Cal. Gov. Code § 51016
The State Fire Marshal shall study the spacing of valves which would limit spillage into standard metropolitan statistical areas and environmentally sensitive areas from surrounding higher ground. If any existing pipeline system's valve spacing is deemed insufficient to protect California's uniquely situated population centers and environmental resources, the State Fire Marshal shall adopt regulations to require the addition of valves on existing pipelines. If the study indicates that guidelines for valve spacing do not, in the State Fire Marshal's opinion, adequately protect these population centers and environmental resources, the State Fire Marshal may adopt regulations to require new valves on new, existing, or replacement pipelines as necessary to protect the public interest.
Ca. Gov. Code § 51016