[Federal Register Volume 82, Number 96 (Friday, May 19, 2017)]
[Proposed Rules]
[Pages 22936-22949]
[FR Doc No: 2017-10108]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2017-0129; FRL-9961-28-Region 6]

Approval and Promulgation of Implementation Plans; Louisiana;
Regional Haze State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the
Environmental Protection Agency (EPA) is proposing to approve a portion
of a revision to the Louisiana State Implementation Plan (SIP)
submitted by the State of Louisiana through the Louisiana Department of
Environmental Quality (LDEQ) on February 10, 2017, that addresses
regional haze requirements for the first planning period. LDEQ
submitted this SIP revision to address deficiencies identified by the
EPA in a previous action. The EPA is proposing to approve the majority
of the SIP revision, which addresses the CAA requirement that certain
categories of existing major stationary sources built between 1962 and
1977 procure and install the Best Available Retrofit Technology (BART),
while deferring action on LDEQ's BART determination for a single
facility. Specifically, the EPA is proposing to approve most of LDEQ's
BART evaluations and conclusions for Louisiana's BART-eligible electric
generating unit (EGU) sources and to approve LDEQ's sulfur-dioxide
(SO2) and particulate-matter (PM) emission limits for those
sources that are subject to BART. The EPA is also proposing to approve
Louisiana's reliance on the Cross-State Air Pollution Rule (CSAPR)
trading program for ozone-season nitrogen oxides (NOX) as a
permissible alternative to source-specific NOX BART emission
limits. This action is being taken under sections 110 and 169A of the
CAA.

DATES: Written comments must be received on or before June 19, 2017.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2017-0129, at http://www.regulations.gov or via email to
<EMAIL_ADDRESS>Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
Regulations.gov. The EPA may publish any comment received to its public
docket. Do not submit electronically any information

you consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia
submissions (audio, video, etc.) must be accompanied by a written
comment. The written comment is considered the official comment and
should include discussion of all points you wish to make. The EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e. on the web, cloud, or other file sharing
system). For additional submission methods, please contact Jennifer
Huser<EMAIL_ADDRESS>For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Docket: The index to the docket for this action is available
electronically at www.regulations.gov and in hard copy at the EPA
Region 6, 1445 Ross Avenue, Suite 700, Dallas, Texas. While all
documents in the docket are listed in the index, some information may
be publicly available only at the hard copy location (e.g., copyrighted
material), and some may not be publicly available at either location
(e.g., CBI).

FOR FURTHER INFORMATION CONTACT: Jennifer Huser,<PHONE_NUMBER>,
<EMAIL_ADDRESS>To inspect the hard copy materials, please
schedule an appointment with Jennifer Huser or Mr. Bill Deese at 214-
665-7253.

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

Table of Contents

I. Background
    A. The Regional Haze Program
    B. Our Previous Actions on Louisiana Regional Haze
    C. CSAPR as an Alternative to Source-Specific NOX
BART
II. Our Evaluation of Louisiana's BART Analysis
    A. Identification of BART-Eligible Sources
    B. Evaluation of Which Sources Are Subject to BART
    C. Sources That Are No Longer in Operation
    D. Sources That Screened Out of BART
    1. Visibility Impairment Threshold
    2. Model Plant Analysis
    3. CALPUFF Modeling To Screen Out Sources
    E. Subject to BART Sources
    1. Reliance on CSAPR To Satisfy NOX BART
    2. Sources That Deferred a Five-Factor Analysis Due to a Change
in Operation
    3. Louisiana's Five-Factor Analyses for SO2 and PM
BART
    a. Cleco Brame Energy Center
    b. Entergy Little Gypsy
    c. Entergy Ninemile Point
    d. Entergy Waterford
III. Proposed Action
IV. Statutory and Executive Order Reviews

I. Background

A. The Regional Haze Program

    Regional haze is visibility impairment that is produced by a
multitude of sources and activities that are located across a broad
geographic area and emit fine particulates (PM2.5) (e.g.,
sulfates, nitrates, organic carbon (OC), elemental carbon (EC), and
soil dust), and their precursors (e.g., sulfur dioxide
(SO2), nitrogen oxides (NOX), and in some cases,
ammonia (NH3) and volatile organic compounds (VOCs)). Fine
particle precursors react in the atmosphere to form PM2.5,
which impairs visibility by scattering and absorbing light. Visibility
impairment reduces the clarity, color, and visible distance that can be
seen. PM2.5 can also cause serious adverse health effects
and mortality in humans; it also contributes to environmental effects
such as acid deposition and eutrophication.
    Data from the existing visibility monitoring network, ``Interagency
Monitoring of Protected Visual Environments'' (IMPROVE), shows that
visibility impairment caused by air pollution occurs virtually all the
time at most national parks and wilderness areas. In 1999, the average
visual range in many Class I areas (i.e., national parks and memorial
parks, wilderness areas, and international parks meeting certain size
criteria) in the western United States was 100-150 kilometers, or about
one-half to two-thirds of the visual range that would exist without
anthropogenic air pollution. In most of the eastern Class I areas of
the United States, the average visual range was less than 30
kilometers, or about one-fifth of the visual range that would exist
under estimated natural conditions. CAA programs have reduced some
haze-causing pollution, lessening some visibility impairment and
resulting in partially improved average visual ranges.
    CAA requirements to address the problem of visibility impairment
continue to be implemented. 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, man-made impairment of visibility in 156
national parks and wilderness areas designated as mandatory Class I
Federal areas. On December 2, 1980, EPA 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.'' These regulations
represented the first phase in addressing visibility impairment. EPA
deferred action on regional haze that emanates from a variety of
sources until monitoring, modeling, and scientific knowledge about the
relationships between pollutants and visibility impairment were
improved.
    Congress added section 169B to the CAA in 1990 to address regional
haze issues, and EPA promulgated regulations addressing regional haze
in 1999. The Regional Haze Rule revised the existing visibility
regulations to add provisions addressing regional haze impairment and
established a comprehensive visibility protection program for Class I
areas. The requirements for regional haze, found at 40 CFR 51.308 and
51.309, are included in our visibility protection regulations at 40 CFR
51.300-309. The requirement to submit a regional haze SIP applies to
all 50 states, the District of Columbia, and the Virgin Islands. States
were required to submit the first implementation plan addressing
regional haze visibility impairment no later than December 17, 2007.
    Section 169A of the CAA directs states to evaluate the use of
retrofit controls at certain larger, often under-controlled, older
stationary sources in order to address visibility impacts from these
sources. Specifically, section 169A(b)(2)(A) of the CAA requires states
to revise their SIPs to contain such measures as may be necessary to
make reasonable progress toward 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'' (BART). Larger ``fossil-fuel
fired steam electric plants'' are one of these source categories. Under
the Regional Haze Rule, states are directed to conduct BART
determinations for ``BART-eligible'' sources that may be anticipated to
cause or contribute to any visibility impairment in a Class I area. The
evaluation of BART for electric generating units (EGUs) that are
located at fossil-fuel fired power plants having a generating capacity
in excess of 750 megawatts must follow the ``Guidelines for BART
Determinations Under the Regional Haze Rule'' at appendix Y to 40 CFR
part 51 (hereinafter referred to as the ``BART Guidelines''). Rather
than

requiring source-specific BART controls, states also have the
flexibility to adopt an emissions trading program or other alternative
program as long as the alternative provides for greater progress
towards improving visibility than BART.

B. Our Previous Actions on Louisiana Regional Haze

    On June 13, 2008, Louisiana submitted a SIP to address regional
haze (2008 Louisiana Regional Haze SIP or 2008 SIP revision). We acted
on that submittal in two separate actions. Our first action was a
limited disapproval \1\ because of deficiencies in the state's regional
haze SIP submittal arising from the remand by the U.S. Court of Appeals
for the District of Columbia of the Clean Air Interstate Rule (CAIR).
Our second action was a partial limited approval/partial disapproval
\2\ because the 2008 SIP revision met some but not all of the
applicable requirements of the CAA and our regulations as set forth in
sections 169A and 169B of the CAA and 40 CFR 51.300-308, but as a
whole, the 2008 SIP revision strengthened the SIP. On August 11, 2016,
Louisiana submitted a SIP revision to address the deficiencies related
to BART for four non-EGU facilities. We proposed to approve that
revision on October 27, 2016.\3\ On February 10, 2017, Louisiana
submitted a SIP revision intended to address the deficiencies related
to BART for EGU sources (2017 Louisiana Regional Haze SIP or 2017 SIP
revision), a portion of which is the subject of this proposed action.
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    \1\ 77 FR 33642 (June 7, 2012).
    \2\ 77 FR 39425 (July 3, 2012).
    \3\ 81 FR 74750 (October 27, 2016).
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C. CSAPR as an Alternative to Source-Specific NOX BART

    In 2005, the EPA published CAIR, which required 28 states and the
District of Columbia to reduce emissions of SO2 and
NOX that significantly contribute to or interfere with
maintenance of the 1997 national ambient air quality standards (NAAQS)
for fine particulates and/or 8-hour ozone in any downwind state.\4\ EPA
demonstrated that CAIR would achieve greater reasonable progress toward
the national visibility goal than would BART; and therefore, states
could rely on CAIR as an alternative to EGU BART for SO2 and
NOX.\5\
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    \4\ 70 FR 25161 (May 12, 2005).
    \5\ 70 FR 39104, 39139 (July 6, 2005).
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    Louisiana's 2008 Regional Haze SIP relied on participation in CAIR
as an alternative to meeting the source-specific EGU BART requirements
for SO2 and NOX.\6\ Shortly after Louisiana
submitted its SIP to us, however, the D.C. Circuit remanded CAIR
(without vacatur).\7\ The court thereby left CAIR and CAIR Federal
Implementation Plans (FIPs) in place in order to ``temporarily preserve
the environmental values covered by CAIR'' until we could, by
rulemaking, replace CAIR consistent with the court's opinion.\8\ In
2011, we promulgated the Cross-State Air Pollution Rule (CSAPR) to
replace CAIR.\9\ While EGUs in Louisiana were required to participate
in CAIR for both SO2 and NOX, Louisiana EGUs are
only included in CSAPR for ozone-season NOX.\10\
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    \6\ See 40 CFR 51.308(e)(4) (2006).
    \7\ The court decided to vacate CAIR on July 11, 2008, and
revised its decision, so as to remand the rule without vacatur, on
December 23, 2008. North Carolina v. EPA, 531 F.3d 896, 901 (D.C.
Cir. 2008), modified, 550 F.3d 1176 (D.C. Cir. 2008). Louisiana's
initial Regional Haze SIP was submitted on June 13, 2008. 77 FR
39425.
    \8\ 550 F.3d at 1178.
    \9\ 76 FR 48207 (August 8, 2011).
    \10\ 76 FR 82219, at 82226 (December 30, 2011).
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    In 2012, we issued a limited disapproval of Louisiana's and several
other states' regional haze SIPs because of reliance on CAIR as an
alternative to EGU BART for SO2 and/or NOX.\11\
We also determined that CSAPR would provide for greater reasonable
progress than BART and amended the Regional Haze Rule to allow CSAPR
participation as an alternative to source-specific SO2 and/
or NOX BART for EGUs, on a pollutant-specific basis.\12\
Because Louisiana EGUs are included in CSAPR for NOX,
Louisiana can rely on CSAPR better than BART for NOX.
However, Louisiana's regional haze program must include source-by-
source EGU BART demonstrations for all other visibility impairing
pollutants, namely, SO2 and PM.
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    \11\ The limited disapproval triggered the EPA's obligation to
issue a FIP or approve a SIP revision to correct the relevant
deficiencies within 2 years of the final limited disapproval action.
CAA section 110(c)(1); 77 FR 33642, at 33654 (August 6, 2012).
    \12\ While that rulemaking also promulgated FIPs for several
states to replace reliance on CAIR with reliance on CSAPR as an
alternative to BART, it did not include a FIP for Louisiana. 77 FR
33642, 33654.
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    CSAPR has been subject to extensive litigation, and on July 28,
2015, the D.C. Circuit issued a decision generally upholding CSAPR but
remanding without vacating the CSAPR emissions budgets for a number of
states.\13\ We are in the process of responding to the remand of these
CSAPR budgets. On October 26, 2016, we finalized an update to the CSAPR
rule that addresses the 1997 ozone NAAQS portion of the remand and the
CAA requirements addressing interstate transport for the 2008 ozone
NAAQS.\14\ Additionally, three states, Alabama, Georgia, and South
Carolina, have adopted or committed to adopt SIPs to replace the
remanded FIPs and will continue the states' participation in the CSAPR
program on a voluntary basis with the same budgets. On November 10,
2016, we proposed a rule intended to address the remainder of the
court's remand as it relates to Texas.\15\ This separate proposed rule
includes an assessment of the impacts of the set of actions that the
EPA has taken or expects to take in response to the D.C. Circuit's
remand on our 2012 demonstration that participation in CSAPR provides
for greater reasonable progress than BART. Based on that assessment,
the EPA proposed that states may continue to rely on CSAPR as being
better than BART on a pollutant-specific basis.
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    \13\ Louisiana's ozone season NOX budgets were not
included in the remand. EME Homer City Generation v. EPA, 795 F.3d
118, 138 (D.C. Cir. 2015).
    \14\ 81 FR74504 (October 26, 2016).
    \15\ 81 FR 78954 (November 10, 2016).
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II. Our Evaluation of Louisiana's BART Analysis

A. Identification of BART-Eligible Sources

    In our partial disapproval and partial limited approval of the 2008
Louisiana Regional Haze SIP, we approved LDEQ's identification of 76
BART-eligible sources.\16\ Table 1 lists the EGU sources that were
identified in the 2008 Louisiana Regional Haze SIP submittal as BART-
eligible.
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    \16\ See 77 FR 11839 at 11848 (February 28, 2012).

                              Table 1--Identification of BART-Eligible EGU Sources
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              Facility name                            Units                              Parish
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Cleco Rodemacher/Brame...................  Nesbitt I (Unit 1),           Rapides.
                                            Rodemacher II (Unit 2).

Cleco Teche..............................  Unit 3......................  St. Mary.
Entergy Sterlington......................  Unit 7......................  Ouachita.
Entergy Michoud..........................  Units 2 and 3...............  Orleans.
Entergy Waterford........................  Units 1, 2, and auxiliary     St. Charles.
                                            boiler.
Entergy Willow Glen......................  Units 2, 3, 4, 5, auxiliary   Iberville.
                                            boiler.
Entergy Ninemile Point...................  Units 4 and 5...............  Jefferson.
Entergy Nelson *.........................  Units 4, 6, and auxiliary     Calcasieu.
                                            boiler.
Entergy Little Gypsy.....................  Units 2, 3, and auxiliary     St. Charles.
                                            boiler.
Louisiana Generating (NRG) Big Cajun I...  Units 1 and 2...............  Point Coupee.
Louisiana Generating (NRG) Big Cajun II..  Units 1 and 2...............  Point Coupee.
Louisiana Energy and Power Authority       Boilers 1 and 2.............  Iberville.
 Plaquemine Steam Plant.
Louisiana Energy and Power Authority       Units 1, 2, 3, and 4 boilers  St. Mary/St. Martin.
 Morgan City Steam Plant.
City of Ruston--Ruston Electric            Boilers 1, 2, and 3.........  Lincoln.
 Generating Plant.
Lafayette Utilities System Louis ``Doc''   Units 1, 2, and 3...........  Lafayette.
 Bonin Electric Generating Station.
Terrebonne Parish Consolidated Government  Units 15 and 16.............  Terrebonne.
 Houma Generating Station.
City of Natchitoches Utility Department..  3 boilers...................  Natchitoches.
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* We are not acting on BART determinations for Entergy Nelson in this action. We will address BART for Entergy
  Nelson in a future rulemaking.

B. Evaluation of Which Sources Are Subject to BART

    Because Louisiana's 2008 Regional Haze SIP relied on CAIR as better
than BART for EGUs, the submittal did not include a determination of
which BART-eligible EGUs were subject to BART. On May 19, 2015, we sent
CAA Section 114 letters to several BART-eligible sources in Louisiana.
In those letters, we noted our understanding that the sources were
actively working with LDEQ to develop a SIP. However, in order to be in
a position to develop a FIP should that be necessary, we requested
information regarding the BART-eligible sources. The Section 114
letters required sources to conduct modeling to determine if the
sources were subject to BART, and included a modeling protocol. The
letters also requested that a BART analysis be performed in accordance
with the BART Guidelines for those sources determined to be subject to
BART. We worked closely with those BART-eligible facilities and with
LDEQ to this end, and all the information we received from the
facilities was also sent to LDEQ. As a result, the LDEQ submitted a
revised SIP submittal on February 10, 2017, that evaluates BART-
eligible EGUs in the State and provides a BART determination for each
such source for all visibility impairing pollutants except
NOX. This proposal addresses the entire 2017 Louisiana
Regional Haze SIP, but for the portion concerning one BART-eligible EGU
facility, specifically the Entergy Nelson facility. We will propose
action on the Entergy Nelson portion of the SIP at a later date. We
note that Louisiana unintentionally omitted discussion of two BART-
eligible facilities in its 2017 Louisiana Regional Haze SIP: Terrebonne
Parish Consolidated Government Houma Generating Station and Louisiana
Energy and Power Authority Plaquemine Steam Plant. We will address
these two sources in the model plant analysis section below.

C. Sources That Are No Longer in Operation

    Several sources that were identified as BART-eligible have since
retired from operation, rendering them no longer subject to the
requirements of the Regional Haze Rule. For the units identified in the
Table 2, the LDEQ provided documentation supporting permit rescissions
to make these retirements permanent and enforceable.\17\
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    \17\ See Appendix E of the 2017 Louisiana Regional Haze SIP for
supporting documentation and the TSD for this action for additional
information.

                                            Table 2--Retired Sources
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              Facility name                            Units                              Parish
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Louisiana Energy and Power Authority,      Units 1, 2, 3, and 4 boilers  St. Mary/St. Martin.
 Morgan City Steam Plant.
City of Ruston, Ruston Electric            Boilers 1, 2, and 3.........  Lincoln.
 Generating Plant.
City of Natchitoches Utility Department..  3 boilers...................  Natchitoches.
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    In addition, Entergy Michoud Units 2 and 3 were identified as BART-
eligible, but are no longer in operation. By letter dated August 10,
2016, Entergy System Operating Committee elected to permanently retire
Michoud Units 2 and 3, effective June 1, 2016. This action was
described in detail through a permit application to the state. As of
the time of this proposal, LDEQ has not yet finalized that permit. The
2017 Louisiana Regional Haze SIP includes the Air Permit Briefing Sheet
that confirms Entergy's request to remove Units 2 and 3 from the
permit.\18\ We propose to approve the SIP based on the draft permit,
and note that we expect the proposed permit removing Units 2 and 3 to
be final before we take final action to approve this portion of the
2017 Louisiana Regional Haze SIP. Alternatively, LDEQ could submit
another enforceable document to ensure that Units 2 and 3 cannot
restart without a BART analysis and emission limits, or demonstrate the
units have been deconstructed to the point that they cannot restart
without obtaining a new NSR permit, making them not operational during
the timeframe for BART eligibility.
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    \18\ See Appendix D of the 2017 Louisiana Regional Haze SIP.

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D. Sources That Screened Out of BART

    Once a list of BART-eligible sources still in operation within a
state has been compiled, the state must determine whether to make BART
determinations for all of them or to consider exempting some of them
from BART because they are not reasonably anticipated to cause or
contribute to any visibility impairment in a Class I area. The BART
Guidelines present several options that rely on modeling analyses and/
or emissions analyses to determine if a source is not reasonably
anticipated to cause or contribute to visibility impairment in a Class
I area. A source that is not reasonably anticipated to cause or
contribute to any visibility impairment in a Class I area is not
``subject to BART,'' and for such sources, a state need not apply the
five statutory factors to make a BART determination.\19\ Those sources
are determined to be not subject to BART. Sources that are reasonably
anticipated to cause or contribute to any visibility impairment in a
Class I area are subject to BART.\20\ For each source subject to BART,
40 CFR 51.308(e)(1)(ii)(A) requires that the LDEQ identify the level of
control representing BART after considering the factors set out in CAA
section 169A(g)(2). To determine which sources are anticipated to
contribute to visibility impairment, the BART Guidelines state ``you
can use CALPUFF or other appropriate model to estimate the visibility
impacts from a single source at a Class I area.'' \21\
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    \19\ See 40 CFR part 51, Appendix Y, III, How to Identify
Sources ``Subject to BART''.
    \20\ Id.
    \21\ See 40 CFR part 51, Appendix Y, III, How to Identify
Sources ``Subject to BART''.
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1. Visibility Impairment Threshold
    The preamble to the BART Guidelines advises that, ``for purposes of
determining which sources are subject to BART, States should consider a
1.0 deciview \22\ change or more from an individual source to `cause'
visibility impairment, and a change of 0.5 deciviews to `contribute' to
impairment.'' \23\ It further advises that ``States should have
discretion to set an appropriate threshold depending on the facts of
the situation,'' and describes situations in which states may wish to
exercise that discretion, mainly in situations in which a number of
sources in an area are all contributing fairly equally to the
visibility impairment of a Class I area. In Louisiana's 2008 Regional
Haze SIP submittal, the LDEQ used a contribution threshold of 0.5 dv
for determining which sources are subject to BART, and we approved this
threshold in our previous action.\24\ The 2017 SIP revision includes a
full five factor BART determination for each of the State's BART-
eligible EGUs whose visibility impacts exceed the 0.5 dv threshold.
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    \22\ As we note in the Regional Haze Rule (64 FR 35725, July 1,
1999), the ``deciview'' or ``dv'' is an atmospheric haze index that
expresses changes in visibility. 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.
    \23\ 70 FR 39104, 39120 (July 6, 2005), [40 CFR part 51,
Appendix Y].
    \24\ See, 77 FR 11839, 11849 (February 28, 2012).
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2. Model Plant Analysis
    As part of our development of the BART Guidelines, we developed
analyses of model plants with representative plume and stack
characteristics for both EGU and non-EGU sources using the CALPUFF
model.\25\ As we discuss in the BART Guidelines,\26\ based on those
analyses, we believe that sources that emit less than 1,000 tons per
year of NOX and SO2 and that are located more
than 100 km from any Class I area can be exempted from the BART
determination. The BART Guidelines note that the model plant concept
can be extended using additional modeling analyses to ratios of
emission levels and distances other than 1,000 tons/100 km. The BART
Guidelines explain that: ``you may find based on representative plant
analyses that certain types of sources are not reasonably anticipated
to cause or contribute to visibility impairment. To do this, you may
conduct your own modeling to establish emission levels and distances
from Class I areas on which you can rely to exempt sources with those
characteristics.'' \27\ Modeling analyses of representative plants are
used to reflect groupings of specific sources with important common
characteristics.
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    \25\ CALPUFF Analysis in Support of the June 2005 Changes to the
Regional Haze Rule, U.S. Environmental Protection Agency, June 15,
2005, Docket No. OAR-2002-0076.
    \26\ 70 FR 39119 (July 6, 2005).
    \27\ 70 FR 39163 (July 6, 2005).
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    As we mention above, we note that Louisiana unintentionally omitted
discussion of two BART-eligible facilities in its 2017 Louisiana
Regional Haze SIP: Terrebonne Parish Consolidated Government Houma
Generating Station (Houma) and Louisiana Energy and Power Authority
Plaquemine Steam Plant (Plaquemine). However, Louisiana's 2008 Regional
Haze SIP submittal identified these two sources as BART-eligible, and
we approved the inclusion of these two sources on that list in
2012.\28\ The LDEQ has indicated that it inadvertently failed to
address whether these two sources are subject to BART in the 2017
Regional Haze SIP. These two sources were included in its 2008 Regional
Haze SIP, but Louisiana relied on CAIR better than BART coverage for
these sources when they adopted their 2008 SIP. Therefore, we have
evaluated these two sources based on available information to determine
whether they are subject to BART. We are not relying on the 1000 tpy/
100 km model plant approach but are instead relying on existing
modeling included in the 2008 Louisiana Regional Haze SIP as being a
representative plant analysis for the purpose of establishing emission
levels and distances to exempt BART-eligible sources. Specifically, the
2008 Louisiana Regional Haze SIP included review of CALPUFF modeling of
a source owner, Valero, which demonstrated that Valero's BART-eligible
sources do not cause or contribute to visibility impairment at the
nearby Class I area, Breton National Wildlife Refuge (Breton). The
Valero plant is representative (similar stack height and parameters) of
the Houma and Plaquemine sources and can therefore be relied on in a
model plant analysis to demonstrate that, based on baseline emissions
and distance to the Class I area, the Houma and Plaquemine sources are
not anticipated to cause or contribute to visibility impairment at
Breton and are therefore not subject to BART.\29\ We analyzed the ratio
of visibility impairing pollutants, denoted as `Q' (NOX,
SO2, and PM-10 in tons/year) \30\ to the distance, denoted
as `D' (distance of source to Breton in km). For example, if two
sources were similar but one has a lower Q/D value, the lower ratio
value (either due to lower emissions and/or greater distance) would be
expected to have smaller visibility impacts at Breton. The Q/D ratio
for Houma and Plaquemine are significantly lower compared to Valero's
ratio (See Table 3). The Q/D ratios of Houma are approximately 20% of
Valero's, and Plaquemine's ratio is less than 10% of Valero's Q/D
ratio, and modeled impacts of the Valero source were less than the 0.5
dv threshold.

Therefore, the data demonstrates that visibility impacts from the BART-
eligible units at Houma and Plaquemine are reasonably anticipated to be
less than the modeled impacts from Valero and less than the 0.5 dv
threshold to screen out. See the CALPUFF Modeling TSD for additional
discussion of the model plant analysis.
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    \28\ See Appendix E of the 2008 Louisiana RH SIP contained in
the docket for the rulemaking at: 77 FR 11839, 11848.
    \29\ See 40 CFR part 51 Appendix Y.
    \30\ To calculate Q, the maximum 24-hr emissions for
NOX, SO2 and PM from the 2000-2004 baseline
were identified for each BART-eligible unit at a source (See Table
9.3 of the 2008 Louisiana RH SIP). Emissions are not paired in time
(i.e. max 24- hour NOX emissions value would not usually
be on the same day as max 24-hour SO2 emissions). The sum
of these daily max NOX, PM and SO2 emissions
were summed and then multiplied by 365 days.
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    We also note that on December 11, 2015, the Lafayette Utilities
System Louis ``Doc'' Bonin Generating Station advised our Clean Air
Markets Division that: Unit 1 last operated on June 22, 2011, and was
put into cold storage on June 1, 2013; Unit 2 last operated on July 5,
2013, and was put into cold storage on June 29, 2014; and Unit 3 last
operated on August 27, 2013, and was put into cold storage on June 24,
2014. The Midcontinent Independent System Operator (MISO) is currently
conducting a study to predict the future use of these unit(s) for
peaking purposes. If it is determined that these units are no longer
necessary to facilitate electrical power generation, they will be
retired.\31\ However, at this time Lafayette Utilities System has not
yet submitted a request to rescind the permit for the Louis ``Doc''
Bonin Electric Generating Station. Because placing the units in cold
storage is not a permanent and enforceable closure under the Regional
Haze requirements, we included Louis ``Doc'' Bonin in our model plant
analysis. The Q/D ratio for Louis ``Doc'' Bonin is significantly lower
compared to Valero's Q/D ratio (See Table 3). The ratio is less than
40% of Valero's ratio and modeled impacts of the Valero source were
less than the 0.5 dv threshold, which demonstrates that visibility
impairment from the BART-eligible units at Louis ``Doc'' Bonin are
reasonably anticipated to be less than the modeled impacts from Valero
and below the 0.5 dv threshold to screen out. The model plant analysis
demonstrates that, based on baseline emissions, the source is not
anticipated to cause or contribute to visibility impairment of any
Class I area, and is therefore not subject to BART. See the CALPUFF
Modeling TSD for additional discussion of the model plant analysis.
Because the modeling results demonstrate that Louis ``Doc'' Bonin is
not subject to BART, we propose to approve this portion of the 2017
Louisiana Regional Haze SIP.
---------------------------------------------------------------------------

    \31\ See Appendix E of the 2017 Louisiana Regional Haze SIP.

                                                             Table 3--Model Plant Q/D Ratios
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Facility                                 Max
                              Facility                               NOX (TPY)  SOX (TPY)   PM (TPY)   emissions   Distance to   Q/D (TPY/    percentile
                                                                                (TPY)     Breton (km)      km)        Delta DV
--------------------------------------------------------------------------------------------------------------------------------------------------------
Terrebonne Parish Consolidated Government Houma Generating Station.      909.8       3.65        7.3       930.75          165         5.64
Louisiana Energy and Power Authority Plaquemine Steam Plant........     492.75          0          0       492.75        227.1         2.17
Lafayette Utilities System Louis ``Doc'' Bonin Electric Generating        2993        7.3      109.5       3109.8        298.9        10.04
 Station...........................................................
Valero.............................................................       1876       1091      401.5       3368.5        139.3        24.18        0.484
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on the results of this analysis, we propose that the BART-
eligible sources identified in Table 4 are not reasonably anticipated
to cause or contribute to the visibility impairment at a Class I area
and are not subject to BART.

                            Table 4--Sources Screened Out Using Model Plant Analysis
----------------------------------------------------------------------------------------------------------------
              Facility Name                            Units                              Parish
----------------------------------------------------------------------------------------------------------------
Louisiana Energy and Power Authority       Boilers 1 and 2.............  Iberville.
 Plaquemine Steam Plant.
Lafayette Utilities System Louis ``Doc''   Units 1, 2, and 3...........  Lafayette.
 Bonin Electric Generating Station.
Terrebonne Parish Consolidated Government  Units 15 and 16.............  Terrebonne.
 Houma Generating Station.
----------------------------------------------------------------------------------------------------------------

3. CALPUFF Modeling To Screen Out Sources
    Some sources were modeled directly with CALPUFF to determine
whether the BART-eligible source causes or contributes to visibility
impairment in nearby Class I areas. The maximum 98th percentile impact
from the modeled years (calculated based on annual average natural
background conditions) was compared with the 0.5 dv screening threshold
following the modeling protocol described in the CALPUFF Modeling TSD.
The BART Guidelines recommend that states use the 24-hour average
actual emission rate from the highest emitting day of the
meteorological period modeled, unless this rate reflects periods of
start-up, shutdown, or malfunction. The maximum 24-hour emission rate
(lb/hr) for NOX and SO2 from the initial baseline
period (with the noted difference for Big Cajun II discussed below) for
each source was identified through a review of the daily emission data
for each BART-eligible unit from EPA's Air Markets Program Data.\32\
See the CALPUFF Modeling TSD for additional discussion and model
results for this portion of the screening analysis.
---------------------------------------------------------------------------

    \32\ http://ampd.epa.gov/ampd/.
---------------------------------------------------------------------------

    As previously discussed, LDEQ submitted its initial Regional Haze
SIP in 2008 and relied on CAIR as a substitute for BART for
SO2 and NOX for all of its BART-eligible EGUs.
Due to reliance on CAIR, that SIP submittal did not include a
determination of which BART-eligible EGUs were subject to BART. EPA's
limited disapproval of Louisiana's Regional Haze SIP due to the State's
reliance on CAIR revived Louisiana's obligation to provide a SIP to
fully address EGU BART.\33\ While Louisiana's 2017 Regional Haze SIP
revision relies on CSAPR for EGU BART for NOX, it does not
provide an alternative to source-by-source EGU BART for SO2
and PM. Therefore, Louisiana's 2017 Regional Haze SIP revision included
modeling of the impacts of the 24-hour maximum emission rate during the
2000-2004

baseline period (with the noted exception of Big Cajun II discussed
below) of all visibility-impairing pollutants from all BART-eligible
units at the facility. BART-eligible sources with visibility impacts
above the 0.5 dv threshold are subject to BART.
---------------------------------------------------------------------------

    \33\ 77 FR 33642 (June 7, 2012).
---------------------------------------------------------------------------

    The Big Cajun II Power Plant is a coal-fired power station owned
and operated by Louisiana Generating, LLC, (a subsidiary of NRG
Energy). In our prior action on the 2008 Regional Haze SIP submittal,
we approved Louisiana's determination that Big Cajun II has two BART-
eligible units, Unit 1 and Unit 2.\34\ Unit 1 is a coal-fired unit, and
Unit 2 was formerly a coal-fired unit but is now a gas-fired unit. The
LDEQ's screening modeling for Big Cajun II accounted for current
operating conditions at the facility. The modeling analysis was
conducted using the current enforceable short term emission limits from
the facility that reflect controls installed after the 2008 Regional
Haze SIP submittal.
---------------------------------------------------------------------------

    \34\ See TSD Table 6 in the Rulemaking Docket numbered EPA-R06-
OAR-2008-0510.
---------------------------------------------------------------------------

    On March 6, 2013, Louisiana Generating entered a consent decree
(CD) with EPA, the LDEQ, and others to resolve a complaint filed
against Louisiana Generating for several violations of the CAA at Big
Cajun II. U.S. et al v. Louisiana Generating, LLC, Civil Action No. 09-
100-JJB-RLB (M.D. La.). Among other things, the CD requires Louisiana
Generating to refuel Big Cajun II Unit 2 to natural gas, and install
and continuously operate dry sorbent injection (DSI) at Big Cajun II
Unit 1 while maintaining a 30-day rolling average SO2
emission rate of no greater than 0.380 lb/MMBtu by no later than April
15, 2015.\35\ Prior to the submittal of the 2017 Regional Haze SIP, the
LDEQ and Louisiana Generating entered into an Agreed Order on Consent
(AOC) that made these existing control requirements and maximum daily
emission limits permanent and enforceable for BART. The AOC is included
in Louisiana's 2017 SIP revision. Thus, if the EPA finalizes its
proposed approval of this portion of the SIP submittal, the control
requirements and emission limits will become permanent and federally
enforceable for purposes of regional haze. As these controls were not
installed to meet BART requirements, and existing enforceable emission
limits for Units 1 and 2 prevent the source from emitting at levels
seen during the 2000-2004 baseline, LDEQ's screening modeling in the
2017 Regional Haze SIP submittal utilizes the current daily emission
limits for these units in the AOC as representative of the anticipated
24-hr maximum emissions for screening modeling purposes. LDEQ's
modeling demonstrates that, based on these existing controls and
enforceable emission limits, Big Cajun II contributes less than 0.5 dv
at all impacted Class I areas, and therefore the facility is not
subject to BART.
---------------------------------------------------------------------------

    \35\ CD paragraph 62 in the docket for this rulemaking.
---------------------------------------------------------------------------

    It should be noted that in addition to requiring DSI, the
applicable enforcement CD requires Louisiana Generating to retire,
refuel, repower, or retrofit Big Cajun II Unit 1 by no later than April
1, 2025. Louisiana Generating must notify us of which option it will
select to comply with this condition no later than December 31, 2022,
and any option taken would produce significantly fewer emissions.\36\
---------------------------------------------------------------------------

    \36\ CD paragraph 63 in the docket for this rulemaking.
---------------------------------------------------------------------------

    With the use of CALPUFF modeling results, Louisiana concluded, and
we are proposing to agree, that the facilities listed in Table 5 have
visibility impacts of less than 0.5 dv,\37\ and therefore, are not
subject to BART:
---------------------------------------------------------------------------

    \37\ In our previous action on Louisiana Regional Haze, we
approved Louisiana's selection of 0.5 dv as the threshold for
screening out BART-eligible sources. See 77 FR 11839, 11848.

                           Table 5--Sources With Visibility Impact of Less Than 0.5 dv
----------------------------------------------------------------------------------------------------------------
              Facility name                            Units                              Parish
----------------------------------------------------------------------------------------------------------------
Cleco Teche..............................  Unit 3......................  St. Mary.
Entergy Sterlington......................  Unit 7......................  Ouachita.
Louisiana Generating (NRG) Big Cajun I...  Units 1 and 2...............  Point Coupee.
Louisiana Generating (NRG) Big Cajun II..  Units 1 and 2...............  Pointe Coupee.
----------------------------------------------------------------------------------------------------------------

E. Subject to BART Sources

    With the use of CALPUFF modeling results as discussed above,
Louisiana concluded, and we are proposing to agree, that the facilities
listed in Table 6 have visibility impacts greater than 0.5 dv. These
facilities are therefore subject to BART and must undergo a five-factor
analysis. See the CALPUFF Modeling TSD for our review of CALPUFF
modeling in the 2017 Louisiana Regional Haze SIP.

                           Table 6--Subject to BART Sources Addressed in This Proposal
----------------------------------------------------------------------------------------------------------------
              Facility name                            Units                              Parish
----------------------------------------------------------------------------------------------------------------
Cleco Rodemacher/Brame...................  Nesbitt I (Unit 1),           Rapides.
                                            Rodemacher II (Unit 2).
Entergy Waterford........................  Units 1, 2, and auxiliary     St. Charles.
                                            boiler.
Entergy Willow Glen......................  Units 2, 3, 4, 5, and         Iberville.
                                            auxiliary boiler.
Entergy Ninemile Point...................  Units 4 and 5...............  Jefferson.
Entergy Little Gypsy.....................  Units 2, 3, and auxiliary     St. Charles.
                                            boiler.
----------------------------------------------------------------------------------------------------------------

    We note that in addition to the CALPUFF modeling included in the
2017 Louisiana Regional Haze SIP submittal, the results of CAMx
modeling performed by Trinity consultants was included in the submittal
as additional screening analyses \38\ that purport to demonstrate that
the baseline visibility impacts from Cleco Brame and a

number of the Entergy sources \39\ are significantly less than the 0.5
dv threshold established by Louisiana. However, this modeling was not
conducted in accordance with the BART Guidelines and a previous
modeling protocol developed for the use of CAMx modeling for BART
screening (EPA, Texas and FLM representatives
approved),40 41 and does not properly assess the maximum
baseline impacts. Therefore, we agree with LDEQ's decision to not rely
on this CAMx modeling, but rather rely on the CALPUFF modeling for BART
determinations.\42\ We provide a detailed discussion of our review of
this CAMx modeling in the CAMx Modeling TSD. We also note that for the
largest emission sources, those with coal-fired units, we performed our
own CAMx modeling following the BART Guidelines and consistent with
previously agreed techniques and metrics of the Texas CAMx BART
screening protocol to provide additional information on visibility
impacts and impairment and address possible concerns with utilizing
CALPUFF to assess visibility impacts at Class I areas located farther
from the emission sources. See the CAMx Modeling TSD for additional
information on EPA's CAMx modeling protocol, inputs, and model results.
---------------------------------------------------------------------------

    \38\ See October 10, 2016 Letter from Cleco Corporation to
Vivian Aucoin and Vennetta Hayes, LDEQ, RE: Cleco Corporation
Louisiana BART CAMx Modeling, included in Appendix B of the 2017
Louisiana Regional Haze SIP submittal; CAMx Modeling Report,
prepared for Entergy Services by Trinity Consultants, Inc. and All 4
Inc, October 14, 2016, included in Appendix D of the 2017 Louisiana
Regional Haze SIP submittal.
    \39\ Entergy's CAMx modeling included model results for Michoud,
Little Gypsy, R.S. Nelson, Ninemile Point, Willow Glen, and
Waterford.
    \40\ Texas had over 120 BART-eligible facilities located at a
wide range of distances to the nearest class I areas in their
original Regional Haze SIP. Due to the distances between sources and
Class I areas and the number of sources, Texas worked with EPA and
FLM representatives to develop a modeling protocol to conduct BART
screening of sources using CAMx photochemical modeling. Texas was
the only state that screened sources using CAMx and had a protocol
developed for how the modeling was to be performed and what metrics
had to be evaluated for determining if a source screened out. See
Guidance for the Application of the CAMx Hybrid Photochemical Grid
Model to Assess Visibility Impacts of Texas BART Sources at Class I
Areas, ENVIRON International, December 13, 2007, available in the
docket for this action.
    \41\ EPA, the Texas Commission on Environmental Quality (TCEQ),
and FLM representatives verbally approved the approach in 2006 and
in email exchange with TCEQ representatives in February 2007 (see
email from Erik Snyder (EPA) to Greg Nudd of TCEQ Feb. 13, 2007 and
response email from Greg Nudd to Erik Snyder Feb. 15, 2007,
available in the docket for this action).
    \42\ See Response to Comments in Appendix A of the 2017
Louisiana Regional Haze SIP submittal.
---------------------------------------------------------------------------

1. Reliance on CSAPR To Satisfy NOX BART
    Louisiana's 2017 Regional Haze SIP submittal relies on CSAPR better
than BART for NOX for EGUs. We propose to find that the
NOX BART requirements for EGUs in Louisiana will be
satisfied by our determination, proposed for separate finalization,
that Louisiana's participation in CSAPR's ozone-season NOX
program is a permissible alternative to source-specific NOX
BART. We cannot finalize this portion of the proposed SIP approval
unless and until we finalize the proposed finding that CSAPR continues
to be better than BART \43\ because finalization of that proposal
provides the basis for Louisiana to rely on CSAPR participation as an
alternative to source-specific EGU BART for NOX.
---------------------------------------------------------------------------

    \43\ 81 FR 78954.
---------------------------------------------------------------------------

2. Sources That Deferred a Five-Factor Analysis Due to a Change in
Operation
    Entergy operates five BART-eligible units at the Willow Glen
Electric Generating Plant (Willow Glen) in Iberville Parish, Louisiana,
all of which burn natural gas. Unit 2 is an EGU boiler with a maximum
heat input capacity of 2,188 MMBtu/hr. Unit 3 is an EGU boiler with a
maximum heat input capacity of 5,900 MMBtu/hr. Unit 4 is an EGU boiler
with a maximum heat input capacity of 5,400 MMBtu/hr. Unit 5 is an EGU
boiler with a maximum heat input capacity of 5,544 MMBtu/hr. Unit 3
also has an auxiliary boiler with a maximum heat input capacity of 206
MMBtu/hr, which is itself BART-eligible. All of these units are also
permitted to burn fuel oil, but none has done so in several years.
Entergy has no operational plans to burn oil at these units in the
future. Entergy's analysis, included in the 2017 Louisiana Regional
Haze SIP Appendix D, addresses BART for the natural-gas-firing scenario
and does not consider emissions from fuel-oil firing. Entergy's
analysis states that if conditions change such that it becomes economic
to burn fuel oil, the facility will submit a five-factor BART analysis
for the fuel-oil firing scenario to Louisiana to be submitted to us as
a SIP revision. Until such a SIP revision is approved, the 2017
Louisiana Regional Haze SIP precludes fuel-oil combustion at the Willow
Glen facility. To make the prohibition on fuel-oil usage at Willow Glen
enforceable, Entergy and LDEQ entered an AOC, included in the SIP that
establishes the following requirement:

    Before fuel oil firing is allowed to take place at Units 2, 3,
4, 5, and the auxiliary boiler at the Facility, a revised BART
determination must be promulgated for SO2 and PM for the
fuel oil firing scenario through a FIP or an action by the LDEQ as a
SIP revision and approved by EPA such that the action will become
federally enforceable.\44\
---------------------------------------------------------------------------

    \44\ See AOC in Appendix D of the 2017 Louisiana Regional Haze
SIP submittal.

    With our final approval of this portion of the SIP submittal, the
conditions in the AOC will become federally enforceable for purposes of
regional haze. We propose to find that this approach is adequate to
address BART.\45\
---------------------------------------------------------------------------

    \45\ Under the AOC, if any of the five units at Willow Glen
decides to burn fuel oil, Entergy will complete a BART analysis for
each pollutant for the fuel oil firing scenario and submit the
analysis to the State. Upon receiving Entergy's submission
indicating that the units intend to switch to fuel oil, the State
will submit a SIP revision with BART determinations for the fuel oil
firing scenario for the units intending to switch to fuel oil. The
sources will not begin to burn fuel oil until we have approved the
submitted SIP revision containing the BART determinations.
---------------------------------------------------------------------------

    With regard to BART requirements for the gas-firing scenario,
SO2 and PM emissions for the gas-only fired units that are
subject to BART are inherently low,\46\ and are so minimal that the
installation of any additional PM or SO2 controls on these
units would likely achieve very small emissions reductions and have
minimal visibility benefits. As there are no appropriate add-on
controls and the status quo reflects the most stringent controls, we
propose to agree with Louisiana that SO2 and PM BART is no
additional controls for the Willow Glen units when burning natural gas.
---------------------------------------------------------------------------

    \46\ AP 42, Fifth Edition, Volume 1, Chapter 1: External
Sources, Section 1.4, Natural Gas Combustion, available here:
https://www3.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf.
---------------------------------------------------------------------------

3. Louisiana's Five-Factor Analyses for SO2 and PM BART
    In determining BART, the state must consider the five statutory
factors in section 169A of the CAA: (1) The costs of compliance; (2)
the energy and non-air 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. See also 40 CFR 51.308(e)(1)(ii)(A). All units
that are subject to BART must undergo a BART analysis. The BART
Guidelines break the analysis down into five steps: \47\
---------------------------------------------------------------------------

    \47\ 70 FR 39103, 39164 (July 6, 2005) [40 CFR 51, App. Y].

    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 mentioned previously, we disapproved portions of Louisiana's
2008 Regional Haze SIP due to the state's reliance on CAIR as an
alternative to source-by-source BART for EGUs.\48\ Following our
limited disapproval, LDEQ worked closely with the BART-eligible
facilities and with us to revise its Regional Haze SIP, which resulted
in the submittal of its 2017 Regional Haze SIP. The 2017 SIP submittal
includes, among other things, a five-factor BART analysis for each
subject to BART source for PM and SO2. Louisiana's 2017
Regional Haze SIP relies on CSAPR participation as an alternative to
source-specific EGU BART for NOX. In evaluating the State's
2017 SIP revision, we reviewed each BART analysis for SO2
and PM for each subject to BART source and other relevant information
provided in the 2017 Regional Haze SIP submittal.
---------------------------------------------------------------------------

    \48\ 77 FR 33642.
---------------------------------------------------------------------------

a. Cleco Brame Energy Center
    The Cleco Brame Energy Center includes two units that are subject
to BART. Nesbitt 1 (Brame Unit 1) is a 440-megawatt (MW) EGU boiler
that burns natural gas and is not equipped with any air pollution
controls. Rodemacher 2 (Brame Unit 2) is a 523 MW wall-fired EGU boiler
that burns Powder River Basin (PRB) coal. Cleco submitted a BART
screening analysis to us and LDEQ on August 31, 2015, and a BART five-
factor analysis dated October 31, 2015, revised April 14, 2016 and
April 18, 2016 in response to an information request.\49\ These
analyses were adopted and incorporated into Louisiana's 2017 Regional
Haze SIP (Appendix B).
---------------------------------------------------------------------------

    \49\ Wren Stenger, Section 114(a) Information Request letter to
Darren Olagues (Cleco), May 19, 2015.
---------------------------------------------------------------------------

Nesbitt 1
    Nesbitt 1 is currently permitted to burn natural gas and oil.
However, this unit has not burned oil in the recent past. LDEQ did not
conduct a five-factor BART analysis for Nesbitt 1, concluding that
``SO2 BART controls are satisfied through the conversion to
natural gas.'' \50\ The preamble to the BART Guidelines states: \51\
---------------------------------------------------------------------------

    \50\ See Cleco BART Analysis in Appendix B of the 2017 Louisiana
Regional Haze SIP.
    \51\ 70 FR 39116.

    Consistent with the CAA and the implementing regulations, States
can adopt a more streamlined approach to making BART determinations
where appropriate. Although BART determinations are based on the
totality of circumstances in a given situation, such as the distance
of the source from a Class I area, the type and amount of pollutant
at issue, and the availability and cost of controls, it is clear
that in some situations, one or more factors will clearly suggest an
outcome. Thus, for example, a State need not undertake an exhaustive
analysis of a source's impact on visibility resulting from
relatively minor emissions of a pollutant where it is clear that
controls would be costly and any improvements in visibility
resulting from reductions in emissions of that pollutant would be
negligible. In a scenario, for example, where a source emits
thousands of tons of SO2 but less than one hundred tons
of NOX, the State could easily conclude that requiring
expensive controls to reduce NOX would not be
---------------------------------------------------------------------------
appropriate.

    SO2 and PM emissions from gas-fired units are inherently
low,\52\ so the installation of any additional PM or SO2
controls on this unit would likely achieve very small emissions
reductions and have minimal visibility benefits.
---------------------------------------------------------------------------

    \52\ AP 42, Fifth Edition, Volume 1, Chapter 1: External
Sources, Section 1.4, Natural Gas Combustion, available here:
https://www3.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf.
---------------------------------------------------------------------------

    Before burning fuel oil at this unit, Cleco has committed to submit
a five-factor BART analysis for the fuel-oil-firing scenario to
Louisiana to be submitted to us as a SIP revision, and fuel oil
combustion will not take place until our final approval of that SIP
revision. To make the prohibition on fuel-oil usage at this unit
enforceable, Cleco and LDEQ entered an AOC that establishes enforceable
limits, consistent with the exclusive use of natural gas, of 3.0 lb/hr
SO2 and 37.3 lb/hr PM10 on 30-day rolling
averages and a limitation on Nesbitt 1 analogous to the limitation for
Willow Glen discussed previously.\53\ This AOC is included in
Louisiana's 2017 SIP revision. With our final approval of this portion
of the 2017 SIP submittal and the AOC, that limitation will become
federally enforceable for purposes of Regional Haze. We propose to find
this approach adequate to meet BART.
---------------------------------------------------------------------------

    \53\ See AOC in Appendix B of the 2017 Louisiana Regional Haze
SIP.
---------------------------------------------------------------------------

Rodemacher 2
    As the 2017 Louisiana Regional Haze SIP indicates,\54\ recent
pollution control upgrades at Rodemacher 2 include:
---------------------------------------------------------------------------

    \54\ See BART Analysis in Appendix B of the 2017 Louisiana
Regional Haze SIP.

     Low-NOX burners (LNB) installed in 2008;
     Low-sulfur coal combustion starting in 2009;
     Selective non-catalytic reduction (SNCR) installed in
2014; and
     DSI, activated carbon injection (ACI), and a fabric
filter baghouse installed in 2015.

    In assessing SO2 BART, Cleco considered the five BART
factors we discuss above. In assessing feasible control technologies
and their effectiveness, Cleco considered an enhancement to the
existing DSI system, dry scrubbing (spray dry absorption, or SDA), and
wet scrubbing (wet flue gas desulfurization, or wet FGD). In
considering enhanced DSI, Cleco relied upon on-site testing it had
conducted to determine the performance potential of an enhanced DSI
system. The testing was conducted to evaluate the effectiveness of the
DSI system to control hydrochloric acid for compliance with the Mercury
and Air Toxics Standards (MATS), but the continuous emissions monitor
system (CEMS) was operating and capturing SO2 emissions data
during the test, which provided the necessary information to determine
the control efficiency of DSI and enhanced DSI for SO2.\55\
As a result of this testing, Cleco determined that the current and
enhanced DSI systems have SO2 removal efficiencies of
approximately 39% and 63%, respectively, with the enhanced DSI system
being capable of meeting a monthly SO2 emission limit of
0.30 lbs/MMBtu. Cleco secured this limit as part of the same AOC
referenced above for the Nesbitt 1. Cleco also assessed SDA and wet FGD
as being capable of meeting emission limits of 0.06 and 0.04 lbs/MMBtu,
respectively.
---------------------------------------------------------------------------

    \55\ See the April 5, 2016 letter to Guy Donaldson from Bill
Matthews in our docket.
---------------------------------------------------------------------------

    In considering the costs of compliance for these controls, Cleco
concluded that the enhanced DSI system would not require any additional
capital expenses, but would require additional operating costs due to
the need for additional sorbent (trona). Cleco didn't specifically
address the energy impacts and non-air quality impacts of enhanced DSI,
but we conclude that any considerations regarding these factors would
be very minimal over the already installed DSI system. Cleco also
assessed the costs associated with installing and operating SDA and wet
FGD, as discussed below. In regards to energy impacts and non-air
quality impacts, Cleco concluded that wet FGD poses certain water and
waste disposal problems over SDA. Cleco concluded that remaining useful
life was not an important factor for any of the control scenarios.
    In assessing visibility impacts, the state's submittal included
CALPUFF modeling evaluating the visibility benefits of DSI, enhanced
DSI, SDA, and wet FGD. We summarize the results of that modeling in
Table 7.
---------------------------------------------------------------------------

    \56\ DSI modeled at 0.41 lb/MMBtu, DSI and fabric filter are
already installed and operational.

               Table 7--Anticipated Visibility Benefit Due to Controls on Cleco Rodemacher Unit 2
                                           [CALPUFF, 98th percentile]
----------------------------------------------------------------------------------------------------------------
                                                         Visibility benefit of controls over baseline (dv)
          Class I area               Baseline    ---------------------------------------------------------------
                                    impact (dv)      DSI \56\      Enhanced DSI         SDA            WFGD
----------------------------------------------------------------------------------------------------------------
Breton..........................           0.724           0.134           0.226           0.436           0.445
Caney Creek.....................           0.734           0.085           0.122           0.311           0.322
----------------------------------------------------------------------------------------------------------------

    Enhanced DSI achieves benefits of approximately 0.092 dv at Breton
and 0.037 dv at Caney Creek Wilderness (Caney Creek) over DSI and
benefits of 0.226 dv at Breton and 0.122 dv at Caney Creek over the
baseline impairment. The visibility benefits of SDA and wet FGD exceed
the benefits from enhanced DSI by approximately 0.2 dv at Caney Creek
and Breton.
    We also performed our own CAMx modeling analysis for Cleco
Rodemacher Unit 2 following the BART Guidelines to evaluate the maximum
baseline visibility impacts and potential benefits from two levels of
controls, DSI at 0.41 lb/MMBtu and wet FGD at 0.04 lb/MMBtu, to
supplement the CALPUFF modeling. As discussed above, Louisiana relied
on CALPUFF modeling to inform BART determinations consistent with the
BART Guidelines. However, the use of CALPUFF is typically used for
distances less than 300-400 km. The Cleco Brame source is located 352
km from Caney Creek and 422 km from Breton. CAMx provides a
scientifically validated platform for assessment of visibility impacts
over a wide range of source-to-receptor distances. CAMx is also more
suited than some other modeling approaches for evaluating the impacts
of SO2, NOX, VOC, and PM emissions as it has a
more robust chemistry mechanism than CALPUFF. Our CAMx Modeling TSD
provides a detailed description of the modeling protocol, model inputs,
and model results, the latter of which is summarized in Table 8.
---------------------------------------------------------------------------

    \57\ DSI modeled at 0.41 lb/MMBtu, DSI and fabric filter are
already installed and operational.
    \58\ DSI modeled at 0.41 lb/MMBtu, DSI and fabric filter are
already installed and operational.

                                   Table 8--Anticipated Visibility Benefit Due to Controls on Cleco Rodemacher Unit 2
                                                                         [CAMX]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Baseline     Visibility benefit of controls  Visibility benefit of controls
                                                             Baseline       impact (dv)     over baseline (dv) maximum    over baseline (dv) average top
                      Class I area                          impact (dv)    (average top               impact                     ten impacted days
                                                             (maximum)     ten impacted  ---------------------------------------------------------------
                                                                               days)         DSI \57\          WFGD          DSI \58\          WFGD
--------------------------------------------------------------------------------------------------------------------------------------------------------
Breton..................................................           0.713           0.315           0.187           0.399           0.117           0.271
Caney Creek.............................................           2.051           1.005           0.119           0.238           0.271           0.459
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The CAMx-modeled visibility benefits of WFGD are 0.212 dv at Breton
and 0.119 dv at Caney Creek over those from DSI for the most impacted
day. Examining the top ten impacted days during the baseline period,
the average benefit on this set of days of WFGD over DSI is 0.154 dv at
Breton and 0.188 dv at Caney Creek. As enhanced DSI would reduce
SO2 emissions from an emission rate of 0.41 lb/MMBtu to 0.3
lb/MMBtu, enhanced DSI would lead to greater visibility benefits than
DSI. Thus, the visibility benefits of WFGD compared to enhanced DSI
would be smaller than those discussed above.
    As explained in our TSD, we identified some uncertainties with
Cleco's BART analysis for Rodemacher 2. These include a lack of
documentation for cost figures, and the fact that the DSI testing that
Cleco relied on was not intended to evaluate DSI for SO2
control efficiency, which caused some uncertainty concerning the
potential control level of DSI and enhanced DSI. However, because DSI
and a fabric filter baghouse are already installed and operational, the
cost-effectiveness of Cleco's enhanced DSI is based only on the cost of
the additional reagent and no additional capital costs are involved.
Consequently, we believe that the uncertainty of Cleco's enhanced DSI
cost-effectiveness figures is low and that Cleco's estimated cost-
effectiveness of $967/ton \59\ is reasonable. Conversely, we believe
that significant uncertainty exists with respect to Cleco's cost-
effectiveness estimates for SDA and wet FGD--$8,589/ton and $5,580/ton,
respectively. Based on our experience reviewing and conducting control
cost analyses for many other facilities, we believe that Cleco's
estimates are likely too high.
---------------------------------------------------------------------------

    \59\ Cleco lists this as an incremental cost-effectiveness
figure for enhanced DSI over the existing DSI system. However, the
enhanced DSI system has no additional capital costs, and when the
already sunk capital costs of the existing DSI system are removed
(which have been carried forward), the $967/ton figure becomes the
average cost-effectiveness value for enhanced DSI.
---------------------------------------------------------------------------

    Nevertheless, even though the actual costs of SDA and wet FGD are
likely lower, enhanced DSI is more cost-effective and the incremental
costs of obtaining the additional 0.1-0.2 dv of visibility improvement
that can be achieved by SDA or wet FGD are likely to be high.
Therefore, we propose to agree with Louisiana's determination that
enhanced DSI is SO2 BART for Rodemacher 2, with a
SO2 emission limit of 0.30 lbs/MMBtu on a 30-day rolling
basis. LDEQ and Cleco entered into an AOC to make this limit
enforceable.
    In assessing PM BART, Cleco notes that Rodemacher 2 is equipped
with an electrostatic precipitator (ESP) and a fabric filter baghouse,
which offer excellent PM control, and concludes that PM BART is no
further control. As discussed earlier, the BART rules allow for a more
streamlined approach to making BART determinations when
appropriate.\60\ The BART Guidelines further state that if a BART
source

already has controls that are among the most stringent available and
the controls are made federally enforceable for BART, the remainder of
the BART analysis is unnecessary.\61\ The existing ESP combined with
the baghouse meets the definition of ``among the most stringent
controls'' for PM at this unit and are made federally enforceable for
BART through the AOC. The AOC allows the unit to meet the emissions
limits by use of the ESP and the baghouse, conversion to natural gas
only, unit retirement, or another means of achieving compliance.
---------------------------------------------------------------------------

    \60\ 70 FR 39116.
    \61\ 40 CFR 51 Appendix Y.IV.D.1.9.
---------------------------------------------------------------------------

    In addition, CALPUFF visibility modeling shows that baseline
impairment due to PM is very small, at 0.01 dv or less at both Breton
and Caney Creek compared to the overall visibility impairment from all
pollutants of approximately 0.6 dv.\62\ Our CAMx modeling estimates
that baseline visibility impairment due to PM emissions from the unit
is less than 1% of the total visibility impairment due to the unit, at
both Caney Creek and Breton.\63\ We propose to find that the visibility
impacts due to PM emissions are so minimal that any additional PM
controls would only result in very minimal visibility benefit that
could not justify the cost of any upgrades and/or operational changes
needed to achieve a more stringent emission limit. We therefore propose
to agree with Louisiana that no additional controls are required to
satisfy PM BART. LDEQ and Cleco entered into an AOC establishing an
enforceable limit on PM10 consistent with current controls
at 545 lb/hr on a 30-day rolling basis.
---------------------------------------------------------------------------

    \62\ See Table 4-3 CLECO Brame Energy Center BART Five-Factor
Analysis, prepared by Trinity Consultants, October 31, 2015.
Available in Appendix B of the 2017 Regional Haze SIP submittal.
    \63\ Calculated as percent of total extinction due to the unit.
See CAMx Modeling TSD for additional information.
---------------------------------------------------------------------------

b. Entergy Little Gypsy
    Entergy operates three BART-eligible units at Little Gypsy
Generating Plant (Little Gypsy). Unit 2 is an EGU boiler with a maximum
heat input capacity of 4,550 MMBtu/hr that is permitted to burn natural
gas as its primary fuel, and No. 2 and No. 4 fuel oil as secondary
fuels. Unit 3 is an EGU boiler with a maximum heat input capacity of
5,578 MMBtu/hr that burns natural gas, but is also permitted to burn
fuel oil. The auxiliary boiler for Unit 3 has a maximum heat input
capacity of 252 MMBtu/hr and is permitted to burn only natural gas.
According to November 9, 2015 updated CALPUFF screening modeling
conducted by Trinity Consultants on behalf of Entergy,\64\ the baseline
visibility impacts of Little Gypsy are greater than 0.5 dv, so the 2017
SIP revision demonstrates that the three units at Little Gypsy are
subject to BART.\65\
---------------------------------------------------------------------------

    \64\ See Appendix D of the 2017 SIP submittal.
    \65\ See CALPUFF Modeling TSD for a summary of model results.
---------------------------------------------------------------------------

    LDEQ and Entergy entered into an AOC limiting fuel oil to ultra-low
sulfur diesel (ULSD) with a sulfur content of 0.0015% for both Units 2
and 3. As the BART Guidelines state, ``if a source commits to a BART
determination that consists of the most stringent controls available,
then there is no need to complete the remaining analyses.'' \66\
Entergy states that during the baseline period, Units 2 and 3 burned
fuel oil \67\ with an average sulfur content of 0.5%. Switching to ULSD
will result in a reduction of SO2 emissions of over 99%. We
propose to find that ULSD is the most stringent control available for
addressing SO2 emissions from fuel oil burning, and we
propose to agree with LDEQ that this satisfies BART for SO2
for Little Gypsy Unit 2.
---------------------------------------------------------------------------

    \66\ See 40 CFR part 51, Appendix Y, IV, D.
    \67\ For this and all units herein assessed for BART, the
primary fuel burned has historically been pipeline quality natural
gas. Please see the TSD for more details.
---------------------------------------------------------------------------

    The 2017 Louisiana Regional Haze SIP narrative does not include a
BART determination for the auxiliary boiler, but the BART analysis in
Appendix D of the SIP submittal does address the auxiliary boiler and
concludes that no additional controls are necessary for BART. The
auxiliary boiler is permitted to only burn natural gas. We note that
SO2 and PM emissions for gas-fired units are inherently low
\68\ and so minimal that the installation of any additional PM or
SO2 controls on such units would likely achieve very low
emissions reductions and minimal visibility benefits. As there are no
appropriate add-on controls and the status quo reflects the most
stringent controls, we propose to agree with LDEQ that SO2
and PM BART is no additional controls for the Little Gypsy auxiliary
boiler. For the same reason, we propose to approve LDEQ's conclusion
that PM BART for Little Gypsy Units 2 and 3 during gas-firing operation
is no additional controls.
---------------------------------------------------------------------------

    \68\ AP 42, Fifth Edition, Volume 1, Chapter 1: External
Sources, Section 1.4, Natural Gas Combustion, available here:
https://www3.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf.
---------------------------------------------------------------------------

    With regards to PM BART for the fuel-oil-firing scenarios at Units
2 and 3, Louisiana evaluated wet ESP, wet scrubber, cyclone, and
switching fuels to 0.0015% S fuel oil (ULSD). In evaluating energy and
non-air quality impacts, the BART analysis identifies energy impacts
associated with energy usage for ESPs and scrubbers. In addition, ESPs
and scrubbers generate wastewater streams and the resulting wastewater
treatment will generate filter cake, requiring land-filling. LDEQ did
not identify any impacts regarding remaining useful life. The costs of
compliance for these add-on control options are very high compared to
their anticipated visibility benefits.\69\ The modeled visibility
benefits of add-on controls are very small and range from 0.0 dv to
0.037 dv for cyclone, wet scrubber, and wet ESP. Therefore, we propose
that the costs of add-on PM controls do not justify the expected
improvement in visibility. Accordingly, we are proposing to agree with
Louisiana that the fuel sulfur content limits contained in the AOC that
were determined to meet SO2 BART also satisfy PM BART.
---------------------------------------------------------------------------

    \69\ See TSD for summary of PM control cost analysis.
---------------------------------------------------------------------------

c. Entergy Ninemile Point
    Entergy operates two BART-eligible units at Ninemile Point Electric
Generating Plant (Ninemile Point). Unit 4 is an EGU boiler with a
maximum heat input capacity of 7,146 MMBtu/hr that burns primarily
natural gas and No. 2 and No. 4 fuel oil. Unit 5 is an EGU boiler with
a maximum heat input capacity of 7,152 MMBtu/hr that burns primarily
natural gas and No. 2 and No. 4 fuel oil. LDEQ's SIP submittal
demonstrates that the two units at Ninemile Point are subject to BART.
LDEQ and Entergy entered into an AOC limiting fuel oil to ULSD with a
sulfur content of 0.0015%. As the BART Guidelines state ``if a source
commits to a BART determination that consists of the most stringent
controls available, then there is no need to complete the remaining
analyses.'' \70\ Entergy states that during the baseline period these
units burned fuel oil with an average sulfur content of 0.3%. Switching
to ULSD will result in a reduction of SO2 emissions by over
99%. We propose to find that ULSD is the most stringent control
available for addressing SO2 emissions and we propose to
agree with LDEQ that this satisfies BART for SO2 for
Ninemile Point Units 4 and 5.
---------------------------------------------------------------------------

    \70\ See 40 CFR part 51, Appendix Y, IV, D.
---------------------------------------------------------------------------

    For PM BART for Units 4 and 5, Louisiana evaluated wet ESP, wet
scrubber, cyclones, and switching fuels to ULSD. In evaluating energy
and non-air quality impacts, the BART analysis identifies energy
impacts associated with energy usage for ESPs and scrubbers. In
addition, ESPs and

scrubbers generate wastewater streams and the resulting wastewater
treatment will generate filter cake, requiring land-filling. LDEQ did
not identify any impacts regarding the remaining useful life. The cost
of compliance for these add-on control options is very high compared to
the anticipated visibility benefits of controls. The modeled visibility
benefits of add-on controls are very small and range from 0 dv to 0.08
dv for cyclone, wet scrubber and wet ESP. The BART analyses in the 2017
Louisiana Regional Haze SIP demonstrate that the cost of retrofitting
the Units 4 and 5 with add-on PM controls would be extremely high
compared to the visibility benefit for any of the units.\71\ We believe
that the cost of add-on PM controls does not justify the minimal
expected improvement in visibility for these units. Accordingly, we are
proposing to agree with LDEQ's determination that the fuel content
limits for oil burning contained in the AOC that were determined to
meet SO2 BART also satisfy PM BART for Units 4 and 5.
---------------------------------------------------------------------------

    \71\ See TSD for summary of PM control cost analysis.
---------------------------------------------------------------------------

d. Entergy Waterford
    Entergy operates three BART-eligible units at the Waterford 1 & 2
\72\ Generating Plant (Waterford) in St. Charles Parish, Louisiana.
Unit 1 is an EGU boiler with a maximum heat input capacity of 4,440
MMBtu/hr that burns primarily natural gas and No. 6 fuel oil as its
secondary fuel. Unit 2 is an EGU boiler with a maximum heat input
capacity of 4,440 MMBtu/hr that burns primarily natural gas and No. 6
fuel oil as its secondary fuel. The auxiliary boiler (77 MMBtu/hr)
burns only natural gas. We propose to approve the determination that
Waterford Units 1 and 2, and the auxiliary boiler are subject to BART.
In assessing SO2 BART for Units 1 and 2, Louisiana
considered the five BART factors.
---------------------------------------------------------------------------

    \72\ Note that the name of this facility is ``Waterford 1 & 2''
and is also has units that are referred to as ``Unit 1'' and ``Unit
2''.
---------------------------------------------------------------------------

    In Step 1, SO2 control technologies of DSI, SDA, wet
scrubbing, and fuel switching were identified as available controls.
For gas-fired units that occasionally burn fuel oil, the BART
Guidelines recommend: ``For oil-fired units, regardless of size, you
should evaluate limiting the sulfur content of the fuel oil burned to 1
percent or less by weight.'' \73\ The Waterford units have only burned
residual fuel oil (No. 6). Entergy states that these units are only
physically capable of burning No. 6 fuel oil when not burning natural
gas and evaluated switching to 0.5% sulfur No. 6 fuel oil, the lowest
sulfur specification No. 6 fuel oil available.
---------------------------------------------------------------------------

    \73\ 70 FR 39103, 39171 (July 6, 2005) [40 CFR 51, App. Y].
---------------------------------------------------------------------------

    In Step 2, Louisiana eliminated all controls as technically
infeasible with the exception of fuel switching. We are aware, however,
of instances, although not at any facility in the U.S., in which FGDs
of various types have been installed or otherwise deemed feasible on a
boiler that burns oil.\74\ Consequently, we have supplemented
Louisiana's analysis with our own. We propose from our analysis, that
even if the LDEQ included analyses of these other control options, the
State's BART conclusion for Waterford would still be reasonable.\75\
---------------------------------------------------------------------------

    \74\ Crespi, M. ``Design of the FLOWPAC WFGD System for the
Amager Power Plant.'' Power-Gen FGD Operating Experience, November
29, 2006, Orlando, FL; Babcock and Wilcox. ``Wet Flue Gas
Desulfurization (FGD) Systems Advanced Multi-Pollutant Control
Technology.'' See Page 4: ``We have also provided systems for heavy
oil and Orimulsion fuels.'' DePriest, W; Gaikwad, R. ``Economics of
Lime and Limestone for Control of Sulfur Dioxide.'' See page 7: ``A
CFB unit, in Austria, is on a 275 MW size oil-fired boiler burning
1.0-2.0% sulfur oil.''
    \75\ See the TSD for our analysis of these other control
options. We believe that the installation of any of these other add-
on control options, such as a scrubber, on any of these gas-fired
units that occasionally burn oil results in very high cost-
effectiveness values.
---------------------------------------------------------------------------

    In addition, Louisiana evaluated switching from a 1% sulfur fuel
oil, which is approximately equal to the maximum sulfur content of the
fuel oil these units have burned, to a 0.5% sulfur fuel oil for Units 1
and 2. In addition to the Entergy BART report which Louisiana relied
upon, we have included our own fuel oil cost assessment in the TSD.
    For Step 3, the technically feasible controls are ranked by control
effectiveness. The control effectiveness of switching from a higher
sulfur fuel oil to a lower sulfur fuel oil depends on the reduction in
sulfur emissions. Entergy states that these units are only physically
capable of burning No. 6 fuel oil when not burning natural gas and
evaluated switching to 0.5% sulfur No. 6 fuel oil, the lowest sulfur
specification No. 6 fuel oil available. We believe it is likely the
units could be modified to burn distillate fuel oils, with even lower
sulfur content, at low cost. We welcome the facility owner, Entergy, to
provide a cost estimate for the modification to burn distillate fuel
oils should it have concerns with this assumption.
    Because we believe it likely that the facility could be modified to
burn distillate fuels at low cost, in addition to our consideration of
0.5% No. 6 fuel oil, we also considered No. 2 fuel oils with 0.3%
sulfur and ultra-low sulfur diesel, which has a sulfur content of
0.0015%.
    In evaluating energy and non-air quality impacts, the BART analysis
in the 2017 SIP submittal states that there are no such impacts
associated with fuel switching. It also states that remaining useful
life does not impact the BART analysis. We believe Louisiana's
assessment of the impacts from fuel switching are reasonable.
    Aside from our conclusion that modifications necessary to burn
distillate fuel oil are relatively minor, the cost-effectiveness of
fuel oil switching depends only on the cost of the lower sulfur fuel
oil relative to the baseline fuel oil. Information from the Energy
Information Agency (EIA) indicates that fuel oil of varying sulfur
contents is widely available across the U.S. EIA reports the prices for
various refinery petroleum products on a monthly and annual basis. See
the TSD for additional information on fuel oil prices utilized in our
analysis. In Table 9, we present the results of our calculations: \76\
---------------------------------------------------------------------------

    \76\ See the file, ``LA BART Fuel Oil Cost Analysis.xlsx'' for
the calculations and supporting data for these figures.

              Table 9--Control Cost Analysis for Fuel Oil Switching From Residual Fuel Oil Baseline
----------------------------------------------------------------------------------------------------------------
                                        Baseline: Residual Fuel Oil <=1%
-----------------------------------------------------------------------------------------------------------------
                                                                                Tons reduced        Cost
                                                                  Cost for 1,000     per 1,000     effectiveness
                                                                  barrels ($/yr)      barrels         ($/ton)
----------------------------------------------------------------------------------------------------------------
Business as usual (Residual fuel oil @1% S and $0.971/gal)......         $40,782
Moderate control (No. 2 fuel oil @0.3% S and $1.565/gal)........          65,730            2.40         $10,385
High control (ULSD @0.0015% S and $1.667/gal)...................          70,014            3.29           8,878
----------------------------------------------------------------------------------------------------------------

    In assessing the visibility benefits of fuel switching, Louisiana
submitted CALPUFF modeling for 1% sulfur and 0.5% sulfur fuel oil. We
performed additional CALPUFF modeling to correct for errors in the
modeling and to evaluate the visibility benefits of additional fuel
types. See the CALPUFF Modeling TSD for additional information on
modeling inputs and results. The visibility benefits from fuel
switching are summarized in Table 10.

                          Table 10--Visibility Benefits of Fuel Switching at Waterford
                                           [CALPUFF, 98th percentile]
----------------------------------------------------------------------------------------------------------------
                                                                    Visibility      Visibility      Visibility
                                  Class I area       Baseline      benefit (dv)    benefit (dv)    benefit (dv)
                                                    impact (dv)      of 0.5% S       of 0.3% S     of 0.0015% S
----------------------------------------------------------------------------------------------------------------
Unit 1........................  Breton..........           2.704           0.883           1.348           1.744
Unit 2........................  Breton..........           2.378           0.798           1.207           1.601
----------------------------------------------------------------------------------------------------------------

    The cost-effectiveness of switching to a lower sulfur fuel oil is
less attractive (higher $/ton) than other controls we have typically
required under BART. While the visibility benefits of switching fuel
types are significant, the cost-effectiveness in terms of $/ton is in
excess of $8,000/ton for the most stringent control option. We also
note that the facility primarily operates by burning natural gas and
the visibility benefits presented in Table 10 represent benefits only
for those periods when fuel oil is burned and would not occur during
natural gas operation. As discussed above, over the 2011-2015 period,
the highest annual emissions for SO2 reported for a unit at
the facility is only 69 tons/year. Considering this, we propose to
agree with the LDEQ's determination that no additional controls or fuel
switching are necessary to satisfy BART. The LDEQ and Entergy have
entered into an AOC limiting fuel oil sulfur content to 1% or less.
This enforceable limit is consistent with past practice, the baseline
level utilized in the BART analysis, and the minimum recommendation in
the BART Guidelines. We encourage Louisiana and Entergy to reconsider
switching to a lower sulfur fuel when assessing controls under
reasonable progress for future planning periods.
    For PM BART for Units 1 and 2, Louisiana evaluated wet ESP, wet
scrubber, cyclones, and switching fuels to 0.5% S fuel oil. In
evaluating energy and non-air quality impacts, Louisiana identified
energy impacts associated with energy usage for ESPs and scrubbers. In
addition, ESPs and scrubbers generate wastewater streams and the
resulting wastewater treatment will generate filter cake, requiring
land-filling. Louisiana did not identify any impacts regarding
remaining useful life. The costs of compliance for these control
options are very high compared to their anticipated visibility
benefits. Modeled baseline visibility impacts from PM emissions are
very low. Modeled visibility impairment from baseline PM emissions are
less than 5% of the total modeled impact from the source. Entergy's
modeled visibility benefits of add-on controls are very small and range
from 0 dv to 0.06 dv for cyclone, wet scrubber, and wet ESP for each
unit. The BART analyses in the 2017 Louisiana Regional Haze SIP
demonstrate that the cost of retrofitting Units 1 and 2 with add-on PM
controls would be extremely high compared to the visibility benefits
for any of the units.\77\ LDEQ concluded that the costs of add-on PM
controls do not justify the minimal expected improvement in visibility
for these units. LDEQ included an analysis of fuel switching for PM
BART in its SO2 BART analysis, as PM reductions from fuel
switching were also included in the assessment of benefits from fuel
switching. Accordingly, we are proposing to agree with the
determination in the 2017 Louisiana Regional Haze SIP that the fuel
content limits for oil burning contained in the AOC that were
determined to meet SO2 BART also satisfy PM BART.
---------------------------------------------------------------------------

    \77\ See TSD for summary of PM control cost analysis.
---------------------------------------------------------------------------

    The 2017 Louisiana Regional Haze SIP narrative does not include a
BART determination for the auxiliary boiler, but the BART analysis in
Appendix D of the 2017 SIP submittal does address the auxiliary boiler
and concludes that no additional controls are necessary for BART. The
auxiliary boiler only burns natural gas. We note that SO2
and PM emissions for gas-only units are inherently low,\78\ so the
installation of any additional PM or SO2 controls on such
units would likely achieve very low emissions reductions and minimal
visibility benefits. As there are no appropriate add-on controls, and
the status quo reflects the most stringent controls, we propose to
agree with Louisiana that SO2 and PM BART is no additional
controls for the Waterford auxiliary boiler.
---------------------------------------------------------------------------

    \78\ AP 42, Fifth Edition, Volume 1, Chapter 1: External
Sources, Section 1.4, Natural Gas Combustion, available here:
https://www3.epa.gov/ttn/chief/ap42/ch01/final/c01s04.pdf.
---------------------------------------------------------------------------

III. Proposed Action

    We are proposing to approve Louisiana's Regional Haze SIP revision
submitted on February 10, 2017, with the exception of the portion
related to the Entergy Nelson facility. We propose to approve the BART
determination for Michoud based on the draft permit, and note that we
expect the proposed permit removing Units 2 and 3 to be final before we
take final action to approve this portion of the 2017 Louisiana
Regional Haze SIP. Alternatively, LDEQ could submit another enforceable
document to ensure that Units 2 and 3 cannot restart without a BART
analysis and emission limits, or demonstrate the units have been
deconstructed to the point that they cannot restart without obtaining a
new NSR permit, making them not operational during the timeframe for
BART eligibility. Additionally, final approval of Louisiana's reliance
on CSAPR to satisfy NOX BART for EGUs is contingent upon our
finalization of the separate rulemaking, proposed on November 10, 2016
(81 FR 78954), that proposed to find that CSAPR continues to be better
than BART. Once we take final action on our proposed approval of
Louisiana's 2016 SIP revision addressing non-EGU BART,\79\ this
proposal, and a future proposed action to address SO2 and PM
BART for the Entergy Nelson facility, we will have fulfilled all
outstanding obligations with respect to the Louisiana regional haze
program for the first planning period.
---------------------------------------------------------------------------

    \79\ 81 FR 74750 (October 27, 2016).
---------------------------------------------------------------------------

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, the

EPA's role is to approve state choices, provided that they meet the
criteria of the CAA. Accordingly, this action merely proposes to
approve state law as meeting Federal requirements and does not impose
additional requirements beyond those imposed by state law. For that
reason, this action:

     Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Orders
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January
21, 2011);
     Does not impose an information collection burden under
the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et
seq.);
     Is certified as not having a significant economic
impact on a substantial number of small entities under the
Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly
or uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action
based on health or safety risks subject to Executive Order 13045 (62
FR 19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C.
272 note) because it does not involve technical standards; and
     Does not provide EPA with the discretionary authority
to address, as appropriate, disproportionate human health or
environmental effects, using practicable and legally permissible
methods, under Executive Order 12898 (59 FR 7629, February 16,
1994).

In addition, the SIP is not approved to apply on any Indian reservation
land or in any other area where EPA or an Indian tribe has demonstrated
that a tribe has jurisdiction. In those areas of Indian country, the
proposed rule does not have tribal implications and will not impose
substantial direct costs on tribal governments or preempt tribal law as
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects in 40 CFR Part 52

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

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

    Dated: May 1, 2017.
Samuel Coleman,
Acting Regional Administrator, Region 6.
[FR Doc. 2017-10108 Filed 5-18-17; 8:45 am]
BILLING CODE 6560-50-P