While trying to deflect regulatory attorneys’ allegations of “significant safety issues” with one filing to the California Public Utilities Commission (CPUC) Monday, Pacific Gas and Electric Co. (PG&E) separately asked the CPUC to allow it to raise pressure on three key natural gas transmission pipeline links on the San Francisco peninsula. It also submitted a monthly report indicating that it is nearing the completion of the hydrostatic testing of top-priority pipe segments in highly populated areas.

The three separate submittals to the CPUC raised again the profile of the San Francisco-based combination utility and its beleaguered transmission pipeline system, which still has months, if not years, of work to answer federal and state regulatory critics who have alleged that poor safety and maintenance led to last year’s rupture and explosion in San Bruno, CA (see Daily GPI, Aug. 31).

PG&E said it made its filing in response to the CPUC Legal Division to make public its contention that there is “nothing in [83] documents” reviewed by the regulatory attorneys that “raises any current safety concern.” The utility said the conditions the CPUC lawyers called attention to are already being addressed by PG&E in its safety programs.

As an outgrowth of those programs, PG&E separately asked for the lifting of operating pressure restrictions on transmission pipe going south to north from the San Jose area to San Francisco. The utility wants by Dec. 15 to re-establish maximum operating pressure (MOP) of 365 psig in Line 101, Line 132A and Line 147, while reestablishing the maximum allowable operating pressure (MAOP) at 396 psig, which would still be lower that the MAOP effective at the time of the San Bruno explosion, which exceeded 400 psig.

Line 101 generally runs the entire length of the west side of San Francisco Bay from Milpitas near San Jose to a point in the city of San Francisco, and Lines 132A and Line 147 are crossover links between Lines 101, 109 and 132, the last being the 30-inch diameter pipeline on which a segment failed in a residential neighborhood of San Bruno. Pressure was dropped by 20% in each of these lines following the explosion at the direction of the CPUC and through voluntary actions by PG&E.

“PG&E needs to return Line 101 and the cross-ties to normal operation to avoid potential curtailments this winter of our core customers in San Francisco and all noncore customers [including hospitals and other critical facilities] on the peninsula,” the utility said in its CPUC filing.

“If Line 101 must be maintained at its current reduced operating pressure of 300 psig, PG&E faces potential significant operational and customer impacts. Last winter proved to be relatively mild and PG&E was able to continue to serve its customers at the reduced pressure [but] we cannot count on being similarly lucky this coming winter.”

Finally, in a monthly status report on its ongoing hydrostatic testing and pipe segment replacement program, PG&E reiterated its public announcement last week of its first test failure and pipeline segment replacement on a portion of the major transmission pipeline bringing supplies from the Southwest at the California-Arizona border to load centers in central and northern parts of the state (see Daily GPI, Oct. 28).

Aside from the single failed test, PG&E said it now has verified 125 of 152 miles of transmission pipeline that were designated as top priority for safety verification work. Those 125 miles were either successfully hydrostatically tested and tied in, successfully tested but not yet tied in, replaced, or had strength test pressure records verified.

PG&E said that as of Monday it had completed hydrostatic tests and returned those sections to service for 54 test segments and replaced two test sections, totaling 73.7 miles of transmission pipeline. In addition, the utility completed strength test pressure records verification for 26 other test sections, representing 42.2 miles of high-pressure transmission pipeline.

Among the 54 segments for which the hydrostatic tests have been successfully completed, 28 involved portions of Line 300A and B, which is the transmission line bringing Southwest basin gas supplies from the Arizona-California border. Nevertheless, PG&E has not gone back to the CPUC seeking to have the pressure restrictions lifted on Line 300.

PG&E said it plans to complete up to 19 additional hydrostatic test sections in November, involving the testing of 150 miles of pipeline with what the utility called a “very aggressive and complex schedule.”

©Copyright 2011Intelligence Press Inc. All rights reserved. The preceding news reportmay not be republished or redistributed, in whole or in part, in anyform, without prior written consent of Intelligence Press, Inc.