--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Emission                         Annual               Emission rate
              Coronado 1 control technology                factor  (lb/      Heat rate       capacity    --------------------------------    Emissions
                                                            MMBtu) \1\      (MMBtu/hr)        factor          (lb/hr)          (tpy)      removed  (tpy)
--------------------------------------------------------------------------------------------------------------------------------------------------------
OFA (only)..............................................           0.407           4,316            0.84           1,756           6,462  ..............
LNB+OFA.................................................           0.303           4,316            0.84           1,308           4,811           1,651
SNCR w/LNB+OFA..........................................           0.212           4,316            0.84             915           3,368           3,095
SCR w/LNB+OFA...........................................           0.050           4,316            0.84             216             794           5,669
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Annual average basis.

    Cost-effectiveness values for each control technology are
summarized in Table 17, and are based on the total annual costs and
annual emissions removed listed in the previous tables.

                             Table 17--Coronado 1: Control Option Cost-Effectiveness
----------------------------------------------------------------------------------------------------------------
                                                                                Cost-effectiveness  ($/ton)
          Coronado 1 control technology            Total annual      Emissions   -------------------------------
                                                   cost  ($/yr)   removed  (tpy)       Avg.            Incr.
----------------------------------------------------------------------------------------------------------------
OFA (only)......................................  ..............  ..............  ..............  ..............
LNB+OFA.........................................        $613,554           1,651            $372  ..............
SNCR w/LNB+OFA..................................       7,166,781           3,095           2,316           4,540
SCR w/LNB+OFA...................................      12,103,941           5,669           2,135           1,918
----------------------------------------------------------------------------------------------------------------

    Based on SRP's capital and O&M cost estimates, we still consider
the cost-effectiveness values of SCR, on an average ($2,135/ton) and
incremental ($1,918/ton) basis, to not be cost-prohibitive. We consider
these results supportive of our proposed determination that SCR with
LNB and OFA is cost-effective. We note that while the LNB and OFA
option is the least expensive (i.e., lowest annual cost) and is the
most cost-effective of the control technologies (i.e., has the lowest
$/ton value), it is also the least effective control option (i.e.,
removes smallest quantity of NOX). It removes substantially
fewer emissions than either of the other two control options, the SNCR-
and SCR-based systems. As discussed in our proposed action, and in
other responses in this document, we have not identified any energy or
non-air quality impacts that warrant eliminating SCR from consideration
for Coronado Unit 1. Combined with the modeled visibility improvement
associated with the SCR control option, SRP's cost estimates continue
to support the selection of SCR with LNB and OFA as BART for Coronado
1.
    Comment: One commenter (SRP) stated that the proposed rule and the
TSD say almost nothing about how IPM was used to calculate costs,
instead directing the public to an EPA contractor report for more
information. The commenter asserted that no contractor report in the
docket for the rulemaking supplies additional detail on precisely how
IPM was used. The commenter added that this failing renders EPA's
proposed rule inconsistent with the CAA's public notice requirements.
    Response: We disagree with the commenter's assertion that we have
not provided sufficient information regarding our cost calculations. In
the e-docket for our proposal, we included the raw cost calculation
spreadsheets from our contractor that contain the IPM equations,
corresponding variable values, selected notes regarding assumptions and
variable ranges, as well as selected tables from the IPM Base Case
v4.10.\203\ In addition, Web links were provided (both in the raw cost
calculation spreadsheet and in our proposal) to the location on the
publicly available EPA Web site that contains full IPM documentation.
---------------------------------------------------------------------------

    \203\ Document ID: EPA-R09-OAR-2012-0021-0008, File name: G-15--
MODELING--FILES--EGU--BART--Costs--Apache--Cholla--Coronado--FINAL2.
---------------------------------------------------------------------------

    Comment: One commenter (SRP) stated that EPA failed to follow the
BART Guidelines by not conducting an incremental cost analysis for
Coronado. According to the commenter, the proposed rule and TSD both
provide a single entry for incremental costs for each of the Coronado
units that reflect the incremental cost of the most stringent
NOX BART control option compared to the baseline. The
commenter asserted that this is not a complete incremental analysis
because it ignores incremental comparisons between identified control
options. SRP contended that in the absence of a proper NOX
BART assessment, the proposed rule lacks an adequate foundation. The
commenter stated that the high incremental costs of post-combustion
NOX control technologies when compared to combustion control
technologies reinforces the conclusion that post-combustion control
technologies cannot be the basis for BART for the units at Coronado.
    Response: We disagree with the commenter's assertion that we did
not perform a sufficient incremental cost analysis for the Coronado
units. In our control cost summaries (Table 22 in the proposed rule and
Table 32 in the TSD), the column labeled ``incremental cost-
effectiveness'' represents the $/ton of the control option when
compared to the preceding control option. The column labeled ``average
cost-effectiveness'', represents the $/ton of the control option when
compared to the baseline control. In the case of Coronado Unit 1, we
considered two control options beyond the baseline: SNCR with LNB and
OFA, and SCR with LNB and OFA. The ``single entry for incremental
costs'', as described in the comment, represents the incremental cost
between the SNCR- and SCR-based options. An incremental cost value was
not calculated between LNB with OFA (which is the option preceding the
SNCR-based option) and SNCR because LNB with OFA represented the
baseline control in our analysis. The cost-effectiveness of moving from
LNB with OFA to SNCR with LNB and OFA is therefore

adequately captured in the ``average cost-effectiveness'' column. We do
note that, in our supplemental cost analysis, we have used OFA as the
baseline control, and have therefore calculated an incremental cost-
effectiveness value for moving from LNB with OFA to SNCR with LNB and
OFA. These results are described in a previous comment and, as noted in
that comment, we disagree with the commenter's assertion that the
incremental cost of post-combustion controls is cost-prohibitive.
d. Visibility Improvement
    Comment: One commenter (SRP) asserted that EPA is without basis for
establishing in the proposed rule a 0.5 deciview comparison threshold
as a touchstone for analyzing impacts from Coronado BART controls,
citing the BART Guidelines and associated preamble. According to the
commenter, even if EPA could impose a 0.5 deciview comparison
threshold, it is only by substituting its own preferred modeling
methodology (which the commenters argued is something EPA cannot
lawfully do) that EPA can project that requiring SCR at Unit 1 would
barely yield a projected improvement of more than 0.5 deciview at one
area. The commenter also noted that 0.5 deciview is below the level of
human perceptibility.
    Response: As explained above, we have not used 0.5 dv as a
threshold, but as one point of comparison such as a ``benchmark'' or
``yardstick'' to gauge the magnitude of impacts under various control
scenarios.
e. Other Comments
    Comment: The commenter (NPS) agreed with EPA's determination that
NOX BART for Coronado Units 1 and 2 is SCR with LNB and OFA.
The commenter noted that EPA proposed on Unit 1 an emission limit for
NOX of 0.050 lb/MMBtu, based on a rolling 30-boiler-
operating-day average, and on Unit 2 an emission limit of 0.080 lb/
MMBtu, which is consistent with the emission limit in the consent
decree. The commenter stated that EPA acknowledged that the emission
limit for Unit 2 established in the consent decree was not the result
of a BART five-factor analysis, and that the consent decree does not
indicate that SCR at 0.080 lb/MMBtu represents BART. The commenter
commended EPA for soliciting additional information on the feasibility
of achieving a more stringent limit.
    Response: We acknowledge the comment.
    Comment: In response to EPA's proposed BART determination in the
proposed FIP, one commenter (SRP) performed and submitted an assessment
of the critical components of a BART analysis for Coronado, including
control costs and the visibility improvements associated with the
control options. The commenter indicated that this analysis shows that
even without considering other energy and non-air quality environmental
impacts associated with the implementation of SNCR or SCR, it is clear
that the visibility benefits realized from implementation of post-
combustion controls are not justified by the cost. The commenter also
submitted the results of this analysis using CALPUFF version 6.42 in
place of version 5.8. The commenter stated that this analysis provides
even stronger evidence that selection of post-combustion controls as
BART for Coronado is inappropriate.
    Response: We disagree with this comment. As noted in a separate
response, we have performed a supplemental cost analysis that relies
upon many elements of the cost analysis provided by the commenter. Even
with the higher cost estimates provided by the commenter, we consider
the costs of post-combustion controls such as SNCR and SCR to be cost-
effective on a $/ton basis. In addition, as noted in a separate
response, we disagree with several assumptions used in the commenter's
visibility modeling, such as the use of an unapproved CALPUFF model
version and treatment of ammonia background concentrations. We
therefore disagree that the visibility benefits modeled by the
commenter are representative of the benefits that will accrue with the
use of post-combustion controls. The modeling results performed in
support of our proposal indicate substantial visibility benefits,
especially with the SCR control option. As a result, we do not consider
it appropriate to eliminate either of the post-combustion controls from
consideration as BART. Although SCR is the most stringent control
option, its associated visibility benefits and cost-effectiveness
justify this technology as BART.

E. Comments on Enforceability Requirements in EPA's BART FIP

    Comment: One commenter (SRP) made the following points concerning
the proposed enforceability requirements:
     EPA must modify the monitoring requirements to be
consistent with existing requirements. If EPA proceeds to impose
additional controls at Coronado beyond those specified in the consent
decree and already included in the Coronado permit, it must align these
requirements to eliminate unnecessary and unreasonable compliance
burdens.
     The commenter supports and appreciates the use of the
monitoring system certification and quality assurance (QA) procedures
in 40 CFR Part 75. However, EPA's proposed definition of ``valid'' data
is broader than 40 CFR Part 75, and EPA also should make clear that the
``bias'' adjustment procedures in 40 CFR Part 75 do not apply to data
used to calculate the 30-day rolling averages.
     The commenter objects to the proposed additional relative
accuracy requirements. Imposing additional relative accuracy test audit
(RATA) specifications will not increase the accuracy of any monitoring
system, but would increase the difficulty and cost of testing. It also
could result in additional missing data if tests must be repeated to
meet the specifications. To proceed with combined RATA specifications,
EPA also would need to either propose (and solicit comment on)
alternative low-emitter combined specifications that have been
demonstrated to be consistently achievable, or exempt units meeting any
of the applicable 40 CFR Part 75 low-emitter thresholds from those
specifications.
     The commenter stated that the proposed data availability
requirements are unnecessary and too stringent. Source owners and
operators already have sufficient incentive to obtain valid data in
order to avoid the increasingly conservative (and ultimately punitive)
missing data substitution procedures that apply under 40 CFR Part 75.
Regarding stringency, if a unit has a significant missing data event
during a calendar quarter in which it also has a significant period of
unit downtime (e.g., as a result of an outage), the percent of
operating hours during the quarter with valid data could easily be less
than 90 percent. It is in part for this reason that 40 CFR Part 75
measures data availability over each 8,760-operating-hour period. EPA
should either eliminate the unnecessary requirement or provide data to
justify its proposed requirement that take into account the differences
described above.
     EPA must modify the quarterly reporting requirements to be
consistent with existing requirements.
     EPA must modify the notification requirements in the
proposed rule because they are overly broad and overly prescriptive.
First, EPA should clarify the proposed provision by requiring notice
only of new controls that will be required to meet the FIP or regional
haze SIP. Second, because installation of controls is a complex
process, and the point at which that

process is ``complete'' may not be immediately clear, EPA must revise
the requirement to use a more objective term and allow sufficient time
for owners and operators to comply. Third, because the proposed
requirement duplicates reporting already required for a new add-on
NOX emission control under 40 CFR Part 75, EPA should rely
on (and if necessary refer to) the notice required under Part 75.
    Response: We partially agree with this comment and are adjusting
the enforceability requirements of the final FIP accordingly. EPA
agrees that the Part 75 bias adjustment should not be applied to the
compliance data for the BART rules in this action and is making changes
to the final rule to address this comment. However, EPA does not agree
that only the incentives under the Acid Rain Part 75 rules are
sufficient to assure adequate valid data for this rule. Part 75 relies
on progressively punitive data substitution procedures to promote good
valid data availability for its program. Our rule does not substitute
data, so the incentives of the Part 75 rules do not exist. Therefore,
EPA is requiring that each unit subject to this rule obtain 90 percent
valid data, as determined under Part 75, for each calendar year.
    It should be noted that the commenter did not submit any data
specific to its EGUs indicating the difficulty of meeting the proposed
valid data availability requirements. Also, the other two utility
companies affected by this rule did not make any objection to the
proposed data requirements. However, EPA, as a result of this comment,
has reconsidered the additional quality assurance and valid data
requirements from the proposal. As indicated by the commenter,
measurement and QA requirements for NOX lb/hour are not
currently required by Part 75. In addition, EPA recognizes that the
calculation of heat input requires the combination of the flow and
diluent (O2 or CO2) CEMS along with measurements
of temperature and estimation of moisture. In addition in the final
rule, EPA is providing for a multi-unit determination of compliance.
This would compound the valid data concerns of the commenter. EPA
requires monitoring data used for compliance determinations to be of
known quality as demonstrated through Quality Assurance/Quality Control
(QA/QC) procedures.\204\ In place of the requirement to validate
through RATA testing of the NOX lb/hour measurement and heat
input, EPA will require that all of the CEMS required by Part 75 and
used for the compliance demonstrations for this action obtain 90
percent valid data (per Part 75 specifications) for each unit over each
calendar year. In addition, the rule will require the affected units to
conduct RATA evaluations and calculate the quarterly valid data hours
for NOX lb/hour and heat input. EPA will not finalize the
minimum data requirements in the proposal, but will require these data
to be calculated (all data for determining the relative accuracy in
these units are available when Part 75 RATAs are performed) and
reported to both EPA and ADEQ to determine if these data are capable of
meeting more rigorous QA/QC requirements in the future. We also note
that the final rule will add QA/QC and minimum valid data requirements
for the inlet SO2 CEMS that are needed to calculate the
SO2 removal efficiencies for the Cholla EGUs. Finally, EPA
agrees that semiannual reporting will be sufficient for this rule, and
the final rule will reflect this.
---------------------------------------------------------------------------

    \204\ See, e.g., 40 CFR 60.13(a) and 40 CFR Appendix F.
---------------------------------------------------------------------------

    Comment: One commenter (AEPCO) requested that EPA clarify that
AEPCO has longer than 180 days to comply with the non-SCR limits. The
commenter is particularly concerned about the time needed for the ESP
and scrubber upgrades and believes a five-year period for all BART
implementation would be appropriate. ADEQ also commented that the
facility will need more than 180 days to complete the upgrades needed
to meet the SO2 BART limits, and stated that a five-year
compliance time frame from the time the BART limit is finalized, as
specified in RHR Appendix Y, is most appropriate.
    Response: EPA agrees that AEPCO would need more than the 180 days
in the proposed rule. However, we do not agree that five years is
necessary to perform the necessary upgrades. The final rule will
require AEPCO's two units to meet the SO2 and
PM10 limits within four years of the effective date of this
rule. This time frame will allow AEPCO to perform the upgrades to the
two units during regularly scheduled maintenance outages.
    Comment: Several commenters (ADEQ, AEPCO, APS, EarthJustice, NPS,
SRP) provided feedback on test methods. AEPCO supported maintaining the
use of EPA Method 201A to comply with the proposed BART PM10
limits. In contrast, ADEQ and APS only supported the use of Methods
201A and 202 if SCR controls are not used. These commenters stated that
SCR causes an increase in sulfuric acid aerosol mist, which results in
an increase in condensable particulate matter. APS suggested Methods 1-
4 and Method 5 or 5e are appropriate where SCR is used. ADEQ suggested
Method 5 or 5e where SCR is used, and states that any collateral
increase in acid mist should be addressed through a permitting process.
SRP stated that wet scrubbers also render Methods 201 and 201A
inapplicable, and requested that EPA specify the use of Method 5, 5B,
5I or an approved alternative.
    One commenter (NPS) pointed out that use of SCR at these units is
expected to result in increased condensable particulate matter in the
form of sulfuric acid mist (H2SO4), which would
have the effect of making the emission limit more stringent than
intended by ADEQ, and likely not be achievable in practice. To address
EPA's request for comment on whether to allow compliance with the
PM10 limit to be demonstrated using test methods that do not
capture condensable particulate matter, namely EPA Methods 1 through 4
and Method 5 or Method 5e, the commenter conducted and submitted an
analysis of H2SO4 emissions. According to the
commenter, H2SO4 emissions will not be
significant, contributing less than 10 percent to the PM10
limit. The commenter suggested that the 0.030 lb/MMBtu limit proposed
by ADEQ for the Apache and Coronado units be adjusted to 0.033 lb/MMBtu
to reflect the increase in total PM10 attributable to SCR,
and that PM10 emissions would be measured by conducting EPA
Method 201A/202 tests consistent with the ADEQ's SIP.
    In contrast to the previous commenters, one commenter
(Earthjustice) stated that EPA should approve the test methods in the
ADEQ RH SIP (i.e., EPA Methods 201 and 202) and ensure that the BART
limit includes both filterable and condensable PM fractions. The
commenter asserted that if EPA allows or requires a test method other
than Method 201 and 202, the PM10 BART emission limit would
effectively be less stringent because it would only apply to filterable
PM, and not total PM. The commenter indicated that requiring different
test methods would in effect be proposing an even less-stringent
PM10 BART limit, which would require EPA to undertake an
independent BART analysis that demonstrates that the less-stringent
emission limit is BART. Consequently, according to the commenter, if
EPA requires or allows a different test method, it must lower the
emission limit to reflect only the filterable PM10 fraction.
The commenter added that in this case, EPA should ensure that
compliance with the filterable PM10 limit is demonstrated
with use of CEMS

for filterable PM, which is currently available.
    Response: ADEQ selected test methods 201 and 202 for determining
compliance with this limit. EPA noted in the proposal that the proposed
addition of SCR for NOX control would likely increase the
quantity of PM collected as condensable PM by method 202 due to an
increase in H2SO4 from the oxidation of
SO2 to SO3. EPA requested comment on changing the
test method from methods 201 and 202 to EPA Method 5 which measures
only the filterable PM. Method 5 measures all sizes of filterable PM
which results in a higher filterable PM value than Methods 201 or
Method 201A, which only measure filterable PM10.
    In its comments concerning the proposal for Coronado, SRP noted
that Method 201A cannot be used in a wet exhaust gas stream. We agree
with this comment. In promulgating amendments to Method 201A and Method
202 in 2010, EPA explained that:

    Method 201A cannot be used to measure emissions from stacks that
have entrained moisture droplets (e.g., from a wet scrubber stack)
since these stacks may have water droplets that are larger than the
cut size of the PM10 sizing device. The presence of
moisture would prevent an accurate measurement of total
PM10 since any PM10 dissolved in larger water
droplets would not be collected by the sizing device and would
consequently be excluded in determining total PM10 mass.
To measure PM10 in stacks where water droplets are known
to exist, EPA's Technical Information Document 09 (Methods 201 and
201A in Presence of Water Droplets) recommends use of Method 5 of
appendix A-3 to 40 CFR part 60 (or a comparable method) and
consideration of the total particulate catch as PM10
emissions.\205\
---------------------------------------------------------------------------

    \205\ 75 FR 80118, 80121.

It is also true that the rarely used Method 201 cannot be used in a wet
exhaust stream (also known as a ``wet stack'').\206\
---------------------------------------------------------------------------

    \206\ See EPA's Technical Information Document 09, ``Methods 201
and 201A in Presence of Water Droplets'' (September 9, 1991).
---------------------------------------------------------------------------

    At this time, the three facilities subject to this BART rule have a
mix of wet and dry stacks. EPA anticipates that the SO2 BART
limits set by ADEQ will result in 100 percent of the exhaust gas
undergoing SO2 scrubbing. Neither ADEQ nor EPA is requiring
reheat of the exhaust gas stream. Therefore, it is likely that all of
the coal-fired units covered by this action will have wet stacks. So it
is doubtful that any filterable PM10 method would work as
the compliance method.\207\ Therefore, EPA is finalizing a decision to
allow either Method 5 or Methods 201A and 202 for demonstrating
compliance with the BART PM10 limits set by ADEQ.
---------------------------------------------------------------------------

    \207\ See, e.g. 75 FR 80126 (``Monitoring the emission of
PM10 or PM2.5 from a wet gas stream is a
challenging problem that has not been addressed successfully despite
considerable effort. A consensus method to provide this information
has not emerged.'')
---------------------------------------------------------------------------

    As noted above, the addition of the SCR to these EGUs for
NOX control will likely increase the condensable PM that
will be measured by Method 202. By offering the option of Method 5 or
Methods 201A and 202, the facilities can determine which methods are
compatible with their units' stack conditions and will best demonstrate
the proper operation of their PM controls. Any significant increase in
H2SO4 and the appropriate control of this
visibility impairing pollutant will be addressed through the PSD
permitting process with a BACT determination for
H2SO4 control. The significance level that
triggers permitting for H2SO4 is an increase of
seven tons per year of this pollutant.\208\ Coronado has already
received a PSD permit for H2SO4 that is likely to
result from the increase in H2SO4 resulting from
the SCR required under the consent decree.
---------------------------------------------------------------------------

    \208\ See 40 CFR 52.21(b)(23)(i).
---------------------------------------------------------------------------

    EPA's AP-42 indicates that approximately one third of the
filterable PM emissions from EGUs are larger than PM10. This
means that the change from Method 201 (or 201A) to Method 5 as the
compliance method will result in this increased measurement of PM. This
is offset by the elimination of the condensable measurement of Method
202 and as noted above, the utilities will have the option of using
either testing approach.
    Comment: One commenter (APS) requests that EPA change the
compliance date for the PM10 limit at Cholla Unit 2 to
January 1, 2016, rather than January 1, 2015. The commenter explained
that EPA misunderstood the language of the ADEQ SIP, which refers to
APS's commitment to install a fabric filter by 2015, to mean
installment and operation by the first of the year, whereas this
commitment actually meant by the end of 2015, or December 31, 2015. The
commenter further requested that this date be extended to April 16,
2016, if the ADEQ approves APS's request for a one-year extension to
comply with the Mercury and Air Toxics Standards (MATS) before EPA
finalizes this BART determination.
    The commenter also requested that EPA change the compliance date
with the 0.15 lb/MMBtu SO2 emissions standard from 180 days
after promulgation to January 1, 2016, or April 16, 2016, to allow
sufficient time to do the necessary upgrades for Unit 2. This unit will
require scrubber upgrades that need to be done concurrent with the
fabric filter installation to accommodate the increase in pressure drop
that a new fabric filter will impose. ADEQ also stated a compliance
date of April 1, 2016, would be more appropriate than January 1, 2015,
for both the PM10 and SO2 limits at Cholla Unit
2.
    Response: EPA agrees with this comment and has changed the
compliance date in the final rule to April 1, 2016.\209\ In addition,
as explained above, in order to ensure that the wet FGD (i.e.
scrubbers) on all three units at Cholla are properly operated and
maintained, consistent with 40 CFR 51.308(e)(1)(v), we are finalizing a
removal efficiency requirement for SO2 of 95 percent on a
30-day rolling basis for Cholla Units 2, 3 and 4. Compliance with the
efficiency requirement will be determined by SO2 continuous
emission monitoring systems (CEMS) operated at the inlets and outlets
of the scrubbers. Units 3 and 4 already have SO2 and
CO2 CEMS installed after the scrubbers, and Unit 2 has
SO2 and CO2 CEMS installed before the
scrubbers.\210\ Therefore, SO2 and diluent CEMS will need to
be installed at the inlets to the scrubbers on Units 3 and 4. We
estimate that the total annualized cost for this installation
(including ongoing operation and maintenance costs) will be
approximately $51,000 per unit.\211\ We also note that this efficiency
requirement will probably result in a slight increase in operation and
maintenance costs in the form of additional limestone and scrubber
waste disposal expenses. Even considered collectively, these additional
costs are de minimis in comparison to the annualized cost of SCR (i.e.,
$9,906,206 to $13,590,853 per unit at Cholla, according to our
supplemental cost analysis) or the total cost of installing a new wet
FGD system, which APS has estimated to be $67.0 to $70.9 million.\212\
In order to allow sufficient

time for installation of the CEMS, the compliance deadline for this
removal efficiency requirement at these units will be one year after
publication of this final rule for Units 3 and 4. The removal
efficiency compliance deadline for Unit 2 will coincide with the
compliance date for the lb/MMBtu SO2 emission limit for this
unit (i.e., April 1, 2016).
---------------------------------------------------------------------------

    \209\ Although APS requested a deadline of April 16, 2016, this
request was contingent upon ADEQ's approval of APS's August 7, 2012
request for a one-year extension to comply with the MATS. ADEQ's
comments indicate that April 1, 2016 is the appropriate deadline for
this requirement, so we have modified the final compliance deadline
to April 1, 2016.
    \210\ See Cholla Title V Permit (2012), Table C-3: Continuous
Emission Monitors.
    \211\ We used EPA's CEMS Cost Model (available at http://www.epa.gov/ttn/emc/cem.html) to estimate the total annualized cost
of adding inlet CEMS for SO2 and CO2. See
``CEMS Cost Calculation.''
    \212\ APS Comments, Table 3-8. No annualized cost was provided.
---------------------------------------------------------------------------

    Comment: Two commenters requested that EPA implement SCR
installation in three rather than five years. Earthjustice claimed that
the proposed five-year compliance deadline is unreasonable and
inconsistent with the CAA and RHR requirements, noting that compliance
before the ``outside date'' is required whenever earlier compliance is
possible. This commenter contended that average SCR installations have
required 37 to 43 months to implement, and EPA has provided no site-
specific factors for these plants to require a longer-than-average
installation time. The commenter notes that ADEQ has an ``accelerated
permit processing'' program, so that any PSD permits needed to address
sulfuric acid mist increases should not require an extension of the
compliance deadline to five years. The commenter also requested that
EPA obtain and post to the docket the outage schedule for these plants,
which may provide additional justification for a compliance deadline
shorter than five years. In contrast, SRP commented that, if EPA
finalizes a requirement for SCR at Unit 1 ``a five[hyphen]year
compliance period is certainly warranted.'' SRP noted that it estimated
it would require 48 months to install SCR at Coronado Unit 2, and that
installing SCR on Unit 1 would be even more complicated due to the
reduced amount of space following the installation on Unit 2.
    Response: We are finalizing a compliance deadline of five years
from final publication of this notice for all SCR-based emission
limits. As explained in our proposal, five years is a reasonable time
frame for SCR design and installation, particularly where retrofits of
multiple units at a single facility are required. Granting the full
five years for SCR design and installation will allow the facilities to
tie in the SCR systems during routinely scheduled maintenance outages,
which are typically scheduled for every three years. With respect to
Coronado in particular, the five-year compliance schedule will allow
SRP sufficient time to design and install the SCR system on Unit 1 and
to design and install a low-load temperature controller on Unit 2,
which likely must be done in the period after the SCR for Unit 2 is
placed into operation (June 1, 2014).
    Comment: One commenter (Earthjustice) stated that EPA should set
BART limits for PM2.5 and PM10, rather than just
PM10. The commenter indicated that the BART Guidelines
specify that BART should be evaluated and defined for both
PM2.5 and PM10 (citing 40 CFR part 51, Appendix
Y, section II.A.3).
    Response: The BART Guidelines do not require states to set BART
limits for PM2.5 in addition to limits for PM10.
The portions of the BART Guidelines cited by commenters (i.e. sections
II.A.3 and III.A.2) pertain to the identification of sources that are
BART-eligible and sources that are subject-to-BART, not the actual
five-factor analysis or determination of BART for a given source, which
is described in section IV of the Guidelines. With respect to the five-
factor analysis, the Guidelines provide that, ``[m]odeling should be
conducted for SO2, NOX and direct PM emissions
(PM2.5 and/or PM10).'' \213\ The Guidelines thus
provide states with the flexibility to consider either
PM2.5 or PM10 emissions or both, as part of their
five-factor analysis. Likewise, the Guidelines do not require that the
emission limits reflecting BART should include separate limits for
PM2.5 and PM10.\214\ Thus, we are not required by
the RHR to set separate BART limits for PM2.5.
---------------------------------------------------------------------------

    \213\ BART Guidelines, 40 CFR Part 51, Appendix Y, section
IV.D.5.
    \214\ Id. Section V.
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F. Comments on Legal Issues

    Comment: A number of commenters asserted that EPA has acted in a
manner contrary to the CAA, under which states are to play the lead
role in designing and implementing the regional haze program. These
commenters typically indicated that EPA is required to defer to the
states' judgment regarding BART where the state has considered the five
statutory BART factors, and has no authority to override a state's BART
determination simply because it disagrees with the state's conclusions.
The commenters often stated that the states are empowered by the CAA to
determine how best to weigh each of the statutory BART factors and that
EPA's only legal role in SIP review is to determine whether the state's
plan is consistent with the CAA. The commenters generally stated the
belief that ADEQ's BART determinations fully complied with the CAA, the
Regional Haze Rule and the BART Guidelines. The commenters frequently
cited American Corn Growers Ass'n. v. EPA, 291 F.3d (D.C. Cir. 2002);
EME Homer City Generation, L.P. v. EPA, No. 11[hyphen]1302, slip op. at
42 (D.C. Cir. Aug. 21, 2012) (``CSAPR decision''); Luminant Generation
Co. v. EPA, 675 F.3d 917, 921 (5th Cir. 2012); and State of Texas, et
al., v EPA. 690 F.3d 670 (5th Cir. 2012).
    Several commenters stated that EPA made no finding that Arizona
failed to satisfy its statutory obligation to consider and weigh the
BART factors, and asserted that EPA conceded that the state had done so
in its FIP proposal (citing 77 FR 42851). Some commenters (AEPCO, SRP)
stated that EPA proposed to disapprove the SIP, in part, because it is
not consistent with BART decisions that other states have made (citing
77 FR 42836), and contended that this finding is irrelevant to the
approvability of ADEQ's SIP. One commenter (SRP) added that ADEQ's BART
determinations are entirely legal and reasonable and, to the extent
that other states' BART determinations may be relevant, consistent not
only with the action of other states, but with action that EPA has
approved or proposed to approve for those states (i.e., combustion
controls as BART for NOX).
    Two commenters added that EPA purported to defer to ADEQ's BART
determinations by indicating that it would prefer to act on a SIP
revised to address the deficiencies perceived by EPA (citing 77 FR
42839), but the commenters asserted that it is not deference to invite
the State to submit a SIP that conforms to EPA's policy choices. The
commenters contended that in any case, with the court ordered deadline
of November 15, 2012, for EPA to finalize the proposed FIP, it would be
impossible for Arizona to prepare and adopt a revised SIP in time.
    Response: We do not agree that our partial disapproval of the
Arizona Regional Haze SIP is contrary to the CAA. As noted by several
commenters, States have the lead role in determining BART for
individual sources through SIPs. However, EPA also has a crucial role
in reviewing SIPs for compliance with the requirements of the CAA and
its implementing regulations. Pursuant to CAA section 110, States must
submit SIPs to EPA for review and EPA must review SIPs for consistency
with the Act's requirements and disapprove any SIP revision that
``would interfere with any applicable requirement'' of the Act.\215\
The CAA also empowers EPA to call for SIP revisions ``[w]henever [EPA]
finds that the applicable implementation plan for any area is
substantially inadequate to * * * comply with any requirement of this

chapter,'' and impose sanctions when EPA determines they are
``reasonable and appropriate for the purpose of ensuring that the
requirements [of the Act] * * * are met.'' \216\ Furthermore, the Act
mandates that EPA promulgate a FIP when EPA finds that a State has
failed to submit a required SIP to the Agency, failed to submit a
complete SIP, or where EPA disapproves a SIP.\217\ Thus, the CAA
provides EPA with a critical oversight role in ensuring that SIPs meet
the requirements of the CAA.
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    \215\ CAA section 110(a)(1), (k)(3) and (l), 42 U.S.C.
7410(a)(1), (k)(3) and (l).
    \216\ See id. 42 U.S.C. 7410(k)(5), (m).
    \217\ See id. section 7410(c)(1).
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    Nothing in the CAA indicates that EPA's role is less important in
the context of the Regional Haze program than under other CAA programs.
On the contrary, CAA section 110(a)(2)(J) explicitly requires that SIPs
``meet the applicable requirements'' of Part C of Title I of the CAA
including the requirements for visibility protection set forth in
sections 169A and 169B.\218\ Pursuant to section 169A(b), EPA is
required to promulgate visibility protection regulations that apply to
``each applicable implementation plan'' (i.e., each SIP or FIP) \219\
for each State containing one or more Class I areas and each State
``emissions from which may reasonably be anticipated to cause or
contribute to any impairment of visibility in any [Class I area].''
\220\ The CAA specifies that these regulations (including the RHR) must
require each such SIP or FIP to ``contain such emission limits,
schedules of compliance and other measures as may be necessary to make
reasonable progress toward meeting the national goal,'' including
implementation of BART, as determined by the State (or by EPA in the
case of a FIP).\221\ Moreover, the CAA requires that BART for each
``fossil-fuel fired generating power plant having a total generating
capacity in excess of 750 megawatts'' must be determined pursuant to
the guidelines promulgated by EPA (i.e., the BART Guidelines).\222\
Thus, the statute provides EPA a key oversight role in reviewing SIPs
for compliance with the RHR and BART requirements.
---------------------------------------------------------------------------

    \218\ CAA sections 110(a)(2)(J), 169A and 169B 42 U.S.C.
7410(a)(2)(J), 7491 and 7492.
    \219\ Under the CAA, ``applicable implementation plan'' is
defined as ``the portion (or portions) of the implementation plan,
or most recent revision thereof, which has been approved under [CAA
section 110], or promulgated under [CAA section 110](c) * * * and
which implements the relevant requirements of [the CAA].'' CAA
section 302(q), 42 U.S.C. 7602(q). In other words, an ``applicable
implementation plan'' is an EPA-approved SIP or Tribal
Implementation Plan, or an EPA-promulgated FIP.
    \220\ 42 U.S.C. 7491(b)(2). In promulgating the RHR, EPA
determined that ``all States contain sources whose emissions are
reasonably anticipated to contribute to regional haze in a Class I
area and, therefore, must submit regional haze SIPs.'' 64 FR 35720;
see also 40 CFR 51.300(b)(3).
    \221\ 42 U.S.C. 7491(b)(2).
    \222\ Id. In this case, Cholla and Coronado each have a total
generating capacity in excess of 750 megawatts, while Apache has a
total plant-wide generating capacity of 560 megawatts. Thus, the
BART Guidelines are mandatory for BART determinations at Cholla and
Coronado and serve as non-binding guidance with respect to Apache.
---------------------------------------------------------------------------

    The cases cited by commenters do not support an argument that EPA's
role as a reviewer is any less critical in the regional haze context
than it is in reviewing other SIP components. In American Corn Growers
v. EPA, the petitioners challenged the original RHR because, among
other things, the RHR treated one of the five statutory factors
differently than the others by requiring States to consider the degree
of visibility improvement from imposing BART on a group of sources
rather than on a source-specific basis.\223\ The court concluded that
such a requirement could force States to apply BART controls at sources
without evidence that the individual sources contributed to visibility
impairment at a Class I area, which encroached on States' primary
authority under the regional haze provisions to determine which
individual sources are subject to BART and what BART controls are
appropriate for each source.\224\ Therefore, the court vacated the
visibility improvement part of the original RHR as contrary to the
statute.\225\ Contrary to some commenters' suggestions, however, the
American Corn Growers decision did not address EPA's authority to
reject a State's BART determinations for failure to conform to the CAA,
the RHR or the BART Guidelines.
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    \223\ 291 F.3d at 5-9.
    \224\ Id. at 7-8.
    \225\ EPA revised the RHR to address the court's decision in
American Corn Growers at the same time as we promulgated the BART
Guidelines. 70 FR 39104 (July 6, 2005). The revised RHR and the
Guidelines were upheld by the D.C. Circuit in Utility Air Regulatory
Group v. EPA, 471 F.3d 1333 (D.C. Cir. 2006).
---------------------------------------------------------------------------

    Commenters also cite Luminant Generation v. EPA, 675 F.3d 917, 921
(5th Cir. 2012) and Texas v. EPA, 690 F.3d 670 (5th Cir. 2012). Neither
of these cases involves BART or the CAA's regional haze provisions at
all. Rather, they involved EPA's disapprovals of SIP revisions
involving Texas's minor new source review (NSR) program. As noted by
the Luminant court, ``because `the Act includes no specifics regarding
the structure or functioning of minor NSR programs' and because the
implementing regulations are `very general [,] * * * SIP-approved minor
NSR programs can vary quite widely from State to State.''' \226\ By
contrast, Regional Haze SIPs and BART determinations are subject to
detailed requirements set forth in CAA sections 169A, the RHR and the
BART Guidelines. While in Luminant and Texas, the Fifth Circuit found
that EPA had failed to tie its disapproval to any requirement of the
CAA or EPA's implementing regulations,\227\ in this case our
disapproval is based on the SIP's failure to comply with CAA sections
110(a)(2) and 169A(b)(2)(A), as implemented through the RHR and the
BART Guidelines.
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    \226\ 675 F.3d at 922 (citing 74 FR 51418, 51421 (Oct. 6, 2009).
    \227\ 675 F.3d at 924, 929; 690 F.3d at 679, 682, 686.
---------------------------------------------------------------------------

    As noted above, CAA section 110(a)(2)(J) requires all SIPs to
``meet the applicable requirements'' of Part C of Title I of the CAA,
including the requirement that each source found subject-to-BART,
``procure, install, and operate, as expeditiously as practicable (and
maintain thereafter) the best available retrofit technology * * *''
\228\ Section 169A(g)(2) further provides that:
---------------------------------------------------------------------------

    \228\ CAA section 169A(b)(2)(A)., 42 U.S.C. 7491(b)(2)(A).

    In determining best available retrofit technology the State (or
the Administrator in determining emission limitations which reflect
such technology) shall take into consideration the costs of
compliance, the energy and nonair quality environmental impacts of
compliance, any existing pollution control technology in use at the
source, the remaining useful life of the source, and the degree of
improvement in visibility which may reasonably be anticipated to
result from the use of such technology.\229\
---------------------------------------------------------------------------

    \229\ 42 U.S.C. 7491(g)(2).

---------------------------------------------------------------------------
Similarly, the RHR provides that:

    The determination of BART must be based on an analysis of the
best system of continuous emission control technology available and
associated emission reductions achievable for each BART-eligible
source that is subject to BART within the State. In this analysis,
the State must take into consideration the technology available, the
costs of compliance, the energy and nonair quality environmental
impacts of compliance, any pollution control equipment in use at the
source, the remaining useful life of the source, and the degree of
improvement in visibility which may reasonably be anticipated to
result from the use of such technology.\230\
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    \230\ 40 CFR 51.308(e)(1)(ii)(A).

ADEQ's BART determinations for NOX at Apache Units 2 and 3,
Cholla Units 2, 3 and 4 and Coronado Units 1 and 2 fall short of these
requirements in several respects.
    First, ADEQ did not analyze the ``best system of continuous
emission control

technology available and associated emission reductions achievable.''
Rather it accepted the source's own assertions about what emissions
reductions were achievable with various control technologies. For
example, in response to comments from the FLMs arguing that SCR could
achieve lower rates on 30-day-rolling average, ADEQ stated that:

    ADEQ's BART evaluations were based on site-specific information
provided by the applicants. It is the Department's understanding
that such information was based partially on feedback received from
vendors and plant personnel who are intimately familiar with the
specific equipment that is being considered. In that regard, the
Department based its BART computations on the emission rates
proposed by the applicant for the different control technology
options.\231\
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    \231\ Arizona Regional Haze SIP, Appendix E, ``Responsiveness
Summary'' at 13.

While it is certainly reasonable to consider site-specific information
provided by the sources as part of a BART analysis, it is not
reasonable to assume, with no independent analysis, that the sources
have appropriately identified the emissions reductions achievable with
the best available controls. ADEQ provided no evidence that the
sources' estimates were based on legitimate site-specific
considerations or that ADEQ undertook any verification of these
estimates. Therefore, ADEQ has not demonstrated that its BART
determinations were ``based on an analysis of the best system of
continuous emission control technology available and associated
emission reductions achievable.''
    Second, ADEQ has not demonstrated that it actually took into
consideration the BART factors in making its determinations. In
particular, while ADEQ provided information regarding each of the
factors, it gave no explanation or rationale for how it reached a
determination based on that information.
    Finally, ADEQ did not appropriately consider the ``degree of
improvement in visibility which may reasonably be anticipated'' from
installation of BART because it did not consider visibility benefits at
all of the affected Class I areas, nor did it consider the total
visibility benefit expected to result from the entire BART-eligible
source. Overlooking significant visibility benefits at additional areas
and from multiple BART-eligible units considerably understates the
overall benefit of controls to improve visibility and is contrary to
the very purpose of BART, i.e., ``eliminating or reducing'' visibility
impairment at all Class I areas.\232\ Thus ADEQ's BART determinations
for NOX at Apache Units 2 and 3, Cholla Units 2, 3 and 4 and
Coronado Units 1 and 2 do not meet the requirements of CAA section
169A(g)(2) or 40 CFR 51.308(e)(1)(ii)(A).
---------------------------------------------------------------------------

    \232\ CAA section 169A(b)(2)(A).
---------------------------------------------------------------------------

    In addition, 40 CFR 51.308(e)(1)(ii)(B) provides that:

    The determination of BART for fossil-fuel fired power plants
having a total generating capacity greater than 750 megawatts must
be made pursuant to the guidelines in appendix Y of this part
(Guidelines for BART Determinations under the Regional Haze Rule).

Cholla and Coronado each have a generating capacity greater than 750
megawatts. Therefore, the BART determinations for these BART sources
must be made pursuant to the BART Guidelines. However, ADEQ's BART
determinations for these sources did not fully comply with the BART
Guidelines. In particular, as explained more fully above, contrary to
the Guidelines' direction that ``cost estimates should be based on the
OAQPS Control Cost Manual, where possible,'' the control cost
calculations supplied by the utilities and relied upon by ADEQ included
line item costs not allowed by the Control Cost Manual, such as owner's
costs, surcharge, and AFUDC. Thus, ADEQ's consideration of the ``cost
of compliance'' for these units was not consistent with the Guidelines.
Furthermore, as explained above, ADEQ's consideration of visibility
benefits was inconsistent with the Guidelines because the State did not
consider benefits at multiple Class I areas and multiple BART-eligible
units at each source. In addition, ADEQ failed to provide ``a
justification for adopting the technology [the State selected] as the
`best' level of control, including an explanation of the CAA factors
that led [the State] to choose that option over other control levels.''
\233\ Therefore, ADEQ's BART determinations for NOX at
Cholla and Coronado do not comply with 40 CFR 51.308(e)(1)(ii)(B).
---------------------------------------------------------------------------

    \233\ BART Guidelines, 40 CFR Part 51, Appendix Y, section
IV.E.2.
---------------------------------------------------------------------------

    Finally, for all pollutants at all units covered by today's action,
ADEQ's Regional Haze SIP does not meet the requirements of 40 CFR
51.308(e)(1)(iii) and (iv) because it lacks the following elements:

     A requirement that each source subject to BART be
required to install and operate BART as expeditiously as
practicable, but in no event later than 5 years after approval of
the implementation plan revision.
     A requirement that each source subject to BART maintain
the control equipment required by this subpart and establish
procedures to ensure such equipment is properly operated and
maintained.

These two requirements are mandatory elements of the RHR and are
necessary to ensure that BART is procured, installed and operated, as
expeditiously as practicable and maintained thereafter, as required
under CAA section 169A(b)(2)(A). Moreover, CAA section 110(a)(2)
requires that emissions limits such as BART be ``enforceable'' and
section 302(k) requires emissions limits to be met on a continuous
basis. Arizona's Regional Haze SIP lacks requirements for monitoring,
recordkeeping and reporting sufficient to ensure that the BART limits
are enforceable and are met on a continuous basis.
    Therefore, Arizona's BART determinations for Apache, Cholla and
Coronado do not meet several requirements of the CAA, the RHR and the
BART Guidelines. Accordingly, we are compelled to partially disapprove
Arizona's Regional Haze SIP.
    Finally, several commenters cited EME Homer City Generation v. EPA,
No. 11-1302 (D.C. Cir. Aug. 21, 2012). In EME Homer City Generation,
the D.C. Circuit vacated EPA's ``Transport Rule'' (also known as the
``Cross-State Air Pollution Rule'' or ``CSAPR''), which was promulgated
by EPA to address interstate transport of SO2 and
NOX under CAA section 110(a)(2)(D). The court found that the
Transport Rule exceeded EPA's authority under section 110(a)(2)(D)
because the rule had the potential to require upwind States to reduce
emissions by more than their own significant contributions to downwind
nonattainment and because EPA had not given states an opportunity to
submit SIPs after it quantified their obligations for emissions
reductions to address transport. Commenters here point to the D.C.
Circuit's statements concerning state and federal roles under the CAA
and argue that EPA has exceeded its statutorily mandated role in
proposing to disapprove portions of Arizona's Regional Haze SIP and
promulgate a FIP.
    While we agree that the general principles concerning state and
federal roles under Title I of the CAA apply to our action here, we do
not agree that our action here is inconsistent with those principles.
In this action, we are fulfilling our statutory duty to review
Arizona's Regional Haze SIP, including its BART determinations, for
compliance with the applicable requirements of the CAA and the RHR, and
to disapprove any portions of the

plan that do not meet those requirements. Based on our review of the
SIP, we proposed to determine that certain elements of Arizona's
Regional Haze SIP did meet the requirements of the CAA and the RHR, and
we proposed to approve those elements. However, for the reasons
explained in detail in our proposal and elsewhere in this document, we
have concluded that Arizona's BART determinations for NOX at
several units did not comply with the requirements of the CAA and the
RHR. Based on these findings, we are required to disapprove these
portions of Arizona's Regional Haze SIP.
    In some instances, we expressed our findings of non-compliance with
the relevant requirements in terms of ``disagreement'' with the state's
analysis. These statements were not intended to suggest that our
proposed partial disapproval was simply based on policy disagreements
with the state. Rather we used the term ``disagree'' as a short hand
for our findings that specific elements of Arizona's analyses did not
meet the requirements of the CAA and the RHR. For example, we noted
that, ``[w]e disagree with several aspects of the NOX BART
analysis for Apache Units 2 and 3.'' \234\ We then went on to list the
specific deficiencies in the state's analysis, and concluded that ``we
are proposing to disapprove ADEQ's BART determination for
NOX at Apache Units 2 and 3, since it does not comply with
40 CFR 51.308(e)(1)(ii)(A).'' \235\ We made similar findings with
respect to ADEQ's BART determination for NOX at Cholla Units
2, 3 and 4 and Coronado Units 1 and 2.\236\ We have also described in
detail, both in our proposal and in this document, the other aspects of
the state's BART determinations that do not comply with the CAA and the
RHR.
---------------------------------------------------------------------------

    \234\ 77 FR 42846.
    \235\ Id.
    \236\ 77 FR 42849, 42851.
---------------------------------------------------------------------------

    Finally, some commenters appear to have misunderstood our statement
that ADEQ's ``NOX BART determinations for the coal-fired
units are neither consistent with the requirements of the Act nor with
BART decisions that other states have made.'' As noted by several
commenters, the CAA and the RHR provide states with considerable
discretion in deciding how to weigh the statutory factors as a part of
a BART analysis. However, this discretion must be reasonably exercised
in compliance with the applicable requirements. Consistency with other
EPA-approved BART determinations is one marker of reasonableness, as
well as compliance with the requirements of the RHR. Such consistency
is particularly relevant for BART determinations at fossil-fuel fired
power plants having a capacity in excess of 750 megawatts, which must
be made pursuant to the BART Guidelines.\237\ To the extent a BART
determination for such a power plant is plainly inconsistent with EPA-
approved determinations for similar sources, it is more likely to be
inconsistent with the RHR and the BART Guidelines and therefore to
warrant greater scrutiny for compliance with the applicable
requirements.
---------------------------------------------------------------------------

    \237\ CAA section 169A(b) and 40 CFR 51.308(e)(1)(ii)(B).
---------------------------------------------------------------------------

    Comment: Several commenters (ACCCE, ADEQ, APS, SRP) asserted that
it is contrary to the CAA for EPA to propose action on only the
portions of ADEQ's SIP that address the three power plants that are the
subject of the proposed FIP. One commenter (APS) stated that EPA may
not ignore all other sources of visibility-impairing pollutants in the
state (nor may it ignore the other categories of visibility-impairing
pollutants by focusing only on nitrates, sulfates and PM) and establish
BART limitations for the three affected power plants outside the
context of the long-term strategy and larger reasonable progress
requirements of the regional haze program. Commenters ACCCE, ADEQ and
SRP contended that CAA section 110(k)(3) requires EPA either to approve
a SIP submittal ``as a whole'' or to approve that SIP submittal in part
and disapprove it in part in a single rulemaking that addresses in its
entirety ``the plan revision.'' The commenters indicated that this
requirement of the CAA is sensible because it is the plan as a whole,
with all its elements working together, that must ensure that the CAA's
regional haze[hyphen]related goals are being reached; any other
approach to SIP review and approval would fail to take into account the
full array of regulatory choices that Arizona has made to address
regional haze.
    Response: We do not agree that we are required to act on Arizona's
Regional Haze SIP as a whole. As noted by some commenters, our action
on Arizona's Regional Haze SIP is governed by inter alia, CAA section
110(k)(3), which provides that in the case of any submittal on which
the Administrator is required to act under section 110(k)(2), the
Administrator shall approve such submittal as a whole if it meets all
of the applicable requirements of this chapter. If a portion of the
plan revision meets all the applicable requirements of this chapter,
the Administrator may approve the plan revision in part and disapprove
the plan revision in part. The plan revision shall not be treated as
meeting the requirements of this chapter until the Administrator
approves the entire plan revision as complying with the applicable
requirements of this chapter.\238\
---------------------------------------------------------------------------

    \238\ 42 U.S.C. 7410(k)(3).
---------------------------------------------------------------------------

    Some commenters have read this provision as requiring that EPA act
on Arizona's Regional Haze SIP as a whole. We disagree that this
language addresses the question of whether EPA may consider different
elements of a State's plan in separate notice and comment rulemakings.
However, even assuming that this provision of the Clean Air Act did
limit EPA's ability to act sequentially on portions of a SIP
submission, the requirement to act on a submittal ``as a whole''
applies only if the submittal meets all of the applicable requirements
of the CAA. As explained in our proposal and elsewhere in this
document, we have determined that the Arizona Regional Haze SIP does
not meet all of the applicable requirements of the CAA. Specifically,
we have determined that the submittal as a whole does not meet the
requirements of CAA section 169A(b)(2)(A), as implemented through the
RHR and the BART Guidelines. Under these circumstances, we are clearly
not obligated to act on the plan as a whole, but are given discretion
to act on distinct portions of the plan.\239\
---------------------------------------------------------------------------

    \239\ See Hall v. EPA, 273 F.3d 1146, 1159 (9th Cir. 2001)
(section 110(k)(3) ``permits the EPA to issue `partial approvals,'
that is, to approve the States' SIP revisions in piecemeal
fashion'').
---------------------------------------------------------------------------

    While we agree that, as a matter of policy, it is generally
preferable to act on plan submissions as a whole, we are currently
subject to a court-ordered deadline of November 15, 2012 to act on the
BART determinations for Apache Generating Station, Cholla Power Plant
and Coronado Generating Station.\240\ Although these BART
determinations are part of the overall Regional Haze plan for Arizona,
they are also severable from that plan, since BART determinations are
made on a source-by-source basis and are not dependent upon other
elements of the plan.\241\

Therefore, we are taking action on these BART determinations first and
we will act on the remainder of the Arizona Regional plan in accordance
with the court-ordered deadlines for that action.
---------------------------------------------------------------------------

    \240\ EPA agreed to this deadline after concluding that
litigation would most likely result in a shorter schedule than that
to which Plaintiffs had agreed in negotiation. See Sierra Club v.
Johnson, 444 F.Supp.2d 46, 58 (D.D.C. 2006) (``this case devolves to
a single issue: whether defendant has met the `heavy burden' of
demonstrating that it would be impossible to comply with plaintiff's
proposed * * *'').
    \241\ See 40 CFR 51.308(e)(1)(ii)(A)(``[t]he determination of
BART must be based on an analysis of the best system of continuous
emission control technology available and associated emission
reductions achievable for each BART-eligible source that is subject
to BART within the State.''
---------------------------------------------------------------------------

    Comment: One commenter (ADEQ) asserts that EPA does not have the
authority to adopt a FIP because none of the three triggering events
for a FIP under CAA section 110(c)(1) has occurred. Specifically, the
commenter states that:

* * * for EPA to have authority to promulgate a regional haze FIP in
Arizona, one of three events must have occurred: (1) a finding of
failure to submit a regional haze SIP, (2) a finding of failure to
satisfy the minimum criteria for a complete regional haze SIP under
section 110(k)(1)(A) or (3) disapproval of a regional haze SIP
submitted by Arizona. None of these three events has occurred.

With respect to EPA's January 2009 finding of failure to submit, the
commenter argues that:

    Section 110(c)(1) * * * does not allow EPA to treat the omission
of elements from a SIP submission as a failure to submit a SIP.
Section 110(c)(1) is quite specific. If EPA believes SIP omissions
render a SIP incomplete, the agency may make a finding under section
110(k)(1)(A) within the time period required by section 110(k)(1)(B)
and start the FIP clock under the second clause of section
110(c)(1)(A). If EPA cannot make such a finding or, as in this case,
fails to do so, the agency may disapprove the SIP, and start the FIP
clock under section 110(c)(1)(B). By treating the alleged omission
of elements from a SIP as the failure to make a required submission
under the first clause of section 110(c)(1)(A), EPA is circumventing
these procedures.

The commenter adds that if EPA did have the authority to promulgate a
regional haze FIP, it would only have the authority to address those
elements of the SIP that EPA identified as having not been submitted,
and EPA has never found that Arizona failed to submit a SIP
establishing BART.
    Response: We do not agree that we lack authority to issue a FIP
addressing BART requirements for the three sources covered by today's
action. The commenter's arguments in this regard appear to be based on
a misunderstanding of the requirements of the CAA and the RHR in
relation to Arizona's Regional Haze submittals.
    EPA promulgated the original RHR in 1999.\242\ As relevant here,
section 308 of the RHR requires states to submit SIPs that establish
reasonable progress goals and long-term strategies for achieving those
goals and provide for implementation of BART.\243\ In addition to the
general requirements of section 308, EPA also adopted specific
provisions that gave a handful of states, including Arizona, the option
of submitting a regional haze SIP based on the recommendations of the
Grand Canyon Visibility Transport Commission (GCVTC). Under the RHR, a
SIP approved by EPA as meeting all of the requirements of section 309
would be ``deemed to comply with the requirements for reasonable
progress with respect to the 16 Class I areas [on the Colorado Plateau]
for the period from approval of the plan through 2018.'' \244\
    Arizona made two submittals under section 309 in 2003 and 2004, but
never submitted a complete 309 SIP.\245\ Rather, on December 24, 2008,
ADEQ sent a letter to EPA re-submitting its prior 309 SIP submissions
and acknowledging that the submittal did not include provisions to
address the requirements of 309(d)(4) or 309(g).\246\ These were not
minor omissions: 309(d)(4) required the submission of ``better than
BART'' milestones and a trading program for SO2, as well as
BART requirements for stationary source PM and NOX
emissions, and 309(g) required implementation of any additional
measures necessary to demonstrate reasonable progress for the
additional Class I areas, in compliance with the provisions of Sec.
51.308(d)(1) through (4).\247\ Thus, as of 2008, ADEQ's Regional Haze
SIP, by its own admission, did not include provisions addressing BART
(or for an alternative to BART) for NOX, PM or
SO2. On January 15, 2009 EPA found that 37 states, including
Arizona, had failed to make all or part of the required SIP submissions
to address regional haze.\248\ We explained that:
---------------------------------------------------------------------------

    \245\ We have included a more detailed history of Arizona's
submissions under 309 in the docket for this action (Docket No. EPA-
R09-OAR-2012-0021).
    \246\ Letter from Stephen A. Owens, ADEQ, to Wayne Nastri, EPA
(Dec. 14, 2008).
    \247\ 40 CFR 51.309(d)(4)(i) and (vii), (g)(2).
    \248\ 74 FR 2392.

    This finding starts the two year clock for the promulgation by
EPA of a FIP. EPA is not required to promulgate a FIP if the state
makes the required SIP submittal and EPA takes final action to
approve the submittal within two years of EPA's finding.\249\
---------------------------------------------------------------------------

    \249\ Id. at 2393

Under the CAA, any party seeking judicial review of EPA's finding of
failure to submit (``2009 Finding'') was required to file a petition
for review with the appropriate United States Circuit Court of Appeals
within 60 days of publication of the Finding in the Federal
Register.\250\ No party filed such a petition.
---------------------------------------------------------------------------

    \250\ CAA section 307(b). 42 U.S.C. 7607(b).
---------------------------------------------------------------------------

    At the time of the 2009 Finding, EPA anticipated that ADEQ would
submit a SIP revision covering 309(d)(4) and 309(g), which would enable
EPA to fully approve ADEQ's 309 SIP as meeting all of the requirements
of the Regional Haze Rule, thus ending the FIP clock. However, ADEQ did
not submit a 309 SIP revision to address these two elements, but
instead decided to develop a 308 SIP, which it submitted to EPA in
February 2011.
    In January 2011, EPA received a notice of intent to sue covering
dozens of states, including Arizona, stating that we had not met the
statutory deadline for promulgating Regional Haze FIPs and/or approving
Regional Haze SIPs. This notice was followed by a lawsuit filed by
several advocacy groups (Plaintiffs) in August 2011.\251\ In order to
resolve this lawsuit and avoid litigation, EPA entered into a Consent
Decree with the Plaintiffs, which sets deadlines for action for all of
the states covered by the lawsuit, including Arizona. This decree was
entered and later amended by the Federal District Court for the
District of Columbia over the opposition of Arizona.\252\
---------------------------------------------------------------------------

    \251\ National Parks Conservation Association v. Jackson (D.D.C.
Case 1:11-cv-01548).
    \252\ National Parks Conservation Association v. Jackson (D.D.C.
Case 1:11-cv-01548), Memorandum Order and Opinion (May 25, 2012) and
Minute Order (July 2, 2012).
---------------------------------------------------------------------------

    In opposing the entry of the consent decree, Arizona argued that
the 2009 Finding did not give EPA authority to promulgate a Regional
Haze FIP for Arizona. The court rejected this argument, explaining
that:

    Arizona contends that the Finding did not constitute a
disapproval of the SIPs that had previously been submitted because
it only notes that Arizona did not submit two of Section 309's
required elements. Ariz. Opp. [Dkt.  24] at 6. The Court
does not read the 2009 Finding so narrowly. In the Court's view, the
2009 Finding reaches a conclusion that Arizona `has failed to make a
required submission or finds that the plan or plan revision
submitted by the State does not satisfy the minimum criteria.' 42
U.S.C. 7410(c)(1). Under the CAA, this triggers the EPA's statutory
obligation to promulgate a FIP.\253\
---------------------------------------------------------------------------

    \253\ See NPCA v. EPA, (D.D.C. Case 1:11-cv-01548). Dkt
 35, at 3, n. 1.

Under the terms of the Consent Decree, as amended, EPA is currently
subject to two sets of deadlines for taking action on Arizona's
---------------------------------------------------------------------------
Regional Haze SIP. Specifically, the CD requires that:

    By the ``Proposed Promulgation Deadlines'' set forth in Table A
below EPA shall sign a notice(s) of proposed rulemaking in which it

proposes approval of a SIP, promulgation of a FIP, partial approval
of a SIP and promulgation of a partial FIP, or approval of a SIP or
promulgation of a FIP in the alternative, for each State therein,
that collectively meet the regional haze implementation plan
requirements that were due by December 17, 2007 under EPA's regional
haze regulations.
    By the ``Final Promulgation Deadlines'' set forth in Table A
below, EPA shall sign a notice(s) of final rulemaking promulgating a
FIP for each State therein to meet the regional haze implementation
plan requirements that were due by December 17, 2007 under EPA's
regional haze regulations, except where, by such deadline EPA has
for a State therein signed a notice of final rulemaking
unconditionally approving a SIP, or promulgating a partial FIP and
unconditional approval of a portion of a SIP, that collectively meet
the regional haze implementation plan requirements that were due by
December 17, 2007 under EPA's regional haze regulations.

Table A, as revised, sets a proposal deadline for BART determinations
for Apache Generating Station, Cholla Power Plant and Coronado
Generating Station of July 2, 2012 and the final action deadline for
these three BART determinations of November 15, 2012. The deadline for
EPA to propose action on the remainder of the Arizona Regional Haze SIP
is December 8, 2012, and the deadline for final action is July 15,
2013.\254\
---------------------------------------------------------------------------

    \254\ On November 13, 2012, the D.C. District Court granted a
motion by EPA to modify the Consent Decree to extend the deadlines
for promulgation of a FIP for any remaining elements of the SIP that
are disapproved. Under the revised deadlines, EPA will propose any
necessary FIP elements by March 8, 2013, and finalize such elements
by October 15, 2013.
---------------------------------------------------------------------------

    Thus, pursuant to CAA section 110(c)(1) and the court's orders
entering and amending the Consent Decree, we are not only authorized,
but are required to issue a FIP for any portion of the Arizona SIP that
we cannot approve. For the reasons stated in our proposal and elsewhere
in this document, we have determined that we cannot approve the state's
BART determinations for NOX at Apache, Cholla and Coronado,
nor can we approve the compliance-related requirements that were
omitted from the Arizona Regional Haze SIP. Therefore, we are obligated
to promulgate a FIP to address these requirements.
    Comment: Several commenters (AUG, EEI, PacifiCorp, SRP) stated that
EPA cannot propose or finalize a NOX BART FIP for these
Arizona plants until it has taken final action (following notice-and-
comment rulemaking) on ADEQ's Regional Haze SIP. According to the
commenters, EPA's authority to propose and then take final action to
promulgate a FIP comes into existence only when a state has not
submitted a SIP or when EPA has made a final determination that a
submitted SIP is not approvable (citing Train v. NRDC, 421 U.S. 60, 79
(1975)). The commenters believe this principle is confirmed by CAA
sections 307(d)(1)(B), (3) and (6) because EPA cannot present the
relevant factual, legal, and policy information and rationale necessary
to justify a proposed or final FIP rule until it has properly taken
final action on any relevant SIP before it.
    One commenter (EEI) also states that EPA's assertion that it was
compelled to propose a FIP at the same time that it disapproved a
portion of the Arizona SIP, due to a two-year FIP clock that started
with EPA's 2009 Finding of Failure to Submit, is inconsistent with the
CSAPR decision. The commenter stated that EPA did not provide
sufficient notice of the problems with the SIP to enable Arizona to
remedy them, which is precisely the same problem identified by the
CSAPR court. The commenter adds that EPA must provide the state a
realistic opportunity to avoid being pulled into a FIP. Given that EPA
has consent decree obligations to finalize BART requirements for the
EGUs addressed by the proposed SIP by November 15, 2012, and EPA did
not propose disapproval of the SIP until July 20, 2012, a reasonable
opportunity to develop and receive approval of a revised SIP was not
offered to the state.
    Response: We do not agree that we are required to take final action
on Arizona's Regional Haze SIP before promulgating a FIP. Commenters'
arguments to this effect appear to conflate the procedural requirements
for EPA's issuance of a FIP with procedural requirements for action on
a SIP. In fact, these are two actions are governed by different
provisions of the CAA.
    As explained in the previous response, EPA's 2009 finding that
Arizona failed to submit a complete Regional Haze SIP triggered a ``FIP
clock'' under CAA section 110(c).\255\ This FIP clock could only have
been stopped if Arizona had submitted, and EPA had fully approved a
Regional Haze SIP, before January 15, 2011. Neither of these two things
occurred. Therefore, EPA remains subject to this ``FIP duty.'' Our
action today fulfills part of that duty.
---------------------------------------------------------------------------

    \255\ 42 U.S.C. 7410(c). See also Train, 421 U.S. at 64, 79
(explaining that the 1970 CAA Amendments ``sharply increased federal
authority and responsibility in the continuing effort to combat air
pollution,'' including giving EPA authority to devise a FIP if the
State's plan fails to satisfy the standards of section 7410(a)(2)).
---------------------------------------------------------------------------

    As several commenters noted, Arizona submitted a Regional Haze SIP
on February 28, 2011, and the SIP was deemed complete by operation of
law on August 28, 2011, pursuant to CAA section 110(k)(1)(B).\256\
This, in turn, triggered a deadline of August 28, 2012, for us to take
final action on the SIP, pursuant to CAA section 110(k)(1)(B).\257\ We
acknowledge that this deadline has now passed and we intend to act as
quickly as possible to fulfill our duty to act on those portions of the
SIP not addressed in today's action. However, the fact that we have not
acted on the entirety of the SIP submittal does not remove or otherwise
alter our legal obligation to promulgate a FIP under CAA section
110(c). Our FIP duty does not terminate until we have actually approved
the submitted SIP. As explained in our NPRM, TSD and elsewhere in this
document, we cannot approve the State's BART determinations for
NOX at Apache, Cholla and Coronado, nor can we approve the
compliance-related requirements that were omitted from the Arizona
Regional Haze SIP. Therefore, we are obligated to promulgate a FIP to
address these requirements, and we are doing so in today's action.
---------------------------------------------------------------------------

    \256\ 42 U.S.C. 7410(k)(1)(B).
    \257\ 42 U.S.C. 7410(k)(2).
---------------------------------------------------------------------------

    Furthermore, while we agree that the procedural requirements for
promulgation of a FIP under 110(c) are set forth in CAA section
307(d),\258\ we do not agree that our action violates that provision in
any way. Consistent with the requirements of that section, our proposal
included a summary of the factual data on which our proposed FIP was
based, as well as the methodology used in obtaining the data and in
analyzing the data and the major legal interpretations and policy
considerations underlying the proposed FIP.\259\ In addition, we
provided a detailed evaluation of Arizona's BART analyses for the
relevant units, which formed the basis for our proposed action on those
portions of the Arizona Regional Haze SIP.\260\ This final rulemaking
includes similar information with respect to the SIP and the FIP, as
well as ``an explanation of the reasons for any major changes in the
promulgated rule from the proposed rule'' and ``a response to each of
the

significant comments, criticisms, and new data submitted in written or
oral presentations during the comment period.'' \261\ Therefore, our
action complies with the applicable procedural requirements of the CAA.
---------------------------------------------------------------------------

    \258\ See CAA section 307(d)(1)(B), 42 U.S.C. 7607(d)(1)(B),
(``This subsection applies to * * * the promulgation or revision of
an implementation plan by the Administrator under [CAA section
110](c)'']
    \259\ See CAA section 307(d)(3), 42 U.S.C. 7607(d)(3).
    \260\ The SIP portion of our action is subject to the procedural
requirements of section 553(b) of Administrative Procedure Act
(APA), 5 U.S.C. 553(b), rather than the requirements of CAA
subsection 307(d), 42 U.S.C. 7607(d).
    \261\ CAA section 307(d)(6)(A) & (B), 42 U.S.C. 7607(d)(6)(A) &
(B).
---------------------------------------------------------------------------

    Finally, we do not agree with commenters' assertions that the D.C.
Circuit's decision in EME Homer City Generation precludes us from
promulgating a partial FIP concurrently with our partial disapproval of
Arizona's Regional Haze SIP. In EME Homer City Generation, the court
found that EPA had acted improperly in issuing the Transport Rule
because we simultaneously defined states' ``good neighbor obligations''
under CAA section 110(a)(2)(D)(i)(I) and issued FIPs to address those
obligations.\262\ The court explained that:
---------------------------------------------------------------------------

    \262\ EME Homer City Generation, slip op. at 7.

* * * the triggers for a FIP are EPA's finding that the SIP fails to
contain a ``required submission'' or EPA's disapproving a SIP
because of a ``deficiency.'' But logically, a SIP cannot be deemed
to lack a required submission or be deemed deficient for failing to
implement the good neighbor obligation until after EPA has defined
the State's good neighbor obligation. Once it defines the
obligation, then States may be forced to revise SIPs under Section
110(k)(5) or to submit new SIPs under Section 110(a)(1). Only if
that revised or new SIP is properly deemed to lack a required
submission or is properly deemed deficient may EPA resort to a FIP
for the State's good neighbor obligation.\263\
---------------------------------------------------------------------------

    \263\ Id. at 46.

In essence, the D.C. Circuit found that EPA's findings of failure to
submit and disapprovals of state transport SIPs did not trigger FIP
obligations under CAA section 110(c) because these actions occurred
``before [EPA] told the States what emissions reductions their SIPs
were supposed to achieve under the good neighbor provision.'' \264\
---------------------------------------------------------------------------

    \264\ Id. at 47 (emphasis in original).
---------------------------------------------------------------------------

    In this case, by contrast, EPA defined states' obligations under
the RHR and the BART Guidelines well in advance of its findings of
failure to submit and subsequent SIP disapprovals. EPA promulgated the
original RHR on July 1, 1999.\265\ Following the D.C. Circuit's
decision in American Corn Growers, EPA revised the RHR and issued the
final BART Guidelines on July 6, 2005.\266\ The revised RHR and the
Guidelines were upheld by the DC Circuit in Utility Air Regulatory
Group v. EPA, 471 F.3d 1333 (D.C. Cir. 2006).\267\ As explained in our
proposal and elsewhere in this document, the BART Guidelines provide
detailed instructions to states on how to determine which sources are
subject to BART and how to analyze the five statutory factors in order
to set emissions limits representing BART for each subject-to-BART
source.\268\ In 2006, responding to specific questions from various
States and Regional Planning Organizations (RPOs), EPA issued further
guidance to help States implement the RHR and BART Guidelines.\269\
---------------------------------------------------------------------------

    \265\ 64 FR 35714.
    \266\ 70 FR 39104. This finding covered 37 states, the District
of Columbia and the Virgin Islands.
    \267\ In response to another D.C. Circuit decision, Center for
Energy and Economic Development v. EPA, 398 F.3d 653 (D.C. Cir.
2005), EPA revised the RHR's provisions governing alternatives to
source-specific BART determinations on October 13, 2006. These
revisions did not alter the requirements for source-specific BART
determinations that apply to Arizona's BART determinations at issue
here.
    \268\ 40 CFR Part 51, Appendix Y. While the Guidelines are only
mandatory for fossil fuel-fired electric generating plants with a
total generating capacity in excess of 750 megawatts, States are
encouraged to follow the BART Guidelines in making BART
determinations for other types of sources. Id. section I.H. The
Guidelines also set specific presumptive limits for SO2
and NOX for these large power plants, but allow states to
apply more or less stringent limits based upon source-specific five-
factor analyses. 70 FR 39131-39132.
    \269\ Memo from Joseph W. Paise Regarding Regional Haze
Regulations and Guidelines for BART (July 19, 2006); Additional
Regional Haze Questions (Guidance) (Sept. 27 2006). In addition, EPA
issued final ``Guidance for Setting Reasonable Progress Goals Under
the Regional Haze Program'' on June 1, 2007, but this Guidance is
not directly relevant for individual BART determinations.
---------------------------------------------------------------------------

    As noted in prior responses, EPA issued a finding of failure to
submit for Regional Haze SIPs on January 15, 2009, thus triggering a
FIP clock under CAA section 110(c).\270\ By this time, states had
already had more than three years since issuance of the final BART
Guidelines (and more than two years since the final revisions to the
RHR and the issuance of further guidance on the RHR and BART) to
develop their Regional Haze SIPs. By the time the FIP clock actually
ran out in January 2011, EPA had received Regional Haze SIPs from
nearly every state. EPA has since proposed to approve, in part or in
whole, the vast majority of these SIPs.\271\ We have also has taken
final action to approve, in part or in whole, many of these SIPs.\272\
This stands in contrast to the situation in EME Homer City Generation,
where, the court noted that, ``every Transport Rule State that
submitted a good neighbor SIP for the 2006 24-hour PM2.5
NAAQS was disapproved.'' \273\ Thus, it is clear that states had ample
opportunity to submit approvable Regional Haze SIPs before EPA was
obligated to promulgate Regional Haze FIPs under CAA section 110(c).
---------------------------------------------------------------------------

    \270\ 74 FR 2392.
    \271\ See, e.g., 76 FR 36450 (Nevada); 77 FR 24794 (New York);
76 FR 13944 (California); 77 FR 11798 (Rhode Island); 76 FR 27973
(Delaware); 77 FR 12770 (Nebraska); 77 FR 18052 (Colorado); 76 FR
16168 (Oklahoma); 77 FR 11914 (Vermont); 77 FR 11928 (Wisconsin); 76
FR 52604 (Kansas); 76 FR 64186 (Arkansas); 77 FR 11839 (Maryland);
76 FR 58570 (North Dakota); 77 FR 3966 (Illinois); 76 FR 76646
(South Dakota). EPA proposed limited approval and limited
disapproval of the Regional Haze SIPs of states covered by the Clean
Air Interstate Rule (CAIR), due to the remand of CAIR by the D.C.
Circuit. See, e.g. 77 FR 3691 (Jan. 25, 2012) (proposing limited
approval and limited disapproval of Virginia's Regional Haze SIP).
    \272\ See, e.g., 76 FR 34608 (California); 76 FR 42557
(Delaware); 76 FR 80754 (Kansas); 77 FR 19 (New Jersey); 77 FR 5191
(District of Columbia); 77 FR 14604 (Arkansas); 77 FR 17334
(Nevada); 77 FR 24845 (South Dakota); 77 FR 40150 (Nebraska); 77 FR
51915 (New York).
    \273\ Slip op. at 57.
---------------------------------------------------------------------------

    With respect to Arizona's Regional Haze SIP in particular, we note
that Arizona first made public its proposed 308 SIP during a comment
period beginning on October 28, 2010.\274\ At that time, EPA, the
National Park Service (NPS) (in consultation with the Fish and Wildlife
Service) and the U.S. Forest Service all submitted comments expressing
concern about the proposed SIP's compliance with the CAA, the RHR and
the BART Guidelines.\275\ Among other things, EPA noted that the SIP,
``does not provide a sufficient level of information and analysis to
support its conclusions.'' \276\ NPS provided extensive comments on the
proposed SIP, including detailed evaluations of ADEQ's BART analyses
for each of the three sources at issue in today's action.\277\ In each
instance, NPS concluded that ADEQ had not conducted a valid BART
analysis for NOX.\278\ The Forest Service concurred with the
initial comments provided by NPS on Arizona's BART exclusion process
and ``strongly disagree[d] with the adequacy of the Arizona reasonable
progress analysis.'' \279\ Therefore, ADEQ had the benefit not only of
the generally applicable requirements of the RHR, the

BART Guidelines and EPA Guidance, but also specific guidance from EPA
and the FLMs pointing out shortcomings in its Regional Haze SIP.
Following receipt of these comments, Arizona had the opportunity to
revise its SIP to address the deficiencies identified by the
commenters, but in most instances it chose not to do so.\280\
---------------------------------------------------------------------------

    \274\ Arizona Regional Haze SIP, Appendix E, Public Process.
Approximately 60 days prior to the public comment period, ADEQ sent
a draft of the SIP to the National Park Service and U.S. Forest
Service.
    \275\ Id.
    \276\ Id. Letter from Colleen McKaughan, EPA, to Eric Massey,
ADEQ (Dec. 2, 2010).
    \277\ Id. NPS Initial Comments Arizona Draft Section 308
Regional Haze SIP (Nov. 29, 2010); NPS General BART Comments on ADEQ
BART Analyses (Nov. 29, 2010); NPS Comments AEPCO--Apache Generating
Station BART Analysis and Determination (Nov. 29, 2010); NPS
Comments APS Cholla Generating Station BART Analysis and
Determination (Nov. 29, 2010); NPS Comments SRP's Coronado
Generating Station BART Analysis and Determination (Nov. 29, 2010);
NPS Comments on ADEQ BART Exemptions, (Dec. 1, 2010).
    \278\ Id.
    \279\ U.S. Forest Service Specific Comments: Arizona Regional
Haze SIP (Nov. 29, 2010).
    \280\ For example, in response to detailed comments from NPS
regarding the efficiency and cost of SCR, ADEQ stated that:
    ADEQ has determined that the cost computations presented by the
facilities in support of their BART applications are reasonable.
Many of the computations are based on vendor data and site-specific
conditions. The Department does not agree that the computations
over-estimate the costs of retrofit technologies and under-estimate
the associated emission decreases and visibility improvement.
---------------------------------------------------------------------------

    Finally, while we agree that, in the absence of an expired
statutory duty and a court-ordered deadline to issue a FIP, it would be
preferable for us to give Arizona additional time to revise its
Regional Haze SIP prior to promulgation of a FIP, we simply do not have
this option under these circumstances. As explained in our response to
the previous comment, we are obligated to issue a FIP to address any
gaps left by partial disapprovals of Arizona's Regional Haze SIP.
Nonetheless, we encourage ADEQ to submit a revised SIP to replace the
FIP and will work with ADEQ to develop such a revised plan to meet the
requirements of the CAA and the RHR.
    Comment: One commenter (Earthjustice) stated that the CAA's
Regional Haze program establishes a national regulatory floor and
requires states to develop RH SIPs at least as stringent as this floor
(citing 40 CFR 51.308). According to the commenter, ADEQ's SIP is
legally and technically inadequate because it does not require adequate
BART emission limits, does not achieve ``reasonable progress'' are
required by the RHR and would fail to achieve natural visibility goals
by 2064. The commenter believes that the Arizona RH SIP fails to
establish a program that is at least as stringent as the national floor
and that therefore EPA has a legal obligation to disapprove the SIP and
to issue a FIP in its place under CAA section 110(c)(1).\281\
---------------------------------------------------------------------------

    \281\ The commenter cited Alaska Dep`t of Envtl. Conservation v.
EPA, 540 U.S. 461, 470, 484 (2004); Mont. Sulphur & Chem. Co. v.
EPA, 666 F.3d 1174, 1181 (9th Cir. 2012) to support the contention
that Congress structured the CAA to provide expansive EPA oversight
to ensure SIPs comply with the CAA. The commenter cited 42 U.S.C.
7410(c), (k); EME Homer City Generation, L.P. v. EPA, No. 11-1302,
----F.3d----, 2012 WL 3570721, at *17 (DC Cir. Aug. 21, 2012) to
support the principle that EPA must issue a FIP when it determines
that a SIP does not comply with the CAA.
---------------------------------------------------------------------------

    Response: We agree that the CAA, the RHR and the BART Guidelines
set out specific requirements that Regional Haze SIPs must meet in
order to be approved by EPA. Our action today addresses these
requirements as they apply to ADEQ's BART determinations for Apache,
Cholla and Coronado, but does not address the requirements as they
apply to the remainder of Arizona's Regional Haze SIP (e.g., the
reasonable progress goals set by the state). EPA will propose action on
these aspects of the SIP shortly and take final action after receiving
comments. As explained in the preceding responses, because of our prior
finding of failure to submit, we are required to issue a FIP for any
portion of the SIP that we cannot approve. Thus, we are promulgating a
FIP for those aspects of ADEQ's BART determinations for Apache, Cholla
and Coronado that we are not approving at this time.

G. Other Comments

 1. Comment on Public Health and Ecosystem Impacts
    Comment: A number of commenters provided comments on the potential
health effects of our proposal. A number of other commenters stated
that the Regional Haze program's sole focus is the improvement of
visibility in Class I areas, and is not a health-based or emissions
reduction program. In relation to the Regional Haze program, any EPA
emphasis on health and emissions reduction is inappropriate. One
commenter (SRP) stated that EPA's assertion of health benefits is
unsubstantiated by the proposed rule. A few commenters noted that the
air quality in Arizona varies from city to city, and stated that EPA
should focus on the areas with the poorest air quality first, such as
Phoenix.
    In contrast, one commenter (Earthjustice) stated that the same
pollutants that reduce visibility also cause significant public health
impacts. The commenter noted that NOX is a precursor to
ground level ozone, which is associated with respiratory diseases,
asthma attacks and decreased lung function, and that NOX
reacts with other substances to form particulates that can cause and
worsen respiratory diseases, aggravate heart disease, and lead to
premature death. The commenter indicated that SO2 increases
asthma symptoms, leads to increased hospital visits, and can form
particulates that aggravate respiratory and heart diseases and cause
premature death, and that PM can penetrate deep into the lungs and
cause health problems such as aggravated asthma, chronic bronchitis,
and heart attacks. Based on a report prepared by the Clean Air Task
Force, the commenter asserted that Cholla, Coronado and Apache
collectively cause approximately 41 deaths, 63 heart attacks and 747
asthma attacks annually.\282\ Several other commenters provided similar
comments concerning health effects.
---------------------------------------------------------------------------

    \282\ The commenter cited Clean Air Task Force, Death and
Disease From Power Plants, http://www.catf.us/fossil/problems/power_plants/existing/map.php?state=Arizona.
---------------------------------------------------------------------------

    Response: We acknowledge the commenters' concerns regarding the
adverse health impacts of haze-causing emissions. We agree that the
same PM2.5 emissions that cause visibility impairment can
cause respiratory problems, decreased lung function, aggravated asthma,
bronchitis, and premature death. We also agree that the same
NOX emissions that cause visibility impairment also
contribute to the formation of ground-level ozone, which has been
linked with respiratory problems, aggravated asthma, and even permanent
lung damage. Finally, we also agree that SO2 emissions that
cause visibility impairment also contribute to increased asthma
symptoms, lead to increased hospital visits, and can form particulates
that aggravate respiratory and heart diseases and cause premature
death. Thus, to the extent that this FIP will lead to reductions in
these pollutants, there will be co-benefits for public health. However,
for purposes of this action, we are not authorized to consider these
benefits and we have not done so.
    In our NPRM, while discussing Executive Order 13045 (Protection of
Children from Environmental Health Risks and Safety Risks), we stated
that, to the extent the proposed rule will limit emissions of
NOX, SO2 and PM10, the rule will have
a beneficial effect on children's health by reducing air pollution. In
this action, while discussing Executive Order 13045 (Protection of
Children from Environmental Health Risks and Safety Risks), we conclude
that this action does not have a disproportionate effect on children,
but again note that to the extent this final action will limit
emissions of NOX, SO2 and PM10, the
rule will have a beneficial effect on children's health by reducing air
pollution that causes or exacerbates childhood asthma and other
respiratory issues. However, we do not believe it is necessary or
appropriate to quantify the extent of this beneficial effect because we
are not relying upon health effects in the promulgation of this rule.
    Comment: One commenter (Earthjustice) stated that the RHR rule

provides important environmental benefits to plants and animals, soil
health and entire ecosystems. The commenter noted that NOX
and SO2 are the primary causes of acid rain, which acidifies
lakes and streams, can damage certain types of trees and soils and
accelerates the decay of building materials and paints, including
irreplaceable buildings and statues that are part of our nation's
cultural heritage. The commenter added that nitrogen deposition, caused
by wet and dry deposition of nitrates derived from NOX
emissions, causes well-known adverse impacts on ecological systems. The
commenter also noted that NOX is a precursor to ozone, which
impacts plants and ecosystems by interfering with plants' ability to
produce food and increasing their susceptibility to disease and
insects, and also contributes to wildfires and bark beetle outbreaks in
the West by depressing plant water levels and growth.
    Response: We appreciate the commenter's concerns regarding the
negative ecosystem impacts of emissions from the units at issue. We
agree that both NOX and SO2 cause acid rain and
can have negative impacts on ecosystems, damaging plants, trees, and
other vegetation (including crop yields), which could have a negative
effect on species diversity in our ecosystems. However, for purposes of
this Regional Haze action, we are not authorized to consider these
ecosystem impacts. Therefore, while we note the potential for co-
benefits to ecosystem health resulting from our action today, we have
not taken these potential benefits into account in this action.
2. Comments on Economic Impacts
    Comment: Many commenters, including state officials, private
citizens and representatives of local governments, schools, and
business groups, expressed concern over potential economic effects
resulting from EPA's proposed BART determinations, asserting that EPA's
action would result in rate increases and possibly closures of one or
more power plants. Some commenters cautioned EPA that rate increases
would impact at-risk populations, such as seniors on fixed incomes. The
commenters emphasized that the three plants have a large financial
impact on the communities where they are located (i.e., they provide
jobs and tax revenue) and expressed their concern over the three
plants' economic viability if the plants are forced to install SCR to
reduce NOX emissions. Several representatives of local
school districts discussed the harm that large increases in electric
power rates would do to their programs in this time of declining state
support, and one representative of a local, nonprofit hospital
similarly voiced the difficulty his facility would have in absorbing
large rate increases. One commenter discussed the multiplier effect by
which loss of income from any job losses or the reduction in disposable
income due to increased power bills would ripple through the local
economies and affect local businesses and employment. A few commenters
discussed the impact on Arizona's water rates, and advised EPA to
consider how these rate increases would affect Arizona's economy. A few
commenters asserted that the proposed rule is intended to eliminate
coal as a cheap and reliable energy source.
    By contrast, one commenter (Earthjustice) stated that the RHR
provides substantial economic benefits, which far outweigh the costs of
pollution control technologies such as SCR. The commenter noted that
EPA has valued the RHR's health benefits at $8.4 to $9.8 billion
annually. The commenter further asserted that requiring power plants to
invest in pollution controls creates short-term construction jobs as
well as permanent operations and management positions. In addition, the
commenter indicated that the national parks and wilderness areas
protected by the RHR serve as engines for sustainable local capital,
with national park visitors contributing approximately $30 billion to
local economies and supporting 300,000 jobs nationwide. Regarding
Arizona specifically, the commenter stated that over 4.3 million people
visited the Grand Canyon in 2010, and this supported over 6,800 jobs
and resulted in over $428 million in visitor spending, while tourism at
Petrified Forest National Park, Saguaro National Park and Chiricahua
National Monument in 2010 supported over 1,100 jobs and resulted in
over $74 million in visitor spending. The commenter contended that
studies show that national park visitors highly value clean air,
readily perceive haze and are willing to cut short visits to national
parks based on their perception of air quality.\283\
---------------------------------------------------------------------------

    \283\ The commenter cited and submitted as Exhibit 11 Abt
Assocs. Inc., Out of Sight: The Science and Economics of Visibility
Impairment, at ES-7 (2000), available at http://www.abtassociates.com/reports/ES-clear.pdf.
---------------------------------------------------------------------------

    Response: As explained in our prior responses regarding economic
issues, the BART Guidelines permit consideration of economic impacts
only under ``unusual circumstances'' where a potential control option
is expected to have a ``severe impact on plant operations'' or ``result
in significant economic disruption or unemployment.'' None of the
commenters have provided any evidence that our action today would
result in the closure of any of the affected units. We discuss many of
the potential economic impacts raised as concerns here in the context
of our analysis of affordability of controls to AEPCO, above. Finally,
we acknowledge that today's action may have positive economic impacts,
as described by Earthjustice. However, we have not taken potential
economic benefits into account in our action.
3. Comments From Tribal Representatives and Members
    Comment: One commenter (Navajo Nation) stated that comments on our
proposed actions were provided pursuant to its government-to-government
relationship with EPA. The commenter stated that this EPA rulemaking
has adverse implications for a pending BART FIP for Navajo Generating
Station, which is on Navajo Nation land and burns Navajo coal. The
commenter also stated that this rule could impact BART decisions for
Four Corners Power Plant, and San Juan Generating Station.
    The commenter states that EPA has an obligation to consult with
Navajo Nation on a government-to-government basis for EPA actions and
decisions that may affect the Navajo Nation's interests, and reminds
EPA that it must defer to tribal government policy decisions, just as
it would a state, when promulgating a FIP on tribal lands.
    The commenter further states that EPA has failed to analyze the
cumulative effects of this rulemaking and the planned and proposed EPA
actions on Navajo Generating Station, Four Corners Power Plant, and San
Juan Generating Station, including both visibility improvement and
potential regional economic impacts. The commenter noted that the
fossil fuel economy is vitally important to the Four Corners region and
the Navajo Nation, with many jobs and coal royalties at stake from loss
of the area's coal fired power plants and their associated mines. The
commenter states that EPA must consider these impacts, as well as the
impacts of utility rate increases, in this BART decision for
NOX.
    The commenter observed that it is possible to go forward without
imposing a FIP in Arizona, as evidenced by the renewed consideration
being given to the New Mexico regional haze SIP under the current stay
on the proposed FIP for that state. The commenter stated

that the Navajo Nation, where two power plants that are undergoing EPA
BART determinations are located, shares the concerns of Arizona and New
Mexico regarding the economic impacts of requiring SCR. The commenter
noted that the BART decision is not based only on the most effective
control measures, but is to be based on an analysis of five factors
which include non-air quality impacts such as economic impacts.
    The commenter also asserted that real data should underpin EPA's
decisions, rather than modeling alone. The commenter also contended
that a public health baseline is needed in order to chart any public
health improvements that result from such emission controls.
    Response: EPA appreciates the comments provided by the Navajo
Nation on our proposed action pursuant to its government-to-government
relationship with EPA. As part of separate rulemakings, EPA has engaged
in consultation with Navajo Nation regarding the Four Corners Power
Plant \284\ and San Juan Generating Station. EPA is currently engaged
in active consultation with the Navajo Nation and other affected tribes
on the Navajo Generating Station.
---------------------------------------------------------------------------

    \284\ See document titled: ``Timeline of all tribal
consultations on BART.docx'' in the docket for this final
rulemaking.
---------------------------------------------------------------------------

    Today's rule approves Arizona's SIP (in part) and implements a FIP
(in part) for Apache Units 2 and 3; Cholla Units 2, 3 and 4; and
Coronado Units 1 and 2. This action has no retroactive effect on final
BART determinations for other facilities. We disagree that this action
has a nexus to the BART determination for Navajo Generating Station,
because BART analyses, whether performed by the states or EPA, are
conducted on a source-by-source basis, applying all five statutory
factors to a facility on an individual basis. While there are certain
commonalities among the sources mentioned by the commenter (e.g., all
are coal-fired power plants), there are also significant differences
that necessarily affect the case-by-case BART analysis. For example,
the unit size, unit age, boiler type, existing controls, type of coal
burned and proximity to Class I areas vary significantly among these
sources. All of these differences have a bearing on at least one of the
BART factors and thus on the ultimate BART determination. Given these
various distinguishing factors, we do not agree that this rule will
affect our BART determination for Navajo Generating Station.
    We also do not agree that we are required to consider the
cumulative effects of today's rulemaking together with rulemaking
actions on other BART determinations as part of our action today. As
noted above, under the CAA, the RHR and the BART Guidelines, BART
determinations are made on a source-by-basis, taking into account the
five statutory factors. The cumulative improvements from the various
SIPs, FIPs, and BART determinations are addressed in analyses under the
RHR requirements for Reasonable Progress, Long Term Strategies and
future updates to the SIP, which are separate from BART analyses. These
cumulative improvements will be influenced by changes in hundreds or
thousands of emission sources, so are more appropriately addressed
through use of a grid model, such as CAMx or CMAQ, rather than the
CALPUFF model recommended in the BART Guidelines, which is geared to a
far lower number of sources, and lacks the detailed chemistry of the
grid models.
    With regard to the economic concerns raised by the commenter, we
are required by the CAA and the federal regulations implementing the
CAA's BART provisions to evaluate (1) cost of compliance, (2) the
energy and non-air quality environmental impacts of compliance, (3) any
existing pollution control technology in use at the source, (4)
remaining useful life of source, and (5) degree of improvement in
visibility which may reasonably be anticipated to result from the use
of such technology. As explained in our prior responses regarding
economic issues, the BART Guidelines permit consideration of economic
impacts only under ``unusual circumstances'' where a potential control
option is expected to have a ``severe impact on plant operations'' or
``result in significant economic disruption or unemployment.'' None of
the commenters have provided any evidence that our action today would
result in the closure of any of the affected units or result in
significant economic disruption. We also note that none of the sources
affected by today's rulemaking currently purchase coal from a mine that
operates on the Navajo Nation.
    We take our duty to estimate the cost of controls very seriously,
and make every attempt to make a thoughtful and well informed
determination. However, we do not consider a potential increase in
electricity rates to be the most appropriate type of analysis for
considering the costs of compliance in a BART determination.
Projections of electricity rate impacts are inherently fraught with
uncertainty due to the numerous variables involved and the complexity
of the regulatory regime governing the power sector. Nevertheless, as
discussed elsewhere in this document, as part of our consideration of
the affordability of controls on AEPCO, a small entity, we have
analyzed the potential rate increases associated with our proposal for
Apache Units 2 and 3. Given the uncertainty inherent in such an
analysis, we have used conservative assumptions in an effort to guard
against understating the potential rate impacts.
    Regarding the comment that EPA should not rely on modeling alone,
it is extremely difficult in observational analyses to sufficiently
control for all factors, including emissions from other sources, to be
able to isolate the impacts of closure of a facility. A model such as
CALPUFF essentially holds constant a number of factors in order to
isolate the impacts of a single source. As discussed elsewhere in this
document, EPA affirms that the regulatory version of CALPUFF is the
correct model to use for these BART determinations.
    Assessing human exposure and quantifying health benefits are
outside the scope of the requirements of the Regional Haze Rule. EPA
sets National Ambient Air Quality Standards (NAAQS) to establish levels
of air quality that are protective of public health, including the
health of sensitive populations, for a number of pollutants including
particulate matter. These ``sensitive'' populations include asthmatics,
children, and the elderly. At this time the Navajo Nation is not
identified as out of attainment with any of the NAAQS. However, EPA
recognizes that there are significant concerns about risk and exposure
to air pollutants on the Navajo Nation and EPA will continue
discussions with the Navajo Nation and will involve other federal
agencies, as appropriate, to help address these concerns.
    Comment: Various other representatives and members of the Hopi and
Navajo Tribes provided oral testimony and/or submitted written comments
at one or more of the public hearings. Most tribal community members
supported the proposed FIP and stated their belief that it will improve
air quality and human health in Arizona. Several commenters recounted
their personal experiences with the deterioration of visibility in the
rural areas in which they live, declining water supplies due to water
use in mining operations, and illnesses that they believe are
attributable to air pollution from the power plants and mines in the
area (e.g., asthma and bronchitis). A number of commenters pointed out
that there are numerous old power plants in and around the Navajo

Nation, which they believe are causing air pollution that contributes
to haze and an increase in the incidence of lung and heart disease and
cancer in humans, as well as harming native plants and animals. Some of
these commenters advocated for a conversion to renewable energy
sources, which they believe will provide jobs, improve health, and
reduce emissions that contribute to climate change. One commenter
specifically suggested that EPA promote alternatives like natural gas
and algae ponds as a source of energy.
    One commenter indicated that reduced haze would improve tourism,
resulting in increased jobs and tax receipts. Another tribal commenter
stated that before acting, EPA should evaluate the impact on employment
and on the Hopi's revenue from coal if the FIP causes power plants to
close.
    One tribal commenter alleged that the National Academy of Sciences
did a study a number of years ago that concluded that some areas of the
country could be designated as ``national sacrifice areas'' that would
be used for national priorities, irrespective of resulting permanent
environmental damages. According to the commenter, many Indian
reservations are located in such areas, such as all of the Navajo and
Hopi reservations. The commenter asserted that the study concluded that
the well-being of the people in such areas can be forfeited so that the
rest of the country can enjoy cheap energy.
    Response: EPA acknowledges the comments. Neither Section 169A of
the CAA nor the BART Guidelines requires that BART analyses include or
quantify benefits to health or tourism or impact on employment. EPA
does not intend for this action to cause any power plants to close.
Although a quantitative analysis of the health and tourism benefits is
beyond the scope of what is required under BART EPA agrees with
commenters that emission reductions achieved to improve visibility will
also improve air quality. Improved air quality, in turn, affects public
health and may enhance tourism in the area. EPA notes that even if we
had quantified the benefits to health and tourism, such an analysis
would not likely have altered the outcome of our BART determination.
    Renewable energy technology is not a retrofit option for the
sources subject to BART and is therefore outside the scope of our BART
determination. As noted in the BART Guidelines, ``[w]e do not consider
BART as a requirement to redesign the source when considering available
control alternatives. For example, where the source subject to BART is
a coal-fired electric generator, we do not require the BART analysis to
consider building a natural gas-fired electric turbine although the
turbine may be inherently less polluting on a per unit basis.'' \285\
Therefore, we did not consider such alternatives as part of our BART
analyses. Nonetheless, we acknowledge that many kinds of renewable
energy do not produce haze-causing pollutants, and transitioning to
those sources of energy could lead to visibility improvements.
---------------------------------------------------------------------------

    \285\ BART Guidelines, 40 CFR Part 51, Appendix Y, section
IV.D.1.
---------------------------------------------------------------------------

    The CAA applies equally to all parts of the United States. In
making a determination in this case, we have applied the applicable
provisions of the CAA and the RHR. We have also considered other
applicable requirements, including Executive Order 12898,\286\ which
establishes federal executive policy on environmental justice. This
Executive Order directs federal agencies, to the greatest extent
practicable and permitted by law, to make environmental justice part of
their mission by identifying and addressing, as appropriate,
disproportionately high and adverse human health or environmental
effects of their programs, policies, and activities on minority
populations and low-income populations in the United States.
---------------------------------------------------------------------------

    \286\ 59 FR 7629, February 16, 1994.
---------------------------------------------------------------------------

    EPA has determined that our final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it increases the
level of environmental protection for all affected populations without
having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population. This rule requires emissions reductions of NOx from
three facilities in Arizona. The partial approval of the SIP approves
state law as meeting Federal requirements.
    Comment: One commenter suggested that EPA investigate the
technology of cooling steam exhaust through a magnetic refrigerator to
remove NO2 as a liquid, since it would condense at the
relatively high temperature of 294 K or 70 degrees F (boiling point).
    Response: The BART Guidelines provide that:

    Technologies which have not yet been applied to (or permitted
for) full scale operations need not be considered as available; we
do not expect the source owner to purchase or construct a process or
control device that has not already been demonstrated in
practice.\287\
---------------------------------------------------------------------------

    \287\ BART Guidelines, 40 CFR Part 51, Appendix Y, section
IV.D.1.

---------------------------------------------------------------------------
The Guidelines further provide that:

    In order to provide certainty in the process, all technologies
should be considered if available before the close of the State's
public comment period. You need not consider technologies that
become available after this date.

The commenter has not provided evidence that this technology has been
demonstrated in practice or that it was available before the close of
the State's public comment period. Therefore, we have not considered it
as a potential control option. An additional consideration is that
typically 90 percent of the NOX from combustion is emitted
in the form of NO, rather than NO2. Since the boiling point
of NO is 121 K or -242 degrees F, much lower than for NO2,
and the stack exit temperature is the range of 300-400 K or 120-280
degrees F, a large degree of cooling would be necessary to condense the
NO, and so the energy costs could be substantial.
4. Requests for Extension of Comment Period and Additional Hearings
    Comment: A number of commenters remarked on EPA's timeline for
soliciting public comments, and stated that they believe that the time
allowed was insufficient. One commenter requested more public hearings,
and another commenter requested a 90-day extension of the deadline for
comments (starting from July 18, 2012), so that the public has ample
time to review, analyze, comment, and react to the rule and in
particular EPA's Technical Support Document. The commenter added that
an extension would allow the ADEQ the opportunity to further
collaborate with EPA in revising the state's SIP submittal (for the
purpose of nullifying the proposed FIP), and thereby adhering to the
intent of the CAA.
    Response: As explained above, our proposed rule, which was signed
on July 2, 2012 and published in the Federal Register on July 20,
2012,\288\ provided for a public hearing in Phoenix, Arizona, on July
31, 2012, and a public comment deadline of August 31, 2012. In response
to requests from various parties for a longer comment period and
additional hearings, we extended the public comment period to a total
of sixty days from publication in the Federal Register.\289\ We also
scheduled two more public hearings in

Southern Arizona (Benson) and in Northern Arizona (Holbrook) on August
14 and 15, 2012, respectively.
---------------------------------------------------------------------------

    \288\ 77 FR 42834.
    \289\ See 77 FR 45326 (July 31, 2012).
---------------------------------------------------------------------------

    Comment: One comment letter signed by 728 residents, business
owners, citizens and other interested parties urged EPA to extend the
comment period on our proposal and provide additional hearings near the
Cholla Power Plant.
    Response: As noted the preceding response, we extended the comment
period on our propose rule and we held additional public hearings,
including one in Holbrook, Arizona, near the Cholla Power Plant.

V. Summary of Final Action

    EPA is taking final action to approve in part and disapprove in
part a portion of Arizona's SIP for Regional Haze and to promulgate a
FIP for the disapproved elements of the SIP. This final action
addresses only the State's BART determinations for the specified units
at the three power plants. We will propose action on the remainder of
Arizona's Regional Haze SIP in a separate notice. EPA takes very
seriously a decision to disapprove portions of a state plan. In this
instance, we find that the State's NOX BART determinations
for the coal-fired units are not consistent with the requirements of
the Act and the RHR. In addition, the SIP lacks the necessary
compliance deadlines and requirements for equipment maintenance and
operation, including monitoring, recordkeeping and reporting
requirements for all pollutants at all of the BART units. As a result,
we find that this final disapproval is the only path that is consistent
with the Act at this time.
    EPA estimates this action will improve visibility at 18 Class I
areas by reducing NOX emissions from three power plants by
about 22,700 tons per year. The total costs associated with these
reductions, according to the supplemental cost analysis we performed
based on cost estimates provided by the facility owners, are summarized
in Table 18.

                                                     Table 18--Summary of Supplemental Cost Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Annualized                          Total
                                                                       Capital cost   capital cost ($/  Annual O&M ($/  annualized cost       Cost-
                                                                           ($)              yr)              yr)             ($/yr)       effectiveness
--------------------------------------------------------------------------------------------------------------------------------------------------------
Apache Unit 2......................................................      $82,481,439       $7,785,664       $1,760,600       $9,546,264           $3,450
Apache Unit 3......................................................       82,481,439        7,785,664        1,760,600        9,546,264            2,973
Cholla Unit 2......................................................       87,713,386        8,279,523        1,626,683        9,906,206            2,979
Cholla Unit 3......................................................       83,461,195        7,878,146        1,570,766        9,448,912            2,838
Cholla Unit 4......................................................      119,083,832       11,240,671        2,350,182       13,590,853            3,083
Coronado Unit 1....................................................       80,633,219        7,611,205        4,492,736       12,103,941            2,135
Coronado Unit 2....................................................        2,500,000          235,982  ...............          235,982            1,900
--------------------------------------------------------------------------------------------------------------------------------------------------------

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This action finalizes approval of a source-specific portion of the
Arizona SIP and a Regional Haze FIP for units at three facilities in
Arizona. This action is not a rule of general applicability, and not a
``significant regulatory action'' under the terms of Executive Order
12866 (58 FR 51735, October 4, 1993). This type of action is exempt
from review under Executive Order (EO) 12866 (58 FR 51735, October 4,
1993) and is therefore not subject to review under Executive Order
13563 (76 FR 3821, January 21, 2011).

 B. Paperwork Reduction Act