Cal. Public Resources Code § 3190

For purposes of this article, the following definitions apply: (a) “Federal agency” means the United States Environmental Protection Agency, including Region 9 of that agency. (b) (1) “Gravity-based energy storage well” means a well that meets all of the following: (A) The well is plugged with all perforations sealed, including by the use of permanent bridge plug. (B) The well is isolated from a hydrocarbon reservoir. (C) The well has mechanical integrity. (D) The well is not a conduit for fluid migration into a beneficial use aquifer. (E) The well is exclusively used to store or generate energy by raising or lowering a weight within the well casing. (2) A well that has been fully plugged and abandoned pursuant to Section 3208 is not eligible to be a gravity-based energy storage well. (3) A well listed as an orphan well pursuant to subparagraph (C) of paragraph (1) of subdivision (a) of Section 3206.3 or an idle-deserted well, as defined in Section 3251, is eligible to be converted for use as a gravity-based energy storage well if all applicable and necessary rights to do so have been obtained.