California Code, Public Utilities Code - PUC § 4454

(a) Every operator of a system serving 10 or more units or where any portion of the system is located in a public place, with the exception of mobilehome parks operators, shall prepare and submit to the commission annually a report on the distribution system. The report shall be submitted by March 31 of each year and shall cover the previous calendar year.

(b) In the case of mobilehome parks, the report shall be submitted to the commission at the same time the annual application for a permit to operate the mobilehome park is submitted to the department or the local enforcement agency.

(c) The report shall be prepared using a form or forms required by the commission, and shall contain the information the commission finds necessary to carry out the intent of this chapter. In developing the form or forms, the commission shall consult with interested parties to ensure that the form contains no more than the necessary and appropriate information to carry out the intent of this chapter.

(d) Upon receipt of the report, the commission shall examine the report for violations of either applicable federal pipeline safety laws or regulations or any applicable commission rules or orders. The commission may inspect the operator's distribution system for the purpose of verifying whether or not a violation of federal or state pipeline safety laws or regulations, or NFPA 58 rules, has occurred or is occurring.