This 2009 map shows the network of major U.S. natural gas pipelines, which serve about half of U.S. homes.
Almost two-thirds of America’s natural gas pipelines — including the 30-inch main that exploded last week in San Bruno, Calif. — are susceptible to potentially deadly faults because they can’t use the industry’s best technology for testing and cleaning them, federal records show.
The 2½-foot-wide gas main exploded Thursday night, killing at least four people, injuring dozens more and destroying scores of homes. The California Public Utilities Commission has ordered an inquiry and told Pacific Gas and Electric Co., the utility that owned and operated the pipe, to inspect all of the state’s gas pipelines for potential problems.
PG&E says it’s still too early to know why the pipe blew up. But disclosures since the blast make it clear that a trifecta of vulnerabilities meant the San Bruno main was prone to fail sooner rather than later:
•It was 54 years old, at the outer limit of its expected 50-year lifetime.
•It was made of steel. As msnbc.com reported last week regulators have long regarded steel — which is used in about half of all gas pipelines and nearly two-thirds of the nation’s larger gas mains — as a safety hazard because it’s too rigid and easily corrodible.
•Because of the gas main’s age and the twists and turns of the pipeline, PG&E couldn’t use robots that would have been the best way to maintain and inspect it.
http://www.msnbc.msn.com/id/39174246/ns/us_news/