Officials for a California utility have acknowledged the company wrongly classified hundreds of miles of natural gas transmission lines of the same type that ruptured in a deadly explosion in a San Francisco suburb.
Pacific Gas & Electric Co. filed a document with state regulators Tuesday saying that it misclassified more than 300 miles of lines, and as a result ran some segments at higher pressure than recommended by federal authorities.
California regulators ordered PG&E to review lines running through densely populated areas after the Sept. 9, 2010, blast, which killed eight people and destroyed 38 homes in San Bruno.
Federal law requires utilities to perform more stringent inspections on lines in highly populated areas. The company said in June that it failed to properly classify 172 miles of pipelines.