Facility or activity
Facility or activity means any HWM facility, UIC injection well, NPDES point source or treatment works treating domestic sewage or State 404 dredge or fill activity, or any other facility or activity (including land or appurtenances thereto) that is subject to regulation under the RCRA, UIC, NPDES, or 404 programs.
40 CFR § 124.2
In addition to the definitions given in 122.2 and 123.2 (NPDES), 501.2 (sludge management), 144.3 and 145.2 (UIC), 233.3 (404), and 270.2 and 271.2 (RCRA), the definitions below apply to this part, except for PSD permits which are governed by the definitions in 124.41. Terms not defined in this section have the meaning given by the appropriate Act.