PG&E testing work to begin this week
For the past month, Pacific Gas and Electric Co. work crews have been preparing for hydrostatic pressure testing of a segment of what is known as line 132, one of two high-pressure gas pipelines that run through Stanford land for more than a mile. As part of the testing process, the utility company will vent gas from that pipeline segment so that it can be filled with water. That process will begin Tuesday, Oct. 11.
The work is part of the follow up to the San Bruno gas pipeline explosion of September 2010. California state regulators have required PG&E to perform hydrostatic pressure testing on all sections for which there is no prior documented testing. This includes most of the pipe that runs from Milpitas to San Francisco. Near Stanford, the pipe runs along Page Mill Road, Junipero Serra Boulevard, through a corner of the golf course and along Sand Hill Road to I-280.
This test involves pressurizing a section of pipe with water to a higher level than the pipe will operate with natural gas. In addition to validating the safe operating pressure for the pipeline, the test also can reveal weaknesses that could lead to defects and leaks.
PG&E is sending letters to campus PG&E customers alerting them to what they might expect during the venting process:
"On Tuesday, October 11, a pipeline near you will be carefully cleared of natural gas using a safe and common technique," the letter states. "You may smell gas during this process and at other points during testing work. This is safe and expected. While gas odors are likely, safety is our top priority, and we encourage any resident who has questions or concerns to call us 24 hours a day at 1-800-743-5000 or call 9-1-1 immediately.
"In addition to the natural gas odor, you may hear noise associated with testing activities and see PG&E field teams in your neighborhood. 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."
Related to the testing work, PG&E crews have been rebuilding the pipeline crossing at San Francisquito Creek near the intersection of Alpine Road and Junipero Serra Boulevard. Work is nearly complete; however, recent rains have interfered with its original scheduled completion date, and it will take another two weeks to finish and restore the area to its original condition.
Details on the PG&E testing program can be found at http://www.pge.com/myhome/edusafety/systemworks/gas/pipelinesafety/hydrostatictesting/index.shtml.