PG&E to survey 1.2 million customer service lines using methane leak detection technology

For this year’s gas distribution safety survey, PG&E workers will evaluate 1.2 million customer service lines, gas meters, and distribution pipelines, utilizing vehicle-mounted and hand-held methane leak detection technology in the process.

“Over the course of this year, our crews will cover thousands of miles as they carefully survey the system,” Joe Forline, PG&E Gas Operations senior vice president, said. “They will be equipped with technologies that are so precise, we are able to detect even the smallest molecule of methane. This proactive assessment is part of our comprehensive commitment to operate a safe, reliable, and environmentally focused system that provides customers with natural gas 365 days a year.”

In all, the lines to be surveyed span approximately 42,000 miles. PG&E crews evaluate them every three years. These lines feed service lines that connect directly to natural gas meters. PG&E also surveys its entire high-pressure transmission pipeline system twice per year. Survey crews attend to the lines on-foot or in vehicle patrols.

Mobile crews use the Picarro Surveyor system, a vehicle-mounted leak detection technology to measure methane plumes in the air, map their location and prioritize leaks by their grade – as denoted by national scale – within PG&E’s system. Vehicles roll through neighborhoods for this, measuring air and methane in parts per billion, which allows the sensors to lock down the exact location of leaks. These tend to take place at night or in the early hours of the morning.

Foot patrols are the more traditional method, and for these, personnel and contractors of PG&E rely on hand-held methane detection devices. The company notes it issued new devices this year, which will work for both service lines and customer meters. These patrols follow more regular work hours, between 6 a.m. and 4 p.m.

In either case, if leaks are detected, they are graded and repaired according to their severity. Those of the highest caliber – grade one – will be repaired immediately.