Approval and Promulgation of Implementation Plans; New Mexico; Interstate Transport of Pollution; Revisions to Prevention of Significant Deterioration Regulations, 52692-52701 [2010-21384]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 75, Number 166 (Friday, August 27, 2010)]
[Proposed Rules]
[Pages 52692-52701]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-21384]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2009-0656; FRL-9193-6]


Approval and Promulgation of Implementation Plans; New Mexico; 
Interstate Transport of Pollution; Revisions to Prevention of 
Significant Deterioration Regulations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve a State Implementation Plan (SIP) 
revision submitted by the State of New Mexico for the purpose of 
addressing the ``good neighbor'' provisions of Clean Air Act (CAA) 
section 110(a)(2)(D)(i) for the 1997 8-hour ozone National Ambient Air 
Quality Standards (NAAQS or standards) and the 1997 PM2.5 
NAAQS. This SIP revision addresses the requirement that the State of 
New Mexico's SIP have adequate provisions to prohibit air emissions 
from adversely affecting another state's

[[Page 52693]]

air quality through interstate transport. In this action, EPA is 
proposing to approve the New Mexico Interstate Transport SIP provisions 
that address the requirement of section 110(a)(2)(D)(i)(I) that 
emissions from New Mexico sources do not interfere with maintenance of 
the 1997 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS in any 
other state. In addition, EPA is proposing to approve the provisions of 
this SIP submission that address the requirement of section 
110(a)(2)(D)(i)(II) that emissions from New Mexico sources do not 
interfere with measures required in the SIP of any other state under 
part C of the CAA to prevent significant deterioration of air quality. 
For purposes of the 1997 8-hour ozone NAAQS, EPA is also proposing to 
approve a SIP revision that modifies New Mexico's Prevention of 
Significant Deterioration (PSD) SIP for the 1997 8-hour ozone NAAQS to 
include nitrogen oxides (NOX) as an ozone precursor. This 
action is being taken under section 110 and part C of the Clean Air Act 
(the Act or CAA).

DATES: Comments must be received on or before September 27, 2010.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2009-0656, by one of the following methods:
     Federal e-Rulemaking Portal: https://www.regulations.gov.
     Follow the online instructions for submitting comments.
     EPA Region 6 ``Contact Us'' Web site: https://epa.gov/region6/r6coment.htm. Please click on ``6PD (Multimedia)'' and select 
``Air'' before submitting comments.
     E-mail: Mr. Guy Donaldson at donaldson.guy@epa.gov. Please 
also send a copy by e-mail to the person listed in the FOR FURTHER 
INFORMATION CONTACT section below.
     Fax: Mr. Guy Donaldson, Chief, Air Planning Section (6PD-
L), at fax number 214-665-7263.
     Mail: Mr. Guy Donaldson, Chief, Air Planning Section (6PD-
L), Environmental Protection Agency, 1445 Ross Avenue, Suite 1200, 
Dallas, Texas 75202-2733.
     Hand or Courier Delivery: Mr. Guy Donaldson, Chief, Air 
Planning Section (6PD-L), Environmental Protection Agency, 1445 Ross 
Avenue, Suite 1200, Dallas, Texas 75202-2733. Such deliveries are 
accepted only between the hours of 8 a.m. and 4 p.m. weekdays, and not 
on legal holidays. Special arrangements should be made for deliveries 
of boxed information.
    Instructions: Direct your comments to Docket No. EPA-R06-OAR-2009-
0656. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through www.regulations.gov 
or e-mail. The https://www.regulations.gov Web site is an ``anonymous 
access'' system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through https://www.regulations.gov your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses.
    Docket: All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Air Planning Section 
(6PD-L), Environmental Protection Agency, 1445 Ross Avenue, Suite 700, 
Dallas, Texas 75202-2733. The file will be made available by 
appointment for public inspection in the Region 6 FOIA Review Room 
between the hours of 8:30 a.m. and 4:30 p.m. weekdays except for legal 
holidays. Contact the person listed in the FOR FURTHER INFORMATION 
CONTACT paragraph below or Mr. Bill Deese at 214-665-7253 to make an 
appointment. If possible, please make the appointment at least two 
working days in advance of your visit. There will be a 15 cent per page 
fee for making photocopies of documents. On the day of the visit, 
please check in at the EPA Region 6 reception area at 1445 Ross Avenue, 
Suite 700, Dallas, Texas.
    The state submittal is also available for public inspection during 
official business hours, by appointment, at the New Mexico Environment 
Department, Air Quality Bureau, 1190 St. Francis Drive, Santa Fe, New 
Mexico 87502.

FOR FURTHER INFORMATION CONTACT: Emad Shahin, Air Planning Section 
(6PD-L), Environmental Protection Agency, Region 6, 1445 Ross Avenue, 
Suite 700, Dallas, Texas 75202-2733, telephone (214) 665-6717; fax 
number (214) 665-7263; e-mail address shahin.emad@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,'' 
``us,'' or ``our'' is used, we mean the EPA.

Outline

I. What action is EPA taking?
II. What is a SIP?
III. What is the background for this action?
IV. What is EPA's evaluation of the State's submission?
V. Statutory and Executive Order Reviews

I. What action is EPA taking?

    We are proposing to approve a submission from the State of New 
Mexico demonstrating that New Mexico has adequately addressed two of 
the required elements of CAA section 110(a)(2)(D)(i), the elements that 
require that the State Implementation Plan prohibit air pollutant 
emissions from sources within a state from interfering with maintenance 
of the relevant NAAQS in any other state, and from interfering with 
measures required to prevent significant deterioration of air quality 
in any other state. We are proposing to determine that emissions from 
sources in New Mexico do not interfere with the maintenance of the 1997 
8-hour ozone NAAQS or of the 1997 PM2.5 NAAQS, or with 
measures required to prevent significant deterioration of air quality, 
with regards to these ozone or PM2.5 NAAQS in any other 
state. In a separate prior action, we have addressed the element of 
section 110(a)(2)(D)(i) that pertains to prohibiting air pollutant 
emissions from within New Mexico from significantly contributing to 
nonattainment of the 1997 8-hour ozone and 1997 PM2.5 NAAQS 
in any other state (75 FR 33174). The remaining section 110(a)(2)(D)(i) 
element which pertains to interference with measures required to 
protect visibility in any other state will be addressed in a future 
rulemaking.
    In conjunction with our proposed finding that emissions from 
sources in

[[Page 52694]]

New Mexico are not interfering with any other state's PSD program, we 
are also proposing to approve a portion of the SIP revision submitted 
by the State of New Mexico with rule revisions to regulate NOx 
emissions in its PSD permit program as a precursor to ozone. At this 
time, EPA is not taking action on other portions of the SIP revisions 
submitted by New Mexico together with the PSD revision.\1\ EPA intends 
to act on the other revisions submitted together with the PSD program 
revisions at a later time.
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    \1\ As noted later in this action, these revisions are separate 
from the New Mexico PSD revisions and are to 20.2.2 NMAC, 
Definitions and 20.2.79 NMAC, Permits-Nonattainment areas.
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    EPA proposes to approve the foregoing revisions relevant to section 
110(a)(2)(D)(i) and the revisions to the PSD program pursuant to 
section 110 and part C of the CAA.

II. What is a SIP?

    Section 110(a) of the Clean Air Act (CAA) requires each state to 
develop a plan that provides for the implementation, maintenance, and 
enforcement of the national ambient air quality standards (NAAQS). EPA 
establishes NAAQS under section 109 of the CAA. Currently, the NAAQS 
address six criteria pollutants: carbon monoxide, nitrogen dioxide, 
ozone, lead, particulate matter, and sulfur dioxide.
    The plan developed by a state is referred to as the state 
implementation plan (SIP). The content of the SIP is specified in 
section 110 of the CAA, other provisions of the CAA, and applicable 
regulations. SIPs can be extensive, containing state regulations or 
other enforceable measures and various types of supporting information, 
such as emissions inventories, monitoring networks, and modeling 
demonstrations.
    A primary purpose of the SIP is to provide the air pollution 
regulations, control strategies, and other means or techniques 
developed by the state to ensure that the ambient air within that state 
meets the NAAQS. However, another important aspect of the SIP is to 
ensure that emissions from within the state do not have certain 
prohibited impacts upon the ambient air in other states through 
interstate transport of pollutants. This SIP requirement is specified 
in section 110(a)(2)(D) of the CAA. Pursuant to that provision, each 
state's SIP must contain provisions adequate to prevent, among other 
things, emissions that interfere with maintenance of the NAAQS in any 
other state or interfere with measures required to be included in the 
SIP of any other state to prevent significant deterioration of air 
quality in such other state.
    States are required to update or revise SIPs under certain 
circumstances. One such circumstance is EPA's promulgation of a new or 
revised NAAQS. Each state must submit these revisions to EPA for 
approval and incorporation into the federally-enforceable SIP.

III. What is the background for this action?

    On July 18, 1997, EPA promulgated new NAAQS for 8-hour ozone and 
for fine particulate matter (PM2.5). This action is being 
taken in response to the promulgation of the 1997 8-hour ozone NAAQS 
and 1997 PM2.5 NAAQS. This action does not address the 
requirements for the 2006 PM2.5 NAAQS or the 2008 8-hour 
ozone NAAQS; those standards will be addressed in later actions.
    Section 110(a)(1) of the CAA requires states to submit SIPs to 
address a new or revised NAAQS within 3 years after promulgation of 
such standards, or within such shorter period as EPA may prescribe. 
Section 110(a)(2) lists the elements that such new SIPs must address, 
as applicable, including section 110(a)(2)(D)(i), which pertains to 
interstate transport of certain emissions. On August 15, 2006, EPA 
issued its ``Guidance for State Implementation Plan (SIP) Submissions 
to Meet Current Outstanding Obligations Under Section 110(a)(2)(D)(i) 
for the 8-Hour Ozone and PM2.5 National Ambient Air Quality 
Standards'' (2006 Guidance). EPA developed the 2006 Guidance to make 
recommendations to states for making submissions to meet the 
requirements of section 110(a)(2)(D)(i) for the 1997 8-hour ozone 
standards and the 1997 PM2.5 standards.
    As identified in the 2006 Guidance, the ``good neighbor'' 
provisions in section 110(a)(2)(D)(i) require each state to submit a 
SIP that prohibits emissions that adversely affect another state in the 
ways contemplated in the statute. Section 110(a)(2)(D)(i) contains four 
distinct requirements related to the impacts of interstate transport. 
The SIP must prevent sources in the state from emitting pollutants in 
amounts which will: (1) Contribute significantly to nonattainment of 
the NAAQS in other states; (2) interfere with maintenance of the NAAQS 
in other states; (3) interfere with provisions to prevent significant 
deterioration of air quality in other states; or (4) interfere with 
efforts to protect visibility in other states.
    On September 17, 2007, EPA received a SIP revision from the State 
of New Mexico intended to address the requirements of section 
110(a)(2)(D)(i) for both the 1997 8-hour ozone standards and the 1997 
PM2.5 standards. In this rulemaking, EPA is addressing only 
the requirements that pertain to preventing sources in New Mexico from 
emitting pollutants that will interfere with maintenance of the 1997 8-
hour ozone NAAQS and the 1997 PM2.5 NAAQS in other states, 
or that will interfere with measures required to prevent significant 
deterioration of air quality in other states with respect to these 
NAAQS. In its submission, the State of New Mexico indicated that its 
current SIP is adequate to prevent such interference, and thus argued 
that no additional emissions controls or other revisions are necessary 
at this time to alleviate interstate transport for the 1997 8 hour 
ozone NAAQS or the 1997 PM2.5 NAAQS. With this submission, 
the state would meet the first and second elements of section 
110(a)(2)(D)(i).
    On August 31, 2009, the New Mexico Environment Department (NMED) 
also adopted revisions to its PSD SIP in response to revisions required 
by EPA for the 1997 8-hour ozone NAAQS. EPA received these revisions on 
September 21, 2009. These submitted PSD revisions included changes to 
20.2.74 NMAC (New Mexico Administrative Code) for ``Permits--Prevention 
of Significant Deterioration (PSD)'' necessary to address 
NOX as a precursor for the 1997 8-hour ozone NAAQS. The 
submittal contained revisions to Subsections 20.2.74.7 NMAC, 
Definitions; 20.2.74.502 NMAC, Table 2, Significant Emission Rates 
inclusion of nitrogen oxides rate for ozone; and 20.2.74.503 NMAC, 
Table 3, Significant Monitoring Concentrations, Footnote b, inclusion 
of baseline threshold for nitrogen oxides for requirements in ambient 
impact analysis.
    With EPA's approval of this revision, that includes NOX 
as a precursor of the 1997 8-hour ozone NAAQS, New Mexico's PSD SIP 
will include changes necessary to implement the 1997 8-hour ozone NAAQS 
within the state as contemplated in the 2006 Guidance for SIP 
submissions to meet the third element of section 110(a)(2)(D). The 
submittal also contained revisions to 20.2.2 NMAC, Definitions and 
20.2.79 NMAC, Permits--Nonattainment Areas. At this time, EPA is not 
taking action on these other SIP revisions submitted with the PSD SIP 
revisions.

[[Page 52695]]

IV. What is EPA's evaluation of the State's submission?

A. EPA's Evaluation of Interference With Maintenance

    The second element of section 110(a)(2)(D)(i) requires that a 
state's SIP must prohibit any source or other type of emissions 
activity in the state from emitting pollutants that would ``interfere 
with maintenance'' of the applicable NAAQS in any other state. This 
term is not defined in the statute. Therefore, EPA has interpreted this 
term in past regulatory actions, such as the 1998 NOX SIP 
Call, in which EPA took action to remediate emissions of NOX 
that significantly contributed to nonattainment, or interfered with 
maintenance of, the then applicable ozone NAAQS through interstate 
transport of NOX and the resulting ozone.\2\ The 
NOX SIP Call was the mechanism through which EPA evaluated 
whether or not the NOX emissions from sources in certain 
states had such prohibited interstate impacts, and if they had such 
impacts, required the states to adopt substantive SIP revisions to 
eliminate those NOX emissions, whether through participation 
in a regional cap and trade program or by other means.
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    \2\ See, 63 FR 57356 (October 27, 1998). EPA's general approach 
to section 110(a)(2)(D) was upheld in Michigan v. EPA, 213 F.3d 663 
(DC Cir. 2000), cert denied, 532 U.S. 904 (2001). However, EPA's 
approach to interference with maintenance in the NOX SIP 
Call was not explicitly reviewed by the court. See, North Carolina 
v. EPA, 531 F.3d 896, 907-09 (DC Cir. 2008).
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    After promulgation of the 1997 8-hour ozone NAAQS and the 1997 
PM2.5 NAAQS, EPA again recognized that regional transport 
was a serious concern throughout the eastern U.S. and therefore 
developed the 2005 Clean Air Interstate Rule (CAIR) to address 
emissions of SO2 and NOX that exacerbate ambient 
ozone and PM2.5 levels in many downwind areas through 
interstate transport.\3\ Within CAIR, EPA likewise interpreted the term 
``interfere with maintenance'' as part of the evaluation of whether or 
not the emissions of sources in certain states had such impacts on 
areas that EPA determined would either be in violation of the NAAQS, or 
would be in jeopardy of violating the NAAQS, in a modeled future year 
unless action were taken by upwind states to reduce SO2 and 
NOX emissions. Through CAIR, EPA again required states that 
had such interstate impacts to adopt substantive SIP revisions to 
eliminate the SO2 and NOX emissions, whether 
through participation in a regional cap and trade program or by other 
means.
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    \3\ See, 70 FR 25162 (May 12, 2005).
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    EPA's 2006 Guidance addressed section 110(a)(2)(D) requirements for 
the 1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS. For those 
states subject to CAIR, EPA indicated that compliance with CAIR would 
meet the two requirements of section 110(a)(2)(D)(i)(I) for these 
NAAQS. For states not within the CAIR region, EPA recommended that 
states evaluate whether or not emissions from their sources would 
``interfere with maintenance'' in other states, following the 
conceptual approach adopted by EPA in CAIR. After recommending various 
types of information that could be relevant for the technical analysis 
to support the SIP submission, such as the amount of emissions and 
meteorological conditions in the state, EPA further indicated that it 
would be appropriate for the state to assess impacts of its emissions 
on other states using considerations comparable to those used by EPA 
``in evaluating significant contribution to nonattainment in the 
CAIR.'' \4\ EPA did not make specific recommendations for how states 
should assess ``interfere with maintenance'' separately, and discussed 
the first two elements of section 110(a)(2)(D) together without 
explicitly differentiating between them.
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    \4\ 2006 Guidance at page 5.
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    In 2008, however, the U.S. Court of Appeals for the DC Circuit 
found that CAIR and the related CAIR federal implementation plans were 
unlawful.\5\ Among other issues, the court held that EPA had not 
correctly addressed the second element of section 110(a)(2)(D)(i)(I) in 
CAIR. The court noted that ``EPA gave no independent significance to 
the `interfere with maintenance' prong of section 110(a)(2)(D)(i)(I) to 
separately identify upwind sources interfering with downwind 
maintenance.'' \6\. EPA's approach, the court reasoned, would leave 
areas that are ``barely meeting attainment'' with ``no recourse'' to 
address upwind emissions sources.\7\ The court therefore concluded that 
a plain language reading of the statute requires EPA to give 
independent meaning to the interfere with maintenance requirement of 
section 110(a)(2)(D) and that the approach used by EPA in CAIR failed 
to do so.
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    \5\ See, North Carolina v. EPA, 531 F.3d 896 (DC Circuit 2008).
    \6\ Id. 531, F.3d at 909.
    \7\ Id.
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    In addition to affecting CAIR directly, the court's decision in the 
North Carolina case indirectly affects EPA's recommendations to states 
in the 2006 Guidance with respect to the interfere with maintenance 
element of section 110(a)(2)(D) because the agency's guidance suggested 
that states use an approach comparable to that used by EPA in CAIR. 
States such as New Mexico have already made SIP submissions that rely 
upon the recommendations in EPA's 2006 Guidance, and accordingly may 
not have sufficiently differentiated between the significant 
contribution to nonattainment and interfere with maintenance elements 
of the statute. Given the court decision on CAIR in the interim, 
however, EPA believes that it is necessary to evaluate these state 
submissions for section 110(a)(2)(D) in such a way as to assure that 
the interfere with maintenance element of the statute is given 
independent meaning and is appropriately evaluated using the types of 
information that EPA recommended in the 2006 Guidance. To accomplish 
this, EPA believes it is necessary to use an updated approach to 
address this issue and to supplement the technical analysis provided by 
the state in order to evaluate the submissions with the respect to the 
interfere with maintenance element of section 110(a)(2)(D).
    EPA has recently proposed a new rule to address interstate 
transport pursuant to section 110(a)(2)(D), the ``Federal 
Implementation Plans to Reduce Interstate Transport of Fine Particulate 
Matter and Ozone'' (Transport Rule Proposal), in order to address the 
judicial remand of CAIR.\8\ As part of the Transport Rule Proposal, EPA 
specifically reexamined the section 110(a)(2)(D) requirement that 
emissions from sources in a state must not ``interfere with 
maintenance'' of the 1997 8-hour ozone NAAQS and 1997 PM2.5 
NAAQS in other states. In the proposal, EPA developed an approach to 
identify areas that it predicts to be close to the level of the 1997 8-
hour ozone NAAQS and 1997 PM2.5 NAAQS, and therefore at risk 
to become nonattainment for these NAAQS unless emissions from sources 
in other states are appropriately controlled. This approach starts by 
identifying those specific geographic areas for which further 
evaluation is appropriate, and differentiates between areas where the 
concern is with interference with maintenance, rather than with 
significant contribution to nonattainment.
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    \8\ See ``Federal Implementation Plans to Reduce Interstate 
Transport of Fine Particulate Matter and Ozone,'' 75 FR 45210 
(August 2, 2010).
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    As described in more detail below, EPA's analysis evaluates data 
from

[[Page 52696]]

existing monitors over three overlapping three year periods (i.e., 
2003-2005, 2004-2006, and 2005-2007), as well as air quality modeling 
data, in order to determine which areas are predicted to be violating 
the 1997 ozone and PM2.5 NAAQS in 2012, and which areas are 
predicted to potentially have a difficulty with maintaining attainment 
as of that date. In essence, if an area's projected data for 2012 
indicates that it would be violating the NAAQS based on the average of 
these three overlapping periods, then this monitor location is 
appropriate for comparison for purposes of the significant contribution 
to nonattainment element of section 110(a)(2)(D). If, however, an 
area's projected data indicate that it would be violating the NAAQS 
based on the highest single period, but not over the average of the 
three periods, then this monitor location is appropriate for comparison 
for purposes of the interfere with maintenance element of the 
statute.\9\
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    \9\ A memorandum in the docket for this action provides the 
information EPA used in order to identify monitors that are 
receptors for evaluation of interference with maintenance for 
certain states in the western United States. See, Memorandum from 
Brian Timin of EPA's Office of Air Quality Planning and Standards, 
Air Quality Modeling Group entitled ``Documentation of Future Year 
Ozone and Annual PM2.5 Design Values for Western States'' 
(August 2010) (Timin Memo).
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    By this method, EPA has identified those areas with monitors that 
are appropriate ``maintenance sites'' or maintenance ``receptors'' for 
evaluating whether the emissions from sources in another state could 
interfere with maintenance in that particular area. EPA then uses other 
analytical tools to examine the potential impacts of emissions from 
upwind states on these maintenance sites in downwind states. EPA 
believes that this new approach for identifying those areas that are 
predicted to have maintenance problems is appropriate to evaluate the 
section 110(a)(2)(D) SIP submission of a state for the interfere with 
maintenance element.\10\ EPA's 2006 Guidance did not provide this 
specific recommendation to states, but in light of the court's decision 
on CAIR, EPA will itself follow this approach in acting upon the New 
Mexico submission.
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    \10\ To begin this analysis, EPA first identifies all monitors 
projected to be in nonattainment or, based on historic variability 
in air quality, projected to have maintenance problems in 2012. The 
``problem'' is that these maintenance areas are at risk not to stay 
in attainment because they are so close to the level of the 1997 
ozone and PM2.5 NAAQS that minor variations in weather or 
emissions could result in violations of the NAAQS in 2012.
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    As explained in the 2006 Guidance, EPA does not believe that 
section 110(a)(2)(D) SIP submissions from all states necessarily need 
to follow precisely the same analytical approach of CAIR. In the 2006 
Guidance, EPA stated that: ``EPA believes that the contents of the SIP 
submission required by section 110(a)(2)(D) may vary, depending upon 
the facts and circumstances related to the specific NAAQS. In 
particular, the data and analytical tools available at the time the 
State develops and submits a SIP for a new or revised NAAQS necessarily 
affects the contents of the required submission.'' \11\ EPA also 
indicated in the 2006 Guidance that it did not anticipate that sources 
in states outside the geographic area covered by CAIR were 
significantly contributing to nonattainment, or interfering with 
maintenance, in other states.\12\ As noted in the Transport Rule 
Proposal, EPA continues to believe that the more widespread and serious 
transport problems in the eastern United States are analytically 
distinct.\13\ For the 1997 8-hour ozone NAAQS and the 1997 
PM2.5 NAAQS, EPA believes that nonattainment and maintenance 
problems in the western United States are relatively local in nature 
with only limited impacts from interstate transport. In the Transport 
Rule Proposal, EPA did not calculate interstate ozone or 
PM2.5 contributions to or from Western States.
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    \11\ 2006 Guidance at 4.
    \12\ Id. at 5.
    \13\ See, Transport Rule Proposal, 75 FR 45210 (August 2, 2010) 
at page 45227.
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    Accordingly, EPA believes that section 110(a)(2)(D) SIP submissions 
for states outside the geographic area of the Transport Rule Proposal 
may be evaluated using a ``weight of the evidence'' approach that takes 
into account the available relevant information, such as that 
recommended by EPA in the 2006 Guidance for states outside the area 
affected by CAIR. Such information may include, but is not limited to, 
the amount of emissions in the state relevant to the NAAQS in question, 
the meteorological conditions in the area, the distance from the state 
to the nearest monitors in other states that are appropriate receptors, 
or such other information as may be probative to consider whether 
sources in the state may interfere with maintenance of the 1997 8-hour 
ozone NAAQS and 1997 PM2.5 NAAQS in other states. These 
submissions can rely on modeling when acceptable modeling technical 
analyses are available, but EPA does not believe that modeling is 
necessarily required if other available information is sufficient to 
evaluate the presence or degree of interstate transport in a given 
situation.

B. New Mexico Transport SIP

    To meet the requirements of section 110(a)(2)(D), the State of New 
Mexico made a SIP submission to address interstate transport for the 
1997 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS. EPA has 
previously approved this submission for purposes of the significant 
contribution to nonattainment element of section 110(a)(2)(D).\14\ 
Below, we discuss our evaluation of the state's submission with respect 
to the interference with maintenance element and the interference with 
measures required to prevent significant deterioration of air quality 
element.
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    \14\ See, 75 FR 33174 (June 11, 2010).
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a. Interference With Maintenance
    The State's submittal focused primarily on whether emissions from 
New Mexico sources significantly contribute to nonattainment of the 
1997 8-hour ozone NAAQS and 1997 PM2.5 NAAQS in other 
states. Following the 2006 Guidance and consistent with EPA's approach 
in CAIR, New Mexico did not evaluate whether emissions from New Mexico 
sources interfere with maintenance of these NAAQS in other states 
separately from significant contribution to nonattainment in other 
states. Instead, the state presumed that if New Mexico sources were not 
significantly contributing to violations of the NAAQS in other states, 
then no further specific evaluation was necessary for purposes of the 
interfere with maintenance element of section 110(a)(2)(D). As 
explained above, however, CAIR was remanded to EPA, in part because the 
court found that EPA had not correctly addressed whether emissions from 
sources in a state interfere with maintenance of the standards in other 
states. Therefore, EPA must evaluate the New Mexico submission in light 
of the decision of the court.
    On July 6, 2010, the EPA Administrator signed a proposed rule in 
response to the judicial remand of CAIR. The Transport Rule Proposal 
includes a new approach to determine whether emissions from a state 
interfere with maintenance of the 1997 8-hour ozone NAAQS and the 1997 
PM2.5 NAAQS in other states. EPA is using a comparable 
approach to that of the Transport Rule Proposal in this action in order 
to determine if emissions from New Mexico sources interfere with 
maintenance of these NAAQS in other states.
    In the Transport Rule Proposal, EPA projected future concentrations 
of ozone

[[Page 52697]]

and PM2.5 to identify areas that are expected to be out of 
attainment with NAAQS or to have difficulty maintaining compliance with 
the NAAQS in 2012. These areas are referred to as nonattainment and 
maintenance receptors, respectively. These nonattainment and 
maintenance receptors are based on projections of future air quality at 
existing ozone and PM2.5 monitoring sites in those 
locations. EPA then used these sites as the receptors for examining the 
contributions of emissions from sources located in upwind states to 
nonattainment and maintenance problems at these monitoring locations. 
Monitoring data was obtained from EPA's Air Quality System (AQS).
    For ozone, EPA evaluated concentrations relevant to the 1997 8-hour 
ozone NAAQS. The level of the 1997 8-hour ozone NAAQS is 0.08 parts per 
million (ppm). The 8-hour ozone standard is met if the 3-year average 
of the annual 4th highest daily maximum 8-hour ozone concentration is 
less than or equal to 0.08 ppm (i.e., less than 0.085 ppm based on the 
rounding convention in 40 CFR part 50 Appendix I). This 3-year average 
is referred to as the ``design value.''
    For PM2.5, EPA evaluated concentrations of both the 
annual PM2.5 NAAQS and the 24-hour PM2.5 NAAQS. 
The 1997 annual PM2.5 NAAQS is met when the 3-year average 
of the annual mean concentration is 15.0 micrograms per cubic meter 
([mu]g/m\3\) or less. The 3-year average annual mean concentration is 
computed at each site by averaging the daily Federal Reference Method 
(FRM) samples by quarter, averaging these quarterly averages to obtain 
an annual average, and then averaging the three annual averages to get 
the design value. The 2006 24-hour PM2.5 NAAQS is met when 
the 3-year average of the annual 98th percentile PM2.5 
concentrations is 35 [mu]g/m\3\ or less. The 1997 24-hour 
PM2.5 NAAQS is met when the 3-year average of the annual 
98th percentiles is 65 [mu]g/m\3\ or less. The 3-year average mean 98th 
percentile concentration is computed at each site by averaging the 3 
individual annual 98th percentile values at each site. The 3-year 
average 98th percentile concentration is referred to as the 24-hour 
average design value. In this action, EPA is only evaluating whether 
New Mexico's emissions impact other states' ability to maintain the 
1997 annual and 24-hour PM2.5 NAAQS and the 1997 8-hour 
ozone NAAQS, because those are the NAAQS at issue in this section 
110(a)(2)(D) SIP submission. In later actions, the state and EPA will 
evaluate the impacts of interstate transport from emissions from New 
Mexico sources with respect to other NAAQS.
    To project future ozone and annual PM2.5 design values, 
EPA projected future ozone values based on an average of three design 
value periods which include the years 2003-2007 (i.e., design values 
for 2003-2005, 2004-2006, and 2005-2007). The average of the three 
design values creates a ``5-year weighted average'' value. The 5-year 
weighted average values were then projected to the future years that 
were analyzed for the Transport Rule Proposal.15 16 EPA used 
the 5-year weighted average concentrations to project concentrations 
anticipated in 2012 to determine which monitoring sites are expected to 
be nonattainment in this future year. EPA also projected 2012 design 
values based on each of the three-year periods (i.e., 2003-2005, 2004-
2006, and 2005-2007). The highest projection is referred to as the 
``maximum design value'' and gives an indication of potential 
variability in future projections due to differences in actual 
meteorology and emissions from what was modeled.
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    \15\ See, the Transport Rule Proposal at 75 FR 45210 (August 2, 
2010).
    \16\ Additional information concerning these weighted averages 
is provided in the docket in the Timin Memo.
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    EPA identified those sites that are projected to be attainment 
based on the 5-year weighted average design value, but that have a 
maximum design value (based on a single three-year period) that exceeds 
the NAAQS, as maintenance sites because EPA anticipates that there will 
be more difficulty in maintaining attainment of the NAAQS at these 
locations if there are adverse variations in meteorology or emissions. 
These projected maintenance sites are the ones that EPA has used to 
determine if emissions from New Mexico sources potentially interfere 
with maintenance of the 1997 8-hour ozone NAAQS and 1997 annual 
PM2.5 NAAQS in other states in this action.
    From the modeling analyses conducted for the Transport Rule 
Proposal, EPA identified the following maintenance sites or receptors 
for the 1997 8-hour ozone NAAQS: Several sites in the Dallas-Ft.Worth 
(DFW) area; several sites in the Houston/Galveston/Brazoria (Houston) 
area; and other more distant sites in Georgia, Pennsylvania, New York 
and Connecticut.\17\ For assessing New Mexico's potential for impacts 
on maintenance receptors, the DFW and Houston areas seem to have the 
highest probability of potential impact from New Mexico emissions. For 
the modeling analysis conducted for states not included in the 
Transport Rule Proposal (i.e., states not included fully in the 12 km 
Transport Rule Proposal modeling domain), EPA identified several 
maintenance sites for the 1997 8-hour ozone NAAQS in southern and 
central California using available 36 km modeling.\18\ The 12 km 
Transport Rule Proposal modeling domain extends from Texas northward to 
North Dakota and eastward from the Rocky Mountains to the East Coast 
and includes 37 states and the District of Columbia. Significantly, 
EPA's analysis did not identify any monitor sites in the states that 
border New Mexico (Texas, Arizona, Colorado, Utah, and Oklahoma), other 
than the noted Texas areas, as maintenance sites in the Transport Rule 
Proposal.
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    \17\ Transport Rule Proposal, 75 FR 45210, (August 2, 2010), 
pages 45253-45270, and Timin Memo.
    \18\ The Transport Rule Proposal identifies nonattainment and 
maintenance receptors in the Eastern U.S. It does not include 
modeling results for the West. The Timin Memo documents further 
evaluation of the 2012 modeling to identify nonattainment and 
maintenance receptors in the West.
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    For the annual PM2.5 NAAQS, EPA identified the following 
sites as maintenance receptors: A site in Cook County, Illinois in the 
Chicago area; a site in Harris County, Texas, in the Houston/Galveston/
Brazoria area; and two sites in southern California. As part of the 
Transport Rule Proposal, EPA did not evaluate nonattainment receptors 
for the 1997 24-hour PM2.5 NAAQS because there were no 
violations of the standard in portions of the U.S. covered by the 12 km 
grid, which consists of the continental U.S. east of the Rockies.\19\ 
In fact, based on recent monitoring data (2007-2009 design values that 
are under final EPA review), the highest 24-hour PM2.5 
design value in the 47 states of the continental U.S. (not including 
California) is 50 [mu]g/m\3\, which is well below the level of the 1997 
24-hour PM2.5 NAAQS of 65 [mu]g/m\3\.\20\ Therefore, outside 
of California, there are no areas that we would expect to have 
difficulty in maintaining the 1997 24-hour PM2.5 NAAQS. We 
address the potential for interference with maintenance in California 
for the 1997 24-hour PM2.5 NAAQS later in this notice.
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    \19\ Id., EPA did not calculate model projections for the 24-
hour PM2.5 NAAQS in the 36km modeling domain.
    \20\ Data undergoing review from EPA's Air Quality System which 
is EPA's repository of ambient air quality data. (https://www.epa.gov/ttn/airs/airsaqs/).
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    EPA has evaluated available analyses and conducted additional 
analyses for each of these identified maintenance sites that may be 
potentially impacted by emissions from sources in New Mexico. Using the 
same proposed

[[Page 52698]]

screening thresholds for analyzing a state's impacts on another state's 
maintenance sites that are used in the Transport Rule Proposal, we have 
determined that emissions from New Mexico do not have a large enough 
impact on any of these identified maintenance sites to interfere with 
maintenance.\21\ For the reasons discussed below, EPA has determined 
that emissions from New Mexico do not interfere with maintenance of 
these NAAQS in any other state.
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    \21\ Transport Rule Proposal, 75 FR 45210 (August 2, 2010), 
pages 45253-45270. The Transport Rule Proposal included proposed 
screening thresholds, using 1% of the NAAQS, for determining if a 
State should be evaluated for emission reductions from the Transport 
Rule. The proposed thresholds were 0.15 [mu]g/m\3\ or more 
contribution to annual PM2.5, 0.35 [mu]g/m\3\ or more 
contribution to the 1997 24-hour PM2.5 NAAQS, and 0.8 ppb 
or more contribution to the 1997 8-hour ozone NAAQS for States which 
contribute to nonattainment or maintenance sites in another state. 
In this notice, we are using the same 1% contribution thresholds in 
this notice of 0.15 [mu]g/m\3\ for the annual PM2.5 
NAAQS, 0.8 ppb or more for the 1997 8-hour ozone NAAQS. We are 
proposing a similar 1% threshold of 0.65 [mu]g/m\3\ or more for the 
1997 24-hour PM2.5 NAAQS.
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Ozone Interfere With Maintenance Evaluation
    EPA evaluated whether emissions from sources in New Mexico could 
interfere with maintenance of the 1997 8-hour ozone NAAQS in other 
states by considering the potential impacts of such sources on 
projected maintenance sites in California, Texas, and points much 
further to the east. As discussed in more detail in the Technical 
Support Document (TSD) for this action, EPA concluded that such impacts 
were most likely to be from New Mexico sources to the Houston and DFW 
areas and that even those impacts are very small and below the level 
EPA considered the initial threshold for further evaluation in the 
Transport Rule Proposal.
    EPA did not separately determine the impacts of New Mexico's 
emissions on other States as part of the Transport Rule Proposal 
analysis because New Mexico was partially outside the 12 kilometer 
grid. Other modeling was available to evaluate the impact of New 
Mexico's emissions on the 8-hour ozone maintenance sites that EPA 
identified in the Houston and DFW areas. EPA has conducted a modeling 
estimate of impacts from New Mexico's emissions using the Central 
Regional Air Planning Association (CENRAP) modeling of 2002 emissions 
and meteorology.\22\ The CENRAP modeling that EPA utilized was an 
earlier version of the CENRAP modeling that a number of states 
submitted as part of their Regional Haze State Implementation Plan 
submittals and is currently being reviewed by EPA. EPA's source 
apportionment CENRAP modeling for the 8-hour ozone NAAQS was conducted 
in 2006 to help provide New Mexico and other states with a technical 
analysis for the 110(a)(2)(D) SIP submissions.
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    \22\ Appendix G of New Mexico's SIP submittal for 
110(a)(2)(d)(i), ``110(a)(2)(d)(i) Modeling Technical Support 
Document''.
---------------------------------------------------------------------------

    As discussed above, the CENRAP modeling evaluated New Mexico's 
impact based on emission and meteorological conditions in 2002. For the 
reasons discussed below, EPA believes that this modeling is in fact a 
more conservative approach to evaluate the potential for impacts on 
other states since it uses a 2002 inventory rather than a 2010 or 2012 
emission inventory. The 2002 analysis would include more emissions 
within the modeling domain because of decrease in emissions after 2002 
due to federal measures (such as fleet turnover and cleaner vehicles) 
and local reductions in DFW, Houston, and other parts of the modeling 
grid.
    As mentioned previously, the evaluation was based on an earlier 
version of the model. Source apportionment results are not available 
for the final version of the model. If results were available, we do 
not expect them to be significantly different than the earlier version 
and any differences would be more than offset by the conservative 
nature of using the 2002 emissions.
    EPA analyzed source apportionment modeling with the 2002 based 
CENRAP modeling and concluded that maximum impacts from the emissions 
of New Mexico sources would be 0.2% of the NAAQS in the Dallas/Ft. 
Worth area and 0.4% of the NAAQS in the Houston area, which are less 
than the one percent of the NAAQS screening threshold (0.8 parts per 
billion) which EPA used in the Transport Rule Proposal to identify 
states for further analysis and the threshold that we are proposing for 
our determination. The methodology EPA used in the Transport Rule 
Proposal to determine if a state's emissions exceeded the one percent 
of the NAAQS considered the average impact of a state on a downwind 
monitoring site in another state. Comparing the maximum impacts shown 
by the CENRAP modeling to the Transport Rule Proposal screening 
threshold is a conservative approach, because the average impact over 
all exceedance days at sites in DFW or Houston would be lower. 
Furthermore, EPA considers the CENRAP modeling analysis conservative 
because it relies on 2002 emission inventory levels, whereas additional 
emission reductions have occurred in New Mexico and throughout the 
modeling domain due to fleet turnover and other measures to reduce air 
pollution between 2002 and 2010 that would result in lower overall 
pollution levels if taken into account. EPA believes that using the 
existing CENRAP analysis provides a conservative basis for concluding 
that emissions from New Mexico do not have a substantial impact at 1997 
8-hour ozone NAAQS maintenance receptors outside the state.
    In addition, EPA has reviewed other available information 
concerning the cause of higher ozone concentration levels in the DFW 
and Houston areas, and this further confirms that when these two areas 
experience elevated ozone levels, the meteorological patterns only 
rarely trace the origins of these air masses to the New Mexico 
area.\23\ Because available evidence indicates that New Mexico 
emissions are not impacting ozone levels in the DFW and Houston areas 
to a degree that constitutes interference with maintenance, it is 
improbable that New Mexico emissions would have such impacts at other 
identified maintenance sites much farther to the east. EPA believes 
that the only other identified maintenance sites for 1997 8-hour ozone 
NAAQS that might be impacted by New Mexico sources are in southern and 
central California. As further discussed in the TSD for this notice, 
however, EPA has concluded that the meteorological patterns (e.g., 
prevailing winds and meteorology that occur when ozone exceedances 
occur) do not transport emissions from New Mexico to California when 
California has elevated ozone levels, and that the relatively long 
distance and the intervening mountainous topography further support 
this conclusion.
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    \23\ Further details are included in the Modeling TSD Memorandum 
for this notice.
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PM2.5 Interfere With Maintenance Evaluation
    EPA evaluated whether emissions from sources in New Mexico could 
interfere with maintenance in other states by considering the potential 
impacts of such sources on projected maintenance receptors in Illinois, 
California, and Texas. As discussed in more detail in the TSD for this 
action, EPA concluded that such impacts were most likely to be from New 
Mexico sources to the Houston area, and that those impacts are shown to 
be very small.
    For the 1997 annual PM2.5 NAAQS site located in the 
Chicago area, previous EPA modeling developed for the 2004 CAIR 
proposal indicated that

[[Page 52699]]

impacts from New Mexico's emissions was 0.02 [mu]g/m\3\,\24\ which is 
well below the one percent of the NAAQS (i.e., (0.15 [mu]g/m\3\)) 
threshold that EPA has proposed as the initial threshold for 
interference with maintenance in the Transport Rule Proposal for the 
1997 annual PM2.5 NAAQS. The CAIR proposal modeling used a 
2010 future year assessment versus the 2012 year used in the Transport 
Rule Proposal, but EPA believes that the emissions would be similar and 
that the 2010 analysis would actually have included somewhat more 
emissions within the modeling domain because it included two fewer 
years of reductions from federal measures (e.g., fleet turnover). In 
summary, the results of analysis using 2010 would be expected to be 
similar to but slightly more conservative than would be expected for 
2012. Therefore, we believe the 2004 CAIR modeling adequately 
demonstrates that New Mexico's emissions do not interfere with 
maintenance in the Chicago area.
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    \24\ EPA's ``Technical Support Document for the Interstate Air 
Quality Rule Air Quality Modeling Analyses Appendix H, 
PM2.5 Contributions to Downwind Nonattainment Counties in 
2010'', January 2004.
---------------------------------------------------------------------------

    EPA did not separately calculate the impact of New Mexico's 
emissions on the Houston area as part of the CAIR modeling or in the 
Transport Rule Proposal modeling, but EPA believes that one can infer 
from New Mexico's extremely small impact on other areas that New 
Mexico's impact on the Houston area would also be less than one percent 
of the NAAQS. The only modeling available that provided source 
apportionment for annual PM2.5 values is the CAIR proposal 
modeling. The CAIR source apportionment results that would be expected 
to most closely match Houston from a transport phenomena perspective 
are the results for potential impacts on St. Louis. St. Louis is 
helpful for comparison because, while not the same direction from New 
Mexico it is the closest area evaluated in the CAIR proposal modeling 
that is to the east (in the same general transport direction) and at a 
similar distance from New Mexico as Houston.
    For the St. Louis area, the CAIR proposal modeling indicated that a 
maximum impact from New Mexico's emissions of 0.02 [mu]g/m\3\, which is 
well below the 1% of the NAAQS screening threshold. The majority of the 
emissions of PM2.5 and PM2.5 precursors from New 
Mexico sources emanate from either the Albuquerque area or from points 
father west, so it is a useful point from which to evaluate the 
relative distances, The distance from Albuquerque to St. Louis, 
Missouri is approximately 920 miles and the distance from Albuquerque 
to Houston is about 750 miles, which is about 81.5% of the distance 
from Albuquerque to St. Louis.\25\ Even if one conservatively assumed 
that New Mexico emissions had twice the impact on Houston that EPA 
determined they do on St Louis due to the shorter transport distances, 
New Mexico's impact on Houston would still be significantly below the 
1% of the NAAQS threshold in the Transport Proposal. Given that the 
difference in distances is only 18.5%, this is a conservative analysis 
that would indicate no significant impacts would be expected from New 
Mexico on sites in Houston, Texas.
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    \25\ TSD. EPA believes that such a comparison is instructive 
because the majority of relevant New Mexico emissions occur from 
sources or activities located in the Albuquerque metropolitan area, 
or in areas further to the west. Even if measured from the New 
Mexico state border to St. Louis and Houston, however, the 
proportional impact would presumably be comparable.
---------------------------------------------------------------------------

    Also, the relative amounts of emissions in New Mexico, when 
compared to the emissions in Texas, support the conclusion that New 
Mexico emissions do not interfere with maintenance in areas in Texas. 
Using databases developed in connection with the Regional Haze (RH) 
program and submitted with the RH SIPs, the Texas emissions of 
SO2 are approximately 18 times larger than New Mexico's, the 
NOX emissions are approximately 5 times greater than New 
Mexico's, the fine particulate matter emissions are 12 times greater 
than New Mexico's and the coarse particulate matter is 5.6 times 
greater than New Mexico's emissions. The Transport Rule Proposal 
modeling information also includes emission summaries that indicate 
that Texas's emissions are 1,338,429 tpy of NOX and 639,505 
tpy of SO2 whereas New Mexico's emissions are 240,892 tpy of 
NOX and 24,930 tpy of SO2. Both sets of data 
indicate that New Mexico's emissions are much lower than Texas's 
emissions of PM2.5 precursors. Moreover, most of the sources 
of PM2.5 precursor emissions in Texas are much closer to the 
maintenance receptor in Houston, and therefore less dispersion of the 
pollutants occurs, so Texas's own PM2.5 and PM2.5 
precursors will have a much larger impact on PM2.5 levels in 
Houston.
    In addition, the Texas Commission on Environmental Quality (TCEQ) 
and several researchers have conducted research into the likely causes 
of elevated annual and 24-hour PM2.5 monitoring values in 
the Houston area. TCEQ and the researcher's analyses do not indicate 
that emissions from New Mexico impact Houston to a degree to raise a 
concern for purposes of the 1997 PM2.5 NAAQS. These analyses 
indicate that meteorological patterns are transporting air masses from 
other directions (i.e., not from the direction of New Mexico) when 
Houston area sites are monitoring elevated PM2.5 levels that 
have the greatest impact on the annual DV.\26\ As discussed further in 
the TSD, distance between the emission sources and the maintenance 
receptors and meteorological patterns during times of elevated 
pollution levels in Chicago and Houston also support the conclusion 
that New Mexico's emissions do not interfere with maintenance of the 
NAAQS in these areas. In summary, considering the available evidence, 
EPA concludes that New Mexico's emissions do not interfere with 
maintenance of the 1997 PM2.5 NAAQS in Houston area.
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    \26\ ``Source Apportionment for PM2.5 at Houston 
Clinton Drive'', David W. Sullivan, as The University of Texas at 
Austin Center for Energy & Environmental Research and Richard Tropp, 
University of Nevada Reno Desert Research Institute, TEXAQS II 
Workshop May 29, 2007 and TCEQ Fact Sheet ``Harris County/Clinton 
Drive 1997 Annual Fine Particulate Matter (PM2.5)'' 
November 2009.
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    EPA also reviewed the potential for emissions from New Mexico 
sources to impact other areas with identified maintenance sites. The 
other such areas are located in California. As further discussed in the 
TSD, EPA concludes that New Mexico sources are unlikely to have such 
impacts given the geographic location of these areas and the 
meteorological patterns that prevail in the western United States. With 
respect to the 1997 PM2.5 24-hour standard of 65 [mu]g/m\3\, 
the other identified maintenance sites that New Mexico sources might 
impact are located in California. EPA has evaluated conceptual model 
documents and field study reports that indicate that transport patterns 
when elevated PM2.5 occurs in areas of California, the 
meteorological patterns are not such that transport of emissions from 
New Mexico to California is occurring to a degree to raise a 
concern.\27\ EPA believes that it is rare for meteorological patterns 
to occur that would transport emissions from New Mexico sources in such 
a way that they would impact California's pollution levels, and that 
the relatively long distance and the intervening mountainous topography 
further support that transport of emissions from New Mexico is 
unlikely. Therefore,

[[Page 52700]]

available information indicates that emissions from sources in New 
Mexico do not impact areas of concern in California to the degree that 
would interfere with maintenance of the 1997 NAAQS in those areas.
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    \27\ ``Historical Meteorological Analysis in Support of the 2003 
San Joaquin Valley PM10 State Implementation Plan'', 
Shawn R. Ferreria, Air Quality Meteorologist/Atmospheric Scientist 
And Evan M. Shipp, Supervising Air Quality Meteorologist San Joaquin 
Valley Air Pollution Control District January 24, 2005.
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b. Interference With PSD Measures in Other States
    The third element of section 110(a)(2)(D)(i) requires a SIP to 
contain adequate provisions prohibiting emissions that interfere with 
any other state's required measures to prevent significant 
deterioration of its air quality. EPA's 2006 Guidance made 
recommendations for SIP submissions to meet this requirement with 
respect to both the 1997 8-hour ozone NAAQS and the 1997 
PM2.5 NAAQS.
    EPA believes that New Mexico's submission is consistent with the 
2006 Guidance, when considered in conjunction with other PSD program 
revisions that EPA is proposing to approve in this action. The State's 
submittal indicates in Section C, ``Impact on Prevention of Significant 
Deterioration (PSD),'' that the State's SIP provisions include an EPA-
approved PSD program applicable to all regulated pollutants. New 
Mexico's regulations for its PSD program were approved by EPA and made 
part of the SIP on February 27, 1987 (52 FR 5694) at 52.1620/
52.1640(c)(37), effective March 30, 1987. On September 5, 2007, EPA 
approved the New Mexico's PSD revisions incorporating EPA's December 
31, 2002, NSR Reforms into the State's regulations (72 FR 50879), which 
also recognized volatile organic compounds as a precursor for ozone.
    Consistent with EPA's November 29, 2005, Phase 2 rule for the 1997 
8-hour ozone NAAQS (70 FR 71612), the State submitted a SIP revision to 
modify its PSD provisions to address NOX as an ozone 
precursor (20.2.74 NMAC). These revisions are further discussed below. 
EPA believes that the PSD revision for the 1997 8-hour ozone NAAQS that 
make NOX a precursor for ozone for PSD purposes, taken 
together with the PSD SIP and the interstate transport SIP, satisfies 
the requirements of the third element of section 110(a)(2)(D)(i) for 
the 1997 8-hour ozone NAAQS, i.e., there will be no interference with 
any other state's required PSD measures.
    For the PM2.5 NAAQS, New Mexico stated in its section 
110(a)(2)(D)(i) submission that the State would follow EPA's interim 
guidance on use of PM10 as a surrogate for PM2.5 
as recommended in the 2006 Guidance. The New Mexico Environment 
Department (NMED) clarified its interpretation of the New Mexico 
Interstate Transport SIP for Implementation of the PM2.5 
NAAQS in a July 23, 2010 letter to EPA. In the letter NMED stated that: 
(1) It does not use PM10 as a surrogate for PM2.5 
in its permitting programs, (2) it requires that applicants include 
PM2.5 modeling and emissions in their PSD and minor source 
permit applications, and (3) the record for the Department's permitting 
decision includes an explanation of how PM2.5 emissions have 
been appropriately analyzed and estimated. The NMED letter is included 
in the electronic docket for this action. Because of clarifications to 
EPA guidance, EPA believes that New Mexico's approach is appropriate.
    On the basis of the data and analysis presented above, EPA is 
proposing to determine that the New Mexico SIP as revised with respect 
to PSD program requirements, satisfactorily addresses the requirements 
of elements (2) and (3) of section 110(a)(2)(D)(i) for the 1997 8-hour 
ozone NAAQS and 1997 PM2.5 NAAQS.

C. New Mexico PSD SIP

    The New Mexico Environment Department (NMED) made a SIP submission 
to meet requirements of the 8-hour ozone NAAQS by incorporating 
NOX as a precursor for ozone. The submitted PSD SIP 
revisions adding NOX as a precursor for ozone include the 
following:
     The definition of ``Major stationary source'' states that 
a major source that is major for NOX is considered major for 
ozone (20.2.74.7.AF.(4) NMAC);
     The definition of ``Regulated new source review 
pollutant'' specifically identifies NOX as an ozone 
precursor (20.2.74.7.AR.(1) NMAC);
     When referring to a net emissions increase or potential to 
emit, a rate of emissions that equals or exceeds 40 tons per year of 
NOX is significant (20.2.74.502 NMAC, Table 2, Significant 
Emission Rates); and
     Any net emissions increase of 100 tons per year of 
NOX subject to PSD would require an ambient impact analysis, 
including the gathering of ambient air quality data (20.2.74.503 NMAC, 
Table 3, Footnote b).
    For the 8-hour ozone NAAQS, the revision to 20.2.74.7.AF meets the 
federal definition in 40 CFR 51.166(b)(1) to identify a major source of 
nitrogen oxides as a major source for ozone. The revision to 
20.2.74.7.AR NMAC meets the federal definition in 40 CFR 51.166(b)(49) 
for NOX as an ozone precursor. The revision to 20.2.74.502 
NMAC Table 2 meets the federal requirement for significant emission 
rate for NOX emissions in 40 CFR 51.166(b)(23)(i). The 
revision to 20.2.74.503 NMAC, Table 3 meets the federal requirement for 
ambient air impact analysis for ozone precursors under the footnote for 
40 CFR 166(i)(5)(i)(e). Thus, EPA is proposing approval of these 
revisions as meeting the requirements of CAA section 110 and 40 CFR 
51.166 for establishing NOX emissions as a precursor for 
ozone.
    The State's SIP submittal also contains revisions to Parts 20.2.2 
NMAC, Definitions; and 20.2.79 NMAC, Permits--Nonattainment areas. 
These two submitted revisions are severable from each other, are 
severable from the submitted revisions to 20.2.74 NMAC discussed above, 
and are severable from the Transport SIP requirements addressed in this 
proposed action. The EPA is still reviewing the approvability of the 
submitted revisions to Parts 20.2.2 NMAC and 20.2.79 NMAC; therefore, 
we are not proposing to take action on those revisions in this proposed 
rulemaking. We i