A Pacific Gas & Electric Co. pipeline exploded in San Bruno, Calif., this month. The company reported 38 leaks along about 1,000 miles of line it controls near population centers or environmentally sensitive areas since 2004, an analysis of federal records by the Times showed.
The newspaper also said while most large gas suppliers are reporting fewer leaks on "high-consequence" gas lines, PG&E reports are climbing.
PG&E reported 6.2 leaks annually per 1,000 miles of line, more than six times the average leak rate for the nation's six other large operators, the newspaper said.
Federal regulators said the number of transmission line leaks reported nationally in populated areas has dropped more than 30 percent in recent years, while PG&E's reported leaks climbed about 40 percent, from 4.7 per 1,000 miles of line.
In a letter to the newspaper, PG&E officials questioned the comparability of federal data because other companies might use different criteria in determining what to report. The company also said it is reporting more leaks than before, after meeting with government officials.
"Assuming the numbers are a reasonable representation of the situation, obviously I and this commission would find them deeply disturbing," said Michael Peevey, president of the California Public Utilities Commission. "They may indicate a more systemic problem at PG&E."
California's other large operator, Southern California Gas Co., reported leaks of 2.3 per 1,000 miles.
The source of the gas leak in the explosion just south of San Francisco is not yet known, but the fireball and ensuing fire burned or damaged more than 50 homes, and caused about $65 million in damage, the newspaper said.