(Bloomberg) -- A leak at a Pennsylvania natural gas facility that lasted 11 days released over 1 billion cubic feet of the fuel into the atmosphere, according to its owner.

The leak at the Rager Mountain Storage facility in Jackson Township was finally halted Thursday, Equitrans Midstream Corp. said. The company said a crew successfully flooded the storage well that was emitting gas through a 1 5/8-inch vent.Equitrans’s preliminary and conservative estimate is that 100 million cubic feet of gas a day was released. That equates to a total of 15,800 to 20,300 metric tons of methane, according to BloombergNEF. The largest known methane release in the US occurred in 2015, where an estimated 97,100 tons was emitted over several months from a storage facility operated by a unit of Sempra Energy at Aliso Canyon, Los Angeles.

The Pennsylvania leak underscores the risk posed by natural gas, which fossil fuel companies have long promoted as an energy source that can help nations transition away from coal. Natural gas burns cleaner than coal, but that advantage is erased if too much of it leaks directly into the atmosphere where it has 84 times the warming potency of CO2.

Methane is the primary component of natural gas. Since the industrial revolution it has accounted for about 30% of the increase in global temperatures. Halting intentional releases and accidental leaks of the potent greenhouse gas from fossil fuel operations is viewed by scientists as some of the lowest hanging fruit in the fight against climate change. Equitrans said in a statement that it was first notified of the incident at Rager Mountain on Nov. 6. Technicians who arrived at the site as part of its emergency response observed gas seeping from the vent, “which was working as designed to relieve pressure from the casing.’’

A Pennsylvania Department of Environmental Protection representative said in an email that the venting is a violation of state environmental laws, but that it would be premature to speculate on any enforcement action or civil penalty during an ongoing incident and investigation.


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