Pacific Gas and Electric Co. (PG&E) documents have shown that a gas transmission line running through Stanford’s campus and Palo Alto contains at least 22 feet of salvaged pipe dating back to 1947.

The announcement touched a nerve following the Sept. 2011 San Bruno incident that killed eight people when a 30-inch-diameter natural gas pipeline on Line 132 owned by PG&E exploded out of the ground in flames.

California Public Utilities Commission (CPUC) lawyers accused PG&E in an Oct. 19 filing of knowing about faulty seams dating back to 1948 and practicing reckless use of salvaged, reused pipe.

In an Oct. 20 response to CPUC’s filing, PG&E confirmed that the 22 feet of salvaged pipe does date back to 1947. The company said it would be hydro-testing this section of pipe this year.

The exact amount of reused and salvaged pipe is difficult to determine based on the series of documents recording the company’s renovations over the past half-century.

A Jan. 1, 1957, construction drawing indicated that Line 132, the same pipeline as the San Bruno incident, was relocated along Page Mill Road between Junipero Serra Boulevard and El Camino Real. Transmission pipe was salvaged from the relocation, but its next use remains unclear, along with whether salvaged pipe was reconditioned before use in several cases.

The documents suggest that most salvaged and reused pipe was used on Lines 131 and 132, near Morgan Hill and San Bruno. The Morgan Hill pipe, however, was taken out of commission in 1970, and its pipe was salvaged and reused in Milpitas.

On Friday, PG&E announced that it found a leak during hydro-testing of pipe near Palo Alto. The company did not clarify whether the leak is located in the reused section of the pipeline.

On Sunday, a pipeline in Woodside, Calif., burst while PG&E was conducting hydro-testing in the region. The section of pipe that ruptured was on Line 132. No injuries were reported, while one vehicle was damaged by the spray of dirt and rocks resulting from the rupture.

– Margaret Rawson