Air Plan Approval; Pennsylvania; Proposed Revision to Philadelphia Gas Works, Richmond Plant Reasonably Available Control Technology Plan Under the 1997 8-Hour Ozone National Ambient Air Quality Standards

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R03-OAR-2025-2831; FRL-13067-01-R3]</DEPDOC> <SUBJECT>Air Plan Approval; Pennsylvania; Proposed Revision to Philadelphia Gas Works, Richmond Plant Reasonably Available Control Technology Plan Under the 1997 8-Hour Ozone National Ambient Air Quality Standards</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA or “the Agency”) is proposing to approve a State implementation plan (SIP) revision submitted by the Commonwealth of Pennsylvania. In this rulemaking, the EPA proposes to approve a revision to the reasonably available control technology (RACT) Plan for the Philadelphia Gas Works, Richmond Plant (PGW Richmond), a major source of nitrogen oxides (NO <E T="52">X</E> ). The proposed revision would remove a condition from the RACT Plan Approval, previously incorporated into Pennsylvania's SIP on October 7, 2016. The proposed revision results in no change of emission allowances under RACT. This action is being taken under the Clean Air Act (CAA). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before March 9, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R03-OAR-2025-2831 at <E T="03">www.regulations.gov,</E> or via email to <E T="03">talley.david@epa.gov.</E> For comments submitted at <E T="03">Regulations.gov,</E> follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">Regulations.gov.</E> For either manner of submission, 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 ( <E T="03">i.e.,</E> on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the <E T="02">For Further Information Contact</E> section. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit <E T="03">www.epa.gov/dockets/commenting-epa-dockets.</E> <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Katharine Payne, Permits Branch (3AP10), Air & Radiation Division, U.S. Environmental Protection Agency, Region III, 1600 John F. Kennedy Boulevard, Philadelphia, Pennsylvania 19103. The telephone number is (215) 814-2183. Ms. Katharine Payne can also be reached via electronic mail at <E T="03">payne.katharine@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> On September 7, 2023, the Pennsylvania Department of Environmental Protection (PADEP) submitted on behalf of the City of Philadelphia, Department of Public Health, Air Management Services (AMS) a proposed revision to the Pennsylvania SIP to satisfy the RACT requirements for the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS) for Philadelphia. <HD SOURCE="HD1">I. Background</HD> <HD SOURCE="HD2">A. General</HD> Section 172(c)(1) of the CAA provides that SIPs for nonattainment areas must include reasonably available control measures (RACM) for attainment of the NAAQS, including emissions reductions from existing sources through adoption of RACT. Sections 182(b)(2) and (f)(1) of the CAA require States with moderate, or worse, ozone nonattainment areas to implement RACT controls on each category of stationary sources covered by a control technique guideline (CTG) document issued by the EPA and on all major stationary sources of volatile organic compounds (VOC) and NO <E T="52">X</E> emissions located in the nonattainment area. <SU>1</SU> <FTREF/> <FTNT> <SU>1</SU>  A major source in an ozone nonattainment area is defined as any stationary source that emits or has the potential to emit NO <E T="52">X</E> and VOC emissions above a certain applicability threshold that is based on the classification of the ozone nonattainment area. See “major stationary source” in 40 CFR 51.165. </FTNT> On July 18, 1997 (62 FR 38856), the EPA revised the NAAQS for ground-level ozone, setting the standard at 0.08 parts per million (ppm) averaged over an 8-hour time frame. On April 15, 2004, the EPA issued final designations for the 1997 8-hour ozone NAAQS, which included Philadelphia County as part of the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE moderate ozone nonattainment area. See 69 FR 23858, at 23931 (April 30, 2004). The nonattainment designation for Philadelphia under the 1997 8-hour ozone NAAQS, and its location in the ozone transport region (OTR), triggered Pennsylvania's obligation to submit a SIP revision addressing how it meets the CAA RACT requirements in Philadelphia under this standard. On March 27, 2008 (73 FR 16436), the EPA significantly strengthened the 8-hour ozone NAAQS by revising the primary 8-hour ozone standard to a level of 0.075 ppm. On March 6, 2015 (80 FR 12264), the EPA published a final rule for the implementation of the 2008 8-hour ozone NAAQS, while at the same time revoking the 1997 8-hour ozone NAAQS, effective on April 6, 2015. <SU>2</SU> <FTREF/> The EPA's previous approach, the 2008 8-hour ozone Implementation Rule established anti-backsliding principles to transition from implementing the revoked 1997 8-hour ozone NAAQS to the 2008 8-hour ozone NAAQS, the EPA clarified that RACT under the 1997 8-hour ozone NAAQS, among other requirements, continues to apply to a nonattainment area, in accordance with its designation and classification for the 1997 8-hour ozone NAAQS at the time of the revocation of the standard. Therefore, 1997 8-hour ozone RACT continues to be an applicable requirement for Philadelphia. <FTNT> <SU>2</SU>  “Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements” Final Rule, (80 FR 12264, March 6, 2015). </FTNT> <HD SOURCE="HD2">B. EPA's Requirements Under the 1997 8-Hour Ozone RACT</HD> On November 29, 2005 (70 FR 71612), the EPA published the Phase 2 Ozone Implementation Rule to address nonattainment SIP requirements for the 1997 8-hour ozone NAAQS. <SU>3</SU> <FTREF/> This rule addressed, among other things, control and planning obligations as they apply to nonattainment areas under the 1997 8-hour ozone NAAQS, including RACT and RACM. The EPA specifically required that States meet the RACT requirements, either through a certification that previously adopted RACT controls in their SIP revisions approved by the EPA under the 1-hour ozone NAAQS continue to represent adequate RACT control levels for 1997 8-hour ozone NAAQS attainment purposes, or through the adoption of new or more stringent regulations that represent RACT control levels. <SU>4</SU> <FTREF/> <FTNT> <SU>3</SU>  “Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard—Phase 2,” (70 FR 71612, November 29, 2005). </FTNT> <FTNT> <SU>4</SU>  For more information, see the preamble of the final Phase 2 Ozone Implementation Rule for a discussion of the EPA's interpretation of the CAA RACT requirements for the 1997 8-hour ozone NAAQS, in 70 FR 71652 through 71659 (November 29, 2005). </FTNT> <HD SOURCE="HD1">II. Summary of Proposed SIP Revision</HD> On October 7, 2016 (81 FR 69687), the EPA took final action to approve SIP revisions that were submitted by PADEP on behalf of AMS in order to satisfy RACT requirements of the 1997 ozone NAAQS applicable to sources located in Philadelphia. Included in that approval were source-specific requirements applicable to three 295 horsepower Caterpillar engines located at PGW Richmond. Specifically, Condition 1(B)(2) of AMS' July 9, 2015 RACT Plan Approval required that the timing of the engines be set and maintained at four degrees retarded relative to the standard timing. <SU>5</SU> <FTREF/> <FTNT> <SU>5</SU>  PGW RACT Plan Approval, 1/9/2015. </FTNT> On September 7, 2023, PADEP submitted to the EPA for approval, a SIP package that contains a revision to Pennsylvania's SIP to amend the source-specific RACT requirements for PGW Richmond by removing condition 1(B)(2). In this submittal, PADEP indicated that Condition 1(B)(2) was mistakenly included in the RACT Plan Approval for PGW Richmond. 25 Pennsylvania Code (Pa. Code) 129.93(c) contains a list of source types that are required to meet RACT through the “. . . installation, maintenance and operation of the source in accordance with manufacturers specifications.” Condition 1(B)(2) appears to have been included in order to constrain the engines in such a way that they would be subject to the presumptive RACT requirements of 25 Pa. Code 129.93(c). However, the engines as installed did not have timing as described in 25 Pa. Code 129.93(c)(3). Modifying the timing to 4 degrees retarded relative to standard timing would damage the engines and would be contrary to the presumptive RACT requirement the condition was intended to meet ( <E T="03">i.e.,</E> installation in accordance with manufacturers specifications). Furthermore, based on the permitted use of the three Caterpillar Engines 135GU 295 horsepower Units at PGW Richmond, AMS determined that the three emission units meet the criteria of 25 Pa. Code 129.93(c)(5), and are therefore still subject to the presumptive RACT requirem ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 14k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━