"In some cases some of these lines may not have ever been tested; they may have been tested by some other means," PG&E spokesperson Joe Molica said.
The pipelines targeted for the testing are the same type as the one that burst in a San Bruno neighborhood last year, killing eight people and destroying 38 homes.
"These are pipelines that were probably never tested; remember it was legal to do that back at the time when they were installed, so it's very important that these pipelines be tested, the sooner the better," California Public Utilities Commission Executive Director Paul Clannon said.
The Mountain View pipeline runs through the Sierra Vista residential neighborhood right next to homes and a playground.
The hydrostatic test will involve exposing the pipe and forcing water through at one and a half times the pressure the pipe is supposed to withstand. Leaks will be easily detectable.
"This is all part of our efforts to reassure the commission, reassure the public and ourselves that the pipeline are operating at the specific pressure that they're designed to operate at," Molica said.
TURN, a public utility watchdog group says the tests are long overdue.
"It's about time that they started properly testing these pipelines," TURN spokesperson Mark Toney said.
The CPUC is specific about who will pay for the testing. The ratepayers will not be paying for the testing because it is part of PG&E's obligation to make sure the pipelines are operating safely.
One of the reasons that PG&E does not know how or if these lines have been tested is that they have not found the paperwork for the 150 miles of pipeline the CPUC requested in January, so the tests have to be performed to comply with CPUC demands for safety checks of lines like the one in San Bruno.
