(a) No person shall allow the discharge of air contaminants into the atmosphere to exceed the emission specifications of this section, except as provided in §§117.315, 117.323, or 117.9800 of this title (relating to Alternative Plant-Wide Emission Specifications; Source Cap; and Use of Emission Credits for Compliance).
  (1) For purposes of this subchapter, the lower of any permit nitrogen oxides (NOX ) emission limit in effect on June 9, 1993, under a permit issued in accordance with Chapter 116 of this title (relating to Control of Air Pollution by Permits for New Construction or Modification) and the emission specifications of subsections (b) - (d) of this section apply, except that:
    (A) gas-fired boilers and process heaters operating under a permit issued after March 3, 1982, with a NOX emission limit of 0.12 pounds per million British thermal units (lb/MMBtu) heat input, are limited to that rate for the purposes of this subchapter; and
    (B) gas-fired boilers and process heaters that have had NOX reduction projects permitted since November 15, 1990, and prior to June 9, 1993, that were solely for the purpose of making early NOX reductions, are subject to the appropriate emission specification of subsection (b) of this section. The affected person shall document that the NOX reduction project was solely for the purpose of obtaining early reductions, and include this documentation in the initial control plan required in §117.350 of this title (relating to Initial Control Plan Procedures).
  (2) For purposes of calculating NOX emission limitations under this section from existing permit limits, the following procedure must be used:
    (A) the NOX emission limit explicitly stated in lb/MMBtu of heat input by permit provision (converted from low heating value to high heating value, as necessary); or
    (B) the NOX emission limit is the limit calculated as the permit Maximum Allowable Emission Rate Table emission limit in pounds per hour, divided by the maximum heat input to the unit in million British thermal units per hour (MMBtu/hr), as represented in the permit application. In the event the maximum heat input to the unit is not explicitly stated in the permit application, the rate must be calculated from Table 6 of the permit application, using the design maximum fuel flow rate and higher heating value of the fuel, or, if neither of the above are available, the unit's nameplate heat input.
  (3) For any unit placed into service after June 9, 1993, and before the final compliance date as specified in §117.9020 of this title (relating to Compliance Schedule for Houston-Galveston-Brazoria Ozone Nonattainment Area Major Sources) as functionally identical replacement for an existing unit or group of units subject to the provisions of this chapter, the higher of any permit NOX emission limit under a permit issued after June 9, 1993, in accordance with Chapter 116 of this title and the emission limits of subsections (b) - (d) of this section applies. Any emission credits resulting from the operation of such replacement units are limited to the cumulative maximum rated capacity of the units replaced. The inclusion of such new units is an optional method for complying with the emission limitations of §117.315 or §117.323 of this title. Compliance with this paragraph does not eliminate the requirement for new units to comply with Chapter 116 of this title.
(b) For each boiler and process heater with a maximum rated capacity greater than or equal to 100.0 MMBtu/hr of heat input, the applicable NOX emission specification is as follows:
  (1) gas-fired boilers, as follows:
    (A) low heat release boilers with no preheated air or preheated air less than 200 degrees Fahrenheit, 0.10 lb/MMBtu of heat input;
    (B) low heat release boilers with preheated air greater than or equal to 200 degrees Fahrenheit and less than 400 degrees Fahrenheit, 0.15 lb/MMBtu of heat input;
    (C) low heat release boilers with preheated air greater than or equal to 400 degrees Fahrenheit, 0.20 lb/MMBtu of heat input;
    (D) high heat release boilers with no preheated air or preheated air less than 250 degrees Fahrenheit, 0.20 lb/MMBtu of heat input;
    (E) high heat release boilers with preheated air greater than or equal to 250 degrees Fahrenheit and less than 500 degrees Fahrenheit, 0.24 lb/MMBtu of heat input; or
    (F) high heat release boilers with preheated air greater than or equal to 500 degrees Fahrenheit, 0.28 lb/MMBtu of heat input;
  (2) gas-fired process heaters, based on either air preheat temperature or firebox temperature, as follows:
    (A) based on air preheat temperature:
      (i) process heaters with preheated air less than 200 degrees Fahrenheit, 0.10 lb/MMBtu of heat input;
      (ii) process heaters with preheated air greater than or equal to 200 degrees Fahrenheit and less than 400 degrees Fahrenheit, 0.13 lb/MMBtu of heat input; or
      (iii) process heaters with preheated air greater than or equal to 400 degrees Fahrenheit, 0.18 lb/MMBtu of heat input; or
    (B) based on firebox temperature:
      (i) process heaters with a firebox temperature less than 1,400 degrees Fahrenheit, 0.10 lb/MMBtu of heat input;
      (ii) process heaters with a firebox temperature greater than or equal to 1,400 degrees Fahrenheit and less than 1,800 degrees Fahrenheit, 0.125 lb/MMBtu of heat input; or
      (iii) process heaters with a firebox temperature greater than or equal to 1,800 degrees Fahrenheit, 0.15 lb/MMBtu of heat input;
  (3) liquid fuel-fired boilers and process heaters, 0.30 lb/MMBtu of heat input;
  (4) wood fuel-fired boilers and process heaters, 0.30 lb/MMBtu of heat input;
  (5) any unit operated with a combination of gaseous, liquid, or wood fuel, a variable emission limit calculated as the heat input weighted sum of the applicable emission limits of this subsection;
  (6) for any gas-fired boiler or process heater firing gaseous fuel that contains more than 50% hydrogen by volume, over an eight-hour period, in which the fuel gas composition is sampled and analyzed every three hours, a multiplier of up to 1.25 times the appropriate emission limit in this subsection may be used for that eight-hour period. The total hydrogen volume in all gaseous fuel streams will be divided by the total gaseous fuel flow volume to determine the volume percent of hydrogen in the fuel supply. The multiplier may not be used to increase limits set by permit. The following equation must be used by an owner or operator using a gas-fired boiler or process heater that is subject to this paragraph and one of the rolling 30-day averaging period emission limitations contained in paragraph (1) or (2) of this subsection to calculate an emission limitation for each rolling 30-day period:
Attached Graphic
  (7) for units that operate with a NO X continuous emissions monitoring system (CEMS) or predictive emissions monitoring system (PEMS) under §117.340 of this title (relating to Continuous Demonstration of Compliance), the emission specifications apply as:
    (A) the mass of NOX emitted per unit of energy input (lb/MMBtu), on a rolling 30-day average period; or
    (B) the mass of NOX emitted per hour (pounds per hour), on a block one-hour average, calculated as the product of the boiler's or process heater's maximum rated capacity and its applicable specification in lb/MMBtu; and
  (8) for units that do not operate with a NO X CEMS or PEMS under §117.340 of this title, the emission specifications apply in pounds per hour, as specified in paragraph (7)(B) of this subsection.
(c) No person shall allow the discharge into the atmosphere from any stationary gas turbine with a megawatt (MW) rating greater than or equal to 10.0 MW, emissions in excess of a block one-hour average concentration of 42 parts per million by volume (ppmv) NOX and 132 ppmv carbon monoxide (CO) at 15% oxygen (O2), dry basis. For stationary gas turbines equipped with CEMS or PEMS for CO, the owner or operator may elect to comply with the CO emission specification of this subsection using a 24-hour rolling average.
(d) No person shall allow the discharge into the atmosphere from any gas-fired, rich-burn, stationary, reciprocating internal combustion engine rated 150 horsepower (hp) or greater, NOX emissions in excess of a block one-hour average of 2.0 grams per horsepower-hour (g/hp-hr) and CO emissions is excess of a block one-hour average of 3.0 g/hp-hr.
(e) No person shall allow the discharge into the atmosphere from any boiler or process heater subject to NOX emission specifications in subsection (a) or (b) of this section, CO emissions in excess of the following limitations:
  (1) for gas or liquid fuel-fired boilers or process heaters, 400 ppmv at 3.0% O2, dry basis;
Cont'd...