Cal. Health & Safety Code § 25270.8

Each owner or operator of a tank facility shall immediately, upon discovery, notify the Office of Emergency Services and the UPA using the appropriate 24-hour emergency number or the 911 number, as established by the UPA, or by the governing body of the UPA, of the occurrence of a spill or other release of one barrel (42 gallons) or more of petroleum that is required to be reported pursuant to subdivision (a) of Section 13272 of the Water Code.