California Code, Public Utilities Code - PUC § 4456

(a) If the commission determines the presence of a propane leak or other safety hazard in the distribution system, which poses a significant or immediate danger to the health and safety of the distribution system's customers, it shall notify the supplier serving the distribution system; the operator, who shall provide notice to the affected customers; and local authorities, as deemed necessary.

(b) The commission shall require the operator to take immediate steps to correct and repair the propane leak or other hazard. The operator of a mobilehome park shall obtain permits from the department or local enforcement agency, as required by Part 2.1 (commencing with Section 18200) of Division 13 of the Health and Safety Code. Other operators shall obtain permits from local agencies, such as the county or fire district. The commission may place a warning tag on the tank, may direct the serving supplier to terminate service to the tank, and may direct other local suppliers not to serve the tank, if an operator does not comply with this requirement. The cost of repair or corrective action shall be borne by the operator.