(a) The owner or operator of any source subject to this division (relating to Dallas-Fort Worth Eight-Hour Ozone Nonattainment Area Minor Sources) shall not allow the discharge into the atmosphere emissions of nitrogen oxides (NOX ) in excess of the following emission specifications.
  (1) Emission specifications for stationary, gas-fired, reciprocating internal combustion engines are as follows:
    (A) rich-burn engines:
      (i) fired on landfill gas, 0.60 grams per horsepower-hour (g/hp-hr); and
      (ii) all other rich-burn engines, 0.50 g/hp-hr; and
    (B) lean-burn engines:
      (i) placed into service before June 1, 2007, that have not been modified, reconstructed, or relocated on or after June 1, 2007, 0.70 g/hp-hr; and
      (ii) placed into service, modified, reconstructed, or relocated on or after June 1, 2007:
        (I) fired on landfill gas or other biogas, 0.60 g/hp-hr; and
        (II) all other lean-burn engines, 0.50 g/hp-hr.
  (2) The emission specification for stationary, dual-fuel, reciprocating internal combustion engines is 5.83 g/hp-hr.
  (3) Emission specifications for stationary, diesel, reciprocating internal combustion engines are as follows:
    (A) placed into service before March 1, 2009, that have not been modified, reconstructed, or relocated on or after March 1, 2009, the lower of 11.0 g/hp-hr or the emission rate established by testing, monitoring, manufacturer's guarantee, or manufacturer's other data; and
    (B) for engines not subject to subparagraph (A) of this paragraph:
      (i) with a horsepower (hp) rating of 50 hp or greater, but less than 100 hp, that are installed, modified, reconstructed, or relocated on or after March 1, 2009, 3.3 g/hp-hr;
      (ii) with a horsepower rating of 100 hp or greater, but less than or equal to 750 hp, that are installed, modified, reconstructed, or relocated on or after March 1, 2009, 2.8 g/hp-hr; and
      (iii) with a horsepower rating of 750 hp or greater that are installed, modified, reconstructed, or relocated on or after March 1, 2009, 4.5 g/hp-hr.
  (4) As an alternative to the emission specifications in paragraphs (1) - (3) of this subsection for units with an annual capacity factor of 0.0383 or less, 0.060 pound per million British thermal units (lb/MMBtu) heat input. For units placed into service on or before December 31, 2000, the annual capacity factor as of December 31, 2000, must be used to determine eligibility for the alternative emission specification of this paragraph. For units placed into service after December 31, 2000, a 12-month rolling average must be used to determine the annual capacity factor.
  (5) For the purposes of this subsection, the terms "modification" and "reconstruction" have the meanings defined in §116.10 of this title (relating to General Definitions) and 40 Code of Federal Regulations §60.15 (December 16, 1975), respectively, and the term "relocated" means to newly install at an account, as defined in §101.1 of this title (relating to Definitions), a used engine from anywhere outside that account.
(b) The averaging time for the NOX emission specifications of subsection (a) of this section is as follows:
  (1) if the unit is operated with a NOX continuous emissions monitoring system (CEMS) or predictive emissions monitoring system (PEMS) under §117.2135(c) of this title (relating to Monitoring, Notification, and Testing Requirements), 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, calculated as the product of the boiler's maximum rated capacity and its applicable limit in lb/MMBtu; or
  (2) if the unit is not operated with a NOX CEMS or PEMS under §117.2135(c) of this title, a block one-hour average, in the units of the applicable standard.
(c) The maximum rated capacity used to determine the applicability of the emission specifications in subsection (a) of this section must be the greater of the following:
  (1) the maximum rated capacity as of December 31, 2000; or
  (2) the maximum rated capacity after December 31, 2000.
(d) A unit's classification is determined by the most specific classification applicable to the unit as of December 31, 2000. For example, a unit that is classified as a stationary gas-fired engine as of December 31, 2000, but subsequently is authorized to operate as a dual-fuel engine, must be classified as a stationary gas-fired engine for the purposes of this chapter.
(e) Changes after December 31, 2000, to a unit subject to an emission specification in subsection (a) of this section (ESAD unit) that result in increased NOX emissions from a unit not subject to an emission specification in subsection (a) of this section (non-ESAD unit), such as redirecting one or more fuel or waste streams containing chemical-bound nitrogen to an incinerator or a flare, is only allowed if:
  (1) the increase in NOX emissions at the non-ESAD unit is determined using a CEMS or PEMS that meets the requirements of §117.2135(c) of this title, or through stack testing that meets the requirements of §117.2135(f) of this title; and
  (2) emission credits equal to the increase in NOX emissions at the non-ESAD unit are obtained and used in accordance with §117.9800 of this title (relating to Use of Emission Credits for Compliance).
(f) A source that met the definition of major source on December 31, 2000, is always classified as a major source for purposes of this chapter. A source that did not meet the definition of major source (i.e., was a minor source, or did not yet exist) on December 31, 2000, but becomes a major source at any time after December 31, 2000, is from that time forward always classified as a major source for purposes of this chapter.
(g) The availability under subsection (a)(4) of this section of an emission specification for units with an annual capacity factor of 0.0383 or less is based on the unit's status on December 31, 2000. Reduced operation after December 31, 2000, cannot be used to qualify for a more lenient emission specification under subsection (a)(4) of this section than would otherwise apply to the unit.
(h) 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 §117.2125 of this title (relating to Alternative Case Specific Specifications):
  (1) carbon monoxide (CO), 400 ppmv at 3.0% oxygen (O2 ), dry basis (or alternatively, 3.0 g/hp-hr for stationary internal combustion engines):
    (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; and
  (2) for units that inject urea or ammonia into the exhaust stream for NOX control, ammonia emissions of 10 ppmv at 15% O2 , dry, for gas-fired lean-burn engines and diesel engines; and 3.0% O2 , 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.
(i) An owner or operator may use emission reduction credits as specified in §117.9800 of this title to comply with the NOX emission specifications of this section.

Source Note: The provisions of this §117.2110 adopted to be effective June 14, 2007, 32 TexReg 3206; amended to be effective May 15, 2011, 36 TexReg 2855; amended to be effective May 16, 2024, 49 TexReg 3347