More doubts arose Thursday regarding Pacific Gas and Electric Co.’s (PG&E) transmission pipeline testing as it related to its main link (Line 300) to Southwest natural gas supplies at the Arizona border. A California Public Utilities Commission (CPUC) hearing is set for Monday on the utility’s request to restore Line 300’s maximum allowable operating pressure (MAOP).
Local news reports in the San Francisco Bay Area indicated that CPUC safety staff was critical of PG&E testing of a suction pipe on the intake side of its California border receipt point at Topock Compressor Station. However, a PG&E spokesperson in San Francisco told NGI the staff was still recommending that eventually the combination utility be allowed to restore the MAOP.
PG&E has had the operating pressure lowered on Line 300 and nearly a dozen other pipelines since earlier this year when the CPUC ordered it to do so in the wake of the investigations following the San Bruno (Line 132) transmission pipeline rupture and explosion in September 2010.
News reports talked about the CPUC Consumer Protection and Safety Division (CPSD) staff calling PG&E’s testing “substandard” in trying to support the restoration of the MAOP. PG&E’s spokesperson said the regulatory staff did not have any problem with the testing that was done; instead, it was concerned that the utility did not do another test that quickly raises the pressure in a pipe to see how it withstands the “spike.”
In addition, no testing has been done on the California side of the compressor station in the parts of Line 300 carrying supplies away from the border and on to PG&E’s citygate about 500 miles to the northwest.
As far as the pipe on the east side of the compressor station where the Southwest supplies are received, PG&E completed a full hydrostatic test. The pipeline passed, but as often happens, a number of leaky valves developed, all of which the utility repaired, according to the utility spokesperson. “The full test was taken and the pipe passed it.
“What we didn’t do is a ‘spike test’ where you boost the pressure up, at least for a few minutes,” said the spokesperson. “The other side [in California] we have not yet done.”
A letter dated last Monday from interim CPSD Director Michelle Cooke clarified the CPUC action earlier this month and outlined what is needed from the utility. Cooke’s letter noted that PG&E did not conduct a 5% spike test above a recommended threshold. She said this was contrary to what CPSD and the PG&E had agreed would be completed.
“Despite the deficiencies noted, as described below, the hydrostatic tests conducted by PG&E, on pipeline facilities subject to the request, provide adequate assurance of the fitness for operation of these facilities,” said Cooke, although she later questioned why the PG&E hydrostatic testing contractor did not identify the spike test deficiencies.
“The deficiencies noted raise issue for PG&E’s hydrostatic testing program that must be remedied promptly,” Cooke said. She said hydrostatic testing going forward “must” include hydrostatic spike tests.
“It is important that PG&E justify to this commission and the public that the requested pressure restorations are safe,” said Commissioner Mike Florio last Thursday when regulators denied a request from PG&E to have CPUC Executive Director Paul Clanon approve raising the MAOP on various pipe segments. “That is why we will only allow PG&E to do so through a public and transparent process and after PG&E has presented evidence that it’s the right thing to do.” That’s what Monday’s hearing is supposed to provide on Line 300’s MAOP request.
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