California Code, Public Utilities Code - PUC § 958

(a) Each gas corporation shall prepare and submit to the commission a proposed comprehensive pressure testing implementation plan for all intrastate transmission lines to either pressure test those lines or to replace all segments of intrastate transmission lines that were not pressure tested or that lack sufficient details related to performance of pressure testing.  The comprehensive pressure testing implementation plan shall provide for testing or replacing all intrastate transmission lines as soon as practicable.  The comprehensive pressure testing implementation plan shall set forth criteria on which pipeline segments were identified for replacement instead of pressure testing.

(b) The comprehensive pressure testing implementation plan shall include a timeline for completion that is as soon as practicable, and includes interim safety enhancement measures, including increased patrols and leak surveys, pressure reductions, prioritization of pressure testing for critical pipelines that must run at or near maximum allowable operating pressure values that result in hoop stress levels at or above 30 percent of specified minimum yield stress, and any other measure that the commission determines will enhance public safety during the implementation period.  Engineering-based assumptions may be used to determine maximum allowable operating pressure in the absence of complete records, but only as an interim measure until such time as all the lines have been tested or replaced, in order to allow the gas system to continue to operate.

(c) At the completion of the implementation period, all California natural gas intrastate transmission line segments shall meet all of the following: