1. (1) Applicability. The requirements of this rule apply to all natural gas-fired and fuel oil-fired combined-cycle electric generating units which commence operation on or after April 1, 2003. The requirements of this rule do not pre-empt the applicability of any other State or Federal regulations.

2. (2) Definitions. For the purposes of this rule, the following definitions apply:

   1. (a) "Combined-Cycle Electric Generating Unit" means a system comprised of one or more combustion turbines, heat recovery steam generators, and steam turbines configured to improve overall efficiency of electricity generation or steam production.
   2. (b) "Commence Operation" means to have begun to produce steam, gas, or other heated medium used to generate electricity for use or sale, including test generation.
   3. (c) "Fuel Oil" means any petroleum-based fuel (including diesel fuel) as defined by the American Society for Testing and Materials in ASTM D396-90a, "Standard Specification for Fuel Oils".
   4. (d) "Natural Gas" means a naturally fluid mixture of hydrocarbons (e.g., methane, ethane, or propane) produced in geological formations beneath the Earth's surface that maintains a gaseous state at standard atmospheric temperature and pressure under ordinary conditions. Natural gas contains 20.0 grains or less of total sulfur per 100 standard cubic feet. Additionally, natural gas must either be composed of at least 70 percent methane by volume or have a gross calorific value between 950 and 1100 Btu per standard cubic foot. Natural gas does not include the following gaseous fuels: landfill gas, digester gas, refinery gas, sour gas, blast furnace gas, coal-derived gas, producer gas, coke oven gas, or any gaseous fuel produced in a process which might result in highly variable sulfur content or heating value.

3. (3) Emission Limitations.

   1. (a) No person shall cause or permit the emissions of nitrogen oxides from combined-cycle electric generating units fired by natural gas in excess of 4.0 ppmvd at 15% O2.
   2. (b) No person shall cause or permit the emissions of nitrogen oxides from combined-cycle electric generating units fired by fuel oil in excess of 15.0 ppmvd at 15% O2.
4. (4) Compliance Method. Compliance with the nitrogen oxides emissions limitations in paragraph (3) of this rule shall be determined by EPA Reference Method 20 as found in 40 CFR 60, Appendix A [and incorporated by reference in rule 335-3-10-.03(1)].

Author: Ronald W. Gore

Statutory Authority: Code of Alabama 1975, §§22-22A-5, 22-22A-6, 22-22A-8, 22-28-10, 22-28-11, 22-28-14, 22-28-18, 22-28-20, 22-28-22.

History: New Rule: Filed March 2, 2001; effective April 6, 2001. Filed March 14, 2012: [Certified rule refiled after agency adoption of suggested amendment by the Joint Committee on Administrative Regulation Review that the repeal of the rule will take effect when the department certifies to the Legislative Reference Service the federal CAIR rules have been repealed; effective March 14, 2012.] Repealed: Filed February 24, 2015; effective February 24, 2015: [The above rule was repealed by their own terms upon certification of the Alabama Department of Environmental Management that the federal Clean Air Interstate Rules (CAIR) are no longer in effect. The repeal became effective February 24, 2015, upon the department’s certification.] New Rule: Filed February 24, 2015; effective February 24, 2015: [The above rule became effective by their own terms upon certification of the Alabama Department of Environmental Management that the federal Clean Air Interstate Rules (CAIR) are no longer in effect. The rule became effective February 24, 2015, upon the department’s certification.]