gaseous emissions. Considering 
the ratio of the molecular weights of the NOX precursor gas 
and the resulting ammonium nitrate aerosol (PM10), a ton of 
NOX that is converted from a gas to a particle can form as 
much as 1.74 tons of PM10.
    However, not all NOX emissions are converted because it 
takes time to convert NOX to nitric acid (HNO3), 
which is the necessary gaseous precursor to ammonium nitrate 
PM10. These reactions generally occur at rates of 1 to 10 
percent per hour. Thus, it would take at least 10 hours to fully 
convert to nitric acid. After this initial conversion, only a fraction 
of the gaseous nitric acid will condense as ammonium nitrate 
PM10, depending on equilibrium considerations. Finally, 
during the gas-to-particle conversion process, deposition will remove a 
significant amount of material. Throughout this process of 
NOX conversion to nitric acid, and then to PM10 
and deposition, an equivalent amount of directly emitted 
PM10 is having a much larger effect on PM10 
concentration. Directly emitted PM10 has an effect on 
concentration immediately upon release, while NOX emissions 
require hours to register their effect.
    The conversion of NOX to PM10 has been 
discussed at EPA at least since 1996:

    ``The conversion process may depend on several variables, 
including the availability of chemical reactants in the atmosphere 
for the conversion process, and the difference in mass between the 
PM10 precursor molecule and the PM10 particle 
that the precursor reacts to become. Another concern is that the 
rate of conversion of the precursor to PM10 may be so 
long that the precursor may not entirely convert to PM10 
within the same nonattainment area. Thus, there would be less 
counteracting effect and no net improvement to air quality in the 
area. Under the EPA's proposal, a source of a PM10 
precursor may offset its increased emissions with the same precursor 
type or PM10 (or a combination of the two). In this 
situation, a net improvement in air quality would be assured. At 
this point, however, the EPA is not proposing to allow offsetting 
among different types of PM10 precursors, or offsetting 
PM10 increases with reduction in PM10 
precursors, because the Agency does not now have a scientific basis 
to propose conversion factors. (61 FR 38305, July 23, 1996)''

    This particular technical justification, for the proposed Rule 
R307-310, to only allow the trading of the PM10 budget to 
the NOX budget, but to not allow the substitution of 
NOX for primary PM10, is consistent with the 
above-referenced EPA statements. Therefore, both EPA's existing 
information and the most current scientific data support allowing 
primary PM10 to be traded to the NOX budget, 
while continuing to demonstrate attainment, in the proposed new Rule 
R307-310 SIP revision.
3. Consistency with the EPA-Approved Salt Lake County PM10 
SIP
    The 1994 approved PM10 SIP element for Salt Lake County 
contains an attainment demonstration that is based on a combination of 
Chemical Mass Balance (CMB) modeling and a micro-inventory for the 
area. The CMB model matches chemical profiles on filters collected on 
high pollution days with profiles of emission sources in the area to 
determine the degree of impact from individual sources. The modeling 
was complicated because the majority of the PM10 collected 
on the filters in Salt Lake County was a result of chemical reactions 
that occur in the atmosphere. Nitrogen oxides (NOX) and 
sulfur dioxide (SO2) are gases that undergo chemical reactions to form 
nitrates and sulfates that are measured as PM10 on the 
filters. Primary PM10 emissions from all source categories, 
including mobile sources, were evaluated using CMB to determine the 
impact at each of the monitoring sites. Mobile source primary 
PM10 impacts were estimated using a ``finger print'' of 
emissions from this category. Nitrates could not be differentiated 
among the major source groups using CMB. The mobile source contribution 
to the total measured nitrate was determined using a straight emission 
inventory apportionment.
    An analysis based on the SIP's control strategy worksheet for the 
``Air Monitoring Center'' (AMC) site was performed, which is the 
controlling monitoring site for Salt Lake County (it has the highest 
projected year 2003 PM10 concentration, at 147.4 g/
m3).
    Page 35 of the State's originally submitted PM10 SIP \1\ 
provides the CMB-based attainment demonstration calculations for the 
year 2003, and page 36 of the originally submitted PM10 SIP 
provides the corresponding results for all the years covered by the SIP 
revision.
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    \1\ The Utah PM10 SIP, that includes the Salt Lake 
County element, was submitted by the Governor on November 15, 1991 
and was approved by EPA on July 8, 1994 (59 FR 35036).
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    In 2003, the total primary PM10 contribution from mobile 
sources was estimated to be 37.4 g/m3. (This is the 
sum of all the individual mobile source primary PM10 
categories: leaded, diesel, unleaded, road dust, and brakewear.) The 
total nitrate contribution from mobile sources was estimated to be 16.7 
g/m3.
    The existing Salt Lake County PM10 SIP motor vehicle 
emission budgets are 40.3 tons per day of primary PM10, and 
32.3 tons per day of NOX. These budgets were derived by the 
Wasatch Front Regional Council (WFRC), the Metropolitan Planning 
Organization or MPO, using the Salt Lake County PM10 SIP 
element attainment year (2003) inventories, adjusted for winter vehicle 
miles traveled (VMT) rates.
    At the AMC monitor, the CMB modeling contained in the SIP indicates

[[Page 21610]]

that 40.3 tons per day of PM10 results in a concentration of 
37.4 g/m3 of primary PM10, and 32.3 tons 
per day of NOX results in a concentration of 16.7 
g/m3 of nitrate. Thus, each ton of PM10 
emissions produces 0.93 g/m3 of primary 
PM10, and each ton of NOX produces 0.52 
g/m3 of nitrate. In equivalent terms, each ton of 
NOX emissions has the same ambient impact as 0.56 tons of 
PM10 emissions (0.52 divided by 0.93). Thus, substituting 
PM10 emissions for NOX emissions in the budgets 
would produce lower overall emissions and continue to demonstrate 
attainment in the Salt Lake Countys PM10 nonattainment area.
4. Impact of the PM10 and NOX Trading Rule on 
Other Pollutants
    In addition to being a nonattainment area for PM10, Salt 
Lake County is part of the Salt Lake/Davis Counties ozone maintenance 
area.\2\ Salt Lake City is also a carbon monoxide (CO) maintenance 
area.\3\ However, this proposal does not have an adverse impact on 
these two pollutants. For ozone, the approved ozone maintenance plan 
has its own motor vehicle NOX emissions budget, which has 
been set at a level demonstrated to keep Salt Lake and Davis Counties 
in attainment with the   1-hour ozone standard. We note that the ozone 
maintenance plan actually has separate motor vehicle NOX 
emissions budgets for Salt Lake and Davis Counties, but it allows WFRC 
to demonstrate conformity for each county individually or on a combined 
basis at their discretion. Nothing in this proposal for the new Rule 
R307-310 changes the Salt Lake/Davis Counties ozone motor vehicle 
emissions budgets for NOX and WFRC must continue to comply 
with these budgets in order to demonstrate conformity for ozone. 
Therefore, there will be no adverse impact on continued attainment of 
the 1-hour ozone standard for Salt Lake County. In fact, WFRC's most 
recent conformity analyses show that the area complies with the Salt 
Lake/Davis Counties combined existing 1-hour ozone NOX motor 
vehicle emissions budget by a wide margin in future years.
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    \2\ The Salt Lake/Davis Counties ozone (1-hour standard) 
redesignation to attainment was approved by EPA on July 17, 1997 (62 
FR 38213).
    \3\ The Salt Lake City carbon monoxide redesignation to 
attainment was approved by EPA on January 22, 1999 (64 FR 3216).
---------------------------------------------------------------------------

    With respect to carbon monoxide, NOX emissions are not 
precursors to carbon monoxide and nothing in this proposal for the new 
Rule R307-310 would be expected to impact Salt Lake City's current CO 
maintenance status. Like ozone, the CO maintenance plan has its own CO 
motor vehicle emissions budget, which has been set at a level 
demonstrated to keep Salt Lake City in attainment with the CO standard. 
Nothing in this proposal changes this CO motor vehicle emissions budget 
and as stated above for ozone, WFRC has been able to demonstrate 
conformity with this CO motor vehicle emissions budget by a wide 
margin.
5. Conclusion
    On the basis of the above analyses and since NOX has 
less impact on a per ton basis than primary PM10 emissions, 
there will be a net benefit on ambient air concentrations of 
PM10 when excess NOX emissions are offset on a 
1:1 basis with available PM10 budget in the transportation 
conformity demonstration. Therefore, using a portion of the motor 
vehicle PM10 emissions budget to offset excess on-road 
mobile sources NOX emissions on a 1:1 basis continues to 
demonstrate attainment of the PM10 NAAQS and is conservative 
and justifiable.
    The analyses provided in this technical justification were designed 
to show that the trading ratio of PM10 to NOX was 
less than 1:1, but they do not establish what this ratio should be. 
Until a more extensive analysis is completed, that will be subject to 
EPA approval, it is not possible to determine the exact amount of 
NOX that would be needed to offset an increase in 
PM10 emissions. Therefore, trading of PM10 to 
NOX emissions can only be justified in one direction at this 
time.

IV. Evaluation/Reconciliation--Implementation and Periodic Review 
of the Effectiveness of the New Rule R307-310 for Salt Lake County

    The proposed new Rule, R307-310, establishes the procedures that 
may be used to trade a portion of the primary PM10 motor 
vehicle emissions budget to the NOX motor vehicle emissions 
budget when demonstrating that a transportation plan, transportation 
improvement program, or project conforms with the motor vehicle 
emissions budgets for PM10 and NOX in the Salt 
Lake County element of the Utah PM10 portion of the State 
Implementation Plan. As stated above in the technical justification, 
the Salt Lake/Davis Counties ozone maintenance plan and the Salt Lake 
City carbon monoxide maintenance plan are not expected to be affected 
by this new rule.
    However, because trading of motor vehicle emissions budgets for 
conformity purposes is not common, there is the possibility that 
unforseen circumstances may arise in the future that may affect the 
implementation of the new Rule R307-310. Therefore, a periodic review 
of the effectiveness of this new rule is important to ensure there are 
not any unintended adverse consequences due to this proposed motor 
vehicle emissions budget trading rule.
    In a letter dated March 22, 2002, from Richard Sprott, Director, 
Utah Division of Air Quality to Richard Long, Director, Air and 
Radiation Program for EPA Region 8, the State committed to evaluate the 
performance of the proposed new rule, R307-310, every three years to 
determine its overall effect and whether it has adversely affected the 
EPA-approved Salt Lake/Davis Counties ozone maintenance plan or the 
EPA-approved Salt Lake City carbon monoxide maintenance plan. The State 
also committed to make appropriate recommendations to the UAQB, as 
necessary, to remedy adverse effects. The language in the State's March 
22, 2002, letter further indicates that if needed, EPA may exercise its 
authority to perform a SIP call that is consistent with 40 CFR 
51.493(f)(1)(i) should the State fail to make the necessary revisions.
    EPA believes this commitment by the State to be adequate. However, 
we also note that EPA is not precluded from performing our own 
evaluation analysis of the proposed trading rule at any time that we 
deem appropriate. Further, if we determine there are adverse air 
quality effects associated with the implementation of the proposed new 
Rule, R307-310, or if we determine that the State has failed to make 
the necessary revisions to remedy identified adverse effects in either 
the PM10, ozone, or CO SIPs, EPA may exercise our authority 
to issue a SIP call consistent with the provisions of section 110(k)(5) 
of the Clean Air Act (CAA) as amended in 1990. To clarify, although the 
State has indicated in its letter of March 22, 2002, that a SIP call 
may happen consistent with 40 CFR 51.493(f)(1)(i), EPA is in no way 
only restricted to this particular section of the CFR. If necessary, 
EPA will issue a SIP call, as provided under section 110(k)(5) of the 
CAA, as we deem appropriate. In conjunction with a SIP call 
contemplated under section 110(k)(5) of the CAA, we will also consider 
establishing a schedule of sanctions as provided under section 179 of 
the CAA.

V. Consideration of CAA section 110(l)

    Section 110(l) of the CAA states that a SIP revision cannot be 
approved if the revision would interfere with any applicable 
requirement concerning attainment and reasonable further

[[Page 21611]]

progress towards attainment of a NAAQS or any other applicable 
requirements of the CAA. In view of the State's rule language for its 
new Rule R307-310, the analyses presented above in section ``(c) 
Proposed New Rule R307-310 Technical Justification'', and the fact that 
NOX has less impact on a per ton basis than primary 
PM10 emissions there will be a net benefit on ambient air 
concentrations of PM10 when excess NOX emissions are offset 
on a one to one basis. Therefore, the proposed new Rule R307-310, that 
would allow the trading of a portion of the PM10 motor 
vehicle emissions budget to the NOX motor vehicle emissions 
budget on a one to one basis, continues to demonstrate attainment of 
the PM10 NAAQS and is conservative and justifiable. We have concluded 
that our proposed approval of the State's new Rule R307-310 will meet 
the intent of section 110(l) of the CAA.

VI. Proposed Rulemaking Action and Request for Public Comment

    We are soliciting public comment on all aspects of this proposed 
rule. As stated above, we are proposing approval of the Governor's 
March 15, 2002, proposed revision to the Utah State Implementation 
Plan, involving a new Rule, R307-310, that would allow the trading of a 
portion of the PM10 motor vehicle emissions budget to the 
NOX motor vehicle emissions budget. This trading mechanism 
will allow a portion of the PM10 motor vehicle emissions 
budget to be applied to the NOX motor vehicle emissions 
budget on a 1:1 ratio, thus increasing the NOX motor vehicle 
emissions budget and decreasing the PM10 motor vehicle 
emissions budget by an equivalent amount. These adjusted budgets may 
then be used for transportation conformity purposes with the Salt Lake 
County PM10 attainment demonstration element of the SIP. 
Send your comments in duplicate to the address listed in the ADDRESSES 
section of this proposed rule. We will consider your comments in 
deciding our final action if your letter is received before May 31, 
2002.

Administrative Requirements

(a) Executive Order 12866

    The Office of Management and Budget (OMB) has exempted this 
regulatory action from Executive Order 12866, entitled ``Regulatory 
Planning and Review.''

(b) Executive Order 13045

    Protection of Children from Environmental Health Risks and Safety 
Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) is 
determined to be ``economically significant'' as defined under 
Executive Order 12866, and (2) concerns an environmental health or 
safety risk that EPA has reason to believe may have a disproportionate 
effect on children. If the regulatory action meets both criteria, the 
Agency must evaluate the environmental health or safety effects of the 
planned rule on children, and explain why the planned regulation is 
preferable to other potentially effective and reasonably feasible 
alternatives considered by the Agency.
    This rule is not subject to Executive Order 13045 because it is not 
economically significant under Executive Order 12866 and it does not 
involve decisions intended to mitigate environmental health or safety 
risks.

(c) Executive Order 13132

    Federalism (64 FR 43255, August 10, 1999) revokes and replaces 
Executive Orders 12612 (Federalism) and 12875 (Enhancing the 
Intergovernmental Partnership). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' Under Executive Order 13132, EPA may not issue a 
regulation that has federalism implications, that imposes substantial 
direct compliance costs, and that is not required by statute, unless 
the Federal government provides the funds necessary to pay the direct 
compliance costs incurred by State and local governments, or EPA 
consults with State and local officials early in the process of 
developing the proposed regulation. EPA also may not issue a regulation 
that has federalism implications and that preempts State law unless the 
Agency consults with State and local officials early in the process of 
developing the proposed regulation.
    This rule will not have substantial direct effects on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government, as specified in Executive Order 13132, because it 
merely approves state rules implementing a federal standard, and does 
not alter the relationship or the distribution of power and 
responsibilities established in the Clean Air Act. Thus, the 
requirements of section 6 of the Executive Order do not apply to this 
rule.

(d) Executive Order 13175 (Consultation and Coordination With Indian 
Tribal Governments)

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.''
    This rule does not have tribal implications. It will not have 
substantial direct effects on tribal governments, on the relationship 
between the Federal government and Indian tribes, or on the 
distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. 
Thus, Executive Order 13175 does not apply to this rule.

(e) Executive Order 13211 (Energy Effects)

    This rule is not subject to Executive Order 13211 ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355 (May 22, 2001)) because it is not a 
significant regulatory action under Executive Order 12866.

(f) Regulatory Flexibility

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions.
    This rule will not have a significant impact on a substantial 
number of small entities because SIP approvals under section 110 and 
subchapter I, part D of the Clean Air Act do not create any new 
requirements, but simply propose approval requirements that the State 
is already imposing. Therefore, because the Federal SIP approval does 
not create any new requirements, I certify that this action will not 
have a significant economic impact on a substantial number of small 
entities. Moreover, due to the nature of the Federal-State relationship 
under the Clean Air Act,

[[Page 21612]]

preparation of flexibility analysis would constitute Federal inquiry 
into the economic reasonableness of state action. The Clean Air Act 
forbids EPA to base its actions concerning SIPs on such grounds. Union 
Electric Co., v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 42 U.S.C. 
7410(a)(2).

(g) Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate; or to 
the private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that the approval action proposed does not 
include a Federal mandate that may result in estimated costs of $100 
million or more to either State, local, or tribal governments in the 
aggregate, or to the private sector. This Federal action proposes to 
approve pre-existing requirements under State or local law, and imposes 
no new requirements. Accordingly, no additional costs to State, local, 
or tribal governments, or to the private sector, result from this 
action.

(h) National Technology Transfer and Advancement Act

    Section 12 of the National Technology Transfer and Advancement Act 
(NTTAA) of 1995 requires Federal agencies to evaluate existing 
technical standards when developing a new regulation. To comply with 
NTTAA, EPA must consider and use ``voluntary consensus standards'' 
(VCS) if available and applicable when developing programs and policies 
unless doing so would be inconsistent with applicable law or otherwise 
impractical.
    The EPA believes that VCS are inapplicable to this action. Today's 
action does not require the public to perform activities conducive to 
the use of VCS.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Intergovernmental relations, Nitrogen dioxide, Ozone, Particulate 
matter, Reporting and recordkeeping requirements.

    Dated: April 22, 2002.
Robert E. Roberts,
Regional Administrator, Region VIII.
[FR Doc. 02-10727 Filed 4-30-02; 8:45 am]
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