California Code, Health and Safety Code - HSC § 79005

(a) Notwithstanding paragraph (1) of subdivision (b) of Section 78075, any person may voluntarily enter into an enforceable agreement with the department pursuant to this section that allows removal or remedial actions to be conducted under the oversight of the department at sites with petroleum releases from sources other than underground storage tanks, as defined in Section 25299.24.

(b) If the department determines that there may be an adverse impact to water quality as a result of a petroleum release, the department shall notify the appropriate regional board prior to entering into the enforceable agreement pursuant to this section. The department may enter into an enforceable agreement pursuant to this section unless, within 60 days of the notification provided by the department, the regional board provides the department with a written notice that the regional board will assume oversight responsibility for the removal or remedial action.

(c) Agreements entered into pursuant to this section shall provide that the party will reimburse the department for all costs incurred, including, but not limited to, oversight costs pursuant to the enforceable agreement associated with the performance of the removal or remedial actions and Chapter 6.66 (commencing with Section 25269) of Division 20.