Pacific Gas and Electric Co. (PG&E) last Tuesday asked California regulators for more time to produce full documentation on welds and flaws uncovered during the past 55 years on 1,805 miles of its natural gas transmission pipeline system. A regulatory commission judge is scheduled to hold a prehearing conference on the utility’s request Monday (June 6).

Separately, Sempra Energy’s San Diego Gas and Electric Co. (SDG&E) last week outlined efforts to step up safety and maintenance of its pipelines system.

PG&E has struggled all year with deadlines and requests for information as part of a California Public Utilities Commission (CPUC) investigation following the rupture last year of one of the utility’s transmission pipelines in San Bruno, CA.

“[We] share the commission’s important goal of further enhancing the safety of our system, and natural gas systems throughout the state,” said a PG&E spokesperson, noting that PG&E is providing voluminous amounts of information and documents to CPUC’s Division of Safety and Consumer Protection. “We intend to provide as much information as possible by the June 20 deadline, and we are asking for some more time to provide additional documents.”

PG&E has been under increased pressure since the CPUC held a show-cause hearing in response to what it considered the utility’s lack of compliance with ongoing state and federal investigations of the Sept. 9 pipeline rupture (see NGI, March 28).

PG&E’s lawyers told state regulators in a filing last Tuesday that it had “seriously underestimated the magnitude of the task,” particularly in light of its field testing of various pipeline segments to verify those segment’s current maximum allowable operating pressures (MAOP).

In the spotlight is the utility’s need to produce “all” documents pertaining to “all weld defects or failures” in the nearly 2,000 miles of transmission pipelines that pass through heavily populated areas categorized as Class 3 and 4 and Class 1 and 2 high-consequence area (HCA) pipelines.

The CPUC later this month is expected to require all California operators of intrastate natural gas transmission pipelines to prepare implementation plans to pressure test or replace all pipeline segments that have not been tested or lack sufficient records verifying such tests (see NGI, May 16). Regulators are expected to adopt a proposed decision released last month by Administrative Law Judge (ALJ) Maribeth Bushey.

In the meantime, SDG&E said it has begun retrofitting segments of a 51-mile transmission pipeline that stretches from Rainbow to San Diego’s Miramar area in north-central San Diego County. “This retrofit will include installing pipe supports, fittings and valves that will enable a sophisticated sensor to traverse the pipeline’s interior,” a Sempra utility spokesperson said.

The work is expected to take about nine months, stretching into March next year. SDG&E is planning major excavations in six locations in San Diego County.

Sempra’s other California utility, Southern California Gas Co. (SoCalGas), the nation’s largest gas distributor, has been doing similar work on its extensive transmission pipeline system, according to a Sempra utility spokesperson. The work involves retrofitting major transmission lines with equipment needed to allow for inline inspections, or “smart pigging” of the lines, the spokesperson said.

“[SoCalGas] retrofitting of pipelines to make them piggable has been going on since 2003,” said the spokesperson, who noted that the work involves replacing existing valves and fitting that don’t accommodate the smart pig. “We have a pipeline right now that we are retrofitting to allow for inline inspection.”

PG&E told the CPUC last Tuesday that it will produce “a substantial quantity of documents” for HCA pipelines and a “smaller volume” of data on the non-HCA lines on June 20. One of the problems is that the utility does not maintain a single type of record that specifically pertains to gas pipe weld failures or defects before and after the use of those pipes. Instead, it maintains a combination of numerous documents related to inspections, testing, repairs and other situations.

Besides the information that PG&E has generated during the past 55 years, it also must review mill inspection and test report documents from the manufacturers of the pipelines in terms of pre-use records. The post-use records are mostly developed as part of leak repairs and integrity management program inspections.

In asking for more time, but not specifying another date, PG&E told the CPUC it does not want the records search related to weld and defect information to “compete with” the MAOP validation process, which is ongoing and scheduled to be finished at the end of next year.

While expanding SDG&E’s customer reminders regarding precautions in digging around gas pipelines and calling with reports of gas odors, the utility said it was developing a new distribution pipeline integrity management program to include:

The latter is called a “crossbore,” and SDG&E said their occurrence is rare, but the utility has started a five-year safety inspection program in areas that would be most likely to experience the phenomenon. SDG&E said it estimates crossbores could potentially impact about 6% of its 850,000 gas utility customer base.

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