(a) Definitions. All terms not defined in this paragraph (a) shall have the meaning given to them in the Act and in subpart A of 40 CFR part 60.

Affected unit means any reheat furnace meeting the applicability criteria of this section.

Day means a calendar day unless expressly stated to be a business day. In computing any period of time for recordkeeping and reporting purposes where the last day would fall on a Saturday, Sunday, or Federal holiday, the period shall run until the close of business of the next business day.

Low NOX burner means a burner designed to reduce flame turbulence by the mixing of fuel and air and by establishing fuel-rich zones for initial combustion, thereby reducing the formation of NOX.

Low-NOX technology means any post-combustion NOX control technology capable of reducing NOX emissions by 40% from baseline emission levels as measured during pre-installation testing.

Operating day means a 24-hour period beginning at 12:00 midnight during which any fuel is combusted at any time in the reheat furnace.

Reheat furnace means a furnace used to heat steel product—including metal ingots, billets, slabs, beams, blooms and other similar products—for the purpose of deformation and rolling.

(b) Applicability. The requirements of this section apply to each new or existing reheat furnace at an iron and steel mill or ferroalloy manufacturing facility that directly emits or has the potential to emit 100 tons per year or more of NOX on or after August 4, 2023, does not have low-NOX burners installed, and is located within any of the States listed in § 52.40(c)(2), including Indian country located within the borders of any such State(s). Any existing reheat furnace with a potential to emit of 100 tons per year or more of NOX on August 4, 2023, will continue to be subject to the requirements of this section even if that unit later becomes subject to a physical or operational limitation that lowers its potential to emit below 100 tons per year of NOX.

(c) Emissions control requirements. If you are the owner or operator of an affected unit without low-NOX burners already installed, you must install and operate low-NOX burners or equivalent alternative low-NOX technology designed to achieve at least a 40% reduction from baseline NOX emissions in accordance with the work plan established pursuant to paragraph (d) of this section. You must meet the emissions limit established under paragraph (d) on a 30-day rolling average basis.

(d) Work plan requirements. (1) The owner or operator of each affected unit must submit a work plan for each affected unit by August 5, 2024. The work plan must be submitted via CEDRI or analogous electronic reporting approach provided by the EPA to report data required by this section following the procedures specified in § 52.40(g). Each work plan must include a description of the affected unit and rated production and energy capacities, identification of the low-NOX burner or alternative low NOX technology selected, and the phased construction timeframe by which you will design, install, and consistently operate the device. Each work plan shall also include, where applicable, performance test results obtained no more than five years before August 4, 2023, to be used as baseline emissions testing data providing the basis for required emissions reductions. If no such data exist, then the owner or operator must perform pre-installation testing as described in paragraph (e)(3) of this section.

(2) The owner or operator of an affected unit shall design each low-NOX burner or alternative low-NOX technology identified in the work plan to achieve NOX emission reductions by a minimum of 40% from baseline emission levels measured during performance testing that meets the criteria set forth in paragraph (e)(1) of this section, or during pre-installation testing as described in paragraph (e)(3) of this section. Each low-NOX burner or alternative low-NOX technology shall be continuously operated during all production periods according to paragraph (c) of this section.

(3) The owner or operator of an affected unit shall establish an emissions limit in the work plan that the affected unit must comply with in accordance with paragraph (c) of this section.

(4) The EPA's action on work plans:

(i) The Administrator will provide via the CEDRI or analogous electronic submission system provided by the EPA notification to the owner or operator of an affected unit if the submitted work plan is complete, that is, whether the request contains sufficient information to make a determination, within 60 calendar days after receipt of the original work plan and within 60 calendar days after receipt of any supplementary information.

(ii) The Administrator will provide notification via the CEDRI or analogous electronic submission system provided by the EPA, which shall be publicly available, to the owner or operator of a decision to approve or intention to disapprove the work plan within 60 calendar days after providing written notification pursuant to paragraph (d)(4)(i) of this section that the submitted work plan is complete.

(iii) Before disapproving a work plan, the Administrator will notify the owner or operator via the CEDRI or analogous electronic submission system provided by the EPA of the Administrator's intention to issue the disapproval, together with:

(A) Notice of the information and findings on which the intended disapproval is based; and

(B) Notice of opportunity for the owner or operator to present in writing, within 15 calendar days after he/she is notified of the intended disapproval, additional information or arguments to the Administrator before further action on the work plan.

(iv) The Administrator's final decision to disapprove a work plan will be via the CEDRI or analogous electronic submission system provided by the EPA and publicly available, and will set forth the specific grounds on which the disapproval is based. The final decision will be made within 60 calendar days after presentation of additional information or argument (if the submitted work plan is complete), or within 60 calendar days after the deadline for the submission of additional information or argument under paragraph (d)(5)(iii)(B) of this section, if no such submission is made.

(v) If the Administrator disapproves the submitted work plan for failure to satisfy the requirements of paragraphs (c) and (d)(1) through (3) of this section, or if the owner or operator of an affected unit fails to submit a work plan by August 5, 2024, the owner or operator will be in violation of this section. Each day that the affected unit operates following such disapproval or failure to submit shall constitute a violation.

(e) Testing and monitoring requirements. (1) If you are the owner or operator of an affected unit you must conduct performance tests, on an annual basis, in accordance with the applicable reference test methods of 40 CFR part 60, appendix A-4, any alternative test method approved by the EPA as of June 5, 2023, under 40 CFR 59.104(f), 60.8(b)(3), 61.13(h)(1)(ii), 63.7(e)(2)(ii), or 65.158(a)(2) and available at the EPA's website (https://www.epa.gov/emc/broadly-applicable-approved-alternative-test-methods), or other methods and procedures approved by the EPA through notice-and-comment rulemaking. The annual performance test does not have to be performed during the ozone season.

(2) If you are the owner or operator of an affected unit and are operating a NOX continuous emissions monitoring system (CEMS) that monitors NOX emissions from the affected unit, you may use the CEMS data in lieu of the annual performance tests and parametric monitoring required under this section. You must meet the following requirements for using CEMS to monitor NOX emissions:

(i) You shall install, calibrate, maintain, and operate a continuous emissions monitoring system (CEMS) for measuring NOX emissions and either oxygen (O2) or carbon dioxide (CO2).

(ii) The CEMS shall be operated and data recorded during all periods of operation during the ozone season of the affected unit except for CEMS breakdowns and repairs. Data shall be recorded during calibration checks and zero and span adjustments.

(iii) The 1-hour average NOX emissions rates measured by the CEMS shall be expressed in form of the emissions limit established in the work plan and shall be used to calculate the average emissions rates to demonstrate compliance with the applicable emissions limits established in the work plan.

(iv) The procedures under 40 CFR 60.13 shall be followed for installation, evaluation, and operation of the continuous monitoring systems.

(v) When NOX emissions data are not obtained because of CEMS breakdowns, repairs, calibration checks and zero and span adjustments, emissions data will be obtained by using standby monitoring systems, Method 7 of 40 CFR part 60, appendix A-4, Method 7A of 40 CFR part 60, appendix A-4, or other approved reference methods to provide emissions data for a minimum of 75 percent of the operating hours in each affected unit operating day, in at least 22 out of 30 successive operating days.

(3) If you are the owner or operator of an affected unit not operating NOX CEMS, you must conduct an initial performance test before the 2026 ozone season to establish appropriate indicator ranges for operating parameters and continuously monitor those operator parameters consistent with the requirements of paragraphs (e)(3)(i) through (iv) of this section.

(i) You must monitor and record stack exhaust gas flow rate and temperature during the initial performance test and subsequent annual performance tests to demonstrate continuous compliance with your NOX emissions limits.

(ii) You must use the stack exhaust gas flow rate and temperature during the initial performance test and subsequent annual performance tests to establish a site-specific indicator for these operating parameters.

(iii) You must repeat the performance test annually to reassess and adjust the site-specific operating parameter indicator ranges in accordance with the results of the performance test.

(iv) You must report and include your ongoing site-specific operating parameter data in the annual reports required under paragraph (f) of this section and semi-annual title V monitoring reports to the relevant permitting authority.

(f) Recordkeeping requirements. If you are the owner or operator of an affected unit, you shall maintain records of the following information for each day the affected unit operates:

(1) Calendar date;

(2) The average hourly NOX emissions rates measured or predicted;

(3) The 30-day average NOX emissions rates calculated at the end of each affected unit operating day from the measured or predicted hourly NOX emissions rates for the preceding 30 operating days;

(4) Identification of the affected unit operating days when the calculated 30-day average NOX emissions rates are in excess of the applicable site-specific NOX emissions limit with the reasons for such excess emissions as well as a description of corrective actions taken;

(5) Identification of the affected unit operating days for which pollutant data have not been obtained, including reasons for not obtaining sufficient data and a description of corrective actions taken;

(6) Identification of the times when emissions data have been excluded from the calculation of average emissions rates and the reasons for excluding data;

(7) If a CEMS is used to verify compliance:

(i) Identification of the times when the pollutant concentration exceeded full span of the CEMS;

(ii) Description of any modifications to the CEMS that could affect the ability of the CEMS to comply with Performance Specification 2 or 3 in appendix B to 40 CFR part 60; and

(iii) Results of daily CEMS drift tests and quarterly accuracy assessments as required under Procedure 1 of 40 CFR part 60, appendix F;

(8) Operating parameters required under paragraph (d) of this section to demonstrate compliance during the ozone season; and

(9) Each fuel type, usage, and heat content.

(g) Reporting requirements. (1) If you are the owner or operator of an affected unit, you shall submit a final report via the CEDRI or analogous electronic submission system provided by the EPA, by no later than March 30, 2026, certifying that installation of each selected control device has been completed. You shall include in the report the dates of final construction and relevant performance testing, where applicable, demonstrating compliance with the selected emission limits pursuant to paragraphs (c) and (d) of this section.

(2) If you are the owner or operator of an affected unit, you must submit the results of the performance test or performance evaluation of the CEMS following the procedures specified in § 52.40(g) within 60 days after the date of completing each performance test required by this section.

(3) If you are the owner or operator of an affected unit, you are required to submit excess emissions reports for any excess emissions that occurred during the reporting period. Excess emissions are defined as any calculated 30-day rolling average NOX emissions rate that exceeds the applicable emissions limit established under paragraphs (c) and (d) of this section. Excess emissions reports must be submitted in PDF format to the EPA via CEDRI or analogous electronic reporting approach provided by the EPA to report data required by this section following the procedures specified in § 52.40(g).

(4) If you are the owner or operator of an affected unit, you shall submit an annual report in PDF format to the EPA by January 30th of each year via CEDRI or analogous electronic reporting approach provided by the EPA to report data required by this section. Annual reports shall be submitted following the procedures in § 52.40(g). The report shall include records all records required by paragraphs (e) and (f) of this section, including record of CEMS data or operating parameters required by paragraph (e) to demonstrate compliance the applicable emissions limits established under paragraphs (c) and (d) of this section.

(h) Initial notification requirements for existing affected units. (1) The requirements of this paragraph (h) apply to the owner or operator of an existing affected unit.

(2) The owner or operator of an existing affected unit that emits or has a potential to emit 100 tons per year or more of NOX as of August 4, 2023, shall notify the Administrator via the CEDRI or analogous electronic submission system provided by the EPA that the unit is subject to this section. The notification, which shall be submitted not later than December 4, 2023, shall be submitted in PDF format to the EPA via CEDRI, which can be accessed through the EPA's CDX (https://cdx.epa.gov/). The notification shall provide the following information:

(i) The name and address of the owner or operator;

(ii) The address (i.e., physical location) of the affected unit;

(iii) An identification of the relevant standard, or other requirement, that is the basis for the notification and the unit's compliance date; and

(iv) A brief description of the nature, size, design, and method of operation of the facility and an identification of the types of emissions points (units) within the facility subject to the relevant standard.

[88 FR 36869, June 5, 2023]