PG&E began testing line 132 – one of two mile-long gas pipelines running underneath Stanford property – on Tuesday, according to a University statement. During the test, PG&E will vent all gas from the pipeline segment and fill it up with water at a specified pressure higher than what the pipe normally accommodates. Any sections of the pipe that do not meet acceptable safety standards during these test conditions will be replaced with new pipe that has already passed a pressure test, according to the PG&E website.

Line 132 runs from Milpitas to San Francisco and crosses Stanford property when it follows Page Mill Road, Junipero Serra Boulevard, a corner of the golf course and Sand Hill Road to reach I-280. Stanford PG&E customers who might be affected by the test were sent a letter by the utilities company.

“You may smell gas during this process and at other points during testing work,” the letter stated. “This is safe and expected.”

“In addition to the natural gas odor, you may hear noise associated with testing activities and see PG&E field teams in your neighborhood,” the letter said. “Our crew may use traffic safety cones and/or detour signs, testing equipment such as above-ground pipes and valves or machinery such as excavators or water tanks.”

California state regulators required PG&E to perform this pressure testing on all sections of pipeline that have no documented test results following the 2010 San Bruno gas pipeline explosion that resulted in 38 destroyed homes and eight deaths. According to investigators, the incident resulted from an electrical glitch in a Milpitas gas-line terminal that raised the line’s gas pressure.

PG&E is also working on rebuilding a pipeline crossing at San Francisquito Creek. Recent rains have delayed the scheduled completion date by two weeks.

– Kurt Chirbas