Pacific Gas and Electric Co. (PG&E) said last Monday it has completed the first part of its pipeline pressure validation effort, completing verification of the maximum allowable operating pressure (MAOP) for 750 miles of transmission pipeline running through heavily populated urban areas known as “high-concentration areas” (HCA). PG&E said it made its last monthly report on the initial validation effort to state regulators.

Still unresolved, however, is the utility’s request to restore the MAOP on its transmission pipeline link to Southwest gas supplies at the Arizona border. The California Public Utilities Commission (CPUC) will hold a hearing Monday (Sept. 19) to have PG&E present its case for Line 300, which has still not completed hydrostatic and other testing, according to both the utility and CPUC.

In the completed validation test filing to the CPUC, PG&E covered 258 miles of HCA pipeline; earlier monthly reports cumulatively covered another 500 miles of HCA pipe segments similar to the 30-inch diameter section of Line 132 that ruptured last September in San Bruno, CA.

As it continues a separate effort to hydrostatically test, repair and/or replace segments of its 6,000-mile transmission system, PG&E said it has finished the initial engineering and record review it agreed to complete with the CPUC’s Consumer Protection and Safety Division (CPSD). At CPSD’s urging, the utility agreed to validate safe pressure levels in pipelines that were lacking a prior hydrostatic test (see NGI, June 13).

Doubts continued to swirl around the Southwest supply line last Thursday as news reports indicated that CPUC safety staff was critical of PG&E testing of a suction pipe on the intake side of its California border receipt point at Topock Compressor Station. However, a PG&E spokesperson in San Francisco told NGI the staff was still recommending that eventually the combination utility be allowed to restore the MAOP.

PG&E has had the operating pressure lowered on Line 300 and nearly a dozen other pipelines since earlier this year when the CPUC ordered it to do so. News reports talked about the CPSD staff calling PG&E’s testing “substandard” in trying to support the restoration of the MAOP. PG&E’s spokesperson said the regulatory staff did not have any problem with the testing that was done; instead, it was concerned that the utility did not do another test that quickly raises the pressure in a pipe to see how it withstands the “spike.”

In addition, no testing has been done on the California side of the compressor station in the parts of Line 300 carrying supplies away from the border and on to PG&E’s citygate about 500 miles to the northwest.

There was no immediate response from the CPUC or its safety unit regarding the latest filing by the San Francisco-based combination utility, which last month filed a four-year, nearly $2 billion plan for verifying MAOP and safety/maintenance needs of the bulk of its high-pressure transmission pipelines.

PG&E’s new executive vice president in charge of the utility gas system, Nick Stavropoulos, said there is “more work” for PG&E to do to begin to get its natural gas operations in order. Part of that will be to continue “aggressive MAOP validation efforts” for the rest of its HCA pipe as well as all of its other transmission pipeline.

The utility said it has hired new employees and engaged outside experts to meet new standards for pipeline data and pressure validations. PG&E has more than 300 full-time workers assigned to the project, and those employees are supplemented by a team of program management, information technology and quality assurance personnel.

On the unresolved Line 300 situation, PG&E completed a full hydrostatic test on the pipe on the east side of the border compressor station where the Southwest supplies are received. The pipeline passed, but as often happens, a number of leaky valves developed, all of which the utility repaired, according to the utility spokesperson. “The full test was taken and the pipe passed it.

“What we didn’t do is a ‘spike test’ where you boost the pressure up, at least for a few minutes,” said the spokesperson. “The other side [in California] we have not yet done.”

A letter dated last Monday from interim CPSD Director Michelle Cooke clarified the CPUC action earlier this month and outlined what is needed from the utility. Cooke’s letter noted that PG&E did not conduct a 5% spike test above a recommended threshold. She said this was contrary to what CPSD and the PG&E had agreed would be completed.

“Despite the deficiencies noted, as described below, the hydrostatic tests conducted by PG&E, on pipeline facilities subject to the request, provide adequate assurance of the fitness for operation of these facilities,” said Cooke, although she later questioned why the PG&E hydrostatic testing contractor did not identify the spike test deficiencies.

“The deficiencies noted raise issue for PG&E’s hydrostatic testing program that must be remedied promptly,” Cooke said. She said hydrostatic testing going forward “must” include hydrostatic spike tests.

“It is important that PG&E justify to this commission and the public that the requested pressure restorations are safe,” said Commissioner Mike Florio on Sept. 8 when regulators denied a request from PG&E to have CPUC Executive Director Paul Clanon approve raising the MAOP on various pipe segments. “That is why we will only allow PG&E to do so through a public and transparent process and after PG&E has presented evidence that it’s the right thing to do.” That’s what Monday’s hearing is supposed to provide on Line 300’s MAOP request.

As part of its ongoing testing efforts regarding MAOPs on various pipeline segments, PG&E has reduced pressures on a dozen different pipelines to provide an “additional margin” of safety. “[We] will further ensure the safety of the system by conducting hydrostatic pressure tests, performing validation tests and inspections and replacing pipeline as needed,” it said.

Stavropoulos said the milestone of completing the pressure verification work on the first 750 miles of the most critical of its pipeline segments “enhances the safety of our gas pipeline system.”/p>

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