LOS ANGELES (Reuters) – A Los Angeles-area natural gas plant has leaked planet-warming methane gas for years but work to fix the problem tracked by NASA has been delayed until November, a city power official said.

Faulty natural gas compressors at the 690-megawatt Valley Generating Station have been leaking more than 10,000 cubic feet of methane per hour “for the last couple years,” Norm Cahill, the Los Angeles Department of Water and Power’s (LADWP) director of power supply operations, told the utility’s board of commissioners on Tuesday.

Video of the meeting was posted online on Wednesday.

A leak of that magnitude, over the course of a year, is roughly equivalent to the emissions of 30,000 cars, according to environmental group Sierra Club.

In a statement, LADWP said the level was low in comparison to other emissions sources and dwarfed by the 2015 leak at the Aliso Canyon natural gas storage facility that lasted four months and forced evacuations of a suburban neighborhood.

“Though the methane emissions are considered low, we are very sensitive to the concerns of local residents,” the utility said in a statement, saying it was expanding monitoring at the facility.

There is mounting evidence that accidental releases of natural gas from energy infrastructure are a significant contributor to global climate change. Methane, while colorless and odorless, is 80 times more potent than carbon dioxide during its first 20 years in the atmosphere.

The leak was reported to the utility on Friday by NASA’s Jet Propulsion Laboratory, an arm of the U.S. space agency that uses airborne sensors to observe methane sources.

The utility had been made aware of the extent of leak in March, following a study by power industry research group the Electric Power Research Institute.

The utility delayed repairs due to the challenges of taking a large plant offline during the summer months when demand is high, it said. New equipment is scheduled to be installed in November.

The Valley power plant generally only runs when needed to supplement other resources, and the utility said it will minimize usage of the plant as much as possible.