The Bell Law Firm, PLLC

In our Sept. 8 post, we started talking about the National Transportation Safety Board's final report on the San Bruno gas pipe explosion. The accident leveled a neighborhood and killed eight people. The systemic failures that led up to the accident are all too reminiscent of West Virginia's Upper Big Branch disaster.

As we said, the NTSB called the blast an "operational accident." The report finds fault with both the state regulatory agency and the utility -- and the problems date back to the 1950s.

The utility's inspection programs and record-keeping were particularly brought to task. The company had a hard time finding any records at all, especially records related to the source and installation of the pipe that exploded.

Investigators discovered that the pipeline had been seam-welded, but the records said there were no welds. The records also showed that the pipeline in the San Bruno area was of uniform thickness. Investigators found otherwise -- the thickness was variable.

Seam-welding and thickness are not small issues. Both factor into the amount of internal pressure a pipe can withstand. Pacific Gas & Electric set the maximum pressure at 400 pounds per square inch. The pipe reached 396 pounds before it failed.

The board said, too, that PG&E's risk assessment process was incomplete. The utility focused too much on dangers posed by ground movement (in the earthquake-prone region) and excavation near pipelines. Under-represented were issues with corrosion of the pipeline or manufacturing flaws -- like the bad welds that ruptured in San Bruno.

This is a small sample of the issues the NTSB pointed out. According to the report, PG&E could not locate pressure tests for more than two-thirds of the transmission lines that were laid before 1961. Record-keeping and safety measures go hand-in-hand at times. During the year the board has been investigating the blast, they have made 40 recommendations to PG&E.

We'll cover the problems the NTSB identified at the regulatory level in our next post.

Source: Charleston Post & Courier, "NTSB faults PG&E, regulators in gas explosion," Joan Lowy and Matthew Brown, Aug. 31, 2011