ID number
Well identification (ID) number means the unique and permanent identification number assigned to a petroleum or natural gas well. If the well has been assigned a US Well Number, the well ID number required in this subpart is the US Well Number. If a US Well Number has not been assigned to the well, the well ID number is the identifier established by the well's permitting authority.
Source
40 CFR § 98.238
Scoping language
Except as provided in this section, all terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part.