“Natural gas” means a naturally occurring mixture of hydrocarbon and nonhydrocarbon gases found in geologic formations beneath the earth's surface, of which the principal constituent is methane.

Source. (See Revision Note at chapter heading for Env-A 1300) #9803, eff 10-31-10; ss by #12584, eff 8-15-18 (formerly Env-A 1302.32)