Following the Sept. 9 explosion and fire in San Bruno, PG&E had already reduced the operating pressure on the three transmission lines that serve San Francisco and the Peninsula as a precaution. But Thursday, from the Public Utilities Commission ordered PG&E to reduce by 20 percent the pressure for pipelines in high consequence areas. Specifically, the utility must reduce the pressure in lines measuring 30 inches in diameter and installed before Jan. 1, 1962 in areas where there are lots of homes and businesses.
PG&E says that applies to only two transmission lines, both in the East Bay.
"One that runs from Oakland to Fremont and another that runs from Fremont to Milpitas. Basically what that means is a 20 percent reduction in that pressure will restrict the ability of gas to go through those lines as a precaution," PG&E spokesperson Joe Molica said.
Less pressure will affect the amount of gas that goes into people's homes and that has The Utility Reform Network Executive Director Mark Toney concerned.
"Gas requires pressure to move it into people's homes and if there is a cold spell this could be a big problem and people completely left without heat," Toney said.
But Molica says PG&E is prepared for cold days when usage goes up PG&E will rely on their non-core clients (large industrial customers) to conserve.
"A lot of the non-core customers on the gas side enjoy a lower rate throughout the year and in turn they agree on very cold winter days they will curtail their usage," Molica said.
PG&E has also been ordered to inspect the integrity of the pipelines and until it does so the gas transmission lines will remain at 20 percent below the allowable operating pressure.