Fire raises questions about transmission line safety

September 11, 2010

As investigators search for clues to Thursday night’s devastating San Bruno fire, questions are being raised about the safety of natural gas transmission lines maintained by PG&E. [LA Times]

Four people were killed, dozens were injured, and 37 homes were destroyed Thursday night after a gas pipeline exploded in the San Francisco suburb.

Residents say they had smelled gas for several days prior to the explosion.

PG&E officials vowed to cooperate with the federal investigation, but did not say whether the company’s pipeline caused the San Bruno explosion.

“It does everyone a disservice to point fingers before any investigation of the facts has even begun,” said PG&E spokesman Andrew Souvall.

The explosion occurred as PG&E and other pipeline operators are working to comply with a costly, federally mandated inspection and safety management program.

According to experts who monitor federal and state agencies for ratepayer groups, PG&E was required to inspect half of its transmission pipelines by the end of 2008 and the other half by the end of 2012. The utility also was expected to carry out a regular re-inspection program.

“We don’t know what the status of the project is,” said William B. Marcus, a utility economist who works for the Utility Reform Network on PG&E rate matters before the California Public Utility Commission. “But we do know that PG&E has been spending” millions annually to get the inspection program completed.

PG&E has had  problems with a program to inspect leaks in its extensive distribution network stretching from the California-Oregon border to Bakersfield, according to a company report and industry watchdogs.

Distribution pipes, which deliver natural gas to neighborhoods and individual homes, are smaller in diameter and operate under less pressure than giant transmission pipes such as the one that exploded in San Bruno.

“PG&E’s gas leak detection program failed miserably earlier this decade,” Marcus, whose group advocates for ratepayers, wrote in a report to the California Public Utilities Commission (PUC) in June.

Marcus said he was able to gain some insight into the program’s difficulties because the state PUC released a PG&E PowerPoint presentation on the program.

The presentation noted that a 2007 re-survey of leaks in the North Coast Division “found deficiencies” including “record falsification” in earlier surveys performed in 2004-07. At one point, the survey had to be “suspended” and all personnel retrained.

A 2008 leak survey showed better results, PG&E said. However, the report concluded that “system-wide improvements are needed in leak survey” including in the areas of “leak grading process, standards, controls training and operator qualification.”

The official report concerning the cause of Thursday night’s fire isn’t expected before early next year.