|(a) Nitrogen oxides (NOX ) emission specifications. No person shall allow the discharge into the atmosphere from any gas-fired boiler or process heater with a maximum rated capacity equal to or greater than 40 million British thermal units per hour in the Beaumont-Port Arthur ozone nonattainment area, emissions of NOX in excess of the following, except as provided in subsection (d) of this section and §117.103(c) of this title (relating to Exemptions): (1) boilers, 0.10 pounds per million British thermal units (lb/MMBtu) of heat input; and (2) process heaters, 0.08 lb/MMBtu of heat input. (b) NOX averaging time. The emission specifications of subsection (a) of this section apply: (1) if the unit is operated with a NO X continuous emissions monitoring system (CEMS) or predictive emissions monitoring system (PEMS) under §117.140 of this title (relating to Continuous Demonstration of Compliance), either as: (A) a rolling 30-day average period, in the units of the applicable standard; (B) a block one-hour average, in the units of the applicable standard, or alternatively; (C) a block one-hour average, in pounds per hour, for boilers and process heaters, calculated as the product of the boiler's or process heater's maximum rated capacity and its applicable NO X emission specification in lb/MMBtu; and (2) if the unit is not operated with a NO X CEMS or PEMS under §117.140 of this title, a block one-hour average, in the units of the applicable standard. Alternatively for boilers and process heaters, the emission specifications may be applied in pounds per hour, as specified in paragraph (1)(C) of this subsection. (c) Related emissions. No person shall allow the discharge into the atmosphere from any unit subject to NOX emission specifications in subsection (a) of this section, emissions in excess of the following, except as provided in §117.125 of this title (relating to Alternative Case Specific Specifications) or paragraph (3) or (4) of this subsection. (1) Carbon monoxide (CO) emissions must not exceed 400 parts per million by volume (ppmv) at 3.0% oxygen (O2 ), dry basis (or alternatively, 3.0 grams per horsepower-hour for stationary internal combustion engines; or 775 ppmv at 7.0% O2 , dry basis for wood fuel-fired boilers or process heaters): (A) on a rolling 24-hour averaging period, for units equipped with CEMS or PEMS for CO; and (B) on a one-hour average, for units not equipped with CEMS or PEMS for CO. (2) For units that inject urea or ammonia into the exhaust stream for NOX control, ammonia emissions must not exceed 10 ppmv at 3.0% O2 , dry, for boilers and process heaters; 15% O2 , dry, for stationary gas turbines and gas-fired lean-burn engines; 0.0% O 2 , dry, for fluid catalytic cracking units (including CO boilers, CO furnaces, and catalyst regenerator vents); 7.0% O2 , dry, for boilers and industrial furnaces units that were regulated as existing facilities in 40 Code of Federal Regulations Part 266, Subpart H (as was in effect on June 9, 1993) and for wood-fired boilers; and 3.0% O 2 , dry, for all other units, based on: (A) a block one-hour averaging period for units not equipped with a CEMS or PEMS for ammonia; or (B) a rolling 24-hour averaging period for units equipped with CEMS or PEMS for ammonia. (3) The correction of CO emissions to 3.0% O 2 , dry basis, in paragraph (1) of this subsection does not apply to boilers and process heaters operating at less than 10% of maximum load and with stack O2 in excess of 15% (i.e., hot-standby mode). (4) The CO specifications in paragraph (1) of this subsection do not apply to stationary internal combustion engines subject to §117.105(e) of this title (relating to Emission Specifications for Reasonably Available Control Technology (RACT)). (d) Compliance flexibility. (1) An owner or operator may use any of the following alternative methods to comply with the NOX emission specifications of this section: (A) §117.115 of this title (relating to Alternative Plant-Wide Emission Specifications); (B) §117.123 of this title (relating to Source Cap); or (C) §117.9800 of this title (relating to Use of Emission Credits for Compliance). (2) Section 117.125 of this title is not an applicable method of compliance with the NOX emission specifications of this section. (3) An owner or operator may petition the executive director for an alternative to the CO or ammonia specifications of this section in accordance with §117.125 of this title.