"SAN BRUNO, Calif. -- State regulators have uncovered evidence that suggests Pacific Gas and Electric Co. installed 'salvaged or junked transmission pipe' on its natural-gas system in the 1940s and '50s, raising fears that a problem like the one that caused the San Bruno disaster could be lurking undetected, officials said in a regulatory filing Wednesday.

The California Public Utilities Commission's investigation of PG&E's record-keeping problems before the September 2010 pipeline explosion in San Bruno that killed eight people has uncovered 'documents that appear to demonstrate PG&E's historic reuse of salvaged or junked transmission pipe,' according to the filing by commission attorney Robert Cagen.

'These documents clearly raise serious safety concerns,' Cagen wrote."

Jaxon Van Derbeken reports for the San Francisco Chronicle October 20, 2011. [2]