Crews with Pacific Gas and Electric found leaks on main gas pipelines and other facilities in California that required immediate repair, the utility said.
PG&E said it conducted surveys of its gas transmission system in California and found 300 locations that were suitable for upgrades and scores of other anomalies that required immediate repair.
A natural gas pipeline burst Sept. 9, sparking a massive fireball that ripped through a San Bruno, Calif., neighborhood. The explosion killed seven people and destroyed 37 homes.
The U.S. National Transportation Safety Board in a preliminary report found an electrical failure at a PG&E facility caused a pressure surge in the pipeline just before the San Bruno explosion
Kirk Johnson, vice president of gas operations at the utility company, said his company was working diligently to examine its gas transmission pipeline system in California in the wake of the tragedy.
"Today's filing shows how much progress we have made in a short period of time but also points to the significant work still ahead of us," he said in a statement.
The company said it examined close to 16 miles of transmission pipeline in San Bruno and found no integrity issues that required immediate repair.
Five lawsuits filed against the company call for unspecified damages and call on PG&E to remove the idled pipeline from their San Bruno neighborhood.