---------------------------------------------------------------------------

    For states using modeling to determine the applicability of BART to
single sources, the BART Guidelines note that a state must establish a
contribution threshold to assess whether the impact of a single source
is sufficient to cause or contribute to visibility impairment at a
Class I area. The BART Guidelines state that, ``[a] single source that
is responsible for a 1.0 deciview change or more should be considered
to `cause' visibility impairment.'' \84\ The BART Guidelines also state
that ``the appropriate threshold for determining whether a source
contributes to visibility impairment may reasonably differ across
states,'' but, ``[a]s a general matter, any threshold that you use for
determining whether a source `contributes' to visibility impairment
should not be higher than 0.5 deciviews.'' \85\ Further, in setting a
contribution threshold, states should ``consider the number of
emissions sources affecting the Class I areas at issue and the
magnitude of the individual sources' impacts. For determining whether a
source is subject to BART, ADEQ used a contribution threshold of 0.5
dv, based on a 3-year average of 98th percentile impacts.
---------------------------------------------------------------------------

    \84\ 40 CFR part 51, appendix Y, section III.A.1.
    \85\ Id.
---------------------------------------------------------------------------

    The BART Guidelines provide that states may choose to use the
CALPUFF modeling system or another appropriate model to predict the
visibility impacts from a single source on a Class I area, and
determine whether an individual source is anticipated to cause or
contribute to impairment of visibility in Class I areas (i.e.,
visibility impacts below the 0.5 dv threshold). The Guidelines state
that we believe CALPUFF is the best regulatory modeling application
currently available for predicting a single source's contribution to
visibility impairment.\86\ The WRAP Regional Modeling Center (RMC)
developed a modeling protocol, entitled ``CALMET/CALPUFF Protocol for
BART Exemption Screening Analysis for Class I Areas in the Western
United States.'' The WRAP RMC used this protocol to perform CALPUFF
modeling for each of the western states in which it assessed the
visibility impact of each of the sources initially identified as BART-
eligible by the SSJF. Certain sources that were identified as causing
or contributing to Class I visibility impairment (and therefore subject
to BART) based on WRAP RMC results performed their own CALPUFF modeling
in order to provide results indicating they were not subject to BART.
This modeling was performed in accordance with the WRAP protocol and
primarily consisted of different estimates of source emission rates
during the baseline period.
---------------------------------------------------------------------------

    \86\ 70 FR 39162.
---------------------------------------------------------------------------

    Based on CALPUFF modeling performed in accordance with the WRAP
protocol, ADEQ determined that the facilities in Table 10 had
visibility impacts below the contribution threshold of 0.5 dv, and were
therefore exempt from BART.

                                    Table 10--Sources Exempt From BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
                                                               Visibility impact at 98th percentile (dv)
              Facility                   Class I area with   --------------------------------------------  Notes
                                          highest impact         2001       2002       2003     Average
----------------------------------------------------------------------------------------------------------------
Nelson Lime Plant...................  Grand Canyon National       0.452      0.419      0.624      0.498       1
                                       Park.
West Phoenix Power Plant............  Superstition                0.28       0.21       0.23       0.24        2
                                       Wilderness.
Rillito Cement Plant................  Saguaro National            0.37       0.48       0.34       0.40        3
                                       Monument.
----------------------------------------------------------------------------------------------------------------
\1\ Based on September 21, 2007 modeling report provided by Chemical Lime.
\2\ Based on October 4, 2007 modeling report provided by Arizona Public Service.
\3\ Based on May 25, 2007 WRAP RMC BART Modeling Results for Arizona.

    Based upon CALPUFF modeling performed by WRAP, the remaining BART-
eligible sources from Table 9 were determined to have visibility
impacts greater than 0.5 dv.
4. Sources Subject to BART in Arizona
    Following the elimination of those sources that it determined were
not BART-eligible or that it found to have visibility impacts below the
0.5 dv contribution threshold, ADEQ determined that the remaining BART-
eligible sources were subject to BART for the one or more pollutants.
These sources are summarized in Table 11.

                                    Table 11--Sources Subject to BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
                                                                                Pollutants
             Facility                   BART emission units           Source category             evaluated
----------------------------------------------------------------------------------------------------------------
Catalyst Paper....................  Power Boiler 2............  Fossil-fuel boilers of      NOX, SO2.
                                                                 more than 250 million
                                                                 British thermal units per
                                                                 hour heat input.
Hayden Smelter....................  Anode Furnaces 1 and 2,     Primary Copper Smelter....  SO2.
                                     Converters 1, 2, and 4.
Miami Smelter.....................  Converters 1-5, Anode       ..........................  SO2, PM10.
                                     Furnace, Shaft Furnace,
                                     Fugitives.
----------------------------------------------------------------------------------------------------------------

    A summary of the BART-eligible sources ADEQ determined not subject
to BART is in Table 12 below.

                                  Table 12--Sources Not Subject to BART (ADEQ)
----------------------------------------------------------------------------------------------------------------
           Facility name                        Source category                            Reason
----------------------------------------------------------------------------------------------------------------
Sundt..............................  Fossil-fuel fired steam electric       Unit 3 commenced operation prior to
                                      plants of more than 250 million        August 7, 1962
                                      British thermal units per hour heat   Unit 4 reconstructed after August 7,
                                      input.                                 1977.
West Phoenix Power Plant...........  .....................................  Exempt (visibility impact <0.5 dv).
Rillito Cement Plant...............  Portland cement plant................  Exempt (visibility impact <0.5 dv).
Nelson Lime Plant..................  Lime Plant...........................  Exempt (visibility impact <0.5 dv).
----------------------------------------------------------------------------------------------------------------

B. EPA's Evaluation of ADEQ's Subject-to-BART Analysis

    Hayden Smelter: We propose to approve ADEQ's determination that the
Hayden smelter is a BART-eligible source and that a BART determination
is required for SO2, but is not required for NOX.
We propose to disapprove ADEQ's determination that a BART determination
is not required for PM10. In its SIP submittal, ADEQ
determined that a BART determination for PM10 was not
required because the facility's potential to emit PM10 is
less than 250 tons per year.\87\ This is inconsistent with the Regional
Haze Rule. As defined in the Regional Haze Rule, a BART-eligible
facility is one that, among other criteria, ``has the potential to emit
250 tons per year or more of any air pollutant.'' \88\ Once a facility
has been determined to be BART-eligible, BART must then be determined
for all visibility-impairing pollutants.\89\ However, a state is not
required to make a BART determination for SO2 or for
NOX if a BART eligible source has the potential to emit less
than 40 tons per year of such pollutant(s), or for PM10 if a
BART-eligible source has the potential to emit less than 15 tons per
year of such pollutant.\90\ For Hayden, the potential to emit
PM10 of the BART-eligible sources is 70 tpy.\91\ While we do
not necessarily agree that this figure encompasses the full potential
to emit of all BART-eligible units at Hayden, even ADEQ's estimate of
70 tpy exceeds the PM10 exception threshold of 15 tpy. As a
result, we propose to find that a BART determination for
PM10 is required. We intend to propose BART requirements for
PM10 at Hayden as part of our Phase 3 proposal. At minimum,
we expect that BART would require compliance with the NESHAP MACT
Subpart QQQ control requirements and emission limits.
---------------------------------------------------------------------------

    \87\ Page 23 of 115, Arizona RH SIP, Appendix D. See Docket Item
B-01.
    \88\ 40 CFR 51.301.
    \89\ 40 CFR 51.308(e)(1)(ii).
    \90\ 40 CFR 51.308(e)(1)(ii)(C).
    \91\ Per Table 6.5, Arizona RH SIP, Appendix D. See Docket Item
B-01.
---------------------------------------------------------------------------

    Miami Smelter: We propose to approve ADEQ's determination that the
Miami smelter is a BART-eligible source, and that a BART determination
is required for SO2 and PM10. We propose to
disapprove ADEQ's determination that a BART

determination is not required for NOX. In its SIP submittal,
ADEQ did not address NOX emissions from the Miami smelter.
As part of the visibility modeling performed for the Miami smelter,
WRAP identified an annual NOX emission rate of 158 tpy for
the units constituting the BART-eligible source.\92\ This exceeds the
NOX exception threshold of 40 tpy. As a result, a BART
determination for NOX is required.
---------------------------------------------------------------------------

    \92\ As described in ``Summary of WRAP RMC BART Modeling for
Arizona'', Draft5, May 25, 2007.
---------------------------------------------------------------------------

    Sundt: We propose to approve ADEQ's determination that Sundt Unit
I3 is not BART-eligible based on the startup date prior to August 7,
1962. We propose to disapprove ADEQ's determination that Sundt Unit I4
is not BART-eligible. Although we accept that the unit was
reconstructed in 1987, we have determined that because the unit did not
undergo PSD review as part of reconstruction that it is subject to
BART.
    Under the RHR, ``BART-eligible source'' means any stationary source
of air pollutants in one the 26 BART categories, ``including any
reconstructed source, which was not in operation prior to August 7,
1962, and was in existence on August 7, 1977, and has the potential to
emit 250 tons per year or more of any air pollutant. * * *'' \93\ As
ADEQ noted in its RH SIP, the BART Guidelines state:
---------------------------------------------------------------------------

    \93\ 40 CFR 51.301.

    The ``in operation'' and ``in existence'' tests apply to
reconstructed sources. If an emissions unit was reconstructed and
began actual operation before August 7, 1962, it is not BART-
eligible. Similarly, any emissions unit for which a reconstruction
``commenced'' after August 7, 1977, is not BART-eligible.\94\
---------------------------------------------------------------------------

    \94\ 40 CFR part 51, appendix Y, Sec.  II.A.2, ``What does `in
existence on August 7, 1977' mean?''

    However, as explained in the preamble to the Guidelines, Congress
intended ``that the BART provision apply to sources which had been
`grandfathered' from the new source review permit requirements in parts
C and D of title I of the CAA.'' \95\ Consistent with this approach,
footnote 9 of the preamble to the BART Guidelines notes that, ``sources
reconstructed after 1977, which reconstruction had gone through NSR/PSD
permitting, are not BART-eligible.'' \96\ By implication, reconstructed
sources that did not go through NSR/PSD permitting, are BART-eligible.
Therefore, EPA concludes that, even accepting ADEQ's determination that
TEP Sundt Unit I4 was ``reconstructed'' after August 7, 1977, the Unit
remains BART-eligible because it did not go through NSR/PSD
permitting.\97\
---------------------------------------------------------------------------

    \95\ 70 FR at 39111.
    \96\ 70 FR at 39111 (July 6, 2005) (emphasis added).
    \97\ See ``TEP Sundt Unit I4 BART Eligibility Memo'' (November
21, 2012) for a more detailed discussion of the BART eligibility of
Unit I4.
---------------------------------------------------------------------------

    Threshold for Subject-to-BART: Arizona set a 0.5 dv as the
threshold for determining whether a source ``contributes'' to
visibility impairment. The BART Guidelines state that ``[as] a general
matter, any threshold that you use for determining whether a source
`contributes' to visibility impairment should not be higher than 0.5
deciviews.\98\ In setting a threshold, states should consider the
number of BART-eligible sources within the state and the magnitude of
each source's impacts.\99\ Arizona did not provide a rationale for
choosing 0.5 dv as the threshold for determining BART eligibility. We
note that the WRAP's SSJF identified fourteen sources that it initially
considered BART eligible, and that ADEQ determined that seven of these
fourteen do not contribute to visibility impairment based on visibility
impacts below 0.5 dv. The source with a modeled impact closest to the
0.5 dv threshold is the Chemical Nelson Lime Plant facility with a
modeled average 98th high impact of 0.498 dv at Grand Canyon NP.\100\
As we discuss below, this is very close to the 0.5 dv threshold and,
depending on how that threshold is interpreted, may exceed it. The
source with the next highest impact is Rillito Cement Plant with a
modeled maximum impact of 0.40 dv at Saguaro NP.\101\ The source with
the next highest impact is Salt River Project San Tan with a modeled
maximum impact of 0.31 dv at Superstition WA. Given that reducing the
threshold to 0.3 dv would not result in bringing into BART a
significant number of sources impacting the same Class I area, the use
of the 0.5 dv threshold may be appropriate. Therefore, EPA proposes to
approve Arizona's decision to set 0.5 dv as the threshold for
determining whether sources are subject-to-BART. However, given that
the modeled average 98th high impact of one BART-eligible source, the
Nelson Lime Plant, is within 0.002 dv of 0.5 dv, EPA is also seeking
comment on whether it was unreasonable for ADEQ to set a threshold of
0.5 dv. If, after taking into consideration any comments received, we
determine that the State's determination was unreasonable, then we may
disapprove the State's decision to set a threshold of 0.5 dv.
---------------------------------------------------------------------------

    \98\ BART Guidelines, 40 CFR part 51, appendix Y, section
III.A.1.
    \99\ Id.
    \100\ From visibility modeling performed by the source, see ARHP
Appendix D, Table 6.9.
    \101\ See ``Summary of WRAP RMC BART Modeling for Arizona''
Draft No. 5, May 7, 2005. Initial draft released on April 4, 2005.
---------------------------------------------------------------------------

    West Phoenix Power Plant: As seen in Table 10, the visibility
modeling performed by APS indicates that the 98th percentile impact
from the West Phoenix Power Plant is below 0.5 dv at the most affected
Class I area. Based on our review of the visibility modeling performed
by APS, we propose to approve ADEQ's determination that the West
Phoenix Power Plant is exempt from BART.
    Rillito Cement Plant: As seen in Table 10, the visibility modeling
performed by CalPortland indicates that the 98th percentile impact from
the Kiln 4 at the Rillito Cement Plant is below 0.5 dv at the most
affected Class I area. Based on our review of the visibility modeling,
we propose to approve ADEQ's determination that the Rillito Cement
Plant is exempt from BART.
    Nelson Lime Plant: As seen in Table 10, the visibility modeling
performed by Chemical Lime indicates that the average 98th percentile
impact from the Nelson Lime Plant is below 0.5 dv at the most affected
Class I area. However the 98th percentile impact for a single year,
2003, exceeds 0.5 dv. ADEQ based its BART-exemption determination on
the 3-year average of 98th percentile impact. When the 2003 value is
averaged with the 2001 and 2002 values, the facility's visibility
impact is below the exemption threshold of 0.5 dv. This interpretation
of the 0.5 dv threshold differs from the interpretation used in a
similar type of analysis, namely the Prevention of Significant
Deterioration (PSD) Class I visibility analysis. For example, the
CALPUFF model is often used for certain aspects of the PSD Class I
visibility analysis, and the Federal Land Managers (FLMs), who have the
affirmative responsibility to protect visibility at Class I areas, also
use 0.5 dv as a threshold.\102\ Guidance issued by the FLMs indicates
that they interpret this threshold to be exceeded if the 98th
percentile values for change in light extinction are equal to or
greater than 0.5 dv for any year.\103\ Typically, the PSD-style method
has been used to determine if a source exceeds the BART threshold.
However, the BART Guidelines and the preamble to the Regional Haze Rule
do not specify the

interpretation of this threshold to the same level of detail as the
FLM's guidance for the PSD program, nor do they specify a rounding
convention under these circumstances. Nonetheless, in this instance,
given that the 98th percentile impact for a single year clearly exceeds
0.5 dv and that the average of the three years is within 0.002 dv of
0.5 dv, EPA proposes to determine that it was not reasonable for the
State to find the Nelson Lime Plant is not subject to BART. Therefore,
we propose to disapprove the State's determination and find that Nelson
Lime Plant is subject to BART. However, we are seeking comment on
whether the State's decision was, in fact, reasonable and should be
approved. If, based on comments received, we determine that the State's
determination was reasonable, then we may approve the State's decision
to find this source not subject-to-BART. In addition, EPA also seeks
comments on whether there are cost effective pollution controls at
Nelson Lime Plant.
---------------------------------------------------------------------------

    \102\ Specifically, the FLM's threshold for concern is a 5%
change in light extinction, which is equivalent to 0.5 dv.
    \103\ Federal Land Managers' Air Quality Related Values Work
Group (FLAG) Phase I Report--Revised (2010) (FLAG 2010), Page 23.
---------------------------------------------------------------------------

    Cholla Unit 1: As discussed previously, we have addressed the BART
determinations for Cholla Units 2, 3, and 4 in a separate action. For
Unit 1, ADEQ determined it is not BART-eligible because it was in
existence prior to August 7, 1962. The WRAP's ``Arizona BART
Eligibility TSD'' further explains that:

    [Cholla] Unit 1 is listed as potentially date eligible as
information shows that the emissions unit was in service only 2
months prior to the cut-off date. Recommend requesting additional
supporting documentation for final determination.\104\
---------------------------------------------------------------------------

    \104\ ``Supporting Documentation on Emissions Unit Bart
Eligibility Analysis'', section 5.1.2.

    ADEQ requested and later received this additional documentation
from APS in August 2007 in the form of a document dated May 23, 1962
entitled ``Operating Notes For May 1962.'' \105\ This document
indicates that, ``[o]n Tuesday, May 1, 1962, unit [1 was]
placed into commercial operation.'' \106\ After reviewing this
documentation, ADEQ concurred that Unit 1 was not BART eligible.\107\
We have requested and received from APS a copy of the ``Operating Notes
For May 1962'' along with additional information concerning the
operation of Cholla Unit 1.\108\ We have placed these materials in the
docket and, based on our review, we consider this documentation to be
sufficient to confirm ADEQ's determination that this unit is not BART-
eligible. As a result, we propose to approve ADEQ's determination that
Cholla Unit 1 is not among the units that constitute the BART-eligible
source at Cholla.
---------------------------------------------------------------------------

    \105\ Arizona Regional Haze SIP at page 155.
    \106\ Id.
    \107\ Id.
    \108\ Email from Sue Kidd, APS, to Colleen McKaughan, EPA
(October 10, 2012, 9:17 a.m.) and attachments.
---------------------------------------------------------------------------

C. Arizona's BART Control Analysis

    The third step of the BART process is to perform the BART analysis
and make a final determination. The BART Guidelines (70 FR 39164)
describe a step-by-step procedure for performing the BART analysis. In
performing this analysis, 40 CFR 51.308(e)(1)(ii)(A) requires that
states consider the following factors: (1) The costs of compliance of
each technically feasible control technology, (2) the energy and non-
air quality environmental impacts of compliance of the control
technologies, (3) any existing pollution control technology in use at
the source, (4) the remaining useful life of the source, and (5) the
degree of improvement in visibility which may reasonably be anticipated
to result from the use of such technology. These factors are frequently
referred to as the ``five-factor analysis'' for the RHR BART
determination.
    The BART Guidelines recommend that a BART analysis include the
following five steps. The Guidelines provide detailed instructions on
how to perform each of these steps.\109\
---------------------------------------------------------------------------

    \109\ 40 CFR part 51, appendix Y, Sec.  IV.D.
---------------------------------------------------------------------------

     Step 1--Identify All Available Retrofit Control
Technologies,
     Step 2--Eliminate Technically Infeasible Options,
     Step 3--Evaluate Control Effectiveness of Remaining
Control Technologies,
     Step 4--Evaluate Impacts and Document the Results,\110\
and
---------------------------------------------------------------------------

    \110\ Step 4 includes evaluating the cost of compliance, energy
impacts, non-air quality environmental impacts, and remaining useful
life.
---------------------------------------------------------------------------

     Step 5--Evaluate Visibility Impacts.
    ADEQ's BART analyses mostly followed this approach, with the
addition of a step to identify existing control technologies and a step
concluding ``selection of BART.'' ADEQ identified a seven step process
in its SIP submittal for determining BART:
     Step 1: Identify the Existing Control Technologies in Use
at the Source
     Step 2: Identify All Available Retrofit Control Options
     Step 3: Eliminate All Technically Infeasible Control
Options
     Step 4: Evaluate Control Effectiveness of Remaining
Technologies
     Step 5: Evaluate the Energy and Non-Air Quality
Environmental Impacts and Document Results \111\
---------------------------------------------------------------------------

    \111\ We note that, while ADEQ refers to its Step 5 as an
evaluation of energy and non-air quality environmental impacts, this
step also includes consideration of the costs of compliance and the
remaining useful life of the source, consistent with the BART
Guidelines, 40 CFR part 51, appendix Y, section IV.D.4.
---------------------------------------------------------------------------

     Step 6: Evaluate Visibility Impacts
     Step 7: Select BART

In the cases of the Hayden and Miami smelters, ADEQ performed a
streamlined BART analysis in which it examined controls required by New
Source Performance Standards (NSPS) and National Emission Standards for
Hazardous Air Pollutants. In the case of PM10, ADEQ examined
control requirements from NESHAP Maximum Achievable Control Technology
(MACT) Subpart QQQ (Primary Copper Smelters) in its streamlined
analysis. In the case of SO2, ADEQ examined control
requirements from NSPS Subpart P (Primary Copper Smelters).
    EPA Evaluation: This seven step BART determination process was also
used to determine BART for the Apache, Cholla, and Coronado. As noticed
in the separate action addressing BART for these facilities, while we
found that this overall approach to the five-factor analysis is
generally reasonable and consistent with the RHR and the BART
Guidelines, we identified certain areas of this approach that were not
consistent with RHR and the BART Guidelines.\112\ This process was used
for the BART determination for Catalyst Paper. However, as explained in
further detail below, we are not proposing to take action on the
facility's BART determinations at this time. As a result, we are not
taking action to identify any areas of the BART determination process
for Catalyst Paper that may not be consistent with RHR.
---------------------------------------------------------------------------

    \112\ 77 FR 42841.
---------------------------------------------------------------------------

    We propose to approve the use of a streamlined BART analysis for
the copper smelters. The use of such a streamlined analysis is
consistent with the RHR, which provides for streamlined analyses in
certain instances when the affected source is subject to a MACT
standard or other emission limitation required under the Clean Air Act.
Our evaluation of the streamlined analyses and resulting determinations
for the smelters are discussed in further detail below.

D. Arizona's BART Determinations

    A summary of the ADEQ's BART determinations is contained in Table
13. Our evaluation of ADEQ's BART determinations is organized by
source.

                                                   Table 13--Summary of Arizona's BART Determinations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 NOX                                PM10                               SO2
                                                --------------------------------------------------------------------------------------------------------
           Unit No.               Description                       Emission limit                      Emission limit                    Emission limit
                                                     Controls          lb/MMBtu          Controls          lb/MMBtu         Controls         lb/MMBtu
--------------------------------------------------------------------------------------------------------------------------------------------------------
Catalyt Paper, Unit 2........  1132 MMBtu/hr     No controls       0.7.............                 None                Partial FGD      0.80
                                Coal-fired        (existing).                                                            (existing).
                                Boiler.
Hayden Smelter...............  3 converters and                 None
                                2 anode
                                smelters.
                                              None
                                     Existing Controls--NSPS
Miami Smelter................  Electric                         None
                                furnace, 4
                                converters,
                                remelt/mold
                                pouring vessel.
                                    Existing Controls--NESHAP
                                     Existing Controls--NSPS
--------------------------------------------------------------------------------------------------------------------------------------------------------

 1. Catalyst Paper
    On July 30, 2012, Catalyst Paper publicly announced the permanent
closure of the mill in Snowflake, which includes the Unit 2 power
boiler.\113\ At present, however, Catalyst Paper has not yet canceled
its operating permits and therefore still maintains the ability to
operate the mill. For this reason, we are not proposing to take action
on ADEQ's BART determinations for Catalyst Paper. Instead, we intend to
require that Catalyst Paper notify us prior to resuming operation of
mill, at which point we will review ADEQ's BART determination and, if
necessary, propose a FIP in accordance with regional haze requirements,
including the BART provisions in 40 CFR 51.308(e).
---------------------------------------------------------------------------

    \113\ http://catalystpaper.com/media/news/community/catalyst-permanently-close-snowflake-recycle-paper-mill.
---------------------------------------------------------------------------

2. Miami Smelter
    ADEQ's Analysis: For PM10, ADEQ performed a streamlined
analysis in which it examined cost information and control requirements
associated with NESHAP MACT Subpart QQQ (Primary Copper Smelters),
which uses PM10 as a surrogate for certain particulate HAP
emissions. ADEQ notes that there are currently three operating copper
smelters: the Kennecott smelter in Utah, the ASARCO smelter in Hayden,
Arizona, and the Freeport McMoRan Inc. smelter in Miami, Arizona, with
the other previously operating facilities having been shut down or
permanently dismantled. ADEQ noted that the Kennecott smelter was
constructed in the mid-1990s and uses a flash copper converting
technology that allows copper to be produced on a continuous basis.
ADEQ determined that the Kennecott smelter is not comparable to the
Miami smelter, which operates as batch process rather than as a
continuous process. A review of EPA's RACT/BACT/LAER Clearinghouse
(RBLC) revealed that there are no emission limitations or air pollution
control devices that have been approved for anode furnace operations.
As a result, ADEQ determined that the most stringent control available
to control PM10 emissions from primary copper smelting are
those required by NESHAP MACT Subpart QQQ.
    For SO2, ADEQ indicated it had performed a
``streamlined'' BART determination in which it examined control
requirements and emission standards associated with NSPS Subpart P
(Primary Copper Smelters). Again, ADEQ noted that only three copper
smelters are currently operating: the Kennecott smelter in Utah, the in
Hayden smelter and the Miami smelter, with the other facilities having
been shut down or permanently dismantled. Again, ADEQ also noted that
the Kennecott smelter was constructed in the mid 1990s and uses a flash
copper converting technology that allows copper to be produced on a
continuous basis. ADEQ determined that the Kennecott smelter is not
comparable to the ASARCO Hayden smelter, which operates as a batch
process rather than as a continuous process. ADEQ reviewed EPA's RBLC
and concluded that there are no emission limitations or air pollution
control devices that have been required as BACT or LAER for anode
furnace operations. Based only on this limited information, ADEQ's
streamlined analysis found that the most stringent control available
for SO2 emissions from primary copper smelting operations is
the existing double contact acid plant and that compliance with NSPS
Subpart P constitutes BART for SO2.
    EPA's Evaluation: We propose to approve ADEQ's BART determination
for PM10 at the Miami smelter. As noted in the BART
Guidelines, ``unless there are new technologies subsequent to the MACT
standards which would lead to cost effective increases in the level of
control, you may rely on the MACT standards for purposes of BART.''
\114\ Although MACT Subpart QQQ was promulgated more than 10 years
ago,\115\ we have not identified any new control technologies for the
Miami smelter that would achieve more stringent emission control. In
addition, we consider ADEQ's exclusion of controls in place at the
Kennecott smelter from consideration to be appropriate for purposes of
BART.\116\ The BART Guidelines state that ``[w]e do not consider BART
as a requirement to redesign the source when considering available
control alternatives.'' \117\ Given the fundamental differences between
operating a copper smelter (or any kind of manufacturing unit) as a
batch process and a continuous process, we do not consider it
appropriate to include this as a potential control option.
---------------------------------------------------------------------------

    \114\ 40 CFR part 51, appendix Y, section IV.C.
    \115\ 67 FR 40478 (June 12, 2002) (codified at 40 CFR part 63,
subpart QQQ).
    \116\ This conclusion does not impact whether or not the level
of control for Kennecott should be considered in a best available
control technology analysis under the Act's prevention of
significant deterioration program.
    \117\ 40 CFR part 51, appendix Y, section IV.D.5.
---------------------------------------------------------------------------

    At this time, we are proposing to disapprove ADEQ's SO2
BART determination or, in the alternative, approve the SO2
BART determination if we receive adequate additional information during
the comment period to support the appropriateness of the streamlined
analysis in the SIP and that the control requirements and emissions
standards from NSPS Subpart P are enforceable at all units as BART. We
agree with ADEQ that the Miami smelter is comparable only to the Hayden
smelter. We also note that the Miami

smelter is operating the sulfuric acid plant at the facility as a
control device rather than as a stand-alone facility.
    The BART Guidelines allow streamlined analyses that rely on
emission standards established under other provisions of the CAA. For
example, the BART Guidelines provide that generally states may rely on
MACT standards for purposes of BART (70 FR 39164), but should consider
other standards, such as the NSPS, only as starting points in
streamlined analyses.\118\ When relying upon an NSPS in performing a
streamlined analysis, the BART Guidelines indicate that additional
analysis must be performed to determine if better control technology
performance can be achieved since the promulgation of the NSPS. The
BART Guidelines state ``where you are relying on these standards to
represent a BART level of control, you should provide the public with a
discussion of whether any new technologies have subsequently become
available.''
---------------------------------------------------------------------------

    \118\ BART Guidelines, 40 CFR part 51, appendix Y, section
IV.D.1, stating: ``[w]e do not believe that technology
determinations from the 1970s or early 1980s, including new source
performance standards (NSPS), should be considered to represent best
control for existing sources, as best control levels for recent
plant retrofits are more stringent than these older levels.''
---------------------------------------------------------------------------

    We are proposing to disapprove ADEQ's BART determination, in part,
because ADEQ did not provide information demonstrating that NSPS
Subpart P meets the requirements for a streamlined BART determination.
At the time NSPS Subpart P was promulgated, the control technology
known to be capable of meeting the SO2 standard was a
sulfuric acid plant, which is the current control technology in place
at the Miami smelter. ADEQ did not analyze whether the acid plant was
operating at an optimal control level or if it could be retrofitted to
operate at a lower emissions level. ADEQ identified the flash copper
converting technology in place at the Kennecott smelter, but
appropriately excluded it from consideration as a control option.\119\
However, we find that it was not reasonable for ADEQ to limit its
analysis to those facilities that are specifically subject to the NSPS
Subpart P, rather than considering emission levels that are being
achieved at other acid plants.
---------------------------------------------------------------------------

    \119\ We consider ADEQ's decision to not consider this
technology to be appropriate. The BART Guidelines state that ``[w]e
do not consider BART as a requirement to redesign the source when
considering available control alternatives.'' \119\ Given the
fundamental differences between operating a copper smelter (or any
kind of manufacturing unit) as a batch process and a continuous
process, we do not consider it appropriate to include this as a
potential control option. As a result, we conclude that in this
instance, ADEQ's reliance on NSPS Subpart P in its streamlined
analysis was appropriate.
---------------------------------------------------------------------------

    ADEQ's analysis did not examine whether acid plants in operation at
a copper smelter (either at Miami or at Hayden) have demonstrated an
ability to achieve, in practice, better levels of control since the
promulgation of NSPS Subpart P. We note that multiple industries
operate acid plants. An acid plant at a copper smelter, for example,
uses the SO2 in process offgas to produce sulfuric acid
product, whereas an acid plant at a stand-alone sulfuric acid plant,
for example, may use SO2 from elemental sulfur and from
spent sulfuric acid to produce sulfuric acid product. However,
regardless of the source of the sulfur or the physical location of the
plant, both facilities may be using the double contact acid plant
process in which SO2 in the feed stream is converted to
SO3 through double contact/double absorption converters.
ADEQ has not provided any basis for limiting its examination of acid
plant performance to only those acid plants operating at copper
smelters.
    In addition, ADEQ does not specify whether its BART determination
would require that all of the BART-subject gas streams at the Miami
smelter meet all of the relevant control requirements and emissions
standards in Subpart P. NSPS Subpart P provides that no owner or
operator of an affected facility ``shall cause to be discharged into
the atmosphere * * * any gases which contain sulfur dioxide in excess
of 0.065 percent by volume.'' \120\ This requirement extends to all of
the emissions released by the subject facilities, which include
smelting furnaces and copper converters, and not just to those
emissions that are vented to and controlled by an acid plant. To
provide an adequate BART determination, ADEQ should include a finding
about the amount of emissions being controlled by the acid plant and a
clarification that the NSPS would apply to all emissions discharged
from the BART-eligible units to the atmosphere.
---------------------------------------------------------------------------

    \120\ 40 CFR 60.163(a).
---------------------------------------------------------------------------

    Therefore, we are proposing to disapprove ADEQ's streamlined
determination that SO2 BART is the existing double contact
acid plant with the NSPS Subpart P emission standard of 650 ppm. We are
disapproving this determination because ADEQ's streamlined analysis
does not demonstrate that the NSPS Subpart P level of control
represents the best level of control. We are also proposing to
disapprove the BART determination because it does not require that all
of the BART-eligible units meet the control requirements and emissions
standards in NSPS Subpart P. Finally, we are proposing to disapprove
the lack of enforceability and compliance requirements for this BART
determination.
    In the alternative, we are proposing to approve ADEQ's
determination that compliance with NSPS Subpart P constitutes BART for
SO2 provided ADEQ or other commenters submit additional
information demonstrating that the sulfuric acid plant cannot achieve a
lower level of SO2 emissions. ADEQ's use of NSPS Subpart P
in its streamlined analysis must be supported by additional information
because, while the BART Guidelines provide that states generally may
rely on MACT standards for purposes of BART, the same is not true for
NSPS standards. NSPS standards may be outdated and may not represent
current pollution control technology performance from acid plants
operating at smelters and other industries.\121\ As a result, we
propose to approve ADEQ's reliance on NSPS Subpart P in its streamlined
analysis as a starting point provided we receive additional information
showing the emission limit remains the most appropriate as BART, that
the sulfuric acid plant cannot be operated cost-effectively at a lower
level of SO2 emissions, and that all other SO2
emissions from the BART-eligible units meet BART. Commenters should not
rely solely on the information regarding copper smelters in the RBLC
but should include information from other acid gas plants.
---------------------------------------------------------------------------

    \121\ BART Guidelines, 40 CFR part 51, appendix Y, section
IV.D.1, n. 13, stating: ``EPA no longer concludes that the NSPS
level of controls automatically represents `the best these sources
can install.' ''
---------------------------------------------------------------------------

    Finally, Regional Haze SIPs must include requirements to ensure
that BART emission limits are enforceable. In particular, the RHR
requires inclusion of (1) A schedule for compliance with BART emission
limitations for each source subject to BART; (2) a requirement for each
BART source to maintain the relevant control equipment and (3)
procedures to ensure control equipment is properly operated and
maintained.\122\ General SIP requirements also mandate that the SIP
include all regulatory requirements related to monitoring,
recordkeeping and reporting for the BART emissions limitations.\123\
ADEQ did not provide any explanation of how the Arizona SIP addresses
these requirements for the

Miami smelter.\124\ Therefore, we can fully approve ADEQ's BART
determinations for this source only if they are accompanied by adequate
compliance requirements, including a clearly defined scope for the
applicable BART requirements, compliance deadlines, operation and
maintenance procedures, and monitoring, recordkeeping and reporting
requirements for all of the BART-eligible units.\125\
---------------------------------------------------------------------------

    \122\ 40 CFR 51.308(e)(1)(iv), (v).
    \123\ See, e.g. CAA section 110(a)(2)(F) and 40 CFR 51.212(c).
    \124\ NSPS Subpart P includes some provisions concerning
monitoring, recordkeeping and reporting but ADEQ did not indicate
whether its BART determination would require compliance with these
provisions. EPA is also aware that the Arizona SIP currently
includes R18-2-175. Standards of Performance for Existing Primary
Copper Smelters; Site Specific Requirements. This SIP-approved rule
contains requirements for the Miami smelter, including enforcement
and compliance provisions. ADEQ did not demonstrate that compliance
with this rule would constitute BART for the Miami smelter.
    \125\ We also note that our proposed approval, in the
alternative, for regional haze requirements purposes should not be
taken as a statement regarding the acceptability of this level of
SO2 emissions at this facility or as an indication of the
facility's compliance with other regulatory requirements. In
addition, we wish to clarify that if we receive additional
information adequate to finalize our proposed approval for BART for
SO2, the BART determination does not foreclose a more
stringent BACT limitation should this source be required to obtain a
PSD permit in the future for any reason.
---------------------------------------------------------------------------

3. Hayden Smelter
    ADEQ's Analysis: For SO2, ADEQ identified some existing
control technologies (i.e., primary and secondary hooding, double
contact acid plant) currently installed and operating for the units
that comprise the BART-subject source at the Hayden smelter. ADEQ
indicated it had performed a ``streamlined'' BART determination in
which it examined control requirements and emission standards
associated with NSPS Subpart P (Primary Copper Smelters). ADEQ noted
that only three primary copper smelting facilities are currently
operating: the Kennecott smelter in Utah, the ASARCO smelter in Hayden,
Arizona, and the Freeport McMoRan Inc. smelter in Miami, Arizona. In
addition, ADEQ also noted that the Kennecott smelter was constructed in
the mid 1990s and uses a flash copper converting technology that allows
copper to be produced on a continuous basis. ADEQ determined the
Kennecott smelter was not comparable to the Hayden smelter, which
operates a batch process rather than a continuous process. ADEQ
reviewed EPA's RBLC and concluded that there are no emission
limitations or air pollution control devices that have been required as
BACT or LAER for anode furnace operations. Based only on this limited
information, ADEQ's streamlined analysis found that the most stringent
control available for SO2 emissions from primary copper
smelting operations is the existing double contact acid plant and that
compliance with NSPS Subpart P constitutes BART for SO2.
    EPA's Evaluation: At this time, we are proposing to disapprove
ADEQ's BART determination or, in the alternative, to approve the BART
determination, if we receive adequate additional information and
analysis during the comment period to support the appropriateness of
the streamlined analysis in the SIP. We are also proposing to
disapprove the lack of compliance requirements, including a compliance
deadline, operation and maintenance requirements, and monitoring,
recordkeeping and reporting requirements sufficient to ensure that the
BART requirements are enforceable at all units. We agree with ADEQ that
the Hayden smelter is comparable only to the Miami smelter. We also
note that the Hayden smelter is operating the sulfuric acid plant at
the facility as a control device rather than a stand-alone facility.
    The BART Guidelines allow streamlined analyses that rely on
emission standards established under other provisions of the CAA. For
example, the BART Guidelines provide that generally states may rely on
MACT standards for purposes of BART (70 FR 39164), but should consider
other standards, such as the NSPS, only as starting points in
streamlined analyses.\126\ When relying upon an NSPS in performing a
streamlined analysis, the BART Guidelines indicate that additional
analysis must be performed to determine if better control technology
performance can be achieved since the promulgation of the NSPS. The
BART Guidelines state ``where you are relying on these standards to
represent a BART level of control, you should provide the public with a
discussion of whether any new technologies have subsequently become
available.''
---------------------------------------------------------------------------

    \126\ BART Guidelines, 40 CFR part 51, appendix Y, section
IV.D.1, stating: ``[w]e do not believe that technology
determinations from the 1970s or early 1980s, including new source
performance standards (NSPS), should be considered to represent best
control for existing sources, as best control levels for recent
plant retrofits are more stringent than these older levels.''
---------------------------------------------------------------------------

    We are proposing to disapprove ADEQ's BART determination, in part,
because ADEQ did not provide information demonstrating that NSPS
Subpart P meets the requirements for a streamlined BART determination.
At the time NSPS Subpart P was promulgated, the control technology
known to be capable of meeting the SO2 NSPS was an acid
plant, which is the current control technology in place at the Hayden
smelter.\127\ ADEQ did not analyze whether the acid plant was operating
at an optimal control level or if it could be retrofitted to operate at
a lower emissions level. ADEQ identified the flash copper converting
technology in place at the Kennecott smelter, but appropriately
excluded it from consideration as a control option.\128\ However, we
find that it was not reasonable for ADEQ to limit its analysis to those
facilities that are specifically subject to the NSPS Subpart P, rather
than considering emission levels that are being achieved at other acid
plants. In addition, ADEQ's analysis did not examine whether acid
plants in operation at a copper smelter (either at Hayden or at Miami)
have demonstrated an ability to achieve, in practice, better levels of
control since the promulgation of NSPS Subpart P. We note that multiple
industries operate acid plants. An acid plant at a copper smelter, for
example, uses the SO2 in process offgas to produce sulfuric
acid product, whereas an acid plant at a stand-alone sulfuric acid
plant, for example, may use SO2 from elemental sulfur and
from spent sulfuric acid to produce sulfuric acid product. However,
regardless of the source of the sulfur or the physical location of the
plant, both facilities may be using the double contact acid plant
process in which SO2 in the feed stream is converted to
SO3 through double contact/double absorption converters.
ADEQ has not provided any basis for limiting its examination of acid
plant performance to only those acid plants operating at copper
smelters.
---------------------------------------------------------------------------

    \127\ Specifically, ASARCO currently operates a double contact
acid plant, which replaced the original single contact acid plant in
1983.
    \128\ We consider ADEQ's decision to not consider this
technology to be appropriate. The BART Guidelines state that ``[w]e
do not consider BART as a requirement to redesign the source when
considering available control alternatives.'' Given the fundamental
differences between operating a copper smelter (or any kind of
manufacturing unit) as a batch process and a continuous process, we
do not consider it appropriate to include this as a potential
control option. As a result, we conclude that in this instance,
ADEQ's reliance on NSPS Subpart P in its streamlined analysis was
appropriate.
---------------------------------------------------------------------------

    In addition, ADEQ does not specify whether its BART determination
would require that all of the BART-subject gas streams at the Hayden
smelter meet all of the relevant control requirements and emissions
standards in Subpart P. NSPS Subpart P provides that no owner or
operator of an affected facility ``shall cause to be discharged into
the atmosphere * * * any gases which contain sulfur dioxide in excess
of 0.065

percent by volume.'' \129\ This requirement extends to all of the
emissions released by the subject facilities and not just to those
emissions that are vented to and controlled by an acid plant. To
provide an adequate BART determination, ADEQ should include a finding
about the amount of emissions being controlled by the acid plant and a
clarification that the NSPS would apply to all emissions discharged
from the BART-subject units to the atmosphere.
---------------------------------------------------------------------------

    \129\ 40 CFR 60.163(a).
---------------------------------------------------------------------------

    Finally, Regional Haze SIPs must include requirements to ensure
that BART emission limits are enforceable. In particular, the RHR
requires inclusion of (1) A schedule for compliance with BART emission
limitations for each source subject to BART; (2) a requirement for each
BART source to maintain the relevant control equipment and (3)
procedures to ensure control equipment is properly operated and
maintained.\130\ General SIP requirements also mandate that the SIP
include all regulatory requirements related to monitoring,
recordkeeping and reporting for the BART emissions limitations.\131\
ADEQ did not provide any explanation of how the Arizona SIP addresses
these requirements for the Hayden smelter.\132\
---------------------------------------------------------------------------

    \130\ 40 CFR 51.308(e)(1)(iv), (v).
    \131\ See, e.g. CAA section 110(a)(2)(F) and 40 CFR 51.212(c).
    \132\ NSPS Subpart P includes some provisions concerning
monitoring, recordkeeping and reporting but ADEQ did not indicate
whether its BART determination would require compliance with these
provisions. Additionally, ADEQ did not specify when any BART-
eligible units not currently subject to NSPS Subpart P at the Hayden
Smelter would be required to comply with its control requirements
and emissions standards. EPA is also aware that the Arizona SIP
currently includes R18-2-175. Standards of Performance for Existing
Primary Copper Smelters; Site Specific Requirements. This SIP-
approved rule contains requirements for the Miami smelter, including
enforcement and compliance provisions. ADEQ did not demonstrate that
compliance with this rule would constitute BART for the Hayden
smelter.
---------------------------------------------------------------------------

    Therefore, we are proposing to disapprove ADEQ's streamlined
determination that SO2 BART is the existing double contact
acid plant with the NSPS Subpart P emission standard of 650 ppm. We are
disapproving this determination because ADEQ's streamlined analysis
does not demonstrate that the NSPS Subpart P level of control
represents the best level of control. We are also proposing to
disapprove the BART determination because it does not require that all
of the BART-eligible units meet the control requirements and emissions
standards in NSPS Subpart P. Finally, we are proposing to disapprove
the lack of enforceability and compliance requirements for this BART
determination.
    In the alternative, we are proposing to approve ADEQ's
determination that compliance with NSPS Subpart P constitutes BART for
SO2, provided ADEQ or other commenters submit additional
information demonstrating that the sulfuric acid plant cannot achieve a
lower level of SO2 emissions. ADEQ's use of NSPS Subpart P
in its streamlined analysis must be supported by additional information
because, while the BART Guidelines provide that states generally may
rely on MACT standards for purposes of BART, the same is not true for
NSPS standards. NSPS standards may be outdated and may not represent
current pollution control technology performance from acid plants
operating at smelters and other industries.\133\ As a result, we
propose to approve ADEQ's reliance on NSPS Subpart P in its streamlined
analysis as a starting point, provided we receive additional
information showing the emission limit remains the most appropriate as
BART, that the sulfuric acid plant cannot be operated cost-effectively
at a lower level of SO2 emissions, and that all other
SO2 emissions from the BART-eligible units meet BART.
Commenters should not rely solely on the information regarding copper
smelters in the RBLC but should include information from other acid gas
plants.
---------------------------------------------------------------------------

    \133\ BART Guidelines, 40 CFR part 51, appendix Y, section
IV.D.1, n. 13, stating: ``EPA no longer concludes that the NSPS
level of controls automatically represents `the best these sources
can install.' ''
---------------------------------------------------------------------------

    Finally, we can fully approve ADEQ's BART determination for this
source only if ADEQ also submits adequate compliance requirements,
including a clearly defined scope for the applicable NSPS requirements,
compliance deadlines, operation and maintenance procedures, and
monitoring, recordkeeping and reporting requirements.\134\
---------------------------------------------------------------------------

    \134\ We also note that our proposed approval, in the
alternative, for regional haze requirements purposes should not be
taken as a statement regarding the acceptability of this level of
SO2 emissions at this facility or as an indication of the
facility's compliance with other regulatory requirements. In
addition, we wish to clarify that if we receive additional
information adequate to finalize our proposed approval for BART for
SO2, the BART determination does not foreclose a more
stringent BACT limitation should this source be required to obtain a
PSD permit in the future for any reason. Also, EPA is currently
investigating the compliance status of this facility for other
provisions of the CAA.
---------------------------------------------------------------------------

VIII. EPA's Evaluation of Arizona's Reasonable Progress Goals

 A. Reasonable Progress Goals for the Best Days

    The RHR requires that the RPGs ensure that there is no degradation
on the best 20 percent of days.\135\ The projected visibility levels
for 2018 (shown in Table 5) raise some concerns about some of the Class
I areas on the best days. The Class I areas represented by CHIR1 are
projected to have an increase in visibility impairment of 0.03 dv.
Saguaro NP--East Unit (SAGU1) is projected to have an increase of 0.10
dv.
---------------------------------------------------------------------------

    \135\ 40 CFR 51.308(d)(1).
---------------------------------------------------------------------------

    The species-specific results of the 2018 projections provide more
details about what the computer model shows to be the driver of the
apparent increase in degradation at these two monitors. Table 14
provides this data.
---------------------------------------------------------------------------

    \136\ Source: WRAP TSS, http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx, Best 20% of days, (plan02d--rev and
prp18b).

 Table 14--Pollutant-Specific Contribution to Visibility Impairment on the Best 20 Percent of Days at CHIR1 and
                                                   SAGU1 \136\
----------------------------------------------------------------------------------------------------------------
                                                         CHIR1                               SAGU1
                                         -----------------------------------------------------------------------
                                              2000-2004                           2000-2004
                Pollutant                     baseline       2018 projected       baseline       2018 projected
                                           conditions [Mm-   conditions [Mm-   conditions [Mm-   conditions [Mm-
                                                 1]                1]                1]                1]
----------------------------------------------------------------------------------------------------------------
Sulfate.................................              2.28              2.29              2.67              2.65
Nitrate.................................              0.53              0.49              0.99              1.04
Organic Carbon..........................              1.40              1.41              2.18              2.30
Elemental Carbon........................              0.67              0.57              1.27              0.88
Fine Soil...............................              0.33              0.44              1.10              1.77

Coarse Material.........................              1.22   \137\ No change              1.83         No change
Sea Salt................................              0.01         No change              0.11         No change
----------------------------------------------------------------------------------------------------------------

    At both CHIR1 and SAGU1, the increase in visibility impairment is
caused primarily by the projected increase in impairment due to fine
soil.
---------------------------------------------------------------------------

    \137\ WRAP elected to hold the coarse mass and sea salt
visibility impairment levels constant.
---------------------------------------------------------------------------

    The monitoring data trends are not consistent with what the model
is projecting. As shown in the Arizona IMPROVE trend analysis conducted
by EPA,\138\ the monitors representing these areas showed the greatest
improvement in visibility on the worst days when one compares monitored
data in 2005-2010 to monitored data in the base period of 2000-2004.
Significantly, there is no indication of increased impairment due to
fine soil. Given these facts, and the relatively small amount of
projected degradation, EPA is not overly concerned with the model
results.
---------------------------------------------------------------------------

    \138\ See Table 5 of EPA Analysis of IMPROVE Monitoring Data
From 2000-2010 in the docket.
---------------------------------------------------------------------------

    However, these projected visibility conditions on the 20 percent
least impaired days do not account for benefits from EPA's BART
determinations for Apache, Cholla and Coronado.\139\ EPA expects the
visibility on the least impaired days to be better than projected in
the ARHP. Therefore, we propose disapproval of the RPGs for the 20
percent best days.
---------------------------------------------------------------------------

    \139\ 77 FR 72512.
---------------------------------------------------------------------------

 B. Reasonable Progress Goals for the Worst Days

    Because Arizona's RPG estimates provide for a rate of improvement
in visibility slower than the rate needed to show attainment of natural
conditions by 2064, the RHR requires the state to demonstrate why its
RPGs are reasonable and why a rate of progress leading to attainment of
natural visibility conditions by 2064 is not reasonable.\140\ The RHR
specifies that RPGs, as well as the demonstration of the reasonableness
of attainment beyond 2064, are to be established and evaluated taking
into consideration four factors: 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.\141\ As explained below, we propose to find that the State did
not conduct an adequate analysis of these four factors. However, based
on our supplementary analysis, we have come to the same conclusion as
Arizona for some visibility impairing pollutants.
---------------------------------------------------------------------------

    \140\ The RHR also requires that the state provide to the public
an assessment of the number of years it will take to reach natural
visibility conditions. 40 CFR 51.308(d)(1)(ii). Arizona's estimates
were included in its proposed SIP, which was provided to the public
during the public review and comment process prior to ADEQ's
adoption of the ARHP.
    \141\ 40 CFR 51.308(d)(1)(i)(A); 51.308(d)(1)(ii).
---------------------------------------------------------------------------

    Focus on NOX and SO2: The State elected to focus its reasonable
progress analysis on NOX and SO2. EPA concurs
that these are the primary pollutants of concern. EPA also concurs that
it is not appropriate to focus on primary organic aerosols or sources
of VOC emissions at this time. The WRAP emissions inventories
demonstrate that the vast majority of these emissions are not
controllable by the State. However, we disagree with the state's
decision to exclude coarse mass and fine soil from their reasonable
progress analysis. According to the State's own analysis, 57 percent of
coarse mass emissions and 60 percent of fine soil emissions in 2002
were anthropogenic.\142\ We propose to disapprove the State's finding
that it was not reasonable to require additional reductions of coarse
mass or fine soil emissions, given that the State did not conduct an
analysis for these pollutants, given that they contribute significantly
to visibility impairment and are mostly from anthropogenic sources.
---------------------------------------------------------------------------

    \142\ Tables 8.5 and 8.6 of the ARHP.
---------------------------------------------------------------------------

    Mobile Sources: Emissions of SO2, NOX and VOC
from on-road and off-road mobile sources are projected to drop
significantly over the planning period (2002-2018). This is due to the
impact of EPA requirements for cleaner vehicles and cleaner fuels.\143\
Given these large reductions in emissions of these pollutants, we
propose to approve the State's decision to not consider further control
measures for SO2, NOX and VOC from mobile
sources.
---------------------------------------------------------------------------

    \143\ See ARHP page 173.
---------------------------------------------------------------------------

    Fires: EPA proposes to agree with the State that emissions from
fires should not be considered for further controls in the reasonable
progress analysis. Efforts to reduce visibility impacts from fires are
appropriately addressed by the smoke management plans, rather than in a
reasonable progress analysis. EPA's analysis of the smoke management
plans may be found in our evaluation of the State's Long Term Strategy
in Section IX of this plan.
    Area Sources: The State did not complete an adequate analysis of
the potential for reasonable controls from area sources of
NOX and SO2. While a number of source categories
are listed in Chapter 11 of the ARHP, in the case of area sources, the
state typically judged that it was too resource intensive to conduct
the analysis. Given the lack of supporting analysis, the EPA proposes
to disapprove the State's finding that there are no reasonable controls
for NOX or SO2 on area sources.
    Point Sources of SO2: The vast majority of
SO2 emissions in Arizona are from point sources.\144\
Therefore, this is the most important source category to consider for
this pollutant. Over 99 of percent point source SO2
emissions in Arizona are from 10 stationary sources. These sources are
shown in Table 15. Some of these facilities are subject to BART (noted
below). For the others, the State did not adequately consider the
possibility of additional controls, so EPA conducted its own analysis.
---------------------------------------------------------------------------

    \144\ Table 8.1 of the ARHP.

            Table 15--Largest Sources of SO2 in Arizona \145\
------------------------------------------------------------------------
                                                        SO2 emissions in
                        Source                           2002 (tons per
                                                             year)
------------------------------------------------------------------------
Cholla Power Plant...................................             20,770
Tucson Electric Power Springerville..................             19,862
Hayden Smelter.......................................             18,439
Coronado Generating Station..........................             17,741
Miami Smelter........................................              5,667
Apache Generating Station............................              5,167
Sundt Generating Station.............................              3,119
Catalyst Paper Mill..................................              1,519
Nelson Lime Plant....................................                893
Douglas Lime Plant...................................                755
------------------------------------------------------------------------

    The sources that ADEQ found subject to BART are described in
Section VII of this notice. These are: Cholla (Units 2-4 only), Hayden
smelter, Coronado, Miami smelter, Apache plant (Units 1-3 only), and
the Catalyst Paper. EPA is proposing to find that the Sundt Generating
Station Unit 4 is BART-eligible and the Nelson Lime Plant is also
subject to BART.\146\ Therefore, EPA's reasonable progress analysis
will focus on those remaining sources and units that we expect to emit
significant quantities of SO2: TEP Springerville, Sundt
Units 1-3, and the Douglas Lime Plant.\147\ For each source, we have
evaluated each of the four statutory reasonable progress factors. In
addition, where we found that there were additional potentially cost-
effective controls available (using an initial screening level of
$5,000/ton), we conducted visibility modeling to assess the potential
benefits of those controls.\148\ These analyses are set forth in Tables
16A-16C below.
---------------------------------------------------------------------------

    \145\ Source: WRAP 2002 Arizona Point Source Emissions.
    \146\ If EPA determines that the Nelson Lime Plant is not
subject-to-BART, we will evaluate it for cost effective
SO2 controls for reasonable progress.
    \147\ We have not considered potential SO2 controls
at Cholla Unit 1 and Apache Unit 4, since these units have
relatively low SO2 emissions. Cholla Unit 1 currently
uses lime injection to remove at least 80 percent of SO2
as a result of New Source Review (Installation Permit 1247)
and Apache Unit 4 may only be operated on pipeline quality natural
gas, except during periods of gas curtailment not to exceed 600
hours per year (title V operating permit 35043). These
permits can be accessed at http://www.azdeq.gov/environ/air/permits/title_v/index.html.
    \148\ While visibility is not an explicitly listed factor to
consider when determining whether additional controls are
reasonable, the point of additional controls is to make reasonable
progress toward natural visibility conditions. Therefore, the
projected visibility benefit of the controls should be taken into
account when determining if the controls are needed to make
reasonable progress.
    \149\ See ``Springerville FGD costs.xls'' for a summary of
preliminary cost estimates.
    \150\ Source: WRAP 2002 Arizona Point Source Emissions.

                Table 16A--SO2 Reasonable Progress Analysis for TEP Springerville (Units 1 and 2)
----------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  These coal-fired units are already equipped with dry flue gas
                                               desulfurization (FGD) units. Therefore, they are already well
                                               controlled for SO2. While it is possible to remove the dry FGD
                                               units and replace them with more effective wet FDG units, we
                                               estimate the incremental cost effectiveness of such an effort to
                                               be approximately $17,000 to $22,000/ton, which is a range of
                                               values that we do not consider cost effective.\149\
Time Necessary for Compliance...............  Any new control device would need to be installed by 2018. There
                                               would be sufficient time to comply.
Energy and Non-Air Quality Environmental      A wet FGD would require more energy than the existing dry FGD. In
 Impacts of Compliance.                        addition, it would create a new water waste stream at the
                                               facility.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given that the facility is already well controlled, EPA proposes
                                               to find that it is not reasonable to require more stringent SO2
                                               controls on this facility at this time.
----------------------------------------------------------------------------------------------------------------

                         Table 16B--SO2 Reasonable Progress Analysis for Sundt Units 1-3
----------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  These units are all fired with pipeline-quality natural gas. Their
                                               SO2 emissions are low and will remain low. 99.9 percent of the
                                               SO2 emissions from this facility are from Unit 4.\150\ Given the
                                               very low emission rates from these units--there are no cost-
                                               effective controls.
Time Necessary for Compliance...............  Any new control device would need to be installed by 2018. There
                                               would be sufficient time to comply.
Energy and Non-Air Quality Environmental      Any post-combustion control, such as FGD would reduce the
 Impacts of Compliance.                        thermodynamic efficiency of the plant and increase fuel
                                               consumption.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given that the low SO2 emissions from this non-BART units at this
                                               facility, EPA proposes to find that it is not reasonable to
                                               require more stringent SO2 controls on this facility at this
                                               time.
----------------------------------------------------------------------------------------------------------------

                       Table 16C--SO2 Reasonable Progress Analysis for Douglas Lime Plant
----------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
Costs of Compliance.........................  Emissions inventory data indicates that production at the Douglas
                                               Lime Plant essentially stopped during the recession. SO2
                                               emissions from the facility were 1,013 tpy in 2008, 42 tpy in
                                               2009 and 0 tpy in 2010. Given the lack of emissions from the
                                               plant, EPA proposes to find that requiring controls would not be
                                               reasonable at this time.
Time Necessary for Compliance...............  Any controls would need to be installed by 2018. There is adequate
                                               time to install controls.
Energy and Non-Air Quality Environmental      A wet FGD would increase energy consumption at the plant and would
 Impacts of Compliance.                        create a new waste water stream.
Remaining Useful Life.......................  EPA assumes that the facility has a remaining useful life in
                                               excess of 20 years, allowing time to amortize the cost of any new
                                               controls.
Conclusion..................................  Given the current lack of SO2 emissions, EPA proposes to find that
                                               it is not reasonable to require additional controls on this plant
                                               at this time. This plant should be considered for SO2 controls in
                                               future planning periods, as it may return to its previous levels
                                               of emissions.
----------------------------------------------------------------------------------------------------------------

    Based on our supplemental analyses provided in the tables above,
EPA proposes to approve ADEQ's conclusion that it is not reasonable to
require additional SO2 controls on non-BART sources at this
time.
    Point Sources of NOX: The State's analysis of point sources to
justify its RPGs did not provide sufficient supporting information to
demonstrate the requirements of the RHR have been met. For example, the
State's analysis of internal combustion engines and combustion turbines
stated that ``the Department has determined that it is not possible to
complete a four-factor analysis without a major investment of resources
* * * which is beyond the scope and effort required in this first
Regional Haze SIP and therefore no further analysis was conducted.''
Similarly, with respect to cement kilns, the ARHP contends that the
Rillito Cement Plant does not ``appreciably diminish or impair
visibility'', but the plan does not provide technical documentation of
that assertion. Given the slow rate of visibility improvement on the
worst days at all Class I areas, a thorough analysis is required before
concluding that nothing more can be done to improve visibility.
Therefore, EPA proposes to disapprove the State's finding that it is
not reasonable to require additional NOX controls on non-
BART point sources in Arizona.

C. Summary of EPA's Evaluation

    EPA proposes to find that State did not demonstrate that its RPGs
for the worst 20 percent of days in 2018 constitute reasonable progress
toward the goal of natural visibility impairment by 2064. Specifically,
EPA proposes to find that the State did not perform an adequate
analysis for reasonable controls for fine soil and coarse mass. EPA
furthermore proposes to find that the State did not perform an adequate
analysis justifying its decision that it is not reasonable to require
additional NOX controls on non-BART point sources. Based on
these shortcomings, EPA proposes to disapprove the State's RPGs for the
worst 20 percent days at all Class I Areas in the state.
    EPA also proposes to disapprove the State's RPGs for the best 20
percent of days. We expect that visibility on these days will be better
than the State projects, given additional controls required by the EPA.

IX. EPA's Evaluation of Arizona's Long-term Strategy

    Under section 51.308(d)(3) of the RHR, Arizona must include a 10 to
15-year long-term strategy (LTS) as part of its regional haze plan
(RHP). Arizona's LTS should compile all control measures the State will
use through 2018 to meet the regional haze plan's RPGs, including BART
required by the RHR. The LTS must include ``enforceable emissions
limitations, compliance schedules, and other measures needed to achieve
the reasonable progress goals'' for all Class I areas within and
affected by emissions from Arizona.\151\ There are five general
requirements for Arizona's LTS. The first general requirement concerns
the interstate consultation process.\152\ The second concerns allotted
emission reductions for out-of-state Class I areas.\153\ A third and
related requirement concerns documenting the technical basis for
determining the apportionment of emission reduction obligations needed
for reasonable progress in reducing visibility impairment in the
State's affected Class I areas.\154\ The fourth general requirement is
to identify anthropogenic emissions sources causing visibility
impairment considered by the State in developing its RHP.\155\ Finally,
the fifth general requirement is for the State to consider the
following factors within the LTS:
---------------------------------------------------------------------------

    \151\ See 40 CFR 51.308(d)(3).
    \152\ See 40 CFR 51.308(d)(3)(i).
    \153\ See 40 CFR 51.308(d)(3)(ii).
    \154\ See 40 CFR 51.308(d)(3)(iii).
    \155\ See 40 CFR 51.308(d) (iv).

    (A) Emission reductions due to ongoing air pollution control
programs, including measures to address reasonably attributable
visibility impairment;
    (B) Measures to mitigate the impacts of construction activities;
    (C) Emissions limitations and schedules for compliance to
achieve the reasonable progress goal;
    (D) Source retirement and replacement schedules;
    (E) Smoke management techniques for agricultural and forestry
management purposes including plans as 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 long-term strategy.\156\
---------------------------------------------------------------------------

    \156\ See 40 CFR 51.308(d)(3)(v).

    We have reviewed Arizona's LTS against these five general
requirements.

 A. Interstate Consultation on Emission Management Strategies

    Under 40 CFR 51.308(d)(3)(i), Arizona is required to consult with
another state if Arizona's emissions are reasonably anticipated to
contribute to visibility impairment at that state's Class I area and
must consult with other states, if emissions from those other states
are reasonably anticipated to contribute to visibility impairment Class
I areas in Arizona. To meet these regulatory requirements for
interstate consultation and coordination, Arizona consulted with other
states and tribes using the WRAP forums and processes. In particular,
Arizona consulted with California, Colorado, New Mexico, and Utah using
the primary vehicle of the WRAP Implementation Work Group (IWG).
Arizona describes their WRAP participation in Chapters 2, 12.2, 13.2,
and Appendix C of the RHP.
    While Nevada was not a formal member of the WRAP and was not listed
with WRAP member states in Arizona's discussion of interstate
consultation, we note that Nevada did participate in WRAP workgroups
and utilized WRAP technical analyses and source apportionment modeling
in producing the Nevada RHP. Nevada used the WRAP's source
apportionment modeling to demonstrate Nevada's minimal contribution of
the State's sulfate and nitrate emissions to light extinction at 25
Class I areas in Nevada's five neighboring states. Based on
consultation through the WRAP, Nevada identified no major contributions
that supported developing new interstate strategies, mitigation
measures, or emissions reduction obligations.\157\
---------------------------------------------------------------------------

    \157\ For our review and discussion of the Nevada RHP and
approval of Nevada's consultation procedures, see our proposed rule
at 76 FR 36450, (June 22, 2011) and our final rule at 77 FR 17334,
(March 26, 2012).
---------------------------------------------------------------------------

    In addition to participating with WRAP member states and Nevada in
the WRAP forums and using WRAP analytical tools and procedures, Arizona
provided a 30 day public comment period and a public hearing on
December 2, 2010 to receive oral and written comments on its proposed
RHP. No other states submitted oral or written comments or requested
additional consultation during Arizona's public review process,
including Nevada. See Appendix E of the RHP for the public hearing
transcript and submitted written comments.

B. Measures To Obtain Allotted Emissions Reductions

    Pursuant to 40 CFR 51.308(d)(3)(ii), Arizona is required to
demonstrate, where its emissions cause or contribute to impairment in
another state's Class I area, that it has included in its RHP all
measures needed to obtain its share of the emission reductions for
meeting the progress goal for that state's Class I area. Also, since
Arizona participated in a regional planning process through the WRAP,
Arizona is required to include in

the LTS all measures needed to achieve its allotment of emission
reductions agreed upon through the WRAP process.\158\
---------------------------------------------------------------------------

    \158\ 40 CFR 51.308(d)(3)(ii).
---------------------------------------------------------------------------

    Arizona's LTS for the first implementation period addresses the
emissions reductions from federal, state, and local controls that take
effect in the State from the end of the baseline period starting in
2002 through 2018.\159\ Coordinating with the WRAP, ADEQ developed its
LTS using the following components: WRAP emission inventories for a
2002 baseline and a 2018 projection (including emission reductions from
WRAP member states); controls required or expected under federal and
state regulations and BART; modeling to determine visibility
improvement and apportion individual state contributions; state
consultation; and application of the long-term strategy factors.
Arizona accepted and incorporated the WRAP-developed visibility
modeling within the ARHP. However, as explained above, we have
disapproved the State's BART determinations for NOX at the
following units: Apache Units 2 and 3; Cholla Units 2, 3, and 4;
Coronado Units 1 and 2.\160\ In addition, as described in section VII
of this document, we are proposing to disapprove certain elements of
the state's BART determinations at other sources. Accordingly, the LTS,
as approved into the applicable Arizona SIP, will not include all of
the emissions reductions that were assumed in the WRAP-developed
visibility modeling. Accordingly, Arizona's LTS does not include all
measures needed to achieve its allotment of emission reductions agreed
upon through the WRAP process. Therefore, we propose to determine that
the LTS does not meet the requirements of 40 CFR 51.308(d)(3)(ii).
---------------------------------------------------------------------------

    \159\ See the ARHP at page 201 for examples of federal and state
programs providing emission reductions; e.g., federal low sulfur
diesel fuel requirement and the Arizona vehicle emissions inspection
program (AVEIP). For our approval of the AVEIP into the Arizona SIP,
see 68 FR 2912; (January 22, 2003). Later in this review, we discuss
several other state and local regulations that have been approved
into the SIP.
    \160\ See our proposed rule at 77 FR 42834, (July 20, 2012) and
our final rule at 77 FR 72512, (December 5, 2012) which addressed
these units.
---------------------------------------------------------------------------

C. Technical Basis for Apportionment of Emission Reductions

    Pursuant to 40 CFR 51.308(d)(3)(iii), Arizona is required to
document the technical basis that it relied upon to determine its share
of emission reduction obligations needed to achieve reasonable progress
in each mandatory Class I Federal area it affects, including modeling,
monitoring, and emissions information. The State may meet this
requirement by relying on technical analyses developed by the WRAP and
approved by all State participants. Arizona must also identify the
baseline emissions inventory on which its strategies are based.
    To meet these requirements, Arizona relied on several WRAP data and
analytical systems and technical centers, such as the Technical Support
System, the Regional Modeling Center, the Visibility Information
Exchange Web System, the Causes of Haze Assessment Project, and the
Emission Data Management System. Arizona provided a general overview of
the WRAP policy and technical assistance in Chapter 12.2 and more
specific and detailed documentation in Appendix C of the ARHP.
Specifically, to determine the significant sources contributing to haze
in Arizona's Class I areas, Arizona 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 of sulfate and nitrate sources. The second
technique was the Weighted Emissions Potential (WEP) tool, used for
attribution of sources of organic carbon, elemental carbon,
PM2.5, and PM10. The WEP tool is based on
emissions and residence time, not modeling. 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. More
information on the WRAP modeling methodologies is available in Appendix
C of the RHP.
    As directed by the WRAP Modeling Forum, the Regional Modeling
Center at the University of California at Riverside performed modeling
for the WRAP member states, including Arizona. The Regional Modeling
Center primarily used the CMAQ photochemical grid model to estimate
2018 visibility conditions in Arizona and all western Class I areas,
based on application of the regional haze strategies in the various
state plans, including assumed controls on BART sources. The Regional
Modeling Center developed air quality modeling inputs, including annual
meteorology and emissions inventories for the following: (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 SMOKE modeling system.
These inventories were revised several times throughout the development
process to arrive at the final versions used in CMAQ modeling. The
photochemical modeling of regional haze for 2002 and 2018 for the WRAP-
member states was conducted on the 36-kilomenter 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. Again, a
more detailed description of the CMAQ modeling performed for the WRAP
can be found in Appendix C of the RHP.
    To summarize, as described in Chapters 11 and 12 and Appendix C of
the ARHP, Arizona used the technical tools and outputs provided by the
WRAP, including the WRAP's 2002 baseline inventory, to produce the
State's LTS. In EPA's evaluation of the WRAP's technical tools, we
found these tools to be adequate for the analytical task to which they
were applied and consistent with EPA guidance and suggested practice at
the time of their use by the WRAP for its member states.\161\
Therefore, we propose to determine that the ARHP meets the requirements
of 40 CFR 51.308(d)(iii).
---------------------------------------------------------------------------

    \161\ See ``Technical Support Document for Technical Products
Prepared by the Western Regional Air Partnership (WRAP) in Support
of Western Regional Haze Plans,'' February 28, 2011, at pages 57-58
for a summary of our review of the WRAP's analytical work.
---------------------------------------------------------------------------

D. Anthropogenic Sources of Visibility Impairment

    Pursuant to 40 CFR 51.308(d)(3)(iv) Arizona is required to identify
all anthropogenic sources of visibility impairment it considered in
developing its LTS, including major and minor stationary sources,
mobile sources, and area sources. As described earlier, Arizona used
emissions inventories for 2002 and 2018 provided by the WRAP. The 2018
emissions inventory was developed by projecting 2002 emissions and
applying reductions expected from federal and state regulations. The
ARHP emission inventories were developed by WRAP and distributed to
Arizona via the Technical Support System. These emission inventories
were calculated using approved EPA methods and we found them to be
adequate for their use by the WRAP.\162\
---------------------------------------------------------------------------

    \162\ We found the WRAP emission inventories to be complete,
recent, and accurate, as well as, consistent with EPA Guidance; see
EPA's February 28, 2011 TSD at page 58.
---------------------------------------------------------------------------

    Across all visibility-related pollutants, there are 11 different
emission

inventory source categories identified in Arizona's RHP: point,
anthropogenic fire, natural fire, area, WRAP region oil and gas, on-
road mobile, off-road mobile, biogenic, road dust, fugitive dust, and
windblown dust. Tables 8.1 through 8.8 of the ARHP show Arizona's 2002
baseline emissions, the 2018 projected emissions, and net changes of
emissions for SO2, NOX, organic carbon, elemental
carbon, PM2.5, PM10, NH3, and VOC by
their respective source category. In our discussion of the ARHP's
emission inventories in section VI, we provide a summary of the
relative contribution of anthropogenic sources for these pollutants;
see Table 7. Furthermore, as part of its reasonable progress
demonstration, Arizona identified the following specific source
categories, totaling 48 facilities, as producing anthropogenic
emissions worthy of consideration: internal combustion engines and
turbines; external combustion boilers; asphalt plants; lime plants;
primary copper smelters; and, nitric acid plants; see chapter 11.3 of
the ARHP. The methods that the WRAP used to develop these emission
inventories are described in more detail in Chapters 8, 9 and Appendix
C of the RHP and are evaluated in the EPA's February 28, 2011 TSD.
    In summary, Arizona utilized the 2002 and 2018 WRAP emission
inventories developed according to EPA guidance and presented those
inventories in the RHP. Also, Arizona identified all anthropogenic
sources of visibility impairment it considered in developing the LTS.
Therefore, we propose to determine that the ARHP meets the requirements
of 40 CFR 51.308(d)(3)(iv). It should be noted that our proposed
approval for this element is based on our finding that Arizona
identified the sources of impairment that it actually considered in
developing the LTS. This proposed approval does not imply that Arizona
fully or appropriately considered all anthropogenic sources of
visibility impairment in establishing its RPGs.

E. Mandatory Factors To Consider for the Long-Term Strategy

    Pursuant to 40 CFR 51.308(d)(3)(v), Arizona must consider and
address the following seven factors within its LTS: (1) Emission
reductions due to ongoing air pollution control programs, including
measures to address RAVI; (2) measures to mitigate the impacts of
construction activities; (3) emissions limitations and schedules for
compliance to achieve the RPG; (4) source retirement and replacement
schedules; (5) smoke management techniques for agricultural and
forestry management purposes; (6) enforceability of emissions
limitations and control measures; and, (7) the anticipated net effect
on visibility due to projected changes in point, area, and mobile
source emissions over the period addressed by the LTS.
1. Ongoing Air Pollution Control Programs
    Arizona's LTS cites on-going air pollution control programs assumed
within the RHP as part of the 2002 base year inventory and projected
through 2018, such as Arizona's Vehicle Emissions Inspection Program
and federal diesel fuel standards for low diesel fuels; see the RHP at
pages 201-202. Mobile source emission reductions through 2018 are due
to ``on-the-books'' federal controls applied to on-road mobile sources
and non-road mobile sources and equipment; see chapter 11.4.4, page 173
for the list of assumed federal controls.
    The LTS also lists 10 PM10 nonattainment and maintenance
plan areas in Arizona; see page 202 of the RHP and Table 12.55. Arizona
asserts that the emission reduction programs in these areas provide
significant emission reduction benefits. Several fugitive dust rules
have been approved into the SIP and are cited as providing the emission
reductions within these areas: A.C.C. R18-2-602, A.C.C. R18-2-608,
Maricopa County Rule 310.01, and the Agricultural Best Practices
Program.\163\ The LTS does not describe ongoing state or local
stationary source emission reduction programs or regulations in detail;
however, the LTS mentions the New Source Review and the Prevention of
Significant Deterioration stationary source programs as they relate to
visibility impact assessment.\164\ Regarding specific stationary source
requirements, Arizona's BART reviews and determinations are discussed
elsewhere in the ARHP, such as Chapter 10 and Appendix D.
---------------------------------------------------------------------------

    \163\ These rules were approved into the Arizona SIP as follows:
R18-2-602 at 71 FR 28270, May 16, 2006; R18-2-608 at 47 FR 17485,
April 23, 1982 (renumbered from R18-2-408 and R9-3-408); Maricopa
County Rule 310.01, Fugitive Dust from Non-Traditional Sources of
Fugitive Dust, at 75 FR 78167, December 15, 2010; and, the
Agricultural Best Practices Program in R18-2-610 and R18-2-611 at 68
FR 51873, October 11, 2001.
    \164\ ARHP Chapter <IP_ADDRESS> at pages 198-199.
---------------------------------------------------------------------------

    The RHR also requires consideration of emission reductions due to
ongoing air pollution control programs such as those derived from the
Act's section 169A requirement for Arizona to reduce emissions from
sources determined to cause reasonably attributable visibility
impairment at Class I areas in the State (the RAVI program). Arizona
has no ongoing air pollution programs providing emission reductions due
to specific requirements of the RAVI program. In the late 1980s and
early 1990s, EPA implemented a FIP to address the requirements of
section 169A and EPA's RAVI rules.\165\ Ultimately, EPA found that
certain episodes of visibility impairment at the Grand Canyon National
Park were reasonably attributable to the Navajo Generating Station
(NGS) and required implementation of controls at NGS to reduce oxides
of sulfur emissions.\166\ Because NGS is located on the Navajo Indian
Reservation, Arizona has no ongoing responsibility for regulating this
source.
---------------------------------------------------------------------------

    \165\ See our rulemaking actions at: 52 FR 45134, (November 24,
1987); 53 FR 35956, (September 15, 1988); and, 56 FR 50172, (October
3, 1991) (codified at 40 CFR 52.145). Also, see the summary
discussion in the RHP at pages 199-200.
    \166\ 40 CFR 52.145(d).
---------------------------------------------------------------------------

    We propose to find that Arizona has met the requirement of 40 CFR
51.308(d)(3)(v)(A) to consider emission reductions due to ongoing air
pollution control programs, including measures to address RAVI.
2. Construction Activities
    The LTS cites Maricopa County Rules 300 and 310 as rules for
controlling fugitive dust emissions from construction activities.
Maricopa County Rule 310, Fugitive Dust from Dust Generating Operations
has been approved as a Best Available Control Measure-level rule for
serious PM10 nonattainment areas.\167\ Also, we approved
into the SIP Pinal County Rule 4-7, Construction Sites in Nonattainment
Areas--Fugitive Dust.\168\ Rule 300 has not been approved into the SIP.
---------------------------------------------------------------------------

    \167\ For the most recent SIP incorporated version of Rule 310,
see 75 FR 78167; (December 15, 2010).
    \168\ See 75 FR 17307; (April 6, 2010). Pinal County also
adopted and in this rulemaking we approved several other rules
related to controlling fugitive dust from unpaved roads and parking
areas.
---------------------------------------------------------------------------

    We propose to find that Arizona has met the requirement of 40 CFR
51.308(d)(3)(v)(B) to consider measures to mitigate the impacts of
construction activities.
3. Emissions Limitations and Schedules for Compliance
    The LTS states that, ``implementation of BART will contain emission
limits and schedules of compliance for those sources either installing
BART controls or taking federally enforceable permit limitations.''
\169\ However, as noted above, we have already disapproved the State's
BART determinations for NOX at

the following units: Apache Generating Station Units 2 and 3; Cholla
Generating Station Units 2, 3, and 4; Coronado Units 1 and 2.\170\ As
described in section VII of this document, we are also proposing to
disapprove certain elements of the state's BART determinations at other
sources. In addition, all of Arizona's BART determinations lack the
necessary compliance schedules and requirements for operation and
maintenance of control equipment and monitoring, recordkeeping and
reporting.
---------------------------------------------------------------------------

    \169\ ARHP section 12.7.3, page 203.
    \170\ See our proposed rule at 77 FR 42834, (July 20, 2012) and
our final rule at 77 FR 72512, (December 5, 2012) which addressed
these units.
---------------------------------------------------------------------------

    The LTS also states that Arizona ``did not identify any additional
measures that were appropriate for this first Regional Haze plan. As a
result, no other emission limitations or schedules of compliance are
included in this plan.'' \171\ As explained in section VIII above, we
are proposing to disapprove the State's reasonable progress analysis
and its conclusion that no additional emissions controls can be
reasonably implemented. Based on these shortcomings in the State's BART
and Reasonable Progress analyses, we do not believe that Arizona has
adequately considered the emission limits and schedules of compliance
necessary to achieve reasonable progress. Therefore, we propose to
determine that the ARHP does not meet the requirements of 40 CFR
51.308(d)(3)(v)(C).
---------------------------------------------------------------------------

    \171\ ARHP section 12.6.3, page 204.
---------------------------------------------------------------------------

4. Source Retirement and Replacement Schedules
    Chapter 12.7.4 of the LTS refers to an evaluation of sources to
provide a schedule of shutdowns, source retirements, and equipment
replacement in an earlier section of the LTS; however, no such
evaluation is found within Chapter 12.7.1.\172\ Appendix C of the ARHP
does, however, discuss the 2002 and 2018 emissions inventories
developed by the WRAP for Arizona; see pages 9--11 of Appendix C. The
base case 2018 projected emissions inventories developed by the WRAP
considered and accounted for source retirement and replacement for
point and area sources.\173\ These projections were updated in 2009 to
include new information about projected changes in electric demand and
the resultant impact on emissions from electric generating units.\174\
In a similar manner, the WRAP used EPA's MOBILE emissions model and
this model projected on-road mobile source fleet turnover and
replacement in Arizona over the 2002 to 2018 timeframe and these
emissions inventory estimates were incorporated in later visibility
modeling.
---------------------------------------------------------------------------

    \172\ See page 204 of the ARHP.
    \173\ See ``WRAP Point and Area Source Emissions Projection for
the 2018 Base Case Inventory'', Version 1, January 25, 2006 at
Chapters 4 and 5. Chapter 4 discusses projected growth to 2018,
including EGUs. Chapter 5 discusses point source retirement and
replacement rates used in the analysis. See: http://wrapair.org/forums/ssjf/documents/eictts/docs/WRAP_2018_EI-Version_1-Report_Jan2006.pdf.
    \174\ See ERG Technical Memorandum entitled ``WRAP PRP18b
Emissions Inventory--Revised Point and Area Source Projections'',
October 16, 2009.
---------------------------------------------------------------------------

    We propose to find that the ARHP meets the requirements of 40 CFR
51.308(d)(3)(v)(D) because it has considered adequately source
retirement and replacement.
5. Smoke Management Programs
    Arizona adopted rules consistent with a state certified smoke
management program. EPA has reviewed and approved the following rules
in the SIP: Rule R18-2-602, Unlawful Open Burning; Rule R18-2-1501,
Definitions; Rule R18-2-1502, Applicability; Rule R18-2-1503, Annual
Registration, Program Evaluation and Planning; Rule R18-2-1504,
Prescribed Burn Plan; Rule R18-2-1505, Prescribed Burn Requests and
Authorization; Rule R18-2-1506, Smoke Dispersion and Evaluation; Rule
R18-2-1507, Prescribed Burn Accomplishment, Wildfire Reporting; Rule
R18-2-1508, Wildland Fire Use: Plan, Authorization, Monitoring, Inter-
agency Consultation, Status Reporting; Rule R18-2-1509, Emission
Reduction Techniques; Rule R18-2-1510, Smoke Management Techniques;
Rule R18-2-1511, Monitoring; Rule R18-2-1512, Burner Qualifications;
and, Rule R18-2-1513, Public Notification Program, Regional
Coordination.\175\ Arizona believes these rules meet WRAP criteria for
an enhanced smoke management program; see Table 12.56, page 205 of the
RHP.
---------------------------------------------------------------------------

    \175\ See 71 FR 28270; (May 16, 2006).
---------------------------------------------------------------------------

    We propose to find that the ARHP meets the requirement of 40 CFR
51.308(d)(3)(v)(E) to consider smoke management techniques for
agricultural and forestry management purposes.
6. Enforceability of Measures in the Long-Term Strategy
    The RHR requires that the State consider the enforceability of
emissions limitations and control measures included in its plan, as
part of the LTS.\176\ Arizona has adopted and submitted, and EPA has
approved into the SIP many rules supporting the ARHP. Maricopa County
Rule 310 and the smoke management program rules listed above are
examples of the federally enforceable rules supporting the reasonable
progress goals of the ARHP.
---------------------------------------------------------------------------

    \176\ 40 CFR 51.308(d)(3)(v)(F).
---------------------------------------------------------------------------

    As noted earlier, however, we are have determined that Arizona's
BART determinations lack provisions to ensure their enforceability. In
our recent Phase 1 final rule, we found that the ARHP lacked the
necessary compliance deadlines and requirements for equipment
maintenance and operation, including monitoring, recordkeeping and
reporting requirements for all pollutants at all of the eight BART
units covered by that action.\177\ In today's action, we are proposing
to disapprove the lack of such ``enforceability requirements'' for
ADEQ's BART determinations at the two BART-subject copper smelters. As
explained above, we are also proposing to disapprove other elements of
the State's BART and reasonable progress analyses. Therefore, we
propose to determine that the ARHP does not meet the requirement of 40
CFR 51.308(d)(3)(v)(F).
---------------------------------------------------------------------------

    \177\ 77 FR 72512, (December 5, 2012).
---------------------------------------------------------------------------

7. Net Effect on Visibility Impairing Emissions Through 2018
    Pursuant to 40 CFR 51.308(d)(v)(F), the State must consider as part
of its LTS, the anticipated net effect on visibility due to projected
changes in point, area, and mobile source emissions over the period
addressed by the long-term strategy. Using WRAP-provided resources as
described in the ARHP, Arizona estimated the net effect on visibility
through 2018 due to changes in point, area, stationary and mobile
source emissions. Those visibility changes within each Class I area are
presented in detail in chapter 9.3 and are discussed in aggregate in
chapter 11 of the ARHP. In sum, 2018 visibility is projected to improve
in all Arizona Class I areas on the worst impaired days compared to
baseline conditions and 2018 visibility is projected to improve in all
but two Class I areas on the least impaired days compare to baseline
conditions. We, therefore, propose to determine that the ARHP meets the
requirement of 40 CFR 51.308(d)(3)(v)(G).

F. Summary of EPA's Evaluation of the LTS

    We propose to approve in part and disapprove in part the LTS
portion of the ARHP. Arizona has submitted an LTS addressing visibility
impairment due to regional haze within Class I areas, both inside and
outside of the

state. We review our proposed approvals and disapprovals below.
    Through participation in the WRAP, Arizona consulted with
neighboring states and coordinated the ARHP, as well as developed and
documented the technical basis for the ARHP. The State has estimated
the 2002 base year and 2018 emissions inventories and the emission
reductions resulting from the ARHP's control measures. The State
identified all anthropogenic sources of visibility impairment it
considered in developing the ARHP and LTS. The State has considered and
addressed measures to mitigate the impacts of construction activities
and to provide for smoke management from agricultural and forestry
practices. Through the WRAP and its analyses, Arizona considered and
estimated the net effect of the LTS on 2018 visibility levels.
Consequently, we propose to find that the LTS meets the requirements of
40 CFR 51.308(d)(3)(i), (iii), (iv), (v)(A), (v)(B), (v)(D), (v)(E),
and (v)(G) and we propose to approve the ARHP with respect to these
requirements.
    Because we have disapproved certain elements of the ARHP in our
Phase 1 final rule and are proposing to disapprove other elements
related to the implementation of enforceable BART controls and
enforceable controls for reasonable progress, we are also proposing to
determine that the LTS does not meet the requirements of 40 CFR
51.308(d)(3)(ii), (v)(C) and (v)(F). Therefore, we propose to find that
the LTS does not meet the requirements of 40 CFR 51.308(d)(3)(ii),
(v)(C), and (v)(F) and we propose to disapprove the ARHP with respect
to these requirements.

X. Monitoring Strategy and Other Requirements

A. Monitoring Strategy

    Arizona has elected to fulfill the requirements for a monitoring
strategy through participation in the IMPROVE network, as permitted
under the RHR.\178\ Arizona relies on the IMPROVE monitoring program to
collect and report data for reasonable progress tracking for all Class
I Areas in the state.\179\ Consequently, we propose to find that the
state has met the requirements of 40 CFR 51.308(d)(4) for a monitoring
strategy.
---------------------------------------------------------------------------

    \178\ 40 CFR 51.308(d)(4).
    \179\ ARHP, Chapter 4, ``Regional Haze Monitoring Network'', and
Section 12.7, pages 200-201.
---------------------------------------------------------------------------

B. State and Federal Land Manager Coordination

    Arizona participated fully in the WRAP, the primary forum for
consultation among western states, tribal nations, federal agencies,
stakeholder groups and the public. FLMs from the National Park Service
(NPS), U.S. Fish and Wildlife Service, Bureau of Land Management and
the U.S. Forest Service (USFS) were actively engaged in the WRAP's
development of technical analyses and reports that formed the basis of
Arizona's and other western state's regional haze plans. To facilitate
consultation as required in 51.308(i)(2), ADEQ provided a list of its
agency contacts to the FLMs followed by its draft RH SIP on September
20, 2010. Arizona ensured that the FLMs had an opportunity for
consultation in person and at least 60 days prior to the public hearing
that was held in Phoenix, Arizona, on December 2, 2010, which was also
the deadline for public comments. NPS submitted comments dated November
29 and December 1, 2010. The USFS submitted comments dated November 29,
2010. ADEQ responded to the FLMs' comments through its Responsiveness
Summary in Appendix E of the Arizona RH SIP. ADEQ outlined procedures
for continuing consultation with the FLMs in its RH SIP \180\ and
committed to provide the FLMs an opportunity to review and comment on
future SIP revisions, the 5-year progress reports, and the
implementation of other programs that may contribute to visibility
impairment in Arizona's Class I areas. EPA proposes to find that
Arizona has met the requirements for coordination with the FLMs under
40 CFR 51.308(i)(1-4).
---------------------------------------------------------------------------

    \180\ ARHP, Chapter 13, page 209.
---------------------------------------------------------------------------

C. Periodic SIP Revisions and 5-Year Progress Reports

    In the ARHP, Arizona affirmed its commitment to submit a
comprehensive SIP revision by July 31, 2018, and every ten years
thereafter as required in 40 CFR 51.308(f). In these comprehensive
revisions, the State must evaluate and reassess all of the elements
required in 40 CFR 51.308(d), taking into account improvements in
monitoring data collection and analysis techniques and control
technologies. The State must also address current visibility
conditions, actual progress toward natural conditions, effectiveness of
the long-term strategy, and the reasonable progress goals. Arizona also
confirmed it commitment to submit a report on reasonable progress every
five years that will evaluate progress toward meeting the RPGs for its
12 Class I area as well as Class I areas outside the State that may be
affected by emissions from within the State as required in 40 CFR
51.308(g). The first report is due five years after the State's
submittal, which is February 28, 2016.

XI. EPA's Evaluation of Arizona's Provisions for Interstate Transport
of Pollutants

    Section 110(a)(2)(D)(i)(II) requires that each SIP contain
``adequate provisions * * * prohibiting * * * any source or other types
of emission activity within the State from emitting any air pollutant
in amounts which will * * * interfere with measures required to be
included in the applicable implementation plan for any other State * *
* to protect visibility.'' EPA is proposing to find that Arizona's 2007
and 2009 Transport SIPs and Regional Haze Plan do not contain adequate
provisions to meet the ``good neighbor'' provisions of section
110(a)(2)(D)(i)(II) with respect to visibility for the 1997 8-hour
ozone, 1997 PM2.5, and 2006 PM2.5 NAAQS, nor a
demonstration that the existing Arizona SIP already includes measures
sufficient to meet the interstate transport visibility requirement.
    Our 2006 Guidance recommended that a state could meet the
visibility prong of the transport requirements for section
110(a)(2)(D)(i)(II) with an approved regional haze SIP.\181\ EPA's
reasoning was that the development of the regional haze SIPs was
intended to occur in a collaborative environment among the states, and
that through this process states would coordinate on emissions controls
to protect visibility on an interstate basis. In fact, in developing
their respective RPGs, WRAP states consulted with each other through
the WRAP's work groups. As a result of this process, the common
understanding was that each state would take action to achieve the
emissions reductions relied upon by other states in their reasonable
progress demonstrations under the RHR. Thus, we interpret the ``good
neighbor'' provisions of section 110(a)(2)(D)(i) as requiring states to
include in their SIPs either measures to prohibit emissions that would
interfere with the RPGs to protect visibility in Class I areas in other
states, or a demonstration that emissions from the state's sources and
activities will not have the prohibited impacts under the existing SIP.
This interpretation is consistent with the requirement of the RHR that
a state

participating in a regional planning process must include ``all
measures needed to achieve its apportionment of emission reduction
obligations agreed upon through that process.'' \182\
---------------------------------------------------------------------------

    \181\ ``Guidance for State Implementation Plan (SIP) Submissions
to Meet Current Outstanding Obligations Under Section
110(a)(2)(D)(i) for the [1997] 8-Hour Ozone and PM2.5
National Ambient Air Quality Standards'' (August 15, 2006); see also
``Guidance on SIP Elements Required Under Sections 110(a)(1) and (2)
for the 2006 24-hour Fine Particle (PM2.5) National
Ambient Air Quality Standards (NAAQS)'' (``2009 Guidance'').
    \182\ 40 CFR 51.308(d)(3)(ii).
---------------------------------------------------------------------------

    Since Arizona's 2007 and 2009 Transport SIPs did not specify which
parts of the State's regional haze program should be considered as
meeting the visibility requirement of section 110(a)(2)(D)(i)(II), we
considered the 2011 Regional Haze SIP as a whole in assessing whether
Arizona has met the visibility requirement of section
110(a)(2)(D)(i)(II). As discussed in sections VII (``EPA's Evaluation
of Arizona's BART Analyses and Determinations'') and VIII (``EPA's
Evaluation of Arizona's Reasonable Progress Goals'') of this proposed
rule, EPA is proposing to disapprove several aspects of Arizona's BART
and Reasonable Progress Analyses. Also, as previously noted, EPA has
already disapproved Arizona's determinations for NOX
emission limits at most of the units at Apache, Cholla, and
Coronado.\183\ The emissions from each of these sources affect
visibility in at least one Class I area in another state.\184\ The
proposed partial disapprovals in today's notice, if finalized, and the
final partial disapprovals for Apache, Cholla, and Coronado mean that
these portions of Arizona's Regional Haze Plan will not become part of
the Arizona SIP.
---------------------------------------------------------------------------

    \183\ 77 FR 42834 (July 20, 2012) (proposal), 77 FR 72512,
(December 5, 2012) (final).
    \184\ For example, Cholla Power Plant has been determined by
Arizona and EPA to affect visibility in Class I areas in Colorado,
New Mexico, and Utah. See 77 FR 42834 at 42861. Also, Arizona's RHP
discusses Arizona's contributions to visibility impairment in
Colorado, New Mexico, and Utah (see pages 179-181).
---------------------------------------------------------------------------

    Accordingly, Arizona's long-term strategy (i.e., the compilation of
all control measures that Arizona will implement to meet the relevant
RPGs) lacks enforceable emissions limitations for certain air
pollutants as necessary to achieve RPGs for all Class I areas affected
by emissions from Arizona, as required by 40 CFR 51.308(d)(3). As noted
above, we interpret the ``good neighbor'' provisions of section
110(a)(2)(D)(i) as requiring states to include in their SIPs either
measures to prohibit emissions that would interfere with the RPGs
required to be set to protect visibility in Class I areas in other
states or a demonstration that emissions from the state's sources and
activities will not have the prohibited impacts under the existing SIP.
Because we partially disapproved Arizona's BART provisions for three
sources (Apache, Cholla, and Coronado) and are proposing in this notice
to partially disapprove Arizona's BART and reasonable progress
analyses, we propose to conclude that the Arizona SIP does not include
sufficient measures to prohibit emissions that would interfere with the
RPGs for Class I areas in other states. Furthermore, Arizona has not
made a demonstration that emissions from the state's sources and
activities will not have the prohibited impacts under the existing SIP.
    Thus, we propose to find that Arizona's 2007 and 2009 Transport
SIPs and Regional Haze Plan do not contain adequate provisions to
prohibit emissions that interfere with SIP measures required of other
states to protect visibility.\185\ Accordingly, we propose to
disapprove these SIP revisions for the visibility requirement of
section 110(a)(2)(D)(i)(II) for the 1997 8-hour ozone, 1997
PM2.5, and 2006 PM2.5 NAAQS.
---------------------------------------------------------------------------

    \185\ As noted above, we previously acted on these submissions
with respect to the other three prongs. See 72 FR 41629 (July 31,
2007) and 77 FR 66398 (November 5, 2012). Therefore, today's action,
if finalized, will complete our action on these submissions.
---------------------------------------------------------------------------

XII. EPA's Proposed Action

A. Regional Haze

    EPA is proposing to approve in part and disapprove in part the
remaining portions of Arizona's RH SIP. Specifically, we are proposing
to approve the technical basis for the State's plan, most of the
analyses regarding which sources are eligible and which sources are
subject to BART, the BART determination for PM10 at the
Miami smelter and parts of the long-term strategy. We are proposing
alternatively to approve or disapprove the State's BART determination
for SO2 at the Hayden and Miami smelters, and whether the
Nelson Lime Plant is subject to BART.
    We are proposing to disapprove the State's BART determinations for
PM10 at the Hayden smelter and for NOX at the
Miami smelter as well as the State's finding that Unit 4 at Sundt is
not BART-eligible. In addition, we are proposing to disapprove the
visibility goals for the most and least impaired days, which set the
targets for evaluating progress. Moreover, we propose to disapprove
that part of the long-term strategy that requires enforceable emission
limits and compliance schedules that were not included in the SIP, and
were not adequately considered in setting the visibility goals. Our
consent decree deadline for taking final action on Arizona's RH SIP is
July 15, 2013.
    EPA is legally obligated to issue a FIP for the disapproved parts
of Arizona's RH SIP pursuant to CAA section 110(c)(1) and the court's
orders under the consent decree. Accordingly, we included a FIP in our
recently published final rule regarding three of Arizona's BART
sources. For today's proposed action on the SIP, we have a separate
court-ordered schedule for a FIP to address any disapproved elements of
the SIP. The consent decree deadlines for this FIP are to propose by
March 8, 2013, and take final action by October 15, 2013. Our
obligation to promulgate a FIP for those parts of the State's plan that
we are unable to approve is based on the State's failure to submit a
required SIP, and our subsequent failure to issue a FIP within two
years of our finding of failure to submit. EPA takes very seriously a
decision to disapprove all or part of a state plan. In this instance,
we believe that Arizona's SIP meets some, but not all of the RHR
requirements under the CAA. As a result, EPA considers that proposing
to disapprove portions of the State's plan is the only path that is
consistent with the Act at this time.

B. Interstate Transport of Visibility

    As discussed in section XI (``EPA's Evaluation of Arizona's
Provisions for Interstate Transport of Pollutants'') of this proposed
rule, EPA proposes to find that Arizona's 2007 and 2009 Transport SIPs
and Regional Haze Plan do not contain adequate provisions to prohibit
emissions that interfere with SIP measures required of other states to
protect visibility. Therefore, we propose to disapprove Arizona's 2007
and 2009 Transport SIPs and Regional Haze Plan for the visibility
requirement of section 110(a)(2)(D)(i)(II) for the 1997 8-hour ozone,
1997 PM2.5, and 2006 PM2.5 NAAQS.

C. Sanctions and FIP Duties

    Under section 179(a) of the CAA, final disapproval of a submittal
that addresses a requirement of part D, title I of the CAA (CAA
sections 171-193) or is required in response to a finding of
substantial inadequacy as described in CAA section 110(k)(5) (SIP Call)
starts a sanctions clock. Arizona's 2007 and 2009 Transport SIPs and
Regional Haze Plan were not submitted to meet either of these
requirements. Therefore, any action we take to finalize the described
partial disapproval will not trigger mandatory sanctions under CAA
section 179. In addition, CAA section 110(c)(1) provides that EPA must
promulgate a FIP within two years after finding that a State has failed
to make a required submission or disapproving a State

implementation plan submission in whole or in part, unless EPA approves
a SIP revision correcting the deficiencies within that two-year period.
Thus, our proposed disapproval of Arizona's 2009 Transport SIP with
respect to the visibility requirement of section 110(a)(2)(D)(i)(II)
for the 2006 PM2.5 NAAQS, if finalized, will establish a
deadline two years from the effective date of such final rule for EPA
to promulgate a FIP for this requirement, unless a SIP revision is
submitted by ADEQ and approved by EPA by that deadline.\186\ We
anticipate that any FIP designed to remedy the proposed disapprovals
described in this notice, if finalized, along with the already-
finalized partial BART FIP for Apache, Cholla, and Coronado, would also
remedy the disapproval, if finalized, for the interstate transport
visibility requirement of CAA section 110(a)(2)(D)(i)(II) for the 1997
8-hour ozone, 1997 PM2.5, and 2006 PM2.5 NAAQS.