California Code, Public Resources Code - PRC § 25530

The commission may order a reconsideration of all or part of a decision or order on its own motion or on petition of any party.

Any such petition shall be filed within 30 days after adoption by the commission of a decision or order. The commission shall not order a reconsideration on its own motion more than 30 days after it has adopted a decision or order. The commission shall order or deny reconsideration on a petition therefor within 30 days after the petition is filed.

A decision or order may be reconsidered by the commission on the basis of all pertinent portions of the record together with such argument as the commission may permit, or the commission may hold a further hearing, after notice to all interested persons. A decision or order of the commission on reconsideration shall have the same force and effect as an original order or decision.