New Source Performance Standards Review for Stationary Combustion Turbines and Stationary Gas Turbines; Correction

ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 60 [EPA-HQ-OAR-2024-0419; FRL-11542.1-02-OAR] New Source Performance Standards Review for Stationary Combustion Turbines and Stationary Gas Turbines; Correction AGENCY: Environmental Protection Agency (EPA). ACTION: Correcting amendments. SUMMARY: The U.S. Environmental Protection Agency (EPA) is making corrections to the New Source Performance Standards Review for Stationary Combustion Turbines and Stationary Gas Turbines final rule (“Final NSPS Rule”) that published in the Federal Register (FR) on January 15, 2026, and became effective on January 15, 2026. After publication, the EPA identified inadvertent technical and typographical errors in the Federal Register regulatory text and is correcting those errors. DATES: Effective on August 17, 2026. ADDRESSES: The EPA established a docket for this action under Docket ID No. EPA-HQ-OAR-2024-0419. The docket lists all documents at https://www.regulations.gov. Although listed, some information is not publicly available, e.g., Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The EPA does not place certain other material, such as copyrighted material, on the internet; this material is publicly available only as portable document format (PDF) versions accessible only on EPA computers in the docket office reading room. The public cannot download certain databases and physical items from the docket but may request these items by contacting the docket office at (202) 566-1744. The docket office has 10 business days to respond to such requests. With the exception of such material, publicly available docket materials are available electronically at https://www.regulations.gov or on EPA computers in the docket office reading room at the EPA Docket Center, WJC West Building, Room Number 3334, 1301 Constitution Ave. NW, Washington, DC. The Public Reading Room hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Time (ET), Monday through Friday (except Federal holidays). The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the EPA Docket Center is (202) 566-1742. FOR FURTHER INFORMATION CONTACT: For information about this action, contact U.S. EPA, Attn.: John Ashley, Industrial Processing and Power Division (D243-02), 109 T.W. Alexander Drive, P.O. Box 12055, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-1458; and email address: ashley.john@epa.gov. SUPPLEMENTARY INFORMATION: The EPA is correcting the Final NSPS Rule, New Source Performance Standards Review for Stationary Combustion Turbines and Stationary Gas Turbines, which was published in the Federal Register at 91 FR 1910 on January 15, 2026. Following publication of this document, the EPA identified inadvertent technical and typographical errors in the regulatory text of new 40 Code of Federal Regulations (CFR) part 60, subpart KKKKa (“Subpart KKKKa”), as well as regulatory text amended by the Final NSPS Rule in existing 40 CFR part 60, subparts KKKK and GG (“Subpart KKKK” and “Subpart GG,” respectively). With this action, the EPA is correcting the following errors in FR Document Number (FR Doc) 2026-00677 and appearing at 91 FR 1910 in the Federal Register of January 15, 2026: • At 91 FR 1975, third column, 40 CFR part 60, subpart GG. Final NSPS Rule instruction 3 amended § 60.330 by revising paragraph (a) and adding paragraphs (c) through (e). The EPA corrects the regulatory text in paragraph (e) to read as being applicable to a “gas turbine” instead of a “combustion turbine.” The EPA is making this correction for consistency with Subpart GG, which applies to the stationary gas turbines source category. • At 91 FR 1978, third column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 9 amended § 60.4305 by revising paragraphs (a) and (b) and adding paragraphs (c) through (e). The EPA corrects the regulatory text in paragraph (e) to read as being applicable to “combustion turbines” instead of “stationary gas turbines.” The EPA is making this correction for consistency with Subpart KKKK, which applies to the stationary combustion turbines source category. In addition, the EPA removes the word “stationary” from the same phrase in paragraph (e) because turbines subject to title II of the Clean Air Act (CAA) are not stationary sources. • At 91 FR 1979, second column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 14 added § 60.4331. In § 60.4331 paragraphs (a) through (e), the EPA listed the requirements for operating a stationary temporary combustion turbine. The EPA corrects paragraph (a) to add the phrases “owners or operators of” and “may elect to be a temporary combustion turbine and” in the first sentence. These additions are necessary to clarify that the stationary temporary combustion turbine subcategory is optional for qualifying combustion turbines. Furthermore, the EPA adds the phrase “as an alternative to the otherwise applicable emission standards and monitoring, recordkeeping, and reporting requirements of this subpart” to the end of paragraph (a) to clarify that only those that elect to own or operate a stationary temporary combustion turbine must comply with the requirements in paragraphs (b) through (e) of this section. As conforming edits, the EPA deletes the phrases “you may operate,” “so long as you,” and “all of” from paragraph (a). In paragraph (c) introductory text and paragraph (d), the EPA deletes the phrase “Unless you elect to demonstrate compliance through the otherwise applicable monitoring, recordkeeping, and reporting requirements of this subpart” because this notice adds that phrase to paragraph (a). The EPA adds the word “combustion” before “turbine” in the first sentence of paragraph (e)(1) for consistency. • At 91 FR 1982, third column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 23 amended § 60.4380 by revising paragraph (b)(3). The EPA corrects the regulatory text in paragraph (b)(3) to reflect the use of an arithmetic average to determine the applicable nitrogen oxide (NO X ) standard for averaging periods during which multiple NO X emission standards apply. The Final NSPS Rule inadvertently incorporated regulatory text from Subpart KKKKa that specified the use of a heat input weighted average. • At 91 FR 1982, third column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 24 amended § 60.4395 by revising the introductory text. The EPA corrects the heading of this section to read “When must I submit my reports?” instead of “What must I submit my reports?” • At 91 FR 1984, third column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 28 amended § 60.4420 by adding and revising certain definitions. The EPA is making an editorial change to the last sentence of the “stationary combustion turbine” definition. The EPA adds the word “combustion” before the word “turbine” for consistency and moves the phrase “all related requirements” to before the phrase “promulgated pursuant to title II of the Clean Air Act” for grammatical correctness. • At 91 FR 1985, table 1, second column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 29 amended Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines. In the second column of the table, “Combustion turbine heat input at peak load (HHV),” the EPA amended the threshold for the subcategories of “Turbines located north of the Arctic Circle (latitude 66.5 degrees north), turbines operating at less than 75 percent of peak load, modified and reconstructed offshore turbines, and turbines operating at temperatures less than 0 °F.” Specifically, the EPA amended the size threshold for these subcategories by including a heat input-based threshold of 300 million British thermal units per hour (MMBtu/h) in addition to the existing 30 megawatts (MW) output-based threshold. The EPA is making a technical correction to revert to the 30 MW output-based threshold in Subpart KKKKa. As a conforming edit and for consistency across the subparts, the EPA revises table 1 of Subpart KKKK by reverting to the previous output-based threshold of 30 MW alone for these subcategories of turbines. Because the EPA retained the 30 MW metric as part of the size threshold in Subpart KKKK in the Final NSPS Rule, this change in Subpart KKKK has no practical effect. All combustion turbines with outputs greater than 30 MW also have base load ratings of greater than 300 MMBtu/h, so the added 300 MMBtu/h metric had no applicability implications. • At 91 FR 1985, table 1, first column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 29 amended Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines. In the last row of the table, the EPA added a subcategory for “Combustion turbines bypassing the heat recovery unit.” The EPA adds the phrase “firing natural gas” to the first column of this row. The EPA is making this correction for consistency with the previous applicable emission standards for units firing non-natural gas fuels in Subpart KKKK. The EPA restores those previous emission standards in Subpart KKKK by clarifying that this subcategory's NO X emission standard applies only to units firing natural gas. • At 91 FR 1985, table 1, first column, 40 CFR part 60, subpart KKKK. Final NSPS Rule instruction 29 amended Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines. The EPA corrects an omission from the table and lists subcategories for stationary temporary combustion turbines firing natural gas and firing fuels other than natural gas. These additional rows at the end of the table include the associated NO X emission standards for these subcategories, consistent with the discussion in the preamble at 91 FR 1925. The Final NSPS Rule inadvertently omitted these rows. • At 91 FR 1986, second column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4310a paragraph (d), the EPA identified “stationary gas turbines” as not being subject to this subpart if they are subject to title II of the CAA. The EPA corrects paragraph (d) to read as being applicable to “combustion turbines” instead of “stationary gas turbines.” The EPA is making this correction for consistency with Subpart KKKKa, which applies to the stationary combustion turbines source category. In addition, the EPA removes the word “stationary” from the same phrase in paragraph (d) because turbines subject to title II of the CAA are not stationary sources. • At 91 FR 1987, third column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4331a paragraphs (a) through (e), the EPA listed the requirements for operating a stationary temporary combustion turbine. The EPA corrects paragraph (a) to add the phrases “owners or operators of” and “may elect to be a temporary combustion turbine and” in the first sentence. This addition is necessary to clarify that the stationary temporary combustion turbine subcategory is optional for qualifying combustion turbines. Furthermore, the EPA adds the phrase “as an alternative to the otherwise applicable emission standards and monitoring, recordkeeping, and reporting requirements of this subpart” to the end of paragraph (a) to clarify that only those that elect to own or operate a stationary temporary combustion turbine must comply with the requirements in paragraphs (b) through (e) of this section. As conforming edits, the EPA deletes the phrases “you may operate,” “so long as you,” and “all of” from paragraph (a). In paragraph (c) introductory text and paragraph (d), the EPA deletes the phrase “Unless you elect to demonstrate compliance through the otherwise applicable monitoring, recordkeeping, and reporting requirements of this subpart” because this notice adds that phrase to paragraph (a). The EPA adds the word “combustion” before “turbine” in the first sentence of paragraph (e)(1) for consistency. • At 91 FR 1988, second column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4333a paragraph (b)(1), the EPA listed the general requirements for complying with the NO X emission standards. In paragraph (b)(1), the EPA corrects the stated interval between performance tests to 14-calendar-months instead of 12-calendar-months. The EPA is making this correction to align performance testing requirements in paragraph (b)(1) with the Agency's response to public comments, which states, “The language in 40 CFR 60.4333a(b) has been updated to be consistent with the 14- and 26-calendar-month testing gaps prescribed in subpart KKKK.”  1 1  See the document “Summary of Public Comments and Responses: Review of New Source Performance Standards for Stationary Combustion Turbines and Stationary Gas Turbines,” Section 8.5.2 Continuous emission monitoring, available in the docket (EPA Docket ID No. EPA-HQ-OAR-2024-0419) for this rulemaking at https://www.regulations.gov. • At 91 FR 1989, first column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4333a paragraph (d)(3), the EPA listed the methods that an owner or operator of a stationary combustion turbine must use to demonstrate compliance with a sulfur dioxide (SO 2 ) emission standard. The Final NSPS Rule inadvertently omitted a reference to § 60.4372a, which contains the additional acceptable method of using fuel records of the total sulfur content for the combusted fuel to demonstrate compliance. The EPA corrects the last sentence of § 60.4333a paragraph (d)(3) by adding a reference to § 60.4372a to clarify—consistent with the intent of the Final NSPS Rule—that maintaining records is an option for demonstrating compliance with the applicable SO 2 emission standard. • At 91 FR 1991, third column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4350a, the EPA listed instructions for determining excess NO X emissions using continuous emission monitoring system (CEMS) data. In § 60.4350a paragraph (d), the EPA explained the proper procedure for estimating emissions for hours with missing data. The EPA adds the phrase “of this chapter” after “part 75” in the first sentence of paragraph (d) for consistency. In addition, the EPA replaces the phrase “of the hour of” in the second sentence with “of the hourly load value of” after “± 10 percent.” The EPA is making this change to clarify the proper procedure for estimating emissions. • At 91 FR 1992, third column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4350a paragraph (f)(1), the EPA provided equation 1 for calculating the hourly average NO X emissions rate, including a list that defines the variables used in the equation. For variable T, the second sentence describes a calculation that “consists of useful thermal output on an annual basis.” The EPA corrects this description to clarify that variable T “consists of useful thermal output on a 12-calendar-month basis” instead of an “annual” basis, which could be confused with calendar-years. The EPA is making this change for consistency with the intent of the Final NSPS Rule, which bases emissions standards on a 12-calendar-month rolling average. • At 91 FR 1995, third column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4374a paragraph (g)(2), the EPA provided equation 2 for calculating the hourly average NO X emissions rate, including a list that defines the variables used in the equation. For variable T, the second sentence describes a calculation that “consists of useful thermal output on an annual basis.” The EPA corrects this description to clarify that variable T “consists of useful thermal output on a 12-calendar-month basis” instead of an “annual” basis, which could be confused with calendar-years. The EPA is making this change for consistency with the intent of Final NSPS Rule, which bases emissions standards on a 12-calendar-month rolling average. • At 91 FR 2000, first column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4400a, the EPA listed instructions for conducting performance tests to demonstrate compliance with the NO X emissions standards without using a NO X CEMS. The EPA corrects paragraph (d) introductory text to specify that owners or operators must conduct the performance test at any load condition within ± 30 percent of 100 percent of the base load rating and may perform testing at the highest achievable load point if they cannot achieve at least 70 percent of the base load rating in practice. The percentages listed in paragraph (d) introductory text of the Final NSPS Rule inadvertently included ± 25 percent and 75 percent from Subpart KKKK. Subpart KKKKa defines “full load” as greater than or equal to 70 percent of the base load rating of the turbine. Therefore, the correct percentages are “± 30 percent” instead of “± 25 percent” and “70 percent” instead of “75 percent.” The EPA makes the same corrections to § 60.4400a paragraph (d)(2). • At 91 FR 2000, second column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4405a, the EPA listed instructions for conducting performance tests to demonstrate compliance with the NO X emissions standards using a NO X CEMS. The EPA corrects paragraph (b)(1) to specify that owners or operators must conduct the performance test at a single load level, within ± 30 percent of 100 percent of the base load rating, and owners or operators may perform testing at the highest achievable load point if they cannot achieve at least 70 percent of the base load rating in practice. The percentages listed in paragraph (b)(1) of the Final NSPS Rule inadvertently included ± 25 percent and 75 percent from Subpart KKKK. Subpart KKKKa defines “full load” as greater than or equal to 70 percent of the base load rating of the turbine. Therefore, the correct percentages are “± 30 percent” instead of “± 25 percent” and “70 percent” instead of “75 percent.” • At 91 FR 2000, third column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4415a paragraph (a) and paragraph (b) introductory text, the EPA listed instructions for owners or operators to conduct performance tests to demonstrate compliance with the SO 2 emissions standard. The EPA corrects § 60.4415a paragraph (a) to clarify that “you may submit fuel records, . . .” instead of “must submit fuel records,” because using fuel records is not the only acceptable method of demonstrating compliance. Similarly, in § 60.4415a paragraph (b) introductory text, the EPA inadvertently omitted the phrase “and are not using fuel records, you . . .” Accordingly, the EPA corrects the introductory text to read: “If you are an owner or operator of an affected facility complying with the SO 2 emissions standard and are not using fuel records, you must conduct the performance test by measuring the SO 2 emissions in the stationary combustion turbine exhaust gases using the methods in either paragraph (b)(1) or (2) of this section.” • At 91 FR 2001, second column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Subpart KKKKa consisting of sections 60.4300a to 60.4420a. In § 60.4420a, the Final NSPS Rule included definitions that apply to this subpart. The EPA removes the definitions of “annual capacity factor,” “high-utilization source,” and “low-utilization source” because Subpart KKKKa does not use those terms. In addition, the EPA revises the definition of “gross energy output” in paragraph (3) to specify a “12-calendar-month” instead of an “annual” basis, the definition of “stationary combustion turbine” to move “all related requirements” before the phrase “promulgated pursuant to title II of the Clean Air Act” for grammatical correctness, and the definition of “turbine tuning” to clarify that Subpart KKKKa limits turbine tuning to 30 hours per 12-calendar-month period. The use of the phrase “12-calendar-month” instead of the word “annual” in the “gross energy output” and “turbine tuning” definitions is necessary to ensure consistency with the 12-calendar-month basis for emission standards and the intent of the Final NSPS Rule. Furthermore, the EPA adds the definition of “utilization” because that term is relevant for subcategorization purposes. • At 91 FR 2004, table 1, second column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Table 1 to Subpart KKKKa of Part 60—Nitrogen Oxide Emission Standards for Stationary Combustion Turbines. In the second column of the table, “Combustion turbine base load rated heat input (HHV),” the EPA set a heat-input threshold for the subcategories of turbines “Located north of the Arctic Circle (latitude 66.5 degrees north), operating at ambient temperatures less than 0 °F (-18 °C), modified or reconstructed offshore turbines, operated during periods of turbine tuning, byproduct-fired turbines, and/or operating at less than 70 percent of the base load rating.” Specifically, the EPA set the threshold for this subcategory as a heat input-based threshold of 300 MMBtu/h. The EPA intended for this threshold in Subpart KKKKa to be equivalent to the output-based threshold of 30 MW in Subpart KKKK. The EPA attempted to align the combustion turbine size subcategories in both subparts with heat input-based thresholds for associated NO X standards for consistency. 2 The EPA did not intend to effectuate a substantive change in the size threshold for these subcategories. 3 However, the EPA is now aware that these two forms of threshold are not equivalent for all combustion turbines in these subcategories that could be subject to Subpart KKKKa, and this change inadvertently substantively altered this threshold, which was not the Agency's intent. 4 Therefore, the EPA corrects this unintended error in table 1 to Subpart KKKKa by reverting to the output-based threshold of 30 MW in Subpart KKKK for these subcategories of turbines in Subpart KKKKa. 2   See 91 FR 1928 (January 15, 2026). 3   Id. 4  See the petition for reconsideration filed with the EPA by the American Petroleum Institute (API), available in the rulemaking docket under Docket ID # EPA-HQ-OAR-2024-0419-0246. It is the Agency's expectation that this correction fully resolves the issue raised in this petition for reconsideration. • At 91 FR 2004, table 1, first column, 40 CFR part 60, subpart KKKKa. Final NSPS Rule instruction 30 added Table 1 to Subpart KKKKa of Part 60—Nitrogen Oxide Emission Standards for Stationary Combustion Turbines. To better clarify the NO X emission standards applicable to stationary temporary combustion turbines consistent with the discussion in the preamble, 5 the EPA adds the subcategories of temporary turbines firing natural gas and temporary turbines firing fuels other than natural gas to the end of the table in separate rows. The EPA removes the reference to temporary turbines from the subcategory of “New, firing natural gas, either offshore turbines, turbines bypassing the heat recovery unit, and/or temporary turbines” as a conforming edit and inserts “and/or” before the phrase “turbines bypassing the heat recovery unit.” 5   See 91 FR 1925 (January 15, 2026). Section 553 of the Administrative Procedure Act provides that when an agency for good cause finds that notice and public procedure are impracticable, unnecessary, or contrary to the public interest, the agency may issue a rule without providing notice and an opportunity for public comment. 6 The EPA has determined that there is good cause for making this rule final without prior proposal and opportunity for comment because the changes to the rule are minor, noncontroversial in nature, and correct inadvertent typographical and technical errors. These changes align regulatory text with the EPA's expressed intent in the Final NSPS Rule preamble and do not substantively change the requirements of the Final NSPS Rule except to the extent necessary to align the regulatory text with the EPA's intent, which the preamble expressly states. Thus, the corrected regulatory text in this action has already had notice and opportunity for public comment, rendering further notice and opportunity for public comment unnecessary. The EPA finds that this constitutes good cause under 5 U.S.C. 553(b)(B). 6  5 U.S.C. 553(b)(B). List of Subjects in 40 CFR Part 60 Environmental protection, Administrative practice and procedures, Air pollution control, Reporting and recordkeeping requirements. Accordingly, 40 CFR part 60 is corrected by making the following correcting amendments: PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES 1. The authority citation for part 60 continues to read as follows: Authority: 42 U.S.C. 7401 et seq. Subpart GG—Standards of Performance for Stationary Gas Turbines 2. Amend § 60.330 by revising paragraph (e) to read as follows: § 60.330 Applicability and designation of affected facility. (e) A gas turbine that is subject to this subpart and is not a “major source” or located at a “major source” (as that term is defined at 42 U.S.C. 7661 (2)) is exempt from the requirements of 42 U.S.C. 7661a(a). Subpart KKKK—Standards of Performance for Stationary Combustion Turbines 3. Amend § 60.4305 by revising paragraph (e) to read as follows: § 60.4305 Does this subpart apply to my stationary combustion turbine? (e) Combustion turbines subject to title II of the Clean Air Act are not subject to this subpart. 4. Amend § 60.4331 by revising paragraph (a), paragraph (c) introductory text, and paragraphs (d) and (e)(1) to read as follows: § 60.4331 What are the requirements for operating a stationary temporary combustion turbine? (a) Notwithstanding any other provision of this subpart, owners or operators of a small- or medium-size stationary combustion turbine ( i.e., a combustion turbine with a base load rating less than or equal to 850 MMBtu/h) at a single location for up to 24 consecutive months, may elect to be a temporary combustion turbine and comply with the requirements in paragraphs (b) through (e) of this section as an alternative to the otherwise applicable emission standards and monitoring, recordkeeping, and reporting requirements of this subpart. (c) Compliance with the NO X emissions standard must be demonstrated through maintaining the documentation in paragraphs (c)(1) and (2) of this section on-site: (d) Compliance with the SO 2 emissions standard must be demonstrated through complying with the provisions in § 60.4365. (e) * * * (1) The combustion turbine may only be located at the same stationary source (or group of stationary sources located within a contiguous area and under common control) for a total period of 24 consecutive months. This is the total period of residence time allowed after the turbine commences operation at the location, regardless of whether the turbine is in operation for the entire 24-consecutive-month period. 5. Amend § 60.4380 by revising paragraph (b)(3) to read as follows: § 60.4380 How are excess emissions and monitor downtime defined for NO X ? (b) * * * (3) For averaging periods during which multiple emissions standards apply, the applicable standard for the averaging period is the arithmetic average of the applicable standards during each hour. For hours with multiple emission standards, the applicable standard for that hour is determined based on the condition that corresponded to the highest emissions standard. 6. Amend § 60.4395 by revising the section heading to read as follows: § 60.4395 When must I submit my reports? 7. Amend § 60.4420 by revising the definition of “Stationary combustion turbine” to read as follows: § 60.4420 What definitions apply to this subpart? Stationary combustion turbine means all equipment, including but not limited to the turbine, the fuel, air, lubrication and exhaust gas systems, control systems (except emissions control equipment), heat recovery system, and any ancillary components and sub-components comprising any simple cycle stationary combustion turbine, any regenerative/recuperative cycle stationary combustion turbine, any combined cycle combustion turbine, and any combined heat and power combustion turbine based system. Stationary means that the combustion turbine is not self-propelled or intended to be propelled while performing its function. It may, however, be mounted on a vehicle for portability. Portable combustion turbines are excluded from the definition of “stationary combustion turbine,” and not regulated under this part, if the combustion turbine meets the definition of “nonroad engine” under title II of the Clean Air Act and applicable regulations and is certified to meet emission standards and all related requirements promulgated pursuant to title II of the Clean Air Act. 8. Revise table 1 to subpart KKKK of part 60 to read as follows: Table 1 to Subpart KKKK of Part 60—Nitrogen Oxide Emission Limits for New Stationary Combustion Turbines Combustion turbine type Combustion turbine heat input at peak load (HHV) NO X emission standard New turbine firing natural gas, electric generating ≤50 MMBtu/h 42 ppm at 15 percent O 2 or 290 ng/J of useful output (2.3 lb/MWh). New turbine firing natural gas, mechanical drive ≤50 MMBtu/h 100 ppm at 15 percent O 2 or 690 ng/J of useful output (5.5 lb/MWh). New turbine firing natural gas >50 MMBtu/h and ≤850 MMBtu/h 25 ppm at 15 percent O 2 or 150 ng/J of useful output (1.2 lb/MWh). New, modified, or reconstructed turbine firing natural gas >850 MMBtu/h 15 ppm at 15 percent O 2 or 54 ng/J of useful output (0.43 lb/MWh). New turbine firing fuels other than natural gas, electric generating ≤50 MMBtu/h 96 ppm at 15 percent O 2 or 700 ng/J of useful output (5.5 lb/MWh). New turbine firing fuels other than natural gas, mechanical drive ≤50 MMBtu/h 150 ppm at 15 percent O 2 or 1,100 ng/J of useful output (8.7 lb/MWh). New turbine firing fuels other than natural gas >50 MMBtu/h and ≤850 MMBtu/h 74 ppm at 15 percent O 2 or 460 ng/J of useful output (3.6 lb/MWh). New, modified, or reconstructed turbine firing fuels other than natural gas >850 MMBtu/h 42 ppm at 15 percent O 2 or 160 ng/J of useful output (1.3 lb/MWh). Modified or reconstructed turbine ≤50 MMBtu/h 150 ppm at 15 percent O 2 or 1,100 ng/J of useful output (8.7 lb/MWh). Modified or reconstructed turbine firing natural gas >50 MMBtu/h and ≤850 MMBtu/h 42 ppm at 15 percent O 2 or 250 ng/J of useful output (2.0 lb/MWh). Modified or reconstructed turbine firing fuels other than natural gas >50 MMBtu/h and ≤850 MMBtu/h 96 ppm at 15 percent O 2 or 590 ng/J of useful output (4.7 lb/MWh). Turbines located north of the Arctic Circle (latitude 66.5 degrees north); turbines operating at less than 75 percent of peak load; modified and reconstructed offshore turbines; and turbines operating at temperatures less than 0 °F ≤30 MW output 150 ppm at 15 percent O 2 or 1,100 ng/J of useful output (8.7 lb/MWh). Turbines located north of the Arctic Circle (latitude 66.5 degrees north); turbines operating at less than 75 percent of peak load; modified and reconstructed offshore turbines; and turbines operating at temperatures less than 0 °F >30 MW output 96 ppm at 15 percent O 2 or 590 ng/J of useful output (4.7 lb/MWh). Heat recovery units operating independent of the combustion turbine All sizes 54 ppm at 15 percent O 2 or 110 ng/J of useful output (0.86 lb/MWh). Combustion turbines bypassing the heat recovery unit firing natural gas >50 MMBtu/h 25 ppm at 15 percent O 2 or 150 ng/J of useful output (1.2 lb/MWh). Temporary turbine firing natural gas ≤850 MMBtu/h 25 ppm at 15 percent O 2 or 150 ng/J of useful output (1.2 lb/MWh). Temporary turbine firing fuels other than natural gas ≤850 MMBtu/h 74 ppm at 15 percent O 2 or 460 ng/J of useful output (3.6 lb/MWh). Subpart KKKKa—Standards of Performance for Stationary Combustion Turbines 9. Amend § 60.4310a by revising paragraph (d) to read as follows: § 60.4310a What stationary combustion turbines are not subject to this subpart? (d) Combustion turbines subject to title II of the Clean Air Act are not subject to this subpart. 10. Amend § 60.4331a by revising paragraph (a), paragraph (c) introductory text, and paragraphs (d) and (e)(1) to read as follows: § 60.4331a What are the requirements for operating a stationary temporary combustion turbine? (a) Notwithstanding any other provision of this subpart, owners or operators of a small- or medium-size stationary combustion turbine ( i.e., a combustion turbine with a base load rating less than or equal to 850 MMBtu/h) at a single location for up to 24 consecutive months, may elect to be a temporary combustion turbine and comply with the requirements in paragraphs (b) through (e) of this section as an alternative to the otherwise applicable emission standards and monitoring, recordkeeping, and reporting requirements of this subpart. (c) Compliance with the NO X emissions standard must be demonstrated through maintaining the documentation in paragraphs (c)(1) and (2) of this section on-site: (d) Compliance with the SO 2 emissions standard must be demonstrated through complying with the provisions in § 60.4372a. (e) * * * (1) The combustion turbine may only be located at the same stationary source (or group of stationary sources located within a contiguous area and under common control) for a total period of 24 consecutive months. This is the total period of residence time allowed after the turbine commences operation at the location, regardless of whether the turbine is in operation for the entire 24-consecutive-month period. 11. Amend § 60.4333a by revising paragraphs (b)(1) and (d)(3) to read as follows: § 60.4333a What are my general requirements for complying with this subpart? (b) * * * (1) Except as provided for in paragraphs (b)(2) through (5) of this section, you must conduct subsequent performance tests within 14 calendar months of the date that the previous performance test was conducted. (d) * * * (3) Conduct an initial performance test according to § 60.8 and use the applicable methods in § 60.4415a. Thereafter, maintain records (such as a current, valid purchase contract, tariff sheet, or transportation contract) documenting that total sulfur content for the initial and subsequent fuel combusted in your stationary combustion turbine at all times does not exceed applicable conditions specified in § 60.4370a or § 60.4372a; or 12. Amend § 60.4350a by revising paragraph (d) and equation 1 to paragraph (f)(1) to read as follows: § 60.4350a How do I use the NO X CEMS data to determine excess emissions? (d) Data used to meet the requirements of this subpart shall not include substitute data values derived from the missing data procedures of part 75 of this chapter, nor shall the data be bias adjusted according to the procedures of part 75 of this chapter. For units complying with the 12-calendar-month mass-based standard, emissions for hours of missing data shall be estimated by using the average emissions rate of non-out-of-control hours within ±10 percent of the hourly load value of missing data within the 12-calendar-month period. If non-out-of-control data is not available, the maximum hourly emissions rate during the 12-calendar-month period shall be used. (f) * * * (1) * * * Equation 1 to Paragraph (f)(1) ER16JY26.505 Where: P = Gross or net energy output of the stationary combustion turbine system in MWh; (Pe) t = Electrical or mechanical energy output of the combustion turbine engine in MWh; (Pe) c = Electrical or mechanical energy output (if any) of the steam turbine in MWh; Pe A = Electric energy used for any auxiliary loads in MWh (only applicable to owners/operators electing to demonstrate compliance on a net output basis); P s = Useful thermal energy of the steam, measured relative to ISO conditions, not used to generate additional electric or mechanical output, in MWh; P o = Other useful heat recovery, measured relative to ISO conditions, not used for steam generation or performance enhancement of the stationary combustion turbine; and T = Electric Transmission and Distribution Factor. Equal to 0.95 for CHP combustion turbine where at least 20.0 percent of the total gross useful energy output consists of electric or direct mechanical output and 20.0 percent of the total gross useful energy output consists of useful thermal output on a 12-calendar-month basis. Equal to 1.0 for all other combustion turbines. 13. Amend § 60.4374a by revising equation 2 to paragraph (g)(2) to read as follows: § 60.4374a How do I demonstrate compliance with my SO 2 emissions standard and determine excess emissions using a SO 2 CEMS? (g) * * * (2) * * * Equation 2 to Paragraph (g)(2) ER16JY26.506 Where: P = Gross energy output of the stationary combustion turbine system in MWh; (Pe) t = Electrical or mechanical energy output of the stationary combustion turbine in MWh; (Pe) c = Electrical or mechanical energy output (if any) of the steam turbine in MWh; Pe A = Electric energy used for any auxiliary loads in MWh; P s = Useful thermal energy of the steam, measured relative to ISO conditions, not used to generate additional electric or mechanical output, in MWh; P o = Other useful heat recovery, measured relative to ISO conditions, not used for steam generation or performance enhancement of the stationary combustion turbine; and T = Electric Transmission and Distribution Factor. Equal to 0.95 for CHP combustion turbine where at least 20.0 percent of the total gross useful energy output consists of electric or direct mechanical output and 20.0 percent of the total gross useful energy output consists of useful thermal output on a 12-calendar-month basis. Equal to 1.0 for all other combustion turbines. 14. Amend § 60.4400a by revising paragraph (d) introductory text and paragraph (d)(2) to read as follows: § 60.4400a How do I conduct performance tests to demonstrate compliance with my NO X emissions standard if I do not have a NO X CEMS? (d) The performance test must be done at any load condition within ±30 percent of 100 percent of the base load rating. You may perform testing at the highest achievable load point, if at least 70 percent of the base load rating cannot be achieved in practice. You must conduct three separate test runs for each performance test. The minimum time per run is 20 minutes. (2) For a combined cycle or CHP combustion turbine with supplemental heat (duct burner), you must measure the total NO X emissions downstream of the duct burner. The duct burner must be in operation within ±30 percent of 100 percent of the base load rating of the duct burners or the highest achievable load if at least 70 percent of the base load rating of the duct burners cannot be achieved during the performance test. 15. Amend § 60.4405a by revising paragraph (b)(1) to read as follows: § 60.4405a How do I conduct a performance test if I use a NO X CEMS? (b) * * * (1) Perform a minimum of nine RATA reference method runs, with a minimum time per run of 21 minutes, at a single load level, within ±30 percent of 100 percent of the base load rating while the source is combusting the fuel that is a normal primary fuel for that source. You may perform testing at the highest achievable load point, if at least 70 percent of the base load rating cannot be achieved in practice. The ambient temperature must be greater than 0 °F during the RATA runs. The Administrator or delegated authority may approve performance testing below 0 °F if the timing of the required performance test and environmental conditions make it impractical to test at ambient conditions greater than 0 °F. 16. Amend § 60.4415a by revising paragraph (a) and paragraph (b) introductory text to read as follows: § 60.4415a How do I conduct performance tests to demonstrate compliance with my SO 2 emissions standard? (a) If you are an owner or operator of an affected facility complying with the fuel-based standard, you may submit fuel records (such as a current, valid purchase contract, tariff sheet, transportation contract, or results of a fuel analysis) to satisfy the requirements of § 60.8. (b) If you are an owner or operator of an affected facility complying with the SO 2 emissions standard and are not using fuel records, you must conduct the performance test by measuring the SO 2 emissions in the stationary combustion turbine exhaust gases using the methods in either paragraph (b)(1) or (2) of this section. 17. Amend § 60.4420a by: a. Removing the definition of “Annual capacity factor”; b. Revising the definition of “Gross energy output”; c. Removing the definitions of “High-utilization source” and “Low-utilization source”; d. Revising the definitions of “Stationary combustion turbine” and “Turbine tuning”; and e. Adding the definition of “Utilization” in alphabetical order. The revisions and addition read as follows: § 60.4420a What definitions apply to this subpart? Gross energy output means: (1) For simple cycle and combined cycle combustion turbines, the gross useful work performed is the gross electrical or direct mechanical output from both the combustion turbine engine and any associated steam turbine(s). (2) For a CHP combustion turbine, the gross useful work performed is the gross electrical or direct mechanical output from both the combustion turbine engine and any associated steam turbine(s) plus any useful thermal output measured relative to ISO conditions that is not used to generate additional electrical or mechanical output or to enhance the performance of the unit ( i.e., steam delivered to an industrial process). (3) For a CHP combustion turbine where at least 20.0 percent of the total gross useful energy output consists of useful thermal output on a 12-calendar-month basis, the gross useful work performed is the gross electrical or direct mechanical output from both the combustion turbine engine and any associated steam turbine(s) divided by 0.95 plus any useful thermal output measured relative to ISO conditions that is not used to generate additional electrical or mechanical output or to enhance the performance of the unit ( i.e., steam delivered to an industrial process). (4) For a district energy CHP combustion turbine where at least 20.0 percent of the total gross useful energy output consists of useful thermal output on a 12-calendar-month basis, the gross useful work performed is the gross electrical or direct mechanical output from both the combustion turbine engine and any associated steam turbine(s) divided by 0.95 plus any useful thermal output measured relative to ISO conditions that is not used to generate additional electrical or mechanical output or to enhance the performance of the unit ( e.g., steam delivered to an industrial process) divided by 0.95. Stationary combustion turbine means all equipment including, but not limited to, the combustion turbine engine, the fuel, air, lubrication and exhaust gas systems, control systems (except post combustion emissions control equipment), heat recovery system (including heat recovery steam generators and duct burners); steam turbine; fuel compressor and/or pump, any ancillary components and sub-components comprising any simple cycle stationary combustion turbine, any combined cycle combustion turbine, and any combined heat and power combustion turbine based system; plus any integrated equipment that provides electricity or useful thermal output to the combustion turbine engine ( e.g., onsite photovoltaics), heat recovery system, or auxiliary equipment. Stationary means that the combustion turbine is not self-propelled or intended to be propelled while performing its function. It may, however, be mounted on a vehicle for portability. Portable combustion turbines are excluded from the definition of “stationary combustion turbine,” and not regulated under this part, if the combustion turbine meets the definition of “nonroad engine” under title II of the Clean Air Act and applicable regulations and is certified to meet emissions standards and all related requirements promulgated pursuant to title II of the Clean Air Act. Turbine tuning means planned maintenance or parameter performance testing of a combustion turbine engine involving adjustment of the operating configuration to maintain proper combustion dynamics or testing machine operating performance. Turbine tuning is limited to 30 hours per 12-calendar-month period. Utilization means the ratio between the actual heat input to a combustion turbine engine (not including any heat input to an HRSG) during a 12-calendar-month period and the potential heat input to the combustion turbine engine had it operated at the base load rating for every hour during the 12-calendar-month period. Heat input during a system emergency as defined in this section is excluded when determining the utilization rate. Actual and potential heat input derived from non-combustion sources ( e.g., solar thermal) are not included when calculating the utilization. 18. Revise table 1 to subpart KKKKa of part 60 to read as follows: Table 1 to Subpart KKKK a of Part 60—Nitrogen Oxide Emission Standards for Stationary Combustion Turbines Combustion turbine type Combustion turbine base load rated heat input (HHV) Input-based NO X emission standard  1 Optional output-based NO X standard  2 New, firing natural gas with utilization rate >45 percent >850 MMBtu/h 5 ppm at 15 percent O 2 or 7.9 ng/J (0.018 lb/MMBtu) 0.054 kg/MWh-gross (0.12 lb/MWh-gross) 0.055 kg/MWh-net (0.12 lb/MWh-net). New, firing natural gas with utilization rate ≤45 percent and with design efficiency ≥38 percent >850 MMBtu/h 25 ppm at 15 percent O 2 or 40 ng/J (0.092 lb/MMBtu) 0.38 kg/MWh-gross (0.83 lb/MWh-gross) 0.39 kg/MWh-net (0.85 lb/MWh-net). New, firing natural gas with utilization rate ≤45 percent and with design efficiency <38 percent >850 MMBtu/h 9 ppm at 15 percent O 2 or 14 ng/J (0.033 lb/MMBtu) 0.17 kg/MWh-gross (0.37 lb/MWh-gross) 0.17 kg/MWh-net (0.38 lb/MWh-net). New, modified, or reconstructed, firing non-natural gas >850 MMBtu/h 42 ppm at 15 percent O 2 or 70 ng/J (0.16 lb/MMBtu) 0.45 kg/MWh-gross (1.0 lb/MWh-gross) 0.46 kg/MWh-net (1.0 lb/MWh-net). Modified or reconstructed, firing natural gas, at all utilization rates, with design efficiency ≥38 percent >850 MMBtu/h 25 ppm at 15 percent O 2 or 40 ng/J (0.092 lb/MMBtu) 0.38 kg/MWh-gross (0.83 lb/MWh-gross) 0.39 kg/MWh-net (0.85 lb/MWh-net). Modified or reconstructed, firing natural gas, at all utilization rates, with design efficiency <38 percent >850 MMBtu/h 15 ppm at 15 percent O 2 or 24 ng/J (0.055 lb/MMBtu) 0.28 kg/MWh-gross (0.62 lb/MWh-gross) 0.29 kg/MWh-net (0.30 lb/MWh-net). New, firing natural gas, at utilization rate >45 percent >50 MMBtu/h and ≤850 MMBtu/h 15 ppm at 15 percent O 2 or 24 ng/J (0.055 lb/MMBtu) 0.20 kg/MWh-gross (0.43 lb/MWh-gross) 0.20 kg/MWh-net (0.44 lb/MWh-net). New, firing natural gas, at utilization rate ≤45 percent >50 MMBtu/h and ≤850 MMBtu/h 25 ppm at 15 percent O 2 or 40 ng/J (0.092 lb/MMBtu) 0.54 kg/MWh-gross (1.2 lb/MWh-gross) 0.56 kg/MWh-net (1.2 lb/MWh-net). Modified or reconstructed, firing natural gas >20 MMBtu/h and ≤850 MMBtu/h 42 ppm at 15 percent O 2 or 67 ng/J (0.15 lb/MMBtu) 0.91 kg/MWh-gross (2.0 lb/MWh-gross) 0.92 kg/MWh-net (2.0 lb/MWh-net). New, firing non-natural gas >50 MMBtu/h and ≤850 MMBtu/h 74 ppm at 15 percent O 2 or 120 ng/J (0.29 lb/MMBtu) 1.6 kg/MWh-gross (3.6 lb/MWh-gross) 1.6 kg/MWh-net (3.7 lb/MWh-net). Modified or reconstructed, firing non-natural gas >20 MMBtu/h and ≤850 MMBtu/h 96 ppm at 15 percent O 2 or 160 ng/J (0.37 lb/MMBtu) 2.1 kg/MWh-gross (4.7 lb/MWh-gross) 2.2 kg/MWh-net (4.8 lb/MWh-net). New, firing natural gas ≤50 MMBtu/h 25 ppm at 15 percent O 2 or 40 ng/J (0.092 lb/MMBtu) 0.64 kg/MWh-gross (1.4 lb/MWh-gross) 0.65 kg/MWh-net (1.4 lb/MWh-net). New, firing non-natural gas ≤50 MMBtu/h 96 ppm at 15 percent O 2 or 160 ng/J (0.37 lb/MMBtu) 2.4 kg/MWh-gross (5.3 lb/MWh-gross) 2.5 kg/MWh-net (5.4 lb/MWh-net). Modified or reconstructed, all fuels ≤20 MMBtu/h 150 ppm at 15 percent O 2 or 240 ng/J (0.55 lb/MMBtu) 3.9 kg/MWh-gross (8.7 lb/MWh-gross) 4.0 kg/MWh-net (8.9 lb/MWh-net). New, firing natural gas, either offshore turbines and/or turbines bypassing the heat recovery unit >50 MMBtu/h 25 ppm at 15 percent O 2 or 40 ng/J (0.092 lb/MMBtu) N/A. Located north of the Arctic Circle (latitude 66.5 degrees north), operating at ambient temperatures less than 0 °F (−18 °C),