Following last week’s pipeline explosion in California that killed at least four people and destroyed 58 houses in suburban San Bruno, regulators have been searching for clues about what caused the blast. A piece in the Associated Press, meanwhile, suggests that thousands of pipelines like the one in San Bruno are aging and nearing their life expectancy:
Experts say the California disaster epitomizes the risks that communities face with old gas lines. The pipe was more than 50 years old — right around the life expectancy for steel pipes. It was part of a transmission line that in one section had an "unacceptably high" risk of failure. And it was in a densely populated area.
… Thousands of pipelines nationwide fit the same bill, and they frequently experience mishaps. Federal officials have recorded 2,840 significant gas pipeline accidents since 1990, more than a third causing deaths and significant injuries.
More than 60 percent of the nation’s gas pipelines are 40 years or older, AP reports. And age isn’t the only issue. Older pipelines are often configured in such a way that they’re unable to accommodate the latest pipeline safety technology.
Both The Wall Street Journal and Los Angeles Times have reported, for instance, that the pipeline itself was unusually built. The Times noted that the ruptured San Bruno pipeline, which was installed in 1956 by Pacific Gas & Electric Co., was so old and oddly configured that it could not accommodate a new pipeline-testing device known as a “pig,” which is considered to be “superior to other forms of testing.”
"It's the best way to test," a former head of the government's pipeline oversight agency, told the Times. Other testing methods “can miss things that the pigs would not miss," he said, including "tiny, tiny losses" in the thickness of pipeline walls. The former official, Cesar De Leon, also told the Times that because replacing these older pipelines in order to accomodate the pigs would be so costly, owners aren't required to do so.
According to PG&E President Chris Johns, the section of the pipe that exploded did not have such a device, but the testing methods used by the company do not “have any less capability.” He told reporters that the ruptured pipe was inspected twice in the past year, and those inspections turned up no problems.
As we’ve noted, the Pipeline and Hazardous Materials Safety Administration, the federal agency that regulates 2.3 million miles of oil and natural gas pipelines, largely relies on standards written by the oil and gas industry. It has about 100 inspectors, leaving industry a great deal of latitude with inspections. (Even after the blast, state utility regulators ordered PG&E to inspect its own network of gas pipelines.)
And according to The Washington Independent, federal regulators are required to inspect only about 7 percent of the country’s natural gas pipelines. That percentage is based on how populated the surrounding area is, and not the actual conditions of the pipelines.