A gas-transmission line that runs through Palo Alto and Stanford University contains at least 22 feet of reused, salvaged pipe dating to 1947, according to PG&E documents.
California Public Utilities Commission lawyers blasted PG&E for its use of salvaged pipe in an Oct. 19 filing and accused the company of knowing about faulty seam welds dating to 1948.
The reuse of salvaged pipe has also come under scrutiny by the National Transportation Safety Board, which is investigating the San Bruno incident that killed eight people in September 2010.
The CPUC legal department said documents that show reuse of salvaged pipe "raise serious safety concerns both for the future and for past safety, including the causes of the San Bruno pipeline rupture.
"The National Transportation Safety Board (NTSB) has been unable to certify the provenance of the ruptured pipe, or whether any pups that made up the pipe had previously been used elsewhere in PG&E's system. Moreover, we believe that PG&E cannot accurately certify that no other re-used and/or deficient transmission pipe remains in service."
Four records document the movement of 24-inch pipe in Palo Alto/Stanford when a section was being relocated starting in 1957. But none indicate the disposition of more than 2,500 feet of salvaged pipe in addition to the 22 feet that was reused. The documents do not indicate if the relocated pipe is new or reused.
A Jan. 1, 1957, construction drawing indicates that Line 132, which was the gas main that exploded in San Bruno and runs down the peninsula, was relocated along Page Mill Road between Junipero Serra Boulevard and El Camino Real.
Transmission pipe measuring 2,598 feet and 24 inches in diameter was salvaged from the relocation job. Another 22 feet was salvaged and reused. Salvaged pipe is often "credited" toward the cost of a project, as shown on several PG&E documents.
A May 7, 1957, progress report noted that 3,300 feet of 24-inch steel transmission main was to be installed and 3,260 feet of steel main was to be removed. The job "facesheet" noted the 1947 pipe was salvaged, but there is no indication it was reconditioned or reused, PG&E said.
A June 7, 1957, gas-main assignment letter assigns the relocation job of 3,300 feet of 24-inch pipe on Page Mill, to General Construction and notes: "Material to be drawn from the local warehouse," but it does not indicate that the pipe was reconditioned, PG&E noted in its response to the attorneys.
A March 18, 1960, credit-acquisition form shows 2,485 feet of pipe taken from the Palo Alto-Stanford pipeline segment was reconditioned. "There is no indication the reconditioned pipe was reinstalled on this job," PG&E noted.
Regarding the 22 feet of reused pipe, PG&E wrote in its Oct. 20 response to the CPUC that the pipe in Palo Alto dates from 1947:
"Based on other documents, it appears the 22 feet of pipe was not considered new pipe and is still labeled as 1947 pipe. PG&E is hydro testing this section of pipe this year," the company wrote.
On Friday (Nov. 4) PG&E announced that crews performing hydro tests near Palo Alto found a leak that is estimated to be about one millimeter in diameter. It is not known yet if the leak is located in the reused portion of pipe.
The four-mile test area contains nearly 21,000 feet of 24-inch seamless pipe that was installed in 1947. About 2,700 feet has a seam weld and was installed in 1957, PG&E said.
The leak does not pose a threat to the public and crews will take several days to pinpoint its location and do repairs and tests, according to spokesman Brian Swanson.
PG&E released more than 80 pages of documents to the public on Oct. 20 regarding five gas-transmission lines in the Bay Area that have come under scrutiny since the San Bruno tragedy.
Most of the documents pertaining to salvaged and reused pipe show it was reused on Lines 131 and 132 near San Bruno and Morgan Hill in 1956.
The Morgan Hill pipe was removed from service in 1970, according to PG&E. Pipe dating to 1930 was salvaged and reused on Line 107 in Milpitas in 1956. It was hydro-tested in 1977, according to the records.
None of the seam welds that PG&E found to be faulty in 1948 were in Palo Alto or Stanford, according to the documents. Those welds, which were defined as "cracked," occurred in San Bruno, Millbrae and Burlingame, according to PG&E records.
PG&E in its reply to the CPUC said that the reused, salvaged pipe and the issues pertaining to the 1948 welds are not new to PG&E or the industry.
The documents it has made public are the same as those given to the CPUC, except that it has redacted the names and contact information of non-management employees and specific locations of critical infrastructure, such as valves, the company said.
Each of the documents PG&E gave to the CPUC attorneys came with an attached confidentiality claim. The attorneys are asking the CPUC to allow them to make documents they have discovered available to the public. The CPUC will hear the attorneys' request on Nov. 10.