Cal. Public Resources Code § 3322.1

No order of the supervisor creating a unit and prescribing the plan of unitization applicable thereto shall become effective unless and until the plan of unitization has been signed, or in writing ratified or approved, by working interest owners who are entitled to 65 percent of the proceeds of production of oil and gas, prior to the payment of royalties, within the proposed unit area, measured by the production from such area in the calendar year preceding the date of the order of the supervisor creating such unit, and the supervisor has made a finding either in the order creating the unit or in a supplemental order that the plan of unitization has been so signed, ratified or approved by persons owning the required percentage interest in and to the unit area. Where the plan of unitization has not been so signed, ratified or approved by persons owning the required percentage interest in and to the unit area at the time the order creating the unit is made, the supervisor shall, upon petition and notice, hold such additional and supplemental hearings as may be requested or required to determine if and when the plan of unitization has been so signed, ratified or approved by persons owning the required percentage interest in and to such unit area and shall, in respect to such hearings, make and enter a finding of his determination in such regard. In the event persons owning the required percentage interest in and to the unit area have not so signed, ratified or approved the plan of unitization within a period of six months from and after the date on which the order creating the unit is made, the order creating the unit shall cease to be of further force and effect and shall be revoked by the supervisor.