Document ID: EPA-R08-OAR-2019-0177-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Colorado;  Regional Haze 5-Year Progress Report State Implementation Plan
Posted Date: 2019-07-17T04:00Z

[Federal Register Volume 84, Number 137 (Wednesday, July 17, 2019)]
[Proposed Rules]
[Pages 34083-34090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-15110]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2019-0177; FRL-9996-60-Region 8]

Approval and Promulgation of Implementation Plans; Colorado; 
Regional Haze 5-Year Progress Report State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) proposes to approve 
Colorado's regional haze progress report, submitted as a revision to 
its State Implementation Plan (SIP) by the Colorado Department of 
Public Health and Environment (CDPHE). Colorado's SIP revision 
addresses requirements of the Clean Air Act (CAA) and the EPA's rules 
that require states to submit periodic reports describing progress 
toward Reasonable Progress Goals (RPGs) established for regional haze 
and a determination of the adequacy of the state's existing plan 
addressing regional haze. Colorado's progress report explains that 
Colorado has implemented the measures in the regional haze plan due to 
be in place by the date of the progress report and that visibility in 
mandatory federal Class I areas affected by emissions from Colorado 
sources is improving. The EPA is proposing approval of Colorado's 
determination that the State's regional haze plan is adequate to meet 
RPGs for the first implementation period, which extended through 2018 
and requires no substantive revision at this time.

DATES: Written comments must be received on or before August 16, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2019-0177, to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
www.regulations.gov. The EPA may publish any comment received to its 
public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. The EPA will 
generally not consider comments or

[[Page 34084]]

comment contents located outside of the primary submission (i.e., on 
the web, cloud, or other file sharing system). For additional 
submission methods, the full EPA public comment policy, information 
about CBI or multimedia submissions, and general guidance on making 
effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Air and Radiation 
Division, Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop 
Street, Denver, Colorado 80202-1129. The EPA requests that if at all 
possible, you contact the individual listed in the FOR FURTHER 
INFORMATION CONTACT section to view the hard copy of the docket. You 
may view the hard copy of the docket Monday through Friday, 8:00 a.m. 
to 4:00 p.m., excluding federal holidays.

FOR FURTHER INFORMATION CONTACT: Kate Gregory, Air and Radiation 
Division, Environmental Protection Agency, Region 8, Mailcode 8ARD-QP, 
1595 Wynkoop Street, Denver, Colorado 80202-1129, (303) 312-6175, or by 
email at gregory.kate@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,'' 
``us,'' or ``our'' is used, we mean the EPA.

I. Background

    States are required to submit progress reports that evaluate 
progress towards the RPGs for each mandatory federal Class I area \1\ 
(Class I area) within the state and in each Class I area outside the 
state that may be affected by emissions from within the state. 40 CFR 
51.308(g). In addition, the provisions of 40 CFR 51.308(h) require 
states to submit, at the same time as the 40 CFR 51.308(g) progress 
report, a determination of the adequacy of the state's existing 
regional haze plan. The first progress report must take the form of a 
SIP revision and is due 5 years after submittal of the initial regional 
haze SIP. Colorado submitted the initial regional haze SIP on May 25, 
2011 and EPA approved the SIP on December 31, 2012.\2\
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    \1\ Areas designated as mandatory Class I federal areas consist 
of national parks exceeding 6000 acres, wilderness areas and 
national memorial parks exceeding 5000 acres, and all international 
parks that were in existence on August 7, 1977 (42 U.S.C. 7472(a)). 
isted at 40 CFR part 81, Subpart D.
    \2\ 77 FR 76871 (December 31, 2012), codified at 40 CFR 
52.320(c)(108)(i)(C) and 40 CFR 52.320(c)(124).
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    Twelve Class I areas are located in Colorado: Black Canyon of the 
Gunnison National Park, Eagles Nest Wilderness Area, Flat Tops 
Wilderness Area, Great Sand Dunes National Park, La Garita Wilderness 
Area, Maroon Bells-Snowmass Wilderness Area, Mesa Verde National Park, 
Mount Zirkle Wilderness Area, Rawah Wilderness Area, Rocky Mountain 
National Park, Weminuche Wilderness Area and West Elk Wilderness 
Area.\3\ Monitoring and data representing visibility conditions in 
Colorado's twelve Class I areas is based on the six Interagency 
Monitoring of Protected Visual Environments (IMPROVE) monitoring sites 
located across the state.\4\
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    \3\ Colorado Progress Report, p.4.
    \4\ Colorado Progress Report, p.6.
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    On May 2, 2016, Colorado submitted a progress report, which 
detailed the progress made in the first planning period toward 
implementation of the Long-Term Strategy (LTS) outlined in the 2012 
regional haze SIP, the visibility improvement measured at Class I areas 
affected by emissions from Colorado sources, and a determination of the 
adequacy of the State's existing regional haze plan. The State provided 
a public hearing for comment on the Progress Report on November 19, 
2015 and provided Federal Land Managers (FLMs) an opportunity to 
comment on the progress report.\5\ The EPA is proposing to approve 
Colorado's May 2, 2016 SIP submittal.
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    \5\ Colorado Progress Report, p.38, ``Public Comments NPS,'' 
``Public Comments USFS,'' Colorado's responses to those comments, 
and `Hearing Notice' available in docket.
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II. EPA's Evaluation of Colorado's Progress Report and Adequacy 
Determination

A. Regional Haze Progress Report

    This section describes the contents of Colorado's progress report 
and the EPA's analysis of the report, as well as an evaluation of the 
determination of adequacy required by 40 CFR 51.308(h) and the 
requirement for state and Federal Land Manager coordination in 40 CFR 
51.308(i).
1. Status of Implementation of Control Measures
    In its Progress Report, Colorado summarizes the emissions reduction 
measures that were relied upon by Colorado in the regional haze plan 
for ensuring reasonable progress at the Class I areas within the state. 
The State's regional haze SIP established RPGs for 2018 and established 
a LTS.6 7 In its Progress Report, the State describes 
Federal air pollution control programs, including; engine and auto 
pollution standards and NO2, SO2 and Ozone 
National Ambient Air Quality Standards (NAAQS).\8\ Additionally, 
Colorado describes State Regulation 9 as its smoke management 
program.\9\ Colorado also reviewed the status of Best Available 
Retrofit Technology (BART) requirements for the BART-eligible and 
Reasonable Progress (RP) sources in the state. The units subject to 
BART and RP are listed below in Table 1: Sources Subject to BART and 
Reasonable Progress in Colorado.
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    \6\ 77 FR 18090 (March 26, 2012). Table 43--Colorado's URP and 
RP Goal for 2018.
    \7\ 77 FR 76871 (December 31, 2012).
    \8\ Colorado Progress Report, p. 17.
    \9\ Colorado Progress Report, p. 19. As explained in the Report, 
Colorado's smoke management program for open burning and prescribed 
fire activities are state-only provisions.

                    Table 1--Sources Subject to BART and Reasonable Progress in Colorado \10\
----------------------------------------------------------------------------------------------------------------
                                              BART and Reasonable
    BART and Reasonable Progress (RP)         Progress (RP) source      BART or Reasonable Progress (RP) source
            eligible sources                        category
----------------------------------------------------------------------------------------------------------------
Clark Units 1 & 2.......................  EGU........................  RP
Cherokee Units 1, 2, & 3................  EGU........................  RP
Cherokee Unit 4.........................  EGU........................  BART
Arapahoe Units 3 & 4....................  EGU........................  RP
Valmont Unit 5..........................  EGU........................  BART
Pawnee Unit 1...........................  EGU........................  BART
Comanche Units 1 & 2....................  EGU........................  BART

[[Page 34085]]

 
Hayden Units 1 & 2......................  EGU........................  BART
Cameo Units 1 & 2.......................  EGU........................  RP
Craig Units 1 & 2.......................  EGU........................  BART
Craig Unit 3............................  EGU........................  RP
Nucla Unit 4............................  EGU........................  RP
Rawhide Unit 101........................  EGU........................  RP
Martin Drake Units 5, 6 & 7.............  EGU........................  BART
Nixon Unit 1............................  EGU........................  RP
Holcim Cement Plant.....................  Portland Cement Plant......  RP
Cemex Lyons Kiln and Dyer Cement Plant..  Portland Cement Plant......  BART
CENC Boiler 3...........................  EGU........................  RP
CENC Boilers 4 & 5......................  EGU........................  BART
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    In its Progress Report, Colorado provides the status of these BART 
and Reasonable Progress sources in the State. Table 2: Current Status 
of Colorado Sources Subject to BART and Reasonable Progress, shows 
emissions reductions from control types, including; selective catalytic 
reduction (SCR), low NOX burners (LNB), ultra-low 
NOX burners plus overfire air, selective non-catalytic 
reduction (SCNR), lime spray dryers, dry sorbent injection and wet lime 
scrubbers.\11\ As can be seen in Table 2, implementation of emission 
controls has resulted in NOX, SO2 and PM 
reductions during the time period listed (2006-2018).
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    \10\ 77 FR 76871, 76883 (December 31, 2012).
    \11\ Colorado Progress Report, p.16.

[[Page 34086]]

                                Table 2--Current Status of Colorado Sources Subject to BART and Reasonable Progress \12\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Nitrous Oxides (NOX)                  Sulfur Dioxides (SO2)                 Particulate Matter (PM)
                                    --------------------------------------------------------------------------------------------------------------------
                                      2006-2008                                                                     2006-2008
                                       Baseline       2015         2018      2006-2008       2015         2018       Baseline       2015         2018
                                      statewide    Statewide    Statewide     Baseline    Statewide    Statewide    statewide    Statewide    Statewide
                                         NOX          NOX          NOX       statewide       SO2          SO2           PM           PM           PM
                                      emissions    reductions   reductions      SO2       reductions   reductions   emissions    reductions   reductions
                                     (tons/year)  (tons/year)  (tons/year)   emissions   (tons/year)  (tons/year)  (tons/year)  (tons/year)  (tons/year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Clark Units 1 & 2..................          861          861          861        1,457        1,457        1,457           72           72           72
Cherokee Unit 1....................        1,556        1,556        1,556        2,221        2,221        2,221           37           37           37
Cherokee Unit 2....................        2,895        2,895        2,895        1,888        1,888        1,888           35           35           35
Cherokee Unit 3....................        1,866            0        1,866          743            0          743           65           65           65
Cherokee Unit 4....................        4,274            0        2,211        2,135            0        2,127           78           77           77
Arapahoe Unit 3....................        1,771        1,771        1,771          925          925          925          109          109          109
Arapahoe Unit 4....................        1,148        1,148        1,148        1,765        1,765        1,765           20           20           20
Valmont Unit 5.....................        2,314            0        2,314          758            0          758           42            0           42
Pawnee Unit 1......................        4,538        3,135        3,135       13,472       11,066       11,066          108            0            0
Comanche Unit 1....................        1,506            0            0        1,539            0            0           84            0            0
Comanche Unit 2....................        2,349            0            0        1,244            0            0           63            0            0
Hayden Unit 1......................        3,750        3,120        3,120        1,172           61           61           96            0            0
Hayden Unit 2......................        3,473            0        3,032        1,469           39           39          119            0            0
Cameo Units 1 & 2..................        1,140        1,140        1,140        2,618        2,618        2,618          225          225          225
Craig Unit 1.......................        5,190            0            0          970            0            0          100            0            0
Craig Unit 2.......................        5,372            0        3,975          982            0            0           87            0            0
Craig Unit 3.......................        5,693            0          854        1,792            0            0           70            0            0
Nucla Unit 4.......................        1,675            0            0        1,335            0            0           55            0            0
Rawhide Unit 101...................        1,866          448          448          913            0            0          117            0            0
Drake Unit 5.......................          768            0          215        1,269            0          762           27            0            0
Drake Unit 6.......................        1,413          509          509        2,785            0        2,368           58            0            0
Drake Unit 7.......................        2,081          749          749        4,429            0        3,764           55            0            0
Nixon Unit 1.......................        2,357            0          707        4,121            0        3,215           87            0            0
Holcim Unit 1......................        3,186            0        1,099          287            0            0           58            0            0
Cemex Cement.......................        1,747            0          846           95            0            0           10            0            0
CENC Boiler 3......................          180          -66          -66          257            0            0            2            0            0
CENC Boiler 4......................          599          214          214          780            0            0           11            0            0
CENC Boiler 5......................          691          354          354        1,406            0            0           18            0            0
                                    --------------------------------------------------------------------------------------------------------------------
    Total Emissions Reductions            66,528       17,833       34,952       54,828       22,040       35,777        1,908          640          682
     (tons/year)...................
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[[Page 34087]]

    EPA also approved provisions in Colorado's regional haze SIP 
covering certain existing internal combustion engines (RICE) reasonable 
progress sources. These provisions control ozone via ozone precursors 
(volatile organic compounds (VOCs) and NOX) from certain 
existing RICE,\13\ and therefore, the State's Report includes 
information about emission reductions from these types of sources. \14\
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    \12\ Colorado Progress Report, p.16.
    \13\ 77 FR 76871, 76883 (December 31, 2012).
    \14\ Colorado Progress Report, p.19.
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    EPA proposes to find that Colorado has adequately addressed the 
applicable provisions under 40 CFR 51.308(g) regarding the 
implementation status of control measures because the State's Progress 
Report provides documentation of the implementation of measures within 
Colorado, including the BART-eligible sources and RP sources in the 
State.
2. Summary of Emissions Reductions
    In its Progress Report, Colorado presents information on emissions 
reductions achieved across the State from the pollution control 
strategies discussed above. The Progress Report includes statewide 
SO2, NOX, VOCs and PM (fine and coarse) emissions 
data from Western Regional Air Partnership (WRAP) emissions 
inventories.15 16 The Progress Report includes emissions 
inventories the 2002 WRAP (Plan02d) and the 2008 WRAP (WestJump2008c) 
as baseline data and the 2011 WRAP (WAQDW 2011v1) as updated data from 
the baseline.\17\ The emissions data shows that there were decreases in 
emissions of SO2 and NOX over the time period 
(i.e., 2002 and 2011).
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    \15\ Colorado Progress Report, Tables 4a to 4h, pp. 22 to 29. 
Colorado, as other states, relies on the WRAP emissions inventories 
for examination of visibility changes. CO used WRAP regional summary 
reports for the period 2011-2013 to compare to baseline emissions 
data (2000-2004). The WRAP's inventories were developed using EPA's 
National Emissions Inventory (NEI) and other sources (https://www.wrapair2.org/emissions.aspx). The NEI is based primarily upon 
data provided by state, local, and tribal air agencies (including 
Colorado) for sources in their jurisdiction and supplemented by data 
developed by the EPA.
    \16\ The State included emissions data on VOCs, Ammonia and 
Elemental Carbon.
    \17\ Colorado Progress Report, pp. 22, 23, 26, 27.
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    In its Progress Report, Colorado provides information that shows 
emissions from NOX and SO2 have decreased over 
the time period listed (2002-2011).\18\ The State cites regional haze 
and mobile source controls for being effective at reducing 
NOX and SO2.\19\ The State provides data that 
shows both coarse and fine particulate matter increasing over the time 
period listed (2002-2011).\20\ In its Progress Report, Colorado 
explains that both `coarse and fine particulate matter are dominated by 
fugitive and windblown dust' and presents data to show that fugitive 
and wind-blown dust are source categories that most impact coarse and 
fine PM.\21\ The State explains the origins of the increase in fugitive 
road dust seen in Figures 5b and 5c are unclear.\22\ Additionally, the 
State presents data to show that VOC emissions decreased in the time 
period 2002-2008 and increased in the time period 2008-2011.\23\
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    \18\ Colorado Progress Report, pp. 22 & 23.
    \19\ Ibid.
    \20\ Colorado Progress Report, pp. 26 & 27.
    \21\ Colorado Progress Report, p. 26.
    \22\ Colorado Progress Report, pp. 26 & 31.
    \23\ Colorado Progress Report, p. 23.
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    The EPA proposes to find that Colorado has adequately addressed the 
applicable provisions of 40 CFR 51.308(g) regarding emissions 
reductions achieved because the State identifies emissions reductions 
for SO2 and NOX. Additionally, Colorado presents 
sufficient emission inventory information and discussion regarding 
emissions trends for coarse and fine PM during the 2002-2011 time 
period.
3. Visibility Conditions and Changes
    In its Progress Report, Colorado provides information on visibility 
conditions for the Class I areas within its borders. The Progress 
Report addressed current visibility conditions and the difference 
between current visibility conditions and baseline visibility 
conditions, expressed in terms of 5-year rolling averages of these 
annual values, with values for the most impaired (20% worst days), 
least impaired and/or clearest days (20% best days). The period for 
calculating current visibility conditions is the most recent 5-year 
period preceding the required date of the progress report for which 
data were available as of a date 6 months preceding the required date 
of the progress report.
    Colorado's Progress Report provides figures with visibility 
monitoring data for the twelve Class I areas within the State. Colorado 
reported current visibility conditions for the 2009-2013 5-year time 
period and used the 2000-2004 baseline period for its examination of 
visibility conditions and changes in the State.\24\ In its Progress 
Report, Colorado presents visibility data, in deciviews, and 
representative IMPROVE monitors for Class I areas without an IMPROVE 
monitor, as there are not IMPROVE monitors in each of Colorado's twelve 
Class I areas. Table 3: Colorado's Class I areas and IMPROVE Sites, 
below, shows the IMPROVE monitors used for each Class I area.\25\
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    \24\ For the first regional haze plans, ``baseline'' conditions 
were represented by the 2000-2004 time period. See 64 FR 35730 (July 
1, 1999).
    \25\ Colorado Progress Report, p.6.

           Table 3--Colorado's Class I Areas and IMPROVE Sites
------------------------------------------------------------------------
              Class I area                         IMPROVE site
------------------------------------------------------------------------
Great Sand Dunes National Park..........  GRSA1
Mesa Verde National Park................  MEVE1
Mount Zirkle Wilderness Area............  MOZI1
Rawah Wilderness Area...................  MOZI1
Rocky Mountain National Park............  ROMO1
Weminuche Wilderness Area...............  WEMI1
Black Canyon of the Gunnison National     WEMI1
 Park.
La Garita Wilderness Area...............  WEMI1
Eagle's Nest Wilderness Area............  WHRI1
Flat Tops Wilderness Area...............  WHRI1
Maroon Bells-Snowmass Wilderness Area...  WHRI1
West Elk Wilderness Area................  WHRI1
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    Table 4: Visibility Progress in Colorado's Class I Areas, below, 
shows the difference between the current visibility conditions 
(represented by 2009-2013 data), baseline visibility conditions 
(represented by 2000-2004 data) and the 2018 RPGs.

[[Page 34088]]

                          Table 4--Visibility Progress in Colorado's Class I Areas \26\
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                                                                     Baseline      Difference in
                                                  Current period      period      deciviews (dv)
    Colorado's class I area       IMPROVE site    deciviews 2009- deciviews 2000-    Current-       CO 2018 RPG
                                                     2013 (dv)       2004 (dv)       baseline
----------------------------------------------------------------------------------------------------------------
                          20% Worst Days 27 [20% Most Anthropogenically Impaired Days]
----------------------------------------------------------------------------------------------------------------
Great Sand Dunes National Park  GRSA1...........           11.56           12.80           -1.24           12.20
Mesa Verde National Park......  MEVE1...........           11.24           13.00           -1.76           12.50
Mount Zirkle Wilderness Area..  MOZI1...........            9.12           10.50           -1.38            9.91
Rawah Wilderness Area.........  MOZI1...........            9.12           10.50           -1.38            9.91
Rocky Mountain National Park..  ROMO1...........           11.84           13.80           -1.96           12.83
Weminuche Wilderness Area.....  WEMI1...........            9.88           10.30           -0.42            9.83
Black Canyon of the Gunnison    WEMI1...........            9.88           10.30           -0.42            9.83
 National Park.
La Garita Wilderness Area.....  WEMI1...........            9.88           10.30           -0.42            9.83
Eagle's Nest Wilderness Area..  WHRI1...........            8.48            9.60           -1.12            8.98
Flat Tops Wilderness Area.....  WHRI1...........            8.48            9.60           -1.12            8.98
Maroon Bells--Snowmass          WHRI1...........            8.48            9.60           -1.12            8.98
 Wilderness Area.
West Elk Wilderness Area......  WHRI1...........            8.48            9.60           -1.12            8.98
----------------------------------------------------------------------------------------------------------------
                                                20% Best Days 28
----------------------------------------------------------------------------------------------------------------
Great Sand Dunes National Park  GRSA1...........            3.80            4.50           -0.70            4.16
Mesa Verde National Park......  MEVE1...........            3.00            4.32           -1.32            4.10
Mount Zirkle Wilderness Area..  MOZI1...........            0.46            1.60           -1.55            1.29
Rawah Wilderness Area.........  MOZI1...........            0.46            1.60           -1.55            1.29
Rocky Mountain National Park..  ROMO1...........            1.58            2.28           -0.70            2.06
Weminuche Wilderness Area.....  WEMI1...........            2.06            3.10           -1.04            2.93
Black Canyon of the Gunnison    WEMI1...........            2.06            3.10           -1.04            2.93
 National Park.
La Garita Wilderness Area.....  WEMI1...........            2.06            3.10           -1.04            2.93
Eagle's Nest Wilderness Area..  WHRI1...........      \29\ -0.10            0.73           -0.83            0.53
Flat Tops Wilderness Area.....  WHRI1...........           -0.10            0.73           -0.83            0.53
Maroon Bells--Snowmass          WHRI1...........           -0.10            0.73           -0.83            0.53
 Wilderness Area.
West Elk Wilderness Area......  WHRI1...........           -0.10            0.73           -0.83            0.53
----------------------------------------------------------------------------------------------------------------

    As shown in Table 4, all IMPROVE monitoring sites within the State 
show improvement in visibility conditions on the 20% best days and are 
meeting the 2018 20% best days RPGs.\30\ Additionally, five of the six 
IMPROVE monitors show visibility better than the 2018 20% worst days 
RPGs.\31\ The IMPROVE site that does not show visibility data meeting 
the 2018 20% worst days RPGs, Weminuche (WEMI1), that represents three 
class one areas in the state, shows progress from the baseline period 
provided (2002-2004), however, for the years 2009 through 2013, 
visibility falls short of the 2018 RPG by only 0.05 dv.\32\
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    \26\ Colorado Progress Report, p. 8.
    \27\ Colorado Progress Report, p. 6.
    \28\ Ibid.
    \29\ While counterintuitive, deciview values are sometimes 
negative and represent pristine visibility conditions.
    \30\ Colorado Progress Report, p. 8.
    \31\ Ibid.
    \32\ Colorado Progress Report, p.10.
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    Additionally, in its Progress Report, Colorado describes visibility 
in the state being significantly impacted by anthropogenic emissions 
from within the state and regional `blowing dust, wildfires, and 
transport of pollutants into Colorado from international emissions and 
other western states, much of which is not controllable by state 
measures.' \33\
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    \33\ Colorado Progress Report, p.10.
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    The EPA proposes to find that Colorado has adequately addressed the 
applicable provisions under 40 CFR 51.308(g) regarding assessment of 
visibility conditions because the State provided baseline visibility 
conditions (2002-2004), more current conditions based on the most 
recently available visibility monitoring data available at the time of 
Progress Report development (2011-2015), the difference between these 
current sets of visibility conditions and baseline visibility 
conditions, and the change in visibility impairment from 2000-2015 at 
the Class I areas.
4. Emissions Tracking
    In its Progress Report, Colorado presents data from the statewide 
emissions inventory for 2008 (WestJump 2008c) and 2011 (WAQDW 2011v1) 
and compares this data to the baseline emissions inventory for 2002 
(Plan02d). The pollutants inventoried include SO2, 
NOX, VOCs and PM (fine and coarse). The emissions 
inventories include the following type of source or activity 
classifications: Point; area; on-road mobile; off-road mobile; point 
and WRAP area (including oil and gas); fugitive and road dust; 
anthropogenic fire; natural fire; biogenic and wind-blown dust from 
both anthropogenic and natural sources. Table 5 presents the 2002 
baseline, and the 2008 and 2011 more current data. As can be seen in 
Table 5, statewide emissions of both SO2 and NOX 
are lower than the projected 2018 emissions, while statewide emissions 
for both coarse and fine PM have increased in the time period shown. As 
is discussed above in section 2, Colorado explains that both coarse and 
fine PM are dominated by fugitive and windblown dust and presents data 
to show that fugitive and wind-blown dust are source categories that 
most impact coarse and fine PM and that the origins are unclear to the 
State.\34\ VOCs decreased between the years 2002 and 2008 and increased 
between the years 2008 and 2011.
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    \34\ Colorado Progress Report, p. 26.

[[Page 34089]]

                                  Table 5--Emissions Progress in Colorado \35\
----------------------------------------------------------------------------------------------------------------
                                    SO2 (tons/      NOX (tons/       PM Coarse    PM Fine (tons/    VOCs (tons/
                                       year)           year)        (tons/year)        year)           year)
----------------------------------------------------------------------------------------------------------------
2002 Total Emissions (Plan02d)..         114,636         404,465         222,546          34,681       1,181,756
2008 Total Emissions (WestJump            68,118         329,727         258,365          43,613         612,318
 2008c).........................
2011 Total Emissions (WAQDW               54,021         273,905         354,084          57,571         735,121
 2011v1)........................
Change 2002-2008 (%)............            -40%            -18%              1%             25%            -48%
Change 2008-2011 (%)............            -52%            -32%             37%             32%             20%
----------------------------------------------------------------------------------------------------------------

    The EPA is proposing to find that Colorado adequately addressed the 
applicable provisions of 40 CFR 51.308(g) regarding emissions tracking 
because the State compared the most recent updated emission inventory 
data available at the time of Progress Report development with the 
baseline emissions inventory used in the modeling for the regional haze 
plan.
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    \35\ Colorado Progress Report, Tables 4a, 4b, 4c, 4e & 4f, pp. 
22 to 27.
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5. Assessment of Changes Impeding Visibility Progress
    In its Progress Report, Colorado provided an assessment of any 
significant changes in anthropogenic emissions within or outside the 
State that have occurred. The State cites wildfire as a major factor in 
visibility changes in the State.\36\ In its Progress Report, Colorado 
explains that the state is downwind of wildfire prone areas and is also 
adjacent to states that have wildfire impacting visibility in 
Colorado.\37\ Colorado has a prescribed fire burn program (Regulation 
9) that tracks emissions from coarse and fine PM resulting from these 
burns.\38\ In its Progress Report, the State provides discussion on 
data from the National Interagency Fire Center, which tracks wild land 
and prescribed burns. This data shows that while the acres burned for 
prescribed fires remain relatively constant, there is significant 
variability in wild land fire acres burned from year to year.\39\ As 
the data show, natural variability in fires continues to pose 
challenges for the State in evaluating the impacts of anthropogenic 
emissions on Regional Haze.\40\
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    \36\ Colorado Progress Report, p. 34.
    \37\ Ibid.
    \38\ Colorado's Progress Report indicates that it ``maintains an 
EPA-approved prescribed burn program (Regulation 9)''. Colorado 
Progress Report, p. 34. As this statement conflicts with other 
statements in the Report, EPA sought clarification from the State 
and learned that that statement was inadvertently includes in the 
report. Email from Curtis Taipale, State Implementation Plan--
Technical Development Unit Supervisor Planning and Policy Program, 
Colorado Department of Health & the Environment, to Kate Gregory, 
``Request for Regional Haze Contact.'' June 18, 2019.
    \39\ Ibid.
    \40\ Colorado Progress Report, p. 34, and Figure 9 (p. 35) and 
Tables 4a-4h (pp. 22-29).
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    The EPA proposes to find that Colorado has adequately addressed the 
applicable provisions of 40 CFR 51.308(g) regarding an assessment of 
significant changes in anthropogenic emissions. The EPA proposes to 
agree with Colorado's conclusion that wild fire (both inside and 
outside Colorado) and regional dust storms will likely impede future 
progress towards Regional Progress Goals.
6. Assessment of Current Implementation Plan Elements and Strategies
    In its Progress Report, Colorado acknowledges the requirements of 
40 CFR 51.308(g) to assess whether the current implementation plan 
elements and strategies are sufficient to enable the State, or other 
states with Class I areas affected by emissions from the State, to meet 
all established reasonable progress goals. In its Progress Report, 
Colorado explains the State had previous emissions modeling that showed 
impacts to visibility in a Class I Area in New Mexico, (WPHE1 IMPROVE 
monitor).\41\ Colorado explains it exceeded the emission reduction 
goals in the 2011 RH SIP and that it can be reasonably expected that 
effects on the monitor where past modeling showed Colorado had this 
small impact are declining as a result of the RH controls in 
Colorado.42 43
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    \41\ Colorado Progress Report, p. 2.
    \42\ Colorado Progress Report, p. 2. Additionally, in approving 
Colorado's RH SIP, EPA determined that Colorado satisfied the RHR's 
requirements for consultation and included controls in the SIP 
sufficient to address the relevant requirements of the RHR related 
to impacts on Class I areas in other states. 77 FR 18052, 18094 
(March 26, 2012). 77 FR 76871 (December 31, 2012).
    \43\ We provide the following to clarify statements made on page 
37 of the State's Report. The State references its March 2010 
Interstate Transport SIP submittal, where the State elected to 
satisfy one of the Interstate Transport requirements by providing 
information to show that it does not interfere with other State's 
measures to protect visibility through their RH SIP. 76 FR 8326, 
8328 (February 14, 2011) (EPA proposed approval of Interstate 
Transport of Pollution Revisions for the 1997 8-Hour Ozone and 1997 
PM2.5 NAAQS); 76 FR 22036 (April 20, 2011) (EPA final 
action). In that action, EPA supplemented the State's Interstate 
Transport analysis and focused on the most impacted Class I area 
(Canyonlands)--rather than the IMPROVE monitor for the Wheeler Peak 
and Pecos Wildernesses mentioned in Colorado's Progress Report--and 
found that Colorado does not interfere with another States' measures 
to protect visibility in their RH SIP. 76 FR 8329.
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    As seen in Table 4, visibility conditions have improved in the 
State at all IMPROVE monitoring sites and the State is meeting its RPGs 
in all Class I areas on the 20% best days. Additionally, five of the 
six IMPROVE sites meet the 2018 RPGs established for the state.\44\
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    \44\ Colorado Progress Report, p. 36.
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    The IMPROVE monitoring site with visibility not meeting the 2018 
RPG, Weminuche (WEMI1), does show improvement despite significant 
wildfire events in the state during this planning period.\45\ Looking 
in more detail at the data from this and other monitors, the State 
observed the following: Clear reductions in organic, sulfate, and 
nitrate fractions; slight increases in coarse mass and soil fractions; 
and the least amount of variability.\46\ Colorado describes regional 
dust events, wildfire and interstate pollution as impacting this site, 
all of which are not reasonably controllable by statewide emission 
control measures.\47\ Nevertheless, Colorado explains it will continue 
to monitor these concerns and evaluate possible additional controls on 
anthropogenic emissions impacting this site.\48\ Therefore, Colorado 
believes that at this time this site is most impacted by natural 
variability in regional wind-blown dust and does not specifically 
recommend further analysis at this time.\49\
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    \45\ Ibid.
    \46\ Colorado Progress Report, p. 36.
    \47\ Ibid.
    \48\ Ibid.
    \49\ Colorado Progress Report, p. 36.
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    The EPA proposes to find that Colorado has adequately addressed the 
applicable provisions of 40 CFR 51.308(g) and agrees with the State's 
determination that its regional haze plan is sufficient to meet the 
RPGs for its Class I areas.

[[Page 34090]]

7. Review of Current Monitoring Strategy
    For progress reports for the first implementation period, the 
provisions under 40 CFR 51.308(g) require a review of the State's 
visibility monitoring strategy and any modifications to the strategy as 
necessary. In its Progress Report, Colorado summarizes the existing 
monitoring network in the State to monitor visibility at the twelve 
Class I areas within the State, which consists of Colorado relying on 
the national IMPROVE network to meet monitoring and data collection 
goals. There are currently six IMPROVE sites, which the State explains, 
continue to provide adequate and complete data records.\50\ In the 
Progress Report, the State finds that the current monitoring network is 
sufficient at this time to monitor progress towards RPGs.\51\ The 
IMPROVE monitoring network is the primary monitoring network for 
regional haze, both nationwide and in Colorado.
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    \50\ Colorado Progress Report, p. 6.
    \51\ Colorado Progress Report, p. 37.
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    The EPA proposes to find that Colorado has adequately addressed the 
applicable provisions of 40 CFR 51.308(g) regarding a monitoring 
strategy because the State reviewed its visibility monitoring strategy 
and determined that no further modifications to the strategy are 
necessary.

B. Determination of Adequacy of the Existing Regional Haze Plan

    The provisions under 40 CFR 51.308(h) require states to determine 
the adequacy of their existing implementation plan to meet existing 
goals. Colorado's Progress Report includes a negative declaration 
regarding the need for additional actions or emissions reductions in 
Colorado beyond those already in place and those to be implemented by 
2018 according to Colorado's SIP.52 53
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    \52\ Colorado Progress Report, p. 38.
    \53\ Additionally, Colorado's Report explains that the State 
``actively participates in maintenance of commitments associated 
with RH plan requirements'' and continues ``to work collaboratively 
with the scientific research community to refine our understanding 
of air quality issues in Colorado.'' Colorado Progress Report, p. 
38.
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    The EPA proposes to conclude that Colorado has adequately addressed 
40 CFR 51.308(h) because the visibility trends in the majority of Class 
I areas in the State indicate that the relevant RPGs will be met via 
emission reductions already in place and therefore the SIP does not 
require substantiative revisions at this time to meet those RPGs.

III. Proposed Action

    The EPA is proposing to approve Colorado's May 2, 2016, Regional 
Haze Progress Report as meeting the applicable regional haze 
requirements set forth in 40 CFR 51.308(g) and 51.308(h).

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely proposes to approve state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory action because SIP approvals are exempted under 
Executive Order 12866;
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the proposed rule does not have tribal implications and will 
not impose substantial direct costs on tribal governments or preempt 
tribal law as specified by Executive Order 13175 (65 FR 67249, November 
9, 2000).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Greenhouse 
gases, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting and 
recordkeeping requirements, Sulfur oxides, Volatile organic compounds.

    Authority:  42 U.S.C. 7401 et seq.

    Dated: July 11, 2019.
Gregory Sopkin,
Regional Administrator, EPA Region 8.
[FR Doc. 2019-15110 Filed 7-16-19; 8:45 am]
 BILLING CODE 6560-50-P