40 CFR § 98.470
Definition of the source category
June 9, 2020
(a) The injection of carbon dioxide (CO2) source category comprises any well or group of wells that inject a CO2 stream into the subsurface.
(b) If you report under subpart RR of this part for a well or group of wells, you are not required to report under this subpart for that well or group of wells.
(c) A facility that is subject to this part only because it is subject to subpart UU of this part is not required to report emissions under subpart C of this part or any other subpart listed in §98.2(a)(1) or (a)(2).