Pacific Gas and Electric Co. (PG&E) said late 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.
The latest filing to the California Public Utilities Commission (CPUC) covers 258 miles of HCA pipeline; earlier monthly reports cumulatively covered about 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 Daily GPI, June 10).
Since June, PG&E and the state’s other major intrastate pipeline operators have been under CPUC orders to test or replace all pipe segments that have not been pressure tested. The action came following an independent panel set up to review the fatal San Bruno pipeline explosion issued a scathing report criticizing “numerous shortcomings” in pipe integrity management and operations at PG&E. That criticism has grown louder and broader since the Aug. 30 National Transportation Safety Board (NTSB) report (see Daily GPI, Aug. 31).
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.
Since the San Bruno explosion and some initial NTSB interim reports, PG&E has repeatedly been criticized for shoddy record-keeping and an uneven track record for its integrity maintenance program (see Daily GPI, Jan. 5). In the final NTSB report, the utility was accused repeatedly of “systemic failures” in its record-keeping and its safety and maintenance programs.
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.”
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