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Title 40

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Displaying title 40, up to date as of 8/14/2026. Title 40 was last amended 8/14/2026.
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  1. Title 40 —Protection of Environment
  2. Chapter I —Environmental Protection Agency
  3. Subchapter C —Air Programs
  4. Part 60 —Standards of Performance for New Stationary Sources
  5. Subpart KKKKa —Standards of Performance for Stationary Combustion Turbines
  6. Other Requirements and Information
  7. Table 1 to Subpart KKKKa of Part 60
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eCFR Content

The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. It is not an official legal edition of the CFR.

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Table 1 to Subpart KKKKa of Part 60—Nitrogen Oxide Emission Standards for Stationary Combustion Turbines

Cross Reference
Link to an amendment published at 91 FR 43568, July 16, 2026.
Combustion turbine type Combustion turbine base load rated heat input
(HHV)		 Input-based NOX
emission standard 1 		Optional output-based NOX standard 2
New, firing natural gas with utilization rate >45 percent >850 MMBtu/h 5 ppm at 15 percent O2 or 7.9 ng/J (0.018 lb/MMBtu) 0.054 kg/MWh-gross (0.12 lb/MWh-gross) 0.055 kg/MWh-net (0.12 lb/MWh-net).
New, firing natural gas with utilization rate ≤45 percent and with design efficiency ≥38 percent >850 MMBtu/h 25 ppm at 15 percent O2 or 40 ng/J (0.092 lb/MMBtu) 0.38 kg/MWh-gross (0.83 lb/MWh-gross) 0.39 kg/MWh-net (0.85 lb/MWh-net).
New, firing natural gas with utilization rate ≤45 percent and with design efficiency <38 percent >850 MMBtu/h 9 ppm at 15 percent O2 or 14 ng/J (0.033 lb/MMBtu) 0.17 kg/MWh-gross (0.37 lb/MWh-gross) 0.17 kg/MWh-net (0.38 lb/MWh-net).
New, modified, or reconstructed, firing non-natural gas >850 MMBtu/h 42 ppm at 15 percent O2 or 70 ng/J (0.16 lb/MMBtu) 0.45 kg/MWh-gross (1.0 lb/MWh-gross) 0.46 kg/MWh-net (1.0 lb/MWh-net).
Modified or reconstructed, firing natural gas, at all utilization rates, with design efficiency ≥38 percent >850 MMBtu/h 25 ppm at 15 percent O2 or 40 ng/J (0.092 lb/MMBtu) 0.38 kg/MWh-gross (0.83 lb/MWh-gross) 0.39 kg/MWh-net (0.85 lb/MWh-net).
Modified or reconstructed, firing natural gas, at all utilization rates, with design efficiency <38 percent >850 MMBtu/h 15 ppm at 15 percent O2 or 24 ng/J (0.055 lb/MMBtu) 0.28 kg/MWh-gross (0.62 lb/MWh-gross) 0.29 kg/MWh-net (0.30 lb/MWh-net).
New, firing natural gas, at utilization rate >45 percent >50 MMBtu/h and ≤850 MMBtu/h 15 ppm at 15 percent O2 or 24 ng/J (0.055 lb/MMBtu) 0.20 kg/MWh-gross (0.43 lb/MWh-gross) 0.20 kg/MWh-net (0.44 lb/MWh-net).
New, firing natural gas, at utilization rate ≤45 percent >50 MMBtu/h and ≤850 MMBtu/h 25 ppm at 15 percent O2 or 40 ng/J (0.092 lb/MMBtu) 0.54 kg/MWh-gross (1.2 lb/MWh-gross) 0.56 kg/MWh-net (1.2 lb/MWh-net).
Modified or reconstructed, firing natural gas >20 MMBtu/h and ≤850 MMBtu/h 42 ppm at 15 percent O2 or 67 ng/J (0.15 lb/MMBtu) 0.91 kg/MWh-gross (2.0 lb/MWh-gross) 0.92 kg/MWh-net (2.0 lb/MWh-net).
New, firing non-natural gas >50 MMBtu/h and ≤850 MMBtu/h 74 ppm at 15 percent O2 or 120 ng/J (0.29 lb/MMBtu) 1.6 kg/MWh-gross (3.6 lb/MWh-gross) 1.6 kg/MWh-net (3.7 lb/MWh-net).
Modified or reconstructed, firing non-natural gas >20 MMBtu/h and ≤850 MMBtu/h 96 ppm at 15 percent O2 or 160 ng/J (0.37 lb/MMBtu) 2.1 kg/MWh-gross (4.7 lb/MWh-gross) 2.2 kg/MWh-net (4.8 lb/MWh-net).
New, firing natural gas ≤50 MMBtu/h 25 ppm at 15 percent O2 or 40 ng/J (0.092 lb/MMBtu) 0.64 kg/MWh-gross (1.4 lb/MWh-gross) 0.65 kg/MWh-net (1.4 lb/MWh-net).
New, firing non-natural gas ≤50 MMBtu/h 96 ppm at 15 percent O2 or 160 ng/J (0.37 lb/MMBtu) 2.4 kg/MWh-gross (5.3 lb/MWh-gross) 2.5 kg/MWh-net (5.4 lb/MWh-net).
Modified or reconstructed, all fuels ≤20 MMBtu/h 150 ppm at 15 percent O2 or 240 ng/J (0.55 lb/MMBtu) 3.9 kg/MWh-gross (8.7 lb/MWh-gross) 4.0 kg/MWh-net (8.9 lb/MWh-net).
New, firing natural gas, either offshore turbines, turbines bypassing the heat recovery unit, and/or temporary turbines >50 MMBtu/h 25 ppm at 15 percent O2 or 40 ng/J (0.092 lb/MMBtu) N/A.
Located north of the Arctic Circle (latitude 66.5 degrees north), operating at ambient temperatures less than 0 °F (−18 °C), modified or reconstructed offshore turbines, operated during periods of turbine tuning, byproduct-fired turbines, and/or operating at less than 70 percent of the base load rating ≤300 MMBtu/h 150 ppm at 15 percent O2 or 240 ng/J) 0.55 lb/MMBtu N/A.
Located north of the Arctic Circle (latitude 66.5 degrees north), operating at ambient temperatures less than 0 °F (−18 °C), modified or reconstructed offshore turbines, operated during periods of turbine tuning, byproduct-fired turbines, and/or operating at less than 70 percent of the base load rating >300 MMBtu/h 96 ppm at 15 percent O2 or 150 ng/J (0.35 lb/MMBtu) N/A.
Heat recovery units operating independent of the combustion turbine All sizes 54 ppm at 15 percent O2 or 86 ng/J) 0.20 lb/MMBtu N/A.
1 Input-based standards are determined on a 4-operating-hour rolling average basis.
2 Output-based standards are determined on a 30-operating-day average basis.
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