PG&E will conduct pressure-testing in the next two months on its gas transmission line running through Palo Alto, the utility announced.
The work will begin in "a week or two" and last until mid-September, officials said.
The testing will not disrupt service but may cause a "temporary gas odor" and will be visible above ground, with traffic cones and detours, testing equipment and machinery, including excavators and water tanks.
"While gas odors are likely from the work being done..., safety is our top priority and we encourage any resident who has questions or concerns about the smell of gas to call us 24 hours a day at 1-800-743-5000, or call 911 immediately," PG&E said.
The transmission line, Line 132, enters Palo Alto from the north along Junipero Serra Boulevard, turns left at Page Mill Road, right on Alma Street, left on El Carmelo Avenue, right on Waverley Street, left on Loma Verde Avenue, right on Cowper Street, left on Ashton Avenue, and right on Middlefield Road, continuing south into Mountain View.
A major access point for the testing will be on Alma, just south of Colorado Avenue, a PG&E official said.
According to a letter PG&E sent Friday to property owners near the pipeline, the project will involve hydrostatic testing, sending water through the pipeline at a much greater pressure than it would ever operate with natural gas.
PG&E officials said the test will "validate a safe operating pressure for the pipeline and can also reveal weaknesses that could lead to defects and leaks." They said the "situation is safe" and that the pipeline will be "cleared of gas utilizing a safe and common technique."
"If the pipe section does not meet acceptable standards during the test, it will be replaced with new pipe that has already passed a pressure test," PG&E's letter stated.
PG&E has faced heavy scrutiny over the safety of its pipelines since Sept. 9, 2010, when a gas explosion in San Bruno killed seven people and destroyed 37 homes. A portion of Line 132 ran next to the explosion site.
The Palo Alto work is part of PG&E's planned testing or replacement of some 150 miles of pipeline segments that are similar to the San Bruno segment.
"Hydrostatic testing is expected to become an important part of our overall pipeline maintenance practice moving forward," the agency said.
For information on the exact location of pipelines, visit www.pge.com/pipelinelocations or call 1-888-743-7431.