(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 units means a glass manufacturing furnace meeting the applicability criteria of this section.

Borosilicate recipe means glass product composition of the following approximate ranges of weight proportions: 60 to 80 percent silicon dioxide, 4 to 10 percent total R2O (e.g., Na2O and K2O), 5 to 35 percent boric oxides, and 0 to 13 percent other oxides.

Container glass means glass made of soda-lime recipe, clear or colored, which is pressed and/or blown into bottles, jars, ampoules, and other products listed in Standard Industrial Classification (SIC) 3221 (SIC 3221).

Flat glass means glass made of soda-lime recipe and produced into continuous flat sheets and other products listed in SIC 3211.

Glass melting furnace means a unit comprising a refractory vessel in which raw materials are charged, melted at high temperature, refined, and conditioned to produce molten glass. The unit includes foundations, superstructure and retaining walls, raw material charger systems, heat exchangers, melter cooling system, exhaust system, refractory brick work, fuel supply and electrical boosting equipment, integral control systems and instrumentation, and appendages for conditioning and distributing molten glass to forming apparatuses. The forming apparatuses, including the float bath used in flat glass manufacturing and flow channels in wool fiberglass and textile fiberglass manufacturing, are not considered part of the glass melting furnace.

Glass produced means the weight of the glass pulled from the glass melting furnace.

Idling means the operation of a glass melting furnace at less than 25% of the permitted production capacity or fuel use capacity as stated in the operating permit.

Lead recipe means glass product composition of the following ranges of weight proportions: 50 to 60 percent silicon dioxide, 18 to 35 percent lead oxides, 5 to 20 percent total R2O (e.g., Na2O and K2O), 0 to 8 percent total R2O3 (e.g., Al2O3), 0 to 15 percent total RO (e.g., CaO, MgO), other than lead oxide, and 5 to 10 percent other oxides.

Operating day means a 24-hr period beginning at 12:00 midnight during which the furnace combusts fuel at any time but excludes any period of startup, shutdown, or idling during which the affected unit complies with the requirements in paragraphs (d) through (f) of this section, as applicable.

Pressed and blown glass means glass which is pressed, blown, or both, including textile fiberglass, noncontinuous flat glass, noncontainer glass, and other products listed in SIC 3229. It is separated into: Glass of borosilicate recipe, Glass of soda-lime and lead recipes, and Glass of opal, fluoride, and other recipes.

Raw material means minerals, such as silica sand, limestone, and dolomite; inorganic chemical compounds, such as soda ash (sodium carbonate), salt cake (sodium sulfate), and potash (potassium carbonate); metal oxides and other metal-based compounds, such as lead oxide, chromium oxide, and sodium antimonate; metal ores, such as chromite and pyrolusite; and other substances that are intentionally added to a glass manufacturing batch and melted in a glass melting furnace to produce glass. Metals that are naturally-occurring trace constituents or contaminants of other substances are not considered to be raw materials.

Shutdown means the period of time during which a glass melting furnace is taken from an operational to a non-operational status by allowing it to cool down from its operating temperature to a cold or ambient temperature as the fuel supply is turned off.

Soda-lime recipe means glass product composition of the following ranges of weight proportions: 60 to 75 percent silicon dioxide, 10 to 17 percent total R2O (e.g., Na2O and K2O), 8 to 20 percent total RO but not to include any PbO (e.g., CaO, and MgO), 0 to 8 percent total R2O3 (e.g., Al2O3), and 1 to 5 percent other oxides.

Startup means the period of time, after initial construction or a furnace rebuild, during which a glass melting furnace is heated to operating temperatures by the primary furnace combustion system, and systems and instrumentation are brought to stabilization.

Textile fiberglass means fibrous glass in the form of continuous strands having uniform thickness.

Wool fiberglass means fibrous glass of random texture, including accoustical board and tile (mineral wool), fiberglass insulation, glass wool, insulation (rock wool, fiberglass, slag, and silicia minerals), and mineral wool roofing mats.

(b) Applicability. You are subject to the requirements under this section if you own or operate a new or existing glass manufacturing furnace that directly emits or has the potential to emit 100 tons per year or more of NOX on or after August 4, 2023, 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 glass manufacturing 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 limitations. If you are the owner or operator of an affected unit, you must meet the emissions limitations in paragraphs (c)(1) and (2) of this section on a 30-day rolling average basis during the 2026 ozone season and in each ozone season thereafter. For the 2026 ozone season, the emissions limitations in paragraphs (c)(1) and (2) do not apply during shutdown and idling if the affected unit complies with the requirements in paragraphs (e) and (f) of this section, as applicable. For the 2027 and subsequent ozone seasons, the emissions limitations in paragraphs (c)(1) and (2) do not apply during startup, shutdown, and idling, if the affected unit complies with the requirements in paragraphs (d) through (f) of this section, as applicable.

(1) Container glass, pressed/blown glass, or fiberglass manufacturing furnace: 4.0 lb/ton of glass; and

(2) Flat glass manufacturing furnace: 7.0 lb/ton of glass.

(d) Startup requirements. (1) If you are the owner or operator of an affected unit, you shall submit via the CEDRI or analogous electronic submission system provided by the EPA, no later than 30 days prior to the anticipated date of startup, the following information to assure proper operation of the furnace:

(i) A detailed list of activities to be performed during startup and explanations to support the length of time needed to complete each activity.

(ii) A description of the material process flow rates, system operating parameters, and other information that the owner or operator shall monitor and record during the startup period.

(iii) Identification of the control technologies or strategies to be utilized.

(iv) A description of the physical conditions present during startup periods that prevent the controls from being effective.

(v) A reasonably precise estimate as to when physical conditions will have reached a state that allows for the effective control of emissions.

(2) The length of startup following activation of the primary furnace combustion system may not exceed:

(i) Seventy days for a container, pressed or blown glass furnace;

(ii) Forty days for a fiberglass furnace; and

(iii) One hundred and four days for a flat glass furnace and for all other glass melting furnaces not covered under paragraphs (d)(2)(i) and (ii) of this section.

(3) During the startup period, the owner or operator of an affected unit shall maintain the stoichiometric ratio of the primary furnace combustion system so as not to exceed 5 percent excess oxygen, as calculated from the actual fuel and oxidant flow measurements for combustion in the affected unit.

(4) The owner or operator of an affected unit shall place the emissions control system in operation as soon as technologically feasible during startup to minimize emissions.

(e) Shutdown requirements. (1) If you are the owner or operator of an affected unit, you shall submit via the CEDRI or analogous electronic submission system provided by the EPA to the Administrator, no later than 30 days prior to the anticipated date of shutdown, the following information to assure proper operation of the furnace:

(i) A detailed list of activities to be performed during shutdown and explanations to support the length of time needed to complete each activity.

(ii) A description of the material process flow rates, system operating parameters, and other information that the owner or operator shall monitor and record during the shutdown period.

(iii) Identification of the control technologies or strategies to be utilized.

(iv) A description of the physical conditions present during shutdown periods that prevent the controls from being effective.

(v) A reasonably precise estimate as to when physical conditions will have reached a state that allows for the effective control of emissions.

(2) The duration of a shutdown, as measured from the time the furnace operations drop below 25% of the permitted production capacity or fuel use capacity to when all emissions from the furnace cease, may not exceed 20 days.

(3) If you are the owner or operator of an affected unit, you shall operate the emissions control system whenever technologically feasible during shutdown to minimize emissions.

(f) Idling requirements. (1) If you are the owner or operator of an affected unit, you shall operate the emissions control system whenever technologically feasible during idling to minimize emissions.

(2) If you are the owner or operator of an affected unit, your NOX emissions during idling may not exceed the amount calculated using the following equation: Pounds per day emissions limit of NOX = (Applicable NOX emissions limit specified in paragraph (c) of this section expressed in pounds per ton of glass produced) × (Furnace permitted production capacity in tons of glass produced per day).

(3) To demonstrate compliance with the alternative daily NOX emissions limit identified in paragraph (f)(2) of this section during periods of idling, the owners or operators of an affected unit shall maintain records consistent with paragraph (h)(3) of this section.

(g) Testing and monitoring requirements. (1) If you own or operate an affected unit subject to the NOX emissions limits under paragraph (c) of this section 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. Owners or operators of affected units must calculate and record the 30-day rolling average emissions rate of NOX as the total of all hourly emissions data for an affected unit in the preceding 30 days, divided by the total tons of glass produced in that affected unit during the same 30-day period. Direct measurement or material balance using good engineering practice shall be used to determine the amount of glass produced during the performance test. The rate of glass produced is defined as the weight of glass pulled from the affected unit during the performance test divided by the number of hours taken to perform the performance test.

(2) If you are the owner or operator of an affected unit subject to the NOX emissions limits under paragraph (c)(1) of this section and are operating a NOX 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 terms of lbs/ton of glass and shall be used to calculate the average emissions rates to demonstrate compliance with the applicable emissions limits in this section.

(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 (g)(3)(i) through (iv) of this section.

(i) You must monitor and record stack exhaust gas flow rate, hourly glass production, and stack exhaust gas 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, hourly glass production, and stack exhaust gas temperature during the initial performance test and subsequent annual performance tests as NOX CEMS indicators to demonstrate continuous compliance and establish a site-specific indicator ranges 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 (h) of this section and semi-annual title V monitoring reports to the relevant permitting authority.

(4) If you are the owner or operator of an affected unit seeking to comply with the requirements for startup under paragraph (d) of this section or shutdown under paragraph (e) of this section in lieu of the applicable emissions limit under paragraph (c) of this section, you must monitor material process flow rates, fuel throughput, oxidant flow rate, and the selected system operating parameters in accordance with paragraphs (d)(1)(ii) and (e)(1)(ii) of this section.

(h) Recordkeeping requirements. (1) 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:

(i) Calendar date;

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

(iii) 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;

(iv) 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;

(v) 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;

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

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

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

(B) 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

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

(D) Operating parameters required under paragraph (g) to demonstrate compliance during the ozone season;

(viii) Each fuel type, usage, and heat content; and

(ix) Glass production rate.

(2) If you are the owner or operator of an affected unit, you shall maintain all records necessary to demonstrate compliance with the startup and shutdown requirements in paragraphs (d) and (e) of this section, including but not limited to records of material process flow rates, system operating parameters, the duration of each startup and shutdown period, fuel throughput, oxidant flow rate, and any additional records necessary to determine whether the stoichiometric ratio of the primary furnace combustion system exceeded 5 percent excess oxygen during startup.

(3) If you are the owner or operator of an affected unit, you shall maintain records of daily NOX emissions in pounds per day for purposes of determining compliance with the applicable emissions limit for idling periods under paragraph (f)(2) of this section. Each owner or operator shall also record the duration of each idling period.

(i) Reporting requirements. (1) 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.

(2) 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 in paragraph (c) 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).

(3) If you own or operate 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 paragraph (g) of this section, including record of CEMS data or operating parameters to demonstrate continuous compliance the applicable emissions limits under paragraphs (c) of this section.

(j) Initial notification requirements for existing affected units. (1) The requirements of this paragraph (j) 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 greater than 100 tons per year or greater 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, as amended at 88 FR 49303, July 31, 2023]