California Code, Public Resources Code - PRC § 3251.5

(a) Notwithstanding Section 3251, a well shall be deemed a hazardous well if it has been determined by the supervisor to pose a present danger to life, health, or natural resources and has been abandoned in accordance with the requirements of the division in effect at the time of the abandonment 15 or more years before the date of the supervisor's determination that it poses such a danger.

(b) Reabandonment initiated by the supervisor shall not be affected by the timeline established in this section.