[Federal Register Volume 86, Number 117 (Tuesday, June 22, 2021)]
[Proposed Rules]
[Pages 32656-32669]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-12875]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2021-0262; FRL-10025-02-Region 8]


Approval and Promulgation of Implementation Plans; Colorado; 
Revisions to Regulation Number 7; Aerospace, Oil and Gas, and Other 
RACT Requirements for 2008 8-Hour Ozone Standard for the Denver Metro/
North Front Range Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing 
approval of State Implementation Plan (SIP) revisions submitted by the 
State of Colorado on May 14, 2018, May 8, 2019, and May 13, 2020. The 
revisions are to Colorado Air Quality Control Commission (Commission or 
AQCC) Regulation Number 7 (Reg. 7). The revisions to Reg. 7 address 
Colorado's SIP obligation to require reasonably available control 
technology (RACT) for sources covered by the 2016 oil & natural gas 
control techniques guidelines (CTG or CTGs) for Moderate nonattainment 
areas under the 2008 ozone National Ambient Air Quality Standard 
(NAAQS); update RACT requirements for major sources of volatile organic 
compounds (VOC) and nitrogen oxides (NO<INF>x</INF>); reorganize the 
regulation; add incorporation by reference dates to rules and reference

[[Page 32657]]

methods; and make typographical, grammatical, and formatting 
corrections. Also, the EPA is proposing to finalize approval of the 
State's negative declaration that there are no sources in the Denver 
Metro/North Front Range (DMNFR) Area subject to the aerospace CTG, 
which was conditionally approved in our February 24, 2021 rulemaking. 
The EPA is taking this action pursuant to the Clean Air Act (CAA).

DATES: Written comments must be received on or before July 22, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2021-0262, 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 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 electronically in 
www.regulations.gov. To reduce the risk of COVID-19 transmission, for 
this action we do not plan to offer hard copy review of the docket. 
Please email or call the person listed in the FOR FURTHER INFORMATION 
CONTACT section if you need to make alternative arrangements for access 
to the docket.

FOR FURTHER INFORMATION CONTACT: Abby Fulton, Air and Radiation 
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, 
Colorado 80202-1129, (303) 312-6563, <a href="/cdn-cgi/l/email-protection#f294879e869d9cdc9390908bb2978293dc959d84"><span class="__cf_email__" data-cfemail="d0b6a5bca4bfbefeb1b2b2a990b5a0b1feb7bfa6">[email protected]</span></a>.

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

I. What action is the EPA taking?

    As explained below, the EPA is proposing to approve various 
revisions to the Colorado SIP that were submitted to the EPA on May 14, 
2018, May 8, 2019, May 13, 2020, and March 22, 2021. In particular, we 
propose to approve certain Reg. 7 rules to meet the 2008 8-hour ozone 
NAAQS oil and gas CTG RACT requirements for Moderate nonattainment 
areas that were not acted on in our July 3, 2018 \1\ and February 24, 
2021 \2\ rulemakings. We are also proposing to approve certain area 
source rules as meeting the 2008 8-hour ozone NAAQS RACT requirements 
for Serious nonattainment areas. Additionally, we are proposing to 
finalize approval of the State's negative declaration that there are no 
sources in the DMNFR Area subject to the aerospace CTG, which was 
conditionally approved in our February 24, 2021 \3\ rulemaking.
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    \1\ Final Rule, Approval and Promulgation of State 
Implementation Plan Revisions; Colorado; Attainment Demonstration 
for the 2008 8-Hour Ozone Standard for the Denver Metro/North Front 
Range Nonattainment Area, and Approval of Related Revisions, 83 FR 
31068, 31069-31072.
    \2\ Final Rule, Approval and Promulgation of Implementation 
Plans; Colorado; Revisions to Regulation Number 7 and RACT 
Requirements for 2008 8-Hour Ozone Standard for the Denver Metro/
North Front Range Nonattainment Area, 86 FR 11125, 11126 -11127.
    \3\ 86 FR 11125.
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    The specific bases for our proposed actions, our analyses, and 
proposed findings are discussed in this proposed rulemaking. Technical 
information that we are relying on is in the docket, available at 
http://www.regulations.gov, Docket No. EPA-R08-OAR-2021-0262.

II. Background

2008 8-Hour Ozone NAAQS Nonattainment

    On March 12, 2008, the EPA revised both the primary and secondary 
NAAQS for ozone to a level of 0.075 parts per million (ppm) (based on 
the annual fourth-highest daily maximum 8-hour average concentration, 
averaged over 3 years), to provide increased protection of public 
health and the environment.\4\ The 2008 ozone NAAQS retains the same 
general form and averaging time as the 0.08 ppm NAAQS set in 1997, but 
is set at a more protective level. Specifically, the 2008 8-hour ozone 
NAAQS is attained when the 3-year average of the annual fourth-highest 
daily maximum 8-hour average ambient air quality ozone concentrations 
is less than or equal to 0.075 ppm.\5\
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    \4\ Final rule, National Ambient Air Quality Standards for 
Ozone, 73 FR 16436 (March 27, 2008). The EPA has since further 
strengthened the ozone NAAQS, but the 2008 8-hour standard remains 
in effect. See Final Rule, National Ambient Air Quality Standards 
for Ozone, 80 FR 65292 (Oct. 26, 2015).
    \5\ 40 CFR 50.15(b).
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    Effective July 20, 2012, the EPA designated as nonattainment any 
area that was violating the 2008 8-hour ozone NAAQS based on the three 
most recent years (2008-2010) of air monitoring data.\6\ With that 
rulemaking, the Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado 
area (Denver or DMNFR Area) area was designated nonattainment and 
classified as Marginal.\7\ Ozone nonattainment areas are classified 
based on the severity of their ozone levels, as determined using the 
area's design value. The design value is the 3-year average of the 
annual fourth highest daily maximum 8-hour average ozone concentration 
at a monitoring site.\8\ Areas that were designated as Marginal 
nonattainment were required to attain the 2008 8-hour ozone NAAQS no 
later than July 20, 2015, based on 2012-2014 monitoring data.\9\
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    \6\ Final rule, Air Quality Designations for the 2008 Ozone 
National Ambient Air Quality Standards, 77 FR 30088 (May 21, 2012).
    \7\ Id. at 30110. The nonattainment area includes Adams, 
Arapahoe, Boulder, Broomfield, Denver, Douglas and Jefferson 
Counties, and portions of Larimer and Weld Counties. See 40 CFR 
81.306.
    \8\ 40 CFR part 50, appendix I.
    \9\ See 40 CFR 51.903.
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    On May 4, 2016, the EPA published its determination that the Denver 
Area, among other areas, had failed to attain the 2008 8-hour ozone 
NAAQS by the attainment deadline, and that it was accordingly 
reclassified to Moderate ozone nonattainment status.\10\ Colorado 
submitted SIP revisions to the EPA on May 31, 2017 to meet the Denver 
Area's requirements under the Moderate classification.\11\ The EPA took 
final action on July 3, 2018, approving the majority of the May 31, 
2017 submittal, but deferring action on portions of the submitted Reg. 
7 RACT rules.\12\ On February 24, 2021, the EPA took final action 
approving additional RACT SIP

[[Page 32658]]

obligations for Moderate ozone nonattainment areas.\13\
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    \10\ Final rule, Determinations of Attainment by the Attainment 
Date, Extensions of the Attainment Date, and Reclassification of 
Several Areas for the 2008 Ozone National Ambient Air Quality 
Standards, 81 FR 26697 (May 4, 2016).
    \11\ CAA section 182, 42 U.S.C. 7511a, outlines SIP requirements 
applicable to ozone nonattainment areas in each classification 
category. Areas classified Moderate under the 2008 8-hour ozone 
NAAQS had a submission deadline of January 1, 2017 for these SIP 
revisions. 81 FR at 26699.
    \12\ 83 FR at 31068.
    \13\ 86 FR 11125.
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    Areas that were designated as Moderate nonattainment were required 
to attain the 2008 8-hour ozone NAAQS no later than July 20, 2018, 
based on 2015-2017 monitoring data.\14\ On December 26, 2019, the EPA 
published its determination that the Denver Area, among other areas, 
had failed to attain the 2008 8-hour ozone NAAQS by the attainment 
deadline, and that it was accordingly reclassified to Serious ozone 
nonattainment status.\15\
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    \14\ See 40 CFR 51.903.
    \15\ Final rule, Finding of Failure To Attain and 
Reclassification of Denver Area for the 2008 Ozone National Ambient 
Air Quality Standard, 84 FR 70897 (Dec. 26, 2019); see 40 CFR 
81.306.
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SIP Control Measures, Reg. 7

    Colorado's Reg. 7, entitled ``Control of Ozone via Ozone Precursors 
and Control of Hydrocarbons via Oil and Gas Emissions,'' contains 
general RACT requirements as well as specific emission limits 
applicable to various industries. The EPA approved the repeal and re-
promulgation of Reg. 7 in 1981,\16\ and has approved various revisions 
to parts of Reg. 7 over the years. In 2008, the EPA approved revisions 
to the control requirements for condensate storage tanks in Section 
XII,\17\ and later approved revisions to Reg. 7, Sections I through XI 
and Sections XIII through XVI.\18\ The EPA also approved Reg. 7 
revisions to Section XVII.E.3.a establishing control requirements for 
rich-burn reciprocating internal combustion engines.\19\ In 2018 the 
EPA approved Reg. 7 revisions in Sections XII (VOC emissions from oil 
and gas operations) and XIII (emission control requirements for VOC 
emissions from graphic art and printing processes), as well as non-
substantive revisions to numerous other parts of the regulation.\20\
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    \16\ Final rule, Colorado: Approval and Promulgation of State 
Implementation Plans, 46 FR 16687 (March 13, 1981).
    \17\ Final rule, Approval and Promulgation of Air Quality 
Implementation Plans; State of Colorado; Regulation No. 7, Section 
XII, Volatile Organic Compounds From Oil and Gas Operations, 73 FR 
8194 (Feb. 13, 2008).
    \18\ Final rule, Approval and Promulgation of State 
Implementation Plans; State of Colorado; Attainment Demonstration 
for the 1997 8-Hour Ozone Standard, and Approval of Related 
Revisions, 76 FR 47443 (Aug. 5, 2011).
    \19\ Final rule, Approval and Promulgation of Implementation 
Plans; State of Colorado; Regional Haze State Implementation Plan, 
77 FR 76871 (Dec. 31, 2012).
    \20\ See 83 FR at 31068, 31071.
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    Most recently, in 2021 the EPA approved Reg. 7 revisions in 
Sections I (Applicability), IX (Surface Coating Operations), X (Use of 
Cleaning Solvents), XIII (Graphics Arts and Printing), XVI (Controls of 
Emissions from Stationary and Portable Engines and Other Combustion 
Equipment in the 8-Hour Ozone Control Area), and XIX (Control of 
Emissions from Specific Major Sources of VOC and/or NO<INF>X</INF> in 
the 8-hour Ozone Control Area). Revisions to incorporation by reference 
dates to rules and reference methods in Sections II, VI, VIII, IX, X, 
XII, XIII, XVI and XVII were also approved, as well as non-substantive 
revisions to numerous other parts of the regulation.\21\
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    \21\ 86 FR 11125 (Feb. 24, 2021).
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III. Summary of the State's SIP Submittals

    We are proposing to take action on Colorado SIP submittals made on 
four three different dates:

May 14, 2018 Submittal

    This submittal contains amendments to Reg. 7 Sections XII (Volatile 
Organic Compound Emissions from Oil and Gas Operations) and XVIII 
(Natural Gas-Actuated Pneumatic Controllers Associated with Oil and Gas 
Operations) to meet RACT for oil and gas sources covered by the EPA's 
2016 Oil and Gas CTG.\22\
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    \22\ Control Techniques Guidelines for the Oil and Natural Gas 
Industry, EPA-453/B-16-001 (Oct. 2016).
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May 8, 2019 Submittal

    This submittal contains typographical, grammatical, and formatting 
corrections to Reg. 7 Sections XII and XVIII that were not acted on in 
our February 24, 2021 action.\23\
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    \23\ 86 FR 11125.
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May 13, 2020 Submittal

    This submittal includes a full reorganization of Reg. 7 into Parts 
A-E, and amends oil and gas storage tank requirements to establish a 
storage tank control threshold, updates storage tank monitoring 
requirements, and aligns related recordkeeping and reporting. The 
submittal also updates RACT requirements for major sources of VOC and 
NO<INF>X</INF> in the DMNFR area, including expanded categorical 
combustion equipment requirements in Part E, Section II (formally 
Section XVI.D.) and new categorical general solvent use requirements in 
Part C, Section II (formerly Section X.). The submittal also includes 
updates to the requirements for gasoline transport truck testing and 
vapor control systems, and contains typographical, grammatical, and 
formatting corrections throughout.

IV. Procedural Requirements

    The CAA requires that states meet certain procedural requirements 
before submitting SIP revisions to the EPA, including the requirement 
that states adopt SIP revisions after reasonable notice and public 
hearing.\24\
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    \24\ CAA section 110(a)(2), 42 U.S.C. 7410(a)(2),
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    For the May 14, 2018 submittal, the AQCC provided notice in the 
Colorado Register on July 22, 2017 and held public hearings on the 
revisions on October 19 and 20, 2017. The Commission adopted the SIP 
revisions on November 17, 2017. The SIP revisions became state-
effective on December 30, 2017.
    For the May 8, 2019 submittal, the AQCC provided notice in the 
Colorado Register on August 18, 2018 and held a public hearing on the 
revisions on November 15, 2018. The Commission adopted the SIP 
revisions on November 15, 2018. The revisions became state-effective on 
January 14, 2019.
    For the May 13, 2020 submittal, the AQCC provided notice in the 
Colorado Register on September 25, 2019 and held public hearings on the 
revisions on December 17-19, 2019. The Commission adopted the SIP 
revisions on December 19, 2019. The SIP revisions became state-
effective on February 14, 2020.
    Accordingly, we propose to find that Colorado met the CAA's 
procedural requirements for reasonable notice and public hearing.

V. Reasonably Available Control Technology (RACT) Analysis

A. Background

    The CAA requires that SIPs for nonattainment areas implement RACT 
for each category of VOC sources in the area covered by a CTG and all 
other major stationary sources of VOC.\25\ The EPA has defined RACT as 
the lowest emissions limitation that a particular source is capable of 
meeting by the application of control technology that is reasonably 
available, considering technological and economic feasibility.\26\ The 
CAA amendments of 1990 introduced the requirement for existing major 
stationary sources of NO<INF>X</INF> in nonattainment areas to install 
and operate NO<INF>X</INF> RACT.\27\
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    \25\ CAA section 182(b)(2).
    \26\ Proposed rule, General Preamble for Proposed Rulemaking on 
Approval of Plan Revisions for Nonattainment Areas--Supplement (on 
Control Techniques Guidelines), 44 FR 53761, 53762 (Sep. 17, 1979).
    \27\ CAA Section 182(f).
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    The EPA provides guidance concerning what types of controls can 
constitute RACT for a given source

[[Page 32659]]

category by issuing CTG and Alternative Control Techniques (ACT) 
documents.\28\ States must submit a SIP revision requiring the 
implementation of RACT for each source category in the area for which 
the EPA has issued a CTG, and for any major source in the area not 
covered by a CTG.\29\
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    \28\ See https://www.epa.gov/ground-level-ozone-pollution/control-techniques-guidelines-and-alternative-control-techniques 
(accessed May 20, 2021) for a list of the EPA-issued CTGs and ACTs 
(also available within the docket).
    \29\ See CAA section 182(b)(2), 42 U.S.C. 7511a(b)(2)). See also 
Note, RACT Qs & As--Reasonably Available Control Technology (RACT): 
Questions and Answers, William Harnett, Director, Air Quality Policy 
Division, EPA (May 2006), available at https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20060518_harnett_ract_q&a.pdf.
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    For a Serious nonattainment area, a major stationary source is one 
that emits, or has the potential to emit, 50 tons per year (tpy) or 
more of VOC or NO<INF>X</INF>.\30\ RACT can be adopted in the form of 
emission limitations or ``work practice standards or other operation 
and maintenance requirements,'' as appropriate.\31\ In assessing RACT 
requirements under the Serious classification, the Colorado Air 
Pollution Control Division (Division) evaluated 31 major sources in 
their Technical Support Document (TSD),\32\ in addition to the major 
sources evaluated under the Moderate classification.
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    \30\ See CAA sections 182(c), 42 U.S.C. 7511a(c).
    \31\ See Memorandum, ``Approval Options for Generic RACT Rules 
Submitted to Meet the non-CTG VOC RACT Requirement and Certain 
NO<INF>X</INF> RACT Requirements,'' Sally Shaver, Director, Air 
Quality Strategies & Standards Division, EPA (Nov. 7, 1996), 
available at https://www.epa.gov/sites/production/files/2016-08/documents/shavermemogenericract_7nov1996.pdf.
    \32\ Technical Support Document for Reasonably Available Control 
Technology for Major Sources, Dec. 11, 2019. P. 2134 of the May 13, 
2020 submittal.
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    On October 20, 2016, the EPA issued final CTGs for reducing VOC 
emissions from existing oil and natural gas equipment and 
processes.\33\ Under the schedule in the oil and gas CTG, revisions to 
SIP RACT provisions for sources covered by the CTG were due on October 
27, 2018. Sources covered by the CTG include those located in 2008 
ozone NAAQS nonattainment areas classified as Moderate (or higher). The 
emissions controls determined by the State to be RACT for sources 
covered by the oil and gas CTG were required to be implemented as soon 
as practicable, but no later than January 1, 2021.\34\ In November 
2017, the Commission adopted revisions to Reg. 7 that addressed RACT 
requirements for each category of sources covered by the oil and gas 
CTG.
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    \33\ Notice of availability, Release of Final Control Techniques 
Guidelines for the Oil and Natural Gas
    Industry, 81 FR 74798 (Oct. 27, 2016). See also Control 
Techniques Guidelines for the Oil and Natural Gas Industry, EPA-453/
B-16-001 (Oct. 2016).
    \34\ Docket ID No. EPA-HQ-OAR-2015-0216-0238.
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    In December 2019, the Commission adopted new SIP requirements to 
include provisions that implement RACT for some major sources of VOC 
and NO<INF>X</INF> by incorporating by reference new source performance 
standards (NSPS) and/or national emission standards for hazardous 
pollutants (NESHAP) requirements for specific points at major sources; 
requiring specific sources to provide RACT analyses to the Division for 
specified facilities and/or emission points to inform future 
categorical RACT rulemakings; expanding categorical combustion 
equipment requirements in Part E, Section II. (formerly Section XVI.D.) 
to facilities with NOx emissions greater than or equal to 50 tpy; and 
establishing categorical RACT requirements for general solvent use.

B. Evaluation

    As part of its May 14, 2018 and May 13, 2020 submittals, the 
Division conducted RACT analyses to demonstrate that the RACT 
requirements for the oil and gas CTG and certain major sources in the 
DMNFR 2008 8-hour ozone NAA have been fulfilled. The Division conducted 
these RACT analyses for VOC and NO<INF>X</INF> by listing the state 
regulation that implements or exceeds RACT requirements for the CTG 
category or non-CTG category at issue, and by detailing the basis for 
concluding that these regulations fulfill RACT, through comparison with 
established RACT requirements described in the CTG and ACT guidance 
documents. A summary of our proposed action with respect to each RACT 
category follows.

              Table 1--Source Categories, Proposed Action, and Corresponding Sections of Submittals
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               Category                         Proposed action              Location of RACT demonstration
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Aerospace.............................  Approval......................  Negative declaration. p. 6-3 of
                                                                         Colorado's Serious State Implementation
                                                                         Plan for the Denver Metro and North
                                                                         Front Range Ozone Nonattainment Area.35
General solvent use at major sources..  Approval......................  pp. 619-620, 706, 2800, 2803 and
                                                                         Technical Support Document for
                                                                         Reasonably Available Control Technology
                                                                         for Major Sources (document number 56,
                                                                         p. 2134) of the May 13, 2020
                                                                         submission.
Oil and gas...........................  Approval......................  Technical Support Document for
                                                                         Reasonably Available Control Technology
                                                                         for the Oil and Gas Industry (document
                                                                         set 38) of the May 14, 2018 submittal.
                                                                         pp. 417-425 of the May 13, 2020
                                                                         submittal.
Emissions from stationary internal      Approval......................  pp. 619, 622, 724, 2800-2801, 2803 and
 combustion engines and flares at                                        Technical Support Document for
 certain major sources.                                                  Reasonably Available Control Technology
                                                                         for Major Sources (document number 56,
                                                                         p. 2134) of the May 13, 2020
                                                                         submission.
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Cited materials are in the docket for this action.

    In our July 3, 2018 and February 24, 2021 rulemakings, we approved 
Colorado's demonstration of RACT for certain VOC CTG sources \36\ for 
the 2008 8-hour ozone standard. Today we are taking action on the RACT 
demonstrations for Oil and Gas CTG categories and certain additional 
non-CTG VOC and NOx sources and categories. We have reviewed Colorado's 
new and revised VOC rules for the source categories covered by the Oil 
and Gas CTG, and for major sources of non-CTG VOC and NOx sources for 
the 2008 8-hour ozone NAAQS, and the demonstrations submitted by 
Colorado. Based on this review we propose to find that these rules are 
consistent with the

[[Page 32660]]

control measures, definitions, recordkeeping, and test methods in the 
CTG and the CAA, and that they satisfy CAA RACT requirements for the 
categories in question.\37\
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    \35\ See Colorado's March 22, 2021 submittal, document set 16 
(in the docket for this action).
    \36\ 83 FR at 31069-31070; see Proposed Rule, Promulgation of 
State Implementation Plan Revisions; Colorado; Attainment 
Demonstration for the 2008 8-Hour Ozone Standard for the Denver 
Metro/North Front Range Nonattainment Area, and Approval of Related 
Revisions, 83 FR 14807, 14814-141815, Tables 5 and 6 (Apr. 6, 2018).
    \37\ See https://www.epa.gov/ground-level-ozone-pollution/ract-information.
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1. RACT for CTG Sources
    Table 2 contains the CTG source category, the EPA reference 
document, and the corresponding sections of Reg. 7 that fulfill the 
applicable RACT requirements for the EPA-issued CTGs.\38\ Colorado's 
Reg. 7 contains SIP-approved \39\ and submitted revisions (see Section 
VI of this document); we propose to find that these revisions meet RACT 
requirements for the source category listed in Table 2.
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    \38\ See the EPA's TSD for a full analysis of Colorado's rules 
as they relate to the EPA's guidelines and available technical 
information.
    \39\ See 76 FR at 47443 and 83 FR at 31069-31070.
    \40\ P. 2134 of the May 13, 2020 submittal.
    \41\ See the EPA's TSD for a full analysis of Colorado's rules 
as they relate to the EPA's guidelines and available technical 
information.
    \42\ Colorado's major source RACT analysis can be found on pp. 
1119-1120 and 1142-1149 of the May 31, 2017 submittal and the 
Technical Support Document for Reasonably Available Control 
Technology for Major Sources, November 17, 2016 (pp. 2990-3273 of 
May 31, 2017 submittal).

Table 2--Source Category, the EPA's CTG Reference Document, and Corresponding Sections of Reg. 7 Fulfilling RACT
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                                                                                     Reg. 7 sections fulfilling
  Source category in DMNFR area       CTG reference document        Date of CTG                 RACT
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Oil and Gas.....................  Control Techniques Guidelines             2016   Sections XII, XVIII, and
                                   for the Oil and Natural Gas                      revised Section D (proposed
                                   Industry.                                        for approval in this
                                                                                    action).
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    We have reviewed the emission limitations and control requirements 
for the above source category and compared them against the EPA's CTG 
document and available technical information in CTG dockets. The EPA 
has also evaluated the submitted rules and has determined that they are 
consistent with the CAA, the EPA's regulations, and the EPA's policies. 
For more information, see the EPA TSD prepared in conjunction with this 
action. Based on the information in the record, we propose to find that 
the corresponding sections in Reg. 7 provide for the lowest emission 
limitation through application of control techniques that are 
reasonably available considering technological and economic 
feasibility. Therefore, we propose to find that the control 
requirements for the oil and gas source category are RACT for all 
affected sources in the DMNFR Area under the 2008 8-hour ozone NAAQS.
2. RACT for Non-CTG Major Sources
    In Colorado's Technical Support Document for Reasonably Available 
Control Technology for Major Sources,\40\ Colorado identified a list of 
major non-CTG VOC and NO<INF>X</INF> sources in the DMNFR Area subject 
to RACT requirements under a Serious classification. For major VOC and 
NO<INF>X</INF> sources subject to nonattainment area RACT review, 
Colorado used the construction permit thresholds established in the 
State's Reg. 3 for determining which emission points to review. 
Accordingly, emission points exceeding two tpy of VOC at a major VOC 
source and five tpy of NO<INF>X</INF> at a major NO<INF>X</INF> source, 
as reported on a source's Air Pollutant Emission Notice, and that were 
not part of the Moderate RACT review, were evaluated. We have reviewed 
the State's May 13, 2020 submittal and find its approach to including 
these sources in the inventory acceptable. To satisfy the Serious RACT 
SIP requirement to establish RACT for all existing major sources of VOC 
and/or NO<INF>X</INF> in the DMNFR Area, the Commission incorporated by 
reference several NSPS and NESHAP regulations. The Division also 
expanded the stationary combustion equipment standards and developed 
new general solvent use requirements, based on a detailed review of 
available information on major NO<INF>X</INF> and VOC sources in the 
DMNFR Area, an examination of the EPA RACT/Best Available Control 
Technology/Lowest Achievable Emission Rate Clearinghouse for similar 
emission points, and consideration of CAA section 182(b) RACT 
requirements for other ozone nonattainment areas. Table 3 contains a 
list of non-CTG source categories, the EPA's reference documents, and 
the corresponding sections of Reg. 7 that are proposed for approval in 
this action to fulfill RACT requirements (see Section VI of this 
document).\41\

     Table 3--Source Categories, the EPA's Reference Documents, and
 Corresponding Sections of Reg. 7 Proposed for Approval To Fulfill RACT
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                               The EPA's reference
Source category in the DMNFR       document or         Reg. 7 sections
           area 42               regulation (if        fulfilling RACT
                                   applicable)
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General solvent use at major  ....................  Part C, Section II.F
 sources.                                            (proposed for
                                                     approval in this
                                                     action).
Stationary internal           NOX Emissions from    Applicable
 combustion engines.           Stationary Internal   provisions in Part
                               Combustion Engines    E, Section II.
                               (EPA-453/R-93-032).
Flares......................  40 CFR 60, Subpart    Part E, Section
                               A, Section 60.18      III.B.2.
                               General Provisions,
                               General control
                               device and work
                               practice
                               requirements.
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    We have reviewed the emission limitations and control requirements 
for the source categories in Table 3 and compared them to the EPA's 
regulations, ACT documents, available technical information, and 
guidelines. The EPA has also evaluated the submitted rules \43\ and has 
determined that they are consistent with the CAA, the EPA's 
regulations, and the EPA's policies. For more information, see the EPA 
TSD prepared in conjunction with this action. Based on the information 
in the record, we propose to find that the corresponding sections in 
Reg. 7

[[Page 32661]]

provide for the lowest emission limitation through application of 
control techniques that are reasonably available considering 
technological and economic feasibility. Therefore, we propose to find 
that the control requirements for the source categories identified in 
Table 3 are RACT for all affected sources in the DMNFR Area under the 
2008 8-hour ozone NAAQS.

VI. The EPA's Evaluation of SIP Control Measures in Reg. 7

    We evaluated Colorado's May 14, 2018, May 8, 2019, and May 13, 2020 
submittals regarding revisions to the State's Reg. 7 to meet RACT 
requirements for various source categories. Revisions to Reg. 7 include 
expansion of categorical combustion equipment requirements; 
incorporation by reference of certain NSPS and NESHAP requirements for 
engines and landfill gas flares; RACT analysis requirements for 
specified facilities and/or emission points; emission control 
requirements for general solvent use; and updated requirements for 
gasoline transport truck testing and vapor control systems. The 
revisions establish RACT requirements for the oil and gas CTG category 
and emission points at major sources of VOC and NO<INF>X</INF> in the 
DMNFR Area. Reg. 7 revisions also add incorporation by reference dates 
to rules and reference methods; reorganize and renumber the regulation; 
and correct typographical, grammatical, and formatting errors. For ease 
of review, Colorado submitted the full text of Reg. 7 as SIP revisions 
(with the exception of provisions designated ``State Only''). The EPA 
is only seeking comment on Colorado's proposed substantive changes to 
the SIP-approved version of Reg. 7, which are described below. We are 
not seeking comment on incorporation into the SIP of the revised 
portions of the regulation that were previously approved into the SIP 
and have not been substantively modified by the State as part of any of 
these submittals.
    As noted above, Colorado designated various parts of Reg. 7 State 
Only, and in Section I.A.1.c indicated that sections designated State 
Only are not federally enforceable. The EPA concludes that provisions 
designated State Only have not been submitted for the EPA's approval, 
but for informational purposes. Hence, the EPA is not proposing to act 
on the portions of Reg. 7 designated State Only, and this proposed rule 
does not discuss them further except as relevant to discussion of the 
portions of the regulation that Colorado intended to be federally 
enforceable.

A. Evaluation

1. May 14, 2018 SIP Submittal
    The State's May 14, 2018 SIP submittal contains amendments to Reg. 
7, Sections II.B., XII and XVIII to meet RACT for oil and gas sources 
covered by the EPA's 2016 Oil and Gas CTG. The submittal also includes 
clarifying revisions and typographical, grammatical, and formatting 
corrections throughout Reg. 7. We propose to approve the revisions to 
Sections XII and XVIII included in Colorado's May 14, 2018 submittal as 
identified in Table 5. All remaining Sections of the May 14, 2018 
submittal were approved with our February 24, 2021 action.\44\ Below, 
we describe in detail Colorado's proposed revisions and the basis for 
our proposed approval of them. Additional analysis on how revisions 
meet RACT requirements can be found in the TSD for this action.
---------------------------------------------------------------------------

    \44\ 86 FR 11125 (Feb. 24, 2021).
---------------------------------------------------------------------------

a. Section II
    Section II includes general provisions for Reg. 7. The revisions to 
Section II.B. clarify that the Section XII.L. hydrocarbon threshold and 
Section XVIII natural gas emission standards serve as VOC indicators 
and that the SIP does not regulate hydrocarbon emissions.
    We propose to find that the revisions clarify Sections XII.L., 
XVIII.C.1. and XVIII.C.2. and are consistent with CAA requirements and 
CTGs. We therefore propose to approve the changes in Section II.B.
b. Section XII
    Section XII regulates VOC emissions from, and establishes RACT for, 
oil and gas operations. Section XII applies to operations that involve 
the collection, storage, or handling of condensate in the DMNFR Area. 
Changes to Sections XII.A. through XII.D. and XII.F. through XII.F.L. 
include addition of definitions for terms used in oil and gas 
operations; clarifications to Colorado's ozone season; updates to the 
leak detection and repair program; new provisions for centrifugal and 
reciprocating compressors, natural gas driven diaphragm pumps, and 
fugitive emissions at well production facilities and natural gas 
compressor stations; and minor clerical \45\ revisions that do not 
affect the substance of the requirements.
---------------------------------------------------------------------------

    \45\ When we describe changes as clerical in this proposed 
action, we are referring to changes like section renumbering; 
alphabetizing of definitions; minor grammatical, editorial, and 
typographical revisions; and changes in capitalization.
---------------------------------------------------------------------------

(i) Section XII.B.
    Section XII.B. contains definitions specific to oil and gas 
operations in Section XII. New definitions were added for ``approved 
instrument monitoring method,'' ``centrifugal compressor,'' 
``component,'' ``connector,'' ``custody transfer,'' ``infra-red 
camera,'' ``natural gas compressor station,'' ``natural gas-driven 
diaphragm pump,'' ``natural gas processing plant,'' ``reciprocating 
compressor,'' and ``well production facility.'' The definitions are 
clear, straightforward, and accurate.
(ii) Section XII.C.1.
    Section XII.C.1. includes provisions that are generally applicable 
to Section XII. Section XII.C.1.e.(iv) adds a new requirement for 
combustion devices installed on or after January 1, 2018 and used to 
comply with Sections XII.J. or XII.K. to be equipped with an 
operational auto-igniter upon installation. We propose to find that the 
revisions to Section XII.C.1. meet CAA and RACT requirements, and that 
they strengthen the SIP.
(iii) Section XII.G.
    Section XII.G. includes requirements for natural gas-processing 
plants in the 8-hour Ozone Control Area. Section XII.G.1. updates the 
leak detection and repair (LDAR) program applicable to equipment leaks 
at natural gas processing plants in the DMNFR Area by requiring owners 
or operators to comply with 40 CFR part 60 (NSPS), Subparts OOOO or 
OOOOa, instead of complying with NSPS Subpart KKK, which is an earlier 
NSPS and less stringent. Subpart KKK requires sources to implement a 
NSPS Subpart VV level LDAR program, while Subpart OOOO requires sources 
to implement a NSPS Subpart VVa level LDAR program. The oil and gas CTG 
recommends a Subpart VVa level LDAR program for equipment at natural 
gas processing plants. Section XII.G.3. updates compliance dates for 
owners and operators of existing natural gas processing plants subject 
to Section XII.G. requirements. We propose to find that the revisions 
to Section XII.G. meet CAA and RACT requirements, and that they 
strengthen the SIP.
(iv) Section XII.H.
    Section XII.H. sets forth emission reduction requirements for 
glycol natural gas dehydrators. Section XII.H.6. establishes reporting 
requirements for sources subject to Section XII.H. The Commission 
revised references to ``ozone season'' in Section and XII.H.6. to 
reflect that the requirements now apply year-round, including during 
the

[[Page 32662]]

months of May to September.<SUP>46 47</SUP> We propose to find that the 
revisions to Section XII.H. strengthen the SIP and meet CAA 
requirements.
---------------------------------------------------------------------------

    \46\ In October 2015, the EPA finalized a revision to the ozone 
NAAQS that revised the length of Colorado's ozone season to year-
round (Final rule, National Ambient Air Quality Standards for Ozone, 
80 FR 65292 (Oct. 26, 2015)).
    \47\ We are also approving a similar provision in Section 
XII.F.4. The provision applies to the system-wide control strategy 
for condensate storage tanks. In this action, we are proposing 
approval of the control strategy for individual storage tanks in new 
Part D, Section I.D. which replaces the system-wide strategy 
controls in Section XII.
---------------------------------------------------------------------------

(v) Section XII.J.
    Section XII.J. contains new provisions for centrifugal and 
reciprocating compressors. Section XII.J.1.a. requires that by January 
2, 2018, VOC emissions from wet seal fluid degassing systems on wet 
seal centrifugal compressors located between the wellhead and the point 
of custody transfer to the natural gas transmission and storage segment 
must be reduced by at least 95%. Section XII.J.1.b. requires wet seal 
fluid degassing systems to be equipped with continuous, impermeable 
covers that are connected through a closed vent system that routes 
emissions from the wet seal fluid degassing system to the process or 
control device. Section XII.J.1.c. requires annual visual inspections 
of the cover and closed vent systems for defects that could result in 
air emissions.
    Under Section XII.J.1.d., owners or operators must conduct annual 
EPA Method 21 inspections of covers and closed vent systems to 
determine whether they operate with VOC emissions less than 500 ppm. 
Section XII.J.1.e. requires first attempts at repair to occur no later 
than five days after detecting defects or leaks, and repairs to be 
completed no later than 30 days after detection. Section XII.J.1.f. 
sets forth criteria for delaying inspection or repair due to unsafe 
conditions and accessibility issues. Owners or operators are required 
to maintain records of each cover or closed vent system that is unsafe 
or difficult to inspect and schedule for inspection when circumstances 
allow.
    Section XII.J.1.h. includes recordkeeping requirements to 
demonstrate compliance with Section XII.J.1. Owners and operators must 
maintain records for a minimum of five years. As an alternative to the 
inspection, repair, and recordkeeping provisions, owners and operators 
may inspect, repair, and document cover and closed vent systems in 
accordance with the LDAR program in Section XII.L. Section XII.J.1.j. 
allows owners and operators to comply with emissions, inspections, 
repair, and recordkeeping provisions of an NSPS including Subparts OOOO 
and OOOOa in lieu of Sections XII.J.1.a. through i.
    Section XII.J.2. contains provisions for reciprocating compressors. 
Section XII.J.2.a. requires that the rod packing on reciprocating 
compressors located between the wellhead and the point of custody 
transfer to the natural gas transmission and storage segment be 
replaced every 26,000 hours of operation or every 36 months. Under 
Section XII.J.2.a., owners or operators of existing reciprocating 
compressors at natural gas processing plants were required to begin 
monitoring the reciprocating compressor hours of operation on January 
1, 2018 and conduct the first rod packing replacement before January 1, 
2021, or route emissions to a process beginning May 1, 2018.
    Section XII.J.2.b. allows owners or operators the option to reduce 
VOC emissions by routing reciprocating compressor emissions using a rod 
packing emissions collection system that operates under negative 
pressure and routes the rod packing emissions through a closed vent 
system to a process. Owners and operators must conduct annual visual 
inspections of the cover and closed vent systems for defects that could 
result in air emissions. Section XII.J.2.b.(ii) requires owners and 
operators to conduct annual EPA Method 21 inspections of the cover and 
closed vent system to determine whether they operate with VOC emissions 
less than 500 ppm. Section XII.2.e. allows owners and operators to 
comply with emissions, inspections, repair, and recordkeeping 
provisions of an NSPS in lieu of Sections XII.J.2.a. through d.
    First attempts at repair must be made within five days of 
discovery, and repairs must be completed within 30 days unless one of 
the justifications for delay of repair in Section XII.J.2.b.(iv) 
applies. Owners or operators may delay subsequent repair attempts of 
equipment where, during a scheduled shutdown, the owner or operator 
unsuccessfully repaired the leak requiring repair if repair is 
completed within two years of discovery. Delayed inspection or repairs 
of the closed vent system may occur under certain safety, 
accessibility, and feasibility circumstances described in Sections 
XII.J.2.b.(iv)(A) through (D).
    Section XII.J.2.c. includes recordkeeping requirements to 
demonstrate compliance with Section XII.J.2. Owners and operators must 
maintain records for a minimum of five years. As an alternative to the 
inspection, repair, and recordkeeping provisions, Section XII.J.2.d. 
allows owners and operators to inspect, repair, and document cover and 
closed vent systems in accordance with the LDAR program in Section 
XII.L. Section XII.J.2.e. allows owners and operators to comply with 
emissions, inspections, repair, and recordkeeping provisions of an 
NSPS, including Subparts OOOO and OOOOa.
    We propose to find that the provisions in the new Section XII.J. 
strengthen the SIP and meet CAA and RACT requirements.
(vi) Section XII.K
    Section XII.K adds requirements for pneumatic pumps. Section 
XII.K.1 requires that natural gas-driven diaphragm pneumatic pumps at 
natural gas processing plants have a VOC compound emissions rate of 
zero. Section XII.K.2. establishes a May 1, 2018 effective date for 
owners or operators to reduce emissions from natural gas-driven 
diaphragm pneumatic pumps at well production facilities by 95% within 
30 days of startup of the control device or route emissions to a 
process at the well production facility. Pneumatic pump emissions must 
be routed to the existing control device even if is unable to achieve a 
95% emission reduction if it is technically infeasible to route 
emissions to a process. Section XII.K.2.b. requires a 95% reduction 
from pneumatic pumps within 30 days of startup upon installation of a 
control device or once routing emissions to a process becomes 
technically feasible. Pneumatic pump emissions are exempt from controls 
if an engineering assessment by a qualified professional engineer 
determines that routing a pneumatic pump to a control device or process 
is technically infeasible. Pneumatic pumps routing emissions to the 
process or control device must connect through a closed vent system.
    Sections XII.K.2.e. through h. require annual visual and EPA Method 
21 inspections of the closed vent system. First attempts at repairs 
must be made within five days of discovery, and repairs must be 
completed within 30 days unless one of the justifications for delay of 
repair in Sections XII.K.2.h. applies. Delayed inspection or repairs of 
the closed vent system may occur under certain safety, accessibility, 
and feasibility circumstances described in Sections XII.K.2.h.(i) 
through (iv).
    Section XII.K.3. includes recordkeeping requirements to demonstrate 
compliance with Section XII.K. Owners and operators must

[[Page 32663]]

maintain records for a minimum of five years. As an alternative to the 
inspection, repair, and recordkeeping provisions, XII.K.4. allows 
owners and operators to inspect, repair, and document cover and closed 
vent systems in accordance with the LDAR program in Section XII.L. 
Section XII.K.5. allows owners and operators to comply with emissions, 
inspections, repair, and recordkeeping provisions of an NSPS in lieu of 
Sections XII.K.1. and XII.K.4.
    We propose to find that the provisions in the new Section XII.K. 
strengthen the SIP and meet CAA and RACT requirements.
(vii) Section XII.L
    Section XII.L. establishes a new leak detection and repair (LDAR) 
program for well production facilities and natural gas compressor 
stations in the DMNFR Area.
    This program, which we are now reviewing for approval into the SIP, 
took effect under state law beginning June 30, 2018. Under the LDAR 
program, owners or operators of natural gas compressor stations must 
inspect components for leaks using an approved instrument monitoring 
method (AIMM) at least quarterly.\48\ As defined in new section 
XII.B.3, AIMM means an infra-red camera, EPA Method 21, or another 
``instrument based monitoring method or program'' that is approved in 
accordance with Section XII.L.8, discussed below. Initial inspections 
for leaks from components at natural gas compressor stations 
constructed on or after June 30, 2018 must be conducted no later than 
90 days after the facility commences operation and at least quarterly 
thereafter.
---------------------------------------------------------------------------

    \48\ The SIP at Reg. 7, Section XII.E.3, already required an 
``audio, visual, olfactory'' (AVO) inspection required for storage 
tanks subject to control requirements. That requirement remains in 
effect.
---------------------------------------------------------------------------

    Owners or operators at well production facilities with uncontrolled 
actual VOC emissions greater than or equal to one ton per year and less 
than or equal to six tons per year must inspect components for leaks 
using an AIMM at least annually. Well production facilities with 
uncontrolled VOC emissions greater than six tons per year must be 
inspected at least semi-annually. Sections XII.L.2.c. and Section 
XII.L.2.d. set forth the criteria for determining inspection frequency 
and the timing of initial inspections. Initial inspections for well 
production facilities constructed on or after June 30, 2018 must be 
conducted no sooner than 15 days and no later than 30 days after the 
facility commences operation. Monitoring components is not required 
under certain safety, accessibility, and feasibility circumstances 
described in Sections XII.L3.a. through c.
    Section XII.L.4. establishes thresholds for leaks requiring repair 
under Section XII.L.5. The first attempt to repair an identified leak 
must be made within five working days of discovery and completed within 
30 days unless one of the justifications for delay of repair in 
Sections XII.L.5.a(i) through (iii) applies. Leaks must be re-monitored 
within 15 working days of the repair.
    Section XII.L.6. requires owners or operators to keep records to 
demonstrate compliance with the LDAR program and to maintain those 
records for a minimum of five years. Records include documentation of 
the initial approved AIMM inspection; facility identification 
information; leaks requiring repair and monitoring method used to 
determine presence of the leak; dates of first attempt to repair; dates 
and types of repairs; delayed repair lists; re-monitoring dates and 
results; and lists of components designated as unsafe, difficult, or 
inaccessible to monitor.
    Section XII.L.7. requires that each facility's owner or operator 
submit an annual LDAR report to ensure that the data submitted to the 
Division accurately represents and summarizes the activities and 
effectiveness of the LDAR program. Reports should include the number of 
inspections, leaks requiring repair, leaking component type, and 
monitoring method by which the leaks were found.
    Section XII.L.8. describes the process for review and approval of 
alternative AIMM for use as a part of the LDAR program. The provisions 
allow the use of an alternative AIMM in lieu of or in combination with 
the EPA-approved AIMM (i.e., infra-red cameras or Method 21), if 
certain conditions are met under Section XII.L.8.a. and if the Division 
approves the proposal.
    Because the alternative AIMM regulation allows the authorization, 
outside of the SIP approval process, of a leak detection method not 
specified in the submitted regulatory language or elsewhere in the SIP, 
we must consider whether it impermissibly allows the state agency to 
revise the SIP at its own discretion. Concerns with such rules, often 
known as ``director's discretion'' provisions, are discussed in detail 
in EPA's 2015 final rule responding to a petition for rulemaking 
concerning how SIPs treat excess emissions during periods of startup, 
shutdown, or malfunction (SSM), often referred to as the ``SSM SIP 
Call'' rulemaking.\49\ As explained in the SSM SIP Call, the EPA 
interprets the CAA as prohibiting ``SIP provisions that include 
unlimited director's discretion to alter the SIP emission limitations 
applicable to source.'' \50\ But the SSM SIP Call also explains that 
there are circumstances in which a director's discretion provision may 
be consistent with the CAA and fully approvable, including ``when the 
director's discretion authority is adequately bounded such that the EPA 
can ascertain in advance, at the time of approving the SIP provision, 
how the exercise of that discretion to alter the SIP emission 
limitations for a source could affect compliance with other CAA 
requirements.'' \51\ The EPA has long held this position. As explained 
in a 1996 EPA guidance document, it may be appropriate for states to 
approve equally stringent source-specific alternatives to SIP-approved 
requirements, when the SIP includes language ``to provide substantive 
criteria governing the State's exercise of the alternative requirement 
authority.'' \52\
---------------------------------------------------------------------------

    \49\ Final action, State Implementation Plans: Response to 
Petition for Rulemaking; Restatement and Update of EPA's SSM Policy 
Applicable to SIPs; Findings of Substantial Inadequacy; and SIP 
Calls to Amend Provisions Applying to Excess Emissions During 
Periods of Startup, Shutdown and Malfunction, 80 FR 33840, 33917-
33924 (June 12, 2015).
    \50\ Id. at 33917.
    \51\ Id. at 33918.
    \52\ White Paper Number 2 for Improved Implementation of the 
Part 70 Operating Permits Program (EPA OAQPS, March 5, 1996), 
Attachment B (``SIP Provisions For Establishing Alternative 
Requirements''), available at https://www.epa.gov/sites/production/files/2015-08/documents/wtppr-2.pdf.
---------------------------------------------------------------------------

    Here, the EPA's view is that the State rule provides sufficient 
specific, substantive criteria to allow the EPA to evaluate the use of 
discretion in advance. Most significantly, under the provisions of 
Section XII.L.8, alternative AIMM must be ``capable of achieving 
emission reductions that are at least as effective as the emissions 
reductions achieved using an IR camera or Method 21.'' This requirement 
ensures that the State may not use its discretion to approve a method 
that is less effective than the SIP baseline.\53\ That is, in 
implementing the alternative AIMM program according to its 
requirements, which we are proposing to make a part of the SIP, the 
State will be unable to weaken any SIP provisions.
---------------------------------------------------------------------------

    \53\ See Final Rule, Revisions to Air Plan; Arizona; Stationary 
Sources; New Source Review, 80 FR 67319, 67327 (Nov. 2, 2015) 
(approving rule as appropriately bounded because state agency ``does 
not have discretion to determine in which instances it will or won't 
apply the criteria'' in the regulation).

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

[[Page 32664]]

    It is important in reaching this conclusion that we are able to 
understand the State's process for determining whether an alternative 
AIMM is ``at least as effective'' as the two methods specified in the 
SIP. First, under the submitted rules at Section XII.L.8.a.(ii)(C), an 
alternative AIMM applicant must provide information on whether the 
proposed alternative is approved by other regulatory authorities, and 
for what application. This information will allow the State to assess 
the reliability and viability of the alternative. In addition, under 
Section XII.L.8.a.(ii)(D), the applicant must provide information, with 
supporting data, on the leak detection capabilities and limitations of 
the proposed alternative method. This data requirement is important to 
ensuring that the potential exercise of discretion in the alternative 
AIMM program is adequately bounded.
    The State has further explained this process in a guidance document 
provided to the EPA.\54\ As explained in this document, in evaluating 
effectiveness, Colorado assumes that a certain level of emission 
reductions would be achieved using either infrared camera or Method 21 
AIMM, on a periodic basis with increasing emission reductions under 
greater monitoring frequencies, and compares the anticipated results of 
the proposed alternative AIMM to those numbers.\55\ Testing and 
modeling of the alternative AIMM is required.\56\ Thus, the State's 
program includes a quantitative evaluation according to specified 
criteria.
---------------------------------------------------------------------------

    \54\ See Alternative AIMM Guidance & Procedures (CDPHE, Oct. 31, 
2019) (EPA-R08-OAR-2021-0262-0003).
    \55\ See Alternative AIMM Guidance at 6.
    \56\ In this respect the state's guidance, provided to EPA to 
assist in explaining the functioning of the state program, clarifies 
one arguable ambiguity in the submitted language. Specifically, the 
comma after ``data'' in XII.L.8.a.(ii)(I) leaves unclear whether the 
rule requires data or modeling, or data and modeling; the state's 
guidance makes clear that ``and'' is intended when it says that 
modeling should not be relied on exclusively for this demonstration, 
but that there should be testing as well. See also Letter from Garry 
Kaufman, Director, Air Pollution Control Division (March 24, 2021) 
providing clarifying information, available in the docket for this 
action.
---------------------------------------------------------------------------

    Additional safeguards and constraints in the alternative AIMM 
process include:
    <bullet> The Alternative AIMM approval has to be made based on a 
record.
    <bullet> The State must provide public notice of the proposed 
alternative.
    <bullet> Approved alternative AIMM is made available to the public 
on a state website: https://cdphe.colorado.gov/alternative-aimm-public-notices.
    One final feature of the State's alternative AIMM rule bears 
mentioning. It includes a requirement that the State agency submit the 
proposed alternative AIMM to the EPA for review. The alternative AIMM 
must receive the EPA's approval, but this approval may occur by default 
if the EPA does not disapprove the rule within six months. While this 
six-month EPA review period gives an additional opportunity for 
regulatory scrutiny of alternative AIMM proposals before approval, it 
is not equivalent to the SIP process, and is not the basis for our 
proposed approval of this action. Rather, it is because the alternative 
AIMM rules provide substantive criteria that constrain the State's 
exercise of discretion and allow the EPA to anticipate the impacts of 
the use of alternatives. For that reason, and as explained further 
above, we propose to approve the submitted new section XII.L.
    A detailed evaluation of Section XII as a whole is in the TSD for 
this action. We propose to find that the submitted revisions to Section 
XII meet CAA and RACT requirements, and that they strengthen the SIP.
c. Section XVIII
    Section XVIII regulates emissions from natural gas-actuated 
pneumatic controllers located at or upstream of natural gas processing 
plants, and establishes RACT requirements for oil and gas operations. 
Section XVIII.C.1. requires that all pneumatic controllers installed on 
or before February 1, 2009 upstream of natural gas processing plants in 
the DMNFR Area must emit natural gas emissions in an amount equal to or 
less than a low-bleed pneumatic controller, unless a high-bleed 
pneumatic controller is required for safety or process purposes. 
Section XVIII.C.2. requires that all pneumatic controllers at natural 
gas processing plants have a bleed rate of zero unless a pneumatic 
controller with a bleed rate greater than zero is necessary due to 
safety and process. Monitoring and recordkeeping requirements are set 
forth in Sections XVIII.D. and XVIII.E. and include inspection, 
maintenance, and records demonstrating compliance with emission 
reduction requirements in Section XVIII.C. Section XVIII.D.2. 
establishes additional monitoring and maintenance for pneumatic 
controllers with a natural gas bleed rate greater than zero.
    A detailed evaluation of Section XVIII is in the TSD for this 
action. We propose to find that the revisions to Section XVIII 
strengthen the SIP and meet CAA and RACT requirements. We therefore 
propose to approve the changes in Section XVIII.
2. May 8, 2019 Submittal
    The State's May 8, 2019 submittal contains typographical, 
grammatical, and formatting corrections to Reg. 7 Sections XII and 
XVIII that were not acted on in our February 24, 2021 action.\57\ The 
revisions do not change the substance of approved SIP provisions. We 
therefore propose to approve the revisions in Sections XII and XVIII.
---------------------------------------------------------------------------

    \57\ 86 FR 11125.
---------------------------------------------------------------------------

3. May 13, 2020 SIP Submittal
    The State's May 13, 2020 SIP submittal contains amendments to Reg. 
7, including a full reorganization of the regulation into Parts A-E. 
Table 4 show the current Reg. 7 numbering as related to the proposed 
Reg. 7 renumbering.

            Table 4--Current and Reorganized Reg. 7 Sections
------------------------------------------------------------------------
                                                   Reorganized Reg. 7
           Current Reg. 7 sections                      sections
------------------------------------------------------------------------
                                 Part A
------------------------------------------------------------------------
I. Applicability.............................  Part A, Section I.
II. General Provisions.......................  Part A, Section II.
Appendix A. Colorado Ozone Nonattainment or    Part A, Appendix A.
 Attainment Maintenance Areas.
------------------------------------------------------------------------
                                 Part B
------------------------------------------------------------------------
III. General Requirements for Storage and      Part B, Section I.
 Transfer of Volatile Organic Compounds.
IV. Storage of Highly Volatile Organic         Part B, Section II.
 Compounds.

[[Page 32665]]

 
V. Disposal of Volatile Organic Compounds....  Part B, Section III.
VI. Storage and Transfer of Petroleum Liquids  Part B, Section IV.
VII. Crude Oil...............................  Part B, Section V.
VIII. Petroleum Processing and Refining......  Part B, Section VI.
XV. Control of Volatile Organic Compound       Part B, Section VII.
 Leaks from Vapor Collection Systems and
 Vapor Control Systems Located at Gasoline
 Terminals, Gasoline Bulk Plants, and
 Gasoline Dispensing Facilities.
Appendix B. Criteria for Control of Vapors     Part B, Appendix B.
 from Gasoline Transfer to Storage Tanks.
Appendix C. Criteria for Control of Vapors     Part B, Appendix C.
 from Gasoline Transfer at Bulk Plants (Vapor
 Balance System).
Appendix E. Test Procedures for Annual         Removed (paragraphs B and
 Pressure/Vacuum Testing of Gasoline            E moved into section,
 Transport Tanks.                               and references replaced
                                                with EPA Method 27).
------------------------------------------------------------------------
                                 Part C
------------------------------------------------------------------------
IX. Surface Coating Operations...............  Part C, Section I.
X. Use of Cleaning Solvents..................  Part C, Section II.
XI. Use of Cutback Asphalt...................  Part C, Section III.
XIII. Graphic Arts and Printing..............  Part C, Section IV.
XIV. Pharmaceutical Synthesis................  Part C, Section V.
Appendix D. Minimum Cooling Capacities for     Part C, Appendix D.
 Refrigerated Freeboard Chillers on Vapor
 Degreasers.
Appendix F. Emission Limit Conversion          Part C, Appendix E.
 Procedure.
------------------------------------------------------------------------
                                 Part D
------------------------------------------------------------------------
XII. Volatile Organic Compound Emissions from  Part D, Section I.
 Oil and Gas Operations.
XVII. (State Only, except Section              Part D, Section II.
 XVII.E.3.a.,which was submitted as part of
 the Regional Haze SIP) Statewide Controls
 for Oil and Gas Operations and Natural Gas-
 Fired Reciprocating Internal Combustion
 Engines.
------------------------------------------------------------------------
                                 Part E
------------------------------------------------------------------------
XVI.A.-C. (natural gas fired reciprocating     Part E, Section I.
 internal combustion engines in the 8-hour
 ozone control area) and XVII.E. (new,
 modified, existing, and relocated natural
 gas fired reciprocating internal combustion
 engines).
XVI.D. Control of Emissions from Stationary    Part E, Section II.
 and Portable Combustion Equipment in the 8-
 Hour Ozone Control Area.
XIX. Control of Emissions from Specific Major  Part E, Section III.
 Sources of VOC and/or NOX in the 8-Hour
 Ozone Control Area.
XX. Control of Emissions from Breweries in     Part E, Section IV.
 the 8-Hour Ozone Control Area.
------------------------------------------------------------------------

    The State's May 13, 2020 SIP submittal also updates requirements 
for gasoline transport trucks, bulk terminals, and service stations; 
establishes a storage tank control threshold in lieu of the current 
system-wide control strategy; strengthens storage tank monitoring 
requirements; aligns related recordkeeping and reporting; and adds RACT 
requirements for major sources of VOC and/or NOx in the 8- hour Ozone 
Control Area. The submittal also includes clarifying revisions and 
typographical, grammatical and formatting corrections throughout Reg. 
7. We propose to approve the revisions to Reg. 7 included in Colorado's 
May 13, 2020 submittal as identified in Table 5. Below, we describe in 
detail Colorado's proposed revisions and the basis for our proposed 
approval of them. Additional analysis on how revisions meet RACT 
requirements can be found in the TSD for this action.
a. Part A
    The revisions add a new Part A heading, encompassing Sections I and 
II. Part A contains applicability and general provisions for Reg. 7. 
The revisions also include renumbering and updates to Parts and 
Sections referenced throughout Part A. The revisions do not change the 
substance of SIP approved rules. We therefore propose approval of the 
changes to Part A.
b. Part B
    The revisions add a new Part B heading for Sections I, II, III, IV, 
V, VI, VII (previously Reg. 7, Sections III through XV). and appendixes 
B and C. Part B regulates the storage, transfer, and disposal of VOC 
and petroleum liquids and petroleum processing and refining. The 
revisions to Reg. 7, Part B, Sections IV and VII update the gasoline 
transport truck testing and associated recordkeeping requirements and 
update and clarify the vapor system requirements. Revisions also 
include renumbering and updates to Parts and Sections referenced 
throughout Part B.
    Section IV (previously Section VI) regulates the storage and 
transfer of petroleum liquid, and Section VII (previously Section XV) 
regulates VOC leaks from vapor collection systems located at gasoline 
terminals, gasoline bulk plans, and gasoline dispensing facilities. 
Revisions to Sections IV and VII and the removal of the former Appendix 
E update requirements for gasoline transport trucks, bulk terminals, 
and service stations to align with current federal requirements for 
gasoline transport truck testing and vapor control systems. Section 
IV.A.2.j. adds a new definition for ``vapor collection system.'' The 
definition is clear, straightforward, accurate, and

[[Page 32666]]

consistent with the definition in Sections IV.D.1.b.(ii) and VII.A.3.c. 
Revisions made in Section IV.B.3. clarify that vapor collection systems 
must be leak-tight and properly maintained and operated.
    Section IV.D. regulates VOC leaks from gasoline transport trucks. 
Revision to Sections IV.D.2 and IV.D.3. replace the outdated vacuum-
pressure test in the CTG for Control of Volatile Organic Compound Leaks 
from Gasoline Tank Trucks and Vapor Collection Systems \58\ with the 
more current EPA Method 27.\59\ Federal standards in NSPS XX \60\, 
NESHAP R \61\, NESHAP BBBBBB \62\, and NESHAP CCCCCC \63\ reference the 
EPA's Method 27, Determination of Vapor Tightness of Gasoline Delivery 
Tank Using Pressure Vacuum Test, in contrast to the CTG's pressure-
vacuum test. The test values in Reg. 7 Section IV.D.4 were also updated 
and are based on the EPA's CTG and correspond to the EPA Method 27 test 
values in NSPS XX, NESHAP R, NESHAP BBBBBB, and NESHAP CCCCCC. 
Recordkeeping and certification requirements in Section IV.D.4. were 
updated to correspond to the EPA's Method 27 and federal standards.
---------------------------------------------------------------------------

    \58\ Control of Volatile Organic Compound Leaks from Gasoline 
Tank Trucks and Vapor Collection Systems, Appendix A, EPA-450/2-78-
051. Dec. 1978.
    \59\ See also 40 CFR 63.425(e).
    \60\ Standards of Performance for Bulk Gasoline Terminals (40 
CFR part 60, subpart XX (August 18, 1983, last revised December 19, 
2003)).
    \61\ National Emission Standards for Gasoline Distribution 
Facilities (Bulk Gasoline Terminals and Pipeline Breakout Stations) 
(40 CFR part 63 Subpart R (December 14, 1994, last revised April 6, 
2006)).
    \62\ National Emission Standards for Hazardous Air Pollutants 
for Source Category: Gasoline Distribution Bulk Terminals, Bulk 
Plants, and Pipeline Facilities (40 CFR part 63, subpart BBBBBB 
(January 10, 2008, last revised January 24, 2011)).
    \63\ National Emission Standards for Hazardous Air Pollutants 
for Source Category: Gasoline Dispensing Facilities (40 CFR part 63, 
subpart CCCCCC (January 10, 2008, last revised January 24, 2011)).
---------------------------------------------------------------------------

    Under CAA section 110(l), the EPA cannot approve a SIP revision 
that interferes with any requirement concerning attainment, reasonable 
further progress, or any other applicable requirement of the Act. We 
propose to find that the revisions to Section IV.D. comply with section 
110(l) because the revisions are limited to updating the pressure 
vacuum test and values to be consistent with more recent EPA 
regulations for gasoline tank trucks and vapor collection systems, and 
the changes do not weaken the SIP.
    We propose to find that the revisions in Part B are consistent with 
gasoline transport truck, terminal, and service station control and 
testing requirements of current NSPS and NESHAP standards and that 
approval of the submittal would comply with CAA Sections 110(l) and 
193. We therefore propose to approve the revisions in Part B.
c. Part C
    The revisions add a new Part C heading encompassing Sections I, II, 
III, IV, V (previously Reg. 7, Sections IX-XI, XIII, XIV) and 
appendixes D and E (formerly appendixes D and F). Part C regulates 
surface coating, solvents, asphalt, graphic arts and printing, and 
pharmaceuticals. The revisions also include renumbering and updates to 
Parts and Sections referenced throughout Part C, and adds a new 
categorical rule regulating VOC emissions from and establishing RACT 
for general solvent use in Section II.F.
    Section II.F. addresses VOC emissions from sources with a potential 
to emit 50 tons per year of VOC and with solvent use emissions greater 
than or equal to two tons per year in the DMNFR Area. Section II.F.3. 
sets forth work practice requirements including covering containers, 
proper disposal of solvent waste, and the use of good air pollution 
practices such as the use of low/no VOC solvent if possible, using only 
amounts needed, submerged fill pipes, closed loop systems, and 
maintaining operations to be leak free. Section II.F.4. requires 
operations that use solvents with uncontrolled actual VOC emissions 
greater than or equal to 25 tons per year to reduce emissions by 90%. 
Sections II.F.5. and 6. set forth monitoring and recordkeeping 
requirements. Records must be maintained for a minimum of two years. 
Sources subject to Section II.F.4. requirements are also subject to 
additional control requirements, monitoring, performance testing, and 
recordkeeping requirements for general solvent use operations.
    We propose to find that the provisions meet CAA and RACT 
requirements, and that they strengthen the SIP. We therefore propose to 
approve the changes in Part C.
d. Part D
    The revisions add a new Part D. heading for Sections I, II, and III 
(previously Reg. 7, Sections XII, XVII, and XVIII), and new Sections IV 
and V.\64\ Part D regulates oil and natural gas operations. The 
revisions also include renumbering and updates to Parts and Sections 
referenced throughout Part D, establishing a storage tank control 
threshold in lieu of the current system-wide control strategy, 
strengthening storage tank monitoring requirements, aligning related 
recordkeeping and reporting, and other SIP cleanup and strengthening 
measures.
---------------------------------------------------------------------------

    \64\ Parts of the submission, including all of new Sections IV 
and V, are State Only requirements. We therefore will not be acting 
on these Sections. The State Only provisions are excluded from the 
list of provisions that we are acting on in Table 5.
---------------------------------------------------------------------------

(i) Section I.A.
    Section I.A. contains applicability provisions for Part D. The 
revisions to Section I.A. streamline and clarify sources subject to 
Part D and remove the exemption associated with the system-wide control 
program for owners or operators of condensate tanks with total actual 
uncontrolled VOC emissions less than 30 tpy (previously Section 
XII.A.7.).
(ii) Sections I.B. and I.C.
    Section I.B. contains definitions applicable to Part D. A new 
definition for ``commencement of operation'' was added for consistency 
with Regulation Number 3 and for clarity as to the applicability of 
other control requirements. New definitions for ``intermediate 
hydrocarbon liquid,'' ``produced water,'' ``storage tank,'' and 
``storage vessel'' were also added. The definitions are clear, 
straightforward, accurate.
    Section I.C. contains general provisions for Part D. Section I.C.2. 
specifies how operators must calculate emissions and emission 
reductions to demonstrate compliance with control requirements. The 
revisions in Section I.C.2.a.(iv) expand current provisions to tanks 
storing produced water or hydrocarbon liquids other than condensate.
(iii) Section I.D.
    Section I.D. contains provisions for storage tank emissions 
controls. In 2004 the Commission adopted the initial system-wide 
control strategy, which required operators to reduce emissions from 
their system of condensate tanks. The ``system'' was composed of 
condensate tanks with uncontrolled actual VOC emissions equal to or 
greater than two tpy, and allowed operators to decide which tanks to 
control if emissions from the ``system'' were reduced by specified 
percentages. The revisions in Section I.D. replace the system-wide 
control strategy with an individual storage tank control strategy in 
Section I.D.3. Operators in the DMNFR Area were required to install 
controls on storage tanks with uncontrolled actual VOC emissions equal 
to or greater than four tpy by May 1, 2020. The control requirements in 
Section I.D. were expanded to include crude oil and produced water 
tanks. According to the Division, this will

[[Page 32667]]

result in more tanks being controlled.\65\ Section I.D.3.a.(i) requires 
that storage tanks with uncontrolled actual emissions of VOC equal to 
or greater than four tons per year collect and control emissions from 
each storage tank by routing emissions to and operating air pollution 
control equipment that achieves a VOC control efficiency of 95%; 
combustion devices must have a design destruction efficiency of at 
least 98% for VOC unless authorized by permit before March 1, 2020. 
Section I.D.3.c. requires that storage tanks below the four tpy 
threshold that increase emissions above the threshold must be in 
compliance within 60 days of the first date of the month in which the 
threshold was exceeded. The Commission has determined that the four tpy 
threshold and implementation timetable is cost-effective, technically 
feasible, and will ensure no backsliding as provided for in the Clean 
Air Act, Section 110(l).\66\
---------------------------------------------------------------------------

    \65\ See pp. 592-593 of the May 13, 2020 submittal.
    \66\ See p. 591 of the May 13, 2020 submission.
---------------------------------------------------------------------------

    Colorado also submitted a provision for inclusion in the SIP that 
was previously state-only. Section I.D.2.a. requires that that 
operators of newly constructed tanks employ controls during the first 
90 days after the date of first production. The provision is proposed 
for inclusion in the SIP to avoid confusion as to whether compliance 
with the requirement can be considered a limitation upon a source's 
potential to emit for purposes of permitting.
(iv) Section I.E.
    Section I.E. contains provisions for monitoring of storage tanks 
and air pollution control equipment. Section I.E. was revised to apply 
the monitoring requirements for all storage tanks controlled pursuant 
to Section I.D., which will ensure monitoring of condensate tanks, 
crude oil, and produced water tanks on a weekly basis per Section 
I.E.2.c. The required inspections have also been updated to include 
elements that can impact the performance of well production facility 
equipment and reduce emissions including checking that burner trays are 
not visibly clogged, that pressure relief valves are properly sealed, 
and that vent lines are closed. Inspection documentation requirements 
in former Section XII.E.3. were removed and moved to Section 
I.F.2.c.(iii) in order to condense all recordkeeping requirements in 
Section I.F.
(v) Section I.F.
    Section I.F. contains provisions for storage tank recordkeeping and 
reporting. As a result of replacing the system-wide control strategy 
with the fixed control threshold in Section I.D., recordkeeping and 
reporting requirements for demonstrating compliance with Section I.D. 
were revised in Section I.F. Operators subject to the system-wide 
control strategy were given until August 31, 2020, to submit the report 
for the time period in 2020 during which the system-wide control 
strategy remained effective (i.e. January 1-April 30, 2020). Section 
I.F.2 contains the recordkeeping and reporting scheme for the tanks 
subject to the new four tpy control threshold provision. Under Sections 
I.F.2. and I.F.3., owners or operators of storage tanks subject to 
Section I.D.3. must maintain records and submit annual reports 
including information regarding inspections, calendar monthly VOC 
emissions, emission factors used, and the control efficiency of air 
pollution control equipment. Reports must be retained for a minimum of 
five years.
(vi) Section I.L.
    Section I.L. contains provisions for the DMNFR Area leak detection 
and repair program. Sections I.L.2.a. and I.L.2.b. revised language 
clarifies that applicability for leak inspections at well production 
facilities are based on rolling twelve-month emission totals and not a 
calendar year basis.
(vii) Section II
    Section II contains statewide controls for oil and gas operations. 
The majority of Section II consists of State Only requirements. 
However, the Commission submitted previous State Only revisions for 
inclusion in the SIP to Section II.C.1.b.(ii), which requires that 
operators of newly constructed tanks employ controls within 90 days of 
commencement of operation. Previous State Only requirements in Section 
II.G. were also submitted for inclusion in Colorado's SIP. The 
provisions require control of emissions coming off a separator after a 
well is newly constructed, hydraulically fractured, or recompleted. 
These emissions must be routed to a gas gathering line or controlled by 
air pollution control equipment. The provisions were submitted for 
inclusion in the SIP to clarify permitting compliance requirements in 
Reg. 3.
    We propose to find that the revisions to Part D meet CAA and RACT 
requirements, and that they strengthen the SIP. We therefore propose to 
approve the changes in Part C.
e. Part E
    The revisions add a new Part E heading for Sections I, II, III, and 
IV (previously Reg 7, Sections XVI, XIX, and XX). Part E regulates 
emissions from combustion equipment at major sources of RACT. The 
revisions also include renumbering and updates to Parts and Sections 
referenced throughout Part E, add RACT requirements in Colorado's ozone 
SIP for 50 tpy major sources of VOC and/or NO<INF>X</INF>, and other 
cleanup and strengthening measures.\67\
---------------------------------------------------------------------------

    \67\ The revisions to Sections II.A.1.b., II.A.4.a.(iii) and 
(iv), II.A.6.a.(ii), and II.A.6.b.(viii)(B) include the placeholder 
language [EFFECTIVE DATE OF THE RECLASSIFICATION] because the 
Commission approved the revisions before the EPA finalized 
reclassification of the DMNFR Area to Serious. The EPA finalized its 
reclassification of the Area on December 26, 2019. See Final rule, 
Finding of Failure To Attain and Reclassification of Denver Area for 
the 2008 Ozone National Ambient Air Quality Standard, 84 FR 70897.
---------------------------------------------------------------------------

(i) Section II
    Section II provisions control emissions from stationary and 
portable combustion equipment in the DMNFR area. Section II.A.1.b. 
expands the applicability of Section II requirements to stationary 
combustion equipment at major sources of NO<INF>X</INF> as of January 
27, 2020. New definitions were added in Section II.A.3. for ``ceramic 
kiln,'' ``dryer,'' and ``furnace'' to support the expanded combustion 
adjustment requirements in Section II.A.6. The definitions are clear, 
straightforward, and accurate.
    Owners or operators of combustion equipment specified in Section 
II.A.1.b. must comply with emission limits in Section II.A.4. by July 
20, 2021. This date is consistent with the EPA's implementation 
deadline for RACT measures not tied to attainment.\68\ New Sections 
II.A.4.a.(iii) expands emission limits requirements for boilers over 
100 MMBtu/hr larger boilers and Section II.A.4.a.(iv) adds emission 
limits for boilers between 50 and 100 MMBtu/hr located at sources 
greater than or equal to 50 tpy of NO<INF>X</INF>. Applicability of 
combustion process adjustment requirements in Section II.A.6. was 
expanded to include individual pieces of combustion equipment at major 
sources of NO<INF>X</INF> under a Serious classification. The 
requirements of Section II.A.6.a.(ii) apply to boilers, duct burners, 
process heaters, stationary combustion turbines, stationary

[[Page 32668]]

reciprocating internal combustion engines, dryers, furnaces, and 
ceramic kilns that have uncontrolled actual NO<INF>X</INF> emissions 
equal to or greater than five tpy that existed at major sources of 
NO<INF>X</INF> as January 27, 2020. Sections II.A.6.(v)-(vii) expand 
combustion process adjustment requirements to dryers, furnaces, and 
ceramic kilns. Sections II.A.6.b.(viii)(A)-(C) clarify and expand 
combustion adjustment frequency requirements, including dates for 
initial combustion process adjustments.
---------------------------------------------------------------------------

    \68\ Final Rule, Finding of Failure To Attain and 
Reclassification of Denver Area for the 2008 Ozone National Ambient 
Air Quality Standard, 84 FR 70897, 70900 (Dec. 26, 2019).
---------------------------------------------------------------------------

    We propose to find that the revisions to Section II are consistent 
with CAA requirements, and that they strengthen the SIP.
(ii) Section III
    Section III provisions control emissions from specific major 
sources of VOC and/or NO<INF>X</INF> in the DMNFR area. Section 
III.B.1. establishes emission limits and associated monitoring, 
recordkeeping, and reporting (MRR) requirements for stationary internal 
combustion engines at certain major sources to meet RACT. Section 
III.B.2. sets forth flare requirements and Section III.B.3. establishes 
MRR requirements for specific emission points at certain major sources 
to meet RACT. Section III.B.4. requires certain major sources to submit 
RACT analyses to the Division. We propose to find that the revisions to 
Sections III.B.1. through 4. strengthen the SIP and meet CAA 
requirements. We also propose to find that Sections III.B.1. through 2. 
establishes RACT requirements for certain major sources by 
incorporating federal regulations.
    We propose to find that the revisions to Part E are consistent with 
CAA requirements, and that they strengthen the SIP. We therefore 
propose to approve the changes in Part E.

VII. Proposed Action

    For the reasons expressed above, the EPA proposes to approve 
revisions to Sections II, XII, and XVIII of Reg. 7 from the State's May 
14, 2018 and May 8, 2019 submittals and Parts A through E from the 
State's May 13, 2020 submission as shown in Table 5, except for those 
revisions we are not acting on as represented in Table 6. We are 
proposing to approve Colorado's determination that the above rules 
constitute RACT for the specific categories addressed in Tables 2 and 
3.
    A comprehensive summary of the revisions in Colorado's Reg. 7 
organized by the EPA's proposed rule action, reason for proposed ``no 
action'' and submittal date are provided in Tables 5 and 6.

 Table 5--List of Colorado Revisions to Reg. 7 That the EPA Proposes To
                                 Approve
------------------------------------------------------------------------
     Revised sections in May 14, 2018, May 8, 2019 and May 13, 2020
                    submittals proposed for approval
-------------------------------------------------------------------------
May 14, 2018 Submittal:
    II.B, XII.A.2, XII.B.1.-XII.B.3., XII.B.6-XII.B.13, XII.B.16-
     XII.B.21., XII.B.25., XII.C.1.d.-XII.C.1.e., XII.C.1.e.(iv),
     XII.D., XII.F., XII.F.3.a.(i)-XII.F.3.a.(x), XII.F.5., XII.G.,
     XII.G.1., XII.G.3., XII.G.4., XII.H.3., XII.H.6.a., XII.I., XII.J.,
     XII.J.1, XII.J.1.a.-j., XII.J.2., XII.J.2.a.-e., XII.K., XII.K.1.,
     XII.K.2., XII.K.2.a.-h(iv), XII.K.3., XII.K.3.a., XII.K.a.(i)-(vi),
     XII.K.4., XII.K.5., XII.L., XII.L.1., XII.L.1.a.-b., XII.L.2.,
     XII.L.2.a.-d., XII.L.3., XII.L.3.a.-c., XII.L.4., XII.L.4.a.-e.,
     XII.L.5., XII.L.5.a.-c., XII.L.6., XII.L.6.a.-i., XII.L.7.,
     XII.L.7.a.-g., XII.L.8., XII.L.8.a., XII.L.8.a.(i)-(ii),
     XII.L.8.a.(ii)(A)-(I), XII.L.8.a.(iii), XII.L.8.a.(iv),
     XII.L.8.a.(v), XVIII, XVIII.B.1..-B.3., XVIII.B.5.-11., XVIII.C.-
     XVIII.C.2.c.(ii), XVIII.D.-XVIII.D.2.b., and XVIII.E.-XVIII.E.2.c.
May 8, 2019 Submittal:
    XII.B.12., XII.B.13., XII.B.20., XIII.G.3., XII.J.1.j., XII.J.2.e.,
     XII.K.5., XVIII.B.1., XVIII.B.5., XVIII.B.7.-9., and XVIII.D.1.b.
May 13, 2020 Submittal:
    Outline of Regulation, PART A, I.A.1.c., I.B.1.c., I.B.2.h., II.B.,
     PART B, I.-I.C., II.--B., III.-III.B., IV.- IV.D.4.e., V.-V.C., VI.-
      VI.C.4.c.(ii), VII.- VII.B.2.b., Appendix B, V., VIII., Appendix
     C, PART C, I.- I.O.5.a.(v), II.- II.F.6.j., III.- III.B.3.b., IV-
     IV.B.5.c.(iii)(B), V.-V.C.1., Appendix D (renumbering), PART D, I.-
     I.B.27., I.B.29.-I.C.e., I.C.1.e.(iii)-(iv), I.C.2.- I.C.2.a.(v),
     I.D.- I.D.3.a.(i), I.D.3.b.- I.D.3.b.(iii), I.D.3.b.(v),
     I.D.3.b.(vii), I.D.3.b.(ix), I.D.4.- I.E.1.a., I.E.2.-
     I.E.2.c.(ii), I.E.2.c.(iv)- I.E.2.c.(viii), I.F.-I.F.1.d.,
     .I.F.1.g.-I.F.1.g.(xii), I.F.1.h.- I.F.2.a., I.F.2.c.-
     I.F.2.c.(vi), I.F.3., I.F.3.a., I.F.3.c.- I.F.3.c.(i)(C), I.G.-
     I.H.1., I.H.3.-I.L.8.a.(v)., II.C., II.C.1., II.C.1.b.(ii)-(B),
     II.F, III.-III.B.3., III.B.5., III.B.7.-III.C.2.c.(ii), III.D.-
     III.D.2.b., III.D.3.b., III.E.-III.E.2.c., PART E, I.-I.D., I.D.3.-
     I.D.3.a.(ii), II.-II.A.4.b., II.A.4.b.(ii)-II.A.4.c., II.A.4.e.-
     II.A.8.b.(i), III.-III.B.4.n., IV.-IV.A.7.c.
------------------------------------------------------------------------


 Table 6--List of Colorado Revisions to Reg. 7 That the EPA Is Proposing
                          To Take No Action on
------------------------------------------------------------------------
                                                Reason for proposed ``no
               Revised sections                         action''
------------------------------------------------------------------------
May 14, 2018 Submittal:
    XII.A.1., XII.A.1.c., XII.A.1.d.(ii),      Superseded by May 13,
     XII.A.2.-7., XII.B., XII.B.4.-5.,          2020 submittal.
     XII.B.12.-14., XII.B.22.-24., XII.C.,
     XII.C.1.a., XII.C.1.e.(i)-(ii),
     XII.C.1.f.-(ii), XII.D., XII.D.1.,
     XII.D.2.a.-(i), XII.D.2.a.(vi)-(vii),
     XII.E., XII.E.2.c., XII.F., XII.F.4..
May 14, 2018 Submittal:
    XVIII.B.4 \69\...........................  State requested this be
                                                ``state only''
                                                definition.\70\
May 13, 2020 submittal:
    II.A.4.d.-(i)............................  Provision not previously
                                                approved in the SIP.
------------------------------------------------------------------------

VIII. Incorporation by Reference

    In this document, the EPA is proposing to include regulatory text 
in an EPA final rule that includes incorporation by reference. In 
accordance with requirements of 1 CFR 51.5, the EPA is proposing to 
incorporate by reference Colorado AQCC Regulation 7 pertaining to the 
control of ozone via ozone precursors and control of hydrocarbons vial 
oil and gas emissions discussed in section VI of this preamble. The EPA 
has made, and will continue to make, these materials generally 
available through www.regulations.gov and at the EPA Region 8 Office 
(please contact the person identified in the FOR FURTHER

[[Page 32669]]

INFORMATION CONTACT section of this preamble for more information).
---------------------------------------------------------------------------

    \69\ Revised Section III.B.4.
    \70\ See March 1, 2021 email and attached letter from Colorado 
on ``Revised Pneumatics SIP Revisions Justification'' and May 3, 
2021 email from Leah Martland, Colorado Air Pollution Control 
Division (contained within the docket). The definition for 
``enhanced response'' is in reference to the State Only pneumatics 
find and fix program and thus not applicable to SIP provisions.
---------------------------------------------------------------------------

IX. 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:
    <bullet> 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);
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> 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.);
    <bullet> 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);
    <bullet> Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
    <bullet> 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.
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where the EPA or an Indian tribe 
has demonstrated that a tribe has jurisdiction. 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).
    Executive Order 12898 (Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
February 16, 1994) directs federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. We 
are proposing to approve state rules as meeting the CAA standard for 
RACT, which EPA has defined as the lowest emission limitation that a 
particular source is capable of meeting by the application of control 
technology that is reasonably available considering technological and 
economic feasibility. Accordingly, we propose to determine that this 
rule, if finalized, will not have disproportionately high or adverse 
human health or environmental effects on minority or low-income 
populations.

List of Subjects in 40 CFR Part 52

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

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

    Dated: June 11, 2021.
Debra H. Thomas,
Acting Regional Administrator, Region 8.
[FR Doc. 2021-12875 Filed 6-21-21; 8:45 am]
BILLING CODE 6560-50-P


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