--------------------------------------------------------------------------------------------------------------------------------------------------------
Fabric Filter--Unit 1.........................................              73.2             0.015               299        $3,436,594           $11,494
Fabric Filter--Unit 2.........................................              76.6             0.015               464         4,101,705             8,848
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The State did not provide visibility improvement modeling for
fabric filters, but EPA is proposing to conclude this is reasonable
based on the high cost effectiveness of fabric filters at each of the
units, which is higher than EPA or other State have considered
reasonable for PM BART.
    Based on its consideration of the five factors, the State
determined that the existing ESPs with FGC were reasonable for PM BART
for Units 1 and 2. The State determined that fabric filters were not
reasonable based on the high cost effectiveness. The State determined
that the PM BART emission limits for Naughton Unit 1 are 0.04 lb/MMBtu,
74 lb/hr, and 324 tpy and the PM BART emission limits for Naughton Unit
2 are 0.04 lb/MMBtu, 96 lb/hr, and 421 tpy. The State determined the PM
BART emission limits for Naughton Unit 3 are 0.015 lb/MMBtu, 56 lb/hr,
and 243 tpy.
    We agree with the State's conclusions, and we are proposing to
approve its BART determination for Naughton Units 1, 2, and 3.
vii. PacifiCorp Wyodak--Unit 1
Background
    PacifiCorp Wyodak Power Plant is located in Campbell County,
Wyoming. Wyodak Power Plant is comprised of one coal-fired boiler, Unit
1, burning pulverized sub-bituminous Powder River Basin coal for a
total net generating capacity of a nominal 335MW. Wyodak's boiler
commenced service in 1978. The State's BART determination can be found
in Chapter 6.5.7 and Appendix A of the SIP (The NOX BART
analysis for Wyodak Unit 1 is discussed in Section VII.A of this
notice).
PM BART Determination
    Wyodak Unit 1 is currently controlled with fabric filters with an
emission limit of 0.015 lb/MMBtu (30-day rolling average). The State
determined that fabric filters on Wyodak Unit 1 represent the most
stringent PM control technology and that 0.015 lb/MMBtu represents the
most stringent emission limit. Consistent with the BART Guidelines, the
State did not provide a full five-factor analysis because the State
determined BART to be the most stringent control technology and limit.
The State determined the PM BART emission limits for Wyodak Unit 1 are
0.015 lb/MMBtu, 71.0 lb/hr, and 308.8 tpy.
    We agree with the State's conclusions, and we are proposing to
approve its PM BART determination for Wyodak Unit 1.

D. Reasonable Progress Requirements

    In order to establish RPGs for its Class I areas, and to determine
the controls needed for the LTS, Wyoming followed the process
established in the RHR. Wyoming identified sources (other than BART
sources) and source categories in Wyoming that are major contributors
to visibility impairment and considered whether these sources should be
controlled based on a consideration of the factors identified in the
CAA and EPA's regulations (see CAA 169A(g)(1) and 40 CFR
51.308(d)(1)(i)(A)). Wyoming then identified the anticipated visibility
improvement in 2018 in all its Class I areas using the WRAP Community
Multi-Scale Air Quality (CMAQ) modeling results.
1. Visibility Impairing Pollutants and Sources
    In order to determine the significant sources contributing to haze
in Wyoming's Class I areas, Wyoming relied upon two source
apportionment analysis techniques developed by the WRAP. The first
technique was regional modeling using the Comprehensive Air Quality
Model (CAMx) and the PM Source Apportionment Technology (PSAT) tool,
used for the attribution for sulfate and nitrate sources only. The
second technique was the Weighted Emissions Potential (WEP) tool, used
for attribution of sources of OC, EC, PM2.5, and
PM10. The WEP tool is based on emissions and residence time,
not modeling and looks at all sources throughout the modeling domain.
    PSAT uses the CAMx air quality model to simulate nitrate-sulfate-
ammonia chemistry and apply this chemistry to a system of tracers or
``tags'' to track the chemical transformations, transport, and removal
of NOX and SO2. These two pollutants are
important because they tend to originate from anthropogenic sources.
Therefore, the results from this analysis can be useful in determining
contributing sources that may be controllable, both in-state and in
neighboring states.
    WEP is a screening tool that helps to identify source regions that
have the potential to contribute to haze formation at specific Class I
areas. Unlike PSAT,

this method does not account for chemistry or deposition. The WEP
combines emissions inventories, wind patterns, and residence times of
air masses over each area where emissions occur, to estimate the
percent contribution of different pollutants. Like PSAT, the WEP tool
compares baseline values (2000-2004) to 2018 values, to show the
improvement expected by 2018 for OC, EC, PM2.5, and
PM10. More information on the WRAP modeling methodologies is
available in the document Technical Support Document for Technical
Products Prepared by the Western Regional Air Partnership (WRAP) in
Support of Western Regional Haze Plans in the Supporting and Related
Materials section of the docket. Table 15 shows Wyoming's contribution
to extinction at its own Class I areas.
---------------------------------------------------------------------------

    \21\ Extinction and species contribution to total particulate
extinction taken from IMPROVE data (http://vista.cira.colostate.edu/dev/web/AnnualSummaryDev/Composition.aspx). IMPROVE data for NOABI
based on available data for 2002-2004. Contribution of sulfate and
nitrate based on PSAT; OC, EC, PM2.5, and PM10
contribution based on WEP as taken from the WRAP TSS (http://vista.cira.colostate.edu/tss/).

               Table 15--Wyoming Sources Extinction Contribution 2000-2004 for 20% Worst Days \21\
----------------------------------------------------------------------------------------------------------------
                                                                                Species        Wyoming Sources
                                                                              Contribution to    Contribution to
            Class I Area              Pollutant Species   Extinction (Mm-1)  Total Particulate       Species
                                                                               Extinction (%)    Extinction (%)
----------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand     Sulfate............               4.3               16.7                5.9
 Teton National Park, Teton
 Wilderness.
                                     Nitrate............               1.8                7.0                4.7
                                     OC.................              13.5               52.4               72.6
                                     EC.................               2.5                9.7               66.8
                                     Fine PM............               1.0                3.9               24.0
                                     Coarse PM..........               2.6               10.1               20.0
                                     Sea Salt...........               0.02               0.08  ................
North Absaroka Wilderness, Washakie  Sulfate............               4.9               20.7                5.6
 Wilderness.
                                     Nitrate............               1.6                6.8                8.2
                                     OC.................              11.6               48.9               44.6
                                     EC.................               1.9                8.0               39.5
                                     Fine PM............               0.8                3.4               14.0
                                     Coarse PM..........               2.9               12.2               12.1
                                     Sea Salt...........  .................               0.04  ................
Bridger Wilderness, Fitzpatrick      Sulfate............               5.0               22.2               15.4
 Wilderness.
                                     Nitrate............               1.4                6.2               19.4
                                     OC.................              10.5               46.6               58.5
                                     EC.................               2.0                8.9               51.0
                                     Fine PM............               1.1                4.9               30.3
                                     Coarse PM..........               2.5               11.1               27.4
                                     Sea Salt...........               0.04               0.2   ................
----------------------------------------------------------------------------------------------------------------

    Table 16 shows influences from sources both inside and outside of
Wyoming per the PSAT modeling for 2018. As indicated, the outside
domain (OD) region is the highest contributor to sulfate and nitrate at
all Wyoming Class I areas. The outside domain region represents the
concentration of pollutants at the boundaries of the modeling domain.
Depending on meteorology and the type of pollutant (particularly
sulfate), these emissions can be transported great distances from
regions such as Canada, Mexico, and the Pacific Ocean. Wyoming is the
second highest contributor of particulate sulfate and nitrate at
Bridger and Fitzpatrick Wilderness areas, but is a lesser contributor
at the other Class I areas.
---------------------------------------------------------------------------

    \22\ OD denotes Outside Domain; ID denotes Idaho, MT denotes
Montana, CAN denotes Canada, UT denotes Utah, WA denotes Washington,
WY denotes Wyoming, CA denotes California, and OR denotes Oregon.

                                           Table 16--PSAT Source Region Apportionment for 20% Worst Days \22\
--------------------------------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------------------------------
                  Class I Area                                                              2018 Sulfate PSAT
                                                                       2018 Nitrate PSAT
--------------------------------------------------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand Teton National  Region...........................     OD     ID     WY    CAN     OR     OD     ID     WA     UT     OR
 Park, Teton Wilderness.                         % Contribution...................   46.5    8.1    5.8    5.4    4.6   31.3   28.2    9.4    7.4    7.0
North Absaroka Wilderness, Washakie Wilderness.  Region...........................     OD    CAN     MT     ID     WY     OD     ID     MT    CAN     WY
                                                 % Contribution...................   50.1   12.5    6.5    5.7    5.5   30.7   16.7   14.8   11.5    8.2
Bridger Wilderness, Fitzpatrick Wilderness.....  Region...........................     OD     WY     ID     UT    CAN     OD     WY     UT     ID     CA
                                                 % Contribution...................   31.1   15.3    7.6    5.9    5.1   21.8   19.3   15.6   10.6    6.8
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Tables 17 shows the WEP contribution for EC, OC, PM2.5,
and PM10.

                          Table 17--WEP Source Category Contribution for 20% Worst Days
----------------------------------------------------------------------------------------------------------------
                                                                                Anthropogenic   Natural Fires
          Class I Area                 Point           Area           Mobile           Fires       and Biogenic
----------------------------------------------------------------------------------------------------------------
                                                       OC
----------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand           0.408           3.892           1.636           8.303          85.764
 Teton National Park, Teton
 Wilderness.....................
North Absaroka Wilderness,                 0.661           9.449           2.844          11.881          75.159
 Washakie Wilderness............
Bridger Wilderness, Fitzpatrick            0.984           7.552           3.28            7.644          80.543
 Wilderness.....................
----------------------------------------------------------------------------------------------------------------
                                                       EC
----------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand           0.243           2.628          13.659           5.51           77.958
 Teton National Park, Teton
 Wilderness.....................
North Absaroka Wilderness,                 0.386           5.755          23.253           7.054          63.55
 Washakie Wilderness............
Bridger Wilderness, Fitzpatrick            0.54            4.509          25.65            4.105          65.195
 Wilderness.....................
----------------------------------------------------------------------------------------------------------------
                                                      PM2.5
----------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand           5.565          70.463           0.086           5.469          18.411
 Teton National Park, Teton
 Wilderness.....................
North Absaroka Wilderness,                 3.491          86.311           0.171           3.334           6.691
 Washakie Wilderness............
Bridger Wilderness, Fitzpatrick           16.311          69.195           0.081           3.618          10.785
 Wilderness.....................
----------------------------------------------------------------------------------------------------------------
                                                      PM10
----------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand           2.655          83.939           0.363           0.717          12.316
 Teton National Park, Teton
 Wilderness.....................
North Absaroka Wilderness,                 2.066          93.197           0.213           0.313           4.206
 Washakie Wilderness............
Bridger Wilderness, Fitzpatrick            6.775          84.157           0.477           0.353           8.23
 Wilderness.....................
----------------------------------------------------------------------------------------------------------------

    Table 17 shows that EC, OC, PM2.5 and PM10
emissions come mainly from sources such as natural fire, windblown
dust, and road dust. To select the sources that would undergo the
required four factor analysis, Wyoming looked at State emission
inventory data in conjunction with the source apportionment information
discussed above (a summary of the State's emission inventory can be
found in section VI.E.1 of this notice). After evaluating this
information, the State determined that stationary source emissions of
NOX and SO2 were reasonable to evaluate for
purposes of reasonable progress controls. The State also determined
that emissions of NOX from oil and gas development should be
analyzed for purposes of reasonable progress. Since emissions of OC,
EC, PM2.5, and PM10 come from mainly
uncontrollable sources, the State determined it was reasonable to not
evaluate these pollutants for reasonable progress controls. The State
submitted a January 12, 2011, SIP that addresses sources of
SO2.\23\ Thus, the State evaluated emissions of the
remaining pollutant, NOX, for reasonable progress in this
SIP.
---------------------------------------------------------------------------

    \23\ The State submitted a January 12, 2011 SIP submittal to
address the requirements under 40 CFR 51.309, with the exception of
the 40 CFR 51.309(g) requirements addressed in this SIP submittal.
---------------------------------------------------------------------------

2. Four Factor Analysis
    In determining the measures necessary to make reasonable progress,
States must take into account the following four factors and
demonstrate how they were taken into consideration in selecting
reasonable progress goals for a Class I area:
     Costs of Compliance;
     Time Necessary for Compliance;
     Energy and Non-air Quality Environmental Impacts of
Compliance; and
     Remaining Useful Life of any Potentially Affected Sources.
    CAA Sec.  169A(g)(1) and 40 CFR 308(d)(1)(i)(A).
    The State performed a four factor analysis for each of the
reasonable progress sources pursuant to 40 CFR 51.308(d)(1)(i)(A).
a. Stationary Sources
    The State used a reasonable progress screening methodology termed
``Q/d'' to determine which stationary sources would be candidates for
controls under reasonable progress. Q/d is a calculated ratio where Q
represents (in this case) the NOX emission rate in tpy of
the source divided by the distance in kilometers of the point source
from the nearest Class I area, denoted by ``d.'' The State used the
maximum permitted emission rate for each source to determine the tpy of
NOX it used in the Q/d calculation. The State determined
that a Q/d value of 10 is reasonable for determining which sources the
State should consider for reasonable progress controls, since this
value yielded sources of concern similar in magnitude to sources
subject-to-BART.
    The State determined there were three units with a Q/d of greater
than 10 that are not already being controlled under BART and the State
completed a reasonable progress analysis for each of the sources. The
sources are PacifiCorp Dave Johnson Unit 1 and Unit 2 and Mountain
Cement Company Laramie Plant kiln. Dave Johnston Units 1 and 2 is
addressed as part of our FIP in section VII.B of this notice. In
addition, as previously mentioned, the State considered reasonable
controls on oil and gas development sources.
b. Summary of Reasonable Progress Determinations and Limits
    For the subject-to-reasonable progress sources, the State provided
analyses that took into consideration the four factors as required by
section 169A(g)(1) of the CAA and 40 CFR 51.308(d)(1)(i)(A). For the
stationary sources, the State relied on the analysis found in
Supplementary Information for Four-Factor Analyses for Selected
Individual Facilities in Wyoming, May 6, 2009, Revised Draft Report
Prepared by EC/R Incorporated. For oil and gas sources, the State
relied on the analysis found in Supplementary Information for Four
Factor Analyses by WRAP States, May 4, 2009 (Corrected 4/

20/10) Revised Draft Report Prepared by EC/R Incorporated (for a
complete copy of the reports see Chapter 7 of the State's TSD). The
analyses considered EPA's BART Guidelines as relevant to their
reasonable progress evaluations, as well as EPA's Guidance for Setting
Reasonable Progress Goals Under the Regional Haze Program.
    In this action, EPA is proposing to approve the reasonable progress
NOX determinations submitted by the State for oil and gas
sources and for Mountain Cement Company Laramie Plant kiln. EPA is
proposing to disapprove the State's reasonable progress determinations
and proposing to issue a reasonable progress determination
NOX FIP for PacifiCorp Dave Johnston Unit 1 and Unit 2.
EPA's rationale for disapproving the State's reasonable progress
determination for these units, as well as EPA's reasonable progress FIP
determination, can be found in section VII.B of this notice.
    A summary of the reasonable progress analysis and determination for
each source/source category that we are proposing to approve is
provided below.
i. Oil and Gas Area Sources
Background
    Oil and gas exploration and production is occurring in numerous
areas in Wyoming. The sources associated with oil and gas production
mainly emit NOX and VOCs; in this context, the State
considered NOX. Oil and gas production and exploration
includes operation, maintenance, and servicing of production
properties, including transportation to and from sites. EC/R evaluated
reasonable progress control technologies for common sources in the oil
and gas industry including compressor engines, turbines, process
heaters, and drilling rig engines. The State's NOX
reasonable progress determination for oil and gas sources can be found
in Chapter 7.3.5 of the SIP.
NOX Reasonable Progress Determination
    For compressor engines, potential control options identified by the
State include air-fuel ratio controls (AFRC), ignition timing retard,
low-emission combustion (LEC) retrofit, SCR, SNCR, and replacement with
electric motors. The State evaluated several control technologies for
drilling rig engines including ignition timing retard, exhaust gas
recirculation (EGR), SCR, replacement of Tier 2 engines with Tier 4
engines, and diesel oxidation catalyst. Potential controls for turbines
identified by the State include water or steam injection, LNBs, SCR,
and water or steam injection with SCR. NOX emission control
technologies identified by the State for process heaters include LNBs,
ultra-low NOX burners (ULNBs), LNBs with flue gas
recirculation (FGR), SNCR, SCR, and LNBs installed in conjunction with
SCR.
    NOX emissions vary based on the equipment and fuel
source. Emissions from individual natural gas-fired turbines at
production operations can be as high as 877 tpy of NOX,
while emissions from individual natural gas turbines at exploration
operations can reach 131 tpy of NOX. Individual gas
reciprocating engines have comparable NOX emissions with up
to 700 tpy at production operations and 210 tpy at exploration
operations. Diesel engine emissions can approach 46 tpy for production
operations and 10 tpy for exploration operations.
    Table 18 provides a summary of the reasonable progress
NOX analysis for oil and gas sources. Both the capital and
annual costs for each technology is dependent on the engine size or on
the process throughput; therefore, for most of the control technologies
listed in Table 18, the State has provided cost estimate ranges. The
lower end of the cost/ton estimates represent the cost per unit for
larger or higher production units, while the higher end of the cost/ton
estimates represent the cost per unit for the smaller or lower
production units.

                       Table 18--Summary of Reasonable Progress NOX Analysis for Oil and Gas Exploration and Production Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Estimated                        Estimated
                                                             Control         Pollutant        Capital    Annual Cost                           Cost
            Source Type               Control Technology    Efficiency      Controlled        Cost ($/     ($/year/          Units         Effectiveness
                                                               (%)                             unit)        unit)                             ($/ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Compressor Engines................  AFRC.................        10-40  NOX...............       5.3-42      0.9-6.8  hp................        68-2,500
                                    Ignition timing              15-30  NOX...............          N/A          1-3  hp................        42-1,200
                                     retard.
                                    LEC retrofit.........        80-90  NOX...............      120-820       30-210  hp................       320-2,500
                                    SCR..................           90  NOX...............      100-450       40-270  hp................      870-31,000
                                    SNCR.................        90-99  NOX...............        17-35          3-6  hp................           16-36
                                    Replacement with               100  NOX...............      120-140        38-44  hp................       100-4,700
                                     electric motors.
Drilling Rig Engines and Other      Ignition timing              15-30  NOX...............       16-120        14-66  hp................     1,000-2,200
 Engines.                            retard.                        40  NOX...............          100        26-67  hp................       780-2,000
                                    EGR..................        80-95  NOX...............    100-2,000     40-1,200  hp................     3,000-7,700
                                    SCR..................
                                    Replacement of Tier 2           87  NOX...............          125           20  hp................       900-2,400
                                     engines with Tier 4.
Turbines..........................  Water or steam               68-80  NOX...............       4.4-16          2-5  1000 BTU..........       560-3,100
                                     injection.
                                    LNB..................        68-84  NOX...............         8-22      2.7-8.5  1000 BTU..........    2,000-10,000
                                    SCR..................           90  NOX...............        13-34       5.1-13  1000 BTU..........     1,000-6,700
                                    Water or steam               93-96  NOX...............        13-34       5.1-13  1000 BTU..........     1,000-6,700
                                     injection with SCR.
Process Heaters...................  LNB..................           40  NOX...............      3.8-7.6    0.41-0.81  1000 BTU..........     2,100-2,800
                                    ULNB.................        75-85  NOX...............       4.0-13     0.43-1.3  1000 BTU..........     1,500-2,000
                                    LNB and FGR..........           48  NOX...............           16          1.7  1000 BTU..........           2,600
                                    SNCR.................           60  NOX...............        10-22      1.1-2.4  1000 BTU..........     4,700-5,200
                                    SCR..................        70-90  NOX...............        33-48      3.7-5.6  1000 BTU..........     2,900-6,700
                                    LNB and SCR..........        70-90  NOX...............        37-55        4-6.3  1000 BTU..........     2,900-6,300
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Wyoming states that it would need up to two years to develop the
necessary regulations to control oil and gas sources.\24\ The State
estimated that companies would require a year to procure the necessary
capital to purchase the control equipment. The time required to design,
fabricate, and install control technologies will vary based on the
control technology selected and other factors.
---------------------------------------------------------------------------

    \24\ For all reasonable progress sources, the time necessary to
develop regulations is not a consideration under the time necessary
for compliance factor. If regulations are needed to implement
reasonable progress controls, the State must develop them as part of
the regional haze SIP.
---------------------------------------------------------------------------

    The State determined that no additional controls for oil and gas
sources were reasonable at this time. The State concluded that
emissions from large stationary sources processing oil and gas in the
WRAP region have been well quantified over the years, while smaller
exploration and production sources that the State is evaluating for
reasonable progress have not had the same degree of emission inventory
development. The State points out that understanding the sources and
volume of emissions at oil and gas production sites is necessary to
recognizing the impact that these emissions have on visibility.
    To better understand the emissions from stationary and mobile
equipment operated as part of oil and gas field operations, the WRAP
has been working on developing an emission inventory to more fully
characterize the oil and gas field operations emissions. The WRAP's
development of a more comprehensive emission inventory is still in
process (as of the date of the State's SIP submittal). The State
determined it cannot complete the evaluation of oil and gas on
visibility until the WRAP emission inventory study has been completed.
    The State points out that in the case of compressor engines, many
facilities have already installed control equipment.\25\ For lean burn
engines, oxidation catalysts are commonly installed, while SNCR with
AFRC are commonly installed for rich burn engines. The State also
points out that regulating drill rig engines can be problematic since
drill rig engines are, for the most part, considered mobile sources and
emission limits for mobile sources are set by the Federal government
under section 202 of the CAA.
---------------------------------------------------------------------------

    \25\ Oil and gas sources are regulated by the State as part of
its minor source BACT requirements in Wyoming Air Quality Standards
and Regulations Chapter 6, Section 2.
---------------------------------------------------------------------------

    We disagree with the State's reasoning for not adopting reasonable
progress controls for oil and gas sources. If the State determined that
additional information was needed to potentially control oil and gas
sources, the State should have developed the information. While we
disagree with the State's reasoning for not requiring any controls
under reasonable progress, we are proposing to approve the State's
conclusion that no additional NOX controls are warranted for
this planning period. As shown by the four factor analyses, the most
reasonable controls are for compressor engines, which the State already
controls through its minor source BACT requirements (see above). In
addition, while the costs of some controls are within the range of cost
effectiveness values Wyoming, other states, and we have considered as
reasonable in the BART context, they are not so low that we are
prepared to disapprove the State's conclusion in the reasonable
progress context.
    We are proposing to approve the State's reasonable progress
determination for oil and gas sources.
ii. Mountain Cement Company Laramie Plant--Kiln
Background
    The Mountain Cement Company Laramie Plant cement kiln is a long dry
kiln with a capacity of 1,500 tons of clinker per day. Assuming the
plant runs 365 days of the year, the result is 547,500 tpy of clinker.
NOX Reasonable Progress Determination
    The kiln is currently uncontrolled for NOX emissions.
The State determined that indirect and direct firing of LNBs, biosolid
injection, NOxOUT \SM\, CemSTAR \SM\, LoTOx TM, SCR, SNCR
(using urea), and SNCR (using ammonia) were technically feasible for
controlling NOX emissions from the kiln. The State did not
identify any technically infeasible controls.
    The State did not identify any energy or non-air quality
environmental impacts that would preclude the selection of any of the
controls evaluated, and there are no remaining-useful-life issues for
this source. A summary of the State's NOX reasonable
progress analyses for the kiln is provided in Table 19 below. Baseline
NOX emissions for the kiln are 524 tpy based on 2002 actual
emissions.
---------------------------------------------------------------------------

    \26\ A negative annual cost is given because cement kilns
receive a credit for the biosolids tipping fee paid by facilities
providing the biosolids to the cement plant. For the purposes of
this analysis, the tipping fee is $5.00/ton.
    \27\ Cost effectiveness figures for the CemStar\SM\ process were
not available for dry kilns.
    \28\ Cost effectiveness figures for LoTOx TM were not
available for dry kilns.
    \29\ Capital and annual costs for SNCR have only been costed for
preheater and precalcnier kilns. Only cost effectiveness figures
were available for dry kilns.

               Table 19--Summary of Mountain Cement Company Kiln NOX Reasonable Progress Analysis
----------------------------------------------------------------------------------------------------------------
                                                                                Cost
         Control Technology                Control            Emission      Annualized  Costs  Effectiveness  ($/
                                       Efficiency  (%)    Reduction (tpy)                             ton)
----------------------------------------------------------------------------------------------------------------
LNB (indirect)......................              30-40            157-210           $205,000       $6,568-4,910
LNB (direct)........................                 40                210            449,000             13,853
Biosolid Injection \26\.............                 50                262           -127,000              1,324
NOxOUT \SM\.........................                 35                183            507,000              8,023
CemSTAR \SM\ \27\...................              20-60            105-314            Unknown            Unknown
LoTOxTM \28\........................              80-90            419-472            Unknown            Unknown
SCR.................................                 80                419          7,553,000             82,535
SNCR (urea) \29\....................                 35                183            Unknown              1,223
SNCR (ammonia)......................                 35                183            Unknown              1,223
----------------------------------------------------------------------------------------------------------------

    The State estimated that it could potentially take seven years to
install control equipment on the kiln. This estimate includes the two
years that will be necessary for the State to implement new regulations
and the one-year Mountain Cement will likely need to obtain the
necessary capital for the purchase of new emission control technology.
The State estimates the total time necessary for compliance will vary
based on the control technology selected. For example, the State
predicts that one and a half years will be required to design,
fabricate, and install

SCR or SNCR technology, while over two and a half years will be
required to design, fabricate, and install LoTOx \TM\ technology.
    The State determined no controls were reasonable for reasonable
progress for Mountain Cement Company Laramie Plant kiln. The State
cited that the four-factor analysis was limited, in that no guidance
was provided by EPA for identifying significant sources and EPA did not
establish contribution to visibility impairment thresholds (a potential
fifth factor for reasonable progress determinations).\30\ The State
further claims that the State cannot, per Wyoming Statute 35-11-202,
establish emission control requirements except through State rule or
regulation. Furthermore, the Wyoming statute requires the State to
consider the character and degree of injury of the emissions involved.
In this case, the State claims it would need to have visibility
modeling that assessed the degree of injury caused by the emissions,
which the State does not have. The State believes it has taken a strong
and reasonable first step in identifying potential contributors to
visibility impairment, and that the next step of creating an
appropriate rule or regulation will be accomplished in the next SIP
revision.
---------------------------------------------------------------------------

    \30\ States must consider the four factors as listed above but
can also take into account other relevant factors for the reasonable
progress sources identified (see EPA's Guidance for Setting
Reasonable Progress Goals under the Regional Haze Program, (``EPA's
Reasonable Progress Guidance''), p. 2-3, July 1, 2007).
---------------------------------------------------------------------------

    We disagree with the State's reasoning for not adopting reasonable
progress controls for Mountain Cement Company Laramie Plant kiln. If
the State determined that it needed to adopt a rule or perform modeling
to adequately assess and, if warranted, require reasonable progress
controls, the State should have completed these steps before it
submitted its regional haze SIP. The RHR does not allow for commitments
to potentially implement strategies at some later date that are
identified under reasonable progress or for the State to take credit
for such commitments. Nor does it allow the State to consider the time
to promulgate regulations as part of the time for compliance.
    While we disagree with the State's reasoning for not requiring any
controls under reasonable progress, we are proposing to approve the
State's conclusion that no additional NOX controls are
warranted for this planning period. While the costs of some controls
(i.e., biosolid injection and SNCR) are within the range of cost
effectiveness values Wyoming, other states, and we have considered as
reasonable in the BART context, they are not so low that we are
prepared to disapprove the State's conclusion in the reasonable
progress context. In addition, these controls afford relatively modest
emission reductions.
3. Reasonable Progress Goals
    40 CFR 51.308(d)(1) requires states to ``establish goals'' (in
deciviews) that provide for reasonable progress towards achieving
natural visibility conditions for each Class I area of the State. These
RPGs are interim goals that must provide for incremental visibility
improvement for the most impaired visibility days, and ensure no
degradation for the least impaired visibility days. The RPGs for the
first planning period are goals for the year 2018.
    Wyoming relied on WRAP modeling to establish its RPGs for 2018. The
primary tool WRAP relied upon for modeling regional haze improvements
by 2018, and for estimating Wyoming's RPGs, was the CMAQ model. The
CMAQ model was used to estimate 2018 visibility conditions in Wyoming
and all western Class I areas, based on application of anticipated
regional haze strategies in the various states' regional haze plans,
including assumed controls on BART sources.
    The Regional Modeling Center (RMC) at the University of California
Riverside conducted the CMAQ modeling under the oversight of the WRAP
Modeling Forum. The RMC developed air quality modeling inputs including
annual meteorology and emissions inventories for: (1) A 2002 actual
emissions base case; (2) a planning case to represent the 2000-2004
regional haze baseline period using averages for key emissions
categories; and (3) a 2018 base case of projected emissions determined
using factors known at the end of 2005. All emission inventories were
spatially and temporally allocated using the Sparse Matrix Operator
Kernel Emissions (SMOKE) modeling system. Each of these inventories
underwent a number of revisions throughout the development process to
arrive at the final versions used in CMAQ modeling.
    The photochemical modeling of regional haze for the WRAP states for
2002 and 2018 was conducted on the 36-km resolution national regional
planning organization domain that covered the continental United
States, portions of Canada and Mexico, and portions of the Atlantic and
Pacific Oceans along the east and west coasts. The RMC examined the
model performance of the regional modeling for the areas of interest
before determining whether the CMAQ model results were suitable for use
in the regional haze assessment of the LTS and for use in the modeling
assessment. The 2002 modeling efforts were used to evaluate air
quality/visibility modeling for a historical episode, in this case, for
calendar year 2002, to demonstrate the suitability of the modeling
systems for subsequent planning, sensitivity, and emissions control
strategy modeling. Model performance evaluation compares output from
model simulations with ambient air quality data for the same time
period to determine whether model performance is sufficiently accurate
to justify using the model to simulate future conditions. Once the RMC
determined that model performance was acceptable, it used the model to
determine the 2018 RPGs using the current and future year air quality
modeling predictions, and compared the RPGs to the uniform rate of
progress. A more detailed description of the CMAQ modeling performed
for the WRAP can be found in the Chapter 5 of the State's TSD.
    The State determined that the WRAP 2018 projections represent
significant visibility improvement and reasonable progress toward
natural visibility based upon the State's consideration of the factors
required for BART and reasonable progress. The State adopted the WRAPs
2018 projections as their RPG for each Class I area. Table 20 shows the
URP and the 2018 RPGs adopted by the State.

                                                        Table 20--Wyoming's URP and RPGs for 2018
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                20% Worst Days                                   20% Best Days
                                                         -----------------------------------------------------------------------------------------------
                                                                                Reduction
                  Wyoming Class I Areas                      2000-2004                       Needed to       2018 CMAQ       2000-2004       2018 CMAQ
                                                             Baseline        2018 URP     Reach URP Goal     Modeling        Baseline        Modeling
                                                            (deciview)      (deciview)        (Delta       Projection--     (deciview)      Projection
                                                                                deciview)      State's RPG                     (deciview)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Yellowstone National Park, Grand Teton National, Park               11.8            10.5             0.7            11.2             2.6             2.4
 Teton Wilderness.......................................
North Absaroka Wilderness, Washakie Wilderness..........            11.5            10.4             0.6            11.0             2.0             2.0
Bridger Wilderness, Fitzpatrick Wilderness..............            11.1            10.0             0.6            10.6             2.1             2.0
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 20 shows that the State's regional haze SIP is providing for
improvement in visibility for the most-impaired days for the period
ending in 2018 and allows for no degradation in visibility for the
least-impaired days.
    Table 20 also shows that Wyoming is not meeting the URP to meet
natural visibility conditions by 2064. In this case, 40 CFR
51.308(d)(1)(ii) requires the State to demonstrate, based on the four
factors in 51.308(d)(1)(i)(A), that the RPGs established in this SIP
are reasonable for this planning period and that achieving the URP in
this planning period is not reasonable. In its demonstration, the State
cited many reasons why meeting the URP was not reasonable, including
the following. First, emissions from natural sources greatly affect the
State's ability to meet the 2018 URP. As discussed earlier, WEP data
shows that emissions of OC, EC, PM2.5, and PM10
come mainly from natural or non-anthropogenic sources, such as natural
wildfire and windblown dust. The State has little or no control over
OC, EC, PM2.5, and PM10 emissions associated with
natural fire and windblown dust. Second, emissions from sources outside
the WRAP modeling domain also affect the State's ability to meet the
2018 URP. Sources outside of the modeling domain are the single largest
source region contributor to sulfate and nitrate at the State's Class I
areas. These sources are not under the control of Wyoming or the
surrounding states.
    Since the State is not meeting the URP, the State is required by 40
CFR 51.308(d)(1)(ii) to assess the number of years it would take to
reach natural conditions if visibility improvement continues at the
current rate of progress. The State has calculated the year and the
length of time to reach natural visibility as follows: Yellowstone
National Park, Grand Teton National Park, and Teton Wilderness: 2130
(126 years); North Absaroka Wilderness and Washakie Wilderness: 2136
(132 years); and Bridger Wilderness and Fitzpatrick Wilderness: 2165
(161 years).
    EPA disagrees with the State's assessment that, based on the
factors in 40 CFR 51.308(d)(1)(i)(a), all reasonable controls were
implemented by the State for this first planning period of the regional
haze program. In particular, as discussed in section VII.B.i below, we
find unreasonable the State's determination to not impose controls at
PacifiCorp Dave Johnston Units 1 and 2. As a result, EPA is proposing
to disapprove the State's RPGs, and because we are proposing to
disapprove Wyoming's RPGs, we are also proposing a FIP to replace them.
See discussion in section VII.C below.

E. Long Term Strategy

1. Emission Inventories
    Section 51.308(d)(3)(iii) requires that Wyoming document the
technical basis, including modeling, monitoring, and emissions
information, on which it relied to determine its apportionment of
emission reduction obligations necessary for achieving reasonable
progress in each mandatory Class I Federal area it affects. Wyoming
must identify the baseline emissions inventory on which its strategies
are based. 40 CFR 51.308(d)(3)(iv) requires that Wyoming identify all
anthropogenic sources of visibility impairment it considered in
developing its LTS strategy. This includes major and minor stationary
sources, mobile sources, and area sources.
    In order to meet these requirements, Wyoming relied on the emission
inventory developed by the WRAP. The State has provided an emission
inventory for SO2, NOX, VOC, OC, EC,
PM2.5, PM10, and NH3. The inventory
provides the baseline year 2002 emissions and provides projections of
future emissions in 2018 based on expected controls, growth, and other
factors. The following are the inventory source categories identified
by the State: Point, area, on-road mobile, off-road mobile,
anthropogenic fire, natural fire, road dust, fugitive dust, area source
oil and gas, and biogenic emissions. The emission inventories developed
by the WRAP were calculated using best available data and approved EPA
methods.\31\ Following is a summary of the emission inventory for each
pollutant by source.
---------------------------------------------------------------------------

    \31\ The methods WRAP used to develop these emission inventories
are described in more detail in Technical Support Document for
Technical Products Prepared by the Western Regional Air Partnership
(WRAP) in Support of Western Regional Haze Plans in the Supporting
and Related Materials section of the docket.
---------------------------------------------------------------------------

SO2
    Sulfur dioxide emissions come primarily from coal combustion at
EGUs, but smaller amounts come from natural gas combustion, mobile
sources and wood combustion.

             Table 21--Wyoming SO2 Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................      119,717       96,809          -19
Area.............................       16,689       23,093           38

On-Road Mobile...................          959           81          -92
Off-Road Mobile..................        5,866           65          -99
Oil & Gas........................          150            3          -98
Road Dust........................            0            0            0
Fugitive Dust....................            0            0            0
Windblown Dust...................            0            0            0
Anthropogenic Fire...............          173          109          -37
Natural Fire.....................        2,286        2,286            0
Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................      145,840      122,446          -16
------------------------------------------------------------------------

    The State expects a 16% reduction in SO2 emissions by
2018 due to planned controls on existing sources, even with expected
growth in generating capacity for the State.
NOX
    NOX emissions in Wyoming come mostly from point sources
and from on-road and off-road mobile sources.

             Table 22--Wyoming NOX Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................      117,806      110,109           -7
Area.............................       15,192       19,663           29
On-Road Mobile...................       38,535        9,728          -75
Off-Road Mobile..................       76,637       49,677          -35
Oil & Gas........................       14,725       34,142          132
Road Dust........................            0            0            0
Fugitive Dust....................            0            0            0
Windblown Dust...................            0            0            0
Anthropogenic Fire...............          782          484          -38
Natural Fire.....................        8,372        8,372            0
Biogenic.........................       15,925       15,925            0
                                  --------------------------------------
    Total........................      287,974      248,100          -14
------------------------------------------------------------------------

    The State expects NOX emissions to decrease by 14% by
2018, primarily due to significant reductions in mobile source
emissions. The State projects that off-road and on-road vehicles
emissions will decline by more than 55,760 tpy from the baseline 2002
emissions of 115,172 tpy.
OC
    A wide variety of sources contribute emissions to this pollutant,
including diesel emissions and combustion byproducts from wood and
agricultural burning.

              Table 23--Wyoming OC Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................          646          990           53
Area.............................        2,000        1,975           -1
On-Road Mobile...................          304          249          -18
Off-Road Mobile..................          625          411          -34
Oil & Gas........................            0            0            0
Road Dust........................           20           26           30
Fugitive Dust....................           96          133           39
Windblown Dust...................            0            0            0
Anthropogenic Fire...............        1,709          886          -48
Natural Fire.....................       23,793       23,793            0
Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................       29,193       28,463           -3
------------------------------------------------------------------------

    OC emissions from all sources are expected to show a 3% decline.
Natural fire is the largest source contributing to OC emissions. The
State does not have the ability to predict future emissions from
natural fires and thus, the State

held this category constant in the inventory.
EC
    EC is a byproduct of incomplete combustion. EC emissions mainly
come from mobile sources and natural fires.

              Table 24--Wyoming EC Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................          104          180           73
Area.............................          304          335           10
On-Road Mobile...................          443           86          -81
Off-Road Mobile..................        1,986        1,161          -42
Oil & Gas........................            0            0            0
Road Dust........................            2            2            0
Fugitive Dust....................            7            9           29
Windblown Dust...................            0            0            0
Anthropogenic Fire...............          298          153          -49
Natural Fire.....................        4,922        4,922            0
Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................        8,066        6,848          -15
------------------------------------------------------------------------

    The State predicts EC emissions to decrease approximately 15% by
2018. Reductions in manmade emissions of EC are largely due to mobile
sources emission reductions resulting from new federal emission
standards for mobile sources, especially for diesel engines.
PM2.5
    PM2.5 emissions come mainly from agricultural and mining
activities, windblown dust from construction areas, and emissions from
unpaved and paved roads.

            Table 25--Wyoming PM2.5 Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................       11,375       15,709           38
Area.............................        1,601        1,756           10
On-Road Mobile...................            0            0            0
Off-Road Mobile..................            0            0            0
Oil & Gas........................            0            0            0
Road Dust........................          160          206           29
Fugitive Dust....................        2,082        2,882           38
Windblown Dust...................        5,838        5,838            0
Anthropogenic Fire...............          242          129          -47
Natural Fire.....................        1,535        1,535            0
Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................       22,833       28,055           23
------------------------------------------------------------------------

    The State predicts emissions of PM2.5 to increase 23% by
2018. Emission increases are related to population growth and an
increase in vehicle miles traveled.
PM10
    PM10 emissions come from many of the same sources as
PM2.5 emissions but other activities like rock crushing and
processing, material transfer, open pit mining and unpaved road
emissions can be prominent sources.

             Table 26--Wyoming PM10 Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................       24,751       30,619           24
Area.............................          409          653           60
On-Road Mobile...................          171          165           -4
Off-Road Mobile..................            0            0            0
Oil & Gas........................            0            0            0
Road Dust........................        1,125        1,449           29
Fugitive Dust....................       18,030       25,144           39
Windblown Dust...................       52,546       52,546            0
Anthro Fire......................          259          109          -58
Natural Fire.....................        5,369        5,369            0

Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................      102,660      116,054           13
------------------------------------------------------------------------

    Overall, PM10 emissions are expected to increase by 13%.
Increases in coarse PM emissions are linked to population growth and
vehicle miles traveled.
NH3
    NH3 emissions come from a variety of sources including
wastewater treatment facilities, livestock operations, fertilizer
application, mobile sources, and point sources.

             Table 27--Wyoming NH3 Emissions--2002 and 2018
------------------------------------------------------------------------
                                     Baseline                  Percent
         Source Category               2002     Future 2018     Change
------------------------------------------------------------------------
Point............................          685        1,398          104
Area.............................       29,776       29,901            0
On-Road Mobile...................          538          724           35
Off-Road Mobile..................           41           57           39
Oil & Gas........................            0            0            0
Road Dust........................            0            0            0
Fugitive Dust....................            0            0            0
Windblown Dust...................            0            0            0
Anthropogenic Fire...............          218          119          -45
Natural Fire.....................        1,775        1,775            0
Biogenic.........................            0            0            0
                                  --------------------------------------
    Total........................       33,033       33,974            3
------------------------------------------------------------------------

    NH3 emissions are expected to increase by 3% by 2018.
Increases in NH3 emissions are linked to population growth
and increased vehicular traffic.
2. Consultation and Emissions Reductions for Other States' Class I
Areas
    40 CFR 51.308(d)(3)(i) requires that Wyoming consult with another
state if its emissions are reasonably anticipated to contribute to
visibility impairment at that state's Class I area(s), and that Wyoming
consult with other states if those other states' emissions are
reasonably anticipated to contribute to visibility impairment at its
Class I areas. The State participated in regional planning,
coordination, and consultation with other states in developing emission
management strategies through the WRAP. Through the WRAP consultation
process, Wyoming has reviewed and analyzed contributions from other
states that reasonably may cause or contribute to visibility impairment
in Wyoming's Class I areas and analyzed Wyoming's impact on other
states' Class I areas.
    40 CFR 51.308(d)(3)(ii) requires that if Wyoming emissions cause or
contribute to impairment in another state's Class I area, Wyoming must
demonstrate that it has included in its regional haze SIP all measures
necessary to obtain its share of the emission reductions needed to meet
the RPG for that Class I area. Section 51.308(d)(3)(ii) also requires
that, since Wyoming participated in a regional planning process, it
must ensure it has included all measures needed to achieve its
apportionment of emission reduction obligations agreed upon through
that process. As we state in the RHR, Wyoming's commitments to
participate in WRAP bind it to secure emission reductions agreed to as
a result of that process.
    The State determined it did potentially impact Class I areas in
South Dakota, Colorado, Utah, Idaho, Montana, and North Dakota (see
Table <IP_ADDRESS>-1 in the SIP). Wyoming accepted and incorporated the
WRAP-developed visibility modeling into its regional haze SIP and the
SIP includes the controls assumed in the modeling. Wyoming has
satisfied the RHR requirements for consultation and included controls
in the SIP sufficient to address the relevant requirements related to
impacts on Class I areas in other states.
    We are proposing to find that the State has met the requirements
for consultation under 40 CFR 51.308(d)(3)(i) and 40 CFR
51.308(d)(3)(ii).
3. Mandatory Long-Term Strategy Requirements
    40 CFR 51.308(d)(3)(v) requires that Wyoming, at a minimum,
consider certain factors in developing its LTS. These are: (a) Emission
reductions due to ongoing air pollution control programs, including
measures to address RAVI; (b) measures to mitigate the impacts of
construction activities; (c) emissions limitations and schedules for
compliance to achieve the reasonable progress goals; (d) source
retirement and replacement schedules; (e) smoke management techniques
for agricultural and forestry management purposes including plans that
currently exist within the state for these purposes; (f) enforceability
of emissions limitations and control measures; and (g) the anticipated
net effect on visibility due to projected changes in point, area, and
mobile source emissions over the period addressed by the LTS.
a. Reductions Due to Ongoing Air Pollution Programs
    In addition to its BART and reasonable progress determinations, the
State's LTS contains other reductions due to ongoing air pollution
programs. The State's LTS contains numerous ongoing air pollution
programs, including: (1) New Source Review Program, which is a permit
program for

the construction of new sources and the modification of existing
sources; (2) Prevention of Significant Deterioration Program, which
protects visibility impairment from proposed major stationary sources
or major modifications to existing facilities; and (3) New Source
Performance Standards, which the State incorporates by reference on an
annual basis. For a complete listing of ongoing air pollution programs
in Wyoming, see Chapter 8.2.1 of the SIP.
b. Measures To Mitigate the Impacts of Construction Activities
    Chapter 3 of the Wyoming Air Quality Standards and Regulations
(WAQSR) establishes limits on the quantity or concentration of
emissions of air pollutants from numerous sources, including
construction activities. Specifically, WAQSR Chapter 3, Section 2(f),
prescribes measures to ensure the control of fugitive dust emissions
during construction or demolition activities. WAQSR Chapter 3, Section
2(f) requires any person engaged in clearing or leveling of land,
earthmoving, excavation, or movement of trucks or construction
equipment over access haul roads or cleared land to take steps to
minimize fugitive dust from such activities. Such control measures may
include frequent watering and/or chemical stabilization. EPA approved
WAQSR Chapter 3 into the SIP on July 28, 2004 (69 FR 44965).
c. Smoke Management
    WAQSR Chapter 10 establishes restrictions and requirements on
different types of burning in Wyoming. WAQSR Chapter 10, Section 2
regulates open burning, including refuse burning, open burning of trade
wastes, open burning at salvage operations, open burning for
firefighting training, and small vegetative material open burning (not
exceeding 0.25 tons per day of PM). WAQSR Chapter 10, Section 3
regulates emissions from wood waste burners. EPA approved WAQSR Chapter
10, Section 2 and 3 into the SIP on July 28, 2004 (69 FR 44965). WAQSR
Chapter 10, Section 4 was adopted by the State and submitted to EPA to
meet the requirements for programs related to fire under 40 CFR
51.309(d)(6). Chapter 10, Section 4 seeks to minimize the impacts from
private and prescribed burning on visibility in Class I areas and
potentially affected populations. EPA is proposing approval of Chapter
10, Section 4 in a separate action.
d. Emission Limitations and Schedules for Compliance
    Chapter 6.5 of the State's SIP contains the emission limitations
and schedules for compliance for BART sources. Chapter 6.5 of the SIP
requires the BART sources to install and demonstrate compliance with
the State's BART determination as expeditiously as practicable but no
later than five years after EPA approval of the SIP. For some sources
where controls have already been installed, the State specifies an
earlier compliance deadline in Chapter 6.5 of the SIP. In addition,
Chapter 8.3.3 of the SIP contains the emission limits and compliance
schedule for LTS controls on Jim Bridger Units 1-4.
e. Source Retirement and Replacement Schedules
    The State is not currently aware of any specific scheduled
shutdowns, retirements in upcoming years, or replacement schedules,
such as planned installation of new control equipment to meet other
regulations. If such actions occur, the State will factor them into
upcoming reviews.
f. Enforceability of Wyoming's Measures
    As discussed in section VII.D of this notice, EPA is proposing to
disapprove the State's SIP because it contains inadequate monitoring,
recordkeeping, and reporting requirements, and we are proposing a FIP
to address the enforceability of BART and reasonable progress controls.
g. Anticipated Net Effect on Visibility Due to Projected Changes
    The anticipated net effect on visibility due to projected changes
in point, area, and mobile source emissions during this planning period
is addressed in section VI.D.3 of this notice.
4. Our Conclusions on Wyoming's Long-Term Strategy
    We propose to partially approve and partially disapprove Wyoming's
LTS. Because we are proposing to disapprove the NOX BART
determinations for PacifiCorp Dave Johnston Unit 3, PacifiCorp Jim
Bridger Units 1 and 2, PacifiCorp Wyodak Unit 1, and Basin Electric
Laramie River Units 1, 2, and 3, we are also proposing to disapprove
the corresponding emission limits and compliance schedules that Wyoming
relied on as part of its LTS. Because we are proposing to disapprove
the reasonable progress determination for PacifiCorp Dave Johnston
Units 1 and 2, we are also proposing to disapprove the LTS because it
does not include appropriate NOX reasonable progress
emission limits and compliance schedules for Dave Johnston Units 1 and
2. We are also proposing to disapprove the State's LTS because it does
not contain the necessary monitoring, recordkeeping, and reporting
requirements to make the BART and reasonable progress limits
practically enforceable. Except for these elements, the State's LTS
satisfies the requirements of 40 CFR 51.308(d)(3), and we are proposing
to approve it.

F. Coordination of RAVI and Regional Haze Rule Requirements

    Per 40 CFR 51.306(c), the State must provide for review and
revision of a coordinated LTS for addressing RAVI and regional haze,
and the State must submit the first such coordinated LTS with its first
regional haze SIP. The State failed to provide for the coordination of
their RAVI and regional haze LTS. We are proposing to disapprove the
State's SIP as not meeting the requirements of 40 CFR 51.306(c). We are
proposing a FIP as explained in section VII.F of this notice to meet
the coordination requirements of 40 CFR 51.306(c).

G. Monitoring Strategy and Other Implementation Plan Requirements

    40 CFR 51.308(d)(4) requires that the SIP contain a monitoring
strategy for measuring, characterizing, and reporting regional haze
visibility impairment that is representative of all mandatory Class I
Federal areas within the state. This monitoring strategy must be
coordinated with the monitoring strategy required in 40 CFR 51.305 for
RAVI. As 40 CFR 51.308(d)(4) notes, compliance with this requirement
may be met through participation in the IMPROVE network. 40 CFR
51.308(d)(4)(i) further requires the establishment of any additional
monitoring sites or equipment needed to assess whether the RPGs for all
mandatory Class I Federal areas within the state are being achieved.
    Consistent with EPA's monitoring regulations for RAVI and regional
haze, Wyoming states in Chapter 9 of the regional haze SIP that it will
rely on the IMPROVE network for compliance purposes, in addition to any
additional visibility impairment monitoring that may be needed in the
future.
    Section 51.308(d)(4)(ii) requires that states establish procedures
by which monitoring data and other information are used in determining
the contribution of emissions from within Wyoming to regional haze
visibility impairment at mandatory Class I Federal areas both within
and outside the state. The IMPROVE monitoring program is national in
scope, and other states have similar monitoring and data reporting

procedures, ensuring a consistent and robust monitoring data collection
system. As 40 CFR 51.308(d)(4) indicates, Wyoming's participation in
the IMPROVE program constitutes compliance with this requirement.
    40 CFR 51.308(d)(4)(iv) requires that the SIP provide for the
reporting of all visibility monitoring data to the Administrator, at
least annually, for each mandatory Class I Federal area in the state.
To the extent possible, Wyoming should report visibility monitoring
data electronically. 40 CFR 51.308(d)(4)(vi) also requires that the SIP
provide for other elements, including reporting, recordkeeping, and
other measures, necessary to assess and report on visibility. We
propose that Wyoming's participation in the IMPROVE network ensures
that the monitoring data is reported at least annually and is easily
accessible; therefore, such participation complies with this
requirement. IMPROVE data are centrally compiled and made available to
EPA, states and the public via various electronic formats and Web sites
including IMPROVE (http://vista.cira.colostate.edu/improve/) and VIEWS
(http://vista.cira.colostate.edu/views/).
    40 CFR 51.308(d)(4)(v) requires that Wyoming maintain a statewide
inventory of emissions of pollutants that are reasonably anticipated to
cause or contribute to visibility impairment in any mandatory Class I
Federal area. The inventory must include emissions for a baseline year,
emissions for the most recent year for which data are available, and
estimates of future projected emissions. The State must also include a
commitment to update the inventory periodically. The State's emission
inventory is discussed in section VI.F.1 of this notice. Wyoming states
in Chapter 9 of the SIP that it intends to update the Wyoming statewide
emissions inventories periodically and review periodic emissions
information from other states and future emissions projections. We
propose that this satisfies the requirement.
    40 CFR 51.308(d)(4)(vi) requires that states provide for any
additional reporting, recordkeeping, and measures necessary to evaluate
and report on visibility. The State of Wyoming, in accordance with
provisions of 40 CFR 51.308(d)(4)(vi), will track data related to
regional haze for sources for which the State has regulatory authority,
and will depend on the IMPROVE program and RPO sponsored collection and
analysis efforts for monitoring and emissions inventory data,
respectively. To ensure the availability of data and analyses to report
on visibility conditions and progress toward Class I area visibility
goals, the State of Wyoming will collaborate with members of a RPO to
ensure the continued operation of the IMPROVE program and RPO sponsored
technical support analysis tools and systems.
    We propose to find that the State's SIP satisfies the requirements
of 40 CFR 51.308(d)(4).

H. Consultation With FLMs

    Although the FLMs are very active in participating in the RPOs, the
RHR grants the FLMs a special role in the review of the regional haze
SIPs, summarized in section V.H, above. Under 40 CFR 51.308(i)(2),
states are obligated to provide the FLMs with an opportunity for
consultation, in person, and at least 60 days prior to holding a public
hearing on the regional haze SIP. The State provided an opportunity for
FLM consultation, in person and at least 60 days prior to holding any
public hearing on the SIP. As required by 40 CFR Section 51.308(i)(3),
the State has included FLM comments and State responses in Chapter 11
of the Wyoming TSD.
    40 CFR 51.308(i)(3) requires that States provide in its regional
haze SIP a description of how it addressed any comments provided by the
FLMs. The FLMs formally commented on the Wyoming proposed SIP in
November and December of 2010. The FLM comments provided support for
the modeling approach used by the State in the BART determinations and
complimented the State on thorough BART, reasonable progress, and area
source analysis. The FLMs also recommended the State reevaluate costs
and emission limits for some of the BART and reasonable progress
sources. Chapter 11 of the State's TSD provides detailed information on
the State's response to FLM comments.
    Lastly, 40 CFR 51.308(i)(4) specifies the regional haze SIP must
provide procedures for continuing consultation between a State and FLMs
on the implementation of the visibility protection program required by
40 CFR 51.308. This includes development and review of implementation
plan revisions and five-year progress reports and the implementation of
other programs having the potential to contribute to impairment of
visibility in mandatory Class I Federal areas. Pursuant to Chapter 11.2
of the SIP, the State will provide the FLMs an opportunity to review
and comment on SIP revisions, the five-year progress reports, and other
developing programs that may contribute to Class I visibility
impairment.
    We are proposing that the State's SIP satisfies the requirements of
40 CFR 51.308(i).

I. Periodic SIP Revisions and 5-Year Progress Reports

    40 CFR 51.308(f) requires a State to revise and submit its regional
haze SIP to EPA by July 31, 2018, and every ten years thereafter.
Pursuant to Chapter 10 of the SIP, the State will provide this
revision. In accordance with the requirements listed in 40 CFR
51.308(g), the State will submit a report on reasonable progress to EPA
every five years following the initial submittal of the SIP. That
report will be in the form of an implementation plan revision. The
State's report will evaluate the progress made toward the RPGs for each
mandatory Class I area located within the State and in each mandatory
Class I area located outside the State, which have been identified as
being affected by emissions from the State. The State will also
evaluate the monitoring strategy adequacy in assessing RPGs.
    Based on the findings of the five-year progress report, 40 CFR
51.308(h) requires a State to make a determination of adequacy of the
current implementation plan. The State must take one or more of the
actions listed in 40 CFR 51.308(h)(1) through (4) that are applicable
at the same time as the State submits a five-year progress report.
Chapter 12 of the SIP requires the State to make an adequacy
determination of the current SIP pursuant to 40 CFR 51.308(h)(1)
through (4) at the same time a five-year progress report is due.
    We propose to find the State's SIP satisfies the requirements of 40
CFR 51.308(f)-(h).

VII. Federal Implementation Plan

    EPA is proposing a FIP to address the deficiencies indentified in
our proposed partial disapproval of Wyoming's regional haze SIP. In
lieu of this proposed FIP, or a portion thereof, we would propose
approval of a SIP revision if the State submits such a revision and the
revision matches the terms of our proposed FIP. We encourage the State
to submit a SIP revision to replace the FIP, either before or after our
final action.

A. Disapproval of the State's NOX BART Determinations and
Federal Implementation Plan for NOX BART Determinations and
Limits

    As noted above, the State provided five-factor analyses that
considered all factors, except analyzing the degree of visibility
improvement modeling for each individual pollutant. Thus, in
disapproving specific State BART

determinations, we are basing our analysis on information provided by
the State in their BART analysis, with the exception of visibility
improvement modeling. We have accepted the cost information provided by
the State. As discussed above, visibility improvement modeling was
performed by the EPA. EPA is proposing to disapprove the State's
NOX BART determinations, and we are proposing to issue a
BART FIP, for the following units: PacifiCorp Dave Johnston Unit 3,
PacifiCorp Jim Bridger Units 1 and 2, PacifiCorp Wyodak Unit 1, and
Basin Electric Laramie River Units 1, 2, and 3. EPA's rationale for
disapproving the State's BART determinations for these units, as well
as EPA's BART FIP determinations and emission limits, is discussed
below.
1. Disapproval of the State's Basin Electric Laramie River Units 1-3
NOX BART Determination and FIP To Address NOX
BART
Wyoming's NOX BART Determination
    All three units are currently controlled with LNBs with a permit
limit of 0.5 lbs/MMBtu (3-hour rolling average). The State determined
that new LNBs, OFA, LNBs and OFA, SNCR/SCR hybrid, LNBs and OFA with
SNCR, and SCR were technically feasible for reducing NOX
emissions at Units 1-3. The State determined that natural gas reburn
was technically infeasible. The State did not identify any energy or
non-air quality environmental impacts that would preclude the selection
of any of the controls evaluated, and there are no remaining-useful-
life issues for this source. A summary of the State's NOX
BART analysis is provided in Tables 28-30 below. As discussed above,
the visibility improvement modeling results in these tables were
developed by EPA. Baseline NOX emissions are 6,320 tpy for
Unit 1, 6,285 tpy for Unit 2, and 6,448 tpy for Unit 3 based on an
average on 2001-2003 actual emissions.

                                       Table 28--Summary of Basin Electric Laramie River Unit 1 NOX BART Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta dv for
                                                                           Emission Rate     Emission                      Average Cost     the Maximum
                   Control Technology                         Control     (lb/MMBtu) (30-    Reduction      Annualized     Effectiveness       98th
                                                          Efficiency (%)    day Rolling        (tpy)           Costs          ($/ton)       Percentile
                                                                             Average)                                                     Impact at Wind
                                                                                Cave National
                                                                                Park)
--------------------------------------------------------------------------------------------------------------------------------------------------------
OFA.....................................................            14.8            0.23             936        $625,000            $668            0.08
LNBs....................................................            14.8            0.23             936       1,360,000           1,453            0.08
LNBs with OFA...........................................            14.8            0.23             936       1,944,000           2,077            0.08
SNCR/SCR Hybrid.........................................            25.9            0.20           1,639       7,429,000           4,534  ..............
LNBs with OFA and SNCR..................................            55.6            0.12           3,511       7,365,000           2,098            0.32
SCR.....................................................            74.1            0.07           4,681      15,787,000           3,372            0.44
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the controls evaluated is as
follows: LNBs with OFA and SNCR: $2,105/ton, and SCR: $7,198/ton.

                                       Table 29--Summary of Basin Electric Laramie River Unit 2 NOX BART Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta dv for
                                                                           Emission Rate     Emission                      Average Cost     the Maximum
                   Control Technology                         Control     (lb/MMBtu) (30-    Reduction      Annualized     Effectiveness       98th
                                                          Efficiency (%)    day Rolling        (tpy)           Costs          ($/ton)       Percentile
                                                                             Average)                                                     Impact at Wind
                                                                                Cave National
                                                                                Park)
--------------------------------------------------------------------------------------------------------------------------------------------------------
OFA.....................................................            14.3            0.23             931        $625,000            $671            0.08
LNBs....................................................            14.3            0.23             931       1,360,000           1,461            0.08
LNBs with OFA...........................................            14.3            0.23             931       1,944,000           2,088            0.08
SNCR/SCR Hybrid.........................................            25.5            0.20           1,630       7,429,000           4,559  ..............
LNBs with OFA and SNCR..................................            55.3            0.12           3,492       7,365,000           2,109            0.32
SCR.....................................................            73.9            0.07           4,656      15,787,000           3,391            0.44
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the controls evaluated is as
follows: LNBs with OFA and SNCR: $2,117/ton; and SCR: $7,242/ton.

                                       Table 30--Summary of Basin Electric Laramie River Unit 3 NOX BART Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta dv for
                                                                           Emission Rate     Emission                      Average Cost     the Maximum
                   Control Technology                         Control     (lb/MMBtu) (30-    Reduction      Annualized     Effectiveness       98th
                                                          Efficiency (%)    day Rolling        (tpy)           Costs          ($/ton)       Percentile
                                                                             Average)                                                     Impact at Wind
                                                                                Cave National
                                                                                Park)
--------------------------------------------------------------------------------------------------------------------------------------------------------
OFA.....................................................            16.5            0.23             955        $625,000            $654            0.08

LNBs....................................................            16.5            0.23             955       1,360,000           1,424            0.08
LNBs with OFA...........................................            16.5            0.23             955       1,944,000           2,036            0.08
SNCR/SCR Hybrid.........................................            27.4            0.20           1,672       7,429,000           4,444  ..............
LNBs with OFA and SNCR..................................            56.4            0.12           3,582       7,365,000           2,056            0.33
SCR.....................................................            74.6            0.07           4,777      15,787,000           3,305            0.44
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the controls evaluated is as
follows: LNBs with OFA and SNCR: $2,064/ton, and SCR: $7,054/ton.
    The State eliminated the SNCR/SCR hybrid from further consideration
because it has higher cost effectiveness and lower control efficiency
compared to new LNBs plus OFA with SNCR.
    Based on its consideration of the five factors, the State
determined LNBs with OFA was reasonable for NOX BART. The
State determined that the NOX BART emission limits for
Laramie River Unit 1 are 0.23 lb/MMBtu (30-day rolling average), 1,348
lb/hr (30-day rolling average), and 5,343 tpy. The State determined the
NOX BART emission limits for Laramie River Unit 2 are 0.23
lb/MMBtu (30-day rolling average), 1,348 lb/hr (30-day rolling
average), and 5,343 tpy. The State determined the NOX BART
emission limits for Laramie River Unit 3 are 0.23 lb/MMBtu (30-day
rolling average), 1,386 lb/hr (30-day rolling average), and 5,493 tpy.
    The State's proposed SIP required additional NOX
emission reductions for Laramie River under its LTS. Based on the costs
and visibility improvement for Laramie River Station Units 1, 2, and 3,
the State proposed installation of two SCRs, or equivalent performing
emission control systems, at any of the three units. The State proposed
that the add-on NOX control achieve an emission rate, on an
individual unit basis, at or below 0.07 lb/MMBtu on a 30-day rolling
average. The State proposed that the add-on controls be installed and
operational on one of the Laramie River Station units by December 31,
2018 and on a second Laramie River Station unit by December 31, 2023.
    On March 8, 2010, Basin Electric Power Cooperative appealed the
additional controls proposed by the State under its LTS before the
Wyoming Environmental Quality Council. The State entered into a
settlement agreement on November 16, 2010 with Basin Electric Power
Cooperative (a copy of the settlement agreement is included in the
State's revised NOX BART Analysis for Laramie River dated
January 3, 2011). As part of the settlement agreement, the State agreed
to remove the requirement for Basin Electric to install additional
controls under the LTS. In return, Basin Electric agreed to additional
NOX emissions reductions under BART. Under the settlement
agreement, Basin Electric agreed to a NOX emission limit of
0.21 lb/MMBtu (30-day rolling average) on all three units. Basin
Electric also agreed to a NOX emission limit for Unit 1 and
Unit 2 of 4,780 tpy and a NOX emission limit for Unit 3 of
4,914 tpy, effectively capping emissions from all three units at 12,773
tpy. In the SIP adopted by the State, the State determined the emission
limits in the settlement agreement were BART for Basin Electric Laramie
River Units 1, 2, and 3.
EPA's Conclusions on Basin Electric Laramie River Units 1-3
NOX BART Determination and FIP for NOX BART
    EPA does not agree with the State's conclusion that a limit of 0.21
lb/MMBtu is reasonable for BART for Laramie River Units 1, 2, and 3,
which can be achieved with the installation and operation of LNBs with
OFA. In particular, the cost effectiveness values for LNBs with OFA
plus SNCR at this unit is only slightly higher than LNBs with OFA
(i.e., about $20/ton), with incremental costs of approximately
$2,100.\32\ The increase in cost effectiveness for LNBs with OFA plus
SNCR affords a visibility improvement of 0.23 delta deciview per unit
over LNBs plus OFA. LNBs with OFA plus SNCR would result in total
NOX emissions of 8,468 tpy--4,305 tpy less than the State's
BART determination. We find that it was unreasonable for the State not
to determine that LNBs with OFA plus SNCR was NOX BART for
Laramie River Units 1-3. Thus, we are proposing to disapprove the
State's NOX BART determination for Basin Electric Laramie
River Units 1, 2, and 3 and proposing a FIP for NOX BART as
explained below.
---------------------------------------------------------------------------

    \32\ Since the State did not provide costs for the source to
achieve a 0.21 lb/MMBtu emission limit and EPA did not model a 0.21
lb/MMBtu control option, we are basing our analysis on the
information for LNBs with OFA at a limit of 0.23 lb/MMBtu.
---------------------------------------------------------------------------

    Based on our examination of the State's costs estimates, emission
reductions, and the predicted visibility improvement, we propose to
find that LNBs with OFA plus SNCR at an emission limit of 0.12 lb/MMBtu
(30-day rolling average) is reasonable for NOX BART for
Basin Electric Laramie River Units 1, 2, and 3. We are proposing that
the FIP NOX BART emission limit for Basin Electric Laramie
River Unit 1, Unit 2, and Unit 3 is 0.12 lb/MMBtu (30-day rolling
average).
    We have eliminated the single highest performing option from
consideration--LNBs with OFA plus SCR--because the cost effectiveness
value is significantly higher than LNBs with OFA and there is a
comparatively small incremental visibility improvement over LNBs with
OFA.
    We propose that Basin Electric meet our proposed emission limit at
Laramie River Units 1, 2, and 3 no later than five years after EPA
finalizes action on our proposed FIP. This is consistent with the
requirements of 40 CFR 51.308(e)(iv).
2. Disapproval of the State's PacifiCorp Dave Johnston Unit 3
NOX BART Determination and FIP To Address NOX
BART
Wyoming's NOX BART Determination
    Dave Johnston Unit 3 is currently uncontrolled for NOX.
The State determined LNBs with advanced OFA, LNBs with advanced OFA and
SNCR, and LNBs with advanced OFA and SCR were technically feasible for
controlling

NOX emissions from Unit 3. The State did not identify any
technically infeasible controls.
    The State did not identify any energy or non-air quality
environmental impacts that would preclude the selection of any of the
controls evaluated, and there are no remaining-useful-life issues for
this source. Baseline NOX emissions are 5,814 tpy for Unit 3
based on unit heat input rate of 2,500 MMBtu/hr and 7,884 hours of
operation. A summary of the State's NOX BART analysis and
the visibility impacts is provided in Table 31 below.

                                               Table 31--Summary of Dave Johnston Unit 3 NOX BART Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta
                                                                           Emission Rate                                                   deciview for
                                                              Control     (lb/MMBtu) (30-    Emission       Annualized     Average Cost     the Maximum
                   Control Technology                       Efficiency      day Rolling      Reduction         Costs       Effectiveness       98th
                                                                (%)          Average)          (tpy)                          ($/ton)       Percentile
                                                                                Impact at Wind
                                                                                Cave National
                                                                                Park)
--------------------------------------------------------------------------------------------------------------------------------------------------------
LNB with advanced OFA...................................            46.8            0.28           2,723      $1,764,775            $648            0.77
New LNB with advanced OFA and SNCR......................            63.9            0.19           3,717       2,679,192             721            0.94
LNB with advanced OFA and SCR...........................            86.7            0.07           5,041      16,347,519           3,243            1.16
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the controls evaluated is as
follows: New LNB with advanced OFA and SNCR: $920/ton, and LNB with
advanced OFA and SCR: $10,234/ton.
    Based on its consideration of the five factors, the State
determined LNBs with OFA was reasonable for NOX BART. The
State determined the cost of compliance (capital costs and annual
operating and maintenance costs) were significantly higher for the
addition of SCR. The State determined the NOX BART emission
limits for Unit 3 are 0.28 lb/MMBtu (30-day rolling average), 784 lb/hr
(30-day rolling average), and 3,434 tpy.
EPA's Conclusions on Dave Johnston Unit 3 NOX BART
Determination and FIP for NOX BART
    EPA does not agree with the State's conclusion that a limit of 0.28
lb/MMBtu is reasonable for NOX BART for Dave Johnston Unit
3, which can be achieved with the installation and operation on LNBs
with OFA. In particular, the cost effectiveness values for LNB with OFA
and SNCR at this unit is only $73/ton higher than LNBs with OFA, with
incremental costs of $920. The increase in cost effectiveness for LNBs
with OFA plus SNCR affords visibility improvement over LNBs plus OFA of
0.17 delta deciview. LNBs with OFA plus SNCR would result in an
additional reduction of 994 tons of NOX. We find that it was
unreasonable for the State not to determine that LNBs with OFA plus
SNCR was NOX BART for Dave Johnston Unit 3. Thus, we are
proposing to disapprove the State's NOX BART determination
for Dave Johnston Unit 3 and proposing a FIP for NOX BART as
explained below.
    Based on our examination of the State's costs estimates, emission
reductions, and the predicted visibility improvement, we propose to
find that LNBs with OFA plus SNCR at an emission limit of 0.19 lb/MMBtu
(30-day rolling average) is reasonable for NOX BART for Dave
Johnston Unit 3. We are proposing that the FIP NOX BART
emission limit for PacifiCorp Dave Johnston Unit 3 is 0.19 lb/MMBtu
(30-day rolling average).
    We have eliminated the single highest performing option from
consideration--LNBs with OFA plus SCR--because the cost effectiveness
value is significantly higher than LNBs with OFA and there is a
comparatively small incremental visibility improvement over LNBs with
OFA.
    We propose that PacifiCorp meet our proposed emission limit at Dave
Johnston Unit 3 no later than five years after EPA finalizes action on
our proposed FIP. This is consistent with the requirements of 40 CFR
51.308(e)(iv).
3. Disapproval of the State's PacifiCorp Jim Bridger Units 1 and 2
NOX BART Determination and FIP To Address NOX
BART
Wyoming's NOX BART Determination
    PacifiCorp Jim Bridger Units 1 and 2 are equipped with early
generation LNBs with a permit limit of 0.70 lb/MMBtu (3-hour fixed).
The State determined that LNBs with SOFA, ROFA, LNBs with SOFA plus
SNCR, and LNBs with SOFA plus SCR were technically feasible for
controlling NOX emissions. The State did not identify any
technically infeasible options.
    The State did not identify any energy or non-air quality
environmental impacts that would preclude the selection of any of the
controls evaluated, nor are there any remaining-useful-life issues for
this source. Baseline NOX emissions are 10,643 tpy for all
both units based on unit heat input rate of 6,000 MMBtu/hr and 7,884
hours of operation. A summary of the State's NOX BART
analysis and the visibility impacts is provided in Table 32 below.\33\
---------------------------------------------------------------------------

    \33\ We are assuming the same costs for Unit 2 as the other Jim
Bridger Units. The State analyzed Unit 2 using post installation of
LNBs/OFA costs so the cost information provided in their analysis is
not consistent with an uncontrolled baseline.

                                   Table 32--Summary of Jim Bridger Units 1 and 2 NOX BART Analysis--Costs per Boiler
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta deciview
                                                               Control     Emission Rate     Emission                   Average Cost    for  the Maximum
                     Control Technology                       Efficiency  (lb/MMBtu) (30-    Reduction     Annualized   Effectiveness   98th Percentile
                                                                 (%)        day Rolling        (tpy)         Costs         ($/ton)       Impact at  Mt.
                                                                             Average)                                                        Zirkel
                                                                                Wilderness)--
                                                                                Units 1--3/4-\34\
--------------------------------------------------------------------------------------------------------------------------------------------------------
LNB with SOFA..............................................         42.2            0.26           4,493   $1,144,969            $255            .41/.47
New LNB with SOFA and SNCR.................................         55.6            0.20           5,913    2,710,801             459            .52/.62
LNB with SOFA and SCR......................................         84.4            0.07           8,987   20,296,400           2,258            .76/.82
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the control evaluated is as
follows: New LNB with SOFA and SNCR: $1,103/ton, and LNB with SOFA and
SCR: $5,721/ton.
---------------------------------------------------------------------------

    \34\ Unit 4 has different modeling results than the other three
units as the stack parameters used in the modeling are different
enough from Units 1-3 to yield different modeled results.
---------------------------------------------------------------------------

    Based on its consideration of the five factors, the State
determined LNBs with SOFA was reasonable for NOX BART. The
State determined the cost of compliance (capital costs and annual
operating and maintenance costs) were significantly higher for the
addition of SCR. The State determined the NOX BART emission
limits for Jim Bridger Units 1 and 2 are 0.28 lb/MMBtu (30-day rolling
average), 1,560 lb/hr (30-day average), and 6,833 tpy.
    PacifiCorp is required to install additional controls under the
State's LTS. The State determined that based on the cost of compliance
and visibility improvement presented by PacifiCorp in the BART
applications for Jim Bridger Units 1 and 2 and taking into
consideration the logistical challenge of managing multiple pollution
control installations within the regulatory time allotted for
installation of BART by the RHR, additional controls would be required
under the LTS but not BART. With respect to Jim Bridger Units 1 and 2,
the State has required PacifiCorp to install SCR, or other
NOX control systems, to achieve an emission limit or
otherwise reduce NOX emissions to achieve a 0.07 lb/MMBtu
30-day rolling average NOX emissions rate. PacifiCorp is
required to meet the 0.07 lb/MMBtu emission rate on Unit 1 prior to
December 31, 2021 and on Unit 2 prior to December 31, 2022.
    EPA does not agree with the State's conclusion that a limit of 0.26
lb/MMBtu is reasonable for BART for Jim Bridger Units 1 and 2, which
can be achieved with the installation and operation on LNBs with SOFA.
In particular, the cost effectiveness values for LNBs with SOFA and SCR
at each unit is $2,258 with approximately 0.80 delta deciview
visibility improvement. The cost effectiveness values are reasonable
and the visibility improvement significant for LNBs with SOFA plus SCR.
In addition, the costs are within the range that Wyoming has considered
reasonable in the BART context.\35\ LNBs with OFA plus SCR would result
in an additional reduction of 4,494 tpy of NOX emissions at
each unit. This difference is substantial. We find that it was
unreasonable for the State not to determine that LNBs with OFA plus SCR
was NOX BART for Jim Bridger Units 1 and 2. Though the State
is requiring the installation of SCR on Units 1 and 2 under its LTS,
the compliance date for both installations is beyond the five-years
allowed for BART sources by 40 CFR 51.308(e)(iv). Thus, we are
proposing to disapprove the State's NOX BART determination
for Jim Bridger Units 1 and 2 and proposing a FIP for NOX
BART as explained below.
---------------------------------------------------------------------------

    \35\ Wyoming determined that LNBs with OFA and SCR was BART for
Naughton Unit 3. The cost effectiveness of SCR for Naughton Unit 3
is $2,830 with 1.0 deciview of visibility improvement.
---------------------------------------------------------------------------

    Based on our examination of the State's costs estimates, emission
reductions, and the predicted visibility improvement, we propose to
find that LNBs with SOFA plus SCR at an emission limit of 0.07 lb/MMBtu
(30-day rolling average) is reasonable for NOX BART for Jim
Bridger Units 1 and 2. Because our examination of the factors leads us
to propose SCR is reasonable for BART, we have eliminated SNCR from
further consideration. We are proposing that the FIP NOX
BART emission limit for PacifiCorp Units 1 and 2 is 0.07 lb/MMBtu (30-
day rolling average).
    We propose that PacifiCorp meet our proposed emission limit at Jim
Bridger Unit 1 and 2 no later than five years after EPA finalizes
action on our proposed FIP. This is consistent with the requirements of
40 CFR 51.308(e)(iv).
4. Proposals in the Alternative for PacifiCorp Jim Bridger Units 1, 2,
3, and 4 NOX BART
    As noted above, EPA is seeking comment on a proposal (``first
proposed approach'') to approve in part and disapprove in part the
regional haze plan submitted by the State. Among other things, EPA's
proposal would determine that BART for Units 1 and 2 of the BART-
eligible Jim Bridger power plant is SCR, and would establish
corresponding NOx emission limits for these units that would have to be
achieved within 5 years of our final action.\36\ This would have the
effect of accelerating the installation of the SCR controls at these
units that the State and source owner (PacifiCorp) had proposed to
install later (in the 2021-2022 time-period). The State determined that
BART for these units is LNB plus OFA, and selected the 2021-2022 time-
period for SCR-based emission limits as a reasonable progress measure.
The delay was based on the large number of actions PacifiCorp is
undertaking (or helping to finance) at a large number of EGUs in
Wyoming, Utah, Colorado, and Arizona that it owns and operates or co-
owns.
---------------------------------------------------------------------------

    \36\ The proposed regulatory language for this rulemaking only
covers our first proposed approach.
---------------------------------------------------------------------------

    EPA is also seeking comment on an alternative approach (``second
proposed approach'') that differs from our first proposed approach only
with regard to Units 3 and 4 at Jim Bridger. The second proposed
approach would only differ from the first proposed approach by allowing
PacifiCorp to install SCR at Jim Bridger Units 3 and 4 within five
years from the date of our final action. This would differ from the
first proposed approach that requires PacifiCorp to install SCR at Unit
3 by 2015 and Unit 4 by 2016, while we would still propose SCR on Units
1 and 2 within the five year BART installation timeframe. This second
proposed approach would allow PacifiCorp flexibility on timing for the

installation of SCR on all four Jim Bridger Units within the BART
installation timeline allowed by the RHR. Installing SCR on all four
units within the statutory five year period would provide PacifiCorp
maximum flexibility to manage the implementation of controls on all the
units.
    EPA also is seeking comment on another alternative approach
(``third proposed approach'') that differs from the first proposed
approach only with regard to Units 1 and 2 at Jim Bridger. This third
proposed approach would include a different determination regarding
BART for these units and would have the effect of approving the state's
timeline for the installation of SCR technologies at Units 1 and 2.
    PacifiCorp asserted to the State during formulation of the SIP
proposal, and has since asserted directly to EPA, that a number of
factors, when considered together, suggest that requiring installation
of SCR at Jim Bridger Units 1 and 2 earlier than 2021-2022 is not
reasonable. First, PacifiCorp points to the large number of retrofit
actions it is taking at 20 coal-fired electric generating units in
Wyoming, Utah, and Arizona in order to reduce their emissions.\37\
These retrofits are intended to comply with the requirements in the
regional haze SIPs that these states have submitted to EPA and with
other regulatory requirements, including required controls for mercury
and acid gases under the recent Mercury and Air Toxics Standards rule.
The company claims that there are high capital costs for the measures
required for these air quality-improving retrofits. Moreover,
PacifiCorp states that accelerating the required installation of SCR at
Jim Bridger Units 1 and 2 to late 2017, rather than the 2021 and 2022
dates established by the State, would significantly increase the costs
to the utility and to its customers.\38\
---------------------------------------------------------------------------

    \37\ For a listing of PacifiCorp's retrofit actions, see Table 1
of Exhibit A--PacifiCorp's Emissions Reductions Plan in Chapter 6 of
the State's TSD.
    \38\ See Exhibit A--PacifiCorp's Emissions Reductions Plan in
Chapter 6 of the State's TSD.
---------------------------------------------------------------------------

    In addition, the company asserts that it has designed the
installation schedule in order to minimize the number of units that are
out of service system wide for installation of emissions controls at
any one time. Its goal, it asserts, is to be able to maintain service
to its customers with an adequate capacity margin. The company asserts
that accelerating the timeline for installation of SCR would upset the
orderly shut-down schedule they have devised and would threaten both
service interruptions and an increased risk of spot-purchases of more
expensive electrical energy, if it is available, to serve customers,
but that either eventuality would significantly increase costs to its
customers.\39\
---------------------------------------------------------------------------

    \39\ See Exhibit A--PacifiCorp's Emissions Reductions Plan in
Chapter 6 of the State's TSD.
---------------------------------------------------------------------------

    Taken together, PacifiCorp claims that the schedule for
installation of emissions control devices envisioned in our first
proposed approach would be excessively costly and would pose service
interruption risks for electrical energy customers over a large part of
the region. EPA notes that PacifiCorp has offered these claims taking
into account only the requirements in the SIPs that have been submitted
to EPA by Wyoming, Utah, Colorado, and Arizona. Today's proposal
includes requirements that would likely require the additional
installation of SNCRs at two units owned by PacifiCorp in Wyoming. In
addition, we have proposed to partially disapprove the SIP for Utah,
and the eventual resolution of this disapproval may involve
requirements for retrofits of more units owned by PacifiCorp in that
state. We have not yet proposed action on the SIP for Arizona, and the
possibility that the Cholla power plant that is partially owned by
PacifiCorp may require retrofits not already in PacifiCorp's plans,
cannot be ruled out at this time.
    Based on the claims made both by the State and PacifiCorp and
noting the additional requirements in the proposed FIP for Wyoming and
the possibility of additional requirements in future FIPs or SIPs in
Utah and Arizona, EPA is seeking comment on these assertions of cost
infeasibility and risk to electrical power reliability, as well as the
desirability of the third proposed approach including the possible
rationale for this third approach as described below.
    Our third proposed approach has two parts, one addressing BART and
one addressing reasonable progress with respect to Jim Bridger. First,
EPA would determine that the facts indicate that BART for the all the
units at Jim Bridger is SCR when the units are considered individually
based on the five factors without regard the status of those factors
for other units in the PacifiCorp system. However, when the five
factors are considered across all the units in that system, including
the fact that EPA's actions on the SIPs for Wyoming, Utah, and Arizona
may create additional retrofit obligations for other PacifiCorp-owned
EGUs, BART for Jim Bridger as a whole is SCR on Units 3 and 4 and LNB
plus OFA on Units 1 and 2. Costs, considered broadly, would be
unreasonable to require any further retrofits at this source within 5
years of our final action. We note that the CAA establishes 5 years at
the longest period that can be allowed for compliance with BART
emission limits.
    The second part of our third proposed approach is that EPA would
approve the SIP with regard to the State's determination that the
appropriate level of NOX control for Units 1 and 2 at Jim
Bridger for purposes of reasonable progress is the SCR-based emission
limit in the SIP, with compliance dates of December 31, 2021 for Unit 2
and December 31, 2022 for Unit 1. We believe it may be reasonable and
feasible for these retrofits to be completed somewhat earlier than
these dates even if, as would be necessary to conclude this third
approach to have merit, they cannot be completed within 5 years of our
final action. However, in the context of reasonable progress in the
second planning period of the regional haze program, we believe it may
be appropriate to give considerable deference to the State's
conclusions about what controls are reasonable and when they should be
implemented. Thus, assuming that we were to finalize this third
approach, we do not believe at this time that it would be appropriate
to disapprove the State's preferred compliance deadlines for Units 1
and 2.
    Under the third proposed approach, we would approve the SIP's
provisions for Units 1 and 2 and not adopt a FIP, because while we
would disagree with the State's reasoning, we would be agreeing with
the outcome in terms of the sequence of emission limits that apply to
these units and their compliance deadlines. We would be agreeing with
the outcome within the context of the phased regional haze statutory
and regulatory framework.
    As stated above, we are asking for comments and information
pertaining to our second and third proposed approaches. We need more
information to be able to support either alternative approach. If we
receive such information, we will provide notice to the public on the
availability of such information. We request that any information be
submitted as soon as possible, but preferably no later than 30 days
after the publication date of this notice. We are requesting that
information be submitted within this timeframe to give the public an
opportunity to review and comment on the information before the end of
the comment period.

5. Disapproval of the State's PacifiCorp Wyodak Unit 1 NOX
BART Determination and FIP To Address NOX BART
Wyoming's NOX BART Determination
    Wyodak Unit 1 is currently controlled for NOX emissions
with early generation LNBs with a permit limit of 0.70 lb/MMBtu (3-hour
block). The State determined new LNBs with OFA, existing LNBs with
ROFA, new LNBs with OFA plus SNCR, and LNBs with OFA plus SCR were
technically feasible for controlling NOX emissions. The
State did not identify any technically infeasible control options.
    The State did not identify any energy or non-air quality
environmental impacts that would preclude the selection of any of the
controls evaluated, and there are no remaining-useful-life issues for
this source. A summary of the State's NOX BART analyses for
Unit 1 is provided in Table 33 below. Baseline NOX emissions
are 5,744 tpy based on the unit heat input rate of 4,700 MMBtu/hr and
7,884 hours of operation per year.

                                                  Table 33--Summary of Wyodak Unit 1 NOX BART Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Visibility
                                                                                Improvement
                                                                                (Delta dv for
                                                              Control      Emission Rate     Emission                      Average Cost     the Maximum
                   Control Technology                       Efficiency    (lb/MMBtu) (30-    Reduction      Annualized     Effectiveness       98th
                                                                (%)         day Rolling        (tpy)           Costs          ($/ton)       Percentile
                                                                             Average)                                                     Impact at Wind
                                                                                Cave National
                                                                                Park)
--------------------------------------------------------------------------------------------------------------------------------------------------------
LNBs with OFA...........................................            25.8            0.23           1,483      $1,306,203            $881            0.25
LNBs with OFA and SNCR..................................            41.9            0.18           2,409       2,306,728             958            0.40
LNBs with OFA and SCR...................................            77.4            0.07           4,447      18,910,781           4,252            0.72
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Incremental cost effectiveness for the controls evaluated is as
follows: LNBs with OFA and SNCR: $1,080/ton, and LNBs with OFA and SCR:
$8,147/ton.
    Based on its consideration of the five factors, the State
determined LNBs with OFA was reasonable for NOX BART for
Unit 1. The State determined other control technologies were not
reasonable based on the high cost effectiveness and low visibility
improvement. The State determined the NOX BART emission
limits for Wyodak Unit 1 are 0.23 lb/MMBtu (30-day rolling average),
1,081 lb/MMBtu (30-day rolling average), and 4,735 tpy.
EPA's Conclusions on Wyodak Unit 1 NOX BART Determination
and FIP for NOX BART
    EPA does not agree with the State's conclusion that a limit of 0.23
lb/MMBtu is reasonable for NOX BART for Wyodak Unit 1, which
can be achieved with the installation and operation of LNBs with OFA.
In particular, the cost effectiveness value for LNB with OFA plus SNCR
at this unit is only $77/ton higher than LNBs with OFA, with an
incremental cost of $1,080. The increase in cost effectiveness for LNBs
with OFA plus SNCR affords a visibility improvement of 0.15 deciviews
over LNBs plus OFA. LNBs with OFA plus SNCR would result in an
additional reduction of around 900 tons of NOX. We find that
it was unreasonable for the State not to determine that LNBs with OFA
plus SNCR was NOX BART for Wyodak Unit 1. Thus, we are
proposing to disapprove the State's NOX BART determination
for Wyodak Unit 1 and proposing a FIP for NOX BART as
explained below.
    Based on our examination of the State's costs estimates, emission
reductions, and the predicted visibility improvement, we propose to
find that LNBs with OFA plus SNCR at an emission limit of 0.18 lb/MMBtu
(30-day rolling average) is reasonable for NOX BART for
Wyodak Unit 1. We are proposing that the FIP NOX BART
emission limit for PacifiCorp Wyodak Unit 1 is 0.18 lb/MMBtu (30-day
rolling average).
    We have eliminated the single highest performing option from
consideration--LNBs with OFA plus SCR--because the cost effectiveness
value is significantly higher than LNBs with OFA and there is a
comparatively small incremental visibility improvement over LNBs with
OFA.
    We propose that PacifiCorp meet our proposed emission limit at
Wyodak Unit 1 no later than five years after EPA finalizes action on
our proposed FIP. This is consistent with the requirements of 40 CFR
51.308(e)(iv).

B. Disapproval of the State's NOX Reasonable Progress Determinations
and Federal Implementation Plan for NOX Reasonable Progress
Determinations and Limits

    We are proposing to disapprove the State's reasonable progress
determination for PacifiCorp Dave Johnston Unit 1 and Unit 2, and we
are proposing a reasonable progress NOX FIP for these units,
as explained below. As noted above, the State provided four-factor
analyses that adequately evaluated the required factors. Thus, in
disapproving the State's reasonable progress determination, we are
basing our analysis on information provided by the State in its
reasonable progress analysis, with the exception of visibility
improvement modeling.
    We concluded that it is also appropriate for this facility to
consider a fifth factor for evaluating potential reasonable progress
control options--the degree of visibility improvement that may
reasonably be anticipated from the use of the reasonable progress
controls. Our reasonable progress guidance contemplates that states (or
EPA in lieu of a state) may be able to consider other relevant factors
for reasonable progress sources (see EPA's Guidance for Setting
Reasonable Progress Goals under the Regional Haze Program,
(``Reasonable Progress Guidance''), pp. 2-3, July 1, 2007). We find it
appropriate, in certain circumstances, to consider visibility
improvement when evaluating potential reasonable progress controls.
Thus, EPA conducted visibility improvement modeling for Dave Johnston
Units 1 and 2.\40\
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    \40\ A summary of EPA's modeling methodology and results can be
found in the docket under EPA BART and RP Modeling for Wyoming
Sources.
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1. PacifiCorp Dave Johnston--Units 1 and 2
Background
    PacifiCorp's Dave Johnston Power Plant is comprised of four units
burning pulverized subbituminous Powder River Basin coal. Both are
nominal 106 MW pulverized coal-fired units. Unit 1 began operation in
1958 and Unit 2 in 1960.