(1) It is the intent of the legislature for a general permit or permit by rule adopted by the department under this section to streamline the permitting process for a stationary natural gas engine used in a combined heat and power system. It is the further intent of the legislature that a general permit or permit by rule be adopted and implemented as the permitting mechanism for the new construction of a combined heat and power system.

(2) The definitions in this subsection apply throughout this section unless the context clearly requires otherwise.

(a) "Natural gas" includes: Naturally occurring mixtures of hydrocarbon gases and vapors consisting principally of methane, whether in gaseous or liquid form; and biogas derived from landfills, wastewater treatment facilities, anaerobic digesters, and other sources of organic decomposition that have been purified to meet standards for natural gas derived from fossil fuel sources.

(b) "Stationary natural gas engine" includes any stationary, natural gas internal combustion engine, whether it is an internal combustion reciprocating engine or a gas turbine. The term does not include a natural gas engine that powers a motor vehicle or other mobile source.

(3) This section applies only to a stationary natural gas engine used in a combined heat and power system.

(4) The department shall issue a general permit or permit by rule for new stationary natural gas engines used in a combined heat and power system that establishes emission limits for air contaminants released by the engines.

(5) In adopting a general permit or permit by rule under this section, the department may consider:

(a) The geographic location in which a stationary natural gas engine may be used, including the proximity to an area designated as a nonattainment area;

(b) The total annual operating hours of a stationary natural gas engine;

(c) The technology used by a stationary natural gas engine;

(d) Whether the stationary natural gas engine will be a major stationary source or part of a new or modified major stationary source as those terms are utilized in Title I of the federal clean air act; and

(e) Other relevant emission control or clean air policies of the state.

(6) In addition to emission limits required by federal and state laws, the department must provide for the emission limits for stationary natural gas engines subject to this section to be measured in terms of air contaminant emissions per United States environmental protection agency unit of energy output. The department shall consider both the primary and secondary functions when determining the engine's emissions per unit of energy output.

Finding—Intent—2015 3rd sp.s. c 19: See note following RCW 39.35.010.