Facility – means the combination of all structures, buildings, equipment, storage tanks, source operations, and other operations located on one or more contiguous or adjacent properties owned or operated by the same person.

Federally enforceable – means all limitations and conditions on operation, productions, or emissions that can be enforced by the USEPA pursuant to authorities that include, but are not limited to, those established in rule, regulation, or permit.

Federal Implementation Plan (FIP) – Under current law, a federally implemented plan to achieve attainment of air quality standards, used when a state is unable to develop an adequate plan.

FRM – means Federal Reference Method.

Fossil Fuel - Fuel derived from ancient organic remains; e.g. peat, coal, crude oil, and natural gas.

Fuel – means solid, liquid or gaseous material used to produce useful heat by burning.

Fugitive Emissions – Emissions not caught by a capture system.