Section 117.123 - Source Cap(a) An owner or operator may achieve compliance with the nitrogen oxides (NOX) emission specifications of § 117.105 of this title (relating to Emission Specifications for Reasonably Available Control Technology (RACT)) or § 117.110 of this title (relating to Emission Specifications for Attainment Demonstration), by achieving equivalent NOX emission reductions obtained by compliance with a source cap emission limitation in accordance with the requirements of this section. Each equipment category at a source whose individual emission units would otherwise be subject to the NOX emission specifications of § 117.105 or § 117.110 of this title may be included in the source cap. Any equipment category included in the source cap must include all emission units belonging to that category. Equipment categories include, but are not limited to, the following: steam generation, electrical generation, and units with the same product outputs, such as ethylene cracking furnaces. All emission units not included in the source cap must comply with the requirements of § 117.105 or § 117.110 of this title, or § 117.115 of this title (relating to Alternative Plant-Wide Emission Specifications).(b) The source cap allowable mass emission rate must be calculated as follows. (1) A rolling 30-day average emission cap must be calculated for all emission units included in the source cap using the following equation. Attached Graphic
(2) A maximum daily cap must be calculated for all emission units included in the source cap using the following equation. Attached Graphic
(3) Each emission unit included in the source cap is subject to the requirements of both paragraphs (1) and (2) of this subsection at all times.(4) The owner or operator at its option may include any of the entire classes of exempted units listed in § 117.115(f) of this title in a source cap. For compliance with §117.105(a) - (d) of this title, such units are required to reduce emissions available for use in the cap by an additional amount calculated in accordance with the United States Environmental Protection Agency's proposed Economic Incentive Program rules for offset ratios for trades between RACT and non-RACT sources, as published in the February 23, 1993, Federal Register (58 FR 11110).(5) For stationary internal combustion engines, the source cap allowable emission rate must be calculated in pounds per hour using the procedures specified in § 117.115(g)(2) of this title.(6) For stationary gas turbines, the source cap allowable emission rate must be calculated in pounds per hour using the procedures specified in § 117.115(g)(3) of this title.(c) The owner or operator who elects to comply with this section shall: (1) for each unit included in the source cap, either:(A) install, calibrate, maintain, and operate a continuous exhaust NOX monitor, carbon monoxide (CO) monitor, an oxygen (O2) (or carbon dioxide (CO 2)) diluent monitor, and a totalizing fuel flow meter in accordance with the requirements of § 117.140 of this title (relating to Continuous Demonstration of Compliance). The required continuous emissions monitoring systems (CEMS) and fuel flow meters must be used to measure NO X, CO, and O2 (or CO 2) emissions and fuel use for each affected unit and must be used to demonstrate continuous compliance with the source cap;(B) install, calibrate, maintain, and operate a predictive emissions monitoring system (PEMS) and a totalizing fuel flow meter in accordance with the requirements of § 117.140 of this title. The required PEMS and fuel flow meters must be used to measure NOX, CO, and O2 (or CO2) emissions and fuel flow for each affected unit and must be used to demonstrate continuous compliance with the source cap; or(C) for units not subject to continuous monitoring requirements and units belonging to the equipment classes listed in § 117.115(f) of this title, the owner or operator may use the maximum emission rate as measured by hourly emission rate testing conducted in accordance with § 117.135(e) of this title (relating to Initial Demonstration of Compliance) in lieu of CEMS or PEMS. Emission rates for these units are limited to the maximum emission rates obtained from testing conducted under § 117.135(e) of this title; and(2) for each operating unit equipped with CEMS, either use a PEMS in accordance with § 117.140 of this title, or the maximum emission rate as measured by hourly emission rate testing conducted in accordance with § 117.135(e) of this title, to provide emissions compliance data during periods when the CEMS is off-line. The methods specified in 40 Code of Federal Regulations §75.46 must be used to provide emissions substitution data for units equipped with PEMS.(d) The owner or operator of any units subject to a source cap shall maintain daily records indicating the NOX emissions from each source and the total fuel usage for each unit and include a total NOX emissions summation and total fuel usage for all units under the source cap on a daily basis. Records must also be retained in accordance with § 117.145 of this title (relating to Notification, Recordkeeping, and Reporting Requirements).(e) The owner or operator of any units operating under this provision shall report any exceedance of the source cap emission limit within 48 hours to the appropriate regional office. The owner or operator shall then follow up within 21 days of the exceedance with a written report that includes an analysis of the cause for the exceedance with appropriate data to demonstrate the amount of emissions in excess of the applicable limit and the necessary corrective actions taken by the company to assure future compliance. Additionally, the owner or operator shall submit semiannual reports for the monitoring systems in accordance with § 117.145 of this title.(f) The owner or operator shall demonstrate initial compliance with the source cap in accordance with the schedule specified in § 117.9000 of this title (relating to Compliance Schedule for Beaumont-Port Arthur Ozone Nonattainment Area Major Sources).(g) For compliance with §117.105(a) - (d) of this title by November 15, 1999, a unit that has operated since November 15, 1990, and has since been permanently retired or decommissioned and rendered inoperable prior to June 9, 1993, may be included in the source cap emission limit under the following conditions. (1) The unit must have actually operated since November 15, 1990.(2) For purposes of calculating the source cap emission limit, the applicable emission limit for retired units must be calculated in accordance with subsection (b) of this section.(3) The actual heat input must be calculated according to subsection (b)(1) of this section. If the unit was not in service 24 consecutive months between January 1, 1990, and June 9, 1993, the actual heat input must be the average daily heat input for the continuous time period that the unit was in service, plus one standard deviation of the average daily heat input for that period. The maximum heat input must be the maximum heat input, as certified to the executive director, allowed or possible (whichever is lower) in a 24-hour period.(4) The owner or operator shall certify the unit's operational level and maximum rated capacity.(5) Emission reductions from shutdowns or curtailments that have not been used for netting or offset purposes under the requirements of Chapter 116 of this title or have not resulted from any other state or federal requirement may be included in the baseline for establishing the cap.(h) For compliance with §117.105(e) or§ 117.110 of this title, a unit that has been permanently retired or decommissioned and rendered inoperable may be included in the source cap under the following conditions. (1) Shutdowns must have occurred after September 10, 1993.(2) The source cap emission limit for retired units is calculated in accordance with subsection (b) of this section.(3) The actual heat input must be calculated according to subsection (b)(1) of this section. If the unit was not in service 24 consecutive months between January 1, 1997, and December 31, 1999, the actual heat input must be the average daily heat input for the continuous time period that the unit was in service, consistent with the heat input used to represent the unit's emissions in the attainment demonstration modeling inventory. The maximum heat input must be the maximum heat input, as certified to the executive director, allowed or possible (whichever is lower) in a 24-hour period.(4) The owner or operator shall certify the unit's operational level and maximum rated capacity.(5) Emission reductions from shutdowns or curtailments that have been used for netting or offset purposes under the requirements of Chapter 116 of this title may not be included in the baseline for establishing the cap.(i) A unit that has been shut down and rendered inoperable after June 9, 1993, but not permanently retired, should be identified in the initial control plan and may be included in the source cap to comply with the NOX emission specifications of this division required by November 15, 1999.(j) An owner or operator who chooses to use the source cap option shall include in the initial control plan, if required to be filed under § 117.150 of this title (relating to Initial Control Plan Procedures), a plan for initial compliance. The owner or operator shall include in the initial control plan the identification of the election to use the source cap procedure as specified in this section to achieve compliance with this section and shall specifically identify all sources that will be included in the source cap. The owner or operator shall also include in the initial control plan the method of calculating the actual heat input for each unit included in the source cap, as specified in subsection (b)(1) of this section. An owner or operator who chooses to use the source cap option shall include in the final control plan procedures of § 117.152 of this title (relating to Final Control Plan Procedures for Reasonably Available Control Technology) the information necessary under this section to demonstrate initial compliance with the source cap.(k) For the purposes of determining compliance with the source cap emission limit, the contribution of each affected unit that is operating during a startup, shutdown, or emissions event, as defined in § 101.1 of this title (relating to Definitions), must be calculated from the NOX emission rate, as measured by the initial demonstration of compliance, for that unit, unless the owner or operator provides data demonstrating to the satisfaction of the executive director that actual emissions were less than maximum emissions during such periods.30 Tex. Admin. Code § 117.123
The provisions of this §117.123 adopted to be effective June 14, 2007, 32 TexReg 3206