Source
Source means any governmental, institutional, commercial, or industrial structure, installation, plant, building, or facility that emits or has the potential to emit any regulated air pollutant under the Clean Air Act. For purposes of section 502 of the Clean Air Act, a source, including a source with multiple units, shall be considered a single facility.
Source
40 CFR § 97.2
Scoping language
The terms used in this part shall have the meanings set forth in this section as follows: