The eRulemaking Program

11/06/2024 | Press release | Distributed by Public on 11/06/2024 07:23

Air Quality State Implementation Plans; Approvals and Promulgations: Pennsylvania; Adoption of Federal Implementation Plan Reasonably Available Control Technology Requirements[...]

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R03-OAR-2024-0302; FRL-12064-02-R3]

Air Plan Approval; Pennsylvania; Adoption of Federal Implementation Plan Reasonably Available Control Technology Requirements for Keystone, Conemaugh, Homer City, and Montour Generating Facilities for the 1997 and 2008 Ozone National Ambient Air Quality Standards

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

The Environmental Protection Agency (EPA) is approving a portion of the state implementation plan (SIP) revisions submitted by the Commonwealth of Pennsylvania. The revisions being approved adopt nitrogen oxides (NO X ) emission limits and requirements for the coal-fired electric generating units (EGUs) equipped with selective catalytic reduction (SCR) at the Keystone, Conemaugh, Homer City, and Montour facilities. The NO X limits address reasonably available control technology (RACT) requirements for these EGUs for the 1997 and 2008 ozone national ambient air quality standards (NAAQS) and address the deficiencies identified in EPA's August 16, 2022, disapproval of an earlier SIP submission. This action is being taken under the Clean Air Act (CAA).

DATES:

This final rule is effective on December 6, 2024.

ADDRESSES:

EPA has established a docket for this action under Docket ID Number EPA-R03-OAR-2024-0302. All documents in the docket are listed on the www.regulations.gov website. Although listed in the index, some information is not publicly available, e.g., confidential business information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available through www.regulations.gov, or please contact the person identified in the FOR FURTHER INFORMATION CONTACT section for additional availability information.

FOR FURTHER INFORMATION CONTACT:

Sean Silverman, Planning & Implementation Branch (3AD30), Air & Radiation Division, U.S. Environmental Protection Agency, Region III, 1600 John F Kennedy Boulevard, Philadelphia, Pennsylvania 19103. The telephone number is (215) 814-5511. Mr. Silverman can also be reached via electronic mail at [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

On August 16, 2022, (87 FR 50257) EPA took final action to disapprove portions of a Pennsylvania SIP revision submitted May 16, 2016 that, among other things, established NO X emission limitations for the coal-fired EGUs equipped with SCR at the Keystone, Conemaugh, Homer City, and Montour facilities, to satisfy certain RACT obligations for the 1997 and 2008 ozone NAAQS. (1) EPA's August 16, 2022, final disapproval started a sanctions clock under CAA section 179 and 40 CFR 52.31. The two-to-one new source emissions offset sanction took effect on March 15, 2024 (18 months following the September 15, 2022, effective date of the August 16, 2022, disapproval, 87 FR 50257). Highway funding sanctions would have taken effect September 15, 2024, unless the state submitted, and EPA approved, SIP revisions correcting the deficiencies identified in the August 16, 2022, disapproval action.

On August 31, 2022, EPA issued a Federal implementation plan (FIP) adopting NO X RACT limits for these four sources addressing these same RACT obligations. 87 FR 53381. Three of the sources subject to the FIP filed a challenge to the FIP in the U.S. Third Circuit Court of Appeals. Keystone-Conemaugh Projects LLC v. EPA, et al., No. 22-3026. Following briefing and oral argument, on May 2, 2024, the Third Circuit issued a decision upholding the RACT limits and other requirements in EPA's August 31, 2022, FIP. The court decided and resolved all issues raised by the Petitioners in EPA's favor. Id.

On April 10, 2024, Pennsylvania Department of Environmental Protection (PADEP) submitted two SIP revisions to EPA which adopted into the SIP the NO X limits and other requirements found in EPA's final August 31, 2022, FIP for Keystone, Conemaugh, Homer City, and Montour (Montour was submitted separately). On July 10, 2024, EPA published a notice of proposed rulemaking (NPRM) proposing to approve Pennsylvania's April 10, 2024, SIP revisions (89 FR 56680). EPA's NPRM also proposed to find that the incorporation of title V permits containing the FIP requirements into Pennsylvania's SIP addressed the deficiencies identified in EPA's August 16, 2022 (87 FR 50257), partial disapproval. The reasons for the proposed approval and the determination were stated in the proposal for this action and will not be restated here. Based on this finding and the proposed approval, EPA simultaneously issued an Interim Final Determination (IFD) staying the application of the offset sanction and deferring the application of the highway sanction triggered by EPA's August 16, 2022 (87 FR 50257) disapproval. 89 FR 56666 (July 10, 2024). EPA's proposed action noted that it was not taking action at this time on certain RACT limits for auxiliary boilers which were included in the SIP revisions, and therefore this final action does not address those RACT limits for the identified auxiliary boilers.

The public comment period for the proposed approval and determination ended on August 9, 2024. EPA received three comments, which can be found in the docket. One of the comments is not relevant to this action and will not be addressed. The other two were supportive, but one generally supportive comment also contained comments which could be considered adverse. Those potentially adverse comments are addressed below.

II. Summary of SIP Revision and EPA Analysis

Pennsylvania's SIP submissions, dated April 9, 2024, and received by EPA on April 10, 2024, included four redacted title V permits incorporating the FIP requirements for the EGUs equipped with SCR at Keystone, Conemaugh, Homer City, and Montour. EPA has reviewed these permits and determined that the permits incorporate the same emission limits, monitoring, testing, recordkeeping, reporting, work practices and other requirements for these EGUs found in EPA's FIP. The permits are listed in Table 1 in this document. These submissions and permits are part of the docket for this rule making and are available online at www.regulations.gov.

Table 1-List of Title V permits incorporating the Requirements of the August 31, 2022, Federal Implementation Plan
Source name Title V permit No. County Permit effective date
Conemaugh 32-0059 Indiana March 14, 2024.
Homer City 32-00055 Indiana March 14, 2024.
Keystone 03-00027 Armstrong March 14, 2024.
Montour 47-00001 Montour March 14, 2024.

The title V permits in the April 10, 2024, SIP submissions for Keystone and Conemaugh also contain case-by-case RACT limits for certain gas or oil-fired auxiliary boilers at these facilities. However, EPA is not taking action at this time on the case-by-case RACT limits in these permits for two auxiliary boilers at Keystone (Source IDs 037 and 038) and two at Conemaugh (Source IDs 039 and 041). These auxiliary boilers were not subject to the presumptive RACT limit in 25 Pa. Code 129.97(g)(1)(viii) for which EPA issued a final disapproval in August 2022.

As explained in the proposed action, EPA's assessment regarding the approvability of the RACT limits and other requirements for these EGUs found in Pennsylvania's SIP submission is substantially the same as the justification and analysis in the record EPA created for its FIP. EPA provided an in-depth discussion of the methodology and reasoning for setting the FIP limits for each of these EGUs in EPA's proposed FIP (87 FR 31798, May 25, 2022), the associated technical support document supporting the proposed FIP, and in responses to comments received on the proposed FIP and published with the final FIP action (87 FR 53381, August 31, 2022). EPA has put the technical support document for EPA's FIP into the docket for this action. The Federal Register documents for the proposed and final FIP are available at www.regulations.gov under docket number EPA-R03-OAR-2022-0347 and in the Federal Register at the citations provided in the prior sentence. EPA is not aware of any change in the facts since the FIP was finalized that would alter any of the limits or requirements or EPA's analysis supporting the FIP. Other specific requirements of Pennsylvania's April 10, 2024, submittal and the rationale for EPA's proposed action are explained in the NPRM and will not be restated here.

III. EPA's Response to Comments Received

EPA received three comments on the July 10, 2024, documents. One comment is not relevant to this action and will not be addressed. A summary of the other two comments and EPA's responses follow. Copies of all the comments are in the docket for this rule action.

Comment 1: The commenter first acknowledges some key historical developments concerning the NO X RACT requirements for the Keystone and Conemaugh EGUs, including PADEP's prior SIP submission of May 26, 2022, EPA's proposed disapproval of that SIP submission, PADEP's withdrawal of that SIP submission following EPA's proposed disapproval, and the May 2, 2024, decision by the Third Circuit Court of Appeals upholding the RACT limits and other requirements in EPA's August 31, 2022, FIP. The commenter then states that they "[support] the EPA's effort to finalize the SIP as prepared by the PADEP."

The commenter then notes that "the challenges of operating under these limits that KEY-CON noted during the rulemaking process for the FIP remain." The commenter asserts that in order to account for start-up events where higher NO X emissions above the limit are unavoidable, the sources must operate at a target NO X emission rate that is lower than each sources' limit. The commenter acknowledges that "operating in this manner provides a manageable balance for maintaining an adequate (but small) margin of compliance and limiting excessive aqueous ammonia injection rates that are required to achieve lower NO X emission rates." The comment notes that extended periods of excessive ammonia injection can lead to fouling of the air preheaters, and that this problem is exacerbated in colder weather. As a result, the commenter states that the frequency of conducting heater washes, as well as SCR reactor maintenance, has increased, and that the limits in the proposed rulemaking "are at the very bounds of our NO X emissions control capability."

Response 1: EPA thanks the commenter for their largely supportive comment, and agrees that PADEP's April 10, 2024, SIP revision incorporating the NO X limits from EPA's FIP should be finally approved and incorporated in the Pennsylvania SIP to meet certain RACT requirements for these sources for the 1997 and 2008 Ozone NAAQS. The commenter's concerns regarding fouling of the air preheaters with ammonium bisulfate (ABS) under certain conditions and the need for increased maintenance to address this fouling are similar to those contained in the commenter's July 11, 2022, comments on EPA's proposed FIP. EPA addressed those comments in the final rule adopting the FIP limits. See 87 FR 53381, at 53390 and 53391, August 31, 2022. However, the commenter now goes on to state that the current limits and other requirements provide "a manageable balance for maintaining an adequate (but small) margin of compliance." EPA agrees that this balance is appropriate in light of the longstanding definition of RACT 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."  (2) Table 2, in this preamble are citations to the specific places in the final rule approving the FIP limit where EPA responded to similar concerns expressed by the commenter.

Table 2-Citations to Relevant Portions of the FIP
Topic Citation in FIP FRN
Concerns about Fouling 87 FR 53381 at 53390 second column.
No specific setpoint is required, the 30-day average provides flexibility in meeting the limit 87 FR 53381 at 53390 third column.
The increase in ammonium bisuflate salt formation in colder temps 87 FR 53381 at 53395 second column.
EPA used weighted averages and the third best to provide flexibility for start-up events 87 FR 53381 at 53396 second column and third column.

In addition to the above concerns, the commenter expresses concern that in the future, more restrictive limits might be placed on these units in order to meet RACT requirements for the 2015 ozone NAAQS. Although Pennsylvania has adopted regulations setting RACT limits for certain major sources of VOCs and NO X (See 25 Pa. Code 129.111-129.115) for the 2015 ozone NAAQS, those regulations do not set NO X limits for coal-fired EGUs equipped with SCR. When PADEP develops case-by-case RACT limits for the commenter's sources and submits them to EPA for approval as a SIP revision, there will be another opportunity for the commenter to share information on whether any new but lower NO X limits are technologically and economically feasible.

Comment 2: The commenter states:

I am writing to provide comments on the interim final determination to stay and defer sanctions related to the Reasonably Available Control Technology (RACT) requirements for the Keystone, Conemaugh, Homer City, and Montour generating facilities in Pennsylvania under the 1997 and 2008 Ozone National Ambient Air Quality Standards (NAAQS). While the intent of deferring sanctions might be to allow time for compliance, there are critical aspects that need to be carefully considered. It is essential that the control measures adopted for these facilities are strict and in line with the most current technologies and practices. The stay should not compromise the effectiveness of RACT in reducing emissions. Adequate and enforceable measures must be established to achieve the required air quality improvements and standards. There should be procedures and rules such facilities are monitored and held accountable for their actions to ensure that facilities are taking substantive steps toward compliance. There should be regular reports to ensure everything is going smoothly.

Response 2: EPA agrees that it is essential that control measures adopted for these facilities be strict and in line with current technologies and practices, so long as those technologies and practices meet the definition of RACT. EPA's longstanding definition of RACT is "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."  (3) EPA also agrees that the RACT limits must be accompanied by enforceable measures, appropriate monitoring, recordkeeping, and reporting to ensure compliance. EPA believes that the requirements of its FIP, and this SIP revision adopting the same FIP requirements, achieve RACT levels of control and provide the necessary monitoring, recordkeeping, and reporting needed to ensure enforcement of the limits. EPA also notes that the RACT limits and other requirements for these sources have been enforceable since March 29, 2023, which was the initial compliance date for the limits set forth in the FIP issued by EPA on September 30, 2022. 87 FR 53381. Regarding the IFD, EPA notes that the IFD only stayed the application of the offset sanction and deferred the application of the highway funding sanctions. The IFD does not in any way impact the RACT requirements the facilities must meet in the FIP.

IV. Final Action

EPA is approving Pennsylvania's April 10, 2024, SIP revision to the Pennsylvania SIP, with the exception of certain RACT limits for auxiliary boilers, as set forth in EPA's NPRM. In addition, EPA is determining that Pennsylvania's April 10, 2024, SIP revision addressed the deficiencies identified in EPA's August 16, 2022 (87 FR 50257) partial disapproval. Finalization of this approval permanently stops the offset sanctions which took effect on March 15, 2024, and prevents the imposition of highways sanctions which could have taken effect on September 15, 2024.

V. Incorporation by Reference

In this document, EPA is finalizing regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, EPA is finalizing the incorporation by reference of source-specific RACT determinations and alternative NO X emissions limits under the 1997 and 2008 8-hour ozone NAAQS for certain major sources of NO X in Pennsylvania described in section II. of this preamble and as set for the below in the amendments to 40 CFR part 52. EPA has made, and will continue to make, these materials generally available through www.regulations.gov and at the EPA Region III Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information). Therefore, these materials have been approved by EPA for inclusion in the SIP, have been incorporated by reference by EPA into that plan, are fully federally enforceable under sections 110 and 113 of the CAA as of the effective date of the final rule of EPA's approval, and will be incorporated by reference in the next update to the SIP compilation. (4)

VI. Statutory and Executive Order Reviews

A. General Requirements

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this action merely approves 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);

• 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); and
  • 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 Clean Air Act;

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 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. EPA defines environmental justice (EJ) as "the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies." EPA further defines the term fair treatment to mean that "no group of people should bear a disproportionate burden of environmental harms and risks, including those resulting from the negative environmental consequences of industrial, governmental, and commercial operations or programs and policies."

The Pennsylvania Department of Environmental Protection did not evaluate environmental justice considerations as part of its SIP submittal; the CAA and applicable implementing regulations neither prohibit nor require such an evaluation. EPA did not perform an EJ analysis and did not consider EJ in this action. Due to the nature of the action being taken here, this action is expected to have a neutral to positive impact on the air quality of the affected area. Consideration of EJ is not required as part of this action, and there is no information in the record inconsistent with the stated goal of E.O. 12898 of achieving environmental justice for people of color, low-income populations, and Indigenous peoples.

B. Submission to Congress and the Comptroller General

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. Section 804, however, exempts from section 801 the following types of rules: Rules of particular applicability; rules relating to agency management or personnel; and rules of agency organization, procedure, or practice that do not substantially affect the rights or obligations of non-agency parties. 5 U.S.C. 804(3). Because this is a rule of particular applicability, EPA is not required to submit a rule report regarding this action under section 801.

C. Petitions for Judicial Review

Under section 307(b)(1) of the CAA, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by January 6, 2025. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed and shall not postpone the effectiveness of such rule or action. This action addressing the NO X RACT requirements for EGUs equipped with SCR at the Keystone, Conemaugh, Homer City and Montour facilities for the 1997 and 2008 Ozone NAAQS may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Incorporation by reference, Nitrogen dioxide, Ozone, Reporting and recordkeeping requirements.

Adam Ortiz,
Regional Administrator, Region III.

For the reasons stated in the preamble, the EPA amends 40 CFR part 52 as follows:

PART 52-APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

Regulatory Text

1. The authority citation for part 52 continues to read as follows:

Authority:

42 U.S.C. 7401 et seq.

Subpart NN-Pennsylvania

Regulatory Text

2. Amend § 52.2020:

a. In the table in paragraph (d)(1) by

i. Removing the entry for "Pennsylvania Power and Light Co. (PP&L)-Montour" and inserting in its place the entry "Montour LLC/Montour SES"; and

ii. Removing the entry for "Pennsylvania Electric Co. (PENELEC)-Keystone Generating Station" and inserting in its place the entry "Keystone Conemaugh Proj LLC/Keystone Station"; and

b. In the table in paragraph (d)(3) by:

i. Removing the entry for "Conemaugh Plant, Genon NE Management Co" Permit No. "Title V permit 32-00059" and inserting in its place the entry "Keystone Conemaugh Proj LLC/Conemaugh Station"; and

ii. Removing the entry for "Homer City Generation" Permit No. "Plan Approvals 32-00055H and 32-00055I" and inserting in its place the entry "Homer City Gen LP/Center TWP".

The revisions read as follows:

§ 52.2020 Identification of plan.

* * * * *

(d) * * *

(1) * * *

Name of source Permit No. County State effectivedate EPA approval date Additional explanations/§§  52.2063 and 52.2064 citations  1
*         *         *         *         *         *         *
Keystone Conemaugh Proj LLC/Keystone Station 32-00027 Armstrong 3/14/2024 11/6/2024, [INSERT FIRST PAGE OF FR CITATION] NO X RACT emission limits and associated compliance parameters in unredacted portions of the Title V permit provided to EPA on April 10, 2024. Permit name updated in this table. See also 52.2064(m)(3).
*         *         *         *         *         *         *
Montour LLC/Montour SES 47-00001 Montour 3/14/2024 11/6/2024, [INSERT FIRST PAGE OF FR CITATION] NO X RACT emission limits and associated compliance parameters in unredacted portions of the Title V permit provided to EPA on April 10, 2024. Permit name updated in this table. See also 52.2064(m)(4).
*         *         *         *         *         *         *

* * * * *

(3) * * *

Name of source Permit No. County State effectivedate EPA approval date Additional explanation/§ 52.2063 citation
*         *         *         *         *         *         *
Keystone Conemaugh Proj LLC/Conemaugh Station Title V permit 32-00059 Indiana 3/14/2024 11/6/2024, [INSERT FIRST PAGE OF FR CITATION] NO X RACT emission limits and associated compliance parameters in unredacted portions of the Title V permit provided to EPA on April 10, 2024. Permit name updated in this table. See also 52.2064(m)(1).
*         *         *         *         *         *         *
Homer City Gen LP/Center TWP 32-00055 Indiana 3/14/2024 11/6/2024, [INSERT FIRST PAGE OF FR CITATION] NO X RACT emission limits and associated compliance parameters in unredacted portions of the Title V permit provided to EPA on April 10, 2024. Permit name updated in this table. See also 52.2064(m)(2).
*         *         *         *         *         *         *

* * * * *

3. Amend § 52.2064 by adding paragraph (m) to read as follows:

§ 52.2064 EPA-approved Source-Specific Reasonably Available Control Technology (RACT) for Volatile Organic Compounds (VOC) and Oxides of Nitrogen (NO X ).

* * * * *

(m) Approval of source-specific RACT requirements for 1997 and 2008 8-hour ozone national ambient air quality standards for the facilities listed in this paragraph (m) are incorporated as specified. (Rulemaking Docket No. EPA-R03-OAR-2024-0302.)

(1) Keystone Conemaugh Proj LLC/Conemaugh Station-Incorporating by reference Permit No. 32-00059, effective March 14, 2024, as redacted by Pennsylvania, excluding the auxiliary boiler limits for all source group requirements in section E for G11: alternative RACT II for Auxiliary Boilers source IDs 039 and 041. See also § 52.2020(d)(1), for prior RACT approval.

(2) Homer City Gen LP/Center TWP-Incorporating by reference Permit No. 32-00055, effective March 14, 2024, as redacted by Pennsylvania. See also § 52.2020(d)(1), for prior RACT approval.

(3) Keystone Conemaugh Proj LLC/Keystone Station-Incorporating by reference Permit No. 32-00027, effective March 14, 2024, as redacted by Pennsylvania, excluding the auxiliary boiler limits for all source group requirements in section E for G11: alternative RACT II for Auxiliary Boilers source IDs 037 and 038. See also § 52.2020(d)(1), for prior RACT approval.

(4) Montour LLC/Montour SES-Incorporating by reference Permit No. 47-00001, effective March 14, 2024, as redacted by Pennsylvania. See also § 52.2020(d)(1), for prior RACT approval.

[FR Doc. 2024-25604 Filed 11-5-24; 8:45 am]
BILLING CODE 6560-50-P

Footnotes

(1)  A more detailed and complete summary of the history of the RACT limits for these EGUs can be found in the Notice of Proposed Rulemaking for this final action. 89 FR 56680 (July 10, 2024).

(2)  Memo, dated December 9, 1976, from Roger Strelow, Assistant Administrator for Air and Waste Management, to Regional Administrators, "Guidance for Determining Acceptability of SIP Regulations in Non-Attainment Areas," p. 2, available at www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19761209_strelow_ract.pdf and 44 FR 53762 (September 17, 1979) (Strelow Memo).

See also Sierra Club v. EPA, 972 F.3d 290.

(3)  Memo, dated December 9, 1976, from Roger Strelow, Assistant Administrator for Air and Waste Management, to Regional Administrators, "Guidance for Determining Acceptability of SIP Regulations in Non-Attainment Areas," p. 2, available at www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19761209_strelow_ract.pdf and 44 FR53762 (/citation/44-FR-53762), footnote 2 (September 17, 1979) (Strelow Memo).

See also Sierra Club v. EPA, 972 F.3d 290.

(4)  62 FR 27968 (May 22, 1997).