Some disturbing answers are already beginning to come in about what went wrong in last Thursday’s disastrous San Bruno natural-gas pipeline explosion. It took PG&E 106 minutes to shut off the manual valves that were continuing to fuel the fire as it destroyed 37 homes and damaged hundreds more, while killing at least four people.
Assemblyman Jerry Hill, D-San Mateo, issued a quick pledge to introduce legislation or work towards a regulatory requirement for PG&E to install automatic shut-off valves throughout its entire 5,724-mile gas transmission network. With automatic or remote-controlled shut-off valves, utility technicians could have been able to safely stop the inflowing gas within a few minutes.
The National Transportation Safety Board has begun investigating PG&E’s response in shutting down the pipeline valves. In 1982, the same safety authority called upon PG&E to improve its valve-closing procedures after a nine-hour gas leak in downtown San Francisco — which thankfully did not explode. The NTSB urged PG&E to provide better training on closing valves to a wide range of employees and ensure that all valves are inspected and operated annually.
Meanwhile, elected officials from the Bay Area are raising the pressure on PG&E to make public the location and maintenance status of its gas pipelines. Three San Francisco supervisors introduced separate resolutions demanding the information. Assemblyman Hill and U.S. Rep. Jackie Speier want PG&E to release its list of the 100 most-vulnerable pipelines. U.S. Sens. Dianne Feinstein and Barbara Boxer are calling for an investigation of all interstate gas pipelines in California.
The City’s Department of Emergency Management, Fire Department, Department of Public Works and Public Utilities Commission have all said they do not have maps of PG&E’s pipelines, despite federal regulations obligating utility operators to turn over this information.
Federal officials have tallied 2,840 significant gas-pipeline accidents since 1990, more than a third causing death or serious injuries. Congress passed a law in 2002 that for the first time requires utilities to inspect pipelines passing through heavily populated locations. In the law’s first five years, more than 3,000 problems were found.
It is vitally important that we uncover everything possible about what caused the San Bruno pipeline explosion so that we can better protect ourselves against future gas conflagrations. But the U.S. is traversed by more than 300,000 miles of large gas transmission pipelines and approximately 21,000 miles of those are beneath high-population areas. The total of all U.S. pipelines is estimated as well over two million miles.
So it’s easy to understand that improving the system’s safety is a dauntingly huge project. However, at least the San Bruno fireball has finally spotlighted the need to pay much more attention to natural-gas pipeline safety. At this early phase of what is sure to be a lengthy process of inspections, investigations, hearings and reports, it seems as if some practical first steps would be to work towards identifying the system’s weakest links — then fixing as many as possible, as quickly as possible and with maximum public transparency.