For the purposes of environmental compliance, CAL FIRE is the agency that is responsible for the Above Ground Petroleum Storage Act (APSA). Most of the enforcement authority has been delegated to the local Unified Program Agencies (UPAs).
For a broader perspective you can read from their website:
The Office of the State Fire Marshal supports the mission of the CAL FIRE by focusing on fire prevention. The Office of the State Fire Marshal provides support through a wide variety of fire safety responsibilities including: regulating buildings in which people live, congregate, or are confined; by controlling substances and products which may, in and of themselves, or by their misuse, cause injuries, death and destruction by fire; by providing statewide direction for fire prevention within wild-land areas; by regulation hazardous liquid pipelines; by developing and reviewing regulations and building standards; and by providing training and education in fire protection methods and responsibilities.
These achievements are accomplished through several major program elements including engineering, education, enforcement and support from the State Board of Fire Services.