Document ID: EPA-R06-OAR-2010-0846-0001
Agency: epa
Document Type: Proposed Rule
Title: NM041.001a Approvals and Promulgations of Implementation Plans: New Mexico; Federal Implementation Plan for Interstate Transport of Pollution Affecting Visibility and Best Available Retrofit Technology Determination -- Comment period extended to April 4, 2011
Posted Date: 2011-01-05T05:00Z

[Federal Register Volume 76, Number 3 (Wednesday, January 5, 2011)]
[Proposed Rules]
[Pages 491-507]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-33106]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2010-0846; FRL-9246-8]

Approval and Promulgation of Implementation Plans; New Mexico; 
Federal Implementation Plan for Interstate Transport of Pollution 
Affecting Visibility and Best Available Retrofit Technology 
Determination

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to disapprove a portion of the State 
Implementation Plan (SIP) revision submitted by the State of New Mexico 
for the purpose of addressing the ``good neighbor'' requirements of 
section 110(a)(2)(D)(i) of the Clean Air Act (CAA or Act) for the 1997 
8-hour ozone National Ambient Air Quality Standards (NAAQS or 
standards) and the 1997 fine particulate matter (PM2.5) 
NAAQS. The SIP revision addresses the requirement that New Mexico's SIP 
must have adequate provisions to prohibit emissions from adversely 
affecting another state's air quality through interstate transport. In 
this action, EPA is proposing to disapprove the New Mexico Interstate 
Transport SIP provisions 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 protect visibility. In this action, EPA is also 
proposing to promulgate a Federal Implementation Plan (FIP) to prevent 
emissions from New Mexico sources from interfering with other states' 
measures to protect

[[Page 492]]

visibility, and to implement nitrogen oxides (NOX) and 
sulfur dioxide (SO2) emission limits necessary at one source 
to prevent such interference. In addition, EPA is proposing sulfuric 
acid (H2SO4) and ammonia (NH3) hourly 
emission limits at the same source, to minimize the contribution of 
these compounds to visibility impairment. EPA is proposing monitoring, 
recordkeeping and reporting requirements to ensure compliance with such 
emission limitations. EPA also proposes that compliance with the 
emission limits be within three (3) years of the effective date of our 
final rule. Furthermore, EPA is proposing the FIP to address the 
requirement for best available retrofit technology (BART) for 
NOX for this source. This action is being taken under 
section 110 and part C of the CAA.

DATES: Comments. Comments must be received on or before March 7, 2011.
    Public Hearing. EPA intends to hold a public hearing in Farmington, 
New Mexico to accept oral and written comments on the proposed 
rulemaking. EPA will provide notice and additional details at least 30 
days prior to the hearing in the Federal Register.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2010-0846, by one of the following methods:
     Federal e-Rulemaking Portal: http://www.regulations.gov.
     Follow the online instructions for submitting comments.
     EPA Region 6 ``Contact Us'' Web site: http://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-2010-
0846. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
http://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 http://www.regulations.gov or e-mail. The http://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 http://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 http://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 http://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, 1301 Siler Road, Building B, Santa Fe, 
New Mexico 87507.

FOR FURTHER INFORMATION CONTACT: Joe Kordzi, Air Planning Section (6PD-
L), Environmental Protection Agency, Region 6, 1445 Ross Avenue, Suite 
700, Dallas, Texas 75202-2733, telephone (214) 665-7186, fax number 
(214) 665-7263; e-mail address kordzi.joe@epa.gov.

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

Outline

I. Overview of Proposed Action
II. Background
    A. SIP and FIP Background
    B. Statutory and Regulatory Framework Addressing Interstate 
Transport and Visibility
    1. The 1997 NAAQS for Ozone and PM2.5 and CAA 
110(a)(2)(D)(i)
    2. Visibility Protection
    3. Best Available Retrofit Technology
    4. The Western Regional Air Partnership and Evaluation of 
Regional Haze Impacts
III. Our Evaluation
    A. New Mexico's Interstate Transport
    B. Federal Implementation Plan To Address Interstate Transport 
and Visibility and the BART Requirements for NOX
    1. Additional SO2 Emission Limits for the SJGS
    2. Need for Additional NOX Controls
    3. NOX BART Evaluation
    a. The SJGS Is a BART Eligible Source
    b. The SJGS Is Subject to BART
    c. The SJGS NOX BART Determination
IV. Proposed Action
V. Statutory and Executive Order Reviews

I. Overview of Proposed Action

    We are proposing to disapprove a portion of the SIP revision 
submitted by the State of New Mexico for the purpose of addressing the 
``good neighbor'' provisions of the CAA section 110(a)(2)(D)(i) with 
respect to visibility for the 1997 8-hour ozone NAAQS and the 
PM2.5 NAAQS. As a result of the proposed disapproval, we are 
also proposing a FIP to address the requirements of section 
110(a)(2)(D)(i)(II) with respect to visibility to ensure that emissions 
from New Mexico sources do not interfere with the visibility programs 
of other states. We are proposing to find that New Mexico sources, 
other than one, are

[[Page 493]]

sufficiently controlled to eliminate interference with the visibility 
programs of other states, and for the one remaining source we are 
proposing to impose specific emissions limits that will eliminate such 
interstate interference. We are simultaneously evaluating whether the 
source at issue meets certain other related requirements under the 
Regional Haze (RH) program. As a result of this evaluation, we are 
likewise proposing to find that the proposed controls for the source at 
issue will address the NOX BART requirements of the RH 
program. In this action, we are not addressing whether the state has 
met other requirements of the RH program and will address those 
requirements in later actions.
    Section 110(a)(2)(D)(i)(II) of the Act requires that states have a 
SIP, or submit a SIP revision, containing provisions ``prohibiting any 
source or other type of emission activity within the state from 
emitting any air pollutant in amounts which will * * * interfere with 
measures required to be included in the applicable implementation plan 
for any other State under part C [of the CAA] to protect visibility.''
    Because of the impacts on visibility from the interstate transport 
of pollutants, we interpret the ``good neighbor'' provisions of section 
110 of the Act described above as requiring states to include in their 
SIPs measures to prohibit emissions that would interfere with the 
reasonable progress goals set to protect Class I areas in other states. 
New Mexico submitted a SIP to address these requirements in September 
2007. In this action, we are proposing to disapprove the New Mexico SIP 
submission as not meeting the requirements of section 
110(a)(2)(D)(i)(II) with respect to visibility. The SIP submission made 
by the state anticipated the timely submission of a substantive RH SIP 
submission as the means of meeting the requirements of section 
110(a)(2)(D)(i)(II). New Mexico has yet to submit such a RH SIP. In 
addition, the state has not revised its submission to address the 
requirements of section 110(a)(2)(D)(i)(II) with respect to visibility 
by any alternative means.
    By December 17, 2007, each State with one or more Class I Federal 
areas was also required to submit a RH SIP that included goals that 
provide for reasonable progress towards achieving natural visibility 
conditions. 40 CFR 51.308(d)(1). We previously found that New Mexico 
had failed to submit a complete RH SIP by December 17, 2007. 74 FR 2392 
(January 15, 2009). This finding started a two year clock for the 
promulgation of a RH FIP by EPA or the approval of a complete RH SIP 
from New Mexico. CAA Sec.  110(c)(1).
    To address the above concerns, we are also proposing to promulgate 
a FIP that ensures that emissions from New Mexico sources do not 
interfere with other states' measures to protect visibility in 
accordance with section 110(a)(2)(D)(i)(II) for the 1997 8-hour ozone 
and 1997 PM2.5 NAAQS, and also to address the requirements 
under the RH program for BART by imposing limits for NOX for 
the San Juan Generating Station (SJGS).\1\ This FIP will limit the 
emissions of SO2 and NOX from the SJGS. Together, 
the reduction in NOX from our proposed NOX BART 
determination, and the proposed SO2 emission limits to 
establish federal enforceability of current SO2 levels will 
serve to ensure there are enforceable mechanisms in place to prohibit 
New Mexico NOX and SO2 emissions from interfering 
with efforts to protect visibility in other states pursuant to the 
requirements of section 110(a)(2)(D)(i)(II) of the CAA. NOX 
and SO2 are significant contributors to visibility 
impairment in and around New Mexico. As the Four Corners Task Force 
notes,\2\ ``[r]eduction of NOX is particularly important to 
improve visibility at Mesa Verde National Park, which is 43 km away 
from SJGS. * * * [V]isibility has degraded at Mesa Verde over the past 
decade, and the portion of degradation due to nitrate has increased 
(while there has been no trend in degradation due to sulfate).'' For 
NOX emissions, we are proposing to require the SJGS to meet 
an emission limit of 0.05 pounds per million British Thermal Units (lb/
MMBtu) at Units 1, 2, 3, and 4, representing an approximately 83% 
reduction from the SJGS's baseline NOX emissions. This 
NOX limit is achievable by installing and operating 
Selective Catalytic Reduction (SCR). For SO2, we are 
proposing to require the SJGS to meet an emission limit of 0.15 lb/
MMBtu. Both of these emission limits would be measured on the basis of 
a 30-day rolling average. We are also proposing hourly average emission 
limits for sulfuric acid (H2SO4) and ammonia 
(NH3) for the SJGS, to minimize the contribution of these 
compounds to visibility impairment of Class I areas.
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    \1\ Unless otherwise specified, when we say the ``San Juan 
Generating Station,'' or ``SJGS,'' we mean units 1, 2, 3, and 4, 
inclusive.
    \2\ Power Plants Section, Four Corners Air Quality Task Force, 
Report of Mitigation Options, November 1, 2007, available at: http://www.nmenv.state.nm.us/aqb/4C/Docs/4CAQTF_Report_FINAL_PowerPlants.pdf.
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    Furthermore, we propose that compliance with the emission limits be 
within three (3) years of the effective date of our final rule. 
Additionally, we are proposing monitoring, recordkeeping, and reporting 
requirements to ensure compliance with emission limitations. Please see 
Section IV (Proposed Action) and the proposed regulation language at 
the end of this Federal Register action for more information.

II. Background

A. SIP and FIP Background

    The CAA requires each state to develop a plan that provides for the 
implementation, maintenance, and enforcement of the NAAQS. CAA section 
110(a). We establish NAAQS under section 109 of the CAA. Currently, the 
NAAQS address six (6) criteria pollutants: Carbon monoxide, nitrogen 
dioxide, ozone, lead, particulate matter, and sulfur dioxide. The plan 
developed by a state is referred to as the SIP. The content of the SIP 
is specified in section 110 of the CAA, other provisions of the CAA, 
and applicable regulations. 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 
the interstate transport of pollutants. CAA section 110(a)(2)(D)(i). 
States are required to update or revise SIPs under certain 
circumstances. See CAA section 110(a)(1). One such circumstance is our 
promulgation of a new or revised NAAQS. Id. Each state must submit 
these revisions to us for approval and incorporation into the 
federally-enforceable SIP.
    If a State fails to make a required SIP submittal or if we find 
that the State's submittal is incomplete or unapprovable, then we must 
promulgate a FIP to fill this regulatory gap. CAA section 110(c)(1). As 
discussed elsewhere in this notice, we have made findings related to 
New Mexico SIP revisions needed to address interstate transport and the 
requirement that emissions from New Mexico sources do not interfere 
with measures required in the SIP of any other state to protect 
visibility, pursuant to section 110(a)(2)(D)(i)(II) of the CAA. We are 
proposing a FIP to address the deficiencies in the New Mexico 
Interstate Transport SIP.

[[Page 494]]

B. Statutory and Regulatory Framework Addressing Interstate Transport 
and Visibility

1. The 1997 NAAQS for Ozone and PM2.5 and CAA 
110(a)(2)(D)(i)
    On July 18, 1997, we promulgated new NAAQS for 8-hour ozone and for 
PM2.5. 62 FR 38652. 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 
we may prescribe. Section 110(a)(2) of the CAA lists the elements that 
such new SIPs must address, as applicable, including section 
110(a)(2)(D)(i), which pertains to the interstate transport of certain 
emissions.
    On April 25, 2005, we published a ``Finding of Failure to Submit 
SIPs for Interstate Transport for the 8-hour Ozone and PM2.5 
NAAQS.'' 70 FR 21147. This included a finding that New Mexico and other 
states had failed to submit SIPs for interstate transport of air 
pollution affecting visibility, and started a 2-year clock for the 
promulgation of a FIP by us, unless a State made a submission to meet 
the requirements of section 110(a)(2)(D)(i) and we approved the 
submission. Id.
    On August 15, 2006, we issued our ``Guidance for State 
Implementation Plan (SIP) Submission 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). We 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) of the CAA 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.
    The 2006 Guidance stated that states may make a simple SIP 
submission confirming that it was not possible at that time to assess 
whether there is any interference with measures in the applicable SIP 
for another state designed to ``protect visibility'' for the 8-hour 
ozone and PM2.5 NAAQS until RH SIPs are submitted and 
approved. RH SIPs were required to be submitted by December 17, 2007. 
See 74 FR 2392 (January 15, 2009); see also discussion infra section 
II.B.2.
    On September 17, 2007 we received a SIP from New Mexico to address 
the interstate transport provisions of CAA 110(a)(2)(D)(i) for the 1997 
8-hour ozone and PM2.5 NAAQS. In this submission, the state 
indicated that it intended to meet the requirements of section 
110(a)(2)(D)(i)(II) with respect to visibility by submission of a 
timely RH SIP. To date, the state has not made a RH SIP submission. In 
addition, the state has not made a submission demonstrating 
noninterference with the visibility programs of other states in 
accordance with section 110(a)(2)(D)(i)(II) by any other means.
    In prior actions, we approved the New Mexico SIP submittal for (1) 
the ``significant contribution to nonattainment'' prong of section 
110(a)(2)(D)(i) (75 FR 33174, June 11, 2010) and (2) the ``interfere 
with maintenance'' and ``interfere with measures to prevent significant 
deterioration'' prongs of section 110(a)(2)(D)(i) (75 FR 72688, 
November 26, 2010). In this action, we are proposing to disapprove the 
New Mexico Interstate Transport SIP with respect to the requirement 
that emissions from New Mexico sources do not interfere with measures 
required in the SIP of any other state to protect visibility. See CAA 
section 110(a)(2)(D)(i)(II). We are proposing to promulgate a FIP in 
order to cure this defect in the New Mexico Interstate Transport SIP.
2. Visibility Protection
    In section 169A of the 1977 Amendments to the CAA, Congress created 
a program for protecting visibility in the nation's national parks and 
wilderness areas. This section of the CAA establishes as a national 
goal the ``prevention of any future, and the remedying of any existing, 
impairment of visibility in mandatory Class I Federal areas \3\ which 
impairment results from manmade air pollution.'' CAA Sec.  169A(a)(1). 
The terms ``impairment of visibility'' and ``visibility impairment'' 
are defined in the Act to include a reduction in visual range and 
atmospheric discoloration. Id. section 169A(g)(6). In 1980, we 
promulgated regulations to address visibility impairment in Class I 
areas that is ``reasonably attributable'' to a single source or small 
group of sources, i.e., ``reasonably attributable visibility 
impairment'' (RAVI). 45 FR 80084 (December 2, 1980). These regulations 
represented the first phase in addressing visibility impairment. We 
deferred action on RH that emanates from a variety of sources until 
monitoring, modeling and scientific knowledge about the relationships 
between pollutants and visibility impairment were improved. Id.
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    \3\ Areas designated as mandatory Class I Federal areas consist 
of national parks exceeding 6,000 acres, wilderness areas and 
national memorial parks exceeding 5,000 acres, and all international 
parks that were in existence on August 7, 1977. CAA section 162(a). 
In accordance with section 169A of the CAA, EPA, in consultation 
with the Department of Interior, promulgated a list of 156 areas 
where visibility is identified as an important value. See 44 FR 
69122 (November 30, 1979). The extent of a mandatory Class I area 
includes subsequent changes in boundaries, such as park expansions. 
CAA section 162(a). Although states and tribes may designate as 
Class I additional areas which they consider to have visibility as 
an important value, the requirements of the visibility program set 
forth in section 169A of the CAA apply only to ``mandatory Class I 
Federal areas.'' Each mandatory Class I Federal area is the 
responsibility of a ``Federal Land Manager'' (FLM). CAA section 
302(i). When we use the term ``Class I area'' in this action, we 
mean a ``mandatory Class I Federal area.''
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    Congress added section 169B to the CAA in 1990 to address RH 
issues, and we promulgated regulations addressing RH in 1999. 64 FR 
35714 (July 1, 1999), codified at 40 CFR part 51, subpart P (the 
regional haze rule or RHR). The RHR revised the existing visibility 
regulations to integrate provisions addressing RH impairment and 
established a comprehensive visibility protection program for Class I 
areas. The requirements for RH, found at 40 CFR 51.308 and 51.309, are 
included in our visibility protection regulations at 40 CFR 51.300-309. 
States were required to submit the first SIP addressing RH visibility 
impairment no later than December 17, 2007. 40 CFR 51.308(b).
    On January 15, 2009, we published a ``Finding of Failure to Submit 
State Implementation Plans Required by the 1999 regional haze rule.'' 
74 FR 2392. We found that New Mexico and other states had failed to 
submit for our review and approval complete SIPs for improving 
visibility in the nation's national parks and wilderness areas by the 
required date of December 17, 2007. We found that New Mexico failed to 
submit the plan elements required by 40 CFR 51.309(g), the reasonable 
progress requirements for areas other than the 16 Class I areas covered 
by the Grand Canyon Visibility Transport Commission Report. New Mexico 
also failed to submit the plan element required by 40 CFR 51.309(d)(4), 
which

[[Page 495]]

requires BART for stationary source emissions of NOx and PM 
under either 40 CFR 51.308(e)(1) or 51.308(e)(2).\4\ This finding 
started a 2-year clock for the promulgation of a FIP by EPA, unless the 
State made a RH SIP submission and we approved it.
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    \4\ NM has an option to submit a RH SIP under either section 
51.308 or section 51.309. Although they have indicated their 
preference is for the latter, the NOx BART FIP we are 
proposing would apply to either.
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3. Best Available Retrofit Technology
    Section 169A of the CAA directs states to evaluate the use of 
retrofit controls at certain major stationary sources with the 
potential to emit greater than 250 tons or more of any pollutant, in 
order to address visibility impacts from these sources. Specifically, 
it requires states to revise their SIPs to contain such measures as may 
be necessary to make reasonable progress towards the natural visibility 
goal, including a requirement that certain categories of existing major 
stationary sources built between 1962 and 1977 procure, install, and 
operate the ``Best Available Retrofit Technology,'' as determined by 
the State or us in the case of a plan promulgated under section 110(c) 
of the CAA. CAA section 169A(b)(2)(A). States are directed to conduct 
BART determinations for such sources that may be anticipated to cause 
or contribute to any visibility impairment in a Class I area. The RHR 
required all states to submit implementation plans that, among other 
measures, contain either emission limits representing BART for certain 
sources constructed between 1962 and 1977, or alternative measures that 
provide for greater reasonable progress than BART. 40 CFR 51.308(e). On 
July 6, 2005, we published the Guidelines for BART Determinations Under 
the Regional Haze Rule (``BART Guidelines'') to assist states in 
determining which of their sources should be subject to the BART 
requirements and in determining appropriate emission limits for each 
applicable source. 70 FR 39104.
    The process of establishing BART emission limitations can be 
logically broken down into three steps: first, states identify those 
sources which meet the definition of ``BART-eligible source'' set forth 
in 40 CFR 51.301 \5\; second, states determine whether each source 
``emits any air pollutant which may reasonably be anticipated to cause 
or contribute to any impairment of visibility in any such area'' (a 
source which fits this description is ``subject to BART''); and third, 
for each source subject to BART, states then identify the appropriate 
type and the level of control for reducing emissions.
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    \5\ BART-eligible sources are those sources, which have the 
potential to emit 250 tons or more of a visibility-impairing air 
pollutant, that were put in place between August 7, 1962 and August 
7, 1977, and whose operations fall within one or more of 26 
specifically listed source categories.
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    States must consider the following factors in making BART 
determinations: (1) The costs of compliance; (2) the energy and nonair 
quality environmental impacts of compliance; (3) any existing pollution 
control technology in use at the source; (4) the remaining useful life 
of the source; and (5) the degree of improvement in visibility which 
may reasonably be anticipated to result from the use of such 
technology. 40 CFR 51.308(e)(1)(ii)(A). Section 51.308(e)(1)(ii)(B) 
requires that BART determinations for fossil fuel-fired electric 
generating plants with a total generating capacity in excess of 750 
megawatts, must be made according to the BART Guidelines.\6\ A state is 
encouraged, but not required, to follow the BART Guidelines in making 
BART determinations for other types of sources.
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    \6\ Appendix Y to 40 CFR Part 51--Guidelines for BART 
Determinations Under the Regional Haze Rule.
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    States must address all visibility-impairing pollutants emitted by 
a source in the BART determination process. The most significant 
visibility impairing pollutants are SO2, NOX, and 
PM. We have stated that states should use their best judgment in 
determining whether volatile organic compounds (VOCs) or ammonia 
(NH3) and ammonia compounds impair visibility in Class I 
areas.
    The Regional Planning Organizations (RPOs) provided air quality 
modeling to the states to help them in determining whether potential 
BART sources can be reasonably expected to cause or contribute to 
visibility impairment in a Class I area. Under the BART Guidelines, 
states may select an exemption threshold value for their BART modeling, 
below which a BART-eligible source would not be expected to cause or 
contribute to visibility impairment in any Class I area. 70 FR 39104. 
The state must document this exemption threshold value in the SIP and 
must state the basis for its selection of that value. Id. Any source 
with emissions that model above the threshold value would be subject to 
a BART determination review. Id. The BART Guidelines acknowledge 
varying circumstances affecting different Class I areas. States should 
consider the number of emission sources affecting the Class I areas at 
issue and the magnitude of the individual sources' impacts. Id. Any 
exemption threshold set by the state should not be higher than 0.5 
deciview. Id.
    The RHR establishes the deciview (dv) as the principal metric for 
measuring visibility. Id. This visibility metric expresses uniform 
changes in haziness in terms of common increments across the entire 
range of visibility conditions, from pristine to extremely hazy 
conditions. Visibility is sometimes expressed in terms of the visual 
range which is the greatest distance, in kilometers or miles, at which 
a dark object can just be distinguished against the sky. The deciview 
is a more useful measure for tracking progress in improving visibility, 
because each deciview change is an equal incremental change in 
visibility perceived by the human eye. Most people can detect a change 
in visibility at one deciview.
    A RH SIP must include source-specific BART emission limits and 
compliance schedules for each source subject to BART. Once a state has 
made its BART determination, the BART controls must be installed and in 
operation as expeditiously as practicable, but no later than five (5) 
years after the date of our approval of the RH SIP. CAA section 
169(g)(4); 40 CFR 51.308(e)(1)(iv). In addition to what is required by 
the RHR, general SIP requirements mandate that the SIP must also 
include all regulatory requirements related to monitoring, 
recordkeeping, and reporting for the BART controls on the source. See 
CAA section 110(a)(2).
4. The Western Regional Air Partnership and Evaluation of Regional Haze 
Impacts
    The Western Regional Air Partnership (WRAP) is a voluntary 
partnership of state, tribal, federal, and local air agencies dealing 
with regional air quality issues in the West. Member states include 
Alaska, Arizona, California, Colorado, Idaho, Montana, New Mexico, 
North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. The 
WRAP established various committees to assist in managing and 
developing RH work products. New Mexico is a WRAP member. The WRAP 
evaluates air quality impacts, including RH impacts, associated with 
regionally significant emission sources. In so doing, the WRAP has 
conducted air quality modeling. The states in the West have

[[Page 496]]

used this modeling to establish their reasonable progress goals for 
RH.\7\
---------------------------------------------------------------------------

    \7\ More information on WRAP and their work can be found on the 
Internet at http://www.wrapair2.org and in the TSD for this action.
---------------------------------------------------------------------------

    The RH program, as reflected in the regulations, recognizes the 
importance of addressing the long-range transport of pollutants for 
visibility and encourage states to work together to develop plans to 
address haze. The regulations explicitly require each State to address 
its ``share'' of the emission reductions needed to meet the reasonable 
progress goals for surrounding Class I areas. States working together 
through a regional planning process are required to address an agreed 
upon share of their contribution to visibility impairment in the Class 
I areas of their neighbors. 40 CFR 51.308(d)(3)(ii). The States in the 
West worked together through the WRAP to determine their contribution 
to visibility impairment at the relevant federal Class I areas in the 
region and the emissions reductions from each State needed to attain 
the reasonable progress goals for each area. Regional planning 
organizations (RPOs) such as the WRAP provided much of the technical 
work necessary to develop RH SIPs, including the modeling used to 
establish reasonable progress goals. The WRAP evaluated air quality 
impacts, including RH impacts, associated with regionally significant 
emission sources. In so doing, the WRAP conducted air quality modeling. 
The modeling done by the RPOs relied on assumptions regarding emissions 
over the relevant planning period. Embedded in these assumptions were 
anticipated emissions reductions from each of the states in the RPO, 
including reductions from BART and other measures to be adopted as part 
of the states long-term strategy for addressing RH. The states in the 
West, in turn, have used this modeling to establish their reasonable 
progress goals for RH. The reasonable progress goals in the draft and 
final RH SIPs that have now been prepared by states in the West 
accordingly are based, in part, on the emissions reductions from nearby 
states that were agreed on through the WRAP process.

III. Our Evaluation

A. New Mexico's Interstate Transport SIP

    We received a SIP from New Mexico to address the interstate 
transport provisions of CAA 110(a)(2)(D)(i) for the 1997 8-hour ozone 
and PM2.5 NAAQS on September 17, 2007. Concerning the 
provision preventing sources in the state from emitting pollutants in 
amounts which will interfere with efforts to protect visibility in 
other states, New Mexico stated that:
     New Mexico sources of emissions do not interfere with 
implementation of reasonably attributable visibility impairment;
     Its December 2003 RH SIP demonstrated reasonable progress 
in reducing impacts on Class I areas on the Colorado Plateau;\8\ and
---------------------------------------------------------------------------

    \8\ In December, 2003, New Mexico submitted its RH SIP pursuant 
to the requirements of sections 169A and 169B of the CAA and the 
regional haze rule. However, in American Corn Growers Ass'n v. EPA, 
291 F.3d 1 (DC Cir. 2002), the U.S. Court of Appeals for the 
District of Columbia Circuit issued a ruling vacating and remanding 
the BART provisions of the regional haze rule. In 2006, EPA issued 
BART guidelines to address the court's ruling in that case. See 70 
FR 39104 (July 6, 2005). On January 13, 2009, New Mexico resubmitted 
portions of its RH SIP, but not the requirements addressing 
reasonable progress pursuant to 40 CFR 51.309(g).
---------------------------------------------------------------------------

     The 2007 SIP update for RH will analyze any impacts from 
New Mexico that extend beyond the Colorado Plateau and determine 
appropriate long-term strategies for control measures. As mentioned 
previously, New Mexico has yet to provide this SIP revision.
    New Mexico's submission addressed the requirement that it not 
interfere with the visibility programs of other states by stating that 
it would submit an approvable RH SIP by December 2007. The state did 
not otherwise establish that emissions from its sources would not 
interfere with the visibility programs of other states. After 
intervening events precluded the development of an approvable RH SIP, 
the state did not make any subsequent SIP submission to address the 
requirements of section 110(a)(2)(D)(i)(II) with respect to impacts on 
the visibility programs of other states. Consequently, because the 
State did not submit a RH SIP or an alternative means of demonstrating 
that emissions from its sources would not interfere with the visibility 
programs of other States, we are proposing disapproval of the SIP 
received September 17, 2007, with respect to 110(a)(2)(D)(i)(II) and 
visibility protection. Further, as described in subsequent sections, we 
are proposing that additional controls are necessary to prevent 
emissions from New Mexico from interfering with measures to protect 
visibility in other States.

B. Federal Implementation Plan To Address Interstate Transport and 
Visibility and the BART Requirements for NOX

    As an initial matter, we note that section 110(a)(2)(D)(i)(II) does 
not explicitly specify how we should ascertain whether a state's SIP 
contains adequate provisions to prevent emissions from sources in that 
state from interfering with measures required in another state to 
protect visibility. Thus, the statute is ambiguous on its face, and we 
must interpret that provision.
    Our 2006 Guidance recommended that a state could meet the 
visibility prong of the transport requirements of section 
110(a)(2)(D)(i)(II) of the CAA by submission of the RH SIP, due in 
December 2007. Our reasoning was that the development of the RH SIPs 
was intended to occur in a collaborative environment among the states. 
In fact, in developing their respective reasonable progress goals, WRAP 
states consulted with each other through the WRAP's work groups.\9\ As 
a result of this process, the common understanding was that each State 
would take action to achieve the emissions reductions relied upon by 
other states in their reasonable progress demonstrations under the RHR. 
This effort included all states in the WRAP region contributing 
information to a Technical Support System (TSS) which provides an 
analysis of the causes of haze, and the levels of contribution from all 
sources within each state to the visibility degradation of each Class I 
area. The WRAP states consulted in the development of reasonable 
progress goals, using the products of this technical consultation 
process to co-develop their reasonable progress goals for the Western 
Class I areas.
---------------------------------------------------------------------------

    \9\ Consultation provided through the WRAP have been documented 
in calls and meetings on the WRAP Web site, available at http://www.wrapair.org/cal/calendar.php.
---------------------------------------------------------------------------

    We believe that the analysis conducted by the WRAP provides an 
appropriate means for designing a FIP that will ensure that emissions 
from sources in New Mexico are not interfering with the visibility 
programs of other states, as contemplated in section 
110(a)(2)(D)(i)(II). In developing their visibility projections using 
photochemical grid modeling, the WRAP states assumed a certain level of 
emissions from sources within New Mexico. Although we have not yet 
received all RH SIPs, we understand that the WRAP states used the 
visibility projection modeling to establish their own respective 
reasonable progress goals. Thus, we believe that an implementation plan 
that provides for emissions reductions consistent with the assumptions 
used in the WRAP modeling will ensure that emissions from New Mexico 
sources do not

[[Page 497]]

interfere with the measures designed to protect visibility in other 
states.
    Accordingly, we have reviewed the WRAP photochemical modeling 
emission projections used in the demonstration of reasonable progress 
towards natural visibility conditions and compared them to current 
emission levels from sources in New Mexico. We have concluded that all 
of the sources in New Mexico are achieving the emission levels assumed 
by the WRAP in its modeling except for the SJGS. The WRAP modeling 
assumed the SJGS's NOX emissions would be 0.27 lbs/MMBtu for 
units 1 and 3, and 0.28 lbs/MMBtu for units 2 and 4, in 2018. The WRAP 
modeling also assumed SO2 emissions would be 0.15 lbs/MMBtu 
in 2018 for the four SJGS units.
    The SJGS consists of four (4) coal-fired generating units and 
associated support facilities. Each coal-fired unit burns pulverized 
coal and No. 2 diesel oil (for startup) in a boiler, and produces high-
pressure steam which powers a steam turbine coupled with an electric 
generator. Electric power produced by the units is supplied to the 
electric power grid for sale. Coal for the units is supplied by the 
adjacent San Juan Mine and is delivered to the facility by conveyor. 
Units 1 and 2 have a unit capacity of 350 and 360 MW, respectively. 
Units 3 and 4 each have a unit capacity of 544 MW.
    In 2005, the operator of the SJGS, Public Service Company of New 
Mexico (PNM), entered into a consent decree with the Grand Canyon 
Trust, Sierra Club, and the New Mexico Environment Department (NMED) to 
reduce emissions of NOX, SO2, particulate matter 
and mercury.\10\ The consent decree imposed emissions restrictions, 
including the following:
---------------------------------------------------------------------------

    \10\ Consent Decree in The Grand Canyon Trust and Sierra Club, 
Plaintiffs, The State of New Mexico, Plaintiff-Intervenor, v. Public 
Service Company of New Mexico, Defendant, (CV 02-552 BB/ACT (ACE)), 
lodged in the United States District Court, District of New Mexico, 
on March 10, 2005, at 15-16.
---------------------------------------------------------------------------

     NOX: 0.30 lb/mmBtu on a 30-day rolling average.
     SO2: 90% annual average control, not to exceed 
0.250 lb/mmBtu for a seven-day block average.
    In a permit modification to the construction permit for SJGS, NMED 
issued a revised construction permit (NSR Air Quality Permit No. 0063-
M6) on April 22, 2008 to incorporate some of the conditions from the 
consent decree. The construction permit was issued by the Air Quality 
Bureau of the NMED to SJGS pursuant to the New Mexico Air Quality 
Control Act and regulations and is considered a federally enforceable 
permit. We were not a party to the consent decree, but the inclusion of 
limits from the consent decree that have been included in the 
construction permit for the facility were issued pursuant to the 
federally approved construction permitting program of the New Mexico 
SIP. Specifically, the construction permit includes the NOX 
and SO2 limits from the consent decree that are identified 
above.\11\ Therefore, these NOX and SO2 emissions 
restrictions are federally enforceable. This permit has since been 
superseded by a further construction permit modification that also 
includes the consent decree limits on NOX and SO2 
emissions and is federally enforceable.\12\
---------------------------------------------------------------------------

    \11\ NOX limit of 0.30 lb/mmBtu on a 30-day rolling 
average for each of the four units; SO2 limit of 90% 
annual average control for each unit, with a short-term limit not to 
exceed 0.250 lb/mmBtu for a seven-day block average.
    \12\ New Mexico Environment Department Air Quality Bureau NSR 
Air Quality Permit No. 0063-M6R1 was issued on September 12, 2008 
and superseded Permit No. 0063-M6.
---------------------------------------------------------------------------

    Although the SJGS is subject to a federally enforceable permit, the 
permit's 30-day rolling average NOX emission limit of 0.30 
lb/mmBtu for all units is less restrictive than the emission rates 
modeled by the WRAP of 0.27 lbs/MMBtu for units 1 and 3, and 0.28 lbs/
MMBtu for units 2 and 4 in assessing the daily visibility impacts. We 
also note the WRAP photochemical modeling utilized an SO2 
emission rate of 0.15 lbs/MMBtu on a continuous basis for all four 
units. In previous communications to New Mexico and the WRAP, PNM 
indicated that the 90% annual average control specified in the permit 
would be expected to yield roughly an annual average emission rate of 
0.195 lb/mmBtu of SO2,\13\ which is much higher than the 
0.15 lb/mmBtu emission rate utilized in the WRAP's photochemical 
modeling for assessing daily level impacts. Also, the 90% 
SO2 control restriction specified in the permit is an annual 
average, which allows for short term fluctuations. It also is not 
directly translatable to an emission limit (e.g., lbs/MMBtu), and 
requires knowledge of the sulfur content of the coal being burned. 
Therefore, this limit can further fluctuate depending upon the annual 
average sulfur content of the coal. This presents an unnecessary 
enforcement complication. The permit also specifies a 0.250 lb/mmBtu on 
a 7-day block average for each unit, which is much less restrictive 
than the 0.15 lb/mmBtu emission rate that was used within the WRAP's 
photochemical modeling.
---------------------------------------------------------------------------

    \13\ Comments Received to-Date on the Draft 2018 Base Case 
Projections, Version: December 21, 2005, available at http://www.wrapair.org/forums/ssjf/documents/eictts/Projections/Summary%20of%20Comments_122105_final.pdf, pdf pagination 20.
---------------------------------------------------------------------------

    Therefore, the permit does not provide the necessary emission 
limits and enforceable mechanisms to ensure the NOX and 
SO2 emissions used in the WRAP photochemical modeling for 
the SJGS units will be met. In the absence of an approvable RH SIP, we 
do not have an enforceable mechanism for ensuring that sources in New 
Mexico do not impact visibility in other states. Other WRAP states are 
relying on levels modeled for the SJGS units, developed in 
consultation, in their demonstration of reasonable progress towards 
natural visibility conditions. Therefore, any discrepancies between 
what was included in the WRAP photochemical modeling and what is 
presently enforceable, is a concern. We have evaluated these 
discrepancies and determined they are significant due to the changes in 
visibility projections in the modeling. We have concluded that it is 
appropriate to establish federally enforceable limits for pollutants 
that impact visibility projections within the WRAP photochemical 
modeling.
    As discussed in II.A, we are proposing to disapprove New Mexico 
Interstate Transport SIP provisions 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 protect visibility. In addition, since New 
Mexico has not submitted a complete RH SIP that should have, among 
other things, included a review of BART for NOX at the SJGS, 
and for both of these requirements we have made a finding of failure to 
submit,\14\ giving us the authority and responsibility to issue a FIP 
to address the deficiencies in the State's plan, we are also proposing 
to find that New Mexico sources, except the SJGS, are sufficiently 
controlled to eliminate interference with the visibility programs of 
other states. For the SJGS we are proposing to impose specific 
emissions limits that will eliminate such interstate interference based 
on current emissions that satisfies the assumptions in the WRAP 
modeling.
---------------------------------------------------------------------------

    \14\ See Finding of Failure to Submit SIPs for Interstate 
Transport for the 8-hour Ozone and PM2.5 NAAQS. 70 FR 
21147 (April 25, 2005); see also Finding of Failure To Submit State 
Implementation Plans Required by the 1999 Regional Haze Rule. 74 FR 
2392 (January 15, 2009).
---------------------------------------------------------------------------

    The following sections outline our proposal for addressing the BART 
requirements for NOX at SJGS and for ensuring that the SJGS 
has the controls necessary to prevent emissions from

[[Page 498]]

New Mexico from interfering with the reasonable progress goals in other 
states.
1. Additional SO2 Emission Limits for the SJGS
    As we discuss above, there are no federally enforceable limits that 
restrict the SJGS's SO2 emissions at 0.15 lbs/MMBtu, the 
rate assumed by the WRAP in its modeling. Therefore, as part of this 
action, we are proposing to impose an SO2 emission rate of 
0.15 lbs/MMBtu on a 30 day rolling average for units 1, 2, 3, and 4 of 
the SJGS. By imposing this limit through this action, we will insure 
that SO2 emissions from this source are not interfering with 
the visibility programs of other states. We note an examination of the 
SJGS's actual emission rates based on emissions reported by our Clean 
Air Markets Division \15\ indicates units 1, 2, 3, and 4 of the SJGS 
are already meeting these SO2 emission limits.
---------------------------------------------------------------------------

    \15\ http://camddataandmaps.epa.gov/gdm/index.cfm.
---------------------------------------------------------------------------

    We are not making a finding that this SO2 emission limit 
satisfies BART for SO2. NMED has indicated they will submit 
a RH SIP under 40 CFR 51.309, thus SO2 BART for the SJGS 
will be addressed through New Mexico's participation in an 
SO2 trading program, under 40 CFR 51.309(d)(4). Should NMED 
instead submit a RH SIP under 40 CFR 51.308, the SJGS would be subject 
to an SO2 BART analysis under 40 CFR 51.308(e).
2. Need for Additional NOX Controls
    As we discuss above, the WRAP assumed in its modeling that the SJGS 
would achieve NOX emission rates of 0.27 lbs/MMBtu for units 
1 and 3, and 0.28 lbs/MMBtu for units 2 and 4 in its evaluation of 
daily impacts in photochemical modeling. Based on our approach of 
relying on the assumptions in the WRAP modeling, additional control 
would, therefore, be necessary to ensure that emissions from New Mexico 
sources do not interfere with efforts to protect visibility in other 
states pursuant to the requirements of section 110(a)(2)(D)(i)(II) of 
the CAA.
    Unlike the case for SO2, the SJGS will have to install 
controls and therefore make capital investments to achieve these 
additional NOX reductions. As we note above, on January 15, 
2009, we published a ``Finding of Failure to Submit State 
Implementation Plans Required by the 1999 regional haze rule.'' 74 FR 
2392. This finding included the plan element required by 40 CFR 
51.309(d)(4), which requires BART for stationary source emissions of 
NOX and PM under either 40 CFR 51.308(e)(1) or 51.308(e)(2). 
Therefore, rather than making an initial determination to require the 
controls needed to prevent interference with the visibility programs of 
other states based on the assumptions in the WRAP photochemical 
modeling to meet section 110(a)(2)(D)(i)(II) requirements, followed 
soon thereafter by a separate NOX BART evaluation, we find 
it is appropriate to perform that BART evaluation at this time. 
Addressing both outstanding obligations at this time will be more 
efficient and will provide greater certainty to the source as to the 
appropriate NOX controls needed to meet these two separate 
but related requirements. Our evaluation of BART for NOX 
follows.
3. NOX BART Evaluation
    In June, 2007, PNM submitted its BART evaluation to NMED. That 
evaluation was revised multiple times to incorporate additional 
visibility modeling analyses, control technology considerations, and 
cost analyses. Although not officially submitted to us, NMED completed 
a NOX and PM BART determination for the SJGS (referred to 
herein as the ``NMED BART evaluation''), which we have found to be 
thorough and comprehensive.\16\ In making our NOX BART 
determination for the SJGS, we drew heavily upon the NOX 
BART portion of that document, and used it to help inform our 
NOX BART determination for the SJGS. We have incorporated it 
into our Technical Support Document (TSD) found in the electronic 
docket for this action. The electronic docket can be found at the Web 
site http://www.regulations.gov (docket number EPA-R06-OAR-2010-0846).
---------------------------------------------------------------------------

    \16\ New Mexico Environment Department, Air Quality Bureau, BART 
Determination, Public Service Company of New Mexico, San Juan 
Generating Station, Units 1-4, June 21, 2010, available at http://www.nmenv.state.nm.us/aqb/reghaz/documents/AppxA_NM_SJGS_NOxBARTDetermination_06212010.pdf.
---------------------------------------------------------------------------

    We have determined, as outlined below, that the SJGS is subject to 
BART and are proposing to require that units 1, 2, 3, and 4 meet an 
emission limit for NOX of 0.05 lbs/MMBtu. This limit is 
based on the installation of SCR on each of the units. The following 
steps outline how we came to this determination. For more detail, 
please see the TSD. Any BART determinations for other pollutants that 
may be warranted under the RHR will be addressed in future rulemakings.
a. The SJGS Is a BART-Eligible Source
    The first step of a BART evaluation is to determine whether a 
source meets the definition of a ``BART-eligible source'' in 40 CFR 
51.301. BART-eligible sources are those sources which have the 
potential to emit 250 tons or more of a visibility-impairing air 
pollutant, were put in place between August 7, 1962 and August 7, 1977, 
and whose operations fall within one or more of 26 specifically listed 
source categories. We find, based on emissions reported by our Clean 
Air Markets Division,\17\ that units 1, 2, 3, and 4 of the SJGS each 
have historically emitted much more than 250 tons of NOX. 
Also, according to the NMED SJGS Title V Statement of Basis, units 1, 
2, 3, and 4 of the SJGS meet the requirement of being ``in existence'' 
on August 7, 1977 but not ``in operation'' before August 7, 1962. 
Lastly, we find that units 1, 2, 3, and 4 of the SJGS fall under 
category 1 of the 26 listed BART categories, which is fossil-fuel fired 
steam electric plants of more than 250 million British thermal units 
(BTU) per hour heat input. Therefore, we propose to find that units 1, 
2, 3, and 4 of the SJGS are BART-eligible.
---------------------------------------------------------------------------

    \17\ http://camddataandmaps.epa.gov/gdm/index.cfm.
---------------------------------------------------------------------------

b. The SJGS Is Subject to BART
    Section III of the BART Guidelines outlines several approaches for 
identifying sources that are subject to BART. This entails making a 
determination of whether the units of the SJGS cause or contribute to 
visibility impairment in nearby Class I areas. Among the options we 
recommended was the use of dispersion modeling for assessing the 
impacts of a single source. As we note in the BART Guidelines, one of 
the first steps in this approach to determining whether a source causes 
or contributes to visibility impairment is to establish a threshold 
(measured in deciviews). A single source that is responsible for a 1.0 
deciview change or more should be considered to ``cause'' visibility 
impairment; a source that causes less than a 1.0 deciview change may 
still contribute to visibility impairment and thus be subject to BART. 
We note in the BART Guidelines that states (and by extension EPA when 
promulgating a FIP) have flexibility in determining an appropriate 
threshold for determining whether a source ``contributes to any 
visibility impairment'' for the purposes of BART. However, this 
threshold should not be higher than 0.5 deciviews.\18\ In the case of 
the SJGS, this establishment of a precise threshold for contribution is 
moot, since visibility modeling indicates that even using the upper 
bound contribution threshold of 0.5 deciviews, the SJGS contributes to

[[Page 499]]

visibility impairment at a number of Class I areas.
---------------------------------------------------------------------------

    \18\ 40 FR 39161 (July 6, 2005).
---------------------------------------------------------------------------

    The WRAP performed the initial BART screening modeling for the 
state of New Mexico. The procedures used are outlined in the WRAP 
Regional Modeling Center (RMC) BART Modeling Protocol.\19\ The WRAP 
screening modeling evaluated sources that were identified as BART-
eligible and determined the only sources that did not screen out were 
the SJGS units. The results of this analysis indicated that SJGS, on a 
facility-wide basis, causes visibility impairment at all 16 Class I 
areas within 300 km of the facility. However, this modeling was based 
on the installed control technology at the time and does not reflect 
emission reductions due to the installation of consent decree controls. 
Revised modeling performed by NMED and by us, including controls 
required by the consent decree and currently installed, further 
confirmed that SJGS still ``causes'' visibility impairment at more than 
half of the Class I areas in the vicinity of the facility and 
contributes (above 0.5 deciviews) to visibility impairment at the 
remaining areas on a facility-wide basis. On an individual unit basis, 
all units ``cause'' visibility impairment at Mesa Verde National Park, 
and cause or contribute to visibility impairment at a number of other 
Class I areas. Our modeling indicates that the visibility impairment is 
primarily dominated by nitrate particulates. Therefore, as the WRAP 
screening modeling has previously concluded and further New Mexico and 
our modeling confirms that even with post-consent decree control levels 
on SJGS units, the SJGS units 1, 2, 3, and 4 still have a significant 
impact at surrounding Class I areas. Consequently, we propose to find 
that units 1, 2, 3, and 4 of the SJGS are subject to BART. More details 
on this determination can be found in the TSD.
---------------------------------------------------------------------------

    \19\ ``CALMET/CALPUFF Protocol for BART Exemption Screening 
Analysis for Class I Areas in the Western United States'', Western 
Regional Air Partnership (WRAP); Gail Tonnesen, Zion Wang; Ralph 
Morris, Abby Hoats and Yiqin Jia, August 15, 2006, available at 
http://pah.cert.ucr.edu/aqm/308/bart/WRAP_RMC_BART_Protocol_Aug15_2006.pdf.
---------------------------------------------------------------------------

c. The SJGS NOX BART Determination
    Having established that units 1, 2, 3, and 4 of the SJGS are 
subject to BART, the next requirement is to perform the BART Analysis. 
40 CFR 51.308(e)(1)(ii); see also BART Guidelines, Section IV. The BART 
analysis identifies the best system of continuous emission reduction 
and, as laid out in the BART Guidelines, consists of the following five 
basic steps:
     Step 1: Identify All Available Retrofit Control 
Technologies;
     Step 2: Eliminate Technically Infeasible Options;
     Step 3: Evaluate Control Effectiveness of Remaining 
Control Technologies;
     Step 4: Evaluate Impacts and Document the Results; and
     Step 5: Evaluate Visibility Impacts.
    As we stated above, for our BART analysis we have heavily drawn 
upon the NMED BART Evaluation. Except for the following points, we 
agree with NMED's conclusions regarding Steps 1-5:
     PNM's cost estimate. NMED questioned PNM's cost estimate 
for the installation of SCR but accepted it as being cost effective. We 
too questioned PNM's cost estimate for SCR, and hired a consultant to 
undertake an accurate assessment of the cost of SCR and the emission 
limits that SCR is capable of attaining. (For more information, please 
see the TSD).
     BART for NOX. NMED evaluated the visibility 
benefits of SCR at the SJGS based on an emission limit of 0.07 lbs/
MMBtu, but noted the potential for greater control at rates as low as 
0.03 lbs/MMBtu. As discussed further below, we have concluded that a 
NOX emission limit of 0.05 lbs/MMBtu is BART for the SJGS, 
and performed our visibility modeling on that basis. (Additional 
information is provided in the TSD).
     SO2 to SO3 Conversion. NMED 
concluded BART for the SJGS was SCR plus sorbent injection to remove 
sulfur trioxide (SO3) in the flue gas by reaction with an 
alkaline material. As discussed further below, we have concluded that 
sorbent injection is not necessary, as the SJGS burns a low sulfur 
coal, and catalysts are available with a low SO2 to 
SO3 conversion rate. (Please see the TSD for further 
information).
    The following is a summary of our BART analysis. In general, our 
analysis is the same as NMED's analysis of Steps 1-5, as modified to 
incorporate the areas discussed above in which we differ with NMED.
i. Identification of All Available Retrofit Emission Control 
Technologies
    To address step 1, NMED reviewed a number of potential 
retrofittable NOX control technologies, including: Selective 
Non Catalytic Reduction (SNCR), SCR, SNCR/SCR Hybrid, Natural Gas 
Reburn, Nalco Mobotec ROFA and Rotamix, NOxStar, ECOTUBE, PowerSpan 
ECO, Phenix Clean Combustion, and e-SCRUB. We drew upon PNM's June, 
2007 BART submission to NMED and its subsequent revisions in our 
evaluation, and agree that the potential technologies for 
NOX controls that have been identified.
ii. Elimination of Technically Infeasible Options
    For step 2, again drawing upon the NMED analysis, we have 
determined the following potentially retrofittable NOX 
control technologies are not technically feasible, or have not been 
thoroughly demonstrated on similar size and type units: Natural Gas 
Reburn, NOxStar, ECOTUBE, PowerSpan ECO, Phenix Clean Combustion, and 
e-SCRUB. In determining BART, we have considered the remaining 
technologies, SCR, SNCR, SNCR/SCR Hybrid, and the Nalco Mobotec ROFA 
and Rotamix to be technically feasible.
iii. Evaluation of Control Effectiveness of Remaining Control 
Technologies
    Step 3 involves evaluating the control effectiveness of all the 
technically feasible control alternatives identified in Step 2. Two key 
issues in this process include: (1) Ensuring the degree of control is 
expressed using a metric that ensures a level comparison of emissions 
performance levels among options; and (2) giving appropriate treatment 
and consideration of control techniques that can operate over a wide 
range of emission performance levels. With the exception of SCR, Table 
1 represents the control efficiencies and control emission rates PNM 
reported as part of its BART analyses \20\ to NMED for the 
NOX controls that were found to be technically feasible. In 
our own SCR cost analysis, which we present later in this section, we 
have revised the control efficiency for SCR from 0.07 lbs/MMBtu to 0.05 
lbs/MMBtu.
---------------------------------------------------------------------------

    \20\ Public Service Company of New Mexico, San Juan Generating 
Station, Best Available Retrofit Technology Analysis, June 6, 2007.
     PNM San Juan Generating Station, BART Analysis of SNCR, May 30, 
2008.
     PNM San Juan Generating Station, BART Analysis of Nalco Mobotec 
NOX Control Technologies, August 29, 2008.

[[Page 500]]

       Table 1--Projected NOX Control Effectiveness for Units 1-4
------------------------------------------------------------------------
                                                           Controlled
        Control technology               Control       emission rate (lb/
                                      efficiency (%)         MMbtu)
------------------------------------------------------------------------
ROFA..............................              13-15               0.26
Rotamix (SNCR)....................              23-25               0.23
ROFA/Rotamix......................              33-35               0.20
SCR/SNCR Hybrid...................              40-41               0.18
SCR...............................                 77               0.07
------------------------------------------------------------------------

iv. Evaluation of Impacts and Documentation of Results
    Under step 4 of the BART determination process, we conducted the 
following analysis of the possible impacts due to the installation of 
the technically feasible NOX control options:
     Costs of Compliance.
     Energy Impacts.
     Non-Air Quality Environmental Impacts.
     Remaining Useful Life.
    When performing BART analyses on each of the technically feasible 
NOX control options, PNM considered the energy impacts, non-
air quality environmental impacts, and the remaining useful life. PNM 
accounted for the additional cost of certain energy impacts in the cost 
impacts analysis. It did not note any other energy impacts as being 
significant. With regard to non-air quality environmental impacts, PNM 
did not identify any significant or unusual environmental impacts 
associated with the control alternatives that had the potential to 
affect the selection or elimination of that control alternative. For 
SCR and SCR/SNCR Hybrid technologies, the non-air quality environmental 
impacts included the consideration of water usage and waste generated 
from each control technology. Lastly, the remaining useful life was 
defined by PNM as 20 years. Therefore, no additional cost adjustments 
for a short remaining useful boiler life were claimed by PNM.
    PNM calculated the costs of each of the technically feasible 
NOX control options \21\. This information was assessed by 
NMED in its BART analysis. We checked that information and present it 
below in Tables 2-5 (with a few minor corrections). It summarizes our 
evaluation of the impacts of the BART analyses, including updated cost 
data for the SCR option:
---------------------------------------------------------------------------

    \21\ Tables 2-5 were constructed to incorporate costs due to 
sorbent injection, as a means of SO3 control in 
conjunction with SCR. This was done by PNM in response to a request 
by NMED. As NMED notes in its BART analysis, it understands there 
are SCR catalysts now on the market that are capable of a much 
smaller SO2 to SO3 conversion. In our own 
analysis, we have concurred with this finding and hence do not 
consider sorbent injection.

                                                     Table 2--Impact Analysis and Cost Effectiveness of NOX Control Technologies for Unit 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Total         Total                     Incremental
                       Control technology                           Emission         NOX           NOX         capital     annualized        Cost           cost         Energy        Non-air
                                                                      limit       emissions     reduction    investment    cost  (TAC)  effectiveness  effectiveness     impacts       impacts
                                                                   (lbs/MMBtu)         (tpy)         (tpy)         (TCI)      (1,000$)        ($/ton)        ($/ton)      (1,000$)      (1,000$)
                                                                                                                (1,000$)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SCR + sorbent...................................................          0.07           966         3,174       164,732        21,998          6,931          3,815         1,569        \1\ NA
SNCR/SCR Hybrid.................................................          0.18         2,484         1,656       104,436        16,207          9,787         34,221           706         1,762
ROFA/Rotamix....................................................          0.20         2,760         1,380            29         6,762          4,900          7,766         1,413             3
Rotamix (SNCR)..................................................          0.23         3,174           966        11,306         3,547          3,672            222            51             4
ROFA............................................................          0.26         3,588           552        18,293         3,455          6,259         -2,896         1,363        \1\ NA
Consent Decree..................................................          0.30         4,140         1,254        14,580         1,422          1,134             NA        \1\ NA        \1\ NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

                                                     Table 3--Impact Analysis and Cost Effectiveness of NOX Control Technologies for Unit 2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Total
                                                                     Emission         NOX           NOX         capital        Total         Cost       Incremental      Energy        Non-air
                        Control technology                             limit       emissions     reduction    investment    annualized   effectivness       cost         impacts       impacts
                                                                                                                 (TCI)      cost  (TAC)                effectiveness
                                                                    (lbs/MMBtu)         (tpy)         (tpy)      (1,000$)      (1,000$)       ($/ton)        ($/ton)      (1,000$)      (1,000$)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SCR + sorbent....................................................          0.07           961         3,158       177,178        23,364         7,399          4,432         1,565        \1\ NA
SNCR/SCR Hybrid..................................................          0.18         2,471         1,648       108,628        16,670        10,118         36,082           346         1,762
ROFA/Rotamix.....................................................          0.20         2,746         1,373        29,350         6,762         4,925          7,805         1,413             3
Rotamix (SNCR)...................................................          0.23         3,158           961        11,306         3,547         3,691            223            51             4
ROFA.............................................................          0.26         3,570           549        18,293         3,455         6,291         -1,375         1,363        \1\ NA
Consent Decree...................................................          0.30         4,119         2,060        14,126         1,378           669             NA        \1\ NA        \1\ NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

                                                     Table 4--Impact Analysis and Cost Effectiveness of NOX Control Technologies for Unit 3
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Total
                                                                    Emission         NOX        NO[ihel3]      capital        Total          Cost       Incremental      Energy        Non-air
                       Control technology                             limit       emissions     reduction    investment    annualized   effectiveness       cost         impacts       impacts
                                                                                                                (TCI)      cost  (TAC)                 effectiveness
                                                                   (lbs/MMBtu)         (tpy)         (tpy)      (1,000$)      (1,000$)        ($/ton)        ($/ton)      (1,000$)      (1,000$)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SCR + sorbent...................................................          0.07         1,501         4,930       227,774        30,527          6,192          2,087         2,267        \1\ NA

[[Page 501]]

 
SNCR/SCR Hybrid.................................................          0.18         3,859         2,572       168,507        25,606          9,954         37,221           507         2,658
ROFA/Rotamix....................................................          0.20         4,287         2,144        34,070         9,648          4,501          7,338         2,810             5
Rotamix (SNCR)..................................................          0.23         4,930         1,501        13,316         4,929          3,285           -303            84             5
ROFA............................................................          0.26         5,574           857        20,983         5,124          5,976         -2,264         2,725        \1\ NA
Consent Decree..................................................          0.30         6,431         2,573        12,715         1,240            482             NA        \1\ NA        \1\ NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

                                                     Table 5--Impact Analysis and Cost Effectiveness of NOX Control Technologies for Unit 4
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Total
                                                                    Emission         NOX           NOX         capital        Total          Cost       Incremental      Energy        Non-air
                       Control technology                             limit       emissions     reduction    investment    annualized   effectiveness       cost         impacts       impacts
                                                                                                                (TCI)      cost  (TAC)                 effectiveness
                                                                   (lbs/MMBtu)         (tpy)         (tpy)      (1,000$)      (1,000$)        ($/ton)        ($/ton)      (1,000$)      (1,000$)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SCR + sorbent...................................................          0.07         1,472         4,837       211,764        28,760          5,946          1,691         2,288        \1\ NA
SNCR/SCR Hybrid.................................................          0.18         3,785         2,524       161,572        24,849          9,847         36,141           507         2,658
ROFA/Rotamix....................................................          0.20         4,206         2,103        34,070         9,648          4,588          7,480         2,810             5
Rotamix (SNCR)..................................................          0.23         4,837         1,472        13,316         4,929          3,348           -309            84             5
ROFA............................................................          0.26         5,468           841        20,983         5,124          6,091         -2,299         2,275        \1\ NA
Consent Decree..................................................          0.30         6,309         2,524        12,870         1,256            498             NA        \1\ NA       \1\ NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ PNM performed an impact analysis for these technologies and incorporated any monetized energy or non-air environmental impacts into the cost analysis

    We find that the energy impacts, non-air quality environmental 
impacts, and the remaining useful life do not present sufficient reason 
to disqualify any of the technically feasible NOX control 
technologies.
v. Evaluation of Visibility Impacts and Cost Analysis
    Under step 5 of the BART Guidelines, we evaluate the visibility 
improvement for each feasible control technology. NMED modeled \22\ the 
visibility benefits of each of the NOX control technologies 
listed in Tables 2-5, above, on 16 Class I areas. NMED used the CALPUFF 
modeling system, which consists of a meteorological data pre-processor 
(CALMET), an air dispersion model (CALPUFF), and post-processor 
programs (POSTUTIL, CALSUM, CALPOST). The CALPUFF modeling system is 
the recommended model for conducting BART visibility analysis. First, 
the model was run using the pre-BART, consent decree conditions to 
establish a baseline. The model was then run for each of the control 
technologies identified for each unit during the BART engineering 
analysis. These visibility impacts were then compared to the baseline 
to evaluate the visibility benefit of each control. NMED modeled the 
visibility impacts of each of the control scenarios individually for 
each of the SJGS units, as well as calculated visibility impacts on a 
facility-wide basis. The NMED modeling used the original IMPROVE 
equation within CALPOST to estimate visibility impairment from the 
modeled pollutant concentrations. Table 6, below, summarizes the 
results of the latter exercise, for the maximum impacts of the 98th 
percentile delta-dv impacts from 2001-2003.
---------------------------------------------------------------------------

    \22\ NMED performed some modeling as well as reviewed modeling 
protocols and results supplied by PNM and prepared by the contractor 
Black & Veatch found in: Public Service Company of New Mexico BART 
Technology Analysis for the San Juan Generating Station (June 6, 
2007 and submittal updates). When we say ``NMED modeling'' or ``NMED 
modeled'' we are referring to the modeling performed or reviewed by 
NMED.
---------------------------------------------------------------------------

    All of the WRAP and NMED refined modeling was conducted with the 
version of the CALPUFF system recommended by the WRAP BART modeling 
protocol \23\ and followed the WRAP protocol for source-specific 
applications. As we note in the TSD, NMED and the WRAP utilized CALMET 
version 6.211 to create the necessary meteorological database for input 
into the CALPUFF model. Some technical concerns have been identified 
with this non-regulatory version of the model. The concerns are 
discussed in the technical support document. Our regulatory version of 
the model is CALMET 5.8, which we used in our modeling. Two pollutants 
must be given special consideration when estimating the impact of 
various control technologies on visibility improvement: Background 
ammonia (NH3) and sulfuric acid 
(H2SO4) emissions. NMED utilized a variable 
monthly background NH3 concentration rather than using the 
default recommended value. As discussed later, we utilized both 
approaches for background NH3 in our modeling so as to be 
able to compare the results. For estimating H2SO4 
emissions, NMED estimated the fraction of particulate matter (PM) 
emissions that are classified as inorganic condensable PM and assumed 
that 100% of this fraction is H2SO4. Additional 
H2SO4 due to SCR operation was calculated 
assuming 1% conversion of SO2 to SO3. As noted in 
the TSD and briefly described below, our approach to these two factors 
differed from the NMED approach. The results provided by NMED, and 
included in Table 6 below, demonstrate that SCR is by far the most 
advantageous approach to NOX control. The differences in our 
and New Mexico's approaches should not change the relative advantage 
that SCR has over other control methods in improving visibility since 
these concerns are present in all the NMED modeling and would have 
similar impacts on the modeling results.
---------------------------------------------------------------------------

    \23\ ``CALMET/CALPUFF Protocol for BART Exemption Screening 
Analysis for Class I Areas in the Western United States'', Western 
Regional Air Partnership (WRAP); Gail Tonnesen, Zion Wang; Ralph 
Morris, Abby Hoats and Yiqin Jia, August 15, 2006. available at 
http://pah.cert.ucr.edu/aqm/308/bart/WRAP_RMC_BART_Protocol_Aug15_2006.pdf.

[[Page 502]]

                              Table 6--NMED Modeled Maximum Impacts of the 98th Percentile delta-dv Impacts From 2001-2003
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Consent
                         Class I area                          Distance to     decree       SCR +      SCR/ SNCR      ROFA/       Rotamix        ROFA
                                                                SJGS (km)     baseline     Sorbent       Hybrid      Rotamix
--------------------------------------------------------------------------------------------------------------------------------------------------------
Arches.......................................................          222         1.69         1.10         1.58         1.58         1.61         1.63
Bandelier Wilderness.........................................          210         1.56         0.80         1.33         1.28         1.35         1.41
Black Canyon of the Gunnison Wilderness......................          203         1.15         0.63         0.94         0.93         0.98         1.04
Canyonlands..................................................          170         2.26         1.59         2.17         2.10         2.13         2.17
Capitol Reef.................................................          232         1.81         1.08         1.64         1.55         1.62         1.68
Grand Canyon.................................................          285         0.97         0.53         0.80         0.79         0.84         0.88
Great Sand Dunes National Monument...........................          269         0.71         0.40         0.64         0.60         0.61         0.65
La Garita Wilderness.........................................          169         0.94         0.45         0.78         0.74         0.79         0.83
Maroon Bells Snowmass Wilderness.............................          271         0.56         0.28         0.48         0.47         0.50         0.52
Mesa Verde...................................................           40         3.80         2.46         4.42         3.58         3.58         3.59
Pecos Wilderness.............................................          248         1.09         0.66         0.90         0.88         0.92         0.97
Petrified Forest.............................................          213         0.82         0.48         0.73         0.73         0.77         0.78
San Pedro Parks Wilderness...................................          155         2.01         1.13         1.80         1.67         1.77         1.86
West Elk Wilderness..........................................          216         0.91         0.43         0.73         0.71         0.76         0.80
Weminuche Wilderness.........................................           98         1.48         0.90         1.33         1.24         1.32         1.36
Wheeler Peak Wilderness......................................          258         0.89         0.50         0.72         0.70         0.75         0.79
                                                              ------------------------------------------------------------------------------------------
    Total....................................................  ...........        22.65        13.42        20.99        19.55        20.30        20.96
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We note NMED's modeling indicated there was little difference 
between the SCR/SNCR hybrid, ROFA/Rotamix, and ROFA NOX 
control technologies. However, as Tables 2-5 indicate, there is a 
significant difference in the cost of those controls, with the SNCR/SCR 
hybrid being more than twice as expensive as the ROFA/Rotamix, and 
approximately five times as expensive as both the Rotamix (SNCR) and 
the ROFA options. None of these NOX control technologies was 
capable of significantly improving the visibility at any of the 16 
Class I areas; therefore, we did not further evaluate them. However, we 
note that SCR was capable of uniformly improving the visibility at all 
of the 16 Class I areas, but at a higher cost.
    The costs of the controls in Tables 2-5, were calculated by PNM. 
Because we found the costs projected by PNM to be high in comparison to 
other SCR retrofits we have reviewed, we refined the cost of 
retrofitting the SJGS with SCR (see the TSD for more information), and 
the NOX emission level SCR was capable of achieving when 
retrofitted to the SJGS. This analysis indicated that the cost of SCR 
at this source would be considerably lower than calculated by PNM. We 
believe that PNM overestimated the cost of SCR due to several basic 
errors that PNM made in constructing its SCR cost analysis:
     PNM did not follow the EPA Air Pollution Control Cost 
Manual, where possible,\24\ as directed by the BART Guidelines.\25\
---------------------------------------------------------------------------

    \24\ U.S. EPA, EPA Air Pollution Control Cost Manual, Report 
EPA/452/B-02-001, 6th Ed., January 2002 (``Cost Manual''), The EPA 
Air Pollution Control Cost Manual is the current name for what was 
previously known as the OAQPS Control Cost Manual, the name for the 
Cost Manual in previous (pre-2002) editions of the Cost Manual.
    \25\ In order to maintain and improve consistency, cost 
estimates should be based on the OAQPS Control Cost Manual, where 
possible. 70 FR 39104, 39166 (2005).
---------------------------------------------------------------------------

     PNM scaled many of the cost items from another project 
that has significant design differences when compared to the SJGS. We 
made changes in many of these items to adjust them from budgetary to 
final contract; to exclude equipment and modifications not required for 
the SJGS SCR installations; to correct errors; and to factor out 
installation, freight, and other costs that were included in the 
contract awards and double counted elsewhere in PNM's cost estimate. We 
have concluded that these adjustments are correct, and provide a more 
accurate estimate of the costs at SJGS.
     PNM performed their SCR cost estimate on the basis of a 
NOX control rate of 0.07 lbs/MMBtu. We concluded that SCR 
could reliably achieve NOX control at a rate of 0.05 lbs/
MMBtu on a 30-day rolling average basis, for each of the four units of 
the SJGS. Because this did not require a change in the capital cost of 
the SCR unit, and only necessitated the purchase of additional reagent, 
this had the effect of improving the cost effectiveness. We have 
concluded that the analysis concerning the achievability of the 
emissions limit, and the cost of achieving those limits, is more 
accurate.
    The results of that analysis are presented as Table 7:

                                             Table 7--EPA Determined Cost Effectiveness of SCR for the SJGS
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               Total           Cost
                          Unit                            Emission limit   NOX emissions   NOX reduction   Total capital    annualized     effectiveness
                                                            (lbs/MMBtu)        (tpy)           (tpy)        investment         cost           ($/ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.......................................................            0.05             690           3,450     $53,230,469      $6,373,573           1,847
2.......................................................            0.05             686           3,433      55,664,049       6,591,720           1,920
3.......................................................            0.05           1,071           5,360      70,464,306       8,631,234           1,610
4.......................................................            0.05           1,051           5,258      67,223,223       8,304,143           1,579
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 503]]

    Based on our refined cost and control effectiveness analysis, we 
conclude that SCR is cost effective for all units of the SJGS.
    Although we generally regard the visibility modeling analyses 
performed by NMED to be of high quality, we noted some minor issues we 
wished to rectify in order to address consistency with modeling 
guidance we have provided to the states. We remodeled the visibility 
impacts of the SJGS using revised emission estimates and meteorology 
results from the regulatory version of the CALPUFF and CALMET models. 
As detailed in the TSD, we utilized a different approach based on the 
best current information from the Electric Power Research Institute 
(EPRI) \26\ to estimate the sulfuric acid released from combustion in 
the boiler for all scenarios and for operation of the SCR, assuming a 
0.5% SO2 to SO3 conversion efficiency \27\ of the 
SCR catalyst (compared to a 1% conversion assumed by NMED). We 
determined that the SCR could achieve an emission rate of 0.05 lb 
NOX/MMBtu and included this emission rate in modeling the 
SCR control scenario (compared to 0.07 lb NOX/MMBtu assumed 
by NMED). We modeled a revised baseline with the SO2 
emissions lowered to the BART presumptive limit of 0.15 lb/MMBtu that 
was assumed by the WRAP for regional photochemical visibility modeling 
to demonstrate reasonable progress towards natural visibility 
conditions. Finally, modeling was performed utilizing both the monthly 
variable background NH3 concentration used by NMED and the 
default background NH3 concentration of 1.0 ppb to evaluate 
the sensitivity of the results to these assumptions. Visibility 
impairment from our modeled pollutant concentrations were calculated 
using both the original IMPROVE equation (Method 6) used by NMED and 
the revised IMPROVE equation (Method 8) to calculate visibility 
impairment from the modeled pollutant concentrations.
---------------------------------------------------------------------------

    \26\ Electric Power Research Institute, Estimating Total 
Sulfuric Acid Emissions from Stationary Power Plants, 1016384 
Technical Update, March 2008.
    \27\ Emails between Anita Lee, EPA Region 9 and Anthony C. 
Favale P.E., Director--SCR Products, Hitachi Power Systems America, 
Ltd. Favale: ``Catalyst development has progressed over the last few 
years to the point that an initial SO2 conversion rate of 
0.5% can be guaranteed with 80 to 90% NOX reduction.''
---------------------------------------------------------------------------

    As Table 8 indicates, in considering the visibility impacts 
associated with the use of SCR, we focused on the 98th percentile of 
modeled results to avoid giving undue weight to any extreme 
results.\28\ The results are presented as the visibility impacts from 
SJGS and the associated changes in visibility at each Class I area 
within 300 kilometers of the facility resulting from the use of SCR. 
These results employ our revised baseline, a 1 ppb background 
NH3 concentration assumption, our revised SO2 to 
SO3 conversion calculation, and the new IMPROVE equation 
(Method 8). The other methods that we utilized in our sensitivity 
modeling approaches using Method 6 and/or the variable NH3 
are documented in the TSD.
---------------------------------------------------------------------------

    \28\ See 70 FR at 39,121.

           Table 8--EPA Modeled Maximum Impacts of the 98th Percentile delta-dv Impacts From 2001-2003
----------------------------------------------------------------------------------------------------------------
                                                                     Baseline       Visibility      Visibility
                                                    Distance to     visibility      impact with     improvement
                  Class I area                       SJGS (km)        impact            SCR          with SCR
                                                                    ([Delta]dv)     ([Delta]dv)     ([Delta]dv)
----------------------------------------------------------------------------------------------------------------
Arches..........................................             222            3.50            1.12            2.38
Bandelier Wilderness............................             210            1.39            0.48            0.91
Black Canyon of the Gunnison Wilderness.........             203            1.41            0.42            0.99
Canyonlands.....................................             170            4.64            1.53            3.11
Capitol Reef....................................             232            2.38            0.82            1.56
Grand Canyon....................................             285            0.93            0.33            0.60
Great Sand Dunes National Monument..............             269            1.53            0.49            1.04
La Garita Wilderness............................             169            1.93            0.57            1.36
Maroon Bells Snowmass Wilderness................             271            0.70            0.28            0.42
Mesa Verde......................................              40            5.15            2.27            2.88
Pecos Wilderness................................             248            1.27            0.47            0.80
Petrified Forest................................             213            0.52            0.21            0.31
San Pedro Parks Wilderness......................             155            2.20            0.74            1.46
West Elk Wilderness.............................             216            1.59            0.45            1.14
Weminuche Wilderness............................              98            2.92            0.87            2.05
Wheeler Peak Wilderness.........................             258            1.12            0.44            0.68
                                                 ---------------------------------------------------------------
    Total Delta dv..............................  ..............           33.18           11.48           21.69
----------------------------------------------------------------------------------------------------------------

    As can be seen from Table 8, our visibility modeling indicates that 
SCR NOX control offers visibility improvement at every one 
of the 16 Class I areas and significant visibility improvement at the 
overwhelming majority of areas. Therefore, after having identified all 
available retrofittable NOX control technologies, eliminated 
those that were not technically feasible, evaluated the NOX 
control effectiveness of those remaining, evaluated the impacts and 
having documented the results, we propose that NOX BART for 
all the units of the SJGS is SCR with a 30 day rolling average of 0.05 
lbs/MMBtu.
    In addition, our visibility analysis relied in part on estimates of 
H2SO4 mist emissions. The amount of 
H2SO4 emissions depends, in part, on proper 
design and operation of the SCR unit. Therefore, we believe it is 
appropriate to set emission limits for H2SO4. We 
believe that our estimates of these emissions are appropriate based on 
the use of low reactivity catalyst that will reduce the rate of 
SO2 to SO3 conversion. To ensure these levels are 
met, we are proposing that emissions of H2SO4 be 
limited to 1.06 x 10-4 lb/MMBtu for each unit. These 
emission limits are based on the most current information from the 
Electric Power Research Institute (EPRI), information on the sulfur 
content of the coal, and assuming a maximum of 0.5% SO2 to 
SO3 conversion efficiency of the SCR catalyst. We note that 
there is some potential variation in the methodologies

[[Page 504]]

and the assumptions used method for calculating 
H2SO4 emissions. The assumptions associated with 
our calculation are discussed further in the TSD. We are soliciting 
comment on setting the emission limit in the range between our proposed 
limit of 1.06 x 10-4 lb/MMBtu and an upper range of sulfuric 
acid mist emissions of 7.87 x 10-4 lb/MMBtu.\29\ Comments on 
our proposed H2SO4 limit and alternative limits 
should include consideration of the use of a low conversion rate SCR 
catalyst and be sufficiently justified.
---------------------------------------------------------------------------

    \29\ Upper range value is based on information from PNM's Toxics 
Release Inventory report and previous PNM calculations of the amount 
of additional H2SO4 from the installation and 
operation of SCR. For details on the derivation of this upper bound 
value, see the TSD.
---------------------------------------------------------------------------

    As there are no continuous emission monitoring techniques for 
H2SO4 mist, we are proposing that compliance be 
based on an hourly average, confirmed by annual stack testing using EPA 
Test Method 8A (CTM-013).\30\ We note that our proposed limits 
challenge the detection limits of the test method. We solicit comment 
on this issue, including suggestions for test methods that will better 
measure these low concentrations and other approaches to determine 
continuous compliance.
---------------------------------------------------------------------------

    \30\ http://www.epa.gov/ttn/emc/ctm/ctm-013.pdf.
---------------------------------------------------------------------------

    Similarly, our visibility analysis also relied in part on estimates 
of ammonia (NH3) slip, emissions of NH3 that pass 
through the SCR. NH3 contribute to visibility impairment. 
Limiting NH3 emissions depends on proper design and 
operation of the SCR. Therefore, we are proposing to set a limit to 
minimize the contribution of NH3 to visibility impairment. 
We are proposing that emissions of NH3 be limited to 2.0 
parts per million volume dry (ppmvd), adjusted to 6 percent oxygen for 
each of the four SJGS units.\31\ We are also soliciting comment on 
setting this limit in the range of 2-6 ppmvd, adjusted to 6 percent 
oxygen. Comments on our proposed limit and alternative limits should 
consider visibility impairment. Compliance will be based on an hourly 
average confirmed by an initial performance test using EPA Conditional 
Test Method 27 (40 CFR 51, Appendix M). We are also proposing that a 
CEM for NH3 be installed and operated. We solicit comment on 
other approaches to determine continuous compliance.
---------------------------------------------------------------------------

    \31\ PNM materials previously indicated that a 2 ppm ammonia 
slip limit would be appropriate for SCR at the Public Service 
Company of New Mexico Black and Veatch report titled: ``San Juan 
Generating Station Best Available Retrofit Technology Analysis'' 
Issue Date and Revision June 6, 2007, Final; Appendix B, page B-3.
---------------------------------------------------------------------------

    As we note above in section II.B.3, the RHR requires that BART 
controls must be installed and in operation as expeditiously as 
practicable, but no later than five (5) years after the date of our 
approval of the RH SIP. 40 CFR 51.308(e)(1)(iv). Based on the retrofit 
of other SCR installations we have reviewed, we find that three (3) 
years from the date our final determination becomes effective is a 
conservative and adequate estimate of time for the planning, 
engineering, installation, and start-up of these controls.\32\ Many 
installations have been completed in much shorter times.\33\ We solicit 
comment on alternative timeframes, up to five (5) years from the date 
our final determination becomes effective.
---------------------------------------------------------------------------

    \32\ Typical Installation Timelines for NOx Emissions Control 
Technologies on Industrial Sources, Institute of Clean Air 
Companies, December 4, 2006, available at http://www.icac.7com/files/public/ICAC_NOx_Control_Installation_Timing_120406.pdf; 
see also Engineering and Economic Factors Affecting the Installation 
of Control Technologies for Multipollutant Strategies, EPA-600/R-02/
073, October 2002, available at http://www.epa.gov/clearskies/pdfs/multi102902.pdf.
    \33\ Id.
---------------------------------------------------------------------------

IV. Proposed Action

    We are proposing to disapprove a portion of the SIP revision 
submitted by the State of New Mexico for the purpose of addressing the 
``good neighbor'' provisions of the CAA section 110(a)(2)(D)(i) for the 
1997 8-hour ozone NAAQS and the PM2.5 NAAQS. We are 
proposing to disapprove the New Mexico Interstate Transport SIP 
provisions 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 
protect visibility. As a result of the proposed disapproval, we are 
also proposing a FIP to address the requirements of section 
110(a)(2)(D)(i)(II) with respect to visibility. With regard to whether 
emissions from New Mexico sources interfere with the visibility 
programs of other states, we are proposing to find that New Mexico 
sources, except the SJGS, are sufficiently controlled to eliminate 
interference with the visibility programs of other states, and for the 
SJGS source we are proposing to impose specific SO2 and 
NOX emissions limits that will eliminate such interstate 
interference. In addition, EPA is proposing the FIP to address the 
requirement for BART for NOX for the SJGS.
    Based on our evaluation we are proposing to find that the SJGS is 
subject to BART under section 40 CFR 51.309(d)(4), and/or 51.308(e). 
Our proposed NOX controls for SJGS will partially address 
the BART requirements of the RH program. Specifically, we are proposing 
a FIP that imposes NOX BART limits for the SJGS. Together, 
the reduction in NOX from our proposed NOX BART 
determination, and the proposed SO2 emission limits will 
serve to ensure there are enforceable mechanisms in place to prevent 
New Mexico NOX and SO2 emissions from interfering 
with efforts to protect visibility in other states pursuant to the 
requirements of section 110(a)(2)(D)(i)(II) of the CAA.
    For NOX emissions, we are proposing to require the SJGS 
to meet an emission limit of 0.05 pounds per million British Thermal 
Units (lb/MMBtu) individually at Units 1, 2, 3, and 4. This 
NOX limit is achievable by installing and operating SCR. For 
SO2, we are proposing to require the SJGS to meet an 
emission limit of 0.15 lb/MMBtu. Both of these emission limits would be 
measured on the basis of a 30 day rolling average. We are also 
proposing hourly average emission limits of 1.06 x 10-4 lb/
MMBtu for H2SO4 and 2.0 ppmvd, for 
NH3, to minimize the contribution of these compounds to 
visibility impairment. Additionally, we are proposing monitoring, 
recordkeeping and reporting requirements to ensure compliance with 
emission limitations.
    We also propose that compliance with the emission limits be within 
three (3) years of the effective date of our final rule. We solicit 
comments on alternative timeframes, up to five (5) years from the 
effective date our final rule.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This proposed action is not a ``significant regulatory action'' 
under the terms of Executive Order (EO) 12866, (58 FR 51735, October 4, 
1993), and is therefore not subject to review under the Executive 
Order. This action proposes a source-specific FIP for the San Juan 
Power Generating Station (SJGS) in New Mexico.

B. Paperwork Reduction Act

    This proposed action does not impose an information collection 
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. Under the Paperwork Reduction Act, a ``collection of 
information'' is defined as a requirement for ``answers to * * * 
identical reporting or recordkeeping requirements imposed on ten or 
more persons * * *.'' 44 U.S.C. 3502(3)(A). Because the proposed FIP 
applies to a single facility, (SJGS), the Paperwork

[[Page 505]]

Reduction Act does not apply. See 5 CFR 1320(c).
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute 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 organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of today's proposed rule on 
small entities, small entity is defined as: (1) A small business as 
defined by the Small Business Administration's (SBA) regulations at 13 
CFR 121.201; (2) a small governmental jurisdiction that is a government 
of a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of this proposed action on 
small entities, I certify that this proposed action will not have a 
significant economic impact on a substantial number of small entities. 
The FIP for SJGS being proposed today does not impose any new 
requirements on small entities. See Mid-Tex Electric Cooperative, Inc. 
v. FERC, 773 F.2d 327 (D.C. Cir. 1985).

D. Unfunded Mandates Reform Act (UMRA)

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and Tribal 
governments and the private sector. Under section 202 of UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more 
(adjusted to inflation) in any 1 year. Before promulgating an EPA rule 
for which a written statement is needed, section 205 of UMRA generally 
requires EPA to identify and consider a reasonable number of regulatory 
alternatives and adopt the least costly, most cost-effective, or least 
burdensome alternative that achieves the objectives of the rule. The 
provisions of section 205 of UMRA do not apply when they are 
inconsistent with applicable law. Moreover, section 205 of UMRA allows 
EPA to adopt an alternative other than the least costly, most cost-
effective, or least burdensome alternative if the Administrator 
publishes with the final rule an explanation why that alternative was 
not adopted. Before EPA establishes any regulatory requirements that 
may significantly or uniquely affect small governments, including 
Tribal governments, it must have developed under section 203 of UMRA a 
small government agency plan. The plan must provide for notifying 
potentially affected small governments, enabling officials of affected 
small governments to have meaningful and timely input in the 
development of EPA regulatory proposals with significant Federal 
intergovernmental mandates, and informing, educating, and advising 
small governments on compliance with the regulatory requirements.
    Under Title II of UMRA, EPA has determined that this proposed rule 
does not contain a Federal mandate that may result in expenditures that 
exceed the inflation-adjusted UMRA threshold of $100 million by State, 
local, or Tribal governments or the private sector in any 1 year. In 
addition, this proposed rule does not contain a significant Federal 
intergovernmental mandate as described by section 203 of UMRA nor does 
it contain any regulatory requirements that might significantly or 
uniquely affect small governments.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It 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. This action merely prescribes EPA's 
action to address the State not fully meeting its obligation to 
prohibit emissions from interfering with other states measures to 
protect visibility. Thus, Executive Order 13132 does not apply to this 
action. In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000). 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 proposed rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    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 proposed rule is not subject to Executive Order 13045 because 
it limits emissions of pollutants from an existing single stationary 
source. Because this proposed action only applies to a single existing 
source and is not a proposed rule of general applicability, it is not

[[Page 506]]

economically significant as defined under Executive Order 12866, and 
does not have a disproportionate effect on children. However, to the 
extent that the rule will limit emissions of NOX and 
SO2 the rule will have a beneficial effect on children's 
health by reducing air pollution.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 (66 FR 28355 
(May 22, 2001)), because it is not a significant regulatory action 
under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. NTTAA directs EPA to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards. This proposed 
rule would require all sources to meet the applicable monitoring 
requirements of 40 CFR part 75. Part 75 already incorporates a number 
of voluntary consensus standards. Consistent with the Agency's 
Performance Based Measurement System (PBMS), part 75 sets forth 
performance criteria that allow the use of alternative methods to the 
ones set forth in part 75. The PBMS approach is intended to be more 
flexible and cost effective for the regulated community; it is also 
intended to encourage innovation in analytical technology and improved 
data quality. At this time, EPA is not recommending any revisions to 
part 75; however, EPA periodically revises the test procedures set 
forth in part 75. When EPA revises the test procedures set forth in 
part 75 in the future, EPA will address the use of any new voluntary 
consensus standards that are equivalent. Currently, even if a test 
procedure is not set forth in part 75, EPA is not precluding the use of 
any method, whether it constitutes a voluntary consensus standard or 
not, as long as it meets the performance criteria specified; however, 
any alternative methods must be approved through the petition process 
under 40 CFR 75.66 before they are used.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994), establishes 
federal executive policy on environmental justice. Its main provision 
directs Federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this proposed rule, if finalized, will not 
have disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it increases the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population. This proposed rule limits emissions of pollutants 
from a single stationary source, SJGS.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Particulate matter, Reporting and 
recordkeeping requirements, Sulfur dioxide, Visibility, Interstate 
transport of pollution, Regional haze, Best available control 
technology.

    Dated: December 20, 2010.
Samuel J. Coleman,
Acting Regional Administrator, Region 6.

    Title 40, chapter I, of the Code of Federal Regulations is proposed 
to be amended as follows:

PART 52--[AMENDED]

    1. The authority citation for part 52 continues to read as follows:

    Authority:  42 U.S.C. 7401 et seq.

    2. Add Sec.  52.1628 to read as follows:

Sec.  52.1628  Interstate pollutant transport and regional haze 
provisions; What are the FIP requirements for San Juan Generating 
Station emissions affecting visibility?

    (a) Applicability. The provisions of this section shall apply to 
each owner or operator of the coal burning equipment designated as 
Units 1, 2, 3, or 4 at the San Juan Generating Station in San Juan 
County, New Mexico (the plant).
    (b) Compliance dates. Compliance with the requirements of this 
section is required upon the effective date of this rule unless 
otherwise indicated by compliance dates contained in specific 
provisions.
    (c) Definitions. All terms used in this part but not defined herein 
shall have the meaning given them in the Clean Air Act and in parts 51 
and 60 of this chapter. For the purposes of this section:
    24-hour period means the period of time between 12:01 a.m. and 12 
midnight.
    Air pollution control equipment includes baghouses, particulate or 
gaseous scrubbers, and any other apparatus utilized to control 
emissions of regulated air contaminants which would be emitted to the 
atmosphere.
    Daily average means the arithmetic average of the hourly values 
measured in a 24-hour period.
    Heat input means heat derived from combustion of fuel in a Unit and 
does not include the heat input from preheated combustion air, 
recirculated flue gases, or exhaust gases from other sources. Heat 
input shall be calculated in accordance with 40 CFR part 75.
    Owner or Operator means any person who owns, leases, operates, 
controls, or supervises the plant or any of the coal burning equipment 
designated as Units 1, 2, 3, or 4 at the plant.
    Oxides of nitrogen (NOX) means all oxides of nitrogen except 
nitrous oxide, as measured by test methods set forth in 40 CFR part 60.
    Regional Administrator means the Regional Administrator of EPA 
Region 6 or his/her authorized representative.
    (d) Emissions limitations and control measures. (1) Within 180 days 
of the effective date of this paragraph (d), the owner or operator 
shall submit a plan to the Regional Administrator that identifies the 
air pollution control equipment and schedule for complying with 
paragraph (d) of this section. The owner or operator shall submit 
amendments to the plan to the Regional Administrator as changes occur. 
The NOX and SO2 limits shall be effective no 
later than 3 years after the effective date of this rule. No owner or 
operator shall discharge or cause the discharge of NOX or 
SO2 into the atmosphere from Units 1, 2, 3 and 4 in excess 
of the limits for these pollutants.
    (2) NOX emission limit. The NOX limit for each unit in 
the plant, expressed as nitrogen dioxide (NO2), shall be 
0.05 pounds per million British thermal

[[Page 507]]

units (lb/MMBtu) as averaged over a rolling 30 calendar day period. For 
each unit, NOX emissions for each calendar day shall be 
determined by summing the hourly emissions measured in pounds of 
NOX. For each unit, heat input for each calendar day shall 
be determined by adding together all hourly heat inputs, in millions of 
BTU. Each day the thirty-day rolling average for a unit shall be 
determined by adding together the pounds of NOX from that 
day and the preceding 29 days and dividing the total pounds of 
NOX by the sum of the heat input during the same 30-day 
period. The result shall be the 30-day rolling average in terms of lb/
MMBtu emissions of NOX. If a valid NOX pounds per 
hour or heat input is not available for any hour for a unit, that heat 
input and NOX pounds per hour shall not be used in the 
calculation of the 30-day rolling average for NOX.
    (3) SO2 emission limit. The sulfur dioxide emission limit for each 
unit shall be 0.15 lb/MMBtu as averaged over a rolling 30-calendar-day 
period. For each unit, SO2 emissions for each calendar day 
shall be determined by summing the hourly emissions measured in pounds 
of sulfur dioxide. For each unit, heat input for each calendar day 
shall be determined by adding together all hourly heat inputs, in 
millions of BTU. Each day the thirty-day rolling average shall be 
determined by adding together pounds of sulfur dioxide from that day 
and the preceding 29 days and dividing the total pounds of sulfur 
dioxide by the sum of the heat input during the same 30-day period. The 
results shall be the 30-day rolling average for lb/MMBtu emissions of 
SO2. If a valid SO2 pounds per hour or heat input 
is not available for any hour for a unit, that heat input and SO2 
pounds per hour shall not be used in the calculation of the 30-day 
rolling average for SO2.
    (4) H2SO4 emission limit: Emissions of 
H2SO4 from each unit shall be limited to 1.06 x 
10-4 lb/MMBtu on an hourly basis.
    (5) Ammonia emission limit: Emissions of ammonia (NH3) 
from each unit will be limited to 2.0 parts per million by volume, dry 
(ppmvd), adjusted to 6 percent oxygen, on an hourly average basis.
    (e) Testing and monitoring. (1) On and after the effective date of 
this regulation, the owner or operator shall install, calibrate, 
maintain and operate Continuous Emissions Monitoring Systems (CEMS) for 
NOX, SO2, and NH3 on Units 1, 2, 3, 
and 4 in accordance with 40 CFR 60.8 and 60.13(e), (f), and (h), and 
Appendix B of Part 60. The owner or operator shall comply with the 
quality assurance procedures for CEMS found in 40 CFR part 75. 
Compliance with the emission limits for NOX, SO2 
and NH3 shall be determined by using data from a CEMS.
    (2) Continuous emissions monitoring shall apply during all periods 
of operation of the coal burning equipment, including periods of 
startup, shutdown, and malfunction, except for CEMS breakdowns, 
repairs, calibration checks, and zero and span adjustments. Continuous 
monitoring systems for measuring SO2, NOX, 
NH3 and diluent gas shall complete a minimum of one cycle of 
operation (sampling, analyzing, and data recording) for each successive 
15-minute period. Hourly averages shall be computed using at least one 
data point in each fifteen minute quadrant of an hour. Notwithstanding 
this requirement, an hourly average may be computed from at least two 
data points separated by a minimum of 15 minutes (where the unit 
operates for more than one quadrant in an hour) if data are unavailable 
as a result of performance of calibration, quality assurance, 
preventive maintenance activities, or backups of data from data 
acquisition and handling system, and recertification events. When valid 
SO2 pounds per hour, NOX pounds per hour, 
SO2 pounds per million Btu emission data, NOX 
pounds per million Btu emission data, or NH3 ppmvd data are 
not obtained because of continuous monitoring system breakdowns, 
repairs, calibration checks, or zero and span adjustments, emission 
data must be obtained by using other monitoring systems approved by the 
EPA to provide emission data for a minimum of 18 hours in each 24 hour 
period and at least 22 out of 30 successive boiler operating days.
    (3) Emissions of H2SO4 shall be measured 
within 180 days of start up of the NOX control device and 
annually thereafter using EPA Test Method 8A (CTM-013).
    (4) Emissions of ammonia shall be measured within 180 days of 
startup of the NOX control device using EPA Conditional Test 
Method 27.
    (5) The facility shall install, calibrate, maintain, and operate a 
CEMS to measure and record the concentrations of NH3.
    (f) Reporting and recordkeeping requirements. Unless otherwise 
stated all requests, reports, submittals, notifications, and other 
communications to the Regional Administrator required by this section 
shall be submitted, unless instructed otherwise, to the Director, 
Multimedia Planning and Permitting Division, U.S. Environmental 
Protection Agency, Region 6, to the attention of Mail Code: 6PD, at 
1445 Ross Avenue, Suite 1200, Dallas, Texas 75202-2733. For each unit 
subject to the emissions limitation in this section and upon completion 
of the installation of CEMS as required in this section, the owner or 
operator shall comply with the following requirements:
    (1) For each emissions limit in this section, comply with the 
notification and recordkeeping requirements for CEMS compliance 
monitoring in 40 CFR 60.7(c) and (d).
    (2) For each day, provide the total NOX and 
SO2 emitted that day by each emission unit. For any hours on 
any unit where data for hourly pounds or heat input is missing, 
identify the unit number and monitoring device that did not produce 
valid data that caused the missing hour.
    (g) Equipment operations. At all times, including periods of 
startup, shutdown, and malfunction, the owner or operator shall, to the 
extent practicable, maintain and operate the Plant including associated 
air pollution control equipment in a manner consistent with good air 
pollution control practices for minimizing emissions. Determination of 
whether acceptable operating and maintenance procedures are being used 
will be based on information available to the Regional Administrator 
which may include, but is not limited to, monitoring results, review of 
operating and maintenance procedures, and inspection of the Plant.
    (h) Enforcement. (1) Notwithstanding any other provision in this 
implementation plan, any credible evidence or information relevant as 
to whether the Plant would have been in compliance with applicable 
requirements if the appropriate performance or compliance test had been 
performed, can be used to establish whether or not the owner or 
operator has violated or is in violation of any standard or applicable 
emission limit in the plan.
    (2) Emissions in excess of the level of the applicable emission 
limit or requirement that occur due to a malfunction shall constitute a 
violation of the applicable emission limit.

[FR Doc. 2010-33106 Filed 1-4-11; 8:45 am]
BILLING CODE 6560-50-P