New Jersey’s largest utility has been repairing methane gas leaks in its natural gas pipeline system more quickly and efficiently, thanks to an unlikely partnership.

Last year, Public Service Electric & Gas teamed up with the Environmental Defense Fund and Google to work on its $905 million gas infrastructure replacement program.

A specially equipped Google Street View mapping car equipped with methane gas sensors drove across PSE&G’s service area where gas main replacements are planned, and constant readings were taken of methane gas leak locations and volume.

“We used that to prioritize which pipes we will replace first, and therefore have a greater impact on reducing methane emissions and the environment,” PSE&G spokeswoman Karen Johnson said.

Methane is a powerful greenhouse gas that contributes to global warming, so it poses an environmental concern.

Virginia Palacios, a senior research analyst with the Environmental Defense Fund, said after PSE&G used this methodology to prioritize their pipeline replacement program, “they were able to reduce 83 percent of the measured leak flow rate by replacing one third fewer pipes than they would have normally.”

She said the EDF methane mapping project, with Google and Colorado State University, began back in 2014, when methane sensors were attached on top of a Google mapping car as it drove down the street.

The data that was collected every half second was then run through a computer program to weed out false positives. A map of methane gas leaks was then produced.

“It’s not just about where the leaks are, it’s about how big the leaks are," Palacios said. "We can see how fast gas is escaping out of any given leak, which is something we haven’t been able to do before. This technology is good for the utility, its customers and the planet.”

Johnson explained a lot of cast iron pipes were installed in the early 1900s as New Jersey’s cities were developing, and while PSE&G stopped using cast iron in the 1950s and began phasing in steel and more durable plastic pipes, many cast iron mains remain underground.

“They are constantly being replaced, so the partnership with Google and EDF was a perfect fit,” she said.

You can contact reporter David Matthau at