California Code, Public Resources Code - PRC § 45012

(a) If an enforcement agency, despite having made a good faith effort pursuant to its enforcement authority or any other authority, is unable to correct a violation, and the board, acting through its executive director, and the enforcement agency both agree that enforcement by the board is feasible and desirable pursuant to these circumstances, the board, acting through its executive director, may take any appropriate enforcement action pursuant to this section.

(c) Notwithstanding subdivisions (a) and (b), if the board finds that an enforcement agency's failure to take enforcement action constitutes an imminent threat to public health and safety or to the environment, the board may take the enforcement action that the board determines is necessary.