Air Plan Approval; New Hampshire; Reasonable Available Control Technology for the 2008 and 2015 Ozone Standards

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R01-OAR-2023-0188; FRL-11025-03-R1]</DEPDOC> <SUBJECT>Air Plan Approval; New Hampshire; Reasonable Available Control Technology for the 2008 and 2015 Ozone Standards</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is approving State Implementation Plan (SIP) revisions submitted by the State of New Hampshire. The revisions establish NO <E T="52">X</E> reasonably available control technology (RACT) requirements for coal-fired cyclone boilers located in the state, portions of New Hampshire's NO <E T="52">X</E> RACT certifications for the 2008 and 2015 ozone standards that pertain to requirements for coal-fired cyclone boilers, and withdrawal from the SIP of two previously issued RACT orders. This action is being taken in accordance with the Clean Air Act (CAA). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective on May 30, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket Identification No. EPA-R01-OAR-2023-0188. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">i.e.,</E> 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 at <E T="03">https://www.regulations.gov</E> or at the U.S. Environmental Protection Agency, EPA Region 1 Regional Office, Air and Radiation Division, 5 Post Office Square—Suite 100, Boston, MA. EPA requests that if at all possible, you contact the contact listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding legal holidays and facility closures due to COVID-19. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Bob McConnell, Environmental Engineer, Air and Radiation Division (Mail Code 5-MD), U.S. Environmental Protection Agency, Region 1, 5 Post Office Square, Suite 100, Boston, Massachusetts, 02109-3912; (617) 918-1046; <E T="03">mcconnell.robert@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. Background and Purpose</FP> <FP SOURCE="FP-2">II. Response to Comments</FP> <FP SOURCE="FP-2">III. Final Action</FP> <FP SOURCE="FP-2">IV. Incorporation by Reference</FP> <FP SOURCE="FP-2">V. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Background and Purpose</HD> On July 10, 2023 (88 FR 43483), EPA published a Notice of Proposed Rulemaking (NPRM) for the State of New Hampshire. The NPRM proposed to determine that the State has adopted regulations meeting the requirements for reasonably available control technology (RACT) for the 2008 and 2015 ozone national ambient air quality standards (NAAQS), to approve amendments to a related regulation that New Hampshire revised as part of its RACT certifications for these two NAAQS, to approve a revision to the State's definition of emergency generator, and removal from the SIP of two previously issued RACT orders affecting coal-fired cyclone boilers operated by Merrimack Station located in Bow, New Hampshire. EPA received a comment letter from the Sierra Club dated August 9, 2023, that opposed New Hampshire's NO <E T="52">X</E> RACT limits applicable to coal-fired cyclone boilers. We approved the portions of the proposal unaffected by this comment letter in a final rule published on September 6, 2023 (88 FR 60893). In this final rule, we are approving the remaining portions of these SIP revisions, which include requirements within New Hampshire's Env-A 1300 establishing RACT requirements for coal-fired electrical cyclone boilers, the portions of New Hampshire's NO <E T="52">X</E> RACT certifications for the 2008 and 2015 ozone standards that pertain to requirements for coal-fired cyclone boilers, and we are taking final action to withdraw from the New Hampshire SIP two RACT orders that contain less stringent requirements for cyclone boilers. Please see our July 10, 2023 proposed rule for additional background and a more detailed explanation of our proposed action. <HD SOURCE="HD1">II. Response to Comments</HD> As mentioned, we received one comment letter on our July 10, 2023 proposed approval, which was from the Sierra Club and expressed opposition to the proposed approval of New Hampshire's (NH's) NO <E T="52">X</E> RACT requirements applicable to the coal-fired cyclone boilers operated by Granite Shore Power at its Merrimack Station electrical generating facility located in Bow. Our responses to the comments raised by Sierra Club appear below. <E T="03">Comment:</E> Sierra Club commented that the emission rate of 0.22 lbs/MMBtu for two coal-fired cyclone boilers at Merrimack Station, herein referred to as units MK1 and MK2, is inadequate as RACT. Sierra Club commented that, since 2018, MK1 and MK2 consistently demonstrated the ability to meet a 24-hour average emission rate at or below 0.20 lbs/MMBtu, which is 10% lower than NH's emissions limit of 0.22 lbs/MMBtu, and thereby asserted that the state's limit is too lenient. <E T="03">Response:</E> New Hampshire developed its NO <E T="52">X</E> RACT emissions limits for MK1 and MK2 in consideration of a number of factors. One such factor was the observation that the selected emissions limit of 0.22 lbs NO <E T="52">X</E> /MMBtu represented emission reductions of 83% and 91% from uncontrolled levels for MK1 and MK2, respectively, <SU>1</SU> <FTREF/> which is a high level of control. Given MK2's larger size and emissions, the emissions weighted average reduction from uncontrolled levels for both units combined is 88% based on emissions data for 2022. This level of control is near the upper end of the emission reduction capability of selective catalytic reduction (SCR) control systems as noted within EPA control technology explanatory materials, such as the agency's fact sheet on SCR NO <E T="52">X</E> control technology, which indicates a control range of between 70-90% is achievable from such systems. <SU>2</SU> <FTREF/> Additionally, correspondence dated May 25, 2018 from the facility owner, Granite Shore Power, to the New Hampshire DES indicated that a more restrictive normal operating mode emission rate of 0.20 lbs/MMBtu on a 24-hr basis that was originally considered by NH DES was beyond the original emission reduction control capability of the units when they were newly installed. Granite Shore Power reiterated this point in a January 17, 2020 correspondence to the New Hampshire DES concerning regional haze requirements in which they note that the revised NO <E T="52">X</E> RACT limits “represent the most effective use of the SCR, given that the system must be operated year round at or above its design capacity to demonstrate compliance.” <FTNT> <SU>1</SU>  NH based its emission reduction calculations on the uncontrolled levels observed during stack tests for MK1 and MK2. </FTNT> <FTNT> <SU>2</SU>  Air Pollution Control Technology Fact Sheet: Selective Catalytic Reduction (SCR); EPA-452/F-03-032. </FTNT> In 2018 as New Hampshire was developing its NO <E T="52">X</E> RACT emissions limit for MK1 and MK2, the state reviewed the emissions data from the continuous emissions monitoring systems (CEMS) on the units collected in 2000, when the equipment was newly installed, through 2007. Merrimack Station installed a second SCR control unit in 1999 due to the Ozone Transport Region (OTC) NO <E T="52">X</E> budget program. Previously only one of the Merrimack Station units had SCR, installed circa 1995. This period of time coincides with the period of time that Electric Generating Units (EGUs) in New Hampshire had new emission control obligations under the OTC's NO <E T="52">X</E> Budget program. <SU>3</SU> <FTREF/> This program began in 1999 and continued through 2002, at which point most of the EGUs transitioned to the EPA's first ozone season NO <E T="52">X</E> control program, that being the NO <E T="52">X</E> SIP Call. <SU>4</SU> <FTREF/> Although EGUs in New Hampshire were not required to participate in the EPA's NO <E T="52">X</E> SIP Call program, New Hampshire maintained, as an anti-backsliding measure, the OTC NO <E T="52">X</E> Budget program's ozone season cap for sources located in the state, including MK1 and MK2, beyond 2002. EPA facilitated oversight of New Hampshire's post-2002 NO <E T="52">X</E> Budget program by creating a separate account referred to as the “NH NO <E T="52">X</E> Program” on its Clean Air Markets Program Data (CAMPD) website. <SU>5</SU> <FTREF/> <FTNT> <SU>3</SU>  EPA approved the program New Hampshire developed to comply with the OTC's NO <E T="52">X</E> Budget program into the NH SIP on November 14, 2000 (see 65 FR 68078). </FTNT> <FTNT> <SU>4</SU>  See EPA's October 27, 1998, (63 FR 57356) final rulemaking action known as the NO <E T="52">X</E> SIP Call. </FTNT> <FTNT> <SU>5</SU>  The NO <E T="52">X</E> emissions data for the New Hampshire's EGU's, including MK1 and MK2, are still maintained on the CAMPD website by retrieving data under the program name “NH NO <E T="52">X</E> Program”. </FTNT> New Hampshire's selection of 0.22 lbs NO <E T="52">X</E> /MMBtu, to be ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 51k characters. 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