2020-20099. 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

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing approval and conditional approval of State Implementation Plan (SIP) revisions submitted by the State of Colorado on May 31, 2017, May 14, 2018, and May 10, 2019. 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 reasonably available control technology (RACT) SIP obligations for Moderate 2008 ozone nonattainment areas; add incorporation by reference dates to rules and reference methods; and make typographical, grammatical, and formatting corrections. Also, in this action, the EPA is proposing to correct a July 3, 2018 final rule pertaining to Colorado's SIP. In that action, we inadvertently excluded regulatory text corresponding to “incorporation by reference” (IBR) materials for graphic arts and printing revisions to Reg. 7, Section XIII (adopted November 17, 2016). The EPA is taking this action pursuant to the Clean Air Act (CAA).

DATES:

Written comments must be received on or before November 5, 2020.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R08-OAR-2020-0114, 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, Telephone number: [phone], email address: [e-mail].

SUPPLEMENTARY INFORMATION:

Throughout this document wherever “we,” “us,” or “our” is used, we mean the EPA.

I. What action is the Agency taking?

As explained below, the EPA is proposing to approve various revisions to the Colorado SIP that were submitted to the EPA on May 31, 2017, May 14, 2018, and May 10, 2019. In particular, we propose to approve certain area source rules to meet the 2008 8-hour ozone national ambient air quality standards (NAAQS) RACT requirements for Moderate nonattainment areas that were not acted on in our July 3, 2018 rulemaking approving the State's attainment demonstration and various SIP elements.^[1] We are also proposing to approve into the SIP the submitted revisions to Colorado's Reg. 7 that we have not previously acted on, except for Sections XII and XVIII (from the May 2018 submittal) and Sections XVI.D.4.b.(i) and XVI.D.4.d. (from the two May 2019 submittals), which we will be acting on at a later date (see Tables 4, 5 and 6). Finally, we propose to approve IBR material submitted in May 2017 but inadvertently excluded from our July 3, 2018 action.

The specific bases for our proposed actions and 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-2020-0114.

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.^[2] 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.^[3]

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.^[4] With that rulemaking, the Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado area (Denver or DMNFR Area) area was designated nonattainment and classified as Marginal.^[5] 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.^[6] 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.^[7]

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.^[8] Colorado submitted SIP revisions to the EPA on May 31, 2017 to meet the Denver Area's requirements under the Moderate classification.^[9] 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.^[10]

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,^[11] 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,^[12] and the EPA later approved revisions to Reg. 7, Sections I through XI and Sections XIII through XVI.^[13] The EPA also approved Reg. 7 revisions to control emissions from rich-burn reciprocating internal combustion engines in Section XVII.E.3.a.^[14]

Most recently, in 2018 the EPA approved Reg. 7 revisions in Sections XII (emission control requirements for volatile organic compounds (VOCs) from oil and gas operations), and XIII (emission control requirements for VOC emissions from graphic art and printing processes),^[15] as well as non-substantive revisions to numerous other parts of the regulation.^[16]

III. Summary of the State's SIP Submittals

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

May 31, 2017 Submittal

This submittal contains revisions to Reg. 7 that the EPA has not yet acted on. These include Sections X (Use of Cleaning Solvents), 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 nitrogen oxides (NO_X) in the 8-hour Ozone Control Area). In addition, this submittal contains graphic arts and printing revisions to Section XIII. In our final rule published in the Federal Register on July 3, 2018, we inadvertently did not include regulatory text and corresponding IBR materials for our approval to graphic arts and printing revisions to Reg. 7, Section XIII (adopted November 17, 2016).^[17] The EPA is proposing to correct this error with today's action. The IBR material for our July 3, 2018 action is in the docket for this action.

May 14, 2018 Submittal

This submittal contains amendments to Reg. 7 Sections XII and XVIII to meet RACT for oil and gas sources covered by EPA's 2016 Oil and Gas Control Techniques Guideline (CTG). The submittal also includes clarifying revisions and typographical, grammatical, and formatting corrections throughout Reg. 7.

May 10, 2019 Submittals

On this date the State submitted two SIP revisions. One submittal contains amendments to Reg. 7 that establish categorical RACT requirements for major sources of NO_X in the DMNFR Area. Specifically, on July 19, 2018 the AQCC adopted RACT requirements in Section XVI.D. for boilers, stationary combustion turbines, lightweight aggregate kilns, glass melting furnaces, and compression ignition reciprocating internal combustion engines (“RICE”) (collectively referred to as “stationary combustion equipment”) located at major sources of NO_X.^[18]

The other submittal contains amendments to Reg. 7 that were adopted by the AQCC on November 15, 2018. The revisions include RACT requirements in Section XX for brewing-related activities at major sources of VOC, and RACT requirements in Section IX for wood furniture surface coating operations. The submittal also includes revisions to IBR dates to rules and reference methods in Sections II, VI, VIII, IX, X, XII, XIII, XVI and XVII. Lastly, the submittal contains SIP cleanup revisions, including removal of a one-time RACT reporting requirement in Section I, adds a surface coating work practice in Section IX, and revises an exemption in the industrial cleaning solvent requirements in Section X. Typographical, grammatical, and formatting corrections were also made.

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.^[19] For the May 31, 2017 submittal, the AQCC provided notice in the Colorado Register on July 29 and August 29, 2016, and held a public hearing on the SIP revisions on November 17, 2016. The Commission adopted the SIP revisions on November 17, 2016. The SIP revisions became state-effective on January 14, 2017.

For the May 14, 2018 submittal, the AQCC provided notice in the Colorado Register on July 22, 2017 and held a public hearing on the revisions on October 19 and 20, 2017. The Commission adopted the SIP revisions on November 16, 2017. The SIP revisions became state-effective on December 20, 2017.

For the May 10, 2019 submittal (RACT for combustion sources), the AQCC provided notice in the Colorado Register on April 21, 2018 and held a public hearing on the revisions on July 19, 2018. The Commission adopted the SIP revisions on July 19, 2018. The SIP revisions became state-effective on September 14, 2018.

For the May 10, 2019 submittal (RACT for brewing related activities and wood furniture surface coating operations), 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.

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 “provide for the implementation of all reasonably available control measures as expeditiously as practicable (including such reductions in emissions from existing sources in the area as may be obtained through the adoption, at a minimum, of reasonably available control technology).” ^[20] 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.^[21] The CAA amendments of 1990 introduced the requirement for existing major stationary sources of NO_X in nonattainment areas to install and operate NO_X RACT. Specifically, section 182(b)(2) of the CAA requires states to adopt RACT for all major sources of VOC not covered by an existing CTG in ozone nonattainment areas, and section 182(f) requires the RACT provisions for major stationary sources of NO_X.

The EPA provides guidance concerning what types of controls can constitute RACT for a given source category by issuing CTG and Alternative Control Techniques (ACT) documents.^[22] 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.^[23]

For a Moderate nonattainment area, a major stationary source is one that emits, or has the potential to emit, 100 tons per year (tpy) or more of VOCs or NO_X.^[24] RACT can be adopted in the form of emission limitations or “work practice standards or other operation and maintenance requirements,” as appropriate.^[25] In assessing RACT requirements under the Moderate classification, the Colorado Air Pollution Control Division (Division) identified 51 major sources in the DMNFR Area, operated by 32 companies.

In November 2016, the Commission determined that some major sources and CTG VOC source categories were adequately addressed under existing SIP requirements. The Commission also adopted new requirements for some major sources and CTG VOC source categories. In July 2018, the Commission adopted categorical RACT requirements for combustion equipment at major sources that the Commission had determined in 2016 were not addressed by SIP RACT requirements. In November 2018, the Commission adopted SIP requirements to include provisions that implement RACT for major sources of VOC and NO_X and for all CTG VOC source categories in the DMNFR ozone nonattainment area (NAA). Specifically, the Commission adopted categorical RACT requirements for combustion equipment at major sources, major source breweries and wood furniture manufacturing, and addressed EPA concerns with industrial cleaning solvent and metal furniture surface coating requirements.^[26]

B. Evaluation

As part of its May 31, 2017 and May 10, 2019 submittals, the Division conducted RACT analyses to demonstrate that the RACT requirements for CTG and major sources in the DMNFR 2008 8-hour ozone NAA have been fulfilled. The Division conducted these RACT analyses for VOC and NO_X by listing the state regulation that implements or exceeds RACT requirements for each CTG 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 and rules developed by other state and local agencies. A summary of our proposed action with respect to each RACT category follows.

Category	Proposed action	Location of RACT demonstration
Aerospace	Conditional approval of the State's negative declaration that there are no sources in the DMNFR Area subject to the aerospace CTG	n/a.
Certain Major sources of NOX and VOC	Approval	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 (p. 2990-3273 of May 10, 2017 submittal).
Combustion equipment at major sources	Approval	Categorical Reasonably Available Control Technology Review for Boilers, Turbines, Engines, Glass Melt Furnaces and Aggregate Kilns and Major NOX Sources in the Denver Metro/North Front Range Ozone Nonattainment Area, July 2018, document set 25 (contained within the May 31, 2019 submittal for combustion equipment).
Industrial cleaning solvents	Approval	p. 1116 of the May 31, 2017 submittal and p. 4 of the Statement of Basis, document set 18 (contained within the May 10, 2019 submittal for RACT for brewing related activities and wood furniture surface coating operations).
Major Source Breweries	Approval	State of Colorado Categorical Reasonable Available Control Technology Review for Brewing and Wood Furniture Surface Coating TSD, October 30, 2018, p. 5, document set 21 (contained within the May 10, 2019 submittal).
Metal furniture coatings	Approval	p. 1126 of the May 31, 2017 submittal.
Wood furniture manufacturing	Approval	pp. 1115 and 1135 of the May 31, 2017 submittal, and p. 24 of the State of Colorado Categorical Reasonable Available Control Technology Review for Brewing and Wood Furniture Surface Coating TSD, October 30, 2018, document set 21 (contained within the May 10, 2019 submittal).
Cited materials are contained within the docket for this action.

In our July 3, 2018 rulemaking, we approved Colorado's demonstration of RACT for certain VOC CTG sources ^[27] for the 2008 8-hour ozone standard. Today we are taking action on the RACT demonstrations for certain additional VOC CTG, non-CTG VOC, and NO_X sources and categories. We have reviewed Colorado's new and revised VOC and NO_X rules for the source categories covered by the CTGs, and for major sources of non-CTG VOC and NO_X 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 control measures, definitions, recordkeeping, and test methods in these CTGs and the CAA, and that they satisfy CAA RACT requirements for the categories in question.^[28]

1. RACT for CTG Sources

Table 1 contains a list of CTG source categories, EPA reference documents, and the corresponding sections of Reg. 7 that fulfill the applicable RACT requirements for EPA-issued CTGs.^[29] Colorado's Reg. 7 contains SIP-approved ^[30] and submitted revisions (see Section IV of this document); we propose to find that these revisions meet RACT requirements for the source categories listed in Table 1.

Table 1—Source Categories, EPA CTG Reference Documents, and Corresponding Sections of Reg. 7 Fulfilling RACT

Source category in DMNFR Area	CTG reference document	Date of CTG	Reg. 7 sections fulfilling RACT
Metal Furniture Coatings 31	Control Techniques Guidelines for Metal Furniture Coatings	2007	Sections V and IX (already SIP approved except XI.A.9.a.(ii) proposed for approval in this action).
Wood Furniture Manufacturing Operations 32	Control of Volatile Organic Compound Emissions from Wood Furniture Manufacturing Operations	1996	Sections V (already SIP approved) and IX.O (proposed for approval in this action).
Industrial Cleaning Solvents 33	Control Techniques Guidelines for Industrial Cleaning Solvents	2006	Sections V (already SIP approved) and X (proposed for approval in this action).
Aerospace 34	Control of Volatile Organic Compound Emissions from Coating Operations at Aerospace Manufacturing and Rework Operations	1997	No sources above the CTG applicability threshold in the DMNFR Area (negative declaration proposed for conditional approval in this action).

We have reviewed the emission limitations and control requirements for the above source categories and compared them against the EPA's CTG documents and available technical information in CTG dockets and regional RACT determinations. The EPA has also evaluated the submitted rules ^[35] and has determined that they are consistent with the CAA, EPA regulations, and EPA policy. 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 source categories identified in Table 1 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 Appendix 6-F of the May 31, 2017 submittal, Colorado identified a list of major non-CTG VOC and NO_X sources in the DMNFR Area. The State reviewed its point source inventory to verify that major sources of VOC and NO_X emissions in the NAA are subject to requirements that meet or exceed RACT. For major VOC and NO_X sources subject to NAA 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_X at a major NO_X source, as reported on source Air Pollutant Emission Notices, were evaluated. We have reviewed the State's May 31, 2017 submittal and find its approach to including these sources in the inventory acceptable.

On November 17, 2016, to satisfy the Moderate RACT SIP requirement to establish RACT for all existing major sources of VOC and/or NO_X in the DMNFR Area, the Commission incorporated by reference several New Source Performance Standards (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations.^[36] The Division also developed the stationary combustion equipment and brewery categorical RACT standards, based on a detailed review of the information provided by owners and operators of major NO_X 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 2 contains a list of non-CTG source category EPA reference documents and the corresponding sections of Reg. 7 that are proposed for approval in this action to fulfill RACT requirements (see Section IV of this document).^[37]

Table 2—Source Categories, EPA Reference Documents, and Corresponding Sections of Reg. 7 Proposed for Approval To Fulfill RACT

Source category in the DMNFR Area 38	EPA reference documents (if applicable)	Date of ACT	Reg. 7 sections fulfilling RACT
Stationary Internal Combustion Engines 39	NOX Emissions from Stationary Internal Combustion Engines (EPA-453/R-93-032)	July 1993, Updated September 2000	Applicable provisions in XVI.D. and XIX.A. (proposed for approval in this action).
Commercial & Institutional Boilers 40	NOX Emissions from Industrial, Commercial and Institutional Boilers (EPA-453/R-94-022)	March 1994	Applicable provisions in XVI.D. (proposed for approval in this action).
Stationary Combustion Turbines 41	NOX Emissions from Stationary Gas Turbines (EPA-453/R-93-007)	January 1993	Applicable provisions in XVI.D. (proposed for approval in this action, except XVI.D.4.b.(i) which will be acted on at a later date).
Utility Boilers 42	NOX Emissions from Utility Boilers (EPA-453/R-94-023)	March 1994	Applicable provisions in XVI.D. (proposed for approval in this action).
Cement Manufacturing 43	NOX Emissions from Cement Manufacturing (EPA-453/R-94-004) and NOX Control Technologies for the Cement Industry: Final Report (EPA-457/R-00-002).	March 1994/September 2000	XIX.B. (proposed for approval in this action).
Landfill Gas Flares 44			XIX.C. (proposed for approval in this action).
Brewing Operations 45			XX. (proposed for approval in this action).

 

We have reviewed the emission limitations and control requirements for the source categories in Table 2 and compared them against EPA's ACT documents, available technical information, and guidelines. The EPA has also evaluated the submitted rules ^[46] and has determined that they are consistent with the CAA, EPA regulations, and EPA policy. 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, with the noted exceptions, the control requirements for the source categories identified in Table 2 are RACT for all affected sources in the DMNFR Area under the 2008 8-hour ozone NAAQS. We also propose to find that for VOC RACT requirements at major non-CTG VOC sources, Colorado has RACT-level controls in place for the DMNFR Area under the 2008 8-hour ozone standard. We are not finalizing our RACT determination for major sources of NO_X in this document because we have requested additional analyses from Colorado for older turbines and process heaters.

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

We evaluated Colorado's May 31, 2017, May 14, 2018, and May 10, 2019 submittals regarding revisions to the State's Reg. 7 to meet RACT requirements for various source categories. Revisions to Reg. 7 include emission control requirements for surface coating operations, use of cleaning solvents, oil and gas operations, stationary and portable combustion equipment, major sources of VOC and/or NO_X in the ozone NAA, and breweries. The revisions establish RACT requirements for certain CTG categories and emission points at major sources of VOC and NO_X in the DMNFR Area. Reg. 7 revisions also add incorporation by reference dates to rules and reference methods; 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 EPA 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 31, 2017 SIP Submittal

The State's May 31, 2017 SIP submittal contains amendments to Reg. 7 that were not acted on in our July 3, 2018 rulemaking.^[47] We propose to approve the changes included in Colorado's May 31, 2017 submittal, as identified in Table 4.^[48] Below, we describe in detail Colorado's proposed revisions and the basis for our proposed approval of them.

a. Section X

Section X regulates VOC emissions from and establishes RACT for the use of cleaning solvents. Changes to Sections X, X.A.1, X.A.2.b.- j., X.B.1.d.(ii), and X.D.1.a.(i) include clarification of the applicability of Section X, addition of an effective date for Section X requirements, addition of definitions for terms used in industrial cleaning solvent operations, and minor clerical ^[49] revisions that do not affect the substance of the requirements.

Section X.E. addresses VOC emissions from industrial cleaning solvent operations. Section X.E.1 sets forth control requirements for owners and operators of industrial cleaning solvent operations with uncontrolled and non-exempt VOC emissions of three tons per year or more. These owners and operators must limit the VOC content of cleaning solvents to less than or equal to 0.42 lb of VOC/gal (50 grams VOC/liter), limit the composite partial vapor pressure of cleaning solvent to 8 millimeters of mercury (mmHg) at 20 degrees Celsius (68 degrees Fahrenheit), and reduce VOC emissions with an emission control system having a control efficiency of 90% or greater. Section X.E.2. adds work practice requirements to reduce VOC emissions from fugitive sources, while Section X.E.3. contains monitoring, recordkeeping, and reporting requirements to demonstrate compliance with the control requirements in Section X.E. Section X.E.4.contains exemptions from the requirements in X.E. We are proposing to approve the exemptions in X.E.4., X.E.4.b., X.E.4.b.(i)-(xi), X.E.4.c., and X.E.4.c.(i)-(ii) from the May 31, 2017 SIP submittal. All other exemptions in Section X.E. have been superseded by the May 10, 2019 submittal.

We propose to find that the provisions are consistent with CAA requirements and CTGs, and that they strengthen the SIP, and therefore we propose to approve the changes in Section X.

b. Section XVI

Section XVI specifies emission control requirements for stationary and portable combustion equipment. Section XVI.D.^[50] adds a combustion adjustment requirement for individual pieces of combustion equipment at major sources of NO_X in Section XVI.D. The requirements in Section XVI.D.^[51] apply to boilers, duct burners, process heaters, stationary combustion turbines and stationary reciprocating internal combustion engines that have uncontrolled actual NO_X emissions equal to or greater than 5 tpy that existed at major sources of NO_X as of June 3, 2016. Sections XVI.D.2.a-d include inspection and adjustment requirements for boilers, process heaters, duct burners, stationary combustion turbines and stationary internal combustion engines. Section XVI.D.2.e requires owners and operators to operate and maintain equipment subject to Section XVI.D. consistent with manufacturer's specifications or good engineering and maintenance practices. Section XVI.D.2.f outlines combustion adjustment frequency requirements. Section XVI.D.4 sets forth alternative options to the requirements in Sections XVI.D.2.a-e and XVI.D.3.a, including conducting combustion process adjustments according to manufacturer's recommended procedures and schedules, and conducting tune-ups or adjustments according to schedules and procedures of applicable NSPS or NESHAPs.^[52]

We propose to find that the provisions in Section XVI.D are consistent with CAA requirements, and that they strengthen the SIP. Therefore, and for the reasons explained above, we propose to approve the changes in Section XVI.

c. Section XIX

Section XIX establishes RACT requirements for emission points at certain major sources of VOC and NO_X in the DMNFR Area. We are proposing approval of Sections XIX.D, XIX.F., and XIX.G. from the May 31, 2017 submittal. All other parts of Section XIX have been superseded by subsequent submittals. Section XIX.D sets forth emission limits and monitoring, recordkeeping, and reporting (MRR) requirements for major sources of stationary internal combustion engines. Sections XIX.F. and XIX.G. establish requirements for certain major sources to meet RACT.^[53]

We propose to find that the provisions in Section XIX strengthen the SIP, are consistent with CAA requirements, and establish RACT requirements for certain major sources by incorporating federal regulations. We therefore propose to approve the changes in Section XIX.

2. May 14, 2018 SIP Submittal

The State's May 14, 2018 SIP submittal contains amendments to Reg. 7 Sections XII and XVIII to meet RACT for oil and gas sources covered by 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 typographical, grammatical and formatting corrections made to Sections I, II, III, V, VI, VII, VIII, IX, X, XI, XIII, XIV, XV and XVI with Colorado's May 14, 2018 submittal. The revisions in this section are clerical in nature and do not affect the substance of the requirements. Therefore, we propose to approve the changes.

We are not acting on any submitted changes to Sections XII or XVII. These revisions will be acted on at a later date.

3. May 10, 2019 SIP Submittal (Combustion Equipment)

The State's May 10, 2019 SIP submittal contains amendments to Reg. 7, Sections XVI and XIX, establishing categorical and source specific RACT requirements for major sources of VOC and/or NO_X in the DMNFR Area. We propose to approve the changes made to Section XVI except for Section XVI.D.4.b.(i) and XVI.D.4.d. which we will act on at a later date. We also propose to approve the changes made to Section XIX with Colorado's May 10, 2019 submittal.

Below, we describe in detail Colorado's proposed revisions and the basis for our proposed approval of such revisions.

a. Section XVI

As previously stated, Section XVI specifies emission control requirements for stationary and portable combustion equipment. One revision to Section XVI updates the title to the Section. This revision is clerical in nature and does not affect the substance of the requirement.

The other revisions to Section XVI that we are considering in this action concern Section XVI.D., which establishes requirements for major sources of NO_X within the DMNFR Area. Section XVI.D.1. (“Applicability”) establishes the geographic scope of the rule and the sources that are subject to Section XVI.D. requirements. Owners and operators of stationary combustion equipment, as defined in Section XVI.D.3.n., located at a major source of NO_X as of June 3, 2016 in the DMNFR Area, must comply with the requirements of XVI.D. unless exempted under XVI.D.2. We propose to find that this is consistent with CAA requirements.

Section XVI.D.2. outlines exemptions from control requirements in Section XVI.D. Section XVI.D.2.a. contains a 20% capacity factor exemption for boilers and a 10% capacity factor exemption for stationary combustion turbines and compression ignition reciprocating internal combustion engines. The capacity factor exemptions consolidate a number of limited-use exemptions that were analyzed and considered by the Division to limit the complexity of the categorical rules and to adequately accommodate technical and cost concerns for limited-use equipment. Once stationary combustion equipment no longer qualifies for any exemption, the owner or operator must comply with the applicable requirements of Section XVI.D.

Stationary combustion equipment that meets one of the exemptions contained in Section XVI.D.2. is not required to comply with the emission limitations, the compliance demonstration requirements and the related recordkeeping and reporting requirements in Sections XVI.D.4., XVI.D.5., XVI.D.7. and XVI.D.8., except for XVI.D.7.g, which requires a source that qualifies for an exemption under Section XVI.D.2. to maintain records demonstrating that an exemption applies. All stationary combustion equipment is subject to some level of recordkeeping and may also be subject to combustion process adjustment requirements in Section XVI.D.6. The technical support document in the docket for this action has more details on the justification for these exemptions. These exemptions are consistent with exemptions allowed in other state federally enforceable rules,^[54] and meet CAA requirements. Accordingly, we propose to approve these revisions.

Section XVI.D.3. contains definitions specific to Section XVI.D. The definitions are clear, straightforward, and accurate.

Section XVI.D.4. establishes NO_X emission rate limits by source category applicable to emission units operating above the applicability threshold. The source categories, emission limitations, and Reg. 7 rule citation are presented in Table 3. The emission limits contained in the rule are a 30-day rolling average requirement applicable on a year-round basis. A unit subject to an emission limitation must demonstrate compliance by October 1, 2021. The following emission limits established in Section XVI.D.4. are consistent with CAA requirements applicable to the various categories for which ACT documents have been issued and with more recent state and federal NO_X control programs.

Table 3—Affected Sources and NO_X Emission Requirements for Boilers, Engines, Turbines, and Lightweight Aggregate Kilns in the DMNFR Area

Source category	NOX emission limitation (30 day rolling average)	Additional information	Citation
Boilers 55	0.2 lbs/MMBtu	Gaseous and liquid fuel-fired with design heat input ≥100 MMBtu/hr	XVI.D.4.a.
Reciprocating Internal Combustion Engines 56	9.0 g/bhp-hr	Maximum design power output equal to or greater than 500 horsepower	XVI.D.4.e.
Turbines 57	Applicable NOX limits in 40 CFR part 60, subpart KKKK	Maximum design heat input capacity equal to or greater than 10 MMBtu/hr. For turbines that commenced construction, modification, or reconstruction after Feb. 18, 2005	XVI.D.b.(ii).
Lightweight aggregate kilns 58	56.6 lbs NOX per hour		XVI.D.4.c.

By October 1, 2021, owners or operators must determine compliance with emission limitations in Section XVI.D.4. in accordance with one of the methods in Section XVI.D.5. Section XVI.D.5. requires most sources subject to emission limitations to demonstrate compliance using continuous emissions monitoring. For electric generating unit sources, this monitoring is based on 40 CFR part 75 methods, and for industrial sources monitoring is based on 40 CFR part 60 methods. For a few source categories with low variability in operations or emission rates, compliance is demonstrated by periodic stack testing. The emission monitoring requirements are consistent with existing State and EPA programs.

Colorado's May 10, 2019 submittal renumbers the combustion process adjustment requirements in XVI.D.6. (previously Sections XVI.D.1. and 2); clarifies the applicability of the requirements in XVI.D.6.a.; moves definitions for boilers, duct burners, process heaters, stationary combustion turbines and stational internal combustion engines to Section XVI.D.3.; and revises section references in Section XVI.D.6.b.(vi)(B). These revisions do not affect the substance of the Section XVI.D. requirements we propose to approve from the May 31, 2017 submittal. We therefore propose to approve these changes.

Sections XVI.D.7. and 8 require all affected unit owners and operators to maintain records for five years and submit reports to the Division. These records and reports will be used to determine compliance, instances of noncompliance, and to determine if exempt units continue to remain exempt by staying below specific thresholds. These provisions are acceptable.

b. Section XIX

Section XIX establishes RACT requirements for emission points at major sources of VOC and NO_X in the DMNFR Area. We are proposing approval of the renumbering in Section XIX.A from the May 10, 2019 submittal.^[59]

4. May 10, 2019 SIP Submittal (Brewing Activities and Wood Furniture Surface Coating Operations)

The State's May 10, 2019 SIP submittal contains amendments to Reg. 7, Sections I, II, VI, VII, IX, X, XII, XIII, XVI, XVII, XVIII and XX. The revisions include RACT requirements in Section XX for brewing related activities at major VOC sources and RACT requirements in Section IX for wood furniture surface coating operations. The submittal also includes incorporation by reference dates to rules and reference methods in Sections II, VI, VIII, IX, X, XII, XIII, XVI and XVII. Lastly, the submittal contains SIP cleanup revisions in Section I, adds a surface coating work practice in Section IX, and revises an exemption in the industrial cleaning solvent requirements in Section X. Typographical, grammatical and formatting corrections were also made. We propose to approve these changes with Colorado's May 10, 2019 submittal, except for the revisions in Sections XII. and XVIII, which will be acted on at a later date.

a. Sections II, VI, VIII, IX, X, XIII, XV, XVI, XVII, XIX

The changes made in these sections include revisions to specific rule or reference methods incorporated by reference to add applicable citation dates. These changes strengthen the SIP. Other changes throughout these sections are clerical in nature and do not affect the substance of the requirements.

b. Section I

Section I sets forth the applicability of Reg. 7. Sections I.B.2.f. and I.B.2.g. were adopted by the Commission in 1990 and include one-time reporting requirements concerning source emissions and RACT for sources existing as of 1989. The provisions were not an ongoing reporting requirement potentially necessary for monitoring compliance with applicable emissions limits. Since these one-time requirements have passed and Colorado's major stationary sources are now subject to RACT requirements in Reg. 7, as adopted by the Commission through 2018, the Commission removed provisions in I.B.2.f and I.B.2.g. Removal of these provisions does not remove or modify any control measures, and therefore does not affect emissions nor interfere with attainment or reasonable further progress. Where information in the Sections I.B.2.f. and I.B.2.g. reports informed RACT requirements under Section II.C., sources remain subject to applicable RACT requirements and any emission reporting requirements as addressed by the emission statement rule last approved by the EPA in 2015.^[60] The removal of the one-time reporting requirements in I.B.2.f. and I.B.2.g. is reasonable and does not relax the SIP or otherwise interfere with CAA requirements.

Section I.E. deletes language regarding IBR materials available for public inspection. The deletion is reasonable because the same language is contained in the paragraph under “Outline of Regulation” and has updated instructions on how to obtain materials electronically.

c. Section IX

Section IX regulates VOC emissions and establishes RACT requirements for surface coatings operations. Section IX.A.9. sets forth required and prohibited acts for owners and operators of sources of VOCs subject to Section IX. Based on an EPA recommendation, the Commission adopted good air pollution control practices and coating application methods in IX.A.9.a.(ii). We propose to find the provision consistent with CTG recommendations and that it strengthens the SIP.

Section IX.O. establishes new rules for limiting VOC emissions from wood furniture coating operations. These emission reductions are accomplished through limiting VOC content of coatings/materials used, establishing requirements for application equipment, and work practices and recordkeeping requirements.

Section IX.O.2. provides that the rules in section IX.O. apply to wood furniture manufacturing operations, including related cleaning activities, that have the potential to emit 25 tons or more per year of VOCs and that are located in the DMNFR Area. Section IX.O.3. sets forth control requirements for owners and operators of wood manufacturing operations. Requirements include VOC content limits for topcoats, sealers, and strippable booth coatings. Section IX.O.4. adds work practice requirements to minimize material usage and overspray, manage cleanup of wastes, inspect for leaks and provide for the collection of cleaning and washoff solvents and the use of conventional air spray guns. Section IX.O.5. contains reporting requirements to demonstrate compliance with the control requirements in Section IX.O.^[61] A detailed evaluation of Section IX.O. is in the TSD for this action. We propose to find that the provisions in Section IX.O. are consistent with CAA requirements and CTGs, and that they strengthen the SIP. For the reasons previously explained, we propose to approve the changes in Section IX.

d. Section X

As previously discussed, Section X. regulates VOC emissions from the use of cleaning solvents. Section X.E.4. establishes exemptions from the requirements in Section X.E. for industrial cleaning solvent operations. The Commission removed the general exemption in X.E.4.a.(i) and (ii) originally submitted on May 31, 2017 and revised the exemption in X.E.4.a. to apply only to industrial cleaning solvent operations that are subject to another federally enforceable section of Reg. 7 that establishes RACT. The provisions in X.E.4.a. are reasonable and consistent with CAA requirements. We therefore propose to approve the changes in this section.

e. Section XX

Section XX regulates VOC emissions from major source brewery and brewery-related operations. Section XX.A. establishes new rules for limiting emissions from breweries and brewery-related operations at major sources of VOCs as of June 3, 2016. These reductions are accomplished through process line emission limits, packaging operations work practices, wastewater management and treatment and recordkeeping requirements.

Section XX applies to owners or operators of breweries that existed at major sources of VOC in the DMNFR Area as of July 3, 2016. A brewery, as defined in Section XX.A.3.a., includes brewhouse, fermentation, aging and packaging operations. Brewery-related operations include operations that support the production of malt beverages such as wastewater management, container manufacturing and ethanol distillation. Section XX.A.4. sets forth emissions limitations of 6 percent process loss across all packaging operations in a calendar month and 4 percent process loss on a 12-month rolling average during packaging operations. Section XX.A.5. establishes packaging operation work practices including performance metrics to reduce product loss, operator training and packaging equipment to reduce container breakage and product loss. Section XX.A.6. includes requirements for wastewater management and treatment for land application of wastewater. Section XX.A.7. requires owners or operators to keep records of production, pollution prevention activities and wastewater to demonstrate compliance with the operational requirements. A detailed evaluation of Section XX.A. is in the TSD for this action. We propose to find that the provisions in Section XX.A. are consistent with CAA and RACT requirements, and that they strengthen the SIP.

For the reasons previously explained, we propose to approve the changes in Section XX.A.

VII. Proposed Action

For the reasons expressed above, the EPA proposes to approve revisions to Sections I, II, III, V, VI, VII, VIII, IX, X, XI, XIII, XIV, XV, XVI, XVII, XIX and XX of Reg. 7 from the State's May 31, 2017, May 14, 2018 and May 10, 2019 submittals as shown in Table 4, except for those revisions we are not acting on as represented in Table 5. We are proposing to approve Colorado's determination that the above rules constitute RACT for the specific categories addressed in Tables 1 and 2, except for aerospace, for which we are proposing conditional approval.

Finally, the EPA proposes to correct regulatory text and IBR published in the Federal Register on July 3, 2018.^[62]

A comprehensive summary of the revisions in Colorado's Reg. 7 organized by EPA's proposed rule action, reason for proposed “no action” and submittal date are provided in Tables 4 and 5.

Revised Sections in May 31, 2017, May 14, 2018 and May 10, 2019 Submittals Proposed for Approval

May 31, 2017 submittal:

X., X.A.1, X.A.2.b.-j., X.B.1.d.(ii), X.D.1.a.(i), X.E., X.E.1., X.E.1.a.-c., X.E.2., X.E.2.a.-c., X.E.3., X.E.3.a., X.E.3.a.(i)-(iv), X.E.3.b., X.E.3.b.(i)-(iii), X.E.3.b.(iii)(A)-(B), X.E.4., X.E.4.b., X.E.4.b.(i)-(xi), X.E.4.c., X.E.4.c.(i)-(ii), XVI.D., XVI.D.2., XVI.D.2.a.-f.(ii), XVI.D.4., XVI.D.4.a.-b., XIX., XIX.D., XIX.D.1-12., XIX.F. and G.

May 14, 2018 submittal:

I.A.1.c., I.B.1.c., I.B.2.c., I.B.2.e., I.B.2.g., I.B.2.h., II.A.9., II.A.10., II.D.2., III.C., V.B., VI.B.1.a., VI.B.1.b., VI.B.2.a.(i)(C), VI.B.2.a.(i)(E), VI.B.2.a.(iii)(B), VI.B.2.a.(iii)(C), VI.B.2.c.(i)(B)(1), VI.B.2.c.(i)(B)(2), VI.B.2.c.(ii)(B), VI.B.2.c.(ii)(B)(1), VI.B.2.c.(ii)(C)(2), VI.B.2.c.(iii)(A), VI.B.2.c.(iii)(B)(1), VI.B.3.a., VI.B.3.b., VI.B.3.b.(i), VI.B.3.h., VI.C.1., VI.C.2.a., VI.C.2.b., VI.C.2.c., VI.C.3.a.-c., VI.C.3.c.(iii), VI.C.3.d.-f., VI.D.1.a.-b., VI.D.2.a., VI.D.2.a.(i)-(ii), VI.D.2.a.(ii)(A)-(C), VI.D.2.b.(i), VI.D.2.b.(ii)(B), VI.D.3.a., VI.D.3.b., VI.D.4.a.-VI.D.4.c., VI.D.4.c.(ii), VI.D.4.d.(i), VI.D.4.d.(iv), VI.D.4.e., VII.A.2., VII.B.-C., VIII.A.2.a.(i)-(iii), VIII.A.2.a.(iii)(A), VIII.B.6., VIII.C.1., VIII.C.1.b., VIII.C.2.a.(i)-(v), VIII.C.2.a.(vi)(A)-(B), VIII.C.2.c.(iii), VIII.C.4.a.(i)(A), VIII.C.4.a.(i)(A)(6), VIII.C.4.a.(i)(B), VIII.C.4.a.(i)(E), VIII.C.4.a.(ii)-(iii), VIII.C.4.b.(i)(J), VIII.C.4.c.(ii), IX.A.3.c.-e., IX.A.5., IX.A.5.a.-d., IX.A.5.e., IX.A.6.a.-b., IX.A.8.b., IX.A.9.a.(1), IX.A.10.b., IX.A.11., IX.A.12.a., IX.A.12.a.(iv), IX.A.12.a.(vi), IX.A.12.a.(ix), IX.A.12.a.(x), IX.B.2.-5., IX.C.2., IX.D.2., IX.E.2., IX.F.2., IX.G.2., IX.H.1.b., IX.H.2., IX.I.2., IX.J.1.a., IX.J.2., IX.K.1., IX.K.2., IX.L.1.a., IX.L.1.b.(i)-(ii), IX.L.1.c., IX.L.2.a.-c., IX.L.2.c.(iii)-(vi), IX.M.2., IX.M.3.a., IX.N.3.a.(i)(A), IX.N.4.a.(ii), IX.N.5.-6., X.A.5., X.B.1.d.(ii), X.C.1.c.(i), X.C.2.d., X.E.3.b.(i), X.E.4.a.(i), XI.A.1., XI.B.3., XI.C., XIII.A.1.a, XIII.A.3.a.(iii), XIII.A.3.a.(v)-(vi), XIII.A.3.c.-d., XIII.A.4., XIII.B.5.a.-b., XIII.B.5.c., XIV.C.1., XV.B.1.d., XV.B.2.a., XVI.C., XVI.C.1., XVI.C.3.-4., XVII.E.3.a.(i), XVII.E.3.a.(i)(A)-(C).

May 10, 2019 submittal—RACT for combustion sources:

XVI., XVI.D., XVI.D.1.-XVI.D.4.a.(ii), XVI.4.b.(ii)-(iii), XVI.D.4.c., XVI.D.4.e.-XVI.D.5.a.(iv), XVI.D.6. (renumbering), XVI.D.6.a., XVI.D.6.b.-XVI.D.6.b.(vi)(B) (renumbering), XVI.D.6.c., XVI.D.6.c.(i)-(ii) (renumbering), XVI.D.7.-XVI.D.8.b.(i), XIX.A. (renumbering).

May 10, 2019 submittal—RACT for brewing related activities and wood furniture surface coating operations:

I.B.2.f.-g., I.E., II.A.17., VI.B.2.a.(i)(D), VI.B.3.i., VI.C.2.d.-e., VI.D.3.c., VI.D.4.d.(v), VIII.A.2.a.(iii)(B), VIII.B.7., VIII.C.3., IX.A.1., IX.A.3.a., IX.A.9.a.(i), IX.A.9.a.(ii), IX.A.10.b., IX.A.11., IX.L.2.c.(vi), IX.N.7., IX.O.-IX.O.5.a.(v), X.D.2.a., X.E.3.b.(iii)(A)-(B), X.E.4.a., X.E.4.c.-(ii), XIII.B.5.c.(iii)(A)-(B), XV.B.1.b., XVI.D.6.b.(vi)(A), XVI.D.6.c.(ii), XVI.D.7.f.(iii), XVII.E.3.a.(i)(B), XIX.B.-C. (renumbering), XX.-XX.A.7.c.

Table 5—List of Colorado Revisions to Reg. 7 That EPA Is Proposing To Take No Action on

Revised section	Reason for proposed “No Action”
	Superseded by May 10, 2019 submittal	Revision to be made in future rulemaking	Revision never approved into the SIP
May 31, 2017 submittal:
X.E.4.a	X
X.E.4.a.(i)-(ii)	X
XVI.D.1	X
XVI.D.1.A.-e	X
XVI.D.3	X
XVI.D.3.a.-c	X
XV.I.D.4.c	X
XIX.A.-C	X
XIX.E	X
May 14, 2018 submittal:
II.B		X
Section XII		X
XVI.D.2.a.(iv)	X
XVI.D.3.a.(ii)-(iii)	X
XVI.D.4	X
Section XVIII		X
May 10, 2019 submittal—RACT for combustion sources:
XVI.D.4.b.(i)		X
XVI.D.4.d		X
May 10, 2019 submittal—RACT for brewing related activities and wood furniture surface coating operations:
X.E.4.a.(i)-(ii)			X
XIX.B			X
Section XII		X
Section XVIII		X

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 INFORMATION CONTACT section of this preamble for more information).

IX. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submittal 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 submittals, the EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this action merely proposes to approve state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this action:

• Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because SIP approvals are exempted under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and
• Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the proposed rule does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects in 40 CFR Part 52

• Environmental protection
• Air pollution control
• Carbon monoxide
• Greenhouse gases
• Incorporation by reference
• Intergovernmental relations
• Lead
• Nitrogen dioxide
• Ozone
• Particulate matter
• Reporting and

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

Dated: September 4, 2020.

Gregory Sopkin,

Regional Administrator, EPA Region 8.

Footnotes

1.  See 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, National Ambient Air Quality Standards for Ozone, 73 FR 16436 (March 27, 2008).

3.  40 CFR 50.15(b).

4.  Final rule, Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards, 77 FR 30088 (May 21, 2012).

5.  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.

6.  40 CFR part 50, appendix I.

7.  See 40 CFR 51.903.

8.  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); see 40 CFR 81.306.

9.  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.

10.  83 FR at 31068. Under the Moderate classification, the Denver Area was required to attain the standard by July 20, 2018. It did not do so, and as a result has been reclassified to Serious nonattainment status. 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 (Dec. 26, 2019).

11.  Final rule, Colorado: Approval and Promulgation of State Implementation Plans, 46 FR 16687 (March 13, 1981).

12.  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).

13.  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).

14.  Final rule, Approval and Promulgation of Implementation Plans; State of Colorado; Regional Haze State Implementation Plan, 77 FR 76871 (Dec. 31, 2012).

15.  In this document we are correcting the previous inadvertent omission of IBR material from the regulatory text for this action.

16.  See 83 FR at 31068, 31071.

17.  See 83 FR at 31068.

18.  On June 29, 2018, the EPA provided comments on Colorado's revised draft ozone SIPs for the DMNFR Area, including the TSD and rules in Reg. 7, Section XVI.D.4. These written comments from the EPA included some comments applicable to the rules we are proposing to act on today. The comment letters can be found within the docket for this action at www.regulations.gov.

19.  CAA section 110(a)(2), 42 U.S.C. 7410(a)(2),

20.  CAA section 172(c)(1), 42 U.S.C. 7502(c)(1).

21.  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).

22.  See https://www.epa.gov/​ground-level-ozone-pollution/​control-techniques-guidelines-and-alternative-control-techniques (accessed April. 27, 2020) for a list of EPA-issued CTGs and ACTs (also available within the docket).

23.  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.

24.  See CAA sections 182(b), 42 U.S.C. 7511a(b); and 302(j), 42 U.S.C. 7602(j).

25.  See Memorandum, “Approval Options for Generic RACT Rules Submitted to Meet the non-CTG VOC RACT Requirement and Certain NO_X 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.

26.  The Commission also adopted miscellaneous metal surface coating requirements. We will be making our RACT determination for these sources in a future rulemaking.

27.  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).

28.  See https://www.epa.gov/​ground-level-ozone-pollution/​ractinformation.

29.  See EPA's TSD for a full analysis of Colorado's rules as they relate to EPA guidelines and available technical information. We will be acting on the RACT demonstrations for the Oil and Gas 2016 CTG source category, the Miscellaneous Metal Products Coatings category, and for sources of NO_X in the categories for process heaters, glass melting furnaces, and pre 2005 turbines in a future action.

30.  See 76 FR at 47443 and 83 FR at 31069-31070.

31.  See p. 1126 of the May 31, 2017 submittal for Colorado's RACT demonstration for Metal furniture coatings.

32.  See p. 1115 and p. 1135 of the May 31, 2017 submittal, and p. 24 of the State of Colorado Categorical Reasonable Available Control Technology Review for Brewing and Wood Furniture Surface Coating TSD, October 30, 2018, document set 21 (contained within the May 10, 2019 submittal).

33.  See p. 1116 of the May 31, 2017 submittal.

34.  See Colorado's August 4, 2020 letter committing to submit to EPA a negative declaration certifying that there are no sources in the DMNFR Area above the aerospace CTG applicability threshold (contained within the docket). The EPA proposes to conditionally approve Colorado's determination that there are no sources in the DMNFR Area subject to the aerospace CTG and therefore RACT is satisfied for this category. If we finalize our proposed conditional approval, Colorado must submit the negative declaration, after state notice and public hearing, to EPA within one year of our finalization. If Colorado does not submit the negative declaration within one year, or if we find Colorado's revisions to be incomplete, or we disapprove Colorado's revisions, this conditional approval will convert to a disapproval. If any of these occur and our conditional approval converts to a disapproval, that will constitute a disapproval of a required plan element under part D of title I of the Act, which starts an 18-month clock for sanctions, see CAA section 179(a)(2), and the two-year clock for a federal implementation plan, see CAA section 110(c)(1)(B).

35.  See 83 FR at 31068 and section V of this proposed rule.

36.  The EPA previously approved Colorado's rule revisions and RACT analyses for VOCs into Colorado's SIP under the 1-hour ozone standard. See Final rule, Approval and Promulgation of Air Quality Implementation Plans; Colorado; Regulation 7, 60 FR 28055 (May 30, 1995).

37.  See the EPA's TSD for a full analysis of Colorado's rules as they relate to EPA guidelines and available technical information.

38.  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).

39.  See pp. 21-26 of the Categorical Reasonably Available Control Technology Review for Boilers, Turbines, Engines, Glass Melt Furnaces and Aggregate Kilns and Major NO_X Sources in the Denver Metro/North Front Range Ozone Nonattainment Area, July 2018. Contained within the May 10, 2019 submittal for combustion equipment (document set 25).

40.  See id. pp. 9-15.

41.  See id. pp. 16-21.

42.  See id. pp. 9-15.

43.  See May 31, 2017 submittal at 1145; Technical Support Document for Reasonably Available Control Technology for Major Sources, at 3005 (Nov. 17, 2016) (contained in the May 10, 2017 submittal).

44.  See id. at 3015-3016.

45.  See State of Colorado Categorical Reasonable Available Control Technology Review for Brewing and Wood Furniture Surface Coating TSD, document set 21, at 5-24 (Oct. 30, 2018) (contained in the May 10, 2019 submittal).

46.  See 83 FR at 31068 and section V of this proposed rule.

47.  83 FR at 31068.

48.  All other sections of Reg. 7 addressed in the May 31, 2017 submission have been superseded by the State's May 14, 2018 and May 10, 2019 submissions. The EPA is not acting on the superseded earlier submissions.

49.  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.

50.  Renumbered to XVI.D.6.b. in May 10, 2019 submittal.

51.  Sections XVI.D.1, XVI.D.1(a)-(e), and XVI.D.3. are superseded by the May 10, 2019 submittal.

52.  See also p. 3082 of the May 31, 2017 submittal (contained within the docket).

53.  See the TSD associated with this action for a detailed RACT analysis associated with these revisions.

54.  See, e.g., Wisconsin Control of Nitrogen Compound Emissions rule, Wis. Admin. Code NR § 428.08 (2020).

55.  See Table 4 in Colorado's “Categorical RACT Review for Boilers, Turbines, Engines, Glass Melt Furnaces and Aggregate Kilns at Major NO_X Sources in the DMNFR NAA” TSD (July 2018) for a list of boilers potentially subject to XVI.D.4.a.

56.  See Table 11 in Colorado's TSD (July 2018) for a list of compression ignition engines potentially subject to XVI.D.e.

57.  See Table 9 in Colorado's TSD (July 2018) for a list of turbines potentially subject to XVI.D.e.

58.  There is one lightweight aggregate kiln at a major source of NO_X in the DMNFR NAA. RACT for this kiln is analyzed on p. 28-30 in Colorado's TSD (July 2018).

59.  Sections XIX.A.-C. were originally submitted to EPA on May 31, 2017 and listed by name major sources of VOC and/or NO_X, required owners or operators of major sources to submit RACT analyses to the Division by December 31, 2017, and set a compliance date for turbines to meet emission limits and MRR requirements. The EPA did not act on Section XIX with our April 6, 2018 (83 FR 14807) rulemaking. Colorado's May 10, 2019 submission deletes Sections XIX.A-C, but since the provisions were never approved into the SIP, we are taking no action on the deleted portions of the submission.

60.  See 80 FR 50205 (Aug. 19, 2015).

61.  Operators and owners of wood furniture manufacturing operations subject to Section IX.O. are also subject to requirements in Section IX.A.1.-IX.A.9.

62.  83 FR 31068.