A stretch of 1.45 miles of pipeline, primarily beneath the Rex Manor neighborhood, will be filled with water today to determine the reliability of pipeline 132a, according to PG&E.
"This work is part of a massive undertaking to validate safe operating pressures for our gas transmission pipelines, verify our records and enhance the safety of our gas transmission system," said Brittany M. Chord, a PG&E spokeswoman.
Over this past weekend PG&E vented the gas out of the pipeline and put it into an alternate and temporary pipe. This process may have caused some residents to smell some gas but should not interrupt service.
Water, stored in containers on the golf course, started to be pumped in at 5 a.m. this morning. According to PG&E the work today will end at 1 p.m.
An electronic device will measure any changes in pressure for an eight-hour period. If pressure decreases, it would signify that a leak existed. If so, then the utility would replace the pipe along that segment. The replacement pipe would meet pressure tests.
Chord confirmed that this type of hydrostatic testing "is the industry standard," that "it's common practice" and that "nothing out of the ordinary" should happen.
"Following a successful test, the section of pipe is emptied of water, dried thoroughly and placed back in service," Chord said.
PG&E prioritized the pipelines to be tested based on similarities to Line 132, which exploded when it ruptured on Sept. 9, 2010, killing eight people in San Bruno. The similarities include that the pipeline is beneath densely populated or "high consequence areas," and may either be missing or have inconsistent pressure test documentation based on the type of pipe.
PG&E informed that they would provide updates on the progress as hydrostatic testing work proceeds.
For more information from PG&E, call 888-743-7431 or, in Spanish, 800-660-6789. For a video of what the testing entails, click here.