allowances or authorizations to emit equal to emissions, and allows the
owners and operators of sources and other entities to purchase, sell,
and transfer allowances. The Texas SO2 Trading Program is
modeled after the EPA's CSAPR SO2 Group 2 Trading Program,
and we are taking final action to affirm that the Program satisfies the
requirements of 51.308(e)(2)(vi). Similar to the CSAPR SO2
Group 2 Trading Program, the Texas SO2 Trading Program sets
an SO2 emission budget for affected units and sources in the
State of Texas. Authorizations to emit SO2, known as
allowances, are allocated to affected units. The Texas SO2
Trading Program provides flexibility to affected units and sources by
allowing units and sources to determine their own compliance path; this
includes adding or operating control technologies, upgrading or
improving controls, switching fuels, and using allowances. Sources can
buy and sell allowances and bank (save) allowances for future use so
long as each source holds enough allowances to account for its
emissions of SO2 by the allowance transfer deadline shortly
after the end of the compliance period.
    Section 51.308(e)(2)(vi)(A). This provision requires applicability
provisions defining the sources subject to the program. The State (or
EPA) must demonstrate that the applicability

provisions (including the size criteria for including sources in the
program) are designed to prevent any significant potential shifting
within the State of production and emissions from sources in the
program to sources outside the program. The October 2017 final rule and
the August 2018 proposal affirming that rule discuss the provisions of
the Texas SO2 Trading Program that satisfy Sec.
51.308(e)(2)(vi)(A).\103\ In this final action, we are making
amendments to some of these provisions, as discussed in section
III.A.1. We are terminating the opt-in provisions by removing sections
97.904(b), 97.911(b), and 97.921(d) from the regulations, and we are
making a minor correction to the Texas SO2 Trading Program
to relabel ``Newman unit 4,'' which is already participating in the
Texas SO2 Trading Program, as its components: ``Newman unit
**4'' and ``Newman unit **5.'' We are taking final action to find that
with these amendments, the Texas SO2 Trading Program
continues to have applicability provisions that satisfy Sec.
51.308(e)(2)(vi)(A).
---------------------------------------------------------------------------

    \103\ See 82 FR at 48360 and 83 FR at 43602.
---------------------------------------------------------------------------

    Section 51.308(e)(2)(vi)(B). This provision requires allowance
provisions ensuring that the total value of allowances (in tons) issued
each year under the program will not exceed the emissions cap (in tons)
on total annual emissions from the sources in the program. 40 CFR
Section 97.921 establishes how the Administrator will record the
allowances for the Texas SO2 Trading Program and ensures
that the Administrator will not record more allowances than are
available under the program consistent with 40 CFR 51.308(e)(2)(vi)(B).
    Sections 51.308(e)(2)(vi)(C)-(E). The provisions of sections
51.308(e)(2)(vi)(C)-(E) require monitoring provisions providing for
consistent and accurate measurements of emissions from sources in the
program to ensure that each allowance actually represents the same
specified tonnage of emissions and that emissions are measured with
similar accuracy at all sources in the program; recordkeeping
provisions that ensure the enforceability of the emissions monitoring
provisions and other program requirements; and reporting provisions
requiring timely reporting of monitoring data with sufficient frequency
to ensure the enforceability of the emissions monitoring provisions and
other program requirements and the ability to audit the program. The
monitoring, recordkeeping, and reporting provisions for the Texas
SO2 Trading Program at 40 CFR 97.930-97.935 are consistent
with those requirements in the CSAPR SO2 Group 2 Trading
Program. The provisions in 40 CFR 97.930-97.935 require the subject
units to comply with the monitoring, recordkeeping, and reporting
requirements for SO2 emissions in 40 CFR part 75, thereby
satisfying the requirements of 51.308(e)(2)(vi)(C)-(E).
    Section 51.308(e)(2)(vi)(F). This provision requires tracking
system provisions which provide for a tracking system that is publicly
available in a secure, centralized database to track in a consistent
manner all allowances and emissions in the program. The EPA is
implementing the Texas SO2 Trading Program using the
Allowance Management System, which provides a consistent approach to
implementation and tracking of allowances and emissions for the EPA,
subject sources, and the public consistent with the requirements of 40
CFR 51.308(e)(2)(vi)(F).
    Section 51.308(e)(2)(vi)(G). This provision requires authorized
account representative provisions ensuring that the owners and
operators of a source designate one individual who is authorized to
represent the owners and operators in all matters pertaining to the
trading program. The requirements at 40 CFR 97.913-97.918 for
designated and alternate designated representatives are consistent with
the requirements of 40 CFR 51.308(e)(2)(vi)(G) and are also consistent
with the EPA's other trading programs under 40 CFR part 97.
    Section 51.308(e)(2)(vi)(H). This provision requires allowance
transfer provisions providing procedures that allow timely transfer and
recording of allowances, minimize administrative barriers to the
operation of the allowance market, and ensure that such procedures
apply uniformly to all sources and other potential participants in the
allowance market. Allowance transfer provisions for the Texas
SO2 Trading Program at 40 CFR 97.922 and 97.923 provide
procedures that allow timely transfer and recording of allowances;
these provisions will minimize administrative barriers to the operation
of the allowance market and ensure that such procedures apply uniformly
to all sources and other potential participants in the allowance
market, consistent with 40 CFR 51.308(e)(2)(vi)(H).
    Section 51.308(e)(2)(vi)(I). This provision requires compliance
provisions prohibiting a source from emitting a total tonnage of a
pollutant that exceeds the tonnage value of its allowance holdings,
including the methods and procedures for determining whether emissions
exceed allowance holdings. The provision requires that such method and
procedures apply consistently from source to source. Compliance
provisions for the Texas SO2 Trading Program at 40 CFR
97.924 prohibit a source from emitting a total tonnage of
SO2 that exceeds the tonnage value of its SO2
allowance holdings as required by 40 CFR 51.308(e)(2)(vi)(I).
    Section 51.308(e)(2)(vi)(J). This provision requires penalty
provisions providing for mandatory allowance deductions for excess
emissions that apply consistently from source to source. Additionally,
the tonnage value of the allowances deducted must equal at least three
times the tonnage of the excess emissions. The Texas SO2
Trading Program includes automatic allowance surrender provisions at 40
CFR 97.924(d) that apply consistently from source to source and the
tonnage value of the allowances deducted shall equal at least three
times the tonnage of the excess emissions, consistent with the penalty
provisions at 40 CFR 51.308(e)(2)(vi)(J).
    Section 51.308(e)(2)(vi)(K). For a trading program that allows
banking of allowances, this provision requires provisions clarifying
any restrictions on the use of these banked allowances. The Texas
SO2 Trading Program provides for banking of allowances under
40 CFR 97.926; Texas SO2 Trading Program allowances are
valid for compliance in the control period of issuance or may be banked
for use in future control periods, consistent with 40 CFR
51.308(e)(2)(vi)(K).
    Section 51.308(e)(2)(vi)(L). This provision requires program
assessment provisions providing for periodic program evaluation to
assess whether the program is accomplishing its goals and whether
modifications to the program are needed to enhance performance of the
program. The CAA and EPA's implementing regulations require
comprehensive periodic revisions of implementation plans for regional
haze under 40 CFR 51.308(f) and periodic review of the state's regional
haze approach under 40 CFR 51.308(g) to evaluate progress towards the
reasonable progress goals for Class I areas located within the state
and Class I areas located outside the State affected by emissions from
within the state. Because the Texas SO2 Trading Program is a
BART-alternative and part of the long-term strategy for Texas' Regional
Haze obligations, this program will be reviewed in each comprehensive
periodic revision and progress report. We anticipate these revisions
and progress reports will provide the information needed to assess
program

performance, as required by 40 CFR 51.308(e)(2)(vi)(L).
    Based on the analysis presented here, EPA is taking final action to
affirm our determination that the Texas SO2 Trading Program,
as amended in this final action, meets the requirements of 40 CFR
51.308(e)(2) as a BART alternative for SO2 to satisfy Texas'
Regional Haze obligations.
3. PM BART
    We are taking final action to affirm our October 2017 approval of
the portion of the Texas Regional Haze SIP that determined that PM BART
emission limits are not required for any Texas EGUs. The majority of
Texas' BART-eligible EGUs rely on BART alternatives for both
SO2 and NOX emissions (or have otherwise been
determined to be not subject to BART). We approved Texas' pollutant-
specific screening analysis for PM as appropriate and consistent with a
2006 guidance document in which the EPA stated that pollutant-specific
screening can be appropriate where a state is relying on a trading
program as a BART alternative to address both NOX and
SO2 BART.\104\ All of the BART-eligible sources
participating in the SO2 intrastate trading program have
visibility impacts from PM alone below the subject-to-BART threshold of
0.5 deciviews (dv).105 106 Furthermore, the BART-eligible
sources not participating in the intrastate trading program were
screened out of BART for all visibility impairing pollutants.
Therefore, we are finalizing our affirmation of our prior approval that
no Texas EGUs are subject to PM BART and that PM BART emission limits
are not required for any Texas EGUs under EPA's 2006 guidance.
---------------------------------------------------------------------------

    \104\ See discussion in Memorandum from Joseph Paisie to Kay
Prince, ``Regional Haze Regulations and Guidelines for Best
Available Retrofit Technology (BART) Determinations,'' July 19,
2006.
    \105\ Our technical evaluation of Texas' PM screening approach
in the 2009 Texas Regional Haze SIP submittal was originally
presented in a December 16, 2014 proposal. See 79 FR 74817, 74848-49
(Dec. 16, 2014). As noted in our August 2018 proposal, the basis of
our affirmation of our approval of Texas' PM screening approach
remains consistent with the technical evaluation we provided at the
time. See 83 FR 43586, at 43593.
    \106\ Stryker Creek Unit ST2 is covered by CSAPR for
NOX and by the SO2 trading program but was not
included in the 2009 Regional Haze SIP. In our August 2018 proposal,
we explained that based on our own evaluation in the January 2017
proposal and October 2017 final rule, we determined that the
visibility impact attributable to PM emissions from Stryker Creek
Unit ST2 is a small fraction (roughly 1%) of the 0.786 dv aggregate
impact of the unit's emissions from all pollutants. This is well
below the subject-to-BART threshold of 0.5 dv. See 83 FR 43586, at
43593.
---------------------------------------------------------------------------

4. Reasonable Progress
    This final action addressing the BART requirements is part of the
long-term strategy for Texas and will contribute to making reasonable
progress toward the goal of natural visibility conditions at Texas' and
downwind Class I areas. However, the EPA is not determining at this
time that this final action fully resolves the EPA's outstanding
obligations with respect to reasonable progress that resulted from the
Fifth Circuit's remand of our reasonable progress FIP.\107\ We intend
to take a separate, future action to address the Fifth Circuit's
remand.
---------------------------------------------------------------------------

    \107\ Order, Texas v. EPA, 16-60118 (5th Cir. Mar. 22, 2017).
---------------------------------------------------------------------------

B. Interstate Transport of Pollutants That Affect Visibility

    We are taking final action to affirm our finding that Texas'
participation in CSAPR to satisfy NOX BART and our
SO2 intrastate trading program, as amended in today's final
action, fully addresses Texas' interstate visibility transport
obligations for the following six NAAQS: (1) 1997 8-hour ozone; (2)
1997 PM2.5 (annual and 24 hour); (3) 2006 PM2.5
(24-hour); (4) 2008 8-hour ozone; (5) 2010 1-hour NO2; and
(6) 2010 1-hour SO2. The basis for this final action is our
determination in the October 2017 FIP that the regional haze measures
in place for Texas are adequate to ensure that emissions from the State
do not interfere with measures to protect visibility in nearby states,
because the emission reductions are consistent with the level of
emissions reductions relied upon by other states during interstate
consultation under 40 CFR 51.308(d)(3)(i)-(iii) and when setting their
reasonable progress goals.\108\ As discussed in our August 2018
affirmation proposal, the 2009 Texas Regional Haze SIP relied on
participation in CAIR to meet SO2 and NOX BART
requirements for Texas EGUs. Under CAIR, Texas EGU sources were
projected to emit approximately 350,000 tons of SO2
annually.\109\ These are the 2018 EGU emission projections used by
CENRAP for Texas that other states potentially impacted by emissions
from Texas sources agreed upon during interstate consultation and
relied on in their regional haze SIPs. In today's final action, we are
finalizing four revisions to strengthen the Texas SO2
Trading Program and increase its consistency with CSAPR, including the
addition of an assurance level consistent with the 2012 CSAPR
demonstration. As discussed elsewhere in today's final action, Texas
EGU annual SO2 emissions for sources covered by the trading
program will be constrained by the assurance level of 255,083 tons.
Including an estimated 35,000 tons per year of emissions from units not
covered by the Texas SO2 Trading Program yields 290,083 tons
of SO2, which is well below the 350,000-ton emissions
projection for 2018 for Texas sources under CAIR or the 317,100-ton
emissions level assumed for Texas sources under CSAPR participation in
the BART-alternative sensitivity analysis utilized for the 2012 CSAPR
Better-than-BART determination. Additionally, the October 2017 FIP
relies on CSAPR for ozone season NOX as an alternative to
EGU BART for NOX, which exceeds the NOX emission
reductions that would have been realized from Texas EGUs under CAIR and
that other states relied upon during interstate consultation for the
first planning period.\110\ Because the revisions to the Texas
SO2 Trading Program we are finalizing in today's final
action ensure emission reductions consistent with and below the
emission levels relied upon by other states during interstate
consultation, we find that these revisions provide further support for
our earlier finding that the BART alternative in the October 2017 FIP
results in emission reductions adequate to satisfy the requirements of
CAA section 110(a)(2)(D)(i)(II) with respect to visibility for the six
identified NAAQS.
---------------------------------------------------------------------------

    \108\ See 2009 Texas Regional Haze SIP, section 4.3 titled
``Consultations On Class I Areas In Other States.'' The submittal
can be found at www.regulations.gov, Docket ID EPA-R06-OAR-2016-
0611, Document ID EPA-R06-OAR-2016-0611-0002.
    \109\ See section 10 of the 2009 Texas Regional Haze SIP. Table
10-7 shows that under CAIR, the 2018 emission from Texas EGUs were
projected to be approximately 350,000 tons SO2. The SIP
submittal can be found in www.regulations.gov, Docket ID EPA-R06-
OAR-2016-0611, Document ID EPA-R06-OAR-2016-0611-0002.
    \110\ Under CAIR, Texas had an annual 2009 CAIR Phase 1 budget
of 181,017 tons of NOX and an annual 2015 CAIR Phase 2
budget of 150,845 tons of NOX. See Section 11, Table 11-
15 of the 2009 Texas Regional Haze SIP. The SIP submittal can be
found at www.regulations.gov, Docket ID EPA-R06-OAR-2016-0611,
document ID EPA-R06-OAR-2016-0611-0002. The 2018 EGU emission
projections for NOX used by CENRAP for Texas, which other
states potentially impacted by emissions from Texas sources agreed
upon during interstate consultation and relied on in their regional
haze SIPs, were approximately 160,000 tons. In contrast, under the
CSAPR ozone season NOX trading program, Texas' 2017
NOX ozone season budget is 52,301 tons of NOX.
See 81 FR 74504, 74508 (Oct. 26, 2016).
---------------------------------------------------------------------------

IV. Summary and Responses to Significant Issues Raised by Commenters

    We received both written and oral comments at the public hearings
we held in Austin and Dallas. We also

received written comments on the August 27, 2018 affirmation proposed
action and the November 14, 2019 supplemental proposed action. The full
text of comments received is included in the publicly posted docket
associated with this action at www.regulations.gov. We reviewed all
public comments that we received. Below we provide a summary of the
most significant comments and our responses. A complete summary of all
of the comments we received, and our responses thereto are contained in
a separate document titled Response to Comments, which is found in the
docket associated with this final action.

A. Texas SO2 Trading Program as a BART Alternative

    Comment: We received one comment asserting that in promulgating the
Texas SO2 Trading Program as a BART alternative in our
October 2017 FIP and in affirming the trading program in our August
2018 proposal, EPA did not properly demonstrate that the trading
program meets the requirements for an alternative to BART for
SO2 because EPA did not compare the alternative to source-
specific BART in Texas. The commenter asserted that the Regional Haze
Rule at 40 CFR 51.308(e)(2) specifies that BART and associated emission
reductions achievable for each source within the State subject to BART
and covered by the alternative program must be evaluated first for the
purpose of comparing to the BART alternative and determining whether
the alternative makes greater reasonable progress than BART. The
commenter also noted that the Regional Haze Rule at Sec.
51.308(e)(2)(i)(C) provides that the only exception to this requirement
is when the emissions trading program or other alternative measure has
been designed to meet a requirement other than BART and that in such
cases, EPA may analyze BART for similar types of sources within a
source category instead of on a source-specific basis. The commenter
asserted that in promulgating the Texas SO2 Trading Program,
EPA did not properly demonstrate that the trading program is better
than BART and meets the requirements for an alternative to BART because
EPA has not determined which units are subject to BART, and did not
provide an analysis of BART at each source subject to BART and covered
by the trading program to compare against the trading program.
According to the commenter, even if presumptive BART levels were an
appropriate assumption that is not outdated, EPA would still be
required to compare the trading program directly to presumptive BART,
which it has not done. The commenter also contended that EPA's approach
of comparing the intrastate trading program to Texas' participation in
the SO2 trading program under CSAPR is not appropriate
because EPA withdrew Texas from the CSAPR program for SO2
and thus CSAPR cannot lawfully be BART for SO2 for Texas
EGUs.
    The commenter also disagreed with EPA's position that the trading
program was designed to meet requirements other than BART, namely the
interstate transport requirements and the long-term strategy
provisions. The commenter asserted that even if the trading program had
indeed been designed to meet requirements other than BART, this would
still not authorize EPA to completely forego analyzing BART for the
sources subject to BART and covered by the trading program.
    Response: As explained in our August 27, 2018 proposal, in addition
to being a sufficient alternative to BART, the trading program is
designed to secure reductions consistent with visibility transport
requirements.\111\ As allowed by the requirements for a BART
alternative in Sec.  51.308(e)(2)(i)(C), we are exercising the
exception allowed when the alternative measure ``has been designed to
meet a requirement other than BART (such as the core requirement to
have a long-term strategy to achieve the reasonable progress goals
established by States).'' See 40 CFR 51.308(e)(2)(i)(C). In such
circumstances, BART and associated emission reductions may be analyzed
for similar sources ``based on both source-specific and category-wide
information, as appropriate.'' When promulgating the 2012 CSAPR Better-
than-BART rule, the EPA relied on an analysis of BART in CSAPR states
and a demonstration showing that CSAPR would result in greater
reasonable progress than BART under the test in 40 CFR 51.308(e)(3). In
that analysis, EPA utilized simplified assumptions regarding
``presumptive'' BART limits at BART-eligible sources. This analysis was
conducted on a category-wide basis (all fossil fuel-fired EGUs). See 77
FR 33642, 33649-50 (June 7, 2012). This analysis satisfied
51.308(e)(2)(i)(C) because CSAPR was designed to meet the requirements
of CAA section 110(a)(2)(D)(i)(I) (sometimes referred to as ``good
neighbor'' obligations) for certain NAAQS pollutants. EPA finds that
reliance on the category-wide BART analysis from the 2012 CSAPR Better-
than-BART demonstration is appropriate here, because, although the
Texas program is not designed to meet good neighbor obligations under
section 110(a)(2)(D)(i)(I), it is designed to meet separate CAA
requirements for interstate visibility transport, as explained in
section III.B above. This satisfies the condition in 51.308(e)(2)(i)(C)
for using category-wide information such as presumptive BART limits in
analyzing the Texas SO2 Trading Program. Thus, the BART
determinations derived from that CSAPR Better-than-BART demonstration
are an appropriate BART benchmark for comparison against the Texas
SO2 Trading Program given that the Texas SO2
Trading Program is modeled on the CSAPR trading programs. In this
action, we are relying, in part, on that same 2012 CSAPR Better-than-
BART demonstration to show that the clear weight of evidence
demonstrates that the Texas SO2 Trading Program, which is
modeled on the CSAPR trading programs, will provide for greater
reasonable progress than BART in Texas. Indeed, the anticipated maximum
potential SO2 emissions in Texas under the Texas
SO2 Trading Program BART alternative are less than the
SO2 emission levels from Texas EGUs that were forecast in
the demonstration for Texas EGU emissions assuming their participation
in the CSAPR SO2 trading program. Under CSAPR, the total
allocations for all existing EGUs in Texas were 279,740 SO2
tons, the total state budget including the amounts of allowances set
aside for potential allocation to new units was 294,471 tons, and the
assurance level was 347,476 tons. The level of emissions assumed for
Texas EGUs in the BART alternative sensitivity analysis utilized for
the 2012 CSAPR Better-than-BART determination is 317,100 SO2
tons.\112\ By comparison, the Texas SO2 Trading Program has
a budget of 238,395 SO2 tons, and we are finalizing an
assurance level of 255,083 tons in this action. In light of the three-

for-one penalty surrender ratio imposed on emissions exceeding the
255,083-ton assurance level, the assurance level represents the highest
annual SO2 emissions anticipated from units subject to the
Texas program. In reality, in light of ongoing changes in the electric-
generating sector in Texas, there is a reasonable expectation that
actual emissions under the Texas program would remain well below the
assurance level. We are also finalizing a more conservative (i.e.,
higher) estimate of 35,000 annual SO2 tons as the projected
emissions from Texas units that would have been in the CSAPR program
but are not in the Texas SO2 Trading Program. This more
conservative estimate is based on these units' maximum annual emission
level of 34,129 tons over the past five years (2014-2018) and taking
into consideration that several of these units have recently shut down
or have been announced for shutdown in the near future.\113\ Adding
that amount to the Texas SO2 Trading Program's assurance
level of 255,083 tons yields 290,083 tons. Assuming this figure
represents a firm upper bound on annual SO2 emissions from
the relevant EGUs in Texas under the Texas SO2 Trading
Program, this is less than the 317,100-ton figure EPA had demonstrated
was acceptable in the original 2012 CSAPR Better-than-BART analysis.
---------------------------------------------------------------------------

    \111\ 83 FR 43586, at 43597.
    \112\ For the projected annual SO2 emissions from
Texas EGUs, see Technical Support Document for Demonstration of the
Transport Rule as a BART Alternative, Docket ID No. EPA-HQ-OAR-2011-
0729-0014 (December 2011) (2011 CSAPR/BART Technical Support
Document at Table 2-4,), available in the docket for this action.
Certain CSAPR budgets were increased after promulgation of the CSAPR
final rule (and the increases were addressed in the 2012 CSAPR/BART
sensitivity analysis memo. See memo entitled ``Sensitivity Analysis
Accounting for Increases in Texas and Georgia Transport Rule State
Emissions Budgets,'' Docket ID No. EPA-HQ-OAR-2011-0729-0323 (May
29, 2012), available in the docket for this action. The increase in
the Texas SO2 budget was 50,517 tons which, when added to
the Texas SO2 emissions projected in the CSAPR + BART-
elsewhere scenario of 266,600 tons, yields total potential
SO2 emissions from Texas EGUs of approximately 317,100
tons.
    \113\ 84 FR 61853.
---------------------------------------------------------------------------

    Comment: The commenter asserted that it was not appropriate for EPA
to conclude that because CSAPR achieves greater reasonable progress
than BART when averaged across all affected states that this
necessarily means that CSAPR achieves greater reasonable progress than
BART in Texas. The commenter asserted that the legal test that EPA used
during the original ``CSAPR Better-than-BART'' rulemaking is
fundamentally different than the test EPA must use in assessing whether
the Texas SO2 Trading Program is better than BART. The
commenter asserted that in making its determination that CSAPR achieves
greater reasonable progress than BART under 40 CFR 51.308(e)(3), EPA
was required to demonstrate that visibility does not decline in any
Class I area and that there is an overall improvement in visibility,
determined by comparing the average differences between BART and the
alternative over all affected Class I areas. The commenter argued that
since EPA averaged the visibility improvement from CSAPR over all the
affected Class I areas in the eastern half of the country in the CSAPR
Better-than-BART determination, Texas was able to take advantage of
reductions from other states without having to reduce its
SO2 emissions as much as it would have had to do under
source-by-source BART. The commenter argued that in contrast to the
CSAPR Better-than-BART determination, the legal test required under
Sec. Sec.  51.308(e)(2)(i) and 51.308(e)(3) to demonstrate that the
Texas SO2 Trading Program is better than BART cannot rest on
improvements from CSAPR in other states. The commenter argued that EPA
must instead demonstrate that the Texas SO2 Trading Program
is better than BART in Texas alone by examining the visibility
improvement at only the Class I areas affected by Texas sources.
    Response: We disagree that EPA must demonstrate that the Texas
SO2 Trading Program is better than BART by examining
visibility improvement at only Class I areas in Texas and Class I areas
in other states affected by Texas sources. As explained in our proposal
affirming the Texas SO2 Trading Program, the 2012
demonstration that CSAPR, as finalized and amended in 2011 and 2012,
meets the Regional Haze Rule's criteria for a demonstration of greater
reasonable progress than BART is also the primary evidence that the
Texas trading program achieves greater reasonable progress than
BART.\114\ In the 2012 CSAPR Better-than-BART rule, the EPA relied on
an analytic demonstration that included an air quality modeling study
showing that CSAPR results in greater improvements in average
visibility across all affected Class I areas as compared to adopting
source-specific BART. Our finding with respect to the Texas program
relies on the demonstration underlying our CSAPR Better-than-BART Rule
and our 2017 CSAPR Better-than-BART affirmation (including the basis
for our denial of a petition for reconsideration in the latter,\115\ as
discussed in section I.D of the preamble). Thus, we find that given the
particular circumstances in this case, we are not required to focus
only on Class I areas in Texas and Class I areas in other states
affected by Texas sources. Rather, we are assessing the Texas program
in the context of the larger CSAPR Better-than-BART analysis. We find
that due to the specific circumstances in this case, as described
above, it is reasonable and appropriate to consider improvements in
average visibility across all affected Class I areas in our assessment
of the Texas SO2 Trading Program to demonstrate that it is
better than BART. The amendments to the Texas SO2 Trading
Program we are finalizing in this action ensure that EGU emissions
under the Texas program will remain well below the amount assumed in
the BART-alternative sensitivity analysis utilized for the 2012 CSAPR
Better-than-BART determination (i.e., 317,100 tons), and thus
visibility levels at Class I areas impacted by sources in Texas are
anticipated to be at least as good as (and likely better than) the
levels projected under Texas participation in the larger CSAPR
SO2 trading program.
---------------------------------------------------------------------------

    \114\ 83 FR 43586, at 43599.
    \115\ See U.S. EPA, Denial of Petition for Partial
Reconsideration of ``Interstate Transport of Fine Particulate
Matter: Revision of Federal Implementation Plan Requirements for
Texas'' (82 FR 45481; Sept. 29, 2017) (EPA-HQ-OAR-2016-0598). A copy
of the denial of petition letter sent to the petitioners and the
denial of petition Notice of Availability (NOA) published in the
Federal Register are available at Docket ID EPA-HQ-OAR-2016-0598.
---------------------------------------------------------------------------

    Comment: We received one comment that asserted that EPA's reliance
on CSAPR to design the Texas SO2 Trading Program as a BART
alternative is not appropriate because in doing so, EPA did not account
for new circumstances or update emissions and other data, which the
commenter claimed EPA typically does when evaluating BART. The
commenter asserted that if EPA had taken the same technical approach it
has taken in other regional haze actions of using the most up-to-date
data, this would have changed the allowance distribution of the Texas
SO2 Trading Program. For instance, the commenter argued that
in developing the Texas SO2 Trading Program, EPA should have
taken into account the retirements of Welsh 2, Big Brown Units 1 and 2,
Monticello Units 1, 2, and 3, and Sandow 4 and 5. Similarly, the
commenter asserted the Texas SO2 Trading Program should have
included rule provisions for properly dealing with the impending
retirement of the two JT Deely units instead of the current method of
addressing retired allowances, which the commenter claimed provides no
incentive to reduce SO2 emissions. Additionally, the
commenter noted that EPA assigned allocations under CSAPR on the basis
of a unit's heat input from 2006-2010 and its emissions from 2003-2010
utilizing a detailed ten-step approach based on the heat input and
emissions from those periods. The commenter claimed that EPA should
have re-applied the same allocation methodology it used for CSAPR using
updated information, and that if EPA had done so, the allocations in
many instances would have changed significantly. In support of this
argument, the commenter performed this analysis using the same number
of years as in the original CSAPR methodology but shifted the year
ranges forward to include updated information.

The commenter asserted that two cases were analyzed. In the first case,
the commenter did not remove retired units and used the original CSAPR
methodology to revise the CSAPR allocations while using updated data.
In this case, because none of the retired units were removed, the total
allocations remained at 238,393 tons. However, the commenter asserted
that because the emissions and heat inputs changed with the updated
data, almost every unit's allocations changed, in some cases by more
than 3,000 tons. In the second case, the commenter asserted that
retired units were removed, but the JT Deely units were retained. The
commenter asserted that because of the removal of retired units and
because of the updated emissions and heat inputs, almost every unit's
allocations changed, resulting in a reduction of allocations from
238,393 tons to 176,332 tons. The commenter noted that these additional
62,061 tons in unit allocations that resulted from EPA not using the
most updated data in the allocation methodology and not removing
retired units should not be moved into the Supplemental Allowance Pool
as Section 97.911(a)(2) of the Texas SO2 Trading Program
provides. The commenter argued that these allowances should never have
been in the allowance pool in the first place. The commenter concluded
that the analysis performed by the commenter demonstrates that if EPA
had updated the emissions data and heat input data using the original
CSAPR methodology and removed the retired units' allocations, the Texas
SO2 Trading Program would not include excess allowances,
which the commenter claimed disincentivizes SO2 emissions
reductions.
    Response: As stated in responses to several other comments in this
final action and in our Response to Comments document found in the
docket for this action, we disagree that in developing a specific
trading program, EPA must incorporate new design features, particularly
when other legal and policy considerations weigh in favor of making the
program similar in design to a specific previous program that does not
include those design features. Likewise, EPA is not required to
incorporate new design features that may be suggested by a commenter
and is not required to update every data element used in the
rulemaking. In this instance, the Texas SO2 Trading Program
was designed to qualify as a BART alternative in light of EPA's
previous determinations regarding permissible BART alternatives, and
for that reason was designed to be as similar as possible to the CSAPR
SO2 program. Both the amounts of the initial allocations to
units under the Texas SO2 Trading Program and the treatment
of the allocations to units that have been retired for at least five
years are directly based on the analogous provisions in the CSAPR
SO2 program. As discussed in response to another comment on
the Texas SO2 Trading Program's Supplemental Allowance Pool,
in those aspects of the overall allocation methodology where the Texas
SO2 Trading Program allowance allocation provisions deviate
from the CSAPR SO2 program allowance allocation provisions,
the Texas SO2 Trading Program is generally more, not less,
stringent.
    With respect to the commenter's point that the amount of the CSAPR
SO2 program budget for Texas was initially determined based
on our assessments of the state's interstate transport obligations at
the time of the CSAPR rulemaking, we agree with the statement but do
not consider the point relevant to this final action. The origins of
the CSAPR budgets are immaterial to this action. Along with certain
budget adjustments that were addressed through sensitivity analyses,
the CSAPR budgets were used in our 2012 CSAPR Better-than-BART
determination and therefore remain relevant for purposes of our
determination in this action that the Texas SO2 Trading
Program qualifies as a BART alternative in the context of the 2012
CSAPR Better-than-BART determination.
    With respect to the commenter's identification of alternative
possible distributions of allowances among the units covered by the
program, we do not believe that altering the distribution of allowances
while leaving the total number of allowances the same would change the
stringency of the program, although it could address concerns regarding
whether the distribution among the sources is equitable. As none of the
sources covered by the program have raised equity concerns about the
initial allocations, and given that we do not understand the commenter
to be raising such concerns, we see no reason to redistribute the
initial allocations. We address the comments regarding the stringency
of the program cap elsewhere.
    With regard to the commenter's position that allowances allocated
to units that retire should be eliminated from the budget instead of
being reallocated, that is of course an option in designing a trading
program, but it is not a requirement, and it is not a feature of the
CSAPR SO2 program on which the Texas SO2 Trading
Program was modeled. We were not required and did not find it necessary
to take such an approach in the Texas SO2 Trading Program in
order to ensure that the program qualifies as a BART alternative in the
context of the 2012 and 2017 CSAPR Better-than-BART determinations.
    Comment: We received comments from the State and affected sources
in support of our affirmation that the October 2017 Regional Haze FIP
satisfies Texas' obligations for BART and in support of our
determination that the intrastate SO2 trading program for
certain EGUs in Texas is an appropriate BART alternative and satisfies
all SO2 BART requirements. Several affected sources also
provided comments in support of the October 2017 SO2 trading
program over the adoption of a source-by-source approach to address the
BART requirements for units subject to BART in Texas. One affected
source asserted that the trading program will allow operational
flexibility in complying with BART obligations and another affected
source asserted that it is appropriate for EPA to respect Texas'
preference to meet BART compliance through a BART alternative rather
than source-specific BART.
    Response: We appreciate the commenter's support of our FIP that
establishes an intrastate trading program that caps emissions of
SO2 from certain EGUs in Texas and includes the
determination that this program meets the requirements for an
alternative to BART for SO2.
    Comment: We received one comment that argued that EPA's reliance on
the CSAPR Better-than-BART demonstration is based on the false premise
that the Texas SO2 Trading Program is functionally
equivalent to CSAPR. The commenter asserted that the Texas
SO2 Trading Program is not sufficiently similar to CSAPR for
a comparison between Texas' overall emissions under the Texas
SO2 Trading Program versus CSAPR to suffice for a weight of
evidence determination. In support of the claim that the Texas
SO2 Trading Program and CSAPR are not sufficiently similar,
the commenter pointed to the exclusion from the Texas SO2
Trading Program of a number of Texas EGUs that were covered under CSAPR
and argued that EPA presented no real analysis of the visibility
impacts of these excluded units. The commenter asserted that for some
of these excluded units that have existing scrubbers or other types of
SO2 control, such as Oklaunion, W.A. Parish 8, Oak Grove
Units 1 and 2, Twin Oaks Units 1 and 2, and Sandy Creek, EPA should
have

evaluated possible upgrades to existing SO2 controls.
    The commenter also argued that there are flaws in how EPA performed
its Q/d analysis that constitute arbitrary deviations from EPA's Q/d
testing methodology in past regional haze actions and claimed that the
deviations were made in order to exclude certain units from the Texas
SO2 Trading Program. For instance, the commenter asserted
that EPA's decision to base the Q/d analysis on 2009 emissions was
arbitrary and claimed that no rationale was provided for selecting that
year of data other than EPA noting that it already had this emissions
data available from a previous analysis. The commenter asserted that in
contrast to the Q/d analysis EPA used to identify sources to include in
the Texas SO2 Trading Program, in past regional haze
actions, EPA has typically considered a 3-5 year range of data to
account for data variability from year to year. The commenter also
asserted that the Twin Oaks facility had a Q/d greater than EPA's
stated threshold of 10 but it was nonetheless excluded on the basis
that EPA estimated that the Q/d of each of its individual units were
likely less than 10. The commenter claimed that EPA's decision to
deviate from its approach is arbitrary and was made in order to exclude
the Twin Oaks facility from the trading program. Similarly, the
commenter asserted that EPA's decision to exclude Oklaunion from the
trading program even though its Q/d was 85, which is much higher than
the EPA's stated threshold of 10, is arbitrary. The commenter asserted
that EPA's decision to exclude units that came online after 2009 on the
basis that these units would be permitted and constructed using
emission control technology determined under either BACT or LAER
review, was inappropriate given that EPA made no comparison between the
levels of control under BACT or LAER versus BART for these units. The
commenter argued that this comparison was necessary given that,
according to the commenter, BART has been demonstrably more stringent
than either BACT or LAER. The commenter also asserted that the opt-in
provision is yet another feature of the Texas SO2 Trading
Program that makes the trading program not functionally equivalent to
CSAPR, as EPA removed the opt-in provision in CSAPR.
    Response: We continue to believe that the Texas SO2
Trading Program will achieve SO2 emission levels that are
functionally equivalent to those that had been previously projected for
Texas' participation in the original CSAPR program and that our
reliance on the original CSAPR Better-than-BART determination for the
clear weight of evidence demonstration required under Sec.
51.308(e)(2)(i)(E) was thus appropriate in this case. What we mean by
the phrase ``functionally equivalent'' is that while the two programs
are not identical, the differences between the Texas SO2
Trading Program and CSAPR are either not significant or work to
demonstrate the relatively greater stringency of the Texas
SO2 Trading Program as compared to CSAPR. As the commenter
notes, in our August 27, 2018 proposal affirming the Texas
SO2 Trading Program, we listed several points that help
demonstrate the relative stringency of the Texas SO2 Trading
Program as compared to CSAPR.\116\ These points are summarized below:
---------------------------------------------------------------------------

    \116\ 83 FR 43586, at 43591.
---------------------------------------------------------------------------

     Covered sources under the Texas SO2 Trading
Program represent approximately 85% of CSAPR allocations for existing
units in Texas. Covered sources under the Texas SO2 Trading
Program represent 89% of all SO2 emissions from all Texas
EGUs in both 2016 and 2017.
     The remaining 11% of 2016 and 2017 emissions from Texas
EGUs not covered by the BART alternative come from gas units that
rarely burn fuel oil or from coal-fired units that on average are
better controlled for SO2 than the covered sources and
generally are less relevant to visibility impairment.\117\ As a result,
any shifting of generation to non-covered sources, as might occur if a
covered source were to reduce its operation in order to remain within
its SO2 emissions allowance allocation, is expected to
result in fewer emissions to generate the same amount of electricity.
---------------------------------------------------------------------------

    \117\ Id.
---------------------------------------------------------------------------

     We also noted that the non-inclusion of a large number of
gas-fired units that rarely burn fuel oil reduces the amount of
available allowances for such units that would typically and
collectively be expected to use only a fraction of their CSAPR
allowance allocations. Many of these sources typically emit at levels
much lower than their allocation level.
     Emissions projections under CAIR and CSAPR showed that
Texas sources were anticipated to purchase allowances from out-of-state
sources. In contrast to CSAPR, the Texas SO2 Trading Program
does not allow purchasing of allowances from out-of-state sources. This
will ensure that emissions reductions resulting from implementation of
the Texas SO2 Trading Program will take place in Texas
instead of a neighboring state. In this respect, implementation of the
Texas SO2 Trading Program can be expected to result in
greater visibility benefits at Texas Class I areas than CSAPR.
    Furthermore, in the final analysis for this action, we have updated
our emissions assumptions to be even more conservative (i.e., we assume
the potential for higher emissions) for units that were in the CSAPR
program but not covered by the Texas SO2 Trading Program. In
the August 2018 proposal, we had used an assumption that emissions from
these units could be as high as 27,500 tons per year.\118\ However, in
the updated analysis presented for comment in the November 2019 SNPRM,
we adjusted this assumption to 35,000 tons per year. This number
reflects emissions for the past five years (2014-2018), which EPA
regards as a conservative assumption for emissions performance from
these units. Even when this conservative figure is added to the highest
annual emissions anticipated from units under the Texas program,
255,083 tons per year (i.e., the assurance level for the program), the
total figure is 290,083 tons per year. As EPA explains in section
III.A.2 of the preamble for this action, that figure is still 27,019
tons below the 317,100 ton per year emissions level for Texas that EPA
assumed in the BART-alternative sensitivity analysis utilized for the
2012 CSAPR Better-than BART determination.
---------------------------------------------------------------------------

    \118\ 83 FR 43586, at 43602.
---------------------------------------------------------------------------

    Based on the above points and the fact that the combination of (1)
the source coverage for the Texas SO2 Trading Program, (2)
the total allocations for EGUs covered by the program, and (3) recent
and foreseeable emissions trends from those EGUs both covered and not
covered by the program will result in future EGU emissions in Texas
that are less than the SO2 emission levels forecast in the
2012 Better-than-BART demonstration for Texas EGU emissions assuming
CSAPR participation,\119\ it is not reasonable to expect that the Texas
SO2 Trading Program would result in less visibility benefit
in Texas Class I areas compared to Texas' participation in CSAPR. Thus,
we continue to believe that we have sufficiently demonstrated that
differences in source coverage between the Texas SO2 Trading
Program as amended in this final action and CSAPR are either not
significant or work to demonstrate the relative stringency of the Texas
SO2 Trading Program as compared to CSAPR.
---------------------------------------------------------------------------

    \119\ 83 FR 43586, at 43591.
---------------------------------------------------------------------------

    Our decision to exclude from the Texas SO2 Trading
Program certain units that were covered under CSAPR was not arbitrary
as the commenter

contends, but rather was generally based on both the results of a Q/d
analysis as well as the units' potential to impact visibility at Class
I areas based on our consideration of certain circumstances specific to
each unit. Based on our consideration of the above, we found it
appropriate to exclude certain units that were previously covered under
CSAPR from the Texas SO2 Trading Program. For example, some
units are already operating SO2 controls and we thus do not
consider the potential visibility impacts from these units to be
significant relative to those coal-fired EGUs participating in the
program, and we therefore excluded them from the Texas SO2
Trading Program. In some cases, relatively new units that began
operation after 2009 and have been permitted and constructed using
emission control technology determined under either Best Available
Control Technology (BACT) or Lowest Achievable Emission Rate (LAER)
review, as applicable. As we explained in our proposal affirming the
Texas SO2 Trading Program, because these newer units are
already operating BACT or LAER controls, we do not consider the
potential visibility impacts from these units to be significant
relative to those coal-fired EGUs participating in the program. The
commenter contends that in these cases, we should have compared the
levels of control under BACT or LAER versus BART for these units
because BART can in some cases be more stringent than either BACT or
LAER. However, given the much greater anticipated visibility impact
from uncontrolled coal-fired EGUs participating in the program, we
continue to believe that it is reasonable for us to focus our efforts
on these uncontrolled coal-fired EGUs while excluding the newer,
already controlled EGUs from the Texas SO2 Trading Program.
    The commenter specifically identifies Oklaunion, W.A. Parish Unit
8, Oak Grove Units 1 and 2, Sandy Creek Unit 1, and the Twin Oaks
facility as units that were covered under CSAPR, but which were
excluded from the Texas SO2 Trading Program. Although
Oklaunion has a Q/d greater than 10, we ultimately excluded Oklaunion
from the Texas SO2 Trading Program based on our
consideration that the facility consists of one coal-fired unit that is
not BART-eligible; annual emissions of SO2 in 2016 from this
source were 1,530 tons, which is less than 1% of the total annual
emissions for EGUs in the state; and annual SO2 emissions
were only 933 tons in 2017. In short, the most recent emissions from
this facility are small relative to other non-BART units included in
the program.\120\ And as noted in our November 2019 supplemental
proposal, American Electric Power announced in 2018 its plans to shut
down the Oklaunion Power Plant by September 2020.\121\ With regard to
W.A. Parish Unit 8, this unit is not BART-eligible, but is co-located
with BART-eligible units. Although we decided to include most coal-
fired units that are not BART-eligible but are co-located with BART-
eligible EGUs in the Texas SO2 Trading Program to prevent
any significant shifting of generation and SO2 emissions
from participating sources to non-participating sources within the same
facility, we decided not to include W.A. Parish Unit 8 because this
unit has a scrubber installed that maintains an SO2 emission
rate four to five times lower than the emission rate of the other coal-
fired units at the facility that are uncontrolled and are participating
in the Texas SO2 Trading Program (Parish Units 5, 6, and
7).\122\ Therefore, we expect that any shifting of generation from the
participating units at the Parish facility to Parish Unit 8 would not
present a problem, and instead would result in a decrease in overall
emissions from the source. Similarly, with regard to Oak Grove Units 1
and 2, and Sandy Creek Unit 1, these are relatively newer coal fired
units that began operation in late 2009 or after, are not BART eligible
and have scrubbers installed that maintain SO2 emission
rates much lower than the uncontrolled units included in the
program.\123\ Thus, we did not include Oak Grove Units 1 and 2, and
Sandy Creek Unit 1 for participation in the Texas SO2
Trading Program. Although the Twin Oaks facility was identified as
having a Q/d greater than 10, we did not include it in the trading
program based on its relatively low potential to impact visibility at
Class I areas. For instance, the facility does not include any BART-
eligible EGUs; the Q/d for this facility is 14.2, which is
significantly lower than that of other Texas facilities on our list
with a Q/d value over 10; \124\ and the estimated Q/d for each
individual unit (Units 1 and 2) is less than 10. Considering the above,
we do not consider the potential visibility impacts from Twin Oaks
Units 1 and 2 to be significant relative to the other coal-fired EGUs
in Texas with Q/d's much greater than 10 and therefore did not include
them in the program.\125\ We also note that annual SO2
emissions from Twin Oaks Units 1 and 2 in 2017-2019, which are the
three most recent years for which annual emissions data are available,
have been well below the 2009 emissions level of 4,707 tons of
SO2.\126\ Thus, we believe the results of the Q/d analysis
as well as our consideration of unique circumstances specific to each
unit are sufficient information to justify excluding certain units from
the Texas SO2 Trading Program that were included under
CSAPR, without necessitating a quantitative examination of the
visibility impact of excluding these units.
---------------------------------------------------------------------------

    \120\ 83 FR 43597.
    \121\ See 84 FR at 61853, footnote 20.
    \122\ 83 FR 43596.
    \123\ Id. 43601.
    \124\ Id. FR 43596-97. As discussed in our August 2018 proposal,
after identifying the BART-eligible sources included in the Texas
SO2 Trading Program, we evaluated additional sources for
potential inclusion in the trading program based on their potential
to impact visibility at Class I areas. We used a Q/d value of 10 as
a threshold for identification of facilities that may impact
visibility at Class I areas and could be included in the trading
program. We identified a total of 17 facilities in Texas with Q/d
values greater than 10, some of which are not BART-eligible and had
not already been identified for inclusion in the program. The Q/d
values for these 17 facilities range from 14.2 (for Twin Oaks) to
425.4 (for Monticello).
    \125\ Id. FR 43597.
    \126\ Annual SO2 emissions from Twin Oaks Units 1 and
2 were 2,472 tons in 2017; 2,523 tons in 2018; and 2,408 tons in
2019. See excel spreadsheet ``Twin Oaks- SO2 annual
emissions_2009 and 2017-2019.xlsx,'' available in the docket for
this action.
---------------------------------------------------------------------------

    With regard to the comment contending that we arbitrarily selected
2009 as the emissions year in our Q/d analysis, we note that to
identify facilities that may impact visibility at Class I areas in our
October 2017 final rule, we relied on an already existing Q/d analysis
that we prepared as part of the December 2014 proposal to address
Texas' reasonable progress requirements, and which was based on 2009
emissions.\127\ In that proposed action, we also reviewed 2010 and 2011
emission data that became available as we were developing that proposed
rule. We determined that the only EGU facility that was above the Q/d
for 2010 and 2011 compared to the 2009 analysis was the Oak Grove
facility, which came online in late 2009. As we discuss above, this is
a new facility that is equipped with scrubbers and we determined it was
not necessary to include them in the Trading Program. The Regional Haze
Rule does not require us to select a range of years for the emissions
data for our Q/d analysis

nor does it identify a particular year that must be used for the
emissions data. We have the discretion to select the emissions data
year as long as we provide a reasonable justification for our
selection, as we have done in this case.\128\
---------------------------------------------------------------------------

    \127\ See the TX RH FIP TSD that accompanied our December 2014
proposal to address reasonable progress requirements for Texas (79
FR 74818 (Dec 16, 2014)), and the Excel file
``2009statesum_Q_D.xlsx.'' These files are available in Docket ID
EPA-R06-OAR-2014-0754, see Document ID EPA-R06-OAR-2014-0754-0007
and EPA-R06-OAR-2014-0754-0007-05.
    \128\ 83 FR 43597.
---------------------------------------------------------------------------

    With regard to the comment regarding the opt-in provision, we
appreciate the commenter's input on whether that provision differs from
the provisions of the CSAPR SO2 program in a manner that
could decrease the relative overall stringency of the Texas
SO2 Trading Program. In our November 2019 supplemental
proposal, we proposed to modify the regulations to terminate the opt-in
provision, and we are adopting that proposed modification in this final
action.
    Comment: One commenter asserted that the Texas SO2
Trading Program is arbitrary, capricious, and unlawful because EPA did
not follow its own policies and regulations in the ``clear weight of
evidence'' approach taken under Sec.  51.308(e)(2)(i)(E) to demonstrate
that the trading program achieves greater reasonable progress than
BART. The commenter pointed to EPA's action on the Utah Regional Haze
SIP, in which EPA stated that pursuant to the Regional Haze Rule
requirements for a BART alternative, the clear weight-of-evidence test
requires three steps that can generally be summarized as follows: (1)
Use information and data that can inform the decision . . . ; (2)
Evaluate the information and recognize the relative strengths and
weaknesses of the metrics used, including assigning weights to each
piece of information that indicate the degree to which it supports a
finding that the alternative program will achieve greater visibility
benefits; and (3) Collectively consider the weights assigned to the
individual pieces of information and consider the total weight of all
the information to determine whether the proposed BART alternative will
clearly provide for greater reasonable progress than BART at the
impacted Class I areas. The commenter asserted that in contrast to our
evaluation of Utah's BART alternative, EPA did not follow the three-
step process for making a clear weight of the evidence demonstration
under 40 CFR 51.308(e)(2) to demonstrate that the Texas SO2
Trading Program achieves greater reasonable progress than BART. The
commenter asserted that EPA should have identified, weighed and
carefully considered certain information the commenter considers to be
relevant and easily available to inform EPA's clear weight of evidence
approach and decision regarding the Texas SO2 Trading
Program, including EPA's January 2017 Texas BART proposal, recent
emissions data, presumptive BART emission rates and emission
reductions, the weaknesses of the outdated CSAPR evaluations,
significant differences between the Texas SO2 Trading
Program and CSAPR, and EPA's own previous evaluation when withdrawing
Texas from CSAPR showing greater emission reductions under BART.
    The commenter further asserted that the clear weight of evidence
demonstrates that the trading program will not make greater reasonable
progress than BART based on EPA's prior determination that CSAPR would
achieve lower emissions reductions than source-specific BART for Texas
EGUs. The commenter cited to three prior rulemakings in which,
according to the commenter, the EPA has concluded that CSAPR would
achieve less reasonable progress than source-specific BART in Texas:
(1) The January 2017 BART proposal; (2) the original CSAPR Better-than-
BART rulemaking; and (3) the 2017 rulemaking to remove Texas from
CSAPR's SO2 trading program. The commenter asserted that
since the Texas SO2 Trading Program is intended to mimic the
effect of CSAPR, and CSAPR would achieve less reasonable progress than
BART in Texas, it follows that the Texas SO2 Trading Program
would also achieve less reasonable progress than BART, and therefore
would not satisfy the requirements of the Regional Haze Rule at 40 CFR
51.308(e)(2), (e)(2)(i)(E), and (e)(3).
    Response: EPA disagrees that we are applying a different standard
for ``clear weight of evidence'' than we have in other cases. The
specific circumstances of Texas as compared to Utah are readily
distinguishable. Specifically, the Better-than-BART demonstration for
our Texas SO2 Trading Program relies on the quantitative
modeling, analyses and demonstrations supporting our June 2012 ``CSAPR
Better-than-BART'' determination and September 2017 ``CSAPR Better-
than-BART affirmation finding'' (as recently reaffirmed by our denial
of a petition for reconsideration on the latter). This analysis follows
the two-part quantitative test of Sec.  51.308(e)(3), and in our weight
of evidence approach, we rely on that technical analysis, as
supplemented by additional evidence that the Texas intrastate trading
program achieves at least the same amount of emission reductions as
were projected for Texas in the CSAPR analysis (including accounting
for potential shifting in emissions to CSAPR states with the removal of
Texas from the program). The commenter attempts to elevate EPA's
general guidance on conducting a clear weight of evidence analysis, set
forth in a separate regional action, into a mandatory test that states
or the agency must always adhere to. However, the evidence-based
inquiry called for under Sec.  51.308(e)(2)(i)(E) is inherently fact-
specific, and EPA has set forth why information in this record supports
its findings. The State of Utah, in a far different context, had
attempted to show by a series of metrics (many of which were novel and
unique to that SIP submittal) that a BART alternative achieved greater
reasonable progress than BART, but the state failed to explain how it
weighed these metrics, and EPA found that one of the most important
metrics in that instance (visibility impact on the 98th percentile day)
did not actually support the alternative.\129\ Here, rather than
setting out a list of factors to evaluate, EPA is primarily relying on
the CSAPR Better-than-BART analysis under the quantitative test of
Sec.  51.308(e)(3) (in addition to showing that other Sec.
51.308(e)(2) requirements are met), as explained elsewhere in the
record.
---------------------------------------------------------------------------

    \129\ 81 FR at 43898.
---------------------------------------------------------------------------

    Comment: One commenter asserted that the Texas SO2
Trading Program is not an adequate SO2 BART alternative
because it is not a cap and trade program that might actually reduce
SO2 emissions beyond the overall cap. Further, the commenter
argues that the cap set by EPA in the trading program is too high and
actually allows the participating units to increase their
SO2 emissions. The commenter stated that in upholding EPA's
authority to select an alternative to source-specific BART, the D.C.
Circuit has held that the overriding requirement for each regional haze
plan is that it make reasonable progress toward eliminating haze
pollution. The commenter asserted that the Texas SO2 Trading
Program does not satisfy this overriding requirement since, according
to the commenter, it would not result in any progress because it does
not require any emissions reductions relative to actual emissions from
covered sources in 2015, 2016, and 2017. The commenter argued that the
Texas SO2 Trading Program actually authorizes covered
sources to increase emissions relative to actual emissions in 2015,
2016, and 2017, and that it therefore does not achieve greater
reasonable progress than source-specific BART and is not an appropriate
BART alternative. The commenter also claimed that by

authorizing even higher emissions than seen in 2015-2017, the Texas
SO2 Trading Program would likely further erode whatever
gains were made post-2014. The commenter asserted that the Texas
SO2 Trading Program authorizes sources to emit as much as
293,104 SO2 tons considering that the Supplemental Allowance
Pool may grow over time, which would equate to a 47,234 ton increase
over 2017 emissions, and a 74,813 ton increase over 2016 emissions. The
commenter argued that even if the potential growth in the Supplemental
Allowance Pool (from an initial 10,000 tons to 54,711 tons) is ignored,
and one uses 248,393 tons as the total number of allowances, the Texas
SO2 Trading Program would still authorize an increase in
emissions over actual emissions in 2015, 2016, and 2017. The commenter
asserted that the Texas SO2 Trading Program would thus fail
to require greater reasonable progress than BART and would actually
authorize greater pollution than the status quo. Furthermore, the
commenter asserted that source-specific BART is the only option EPA has
proposed that is consistent with statutory requirements and goals.
According to the commenter, the January 2017 source-specific BART
proposal, or even presumptive BART, would reduce emissions and improve
visibility far more than the Texas SO2 Trading Program, and
should be finalized in place of the trading program.
    Additionally, the commenter argued that in EPA's determination that
the Texas SO2 Trading Program will decrease SO2
emissions relative to 2014 emission levels, EPA's selection of 2014 as
the baseline year for determining whether the Texas SO2
Trading Program would reduce emissions and improve visibility was
arbitrary. The commenter asserted that EPA should have instead selected
2017 as the baseline year because that is the most recent year for
which annual emissions data is available and in which Texas sources
were not part of CSAPR for SO2. The commenter claimed that
the Texas SO2 Trading Program will result in no progress
toward the goal of eliminating haze pollution and will therefore be in
direct violation of the Clean Air Act's visibility mandate.
    Response: We do not agree that addressing Texas' SO2
BART requirements through a source-specific BART FIP is the only option
that meets the regulatory and statutory requirements. Our October 2017
final rule fulfilled our mandatory duty to address the BART
requirements for Texas EGUs through the promulgation of a FIP
containing a BART alternative in the form of an intrastate trading
program. The Texas SO2 Trading Program, as amended in this
final action through the addition of the 255,083-ton assurance level
and other amendments discussed in section III.A.1 of this final action,
will result in annual emissions from the covered EGUs and other EGUs in
Texas that are lower than what was required under Texas participation
in CSAPR's SO2 trading program. Thus, the clear weight of
evidence is that, overall, the Texas trading program (considered in the
larger context of CSAPR) will provide greater reasonable progress than
BART at the covered sources and satisfies the requirements for a BART
alternative under 40 CFR 51.308(e)(2)(i)(E).
    The comment contending that we arbitrarily elected not to use 2017
as the baseline emissions year for comparing the Texas SO2
Trading Program to BART is incorrect. We considered 2014 as the
appropriate most recent year for comparing the Texas SO2
Trading Program to BART for the purposes of meeting the requirement of
40 CFR 51.308(e)(2)(i)(D) given that Texas sources were subject to the
CSAPR SO2 trading program in 2015 and 2016 but are no longer
subject to that program.\130\ This analysis was included in our October
2017 final rule, at a time when 2017 emissions data were not yet
available. The Regional Haze Rule does not require us to select 2017 or
any specific year as the baseline year for our assessment under 40 CFR
51.308(e)(2)(i)(D) of emission reductions achievable by the trading
program, and commenter establishes no basis why we should have been
required to update this analysis in our August 2018 proposal to affirm
the rule. Our BART alternative analysis for Texas relied on 2014 data
to be consistent with the CSAPR Better-than-BART analysis given that we
are relying on the demonstration in the 2012 CSAPR Better-than-BART
rule (as affirmed in 2017) to show that the clear weight of evidence
demonstrates that the Texas SO2 Trading Program, which is
modeled on the CSAPR trading programs, will provide for greater
reasonable progress than BART in Texas as required under 40 CFR
51.308(e)(2)(i)(E).\131\ We have provided a reasonable explanation for
our selection of 2014 as the historical baseline year for the purposes
of meeting the requirement of 40 CFR 51.308(e)(2)(i)(D).
---------------------------------------------------------------------------

    \130\ 83 FR 43598.
    \131\ Note that the year 2014 is not relevant to the question of
whether emissions achieved by the program are surplus to the
baseline date for purposes of 40 CFR 51.308(e)(2)(iv). For purposes
of meeting the requirements of 40 CFR 51.308(e)(2)(iv), the baseline
date is 2000-2004.
---------------------------------------------------------------------------

    The commenter's suggestion that the Texas SO2 Trading
Program should be structured to achieve additional emission reductions
beyond the cap is effectively similar to other comments advocating for
a lower cap or a more stringent program generally. As discussed
elsewhere in this document, we continue to believe that the Texas
SO2 Trading Program is sufficiently stringent to meet the
requirements to qualify as a BART alternative in the context of the
2012 CSAPR Better-than-BART rule and the 2017 CSAPR Better-than-BART
affirmation finding. The comment contending that the Texas
SO2 Trading Program authorizes sources to increase emissions
relative to actual emissions in 2015, 2016, and 2017, and authorizes
greater pollution than the status quo mischaracterizes the Texas
SO2 Trading Program and reflects a misunderstanding of its
purpose. First, we note that the Texas SO2 Trading Program
will achieve an average reduction of at least 54,213 tons per year over
the 2014 emissions, which is the difference between the aggregate 2014
SO2 emissions of the covered Texas EGUs (309,296 tons per
year) \132\ and the assurance level of 255,083 tons we are finalizing
in this action. The assurance level represents the highest annual
SO2 emissions anticipated from units subject to the Texas
SO2 Trading Program in light of the three-for-one penalty
surrender ratio imposed on emissions exceeding that level, and is
therefore a conservatively high figure to compare against 2014 actual
emissions levels. Second, and notwithstanding our position that we
appropriately selected 2014 as the baseline year for the purpose of
this analysis, we note that even if we had selected 2017 as the
baseline year, we disagree that the Texas SO2 Trading
Program would authorize greater pollution than the status quo given
that the trading program now contains an assurance level limiting
SO2 emissions from Texas EGUs participating in the trading
program where no prior SO2 emission limits under the
regional haze program existed for these sources. Therefore, we disagree
that the Texas SO2 Trading Program authorizes greater
pollution than the status quo even under the assumption of 2017 as the
baseline year for comparison against the Texas SO2 Trading
Program as the status quo ``authorizes'' much higher emissions (due to
there being no enforceable program at all and the only limitations
being the facilities' current permit limits), even if actual emissions

happened to be below that level. As discussed in section III.A.2 of
this final action, we note that the Texas SO2 Trading
Program with the added assurance level we are finalizing in this
action, also achieves significantly lower emissions relative to the
year 2002.\133\ These emission reductions that are secured by the
Trading Program contribute to improvements in visibility from the
baseline period for the first planning period and are permanent and
enforceable as part of the long-term strategy for the State of Texas.
---------------------------------------------------------------------------

    \132\ 84 FR at 61854.
    \133\ The Regional Haze Rule provides that the baseline period
for the first planning period is 2000-2004. See 40 CFR
51.308(d)(2)(i).
---------------------------------------------------------------------------

    Further, the purpose of the program is not to achieve some
particular quantum, much less a maximum quantum, of emission reductions
as compared to some reference point for ``current'' emission levels. In
fact, whether the Texas SO2 Trading Program allows for a
potential increase in emissions from recent or current emission levels
is not the relevant question under the BART alternative provisions of
the Regional Haze Rule. In order to satisfy the BART alternative test
of 40 CFR 51.308(e)(2)(i)(E), the alternative must, on the clear weight
of evidence, achieve greater reasonable progress in visibility
improvements than would be achieved through the installation and
operation of BART at the covered sources. This test calls for a
comparison in stringency between two regulatory regimes, BART and the
BART alternative. The Texas SO2 Trading Program is modeled
on and set at a stringency level comparable to CSAPR in Texas, such
that the CSAPR Better-than-BART analysis may be relied upon in
determining the adequacy of this program. As discussed in section
III.A.2, we find that we have satisfied the BART alternative test of 40
CFR 51.308(e)(2)(i)(E). Whether actual emissions may increase or
decrease from some particular historical level under the program is
immaterial so long as emissions remain below the level requisite to
make the ``greater reasonable progress'' showing.
    To the extent the commenter is asserting that certain aspects of
the program, such as allocations to retired units, the availability of
banking, and allocations from the Supplemental Allowance Pool, pose a
risk that the program will fail to achieve the emission levels assumed
in our analysis, this theoretical concern is addressed by amendments to
the program finalized in this action. To address concerns regarding
potentially higher SO2 emissions in individual years from
Texas EGUs participating in the trading program, on November 1, 2019,
we signed a supplemental notice of proposed rulemaking that proposed to
add assurance provisions to the Texas SO2 Trading Program.
Under the assurance provisions, if the total emissions of the sources
in the program in any year exceed the annual program budget by more
than a variability limit of 16,688 tons, the emissions over that
``assurance level'' will trigger a requirement for some sources to
surrender three allowances for each ton of emissions, providing a
strong disincentive against emissions exceeding the assurance level. We
are finalizing that supplemental proposal in this action.\134\ As we
explained in the supplemental proposal, the assurance level effectively
moots any concerns regarding annual emission performance under the
program by establishing a cap implemented via the penalty surrender
ratio. This is because when a mass-based trading program includes a
``cap'' on overall annual emissions, as the Texas SO2
Trading Program now does with the addition of the assurance provisions,
that overall ``cap'' on emissions set by the program (here, the
assurance level) effectively determines the stringency of the program
in each year. With the addition of an assurance level, the potential
risk of an undue relaxation of the annual stringency in the program is
minimized given that sources will remain strongly incentivized to keep
annual emissions below the level at which the three-for-one surrender
penalty is imposed. Thus, how allowances are allocated or banked within
that cap does not affect the overall stringency of the program.\135\
---------------------------------------------------------------------------

    \134\ The final ``assurance level'' is 255,083 tons, which is
the sum of the revised annual program budget of 238,395 tons plus
the variability limit of 16,688 tons. As discussed in section
III.A.1 of the preamble for this action, for consistency with the
assurance provisions, EPA is also making revisions to the
Supplemental Allowance Pool provisions that will limit the combined
total quantity of allowances issued in any year from the program
budget and the Supplemental Allowance Pool to this same level of
255,083 tons.
    \135\ See 84 FR 61854.
---------------------------------------------------------------------------

    Comment: The commenter asserted that even a ``successful'' cap and
trade program cannot avoid localized impacts to particular Class I
Areas, much less to local communities most impacted by large pollution
sources, and that the Trading Program is therefore not an adequate BART
alternative.
    Response: The Regional Haze Rule does not require that a BART
alternative achieve greater visibility improvements than BART at each
particular Class I area, and only requires that a BART alternative does
not result in declines in visibility compared to the baseline in any
class I area. EPA's decision to authorize alternative measures,
including emissions trading programs, subject to those requirements, in
the original 1999 Regional Haze Rule is beyond the scope of this
action. Further, the test EPA devised under 51.308(e)(3) for evaluating
whether a BART alternative makes greater reasonable progress calls for
an evaluation of whether there could be unacceptable localized
visibility impacts under a BART alternative. In particular, the
analysis asks whether visibility will decline in any class I area under
the BART alternative as compared with the baseline scenario. This
evaluation was done as part of the 2012 CSAPR Better-than-BART analytic
demonstration, which was relied upon in developing the Texas
SO2 Trading Program. That analysis showed no decline in
visibility in any Class I area compared to the baseline emissions
scenario.

B. PM BART

    Comment: We received one comment raising several objections to
EPA's proposal to affirm approval of Texas' finding that no PM BART
controls are necessary for EGUs based on Texas' pollutant-specific
screening analysis for PM. The commenter asserted that the Regional
Haze Rule and the BART Guidelines require that the BART screening
analysis evaluate the impacts of all pollutants together, not just PM,
and that a source-specific, five-factor analysis of PM BART must then
be conducted for each EGU found to be subject to BART. The commenter
asserted that Texas' pollutant-specific screening analysis did not meet
these requirements and that EPA's proposed approval of Texas' finding
that its sources are exempt from PM BART is thus inappropriate. The
commenter also argued that EPA's proposal to affirm approval of Texas'
pollutant-specific screening analysis for PM BART is arbitrary and
capricious for several reasons, including the following: (1) Approval
of Texas' screening approach is contrary to the plain language of the
Clean Air Act; (2) Texas' screening approach is directly contrary to
the agency's regional haze regulations and mandatory BART guidelines;
(3) EPA's approval of a pollutant-specific screening approach
arbitrarily departs from the agency's past practice; and (4) EPA failed
to provide a rational explanation for proposing to approve Texas'
application of a pollutant-specific screening analysis in this case.
    Specifically, the commenter claimed that approval of Texas'
screening approach is contrary to the plain language of the Clean Air
Act because

the commenter believes this effectively exempts sources from installing
PM BART controls without going through the statutory exemption process
Congress prescribed. The commenter asserted that Congress specifically
provided that sources could be exempted from the BART requirements only
if the Administrator determines that a source does not or will not, by
itself or in combination with other sources, emit any air pollutant
which may reasonably be anticipated to cause or contribute to a
significant impairment of visibility in any Class I area, and that the
FLMs must concur with any proposed exemption. The commenter argued that
EPA has not demonstrated that any of the BART-eligible Texas EGUs meet
the statutory requirements for an exemption and EPA has not obtained
the concurrence of federal land managers for exempting sources for PM
BART.
    The commenter asserted that Texas' screening approach is directly
contrary to the agency's regional haze regulations and mandatory BART
guidelines. The commenter asserted that the Regional Haze Rule and BART
guidelines do not provide for any exemptions from a five-factor BART
analysis for specific pollutant, with the exception of a de minimis
exemption under Sec.  308(e)(1)(ii)(C) for sources that emit less than
15 tons per year of particulate matter. The commenter argued that
neither EPA nor Texas attempted to demonstrate that this de minimis
exemption applies to any of Texas' EGUs.
    The commenter also argued that EPA's approval of a pollutant-
specific screening approach arbitrarily departs from the agency's past
practice. Specifically, the commenter claimed that EPA has rejected
similar pollutant-specific approaches to BART determinations in past
regional haze actions. For instance, the commenter asserted that in a
prior regional haze action where EPA partially disapproved the Arizona
Regional Haze SIP (78 FR 46142 (July 30, 2013)), EPA stated that under
the Regional Haze Rule, the determination of whether a source causes or
contributes to visibility impairment is not made on a pollutant-by-
pollutant basis and that once a source is determined to be subject to
BART, the Regional Haze Rule allows for the exemption of specific
pollutants from a BART analysis only if they are below specified de
minimis levels.
    The commenter also raised an objection to EPA's reliance on a 2006
guidance document in proposing to approve Texas' application of a
pollutant-specific screening analysis for PM BART. The commenter argued
that the EPA's 2006 guidance document on which EPA based its proposed
approval of Texas' pollutant-specific screening analysis was never
subject to notice and comment and is therefore not binding.
Furthermore, the commenter asserted that EPA did not explain how the
2006 guidance document is applicable in this case given that the
guidance document does not contain an analysis or rationale and does
not cite or incorporate any technical justification for allowing the
use of a pollutant-specific screening approach. The commenter also
argued that the guidance document contemplates the use of a pollutant-
specific screening analysis in situations where a state is subject to
both SO2 and NOX emission reductions under the
Clean Air Interstate Rule, not CSAPR or some other trading program as
in this case. The commenter also argued that reliance on the 2006
guidance document is not appropriate in this case because Texas
participates in CSAPR for ozone season NOX and is therefore
not subject to annual NOX emission limits.
    The commenter also asserted that in its screening analysis, Texas
did not provide a rationale or justification for its selection of 0.5
dv as the threshold for contribution to visibility impairment. The
commenter argued that EPA's BART Guidelines do not authorize states or
EPA automatically to use a 0.5 dv contribution threshold, but instead
provide that any threshold states use for determining whether a source
contributes to visibility impairment should not be higher than 0.5 dv.
The commenter claimed that given the number of Texas sources and the
magnitude of their impact at affected Class I areas, a contribution
threshold lower than 0.5 dv may be appropriate.
    Response: We are affirming our approval of Texas' pollutant-
specific PM screening analysis and determination that PM BART emission
limits are not required for any Texas EGUs as in accordance with EPA
guidance and the Regional Haze Rule. As we explained in our August 27,
2018 affirmation proposal, in a 2006 EPA memorandum titled ``Regional
Haze Regulations and Guidelines for Best Available Retrofit Technology
(BART) Determinations,'' EPA stated that pollutant-specific screening
can be appropriate where a state is relying on a trading program as a
BART alternative to address both NOX and SO2
BART.\136\ As discussed in the 2006 guidance, for EGU sources that are
addressing the NOX and SO2 BART requirements by
participation in a trading program as a BART alternative, such as CAIR,
the state must still determine whether its BART-eligible EGUs are
subject to review under BART for PM. In this situation, as this is the
only determination that remains and because the task of predicting the
impacts of PM on visibility is a relatively straight-forward exercise,
unlike predicting the impacts of the non-linear reacting pollutants
SO2 and NOX, a pollutant-specific basis to model
only the impact of PM emissions on visibility is recommended to
determine whether a source is subject to BART for PM. We note that the
2006 memorandum is consistent with the BART Guidelines, which provide
that a state ``may choose to perform an initial examination to
determine whether a particular BART-eligible source or group of sources
causes or contributes to visibility impairment in nearby Class I areas.
If your analysis, or information submitted by the sources, shows that
an individual source or group of sources (or certain pollutants from
those sources) is not reasonably anticipated to cause or contribute to
any visibility impairment in a Class I area, then you do not need to
make BART determinations for that source or group of sources (or for
certain pollutants from those sources).'' \137\ In sum, the 2006 EPA
memorandum is consistent with the BART Guidelines and clearly states
that a pollutant-specific analysis for PM emissions is an appropriate
approach in certain carefully circumscribed circumstances, such as are
present here.
---------------------------------------------------------------------------

    \136\ See discussion in Memorandum from Joseph Paisie to Kay
Prince, ``Regional Haze Regulations and Guidelines for Best
Available Retrofit Technology (BART) Determinations,'' July 19,
2006. While the memorandum specifies that pollutant-specific
screening is appropriate for states relying on CAIR, it is
reasonable to infer that other trading programs, such as CSAPR and
the Texas SO2 Trading Program, also qualify to use this
approach.
    \137\ 40 CFR part 51 Appendix Y, Section III.
---------------------------------------------------------------------------

    While the commenter is correct that in our January 4, 2017 BART FIP
proposal,\138\ we initially proposed to disapprove Texas' technical
evaluation and determination in the 2009 Regional Haze SIP that PM BART
emission limits are not required for any of Texas' EGUs, this was
because Texas was not participating in CSAPR for SO2 or in
any other SO2 emissions trading program or BART alternative
at the time and thus did not meet the criteria described in our 2006
guidance. In our October 2017 final action, we addressed the
SO2 BART requirements for Texas EGUs under a BART
alternative consisting of an intrastate trading program. Given that
Texas is relying on participation in the CSAPR ozone season trading
program for NOX to

satisfy NOX BART for Texas EGUs and is now also subject to a
BART alternative consisting of an SO2 intrastate trading
program to satisfy the SO2 BART requirements for Texas EGUs,
Texas is relying on a trading program as a BART alternative to address
both NOX and SO2 BART. Thus, pollutant-specific
screening for PM as performed by Texas in its 2009 SIP submittal was
appropriate, consistent with the BART Guidelines \139\ and the 2006 EPA
memorandum.\140\
---------------------------------------------------------------------------

    \138\ 82 FR 912.
    \139\ 40 CFR part 51 Appendix Y, Section III.
    \140\ See Memorandum from Joseph Paisie to Kay Prince,
``Regional Haze Regulations and Guidelines for Best Available
Retrofit Technology (BART) Determinations,'' July 19, 2006.
---------------------------------------------------------------------------

    We disagree with the commenter's assertion that EPA's approval of a
pollutant-specific screening approach arbitrarily departs from the
agency's past practice. EPA has previously determined that this
approach is appropriate for EGUs where a State relied on CAIR or CSAPR
to satisfy the BART requirements for SO2 and NOX
and has approved SIPs where the State required its BART-eligible EGUs
to only evaluate PM emissions for determining whether they are subject
to BART, and, if applicable, for performing a BART control assessment.
We also note that in these analyses EPA approved a threshold of 0.5 dv
for determining which sources were subject to BART.\141\
---------------------------------------------------------------------------

    \141\ See for example the approval of Regional haze SIPs for
Georgia (77 FR 11452 for proposed rule and 77 FR 38501 for final
rule), South Carolina (77 FR 11894 for proposed rule and 77 FR 38509
for final rule), and Kentucky (76 FR 78194 for proposed rule and 77
FR 19098 for final rule).
---------------------------------------------------------------------------

    With regard to the commenter's assertion that our approval of
Texas' selection of 0.5 dv as the threshold for visibility impairment
for PM was improper, as an initial matter, as explained in our August
2018 proposal to affirm the October 2017 final rule promulgating the
Texas SO2 Trading Program, we did not reopen the subject-to-
BART determinations for sources not covered by the trading program,
which screened out of the BART program based on consideration of all
visibility pollutants.\142\ With respect to the BART sources included
in the trading program, EPA requested comment on its PM-specific
screening analysis.\143\ EPA's basis for approving the 0.5 dv value for
screening purposes was that EPA's BART Guidelines allow states
conducting source-by-source BART determinations to exempt sources with
visibility impacts as high as 0.5 dv.144 145 Further, the
BART Guidelines provide that in setting a contribution threshold,
states should ``consider the number of emissions sources affecting the
Class I areas at issue and the magnitude of the individual sources'
impacts.'' States have the discretion within the Clean Air Act,
Regional Haze Rule, and BART Guidelines to set an appropriate
contribution threshold and are free to use a threshold lower than 0.5
dv if they conclude that the location of a large number of BART-
eligible sources in proximity of a Class I area justifies this
approach. Texas did not determine in its 2009 Regional Haze SIP that
there were circumstances in this case to justify the selection of a
lower threshold. EPA continues to find that Texas was within its
discretion to select a threshold of 0.5 dv in its BART screening
analysis. In light of the above-referenced 2006 memorandum recognizing
the availability of a pollutant-specific approach to BART where BART
sources are already separately controlled for SO2 and
NOX by one or more BART alternative trading programs, we are
finalizing our proposed affirmation that no BART-eligible source in
Texas is subject to BART for PM on a pollutant-specific basis. In
finalizing an affirmation of our approval of Texas' determinations
regarding PM BART, we offer one additional note. We originally proposed
to approve Texas' screening approach in 2014,\146\ and our October 2017
final action again relied on our technical evaluation in that proposal
for the basis of our approval. We therefore incorporate by reference
the technical evaluation regarding this issue from our 2014 proposal
into the record for this action.\147\
---------------------------------------------------------------------------

    \142\ 83 FR 43598 n. 80.
    \143\ Id. 43592-93.
    \144\ 70 FR 39104, 39161 (July 6, 2005) and 40 CFR part 51
Appendix Y, Section III.A.1.
    \145\ 82 FR at 48346 and 79 FR at 74848.
    \146\ See 79 FR 74817, 74848 (Dec. 16, 2014).
    \147\ 79 FR 74817, 74848.
---------------------------------------------------------------------------

    Comment: We received a comment asserting that the 2006 intra-agency
memorandum on which EPA relies to propose approval of Texas' pollutant-
specific screening approach is inconsistent with the Clean Air Act and
the Regional Haze Rule, and EPA's interpretation of its regulations is
therefore not entitled to deference. Bowles v. Seminole Rock & Sand
Co., 325 U.S. 410, 414 (1945) (agency interpretation of its regulation
is not controlling where ``it is plainly erroneous or inconsistent with
the regulation''); see also Auer v. Robbins, 519 U.S. 452, 461 (1997)
(same). The commenter further asserted that courts have repeatedly
criticized agency use of guidance documents in the form of interpretive
rules and policy statements to reinterpret regulations, recognizing the
potential problem that ``[l]aw is made, without notice and comment,
without public participation, and without publication in the Federal
Register or the Code of Federal Regulations.'' Decker v. Northwest
Envtl. Def. Ctr., 133 S. Ct. 1326, 1341 (2013); Perez v. Mortgage
Bankers Ass'n, 135 S. Ct. 1199, 1213-14 (Mar. 9, 2015); see also
Appalachian Power Co. v. EPA, 208 F.3d 1015, 1020 (D.C. Cir. 2000)
(criticizing agency use of guidance documents in the form of
interpretive rules and policy statements, recognizing the potential
problem that ``[l]aw is made, without notice and comment, without
public participation, and without publication in the Federal Register
or the Code of Federal Regulations.'').
    Response: EPA has the authority to develop and implement policies
and guidance. EPA sometimes issues policy or guidance to encourage
compliance with environmental requirements. Policy documents may
represent EPA's official interpretation or view of specific issues.
However, ultimately, EPA's actions with regards to guidance documents
must be consistent with applicable statutory and regulatory
requirements. The EPA disagrees that its reference to the 2006 guidance
is inconsistent with the CAA or constitutes a legislative or
interpretive rule, and we have reasonably relied, in part, on this
guidance document in our approval of Texas' determination that no BART-
eligible sources in Texas are subject to BART for PM on a pollutant-
specific basis. As explained in response to similar comments above,
application of pollutant-specific screening for PM is appropriate in
Texas and is not inconsistent or at odds with either the CAA statute or
applicable EPA regulations, for the reasons explained in response to
those comments. We, therefore, disagree that our interpretation of the
2006 memorandum here is inconsistent with the Clean Air Act regarding a
pollutant-specific screening approach for PM BART.

C. Appropriateness of the Texas SO2 Trading Program vs. Source-Specific
BART FIP

    Comment: One commenter raised objections to EPA's finalization of
the October 17, 2017 final rule promulgating the Texas SO2
Trading Program, asserting that EPA provided no rational basis for
finalizing a FIP promulgating an intrastate trading program in place of
the source-specific BART FIP proposal that was proposed by EPA in
January 2017. The commenter asserted that the January 2017 BART FIP
proposal was supported by detailed, source-specific analyses of the
cost of

SO2 controls, the level of control achievable by different
technologies, estimated emissions reductions, and projected visibility
improvement from operation of such controls, and that this
administrative record demonstrated that the 2017 BART FIP proposal
meets the requirements of the Regional Haze Rule and CAA and should
have been finalized by EPA.
    Response: While EPA proposed source-specific BART emission limits
in the January 2017 proposal, under the notice and comment rulemaking
process, EPA may decline to finalize a proposed rule or may finalize a
rule with changes from proposal based on consideration of additional
information received during the comment period. Additionally, EPA may
also propose a rule and rationale that differs from its original
proposal and does not have an obligation to finalize the initial
proposed rule as is the case here. We also note that the Regional Haze
Rule does not require source-specific BART determinations, as the
regulations at 40 CFR 51.308(e)(2)-(5) allow states, or EPA if
promulgating a FIP, to adopt a BART alternative in place of source-
specific BART provided that all applicable regulatory requirements
related to the BART alternative are satisfied. EPA's obligations are to
promulgate a final rule that meets the requirements of the CAA and the
Regional Haze Rule, consider and respond to all relevant comments to
the final rule, and provide a record of decision-making for its action
that is not arbitrary and capricious. In this case, informed by
comments we received during the public comment period for the January
2017 proposal from the Texas Commission on Environmental Quality
(TCEQ), the Public Utility Commission of Texas (PUC), Luminant, and
American Electric Power (AEP), urging us to consider as a BART
alternative the concept of emission caps using CSAPR allocations,\148\
and based on our independent determination that a BART alternative
approach under 40 CFR 51.308(e)(2) would meet all statutory and
regulatory requirements and thus be viable for Texas, we did not
finalize the source-specific BART emission limits we had proposed and
instead we addressed the SO2 BART requirement for Texas EGUs
under a BART alternative consisting of an intrastate trading program in
our October 2017 final rule. Having made the determination (in part
through reliance on the analysis of CSAPR as a BART alternative as
explained elsewhere in the record) that the BART-alternative program
satisfies 40 CFR 51.308(e)(2) under the clear weight of evidence test
of 40 CFR 51.308(e)(2)(i)(E), EPA need not further explain or justify
the program based on a comparison of emission reductions, costs, or
visibility improvements that may have been potentially achieved had EPA
finalized the source-specific controls we proposed in January 2017. The
statute and applicable regulations do not mandate that states, or EPA
when it is promulgating a FIP, reach a particular conclusion or outcome
regarding cost-effectiveness or emission reductions when applying the
five-factor BART analysis, or in designing a BART-alternative program
under 40 CFR 51.308(e).
---------------------------------------------------------------------------

    \148\ 82 FR 48324 at 48327.
---------------------------------------------------------------------------

    Comment: We received one comment asserting that EPA never
identified any errors in the January 2017 BART FIP proposal and that
EPA never responded to certain comments submitted on that proposal. The
commenter claimed that EPA did not demonstrate that the intrastate
trading program would achieve greater reasonable progress than the
January 2017 source-specific BART proposal to justify finalizing the
intrastate trading program in place of the source-specific BART FIP and
that EPA cannot ignore the findings it previously made in the January
2017 BART FIP proposal.
    Response: Under the notice and comment rulemaking process, EPA may
decline to finalize a proposed rule or may finalize a rule with changes
from the proposal based on consideration of additional information
received during the comment period. As a general matter, EPA may
publish a new proposed rule that supersedes a previously proposed rule
in order to take into account newly available information or changes in
circumstances that would affect the outcome of the final rule, with no
obligation to finalize the originally proposed rule. EPA's obligations
are to promulgate a final rule that meets the requirements of the Clean
Air Act and the Regional Haze Rule, consider and respond to all
relevant comments that are germane to the final rule, and provide a
record of decision-making for its action that is not arbitrary and
capricious. In this case, informed by comments we received during the
public comment period for the January 2017 proposal, and based on our
independent determination that this BART alternative approach under 40
CFR 51.308(e)(2) would meet all regulatory requirements and thus be a
viable approach for Texas, we addressed the SO2 BART
requirement for Texas EGUs under a BART alternative consisting of an
intrastate trading program in our October 2017 final rule instead of
finalizing the source-specific BART emission limits we had proposed. In
the October 2017 final rule, EPA considered and responded to all
comments germane to the final rule and provided a record of decision-
making for the final action. We note that some of the comments we
received on the January 2017 proposal raised specific issues related to
the analyses for the source-specific BART emission limits we proposed,
and those comments were no longer relevant once we determined not to
promulgate the proposed source-specific BART emission limits in our
final action. Therefore, a response to those comments was unnecessary.
While in this case, EPA did not publish a new proposal before issuing
the October 2017 final rule, we explained the basis for our
finalization of the BART alternative in that final action, and we
subsequently published a proposal in August 2018 to affirm our October
2017 final rule and solicited comment on important aspects of the rule,
as discussed in section II.A of this final action. Informed by comments
we received on the August 2018 proposed rule, we issued a supplemental
proposal that proposed changes to the Texas SO2 Trading
Program, as discussed in section II.B of this final action. Having made
the determination in the October 2017 final action, as further affirmed
in today's final action, that the BART-alternative program, as amended
in this final action, satisfies 40 CFR 51.308(e)(2) under the clear
weight of evidence test of 40 CFR 51.308(e)(2)(i)(E), EPA need not
further explain or justify the Texas SO2 Trading Program
based on a comparison of emission reductions, costs, or visibility
improvements that may have been potentially achieved had EPA finalized
the source-specific controls we proposed in January 2017. Further, in
response to the statement contending that EPA cannot ignore the
findings it previously made in the January 2017 proposed rule, we note
that those proposed source-specific BART analyses and control
determinations do not constitute final findings or final Agency action,
as they were proposed by EPA but not finalized.
    Comment: We received one comment asserting that the only
justification EPA provided for finalizing the intrastate trading
program in place of the source-specific BART FIP is that the state made
this request during the public comment period for the January 2017 BART
FIP proposal, and that this justification is inappropriate. The
commenter claimed that while the CAA does establish a

cooperative state-federal framework, this does not justify EPA
deferring to a State's expressed preferences without providing a valid
justification.
    Response: This comment mischaracterizes the basis for our
finalization of the Texas SO2 Trading Program in place of
source-specific BART controls in the October 2017 final action. While
we did explain in the October 2017 final action that we received
comments during the public comment period for the January 2017 proposal
from the Texas Commission on Environmental Quality (TCEQ), the Public
Utility Commission of Texas (PUC), Luminant, and American Electric
Power (AEP), urging us to consider as a BART alternative, the concept
of emission caps using CSAPR allocations,\149\ this was not the sole
basis for our finalization of the Texas SO2 Trading Program
in place of source-specific BART controls. Our October 2017 final
action promulgating the Texas SO2 Trading Program was
informed by comments we received during the public comment period for
the January 2017 proposal, and was based on our independent
determination that a BART-alternative approach under 40 CFR
51.308(e)(2) meets all statutory and regulatory requirements and is
thus an appropriate approach for addressing the SO2 BART
requirement for Texas EGUs. In addition to meeting all Clean Air Act
and Regional Haze Rule requirements, we also explained in the October
2017 final action that the Texas SO2 Trading Program would
result in lower costs and added flexibility for affected sources
compared to source-specific SO2 BART controls.
---------------------------------------------------------------------------

    \149\ 82 FR 48324 at 48327.
---------------------------------------------------------------------------

D. Statutory Requirements for FIP Promulgation and Implementation

    Comment: We received one comment asserting that the FIP
promulgating the Texas SO2 Trading Program is arbitrary,
capricious, and unlawful because it allows EPA to suspend key
provisions of the intrastate trading program if Texas submits a SIP
revision, without the need for EPA to approve the SIP before those key
provisions of the trading program are suspended. Specifically, the
commenter referred to a provision of the Texas SO2 Trading
Program that provides that the ``Administrator may delay recordation of
Texas SO2 Trading Program allowances for the specified
control periods if the State of Texas submits a SIP revision before the
recordation deadline.'' 40 CFR 97.921(a). Similarly, the trading
program includes a provision that provides that the ``Administrator may
delay recordation of the Texas SO2 Trading Program
allowances for the applicable control periods if the State of Texas
submits a SIP revision by May 1 of the year of the applicable
recordation deadline under this paragraph.'' Id. Sec.  97.921(b). The
commenter claimed that these provisions at 40 CFR 97.921(a) and (b) are
arbitrary and capricious and otherwise unlawful because they are
counter to the CAA's rulemaking requirements given that no provision of
the CAA allows the submission of a SIP to suspend implementation of a
FIP. The commenter also asserted that these provisions of the trading
program violate the CAA and the Regional Haze Rule because suspension
of the trading program would mean that there is no functioning BART
alternative in place in the interim period between state submission of
the SIP and EPA approval of that SIP. Furthermore, the commenter
expressed concern that the Texas SO2 Trading Program does
not include any provision that would resume the intrastate trading
program if the submitted SIP was subsequently found to be deficient.
    Response: After considering this comment, we proposed in our
November 2019 supplemental proposal to modify the Texas SO2
Trading Program recordation provisions at 40 CFR 97.921 to make clear
that submission of a SIP revision by the state does not cause any
change in implementation of those provisions unless and until the SIP
revision is approved by EPA. We are adopting that proposed modification
in this final action. As explained in section III.A.1 of this final
notice, we are taking final action to revise 40 CFR 97.921(a), (b), and
(c) of the Texas SO2 Trading Program to condition any
exceptions to scheduled allowance recordation activities on Texas'
submission and EPA's approval of a SIP revision, rather than just on
Texas' submission of a SIP revision. This revision will ensure that the
program remains fully operational unless it is replaced by a SIP
revision that is approved by EPA as meeting SO2 BART
requirements for the covered BART-eligible units.

E. Timing of the Plan for the First Implementation Period

    Comment: We received a comment that asserted that the first
planning period for regional haze ends in 2018 and given that the Texas
SO2 Trading Program would not be implemented until the
beginning of 2019, it followed that the Texas SO2 Trading
Program and any other BART alternative for Texas would not meet the
timing requirement for a BART alternative at 40 CFR 51.308(e)(2)(iii).
The commenter also argued that EPA's position in the October 2017 final
rule that the end of the first planning period of the first long-term
strategy for Texas is 2021 and thus the Texas SO2 Trading
Program meets the timing requirement for a BART alternative is
unsupported and is inconsistent with EPA's prior statements identifying
2018 as the close of the first planning period. The commenter asserted
that EPA's position that the January 2017 revisions to the Regional
Haze Rule extended the first planning period contradicts EPA's
statements in the January 2017 rulemaking that the revisions to the
Regional Haze Rule did not alter the requirements for the first
planning period. Additionally, the commenter later asserted, in
response to our supplemental proposal to add an assurance level to the
Texas SO2 Trading Program, that EPA cannot guarantee the
trading program will actually achieve emissions reductions until the
addition of the assurance provisions becomes effective and that given
that the limitations imposed by the assurance level would not be
implemented until the 2021 compliance period, EPA cannot guarantee that
emission reductions under the trading program will actually take place
during the first planning period.
    A similar comment submitted by New Jersey asserted that the 2017
Regional Haze Rule revisions extended the time to submit Regional Haze
plan revisions for the second planning period from 2018 to 2021, but
did not extend the date for implementation of BART requirements
associated with the first planning period. New Jersey asserted that
under the Regional Haze Rule, emission reductions needed in the first
planning period are still due by December 31, 2018 and that allowing
Texas to obtain the reductions by the end of 2019, as allowed under the
Texas SO2 Trading Program, negates the intent of the CAA
(specifically the 10-year planning period to assure incremental
progress) and puts additional burden on other contributing states to
maintain progress.
    Response: After reviewing the Agency's position in the January 2017
final rule making amendments to the Regional Haze Rule, we are not
finalizing a position in this action that the first planning period has
been extended to July 31, 2021. We agree with the commenter that this
position would be at odds with the national finding in the January 2017
action that our amendments there ``do not affect the

development and review of state plans for the first implementation
period . . . .'' 82 FR at 3080. Nonetheless, the Texas SO2
Trading Program satisfies the requirement of 51.308(e)(2)(iii),
because, as discussed in section III.A.2 above, the program ensures
that emission reductions that were achieved prior to the end of 2018,
sufficient to meet the requirements of the BART alternative, will be
maintained through an enforceable program.
    Actual emission levels from the sources covered by the BART
alternative were below the levels mandated by the alternative by the
end of the first planning period. In the case of the Texas
SO2 Trading Program, sources subject to the trading program
were already emitting SO2 at levels below the program budget
prior to December 31, 2018. As discussed in our November 2019
supplemental proposal, the combined SO2 emissions from Texas
EGUs participating in the intrastate trading program were 179,630
SO2 tons in 2018, which is well below the Texas
SO2 Trading Program budget of 238,395 tons (as well as the
assurance level of 255,083 tons we are finalizing in this action).\150\
Therefore, the emissions reductions secured under the trading program
occurred prior to the end of the period of the first long-term strategy
for regional haze. With the trading program taking effect with the
start of the 2019 calendar year, actual emissions were never allowed to
exceed the amounts called for by the BART alternative. This issue is
further discussed above in section III.A.2. We also note that we have
never stated and do not agree that the existing Texas SO2
Trading Program fails to ensure that all necessary emission reductions
will occur by the end of the first planning period even without the
addition of the assurance provisions. Our purpose in proposing to add
the assurance provisions was merely to further ensure that the
program's design is at least as stringent as the CSAPR SO2
program as applied to Texas, not only on an average annual basis but
also in individual years. Given that actual emission levels from the
sources covered by the BART alternative were below the levels mandated
by the alternative by the end of the first planning period, even before
the addition of the assurance level, we are determining that the Texas
SO2 Trading Program meets the timing requirement for a BART
alternative at 40 CFR 51.308(e)(2)(iii).
---------------------------------------------------------------------------

    \150\ 84 FR 61853.
---------------------------------------------------------------------------

F. Notice and Comment Requirements

    Comment: We received a comment that the FIP promulgating the Texas
SO2 Trading Program did not follow the Clean Air Act's
procedural requirements for promulgating a FIP. The commenter claimed
that EPA promulgated the FIP without following the public notice and
comment procedures set forth in 42 U.S.C. 7607(d)(1)(B), (d)(2)-(6),
which the commenter contended violates the Clean Air Act. The commenter
contended that the Clean Air Act's public notice and comment procedures
at U.S.C. 7607(d)(3) require that EPA first publish in the Federal
Register a proposed rule that includes a statement of basis and purpose
and specifies a comment period. The commenter claimed that this
statement of basis and purpose must include a summary of the factual
data on which the proposed rule is based, the methodology used in
obtaining and analyzing the data, and the major legal interpretations
and policy considerations underlying the proposed rule, and that EPA
must allow any person to submit comments as well as give interested
persons an opportunity for the oral presentation of data, views, or
arguments. The commenter asserted that these and other public
participation requirements in Sec.  7607(d) build on those in the
Administrative Procedure Act and are even more protective of the
public's right to notice and comment. The commenter asserted that EPA's
January 2017 proposed rule ``established'' source-specific
SO2 emission limits that would have required the
installation and operation of modern SO2 controls or
upgraded controls for subject to BART Texas EGUs, and that in contrast
to this, the Trading Program in the final rule consisted of an
intrastate emissions trading program that was not presented in the
proposal. The commenter contended that EPA did not follow the
rulemaking procedures required by the CAA given that EPA never proposed
the adoption of a trading program nor did it discuss that it might
consider adopting an intrastate trading program for Texas in lieu of
the source-specific retrofit controls proposed in the January 2017
proposal. Additionally, the commenter asserted that the FIP
promulgating the Texas SO2 Trading Program does not qualify
as a logical outgrowth of the January 2017 proposal. The commenter
contended that the logical outgrowth doctrine applies where a rule
merely clarifies its proposal, or where the agency put commenters on
notice that it was considering approaches different from the proposal.
According to the commenter, the logical outgrowth doctrine does not
apply in this case because (i) the intrastate trading scheme is
different than the January 2017 BART proposal, and (ii) EPA did not
provide notice that it was considering an intrastate trading program
instead of source specific SO2 emission limits.
    Response: We explained in our October 17, 2017 final rule that
during the comment period for our January 2017 proposed rule, we
received a comment letter from the Texas Commission on Environmental
Quality (TCEQ) and the Public Utility Commission of Texas (PUC),\151\
urging us to consider as a BART alternative the concept of emission
caps using CSAPR allocations. We also received similar comments from
Luminant and American Electric Power (AEP). Based on our consideration
of these comments and our independent determination that a BART
alternative approach under 40 CFR 51.308(e)(2) would meet all
regulatory requirements and thus be a viable approach for Texas, we
proceeded to address the SO2 BART requirement for Texas EGUs
under a BART alternative consisting of an intrastate trading program in
our October 2017 final rule. In response to a petition for
reconsideration of the October 2017 final rule requesting that the
Administrator reconsider certain aspects of the FIP related to the
Texas SO2 Trading Program, we decided that the October 2017
federal plan could benefit from further public comment.\152\ As a
result, in our August 27, 2018 proposed rule, we proposed to affirm our
October 2017 final rule that approved a portion of the 2009 Texas
Regional Haze SIP and promulgated the intrastate trading program FIP.
In doing so, we provided the public with an opportunity to comment on
all centrally relevant aspects of our Texas SIP approval and of the FIP
that promulgated the Texas SO2 Trading Program, including
our proposal to affirm the October 2017 FIP establishing an intrastate
trading program capping emissions of SO2 from certain EGUs
in Texas as a BART alternative and our determination that this program
satisfies the requirements for a BART alternative. We provided a 60-day
public comment period that ended on October 26, 2018, and held a public
hearing on September 26, 2018. Following that notice and comment
opportunity, the EPA determined that certain additional changes to the
program not included in the August 2018 proposal could be warranted.
Therefore, we issued a

supplemental notice of proposed rulemaking on November 14, 2019,
providing a 60-day comment period and a public hearing on December 9,
2019. In the November 2019 supplemental proposal,\153\ we proposed to
amend several provisions of the Texas SO2 Trading Program
with the overall objective of strengthening our finding in the October
2017 final rule,\154\ which we proposed to affirm in August 2018,\155\
that the Texas SO2 Trading Program will result in
SO2 emission levels from Texas EGUs that are similar to or
less than the emission levels from Texas EGUs that would have been
realized had Texas continued to participate in the SO2
trading program under CSAPR.\156\ The amendments to the Texas
SO2 Trading Program we are finalizing in this action are
designed to ensure that emission levels in each year under the
intrastate trading program, and their aggregate impact on visibility,
will be similar to or less than what would have been realized from
Texas EGUs from participation in the SO2 trading program
under CSAPR,\157\ thus providing further support to our determination
that the trading program meets the requirements for a BART alternative.
In finalizing our action affirming the intrastate trading program as
amended in this final action, the EPA is addressing all in-scope
comments we have received on both the August 2018 and November 2019
proposal notices, including, as discussed elsewhere in this final
action and in our separate Response to Comments document, comments
regarding the lawfulness and basis for the intrastate trading program
under the CAA and the Regional Haze Rule, and other related comments.
Therefore, to the extent the commenter is alleging that the intrastate
trading program in our October 2017 FIP was promulgated without
following the public notice and comment procedures and public
participation requirements set forth in 42 U.S.C. 7607(d), the agency
has cured any such alleged procedural defect.
---------------------------------------------------------------------------

    \151\ 82 FR 48324 at 48327.
    \152\ 83 FR 43586.
    \153\ 84 FR 61850, 61851.
    \154\ 82 FR 48324, 48329.
    \155\ 83 FR 43591.
    \156\ See 83 FR at 43599.
    \157\ 83 FR 43592.
---------------------------------------------------------------------------

    Comment: We received one comment asserting that EPA cannot claim
that the October 2017 trading program was a clarification of the
January 2017 proposed rule. The commenter asserted that the Texas
SO2 Trading Program finalized by EPA in the October 2017
final rule differs in substance from the BART proposal, which the
commenter claimed is evidenced by EPA's addition in the final action of
dozens of pages of regulatory and explanatory text that was not
included in the 2017 BART proposal.
    Response: We agree that our October 17, 2017 final rule that
promulgated an intrastate trading program to address the SO2
BART requirement for Texas EGUs cannot be characterized as merely a
clarification of our January 4, 2017 proposed rule, nor has the Agency
made this claim. Based on our consideration of comments we received on
the January 2017 proposal urging us to consider as a BART alternative
the concept of emission caps using CSAPR allocations, and based on our
independent determination that a BART alternative approach under 40 CFR
51.308(e)(2) would meet all regulatory requirements and thus be a
viable approach for Texas, we proceeded to address the SO2
BART requirement for Texas EGUs under a BART alternative consisting of
an intrastate trading program in our October 2017 final rule. In that
final rule, EPA considered and responded to all relevant comments
germane to the final rule and provided a record of decision-making for
the final action. We note that some of the comments we received on the
January 2017 proposal raised specific issues related to our proposed
analyses for the source-specific BART emission limits we proposed.
Given that those source-specific emission limits were not part of our
final action, providing substantive responses to such comments was not
required as they were no longer relevant. As discussed in several
places throughout this final action, in response to a petition for
reconsideration of the October 2017 final rule requesting that the
Administrator reconsider certain aspects of the FIP related to the
Texas SO2 Trading Program, we provided an opportunity for
further public comment on all centrally relevant aspects of the Trading
Program in a proposal published on August 27, 2018, and provided an
opportunity for public comment on proposed amendments to certain
provisions of the Trading Program in a supplemental proposal published
on November 14, 2019. The amendments to the Texas SO2
Trading Program we are finalizing in this final action, which include
minor changes from what we proposed in the November 2019 proposal, are
designed to ensure that emission levels in each year under the
intrastate trading program, and their aggregate impact on visibility,
will be similar to or less than what would have been realized from
Texas EGUs from participation in the SO2 trading program
under CSAPR,\158\ thus providing further support to our determination
that the Texas SO2 Trading Program meets the regulatory
requirements for a BART alternative and is an appropriate approach for
addressing Texas' SO2 BART obligations.
---------------------------------------------------------------------------

    \158\ 83 FR 43592.
---------------------------------------------------------------------------

    Comment: We received one comment contending that the Texas
SO2 Trading Program cannot be characterized as a logical
outgrowth of the December 2014 proposed rule given that the BART
provisions in the December 2014 proposed rule were abandoned due to
Homer City II, and that EPA otherwise took final action on that
proposed rule in a final action published in January 2016. The
commenter also asserted that further confirmation that the December
2014 proposal was part of a different rulemaking process is provided by
the fact that in the January 2017 BART proposal, EPA did not invite
comments on the December 2014 proposal and also that EPA did not
include the December 2014 proposal or any of the supporting technical
analysis for the December 2014 proposal in the docket for the January
2017 proposal on the date of the publication of the proposed rule, as
required by the CAA at 42 U.S.C. 7607(d)(3).
    Response: This commenter is referring to our December 16, 2014
proposed rule in which we proposed, among other things, to rely on our
CSAPR FIP requiring Texas sources' participation in the CSAPR trading
programs to satisfy the NOX and SO2 BART
requirements for Texas' BART-eligible EGUs.\159\ Due to the uncertainty
arising from the D.C. Circuit's remand of Texas' CSAPR budgets, when we
finalized the December 2014 proposal in an action published in January
2016, we did not finalize our proposal to rely on CSAPR to satisfy the
SO2 and NOX BART requirements for Texas
EGUs.\160\ We note that we did not attempt to characterize the Texas