\16\ We are finalizing our proposed approval of the State's PM
BART determinations. We did not receive any adverse comments that
were sufficient to convince us that reexamination of the State's
control costs was warranted.
---------------------------------------------------------------------------

    EPA notes that, in considering the visibility improvements
reflected in our revised modeling, EPA interprets the BART Guidelines
to require consideration of the visibility improvement from BART
applied to the entire BART-eligible source. The BART Guidelines explain
that, ``[i]f the emissions from the list of emissions units at a
stationary source exceed a potential to emit of 250 tons per year for
any visibility-impairing pollutant, then that collection of emissions
units is a BART-eligible source.'' In other words, the BART-eligible
source (the list of BART emissions units at a source) is the collection
of units for which one must make a BART determination. The BART
Guidelines state ``you must conduct a visibility improvement
determination for the source(s) as part of the BART determination.''
This requires consideration of the visibility improvement from BART
applied to the BART-eligible source as a whole.
    We note, however, that while our regulations require states and EPA
to assess visibility improvement on a source-wide basis, they provide
flexibility to also consider unit-specific visibility improvement in
order to more fully inform the reasonableness of a BART determination,
but that does not replace the consideration of visibility benefit from
the source (facility) as a whole. In making the BART determinations in
this final action we have considered visibility improvements at the
source, and then also at the units that comprise the source.
    As explained in more detail later in this decision, we received
during the comment period significant input on expected costs
associated with different control technologies. We discuss in the
section above and in our response to comments, the changes we made in
response to comments received on costs of different control
technologies. As discussed above and in our response to comments, we
have revised our modeling analysis in light of the input we received
during the public comment period. This additional information and
analysis result in different costs and visibility benefits, two of the
five BART factors. In some cases this leads us to finalize our
proposal, and in other cases to reach a different conclusion.
    This decision, which addresses multiple facilities in a state where
numerous Class 1 areas are impacted to a greater or lesser degree,
illustrates clearly the case-by-case nature of the BART determination
process. The interplay among the five factors, and in particular the
cost and visibility factors, is highly significant and determinative of
the outcome. In considering this information, as we have noted in prior
decisions, our first assessment is whether the state's determination is
reasonable in light of the facts and consistent with the requirements
of the Clean Air Act and implementing regulations. If we determine that
it is, even if we might have reached a different outcome if it were our
decision to make in the first instance, we will approve the SIP.
    Below is a more specific discussion of our determinations in the
final decision. As stated above more detailed information on our
determinations can be found in the response to comments sections of
this rulemaking.

A. Laramie River

    The State's regional haze SIP determined that NOX BART
for Laramie River Units 1, 2, and 3 is new LNB/SOFA. We proposed to
disapprove the State's determination because the State neglected to
reasonably assess the costs of compliance and visibility improvement in
accordance with the BART Guidelines. 78 FR 34766. After revising the
State's costs and modeling and re-evaluating the statutory factors, we
proposed to determine that NOX BART is LNB/SOFA + SCR, with
an emissions limit of 0.07 lb/MMBtu for each unit. We sought comment
generally on the BART factors and our control determinations and
indicated that we could revise our control determinations depending on
any new information that we received.
    As the result of the comments received on our proposal, we have
further revised our calculation of the costs of compliance and
visibility modeling. We have considered any comments on the other BART
factors but we have not changed our assessment of the other BART
factors. The revised visibility modeling for the most impacted Class I
area (Badlands) is presented in the following table.

                             Table 18--Visibility Modeling for Laramie River Station
----------------------------------------------------------------------------------------------------------------
       Laramie River Station                LNB/SOFA           LNB/SOFA + SNCR             LNB/SOFA + SCR
----------------------------------------------------------------------------------------------------------------
Unit 1.............................  0.18 deciviews.......  0.28 deciviews.......  0.57 deciviews
Unit 2.............................  0.18 deciviews.......  0.27 deciviews.......  0.53 deciviews
Unit 3.............................  0.18 deciviews.......  0.27 deciviews.......  0.52 deciviews
                                    ----------------------------------------------------------------------------
    Total *........................  0.54 deciviews.......  0.82 deciviews.......  1.62 deciviews
----------------------------------------------------------------------------------------------------------------
* The total visibility improvement was estimated as the sum of the visibility improvement from each unit.

    We also considered the visibility improvement at other impacted
Class I areas (Wind Cave, Rawah, and Rocky Mountain), which range from
0.25 to 0.47 deciviews, 0.26 to 0.43 deciviews, and 0.23 to 0.44
deciviews, for Units 1, 2, and 3, respectively. Further details
regarding our revised visibility modeling and cost estimates were
provided in section III.A.
    After re-evaluating the BART factors, we continue to find that LNB/
SOFA + SCR is reasonable as BART and are therefore finalizing our
proposal. The visibility improvement associated with LNB/SOFA + SCR at
the most impacted Class I area is significant on both a source-wide
(1.62 deciviews) and unit-specific (0.52-0.57 deciviews) basis. The
significant visibility improvement at three other impacted Class I
areas also supports the selection of this option. Finally, we believe
that the incremental visibility improvement at the most impacted Class
I area of SCR over SNCR (nearly double in all cases) warrants the
selection of the most stringent control.
    In regards to the costs of compliance, we found that the revised
average and incremental cost-effectiveness of LNB/SOFA + SCR is in line
with what we have found to be acceptable in our other FIPs. The average
cost-effectiveness per unit ranges from $4,375 to $4,461/ton, while the
incremental cost-effectiveness ranges from $5,449 to $5,871/ton. We
believe that these costs are reasonable, especially in light of the
significant visibility improvement associated with LNB/SOFA + SCR. As a
result, we are finalizing our proposed disapproval of the State's
NOX BART determination for Laramie River Station and
finalizing our proposed FIP that includes a NOX BART
determination of LNB/SOFA + SCR,

with an emission limit of 0.07 lb/ MMBtu (30-day rolling average).

B. Jim Bridger

    The State's regional haze SIP determined that NOX BART
for Jim Bridger Units 1-4 is new LNBs with SOFA. The State also
determined that SCR should be installed at each unit as part of the
State's long-term strategy to achieve reasonable progress at several
Class I areas, and set compliance dates of December 31, 2022, December
31, 2021, December 31, 2015, and December 31, 2016 for Units 1-4,
respectively.
    In our proposal, we indicated that the State had neglected to
reasonably assess the costs of compliance and visibility improvement
for Jim Bridger in accordance with the BART Guidelines. We nonetheless
proposed to approve the State's BART and reasonable progress
determinations for Units 3 and 4 because the compliance deadlines to
install SCR on these units were sufficient to meet the requirements of
BART. We are now finalizing our proposed action for Units 3 and 4.
    We also proposed to approve the State's BART and reasonable
progress determinations for Units 1 and 2, but on a different basis.
There, we indicated that given the number of SCR retrofits PacifiCorp
had to perform in Wyoming and in other states, it might not be
affordable for PacifiCorp to install two additional SCRs on Jim Bridger
Units 1 and 2 within the five-year BART compliance period. We requested
additional information from commenters regarding whether the
affordability provisions of the BART Guidelines should be applied to
Units 1 and 2. In the alternative, we proposed to find that
NOX BART for Units 1 and 2 was an emission limit of 0.07 lb/
MMBtu (30-day rolling average) based on the installation of LNB/SOFA +
SCR with a compliance deadline of five years. Under this scenario, we
acknowledged that the cost-effectiveness of LNB/SOFA + SCR at Units 1
and 2 was within the range of what EPA and the State itself had found
reasonable in other BART determinations. We also considered the
significant visibility improvement demonstrated by the State's modeling
to warrant LNB/SOFA + SCR as BART. Finally, we sought comment generally
on the BART factors and our control determinations and indicated that
we could revise our control determinations depending on any new
information that we received.
    In response to our proposal, we received both supportive and
adverse comments regarding whether the affordability provisions of the
BART Guidelines should apply to Units 1 and 2. As explained in more
detail in our responses to these comments, we agree that PacifiCorp did
not make a sufficient showing that it could not afford to install LNB/
SOFA + SCR on Units 1 and 2 within the five-year compliance period.
Nevertheless, we also received new information regarding the costs of
compliance and visibility benefits associated with Jim Bridger and have
revised our cost estimates and visibility modeling for all four units
accordingly. We have considered any comments on the other BART factors
but we have not changed our assessment of the other BART factors.
    The revised visibility modeling for the most impacted Class I area
(Bridger) is presented in the following table (with straight font
representing modeled results using an ammonia background based on a
monitored monthly varying concentration, italicized font representing
modeled results using IWAQM default 0.5 ppb background ammonia).\17\
---------------------------------------------------------------------------

    \17\ Air Quality Modeling Protocol: Wyoming Regional Haze
Federal Implementation Plan, U.S. EPA, January, 2014.

                                  Table 19--Visibility Modeling for Jim Bridger
----------------------------------------------------------------------------------------------------------------
           Jim Bridger                  LNB/SOFA         LNB/SOFA + SNCR               LNB/SOFA + SCR
----------------------------------------------------------------------------------------------------------------
Unit 1..........................  0.17/0.23 deciviews  0.20/0.27 deciviews  0.27/0.37 deciviews
Unit 2..........................  0.16/0.21 deciviews  0.19/0.25 deciviews  0.27/0.36 deciviews
Unit 3..........................  0.14/0.19 deciviews  0.17/0.23 deciviews  0.26/0.35 deciviews
Unit 4..........................  0.25/0.23 deciviews  0.30/0.28 deciviews  0.45/0.42 deciviews
                                 -------------------------------------------------------------------------------
    Total *.....................  0.72/0.86 deciviews  0.86/1.03 deciviews  1.25/1.5 deciviews
----------------------------------------------------------------------------------------------------------------
* The total visibility improvement was estimated as the sum of the visibility improvement from each unit.

    We also considered the visibility improvements at other impacted
Class I areas (Bridger, Fitzpatrick, Rawah, Rocky Mountain, Grand
Teton, Teton, Washakie, and Yellowstone), which range from 0.26 to 0.91
deciviews, 0.26 to 0.89 deciviews, 0.24 to 0.87 deciviews, and 0.27 to
1.0 deciviews, for Units 1-4, respectively. Further details regarding
our revised visibility modeling and cost estimates are provided in
section III.A.
    After re-evaluating the BART factors, we are approving the State's
determination that LNB/SOFA is NOX BART for Units 1-4. The
visibility improvement associated with LNB/SOFA + SCR at the most
impacted Class I area is significant on a source-wide basis (1.25 to
1.5 deciviews). The fact that Jim Bridger Station affects a number of
other Class I areas, which also would see appreciable visibility
improvement with the installation of LNB/SOFA + SCR, also weighs in
favor of selecting this option as BART. The unit-specific benefits for
Units 1 and 2 are somewhat more modest (0.27-0.37 deciviews), however,
especially considering the low incremental improvement over SNCR (0.07-
0.11 deciviews). The incremental visibility improvement of SNCR over
LNB/SOFA is even smaller (0.03-0.04 deciviews).
    In regards to the costs of compliance, we found that the revised
average cost-effectiveness of LNB/SOFA + SCR is in line with what we
have found to be acceptable in our other FIPs. The average cost-
effectiveness is $4,088 and $4,461/ton at Units 1 and 2, respectively.
The incremental cost-effectiveness, on the other hand, is on the high
end of what we have found to be reasonable in our other FIPs. The
incremental cost-effectiveness is $7,477 and $8,986/ ton at Units 1 and
2, respectively.
    Ultimately however, while we believe that these costs and
visibility improvements could potentially justify LNB/SOFA + SCR as
BART, because this is a close call and because the State has chosen to
require SCR as a reasonable progress control, we believe deference to
the State is appropriate in this instance. We are therefore finalizing

our approval of the State's determination to require SCR at Jim Bridger
Units 1-4, with an emission limit of 0.07 lb/MMBtu (30-day rolling
average), as part of its long-term strategy. We are also finalizing our
approval of the compliance dates of December 31, 2022, December 31,
2021, December 31, 2015, and December 31, 2016 for Units 1- 4
respectively.

C. Dave Johnston Units 3 and 4

    The State's regional haze SIP determined that NOX BART
for Dave Johnston Units 3 and 4 is LNB/OFA. We proposed to disapprove
the State's determination because the State neglected to reasonably
assess the costs of compliance and visibility improvement in accordance
with the BART Guidelines. 78 FR 34778. After revising the State's costs
and modeling and re-evaluating the statutory factors, we proposed to
determine that NOX BART for Unit 3 is LNB/SOFA + SCR, with
an emission limit of 0.07 lb/ MMBtu (30-day rolling average). We
proposed that NOX BART for Unit 4 is LNB/SOFA + SNCR, with
an emission limit of 0.12 lb/ MMBtu. We sought comment generally on the
BART factors and our control determinations and indicated that we could
revise our control determinations depending on any new information that
we received.
    As the result of the comments received on our proposal, we have
further revised our calculation of the costs of compliance and
visibility modeling. We have considered any comments on the other BART
factors but we have not changed our assessment of the other BART
factors. The revised visibility modeling for the most impacted Class I
area (Wind Cave) is presented in the following table.

                           Table 20--Visibility Modeling for Dave Johnston (BART Units)
----------------------------------------------------------------------------------------------------------------
           Dave Johnston                    LNB/OFA             LNB/OFA + SNCR             LNB/OFA + SCR
----------------------------------------------------------------------------------------------------------------
Unit 3.............................  0.33 deciviews.......  0.39 deciviews.......  0.51 deciviews
Unit 4.............................  0.41 deciviews.......  0.46 deciviews.......  0.57 deciviews
                                    ----------------------------------------------------------------------------
    Total *........................  0.74 deciviews.......  0.85 deciviews.......  1.08 deciviews
----------------------------------------------------------------------------------------------------------------
* The total visibility improvement was estimated as the sum of the visibility improvement from each unit.

    We also considered the visibility improvement at other impacted
Class I areas (Badlands, Mt Zirkel, Rawah, and Rocky Mountain), which
range from 0.20 to 0.47 deciviews and 0.24 to 0.55 deciviews, for Units
3 and 4, respectively. Further details regarding our revised visibility
modeling and cost estimates were provided in section III.A.
    After re-evaluating the BART factors, we no longer believe that
LNB/OFA + SNCR is NOX BART for Dave Johnston Unit 4. As we
explained in the proposal, the incremental cost-effectiveness of LNB/
OFA + SCR was and continues to be excessive ($13,312), so we have
eliminated this control option. While the revised average and
incremental costs of LNB/OFA + SNCR continue to be reasonable, the
incremental visibility improvement of SNCR over LNB/OFA is now only
0.05 deciviews. In light of this new visibility information, we believe
that the State's determination that LNB/OFA is NOX BART for
Unit 4 was reasonable and are approving it accordingly.
    In regards to Dave Johnston Unit 3, we continue to believe that
LNB/OFA + SCR is NOX BART. The visibility improvement
associated with LNB/SOFA + SCR at the most impacted Class I area is
significant (0.51 deciviews). The visibility improvement at several
other impacted Class I areas also supports the selection of this
option. Finally, we do not believe that the incremental visibility
improvement at the most impacted Class I area of SCR over SNCR (0.12
deciviews) is sufficiently insignificant to warrant the elimination of
the most stringent control in this instance.
    In regards to the costs of compliance, we found that the revised
average and incremental cost-effectiveness of LNB/SOFA + SCR is in line
with what we have found to be acceptable in our other FIPs. The average
cost-effectiveness is $2,635/ton, while the incremental cost-
effectiveness is $7,583/ton. We believe that these costs are
reasonable, especially in light of the significant visibility
improvement associated with LNB/SOFA + SCR.
    In response to other comments we received, we also considered an
alternative BART analysis for Unit 3 based on PacifiCorp's commitment
to retire Unit 3 by 2027 in lieu of installing SCR. Using a 9-year
remaining useful life as the amortization period for Unit 3, the
incremental cost-effectiveness of LNB/OFA + SCR becomes excessive
($11,781). Furthermore, the incremental visibility improvement at the
most impacted Class I area from use of LNB/OFA to use of LNB/OFA+ SNCR
is only 0.06 deciviews. Thus, taking all five factors into account,
including the remaining useful life of nine years, we conclude that the
NOX BART would be LNB/OFA in this scenario.
    To provide flexibility, we are finalizing both scenarios in a FIP
for Dave Johnston Unit 3. Under the first scenario, we are finalizing a
NOX BART determination of LNB/OFA + SCR, with an emission
limit of 0.07 lbs/ MMBtu (30-day rolling average). Under the
alternative scenario, based on a commitment to retire Unit 3 by 2027,
we are finalizing a NOX BART determination of LNB/OFA, with
an emission limit of 0.28 lbs/ MMBtu (30-day rolling average).

D. Naughton

    The State's regional haze SIP determined that NOX BART
is new LNB/OFA for Naughton Units 1 and 2 and LNB/OFA + SCR for
Naughton Unit 3. We proposed to approve the State's determination for
Unit 3, but proposed to disapprove the State's determination for Units
1 and 2 because the State neglected to reasonably assess the costs of
compliance and visibility improvement in accordance with the BART
Guidelines. 78 FR 34748. After revising the State's costs and modeling
and re-evaluating the statutory factors, we proposed to determine that
NOX BART for Units 1 and 2 is LNB/SOFA + SCR, with an
emissions limit of 0.07 lb/MMBtu for each unit. We sought comment
generally on the BART factors and our control determinations and
indicated that we could revise our control determinations depending on
any new information that we received.
    As the result of the comments received on our proposal, we have
further revised our calculation of the costs of compliance and
visibility modeling. We have considered any comments on the other BART
factors but we have not changed our assessment of the other BART
factors. The revised visibility modeling for the most impacted Class I
area (Bridger) is presented in the following table (with straight font
representing modeled

results using an ammonia background based on a monitored monthly
varying concentration, italicized font representing modeled results
using IWAQM default 0.5 ppb background ammonia).

                                   Table 21--Visibility Modeling for Naughton
----------------------------------------------------------------------------------------------------------------
               Naughton                        LNB/OFA               LNB/OFA + SNCR           LNB/OFA + SCR
----------------------------------------------------------------------------------------------------------------
Unit 1...............................  0.22/0.26 deciviews....  0.26/0.30 deciviews....  0.33/0.39 deciviews.
Unit 2...............................  0.28/0.32 deciviews....  0.34/0.38 deciviews....  0.42/0.46 deciviews.
Unit 3...............................  0.05/0.07 deciviews....  0.20/0.29 deciviews....  0.49/0.60 deciviews.
                                      --------------------------------------------------------------------------
    Total *..........................  0.55/0.65 deciviews....  0.80/0.97 deciviews....  1.24/1.45 deciviews
----------------------------------------------------------------------------------------------------------------
* The total visibility improvement was estimated as the sum of the visibility improvement from each unit.

    We also considered the visibility improvement at other impacted
Class I areas (Fitzpatrick, North Absaroka, Washakie, Teton, Grand
Teton, and Yellowstone), which range from 0.10 to 0.30 deciviews, 0.08
to 0.42 deciviews, and 0.13 to 0.49 deciviews, for Units 1, 2, and 3,
respectively. Further details regarding our revised visibility modeling
and cost estimates were provided in section III.A.
    After re-evaluating the BART factors, we no longer believe that
LNB/OFA + SCR is NOX BART for Naughton Units 1 and 2. The
visibility improvement associated with LNB/SOFA + SCR at the most
impacted Class I area remains significant on a source-wide basis (1.24-
1.45 deciviews) but more modest on a unit-specific basis (0.33-0.46
deciviews). The visibility improvement at six other impacted Class I
areas continues to support the selection of this option as well. In
regards to the costs of compliance, however, we found that while the
revised average cost-effectiveness values for LNB/OFA + SCR were
acceptable, the revised incremental cost-effectiveness values were
beyond the upper end of the range (higher even than Jim Bridger) of
what we have found to be acceptable in our other FIPs. For Units 1 and
2, respectively, the average cost-effectiveness per unit is $3,109 and
$2,566/ ton, while the incremental cost-effectiveness is $10,384 and
$8,440/ ton. Consequently, we believe that it was not unreasonable for
the State to reject LNB/OFA + SCR as BART. Furthermore, we cannot say
the State acted unreasonably in rejecting LNB/OFA + SNCR at Units 1 and
2 because the incremental visibility improvement of SNCR over LNB/OFA,
while possibly appreciable, is very low at just 0.10 deciviews across
both units. Therefore, based on our analysis we believe that the
State's determination that LNB/OFA is NOX BART for Units 1
and 2, with an emission limit of 0.28 lbs/ MMBtu, was ultimately
reasonable and are approving it accordingly.

E. Wyodak

    The State's regional haze SIP determined that NOX BART
for Wyodak Unit 1 is new LNBs with OFA. We proposed to disapprove the
State's determination because the State neglected to reasonably assess
the costs of compliance and visibility improvement in accordance with
the BART Guidelines. 78 FR 34784-34785. As a result, we also proposed a
FIP for NOX BART. After considering the BART factors, we
noted that the cost-effectiveness and visibility improvement of the
most stringent control option, LNB/OFA + SCR, were within the range of
values that EPA had found reasonable in other FIPs. However, we
proposed not to require LNB/OFA + SCR as NOX BART for Wyodak
Unit 1. Instead, we proposed to require LNB/OFA + SNCR based on the
reasoning that the cumulative visibility improvement of SCR across all
Class I areas was low when compared to the cumulative visibility
improvement associated with SCR at Dave Johnston Unit 3, Laramie River
Units 1-3, and Naughton Units 1 and 2. We sought comment generally on
the BART factors and our control determinations and indicated that we
could revise our control determinations depending on any new
information that we received. Based on our discussion of LNB/OFA + SCR
at Wyodak, that control option was among those that we invited comment
on.
    In response to our proposal for Wyodak, we received comments that
cumulative visibility improvement should not be used as a basis to
reject a control option that has already been deemed reasonable based
on visibility improvement at the most impacted Class I area. The
commenters pointed out that such an approach would have the illogical
effect of allowing an added benefit (visibility improvement at multiple
Class I areas) to weigh in favor of less stringent controls. We agree
with this criticism and want to make clear today that where a control
is warranted as BART based on the costs of controls and visibility
benefits at the most impacted area alone, cumulative visibility
benefits can only strengthen the case for that control, not suggest
that it is unwarranted. Similarly, where a control might not be
warranted as BART based on the improvement at a single Class I area,
significant cumulative benefits are an additional consideration that
could warrant that the control be selected as BART.
    In addition, we have further revised our calculation of the costs
of compliance and visibility modeling for Wyodak Unit 1. We have not
changed our assessment of the other BART factors. The revised
visibility modeling for the most impacted Class I area (Wind Cave) is
presented in the following table.

                                    Table 22--Visibility Modeling for Wyodak
----------------------------------------------------------------------------------------------------------------
               Wyodak                       LNB/SOFA           LNB/SOFA + SNCR             LNB/SOFA + SCR
----------------------------------------------------------------------------------------------------------------
Unit 1.............................  0.21 deciviews.......  0.32 deciviews.......  0.61 deciviews.
----------------------------------------------------------------------------------------------------------------

    We also considered the visibility improvement at a second impacted
Class I area (Badlands), which is a maximum of 0.38 deciviews for LNB/
SOFA + SCR. Further details regarding our revised visibility modeling
and cost estimates were provided in the previous section.

    After re-evaluating the BART factors and dismissing our earlier
rationale for rejecting an otherwise reasonable control, we find that
LNB/SOFA + SCR is reasonable as BART. As the BART-eligible source in
this case is a single unit, the source-wide and unit-specific
visibility improvements associated with the various control options are
the same. The visibility improvement associated with LNB/SOFA + SCR at
the most impacted Class I area (0.61 deciviews) is significant. There
is also a more modest visibility improvement (0.38 deciviews) at a
second impacted Class I area that supports the selection of this
option. Finally, we believe that the incremental visibility improvement
at the most impacted Class I area of SCR over SNCR (nearly double)
warrants the selection of the most stringent control.
    In regards to the costs of compliance, we found that the revised
average and incremental cost-effectiveness of LNB/SOFA + SCR is in line
with what we have found to be acceptable in our other FIPs. The average
cost-effectiveness is $4,036/ton, while the incremental cost-
effectiveness of SCR over SNCR is $6,223/ton. We believe that these
costs are reasonable, especially in light of the significant visibility
improvement associated with LNB/SOFA + SCR at Wind Cave. As a result,
we are finalizing our proposed disapproval of the State's
NOX BART determination for Wyodak Unit 1. Additionally,
after carefully considering adverse comments, we have decided not to
finalize our proposed NOX determination of LNB/SOFA + SNCR,
but rather are finalizing a NOX BART determination of LNB/
SOFA + SCR, with an emission limit of 0.07 lb/ MMBtu (30-day rolling
average).

F. Dave Johnston Units 1 and 2 (Reasonable Progress)

    We proposed to disapprove the State's determination to not impose
LNB/OFA as reasonable progress controls for NOX at Dave
Johnston Units 1 and 2. Based on our original cost estimates and
visibility modeling, we also proposed to require PacifiCorp Dave
Johnston Units 1 and 2 to meet a FIP emission limit of 0.22 lb/MMBtu
(30-day rolling average) (assuming the installation of LNB/OFA). Based
on our revised cost estimates and visibility modeling that we developed
in response to comments, however, we no longer conclude that reasonable
progress controls are warranted this planning period. While we continue
to disagree with the State's reasoning for not imposing controls (as
detailed in our response to comments), we are not prepared to say the
State's ultimate decision was unreasonable. In evaluating the four
reasonable progress factors and the visibility improvement associated
with potential controls, we found that the average and incremental
cost-effectiveness of LNB/OFA ($990/ton and $1,221/ton, respectively),
while reasonable if viewed in isolation, was not necessarily justified
this planning period in light of the relatively modest visibility
improvement predicted by the revised modeling (0.11 deciviews--0.12
deciviews at the most impacted Class I area). As a result, we are
approving the State's reasonable progress determination of no new
controls for Dave Johnston Units 1 and 2, but we expect the State to
revisit the issue during the next planning period.

V. Issues Raised by Commenters and EPA's Responses

A. Legal Issues

1. EPA Authority and State Discretion
    Comment: Multiple commenters stated that CAA Section 169A and the
Regional Haze Rule (RHR) give the states the lead in developing their
regional haze SIPs. Some commenters went further in stating that
Wyoming is given almost complete discretion in creating its regional
haze SIP. These commenters argued that, because Wyoming is given such
discretion, EPA lacks the statutory authority to disapprove the State's
regional haze SIP. Specifically, some commenters pointed to the
flexibility the State is granted in developing its BART determinations
and other RHR requirements. The commenters stated that the CAA
anticipates that EPA will create guidance and that the states, using
their discretion, will use this guidance to develop regional haze SIPs.
The State of Wyoming and other parties argued that each factor in the
five-factor analysis used to make its BART determinations was
appropriately weighed based on the State's own discretion. The
commenters therefore argue that EPA has no basis on which to disapprove
the five-factor analysis and that EPA does not have authority to reject
a state's BART determination solely because EPA would have conducted
the analysis in a different way or reached a different conclusion. The
commenters went on to say that the State, after considering all
statutory factors, made BART determinations for all subject-to-BART
sources in a manner consistent with 40 CFR Part 51 Appendix Y, the
established CAA requirements, and the interests of the State of
Wyoming.
    Numerous commenters went on to say that the U.S. Court of Appeals
for the D.C. Circuit has affirmed that EPA's role in determining BART
is limited and that a state's role is paramount. The court found that
the CAA ``calls for states to play the lead role in designing and
implementing regional haze programs.'' Am. Corn Growers Ass'n v. EPA,
291 F.3d 1, 2 (D.C. Cir. 2002). The commenters stated that the court
also reversed a portion of EPA's original RHR because it found that
EPA's method of analyzing visibility improvements distorted the
statutory BART factors and was ``inconsistent with the Act's provisions
giving the states broad authority over BART determinations.'' Id., see
also Utility Air Regulatory Group v. EPA, 471 F.3d 1333, 1336 (D.C.
Cir. 2006) (The second step in a BART determination ``requires states
to determine the particular technology that an individual source
`subject to BART' must install.'').
    The commenters asserted that states have the primary responsibility
for preventing air pollution under the CAA. CAA section 101(a)(3), 42
U.S.C. 7401(a)(3). Pursuant to this principle, states, not EPA, have
always had primary control over decisions to impose specific emission
limits (and therefore specific pollution control technologies) for
individual facilities. By congressional design, EPA ``is relegated . .
. to a secondary role in the process of determining and enforcing the
specific, source-by-source emission limitations which are necessary [to
meet] national standards.'' Train v. NRDC, 421 U.S. 60, 79 (1975). This
basic division of responsibilities between EPA and the states remained
unchanged when Congress amended the Act in 1977 and again in 1990. See
Virginia v. EPA, 108 F.3d 1397, 1408-09 (D.C. Cir. 1997).
    Response: Congress crafted the CAA to provide for states to take
the lead in developing SIPs, but balanced that decision by requiring
EPA to review the SIPs to determine whether they meet the requirements
of the CAA. EPA's review of SIPs is not limited to a ministerial type
of automatic approval of a state's decisions. See North Dakota v. EPA,
730 F.3d 750, 760-61 (8th Cir. 2013) (``Although the CAA grants states
the primary role of determining the appropriate pollution controls
within their borders, EPA is left with more than the ministerial task
of routinely approving SIP submissions.'') (hereinafter ``North
Dakota''). EPA must consider not only whether the State considered the
appropriate factors, but whether the State acted reasonably in doing
so. In undertaking such a review, EPA does not ``usurp'' the State's
authority, but ensures that such authority is reasonably exercised. EPA
has the authority to issue a FIP either

when EPA has made a finding that the state has failed to timely submit
a SIP or when EPA has found a SIP deficient. Here, EPA has authority on
both grounds, and we have approved as much of the Wyoming regional haze
SIP as possible, while promulgating a FIP only to fill the remaining
gaps. Our action today is consistent with the statute.
    Our action does not contradict the Supreme Court's decision in
Train. States have significant responsibilities in the implementation
of the CAA and meeting the requirements of the RHR. We recognize that
states have the primary responsibility of drafting a SIP to address the
requirements of the CAA's visibility program. We also recognize that we
have the responsibility of ensuring that SIPs, including regional haze
SIPs, conform to CAA requirements. We cannot approve a regional haze
SIP that fails to address BART with a reasoned consideration of the
statutory and regulatory requirements of the CAA and the RHR. See
Oklahoma v. EPA, 723 F.3d 1201, 1207 (10th Cir. 2013) (``We agree with
the EPA that the statute provides the agency with the power to review
Oklahoma's BART determination for these four units.'') (hereinafter
``Oklahoma'').
    Contrary to the commenters' assertions, we recognize the State's
primary responsibility in drafting a SIP. In fact, we have approved
many of the State's determinations, including the entirety of Wyoming's
Section 309 BART alternative for SO2 emissions. We are
disapproving the State's NOX BART determinations, as the CAA
requires, because the State neglected to properly consider the costs of
compliance and the visibility benefits associated with several of the
available control options.
    We also disagree that our proposal is inconsistent with the
American Corn Growers and Utility Air Regulatory Group decisions. These
cases dealt with EPA's authority to issue broad regulations that
prescribed how states must conduct their BART determinations. They did
not address EPA's authority to review regional haze SIPs for compliance
with the mandates of the CAA or EPA's now finalized implementing
regulations. The Tenth Circuit, in concluding that EPA had authority to
disapprove a BART determination that did not follow the BART
Guidelines, stated that the American Corn Growers opinion ``does not
alter this conclusion.'' Oklahoma v. EPA, 723 F.3d 1201, 1208 (10th
Cir. 2013).
    Because the CAA sets certain mandatory statutory deadlines and
provides for citizen suits when the Administrator fails to perform a
mandatory duty, we are required by the terms of a consent decree to
ensure that Wyoming's CAA requirements for regional haze are finalized
by January 10, 2014. Because we have found that the State's regional
haze SIP did not satisfy CAA and RHR requirements in full and because
we have previously found that Wyoming failed to timely submit its
regional haze SIP, we have not only the authority, but a statutory duty
to promulgate a FIP that meets those requirements. We have reviewed
this decision in light of other decisions made by us, as well as
decisions made in other states SIPs. Our action today in large part
approves the regional haze SIP submitted by Wyoming. Our disapproval of
Wyoming's NOX BART and reasonable progress determinations
and imposition of a FIP is not intended to encroach on State authority.
Rather, our action today is required by the CAA to ensure that the
State has a complete plan in place to address the CAA's visibility
requirements.
    Comment: The fact that Congress gave states primacy in making BART
determinations is noteworthy and related to the fact that the regional
haze program is focused on an aesthetic benefit, not a public health
standard. Under other sections of the CAA, primarily those dealing with
health-based standards, Congress directed EPA to establish standards
that do not take costs into consideration. States then develop plans to
meet those health-based standards. Under the New Source Performance
Standards program (section 111 of the CAA) and National Emission
Standards for Hazardous Air Pollutants program (section 112), EPA
routinely establishes specific emission limits for large industrial
sources. The regional haze program, which deals with an aesthetic
standard, was clearly laid out by Congress to be different in its
approach, to avoid establishing emission limits, to give states
authority to decide appropriate controls, and allow states to weigh the
costs against the benefits.
    Response: We do not agree with this commenter's characterization of
the regional haze program or the CAA's visibility requirements. While
it is true that the goal of CAA sections 169A and 169B is to improve
visibility in national parks and wilderness areas rather than to
prevent adverse human health effects, Congress structured the program
so that states' decisions had to be made in the form of SIPs, which EPA
has the authority to review for compliance with all CAA requirements.
Furthermore, Congress did not create an approach that would allow
states to avoid establishing emission limits. On the contrary, Congress
specifically directed EPA's regulations to require states to devise
``emission limits . . . necessary to make reasonable progress,'' CAA
section 169A(b)(2), including the requirement to establish BART, which
the RHR defines as ``an emission limitation.'' 40 CFR 51.301.
    Comment: EPA's actions leave nothing under the CAA's framework by
which Wyoming could make an approvable BART determination. EPA has
overreached and exceeded its statutory authority by proposing a FIP
that replaces Wyoming's considered judgment with EPA's priorities and
policy choices.
    Response: We disagree with this comment. EPA is not substituting
its judgment for that of the State of Wyoming or issuing a FIP merely
to advance priorities and policy choices. Rather, we have determined
that Wyoming did not properly follow the BART Guidelines or the CCM in
conducting its BART analyses and, therefore, did not correctly consider
the costs of compliance or the visibility benefits associated with
available control technologies as the CAA requires. Consequently, we
are finalizing a FIP in today's action to remedy the gaps left by these
inadequacies. We note, however, that the CAA's framework provides
Wyoming with the opportunity to submit a SIP revision at any time that
could replace all or a portion of EPA's FIP, and we encourage Wyoming
to do so.
    Comment: EPA clearly gave the states more discretion through
rulemaking when it split the universe of BART sources impacted by the
BART Guidelines into power plants greater than 750 megawatts (MW) and
all others. States were merely encouraged to follow the BART Guidelines
for the smaller BART sources. EPA says in the preamble ``that states
should view the guidelines as helpful guidance for these other
categories.'' In saying this, EPA is affording even more discretion to
the states in making BART determinations for the smaller BART sources.
EPA has proposed disapproval of Wyoming's BART determination and
proposed a FIP for one of these smaller sources, the Wyodak Unit 1 335
MW power plant. The State believes that the EPA is again overreaching
in its action by proposing a FIP for Wyodak Unit 1, where Wyoming was
not even required to follow the BART Guidelines in arriving at its BART
determination.
    Response: We agree that the BART Guidelines are only mandatory for

``fossil-fuel fired power plants having a total generating capacity
greater than 750 megawatts.'' 40 CFR 51.308(e)(1)(ii)(B). However, the
fact that a state may deviate from the procedures in the BART
Guidelines when selecting BART for smaller EGUs does not mean that a
state has unfettered discretion to act unreasonably or inconsistently
with the CAA or the RHR. Ultimately, a state must still adopt the
``best available retrofit technology,'' CAA section 169A(b)(2)B); 40
CFR 51.308(e)(1)(ii)(A), while reasonably considering the five
statutory factors.
    The RHR further defines BART to mean ``an emission limitation based
on the degree of reduction achievable through the application of the
best system of continuous emission reduction for each pollutant which
is emitted by an existing stationary facility.'' 40 CFR 51.301
(emphasis added). We do not interpret this requirement to allow a state
to dismiss the best system of continuous emission reduction under the
mantle of unlimited state discretion. As we discuss elsewhere in this
document, Wyoming erroneously evaluated costs and visibility benefits
when analyzing the various control options available for Wyodak, and
thereby did not reasonably consider the statutory factors and select
the best system of control.
    Comment: EPA's RHR gave states the flexibility to choose
alternatives to the BART process, such as participation in a trading
program. EPA spells out in the preamble that this ``substantial
flexibility'' provides the ``states the ability to choose the least
costly and least burdensome alternative.'' EPA and 28 states on the
east coast took advantage of this flexibility when it declared that the
cap and trade program for ozone nonattainment would, for the most part,
satisfy the requirements of BART. The important point here is that EPA
wanted and pushed for flexible, cost-savings approaches to address
regional haze. EPA is still pushing for approval of the Cross States
Air Pollution Rule (CSAPR) as a solution to regional haze problems on
the east coast.
    There appears to be a consistency issue within the EPA over the
application of flexibility. Wyoming does not think EPA meant for an
approach to promote costs savings and less burdensome solutions to be
restricted to one area of the country or certain types of solutions.
However, EPA's proposal to partially disapprove Wyoming's regional haze
SIP and impose more costly and burdensome FIP requirements for seven
BART units in the State of Wyoming appear to be inconsistent with EPA's
purported ``substantial flexibility.'' EPA's failure to recognize
Wyoming's discretion in these areas is arbitrary and capricious.
    Response: Wyoming had the opportunity to submit better-than-BART
alternatives in lieu of source-specific NOX BART
determinations. Wyoming did not do so. Because Wyoming did not take
advantage of the flexibility afforded by better-than-BART alternatives,
we must review Wyoming's BART determinations for compliance with the
applicable requirements of the CAA, RHR, and BART Guidelines. Our
proposal clearly laid out the bases for our proposed disapproval of the
State's NOX BART determinations, and we have relied on the
standards contained in our regulations and the authority that Congress
granted us to review and determine whether Wyoming's regional haze SIP
complied with the minimum statutory and regulatory requirements. To the
extent a cost analysis relies on values that are inaccurate, a state
has not considered cost in a reasoned or reasonable fashion. To the
extent a state has considered visibility improvement from potential
emissions controls in a way that substantially understates the
improvement or does so in a way that is not consistent with the CAA,
the state has not considered visibility improvement in a reasoned or
reasonable fashion. In these circumstances--as discussed in more detail
in the proposed notice and this final notice--EPA is required to
disapprove the relevant aspects of the SIP. In determining SIP
adequacy, we must exercise our judgment and expertise regarding complex
technical issues, and it is entirely appropriate that we do so. Courts
have recognized this necessity and deferred to our exercise of
discretion when reviewing SIPs. See, e.g., Connecticut Fund for the
Env't., Inc. v. EPA, 696 F.2d 169 (2nd Cir. 1982); Michigan Dep't. of
Envtl. Quality v. Browner, 230 F.3d 181 (6th Cir. 2000); Mont. Sulphur
& Chem. Co. v. EPA, 2012 U.S. App. LEXIS 1056 (9th Cir. Jan. 19, 2012).
    Comment: One commenter asserted that the U.S. Court of Appeals for
the D.C. Circuit's decision to vacate CSAPR is relevant to the Wyoming
FIP. EME Homer City Generation, L.P. v. EPA., 696 F.3d 7 (D.C. Cir.
2012), cert. granted 570 U.S. (June 24, 2013) (No. 12-1182) (CSPAR
Decision), and stated that EPA's proposed Wyoming FIP exceeds EPA's
statutory authority. The commenter also states that in vacating CSAPR,
the D.C. Circuit held that EPA's ``FIP-first'' approach exceeds EPA's
authority because EPA issued a FIP at the same time it determined the
emission reduction parameters that the states were supposed to
implement. The commenter stated that EPA's theory was that EPA can
define the end goals and simultaneously issue federal plans to
implement them, upending that process and placing the Federal
Government firmly in the driver's seat at both steps.
    Other commenters stated that the D.C. Circuit's rejection of the
CSAPR rule is irrelevant to EPA's regional haze rulemaking for Wyoming.
They asserted that the regional haze program differs from the CAA's
good-neighbor provision in fundamental ways that make the court's
rejection of CSAPR irrelevant to EPA's action on Wyoming's regional
haze plan. The commenters stated that the CAA's visibility provisions
establish a technology-based standard for eligible major sources,
including PacifiCorp's coal-fired power plants in Wyoming. See 42
U.S.C. 7491(b)(2)(A). To help achieve ``reasonable progress'' toward
the national visibility goal, eligible sources must install BART for
haze-causing pollutants. Id. BART is defined as: ``an emission
limitation based on the degree of reduction achievable through the
application of the best system of continuous emission reduction for
each pollutant which is emitted by an existing stationary facility.''
40 CFR 51.301. The emission limitation must be established on a case-
by-case basis, taking into consideration the technology available, the
costs of compliance, the energy and non-air quality environmental
impacts of compliance, any pollution control equipment in use or in
existence 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. Unlike the D.C.
Circuit's interpretation of the good-neighbor provision, the BART
definition establishes a floor for emissions reductions, but no
ceiling. States must ensure that eligible sources install the best
pollution control devices.
    These commenters also argued that when a SIP fails to establish a
program that meets CAA requirements, then EPA has an obligation to
promulgate a FIP. Here, they argued, EPA carried out its statutory duty
in proposing a partial FIP for Wyoming. EPA's role is not mere
``rubber-stamping'' of poor SIPs. EPA ``has a duty to evaluate the
adequacy of the existing SIP as a whole when approving SIP revisions.''
Ass'n of Irritated Residents v. EPA, 632 F.3d 584, 591 (9th Cir. 2011).
A FIP ``fill[s] all or a portion of a gap or otherwise correct[s] all
or a portion of an inadequacy in a State implementation plan.'' 42
U.S.C.

7602(y) (emphasis added). In proposing to reject many of Wyoming's
inadequate BART determinations, and proposing a partial FIP, EPA is
merely acting to fulfill its own regulatory obligations under the Act.
    Response: With respect to the comment that we lacked authority to
promulgate a FIP due to the D.C. Circuit's decision in EME Homer City,
we disagree. In EME Homer City, the D.C. Circuit vacated 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 CSAPR exceeded EPA's authority under section 110
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 EPA had quantified their obligations for emissions
reductions.
    In the regional haze context, 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 (64 FR 35714). 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. (70 FR
39104). The revised RHR and the BART Guidelines were upheld by the D.C.
Circuit in Utility Air Regulatory Group v. EPA, 471 F.3d 1333 (D.C.
Cir. 2006).\18\ 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.\19\ 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.\20\
---------------------------------------------------------------------------

    \18\ 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 Wyoming's BART determinations at issue
here.
    \19\ 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.
    \20\ 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 (74 FR 2392),
triggering a FIP clock under CAA section 110(c). By this time, states
already had more than three years since issuance of the final BART
Guidelines 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 and approved, in
part or in whole, the vast majority of these SIPs.21 22 This
stands in contrast to the situation in EME Homer City, 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.''
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).
---------------------------------------------------------------------------

    \21\ 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).
    \22\ 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).
---------------------------------------------------------------------------

    One commenter also pointed to the D.C. Circuit's general statements
concerning state and federal roles under the CAA and argues that EPA
has exceeded its statutorily mandated role in proposing to disapprove
portions of Wyoming'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 is inconsistent with those principles. In this action, we
are fulfilling our statutory duty to review Wyoming'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
Wyoming'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 proposed notices and elsewhere in
this document, we have concluded that five of Wyoming's BART
determinations \23\ and four elements of the regional haze SIP \24\ did
not comply with the requirements of the CAA and the RHR. Based on these
findings, we are required to disapprove these portions of Wyoming's
regional haze SIP. As discussed in detail in several below responses,
the CAA provides EPA with the authority to review and reject an
inadequate regional haze SIP. Oklahoma v. EPA, 723 F.3d 1201, 1207
(10th Cir. 2013).
---------------------------------------------------------------------------

    \23\ As presented elsewhere in this final notice and in the
docket, the five NOX BART determinations we are
disapproving are for the following: PacifiCorp Dave Johnston Unit 3,
PacifiCorp Wyodak Unit 1, and Basin Electric Laramie River Units 1,
2, and 3.
    \24\ As presented elsewhere in this final notice and in the
docket, the four elements of the State SIP we are disapproving
include: (1) Wyoming's RPGs; (2) The State's monitoring,
recordkeeping, and reporting requirements in Chapter 6.4 of the SIP;
(3) portions of the State's long term strategy (LTS) that rely on or
reflect other aspects of the regional haze SIP that we are
disapproving; and (4) the provisions necessary to meet the
requirements for the coordination of the review of the reasonably
attributable visibility impairment (RAVI) and the regional haze LTS.
---------------------------------------------------------------------------

    Comment: One commenter stated that the limits on EPA's authority to
reject a SIP were affirmed by the Fifth Circuit in Texas v. EPA, 690
F.3d 670 (5th Cir. 2012), vacating EPA's rejection of a Texas SIP
revision implementing its minor new source review program (i.e., the
Texas Flexible Permit Program). In the Texas decision, the court
reaffirmed the principle that if a SIP or SIP revision meets the
statutory criteria of the CAA, then EPA must approve it. The Wyoming
regional haze SIP meets the statutory criteria of the CAA. Therefore,
EPA's disapproval of the Wyoming regional haze SIP exceeds EPA's
statutory authority.
    Response: In Texas, the Fifth Circuit found that EPA had failed to
tie its disapproval to any specific requirement in the CAA or EPA's
implementing regulations.\25\ In this action, our disapproval is based
explicitly and squarely on the SIP's failure to comply with the CAA
section 169A(b)(2)(A), as implemented through the RHR and the

BART Guidelines. Just because a court found EPA's disapproval invalid
in one case does not mean that finding applies in all cases. This
situation involves a very different program under the CAA and a very
different state submittal and review. The Texas case does not involve
BART or the CAA's regional haze provisions at all. Rather, it involved
EPA's disapproval of SIP revisions involving Texas's minor new source
review program. There are a limited number of specific requirements in
EPA rules for minor source review programs. In contrast, regional haze
SIPs and BART determinations are subject to the detailed requirements
set forth in CAA section 169A, the RHR, and the BART Guidelines.
---------------------------------------------------------------------------

    \25\ 690 F.3d at 679, 682, 686.
---------------------------------------------------------------------------

    Comment: One commenter stated that the CSAPR decision criticized
the CSAPR's FIP-first approach because it forces states to ``take a
stab in the dark'' on their compliance obligations only to be judged
later whether they hit the mark. As the D.C. Circuit explained in the
CSAPR decision, a ``SIP logically cannot be deemed to lack a required
submission or deemed to be deficient for failure to meet . . . [an]
obligation before EPA quantifies the . . . obligation.'' EME Homer City
Generation, L.P. v. EPA., 696 F.3d 7, 49 (D.C. Cir. 2012), cert.
granted 570 U.S. (June 24, 2013) (No. 12-1182) (hereinafter ``CSPAR
Decision'').
    Other commenters reject this assertion, explaining that Wyoming was
not forced to take a ``stab in the dark'' in developing its regional
haze SIP. In EME Homer City, the D.C. Circuit accepted the state
petitioners' argument that they had no obligation to submit SIPs until
after EPA defined each state`s contribution to interstate pollution and
the necessary emissions reductions to address that contribution. EME
Homer City, 2012 WL 3570721, at *18 (``[L]ogically, a SIP cannot be
deemed to lack a required submission . . . until after EPA has defined
the State`s good neighbor obligation.''; ``There is no way for an
upwind State to know its obligation . . . until EPA defines it.'').
    Response: We do not agree that Wyoming was forced to take a ``stab
in the dark'' in developing its regional haze SIP. The regional haze
program and the interstate transport obligations under the CAA are
quite different. The states' regional haze obligations have been
clearly defined. EPA issued BART Guidelines establishing detailed
parameters for state BART determinations in 2005. Commenter's charge
that EPA may never issue a FIP in such circumstances is incorrect. We
explain in detail above how the CAA's visibility provisions and EPA's
implementing regulations differ from the good-neighbor provision at
issue in EME Homer City. Wyoming was well aware of these requirements
as it developed its regional haze SIP, through EPA comment letters and
meetings between EPA and the State. Finally, unlike the petitioners in
EME Homer City, none of the commenters here dispute that Wyoming's
regional haze SIP and BART determinations were ``required
submission[s].''
    Comment: One commenter stated that the CSAPR decision also made
clear that any FIP issued by EPA must be related to the ``end goal of
the statute.'' The D.C. Circuit stated in the CSAPR decision: ``[T]he
end goal of the statute is attainment in the downwind state. EPA's
authority to force reductions on upwind states ends at the point where
the affected downwind State achieves attainment.'' CSAPR Decision at p.
25.
    The ``end goal'' of the regional haze statutory requirements is to
gradually achieve ``natural visibility'' conditions by the year 2064
under an emission reduction approach known as reasonable progress as
determined by the states. EPA's rush in the proposed Wyoming FIP to
front-load as many emission reductions as possible in the first five
years of this decades-long program is a clear indication that EPA has
lost sight of the ``end goal'' of the regional haze program. Likewise,
EPA's failure to account for, and properly address, other causes of
visibility impairment in its FIP, such as natural causes (forest
fires), out of state sources, oil and gas sources, etc., demonstrates
that EPA has lost focus on the ``end goal'' of the regional haze
program. EPA's proposed Wyoming FIP violates this ``end goal''
principle espoused by the CSAPR decision.
    Response: EPA is required to evaluate BART factors included in
state SIPs (e.g., ultimately rejecting methodological flaws and data
flaws in estimating costs of compliance and visibility, as we have done
in this final action), where the flaws in the analysis prevented the
State of Wyoming from conducting meaningful consideration of the BART
factors, as required by the BART Guidelines, and moored to the CAA's
BART and SIP provisions. North Dakota v. EPA, 730 F.3d 750, 761 (8th
Cir. 2013).
    Furthermore, we do not agree that one provision of the CAA should
be read and applied in isolation. The commenter's position would ignore
the rest of the CAA's statutory requirements and violate the
``fundamental canon of statutory construction that the words of a
statute must be read in their context and with a view to their place in
the overall statutory scheme.'' A court must therefore interpret the
statute ``as a symmetrical and coherent regulatory scheme,'' and ``fit,
if possible, all parts into an harmonious whole.'' FDA v. Brown &
Williamson Tobacco Corp., 529 U.S. 120, 133 (2000) (quoting Davis v.
Michigan Depart of Treasury, 489 U.S. 803, 809 (1989); Gustafson v.
Alloyd Co., 513 U.S. 561, 569 (1995); and FTC v. Mandel Brothers, Inc.,
359 U.S. 385, 389 (1959)). The commenter's claim that one provision in
the CAA overrides all other statutory provisions is unfounded and not
supported by the CAA. In particular, the statutory requirements for
BART are separate and distinct from the statutory requirements for
reasonable progress.
    Moreover, as explained elsewhere in this document, EPA's action
fully accounts for other causes of visibility impairment. With respect
to wildfires, we explain in detail elsewhere in this document the role
that fires play in determining natural background conditions. With
respect to oil and gas sources, we are approving the State's
determination to not impose controls on this source category during
this planning period, in part because the State already applies minor
source BACT to many of them through the State's SIP-approved minor NSR
program, and in part because controls on these sources are not so cost-
effective that we are prepared to say the State was unreasonable. With
respect to accounting for out-of-state sources, we cited sources
outside the Western Regional Air Partnership (WRAP) domain as one
factor that made it reasonable for our RPGs to fall short of the
uniform rate of progress (URP) and unreasonable to achieve the URP.
Finally, we note that we are approving some of Wyoming's BART
determinations and all of Wyoming's reasonable progress determinations.
Additionally, BART is required in the first planning period, which ends
in 2018, and is required to be installed as expeditiously as
practicable, but in no event later than five years after the effective
date of this final notice. In light of the fact that many of Wyoming's
Class I areas are not even expected to meet the URP this planning
period, the notion that EPA has required ``front-loading'' of controls
is utterly without merit.
    Comment: Some commenters stated that the CSAPR decision considered,
and then rejected, a ``reasonableness'' standard put forth by EPA as
the only limit on its authority to impose emission reductions under the
CSAPR. CSAPR Decision at p. 37, ftnt. 23. EPA likewise purports to
impose a

reasonableness standard as adequate justification for rejecting the
Wyoming regional haze SIP and imposing a FIP. The CSAPR decision makes
clear that such a reasonableness standard, not included in the CAA
itself, does not have a place in justifying EPA's actions in issuing a
FIP. For this added reason, the CSAPR decision makes clear the FIP
exceeds EPA's statutory authority.
    Response: EPA disagrees with this comment. First, the commenters
misunderstand the cited footnote in the CSAPR decision. In the D.C.
Circuit's view, EPA ignored statutory limits on its authority and
instead claimed that reasonableness was the only bound on EPA's
authority. Here, EPA makes no such claim. EPA, of course, has the
authority and the duty to review Wyoming's SIP for compliance with the
CAA and the RHR.
    In reviewing the Wyoming regional haze SIP, EPA has determined that
a ``reasonableness'' standard is in fact harmonious with the CAA and
the RHR, and the courts have agreed. Oklahoma v. EPA, 723 F.3d 1201,
1207 (10th Cir. 2013) (``The EPA therefore had a reasonable basis for
rejecting the 2008 Cost Estimates [that were based on the overnight
costing method] as not complying with the guidelines.''); see also
North Dakota v. EPA, 730 F.3d 750, 761 (8th Cir. 2013) (explaining EPA
is not required to ``approve a BART determination that is based upon an
analysis that is neither reasoned nor moored to the CAA's
provisions'').
    The CAA requires states to submit SIPs that contain such measures
as may be necessary to make reasonable progress toward achieving
natural visibility conditions, including BART. The CAA accordingly
requires the states to submit a regional haze SIP that includes BART as
one necessary measure for achieving natural visibility conditions. See
Alaska Dep't of Envtl. Conservation v. EPA, 540 U.S. 461, 500 (2004)
(in a related context, holding that EPA validly issued stop work orders
because the state's BACT determination ``simply did not qualify as
reasonable in light of the statutory guides.'' (emphasis added))
(hereinafter ``ADEC''). Thus we are not establishing a new
reasonableness standard, as the commenter asserts.
    Comment: In the CSPAR decision, the D.C. Circuit found it
``inconceivable'' that Congress would bury in the CAA ``an open-ended
authorization for EPA to effectively force every power plant in the
upwind States to install every emissions control technology EPA deems
`cost effective'.'' CSAPR Decision at p. 40. In so finding, the court
refused to transform a ``narrow'' provision into a ``broad and
unusual'' authority that would overtake other core provisions of the
Act.'' Id. Similarly, it is inconceivable in the regional haze context
that Congress would bury an open-ended authorization allowing EPA to
ignore its own BART Guidelines, overrun carefully crafted state
regional haze SIPs and BART determinations, and require the
installation of expensive emission controls which result in minimal
regional haze improvements. This principle espoused in the CSAPR
decision is particularly applicable in the regional haze context where,
just like in the CSAPR, EPA's BART determinations in the Wyoming FIP
are ``not a clear numerical target--far from it--until EPA defines the
target.'' CSAPR Decision at p. 48. And in spite of EPA initially
helping to define ``the target'' by issuing its BART Guidelines (which
EPA subsequently ignored), EPA did not begin to redefine the target
until it began to issue various determinations around the country in
reaction to various state regional haze SIPs. Even then, EPA's
``target'' is not clear and certainly is impossible to determine, on a
state or source-by-source basis, until EPA sets the target in a state-
specific FIP.
    Like the upwind states in the CSAPR decision, it was ``impossible''
for Wyoming to determine its regional haze obligation ``until EPA
defined it.'' Id. This process effectively allows EPA to impose any
standard it wants with little ability for the states (or sources) to
achieve the redefined target through a state-led process because of the
tight deadlines imposed by EPA as a result of negotiated consent decree
deadlines.
    Response: We do not agree that we have ignored the CAA and BART
Guidelines. As explained in our proposed notice and elsewhere in this
document, our decisions are firmly grounded on the CAA provisions and
BART Guidelines, and Wyoming was well aware of these requirements as it
developed its SIP. In addition, the comparison of BART determinations
and the CSAPR decision is not appropriate. In contrast to CSPAR, the
CAA and RHR do not set specific numerical targets for BART
determinations. Instead, they require states to reasonably consider the
five statutory factors, which, as we have detailed in our proposal and
in our response to comments, Wyoming did not do. Furthermore, EPA
provided extensive comments to the State on the proposed regional haze
SIP and met with the State on numerous occasions, so the State was
aware of EPA's concerns regarding approvability before the SIP was
submitted to EPA. As explained below in greater detail, the Consent
Decree that covers this action has not hindered Wyoming's ability to
develop and submit an approvable SIP. Wyoming can submit new SIP
revisions, and request that EPA review and approve them, to replace the
FIP elements at any time.
    To the extent that the comment argues that the RHR itself is
invalid for similar reasons to those for which the D.C. Circuit vacated
CSAPR, the time to make those arguments has passed.
    Finally, in establishing the BART requirements, Congress was
addressing a category of large sources that pre-dated the modern NSR
affected sources, which were determined to significantly contribute to
regional haze and set an expectation that included consideration of
cost, feasibility, and effect on regional haze (as well as the other
five factors) for those sources, many of which did not have modern
pollution controls because of their age and because they hadn't been
addressed through ozone SIPs the way so many eastern sources had. This
is one of the reasons why the western regional haze SIPs are seeing
emission controls.
    Comment: One of the commenters stated that one of the key
conclusions of the CSAPR decision was that EPA exceeded the scope of
its authority by requiring emission reductions beyond the statutory or
regulatory requirements. In the CSAPR decision, the court looked at the
fact that once EPA had determined that an upwind emission source
contributed ``significantly'' to nonattainment or maintenance of the
standard in a downwind state; it was ``in'' for purposes of requiring
emission reductions. The emission reduction requirements were then
based on cost-effectiveness thresholds that were applied uniformly
throughout the CSAPR region. In other words, all emissions that could
be reduced, for example, for a cost between $1 and $500 per ton were
effectively required. The court held that this approach resulted in a
situation where some sources had to bear a disproportionate amount of
costs, based on their relative contribution to the nonattainment or
maintenance problem.
    Similarly in the regional haze context, EPA established an ``in or
out'' criteria of a 0.5 deciview impact. Sources with modeling results
that suggested the impact was greater than 0.5 were ``in'' and required
further analysis. If, under EPA's FIP approach, the facilities could
cost-effectively (as determined by EPA, not the states) control
emissions, they were required to do so. Oftentimes, EPA has required
the controls notwithstanding the negligible contribution the emission
reductions

will have towards meeting the requirement of the RHR. EPA's conclusions
requiring individual sources to reduce emissions under its subjective
cost-effectiveness criteria have no relationship to visibility impacts
or improvements, and EPA failing to conduct that modeling, but
supporting a determination of reasonableness of controls ``based on the
high cost effectiveness at each of the units.'' 77 FR at 33034, 33038
and 33055.
    EPA's conclusions regarding emission reductions that are based on
the cost-effectiveness of controls without an appropriate linkage to
visibility improvement and meeting the goals and objectives of the RHR
exceed EPA's statutory authority as suggested by the CSAPR decision.
    Response: We agree with some of this comment and disagree with
other portions. As an initial matter, as we explained in our proposed
notice, we note that:

    Wyoming used a contribution threshold of 0.5 deciviews for
determining which sources are subject-to-BART. By using a
contribution threshold of 0.5 deciviews, Wyoming exempted seven of
the fourteen BART-eligible sources in the State from further review
under the BART requirements. Based on the modeling results, the
State determined that P4 Production, FMC Granger, and OCI Wyoming
had an impact of .07 deciview, 0.39 deciview, and 0.07 deciview,
respectively, at Bridger Wilderness. Black Hills Neil Simpson 1,
Sinclair Casper Refinery, and Sinclair--Sinclair Refinery have an
impact of 0.27 deciview, 0.06 deciview, and 0.12 deciview,
respectively, at Wind Cave. Dyno-Nobel had an impact of 0.22
deciview at Rocky Mountain National Park. These sources' modeled
visibility impacts fell below the State's threshold of 0.5 deciview
and were determined not to be subject-to-BART. 78 FR 34747

Since the State's approach is consistent with the BART Guidelines \26\
and given the relatively limited impact on visibility from these seven
sources, as explained earlier in this document and in our proposals, we
are finalizing our proposal to approve Wyoming's threshold of 0.5
deciviews as reasonable for determining whether its BART-eligible
sources are subject-to-BART. 78 FR 34734, 34747
---------------------------------------------------------------------------

    \26\ 40 CFR part 51, appendix Y, section III.A.1.
---------------------------------------------------------------------------

    We do not agree that our decision exceeds our statutory authority
and the goals and objectives of the RHR. CAA section 110(a)(2)(J)
requires each plan submitted by a state to ``meet the applicable
requirements'' of Part C of Title I of the CAA, including those for
``visibility protection.'' In the case of a regional haze SIP
submittal, the ``applicable requirements'' include 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 . . .'' \27\ Section 169A(g)(2) further
provides that:
---------------------------------------------------------------------------

    \27\ 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 non-air 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.\28\
---------------------------------------------------------------------------

    \28\ 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 non-air 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.\29\
---------------------------------------------------------------------------

    \29\ 40 CFR 51.308(e)(1)(ii)(A).

Wyoming's BART determinations for NOX at five BART units
fall short of these requirements in several respects.
    First, Wyoming did not analyze the ``best system of continuous
emission control technology available and associated emission
reductions achievable.'' This is explained in detail in our proposed
rulemaking, the docket for this action, and elsewhere in this document.
Therefore, Wyoming 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.''
    For example, as we explained in our proposed notices and elsewhere
in this final action, Wyoming did not appropriately consider the
``degree of improvement in visibility which may reasonably be
anticipated'' from installation of BART because it did not provide
visibility improvement modeling from which the benefits of individual
NOX controls could be ascertained. Thus Wyoming's BART
determinations for NOX do not meet the requirements of CAA
section 169A(g)(2) or 40 CFR 51.308(e)(1)(ii)(A).
    Additionally, as explained in our proposed notices and elsewhere in
the modeling section of this final action, it was not possible to
ascertain the visibility improvement from the NOX control
options as the State modeled emission reductions for multiple
pollutants together. For this reason, in the modeling conducted by EPA,
we held SO2 and PM emission rates constant (reflecting the
``committed controls'' for those pollutants identified by Wyoming), and
varied only the NOX emission rate. This allowed us to
isolate the degree of visibility improvement attributable to the
NOX control option.
    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 part 51 (Guidelines for BART
Determinations under the Regional Haze Rule).
    All of the Wyoming BART sources, except Wyodak, 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, Wyoming's BART determinations for these sources
did not fully comply with the BART Guidelines. In particular, as
explained more fully elsewhere in this document, contrary to the
Guidelines' admonition that ``cost estimates should be based on the
CCM, where possible,'' the control cost calculations supplied by the
utilities and relied upon by Wyoming included costs not allowed by the
CCM, such as owner's costs and Allowance for Funds Utilized During
Construction (AFUDC). Thus, Wyoming's consideration of the ``cost of
compliance'' for these units was not consistent with the Guidelines.
Furthermore, as explained elsewhere in this document, Wyoming's
consideration of visibility benefits was inconsistent with the
Guidelines because the State did not provide visibility modeling from
which the visibility improvement from individual controls could be
ascertained. Finally, for all pollutants at all units covered by
today's action, Wyoming's regional haze SIP does not meet the
requirements of 40 CFR 51.308(e)(1)(iv) and (v) 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, the CAA and regional haze rule require that SIPs contain
provisions that make emissions limits, including BART limits,
practically enforceable. CAA section 110(a)(2)(A)-(B) require that
emissions limits such as BART be ``practically enforceable'' and SIPs
provide for establishment, methods and procedures necessary to monitor,
compile, and analyze data. CAA section 302(k) requires emissions limits
to be met on a continuous basis. Additionally, CAA section 169A(b)(2)
requires that regional haze SIPs include ``such emission limits,
schedules of compliance and other reasonable measures'' necessary to
meet the goals of the regional haze program.'' As discussed in our
proposed notices and elsewhere in this final notice, Wyoming'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, Wyoming's BART determinations for these five units
covered by the FIP do not meet the BART requirements of the CAA, the
RHR and the BART Guidelines. Additionally, Wyoming's SIP requirements
do not ensure the BART limits are enforceable for all BART sources for
which there is a SIP or FIP emissions limit, and therefore do not meet
the requirements of the CAA and RHR. Accordingly, we are compelled to
partially approve and partially disapprove Wyoming's regional haze SIP.
    Comment: EPA cannot invoke its Section 110 SIP approval authority
as grounds for rejecting state BART determinations with which it
disagrees. The CAA does not require any specific degree of visibility
improvement in the determination and only requires BART for the purpose
of eliminating or reducing impairment to visibility. See CAA Section
169A, 42 U.S.C. 7491.
    Consistent with the long-recognized principle that EPA may not
``condition approval of the plan of any State, on the State's adoption
of a specific control measure,'' Virginia, 108 F.3d at 1408, EPA has no
statutory authority to disapprove a SIP that contains a BART
determination for an individual facility that complies with the
statutory BART factors. Any other result would allow EPA to employ its
generalized SIP approval authority to ``run roughshod over the
procedural prerogatives that the Act has reserved to the States.''
Bethlehem Steel Corp., 742 F.2d at 1036.
    The fact that states must propose SIP revisions ``as may be
necessary'' to achieve reasonable progress does not mean EPA has
authority to countermand the textual commitment of specific BART
decisions to the states. The D.C. Circuit interpreted similar language
in Section 110(k)(5) to constrain EPA's authority over SIP approval and
disapproval. See Virginia, 108 F.3d at 1409. The SIP call provisions of
Section 110(k)(5) state that when a SIP is inadequate ``the
Administrator shall require the State to revise the plan as necessary
to correct such inadequacies.'' But the Virginia court rejected the
agency's expansive view of this phrase as authority to impose specific
control measures for specific emission sources.
    Response: States are required by the CAA to address the BART
requirements in their SIP. Our disapproval of the NOX BART
determinations in the Wyoming regional haze SIP is authorized under the
CAA because the State's NOX BART determinations for the five
units do not satisfy the statutory criteria. The State's analysis of
the cost effectiveness of controls and visibility analyses were flawed
due to reasons discussed elsewhere in the proposed and final notices.
While states have authority to exercise different choices in
determining BART, the determinations must be reasonably supported.
Wyoming's errors in taking into consideration the costs of compliance
were significant enough that we cannot conclude the State determined
BART according to CAA standards. The cases cited by the commenters
stress important limits on EPA authority in reviewing SIP submissions,
but our disapproval of these NOX BART determinations for the
five units has an appropriate basis in our CAA authority. We did not
require Wyoming to adopt specific control measures for specific
emission sources. Instead, we disapproved some of Wyoming's BART
determinations for reasons described in detail in our proposal and
elsewhere in our response to comments. To promulgate our FIP, EPA then
had both the authority and the duty to determine specific control
measures for specific sources.
    Finally, contrary to the commenter's assertion, the Bethlehem Steel
case is inapplicable here. We are promulgating BART emission
limitations and other FIP elements described elsewhere in this document
under the authority of CAA section 110(c), not through our action on
Wyoming's SIP. We have authority to promulgate our FIP under 110(c) on
two separate grounds: first, based on our January 2009 finding of
failure to submit the regional haze plan elements required by 40 CFR
51.309(g), the reasonable progress requirements for areas other than
the 16 Class I areas covered by the Grand Canyon Visibility Transport
Commission Report; and second, based on our partial disapproval of the
regional haze SIP.
    Comment: We received comments that EPA does not have the authority
under the CAA to issue a regional haze FIP in this instance. Commenters
contend that EPA's role under Section 110 in reviewing states' regional
haze SIPs is narrow and that the CAA confines EPA to the ministerial
function of reviewing SIPs for consistency with the CAA's requirements.
Commenters assert that Wyoming submitted a regional haze SIP that met
the requirements of Section 51.309 and included all the required
elements and that EPA admits that Wyoming has considered all five BART
factors. Therefore, commenters go on to say that EPA's sole function
was to review whether Wyoming followed the regional haze requirements,
including Appendix Y, in preparing the Wyoming regional haze SIP, and
Congress did not authorize EPA to ``second guess'' Wyoming's BART
decision making, or to substitute its own judgment, simply because EPA
would prefer different BART and reasonable progress NOX
controls. Commenters go on to point out that courts have consistently
held that states are primarily responsible for SIP development; EPA's
role is ministerial. Commenters cite that the Supreme Court has
recognized the states' primary role in developing SIPs, holding ``so
long as the ultimate effect of a State's choice of emission limitations
is in compliance with the national standards for ambient air, the State
is at liberty to adopt whatever mix of emission limitations it deems
best suited to its particular situation.'' Train v. NRDC, 421 U.S. 60,
79 (1975). Commenters argue that EPA is going beyond its ministerial
function of reviewing Wyoming's regional haze SIP for consistency with
the CAA's requirements; it is attempting to design Wyoming's SIP by
establishing new NOX emission limits, contrary to its
promulgated BART regulations. Commenters go on to say that EPA

should follow the structure of the CAA and give deference to the
State's judgment in determining BART in Wyoming's regional haze SIP.
    Response: States are required by the CAA to address the BART
requirements in their SIP. Our disapproval of the NOX BART
determinations in the Wyoming regional haze SIP is authorized under the
CAA because the State's NOX BART determinations for the five
units do not satisfy the statutory criteria. The State's analyses of
the cost effectiveness of controls and visibility analyses were flawed
due to reasons discussed in the introduction and BART sections of this
document. While states have the authority to exercise different choices
in determining BART, the determinations must be reasonably supported.
Wyoming's errors in taking into consideration the costs of compliance
and visibility analyses were significant enough that we cannot conclude
the State determined BART according to CAA standards. The cases cited
by the commenters stress important limits on EPA authority in reviewing
SIP submissions, but our disapproval of these NOX BART
determinations for the five units has an appropriate basis in our CAA
authority.
    Comment: Under the CAA, both the federal government and the states
have responsibilities for maintaining and improving air quality. The
federal government has the authority to set specific emissions targets,
but the states have the authority to develop and impose their own
regulatory structure to meet those. As long as the State meets its
specific criteria, which Wyoming can and will show that it has done,
the fact that EPA does not share the State's opinion regarding the best
course of action is immaterial.
    This reading of the CAA is the opinion of the Congress that passed
the regional haze program in 1977. Committee and floor debate in
Congress at the time makes clear that Congress fully intended for the
states to possess a high degree of primacy in regional haze decisions.
The primary sponsor of the CAA and 1977 amendments in the Senate was
the late Senator Edmund Muskie, a Democrat from Maine. In his opening
address to the Senate on the Conference Report to the 1977 amendments,
Senator Muskie said, ``under this legislation, the administrator of the
EPA will be more reliant on local and state capabilities to create the
institutional and infrastructural changes necessary to achieve clean
air. And perhaps this is as it should be. We have learned that there is
little political support for inartfully conceived national measures. We
have learned that where change can be made, it must be made with the
full understanding and support of the people who are affected by that
change.''
    While the courts in some instances may not give adequate weight to
the intent of Congress in drafting legislation, Congress's intent in
passing the nation's law is something that Congress itself takes very
seriously. Some courts have honored Congressional intent and upheld the
CAA as a cooperative statute. In Appalachia Power Company v. EPA [sic],
the courts determined that the CAA includes a cooperative standard they
call a federalism bar. In Train and Luminant Generation Co., LLC v.
EPA, 675 F.3d 917 (5th Cir. 2012) (hereinafter ``Luminant''), the
courts held that the EPA had no authority to overturn the decisions of
the states so long as the basic requirements of Section 110 are met.
    EPA does not have the authority under the CAA to issue a regional
haze FIP in this instance. EPA contends its review of the Wyoming SIP
is ``pursuant to section 110 of the CAA.'' 78 FR 34738. Section
110(a)(2) provides the general requirements that a SIP must contain.
Importantly, EPA's role under Section 110 in reviewing states' regional
haze SIPs is narrow: ``With regard to implementation, the (CAA)
confines the EPA to the ministerial function of reviewing SIPs for
consistency with the (CAA)'s requirements.'' Luminant Generation Co.,
LLC v. EPA, 675 F.3d 917, 921 (5th Cir. 2012) (citing section
110(k)(3)). As the court in Luminant explained, if the state's
submissions ``satisfy those basic requirements (found in section 110),
the EPA must approve them,'' and ``(t)hat is the full extent of the
EPA's authority in the SIP-approval process because that is all the
authority that the CAA confers.'' Id. at 932. Here, Wyoming submitted a
regional haze SIP that met the requirements of Section 309 and included
all the required elements. The Wyoming SIP submittals are well
developed and comprehensive. EPA admits that Wyoming considered all
five BART factors. 78 FR 34748. Therefore, EPA's role was to review
whether Wyoming followed the regional haze requirements, including
Appendix Y, and provided factual support for the Wyoming regional haze
SIP. Congress did not authorize EPA to ``second guess'' Wyoming's BART
decision making, or to substitute its own judgment, simply because EPA
would prefer different BART and reasonable progress NOX
controls.
    More recently, the D.C. Court vacated the CSAPR. The court's 2012
opinion in the CSAPR case is illustrative for our purposes because the
EPA used very similar arguments to justify their authority in CSAPR as
they're using today for regional haze. In vacating the CSAPR rule, the
D.C. Circuit Court writes ``under the CAA, the federal government sets
air quality standards, but states retain the primary responsibility for
choosing how to attain those standards within their borders. The Act
thus leaves it to the individual states to determine, in the first
instance, the particular restrictions that will be imposed on
particular emitters within their borders.'' The court goes on to write
that ``. . .the statutory federalism bar prohibits the EPA from using
the SIP process to force states to adopt specific control measures.''
    Response: We responded to similar comments above.\30\ With respect
to EPA's supposed admission that Wyoming considered the five BART
factors, the precise language in the proposal notice is: ``We find that
Wyoming considered all five steps above in its BART determinations, but
we propose to find that its consideration of the costs of compliance
and visibility improvement for the EGUs was inadequate and did not
properly follow the requirements in the BART Guidelines and statutory
requirements, as explained below.'' 78 FR 34748. With respect to the
legislative history quoted, the comment does not provide any connection
between the general remarks of Senator Muskie regarding the 1977
Amendments and EPA's interpretation of the visibility provisions in the
Act.
---------------------------------------------------------------------------

    \30\ As the commenter mentions, we agree that we did approve
Wyoming's regional haze SIP submitted under Section 309 of the RHR
(40 CFR 51.309) (77 FR 73926 (Dec. 12, 2012)), as in that action we
determined the State met the requirements of 40 CFR 51.309 and
related provisions.
---------------------------------------------------------------------------

    Comment: We received numerous general comments that EPA has
overstepped its authority and that states have the responsibility of
determining what controls are necessary for regional haze.
    Response: As explained earlier, the states have the responsibility
to draft the regional haze SIP and EPA has the responsibility of
ensuring state plans, including regional haze SIPs, conform to the CAA.
As the drafter of the regional haze SIP, the State generally has the
authority to decide how each of the BART factors are taken into account
and weighed. EPA is not disapproving Wyoming's BART determinations
because we disagree with how Wyoming weighed the relevant factors, such
as the cost of controls or the degree of visibility improvement
resulting from

the use of controls. EPA is disapproving certain Wyoming BART
determinations because the State did not consider these factors in its
BART determinations in accordance with the RHR and the Act.
    Comment: EPA's regional haze FIP failed to afford the required
deference to the technical, policy and other discretion granted to
Wyoming under the CAA and regional haze program. Congress added section
169A to the CAA in order to address the ``impairment of visibility'' in
Class I areas that ``results from man-made air pollution.'' This
provision of the CAA, in turn, describes separate roles for EPA, the
states, and major sources such as PacifiCorp's BART Units.
    EPA's roles are to create a report, see CAA section 169A(a)(2)-(3),
create regional haze regulations, see CAA section 169A(a)(4), provide
guidelines for the states, see CAA section 169A(b)(1), and determine
whether regional haze SIPs submitted by the states follow the
regulations and guidelines, and contain the required elements. CAA
section 110. The states' roles, which are central to the regional haze
program, are intended to be accomplished using substantial discretion
which, in turn, requires significant deference from EPA. States are
required to submit a regional haze SIP that contains ``emission limits,
schedules of compliance and other measures as may be necessary to make
reasonable progress toward meeting the national goal.'' CAA section
169A(b)(2). States also must ``determine[*thnsp;]'' BART for ``each
major stationary source.'' CAA 169A(b)(2)(A). BART sources, such as
PacifiCorp's BART units, are required to ``procure, install, and
operate (BART) as expeditiously as practicable.'' CAA section
169A(b)(2)(A).
    Thus, the CAA mandates that states have the primary role in
developing regional haze SIPs to protect visibility in Class I areas.
Likewise, the RHR makes clear that states have the responsibility to
create and implement regional haze SIPs. In contrast, EPA's role is to
develop ``guidelines'' for the states to use in implementing regional
haze SIPs and to determine whether states followed those guidelines.
CAA section 169A(b)(1). In short, the CAA anticipates that states,
using their discretion, develop regional haze SIPs using EPA
guidelines. This is exactly what Wyoming did in issuing BART permits
and developing the Wyoming regional haze SIP.
    In issuing regional haze guidelines, EPA recognized the broad
discretion granted to the states by the CAA. Specifically, EPA adopted
guidance to address BART determinations for certain large electrical
generating facilities, referred to as ``Appendix Y.'' EPA created
further guidance in the Federal Register responding to comments
concerning the then-proposed Appendix Y, referred to as the
``Preamble.'' EPA recognized in the Preamble that ``how states make
BART determinations or how they determine which sources are subject to
BART'' are among the issues ``where the Act and legislative history
indicate that Congress evinced a special concern with insuring that
states would be the decision makers.'' 70 FR 39104, 39137 (July 6,
2005).
    Likewise, in analyzing the applicability of certain executive
orders, EPA stated that ``ultimately states will determine the sources
subject to BART and the appropriate level of control for such sources''
and that ``states will accordingly exercise substantial intervening
discretion in implementing the final rule.'' Id. at 39155. The U.S.
Court of Appeals for the D.C. Circuit has affirmed that EPA's role
regarding regional haze programs is limited and that a state's role is
paramount. Indeed, the Court found that the CAA ``calls for states to
play the lead role in designing and implementing regional haze
programs.'' American Corn Growers Ass'n v. E.P.A., 291 F.3d 1, 2 (D.C.
Cir. 2002). The court also reversed a portion of EPA's original RHR
because it found that EPA's method of analyzing visibility improvements
distorted the statutory BART factors and was ``inconsistent with the
Act's provisions giving the states broad authority over BART
determinations.'' Id. at 8; (see also Utility Air Regulatory Group v.
EPA, 471 F.3d 1333, 1336 (D.C. Cir. 2006) (The second step in a BART
determination ``requires states to determine the particular technology
that an individual source `subject to BART' must install.'')). The
court in American Corn Growers emphasized that Congress specifically
entrusted states with making BART five-factor analysis decisions:
``[t]o treat one of the five statutory factors in such a dramatically
different fashion distorts the judgment Congress directed the states to
make for each BART-eligible source.'' American Corn Growers, 291 F.3d
at 6.
    The court in American Corn Growers also outlined the relevant
legislative history that recounts a specific agreement reached in
Congress which granted this authority to the states: ``The `agreement'
to which the Conference Report refers was an agreement to reject the
House bill's provisions giving EPA the power to determine whether a
source contributes to visibility impairment and, if so, what BART
controls should be applied to that source. Pursuant to the agreement,
language was inserted to make it clear that the states--not EPA--would
make these BART determinations. The Conference Report thus confirms
that Congress intended the states to decide which sources impair
visibility and what BART controls should apply to those sources. The
RHR attempts to deprive the states of some of this statutory authority,
in contravention of the Act.'' Id. at 8. EPA's FIP action makes the
same mistake and, if finalized, will be similarly reversible.
    In sum, based on the language in the CAA, the RHR, EPA's own
guidelines, and case law, the states have significant discretion when
creating regional haze SIPs.
    Response: We responded to similar comments above and elsewhere in
this document.
    Comment: EPA failed to properly account for that discretion in
analyzing the Wyoming regional haze SIP. EPA should have acknowledged
that the Wyoming regional haze SIP followed the law and was supported
by the facts. Examples of EPA ignoring Wyoming's discretion include:
Visibility improvement; cost effectiveness analysis; modeling;
application of the five BART factors; and reasonable progress analyses.
    Response: We responded to similar comments above and elsewhere in
this document.
    Comment: EPA's proposed action ignores the congressional commitment
to have local decisions under the CAA--particularly those relating to
BART--made by the states. States have the primary responsibility for
preventing air pollution under the CAA. CAA section 101(a)(3), 42
U.S.C. 7401(a)(3). Pursuant to this principle, states, not EPA, have
always had primary control over decisions to impose specific emission
limits (and therefore specific pollution control technologies) for
individual facilities. By congressional design, under the CAA EPA ``is
relegated . . . to a secondary role in the process of determining and
enforcing the specific, source-by-source emission limitations which are
necessary [to meet] national standards.'' Train v. NRDC, 421 U.S. 60,
79 (1975) (hereinafter ``Train''). This basic division of
responsibilities between EPA and the States remained unchanged when
Congress amended the Act in 1977 and again in 1990. See Virginia v.
EPA, 108 F.3d 1397, 1408-10 (D.C. Cir. 1997).
    Congress took this principle a step further under the regional haze
program, specifically directing that BART is to be

``determined by the State.'' CAA section 169A(b)(2)(A), 42 U.S.C.
section 7491(b)(2)(A). Congress adopted the BART provisions to address
visibility, rather than health concerns. See H.R. Rep. 95-294, at 529
(1977) (``It should be made clear at the outset that this provision
[concerning BART] is totally unrelated to any question involving public
health.'') (separate views of Messrs. Devine, Krueger, Broyhill,
Gammage, Clarence J. Brown, Collins, Moore and Stockman). Congress
therefore sensibly left decisions relating to the imposition of costly
visibility control technologies on certain existing sources entirely to
the states, where local factors could be properly considered and
implemented:

    The agreement clarifies that the state, rather than the
Administrator, identifies the source that impairs visibility in the
Federal class I areas. ``. . . In establishing emission limitations
for any source which impairs visibility, the State shall determine
what constitutes `best available retrofit technology' . . .'' H.R.
Conf. Rep. 95-564, at 155 (1977). While the original House bill
would have given EPA the power to determine what BART controls
should be applied to individual sources, Congress eventually
inserted the current statutory language to make it clear that the
States, rather than EPA, would make BART determinations. See id.; 5
Leg. History of CAA Amendments 1997 P.L. 95-95, H8663 (1997) (``The
provision [in the original bill] was modified to give States a
greater role in identifying sources which are contributing (or may
in the future contribute) to visibility problems and in establishing
control requirements for those sources.''). Senator Muskie confirmed
during the floor debate that ``the State, not the Administrator,
identifies a source that may impair visibility'' and that ``it is
the State which determines what constitutes `Best Available Retrofit
Technology.' '' 123 Cong. Rec. 26,854 (1977).

    The federal courts have enforced this legislative intent. In
American Corn Growers, the D.C. Circuit quoted at length from the
legislative history of section 169A to conclude that it was ``clear
that the States--not EPA--would make these BART determinations.'' 291
F.3d at 8; see also id. at 8 (``The Conference Report . . . confirms
that Congress intended the States to decide which sources impair
visibility and what BART controls should apply to those sources.'').
American Corn Growers reaffirms that the states have ``broad
authority'' to make their own BART determinations. Id. It also
reaffirms that EPA cannot ``deprive the states of some of this
statutory authority,'' nor can EPA ``constrain[ ] authority Congress
conferred on the states'' with respect to BART determinations. Id. at
8-9. It was for this reason that the court struck EPA's first attempt
at the Regional Haze Rule: it purported to tell the states how to make
BART determinations. Id. at 6-7. The same court later reiterated that
BART ``requires States to determine the particular technology that an
individual source `subject to BART' must install.'' Utility Air
Regulatory Grp. v. EPA, 471 F.3d 1333, 1336 (D.C. Cir. 2006).
    Other federal courts have recognized the cooperative federalism
policies on which the CAA in general--and the regional haze provisions
in particular--are based. See, e.g., Texas v. EPA, 690 F.3d 670, 684
(5th Cir. 2012); Ellis v. Gallatin Steel Co., 390 F.3d 461, 467 (6th
Cir. 2004); Sierra Club v. EPA, 315 F.3d 1295, 1300 (11th Cir. 2002);
Am. Lung Ass'n of N.J. v. Kean, 871 F.2d 319, 322 (3d Cir. 1989). Under
cooperative federalism, states retain the discretion and flexibility to
make their own choices based on local conditions, histories, and
policies. See, e.g., Budget Prepay, Inc. v. AT&T Corp., 605 F.3d 273,
281 (5th Cir. 2010) (`` `cooperative federalism' . . . necessarily
implies that states may reach differing conclusions on specific issues
relating to the implementation of the [statute]''); Global NAPs, Inc.
v. Mass. Dep't of Telecom. & Energy, 427 F.3d 34, 46 (1st Cir. 2005)
(cooperative federalism has ``the intended effect of leaving state
commissions free, where warranted, to reflect the policy choices made
by their states'' and to implement statutory provisions ``fairly and
with due regard to . . . local conditions . . . and . . . historical
circumstances''); Taylor v. Vt. Dep't of Educ., 313 F.3d 768, 777 (2d
Cir. 2002) (```[c]ooperative federalism . . . allows some substantive
differentiation among the states in the determination of which . . .
theories, practices, and approaches will be utilized''') (citation
omitted).
    In sum, Congress directed that BART determinations are to be made
by the states, allowing the states to make their own BART choices based
on local conditions and other considerations. Because EPA may not
exercise authority ``in a manner that is inconsistent with the
administrative structure that Congress enacted into law,'' ETSI
Pipeline Project v. Missouri, 484 U.S. 495, 517 (1998), EPA may not
disapprove a state BART determination that complies with the CAA,
whether or not EPA agrees with the state's decision. Here, EPA has not
demonstrated that Wyoming's BART determination violates the CAA, and
for that reason EPA must approve the BART determination in the SIP even
if it ``disagrees'' with it. Instead, just as in its rulemaking at
issue in Texas, EPA's Proposed Rule ``transgresses the CAA's delineated
boundaries of [the] cooperative relationship'' between EPA and the
states. 690 F.3d at 686. Response: EPA disagrees with this comment.
First, the legislative history of the 1977 Amendments cited by the
commenter is incomplete. The complete legislative history, when fairly
read, contradicts the commenter and confirms EPA's supervisory role in
reviewing state regional haze SIP submittals, including the state's
initial BART determinations.
    The 1977 Amendments resulted from a conference agreement that
reconciled the House bill, H.R. 6161, and the Senate bill, S. 252. The
conference committee agreed to adopt the visibility protection
provisions of section 116 of the House bill, with certain
modifications. With respect to the BART provision in what is now
section 169A(b)(2)(A) of the Act, the conference agreement inserted the
phrase ``as determined by the State (or the Administrator in the case
of a plan promulgated under [section 110(c) of the Act])'' in the two
places it now appears in that section.\31\ The conference agreement
inserted similar language into the definition of BART in section
169A(g)(2). The 1977 Amendments also added section 110(a)(2)(J) to the
Act, which makes (among other things) a regional haze SIP that meets
the requirements of part C relating to visibility protection a required
part of a state's SIP.
---------------------------------------------------------------------------

    \31\ The conference agreement also revised the language ``except
as otherwise provided pursuant to subsection (c), a requirement that
each major stationary source (as defined in section 302(o)) which is
in existence on the date of enactment of this section, but which has
not been in operation for more than 15 years as of such date'' in
H.R. 6161 to its present form. This revision does not affect any
issue raised by the commenter.
---------------------------------------------------------------------------

    Thus, H.R. 6161 required states to submit regional haze SIPs
containing BART determinations, but did not explicitly specify that the
BART determinations should, in the first instance, be made by the
state. The conference agreement language clarified that states should
make BART determinations as part of their SIP submittals, as explained
in the conference report:

    The agreement clarifies that the State, rather than the
Administrator, identifies the source that impairs visibility in the
Federal class I areas identified and thereby fall within the
requirements of this section. . . . In establishing emission
limitations for any source which impairs visibility, the State shall
determine what constitutes ``best available retrofit technology''
(as defined in this section) in establishing emission limitations on
a source-by-source basis to be included in the State implementation
plan so as to carry out the requirements of this section.

    H.R. Conf. Rep. 95-564, at 155 (1977) (emphasis added). In other
words, BART determinations are a required element (``the State shall
determine'') of a state's regional haze SIP submittal (``to be included
in the State implementation plan''). However, the conference report
does not say that the state's determination is final. For example, it
does not say: ``The State shall determine, and EPA shall abide by . .
.'' Thus, all the conference report says is that states must provide
BART determinations as part of the state's required regional haze
submittal. As the Tenth Circuit Court of Appeals stated, ``All the
conference agreement referenced by the D.C. Circuit did was shift the
initial responsibility for making BART determinations from the EPA to
the state. But that does not differ from other parts of the CAA--states
have the ability to create SIPs, but they are subject to EPA review.''
Oklahoma v. EPA, 723 F.3d 1201, 1209 (10th Cir. 2013).
    Another portion of the legislative history, only partially quoted
by the commenter, confirms EPA's supervisory role. Congressman Rogers
inserted into the Congressional Record a Clean Air Conference Report
(1977): Statement of Intent; Clarification of Select Principles. 123
Cong. Rec. 27070 (daily ed. Aug. 4, 1977) (statement of Cong. Rogers).
The Statement of Intent clarified ``some important points on the
intention and effect of the conferees action [that] may have been
overlooked or may be unclear in the text of the conference bill or the
accompanying statement of managers.'' Id. Under section ``D. Visibility
protection,'' the first full paragraph states:

    The conferees essentially agreed to the House provision for
visibility protection. The provision was modified to give States a
greater role in identifying sources which are contributing (or may
in the future contribute) to visibility problems and in establishing
control requirements for those sources. However, the conferees
rejected a motion to delete the national goal. The conferees also
rejected a motion to delete EPA's supervisory role under section 110
to assure that the required progress toward that goal will be
achieved by the revised State plan. If a State visibility protection
plan is not adequate to assure such progress, then the Administrator
must disapprove that portion of the SIP and promulgate a visibility
protection plan under section 110(c). Thus, visibility protection in
most mandatory federal Class I areas remains a national commitment,
which is nationally enforceable.

    Id. (emphasis added). Thus, the Statement of Intent, instead of
supporting the commenter's arguments, confirms EPA's supervisory role
over states' regional haze SIPs, as the conferees deliberately rejected
a proposal to remove that supervisory role.\32\ The Statement of Intent
also only describes states as having a ``greater role'' in determining
BART; it does not describe that role as exclusive.
---------------------------------------------------------------------------

    \32\ In context, the statement regarding ``required progress''
must be understood to include BART. First, the preceding portion of
the statement discusses States' roles in determining controls
generally under 169A(b)(2), ``including'' the BART requirements in
169A(b)(2)(A). The portion about EPA's supervisory role in assuring
``required progress'' should be understood to apply to all of
169A(b)(2), including subsection 169A(b)(2)(A).
---------------------------------------------------------------------------

    With respect to Senator Muskie's statements, the comment omits a
portion of the legislative history regarding application of the BART
Guidelines. Oklahoma v. EPA, 723 F.3d 1201, 1209-10 (10th Cir. 2013).
The Tenth Circuit considered those statements in context and confirmed
EPA's authority to ensure that state BART determinations for fossil-
fuel fired power plants having a total generating capacity greater than
750 MW complied with the BART Guidelines. Id. With respect to the
separate views of several Representatives regarding visibility
protection as unrelated to public health, those views are of a small
minority that opposed any provisions for visibility protection
whatsoever. H.R. Rep. 95-294, at 530 (1977). Their views did not carry
the day and, in any case, are irrelevant to the question of EPA's
supervisory role.
    With respect to the remainder of the comment regarding various
court opinions, we have responded to similar comments elsewhere. EPA's
action here violates neither the holdings in American Corn Growers and
UARG regarding the RHR, nor the generic remarks regarding cooperative
federalism in the other cited cases.
    Comment: Although EPA cites ``errors'' made by Wyoming in its BART
determination for Laramie River Station, EPA has not--and cannot--
demonstrate that any of these alleged ``errors'' represents a violation
of the CAA. These are technical disagreements over judgments committed
by Congress to the states--not grounds for EPA to step in and dictate a
technology choice. Section 169A does not confer any authority upon EPA
to make a BART determination when the state has made one. Once the
state makes a BART determination, EPA's authority to review it in the
SIP review process is very limited. Section 110 mandates that ``[EPA]
shall approve such [SIP] submittal as a whole if it meets all of the
applicable requirements of this chapter.'' 42 U.S.C. 7410(k)(3). See
also Forest Guardians v. Babbitt, 174 F.3d 1178, 1187 (10th Cir. 1999)
(``The Supreme Court and this circuit have made clear that when a
statute uses the word `shall,' Congress has imposed a mandatory duty
upon the subject of the command.'').
    As the Fifth Circuit recently expressed, ``the Act confines the EPA
to the ministerial function of reviewing SIPs for consistency with the
Act's requirements,'' and ``[t]h[e] statutory imperative [of section
110(k)(3)] leaves the agency no discretion to do anything other than
ensure that a state's submission meets the CAA's requirements and, if
it does, approve it.'' Luminant, 675 F.3d at 921, 926. See also id. at
932 (``If [the State's] regulations satisfy th[e] basic requirements
[of the CAA], the EPA must approve them, as section 7410(k)(3)
requires. That is the full extent of the EPA's authority in the SIP-
approval process because that is all the authority that the CAA
confers.'') Texas, 690 F.3d at 676 (``[I]f a SIP or a revised SIP meets
the statutory criteria of the CAA, then the EPA must approve it.'');
Bethlehem Steel Corp. v. Gorsuch, 742 F.2d 1028, 1036 (7th Cir. 1984)
(EPA's SIP disapproval power is ``constrained by the substantive
criteria in 42 U.S.C. 7410(a)(2)(A)-(K)''); Fla. Power & Light Co. v.
Costle,650 F.2d 579, 581 (5th Cir. 1981) (``If a SIP or a revised SIP
meets the statutory criteria. . . the EPA must approve it.'')
(citations omitted).
    Since Wyoming's BART decision for Laramie River Station, along with
its associated SIP revision, meets the requirements set forth in the
CAA, EPA has no discretion and must approve it in its entirety. As the
Supreme Court explained in the NAAQS context: The Act gives the Agency
no authority to question the wisdom of a state's choices of emission
limitations if they are part of a plan which satisfies the standards of
section 110(a)(2), and the Agency may devise and promulgate a specific
plan of its own only if a state fails to submit an implementation plan
which satisfies those standards. Section 110(c). Thus, so long as the
ultimate effect of a state's choice of emission limitations is
compliance with the national standards for ambient air, the state is at
liberty to adopt whatever mix of emission limitations it deems best
suited to its particular situation. Train, 421 U.S. at 79; see also
Virginia, 108 F.3d at 1408-10 (confirming that the 1977 Amendments to
section 110 did not alter the division of responsibilities recognized
in Train). Accord Union Elec. Co. v. EPA, 427 U.S. 246, 267 (1976)
(``[T]he State has virtually absolute power in allocating emission

limitations so long as national standards are met.'').
    The fact that states must propose SIP revisions ``as may be
necessary'' to achieve reasonable progress does not mean that EPA has
authority to countermand the textual commitment to leave BART decisions
to the states. The D.C. Circuit interpreted similar language in Section
110(k)(5) to constrain EPA's authority over SIP approval and
disapproval. See Virginia, 108 F.3d at 1409. The SIP call provisions of
Section 110(k)(5) similarly state that when a SIP is inadequate ``[EPA]
shall require the State to revise the plan as necessary to correct such
inadequacies.'' But the Virginia court rejected the agency's expansive
view of this phrase as authority to impose specific control measures
for specific emission sources: EPA apparently thinks the ``as
necessary'' language in section 110(k)(5) altered the division of
responsibilities between the states and the agency. We suppose the idea
is that because section 110(k)(5) empowers EPA to ``require the State
to revise the plan as necessary to correct'' inadequacies, it empowers
EPA to require the state to include particular control measures in the
revised plan.
    There is nothing to this. Id. at 1409. Instead, the court concluded
that this phrase ``keep[s] EPA within bounds.'' Id. at 1410. Imposition
of a FIP is intended to be a drastic penalty, imposed only where a
state fails to provide the air pollution reductions required by the
CAA, as ``it rescinds state authority to make the many sensitive and
policy choices that a pollution control regime demands.''' Id. at 1406-
07 (citation omitted). The court also expressed, in rejecting EPA's
interpretation of Section 110(k)(5), that ``[w]e would have to see much
clearer language to believe a statute allowed a federal agency to
intrude so deeply into state political processes.'' Id. at 1410.
    EPA must therefore approve the Wyoming SIP as it relates to BART at
Laramie River Station, as compliance with the law is all that is
required. See Luminant, 675 F.3d at 926 (EPA's reliance on factors
other than compliance with the CAA in disapproving a SIP violated the
Administrative Procedures Act (APA), as it was ``in excess of statutory
authority,'' and was arbitrary and capricious, as it considered ``a
`factor[ ] which Congress has not intended [the EPA] to consider' '')
(quoting 5 U.S.C. 706(2)(C) and State Farm, 463 U.S. at 43) (alteration
in original).
    Response: EPA is not substituting its judgment on required
technology for the State's in this decision. Rather, we have determined
that Wyoming's analysis and determinations were not performed
consistent with the CAA and implementing regulations. EPA considered
the State's SIP as well as the most recent information submitted by
Basin Electric and others for the Laramie River BART units. As
explained in detail in our response to similar comments in the BART
section of this document, we found Basin Electric's estimates of SCR
capital cost deficient in a number of respects, specifically: (1)
Inadequate explanation for the high labor rates that were assumed when
compared to published labor rates; (2) High overtime and per diem costs
without sufficient explanation; (3) Apparent duplication of costs
associated with General Facilities; (4) Inclusion of AFUDC; (5)
Apparent duplication of contingencies and other cost adders; and (6)
Addition of unnecessary SO3 mitigation system. All of these
contributed to excessively high capital cost. Sargent & Lundy also
assumed excessively high cost for replacement catalyst, which
contributes to high operating cost. As we explain elsewhere, these
deficiencies are inconsistent with the CAA and RHR.
    We responded to similar comments regarding the remaining comments
above and elsewhere in this document.
    Comment: To the extent that the Supreme Court in ADEC suggested it