"Multiple-chamber incinerator" means any article, machine, equipment contrivance, structure or part of a structure used to dispose of combustible refuse by burning, which consists of three or more refractory lined combustion furnaces in series, physically separated by refractory walls and interconnected by gas passage ports or ducts and employing adequate design parameters necessary for maximum combustion of the material to be burned.
Nev. Admin. Code § 445B.106
NRS 445B.210