Lack of maintenance--not nearby sewer construction--is the main factor in the September 2011 San Bruno natural gas explosion, according to attorneys for the city. An independent investigation “fails to address” pipeline owner Pacific Gas & Electric’s “serious corporate and engineering failures,” according to the attorneys on July 14. Some of the conclusions in the panel’s report to the California Public Utilities Commission are “diversionary,” noted attorneys. They encouraged regulators to develop a historical review of pipeline system pressures and called the theory that a 2008 sewer project in the area contributed to the explosion “wholly speculative.” PG&E responded it “agrees in full spirit with the panel’s overall conclusions” in its filing. A day later, the commission ordered PG&E to, among other things, provide the state with inspection records on shut off valves and give fire agencies maps of pipelines and valves.
