California Public Resources Code Section 3765

The director, after hearing, shall affirm, set aside, or modify the order from which the appeal is taken. Within 10 days after hearing the evidence, the director shall make a written decision with respect to the order appealed from. The decision of the director shall forthwith be filed with the supervisor and upon such filing shall be final. In case the order is affirmed or modified, the director shall retain jurisdiction until such time as the work ordered to be done by the order is finally completed. The written decision shall be served upon the lessor, lessee, or any operator or any well owner, or the owner of any rig, derrick, or other operating structure, or his local agent, and shall supersede the previous order of the supervisor. In case no written decision is made by the director within 30 days after the date of notice of hearing as provided in Section 3764, the order of the supervisor shall be effective upon the supervisor`s notifying any such person that the director has failed to make a decision and subject only to review by writ of certiorari from the superior court as provided in this chapter.