Energy pipeline operator Energy Transfer LP has disclosed a pipeline rupture in Louisiana last month that released 8.2 MMcf of natural gas, according to a report filed with the U.S. National Response Center.

The July 22 leak, the equivalent of enough gas to supply 40,000 U.S. homes for a day, originated from a gathering system near Ringgold, Louisiana, the report said. The line has been shut until further notice.

The cause of the rupture is under investigation, and a sample section of the pipeline has been sent to a lab for examination, said Louisiana Department of Natural Resources spokesman Patrick Courreges.

Natural gas is mostly methane, a powerful greenhouse gas.

The company has 30 days to provide Louisiana with a report on the cause of the leak, after which the department will conduct its own review.

Energy Transfer, founded by billionaire Kelcy Warren, was not immediately available for comment. It has suffered a string of leaks and safety incidents this year.

Last month, a burst natural gas pipeline, owned and operated by the company, caused a roughly two-hour blaze in a rural area outside of Houston.

In June, a spill from Energy Transfer’s Mid-Valley pipeline released more than 200,000 gallons of crude oil into rural Tennessee in what was among the biggest leaks of its kind in the state’s history.

Earlier this year, Energy Transfer contractors were injured after a 10-inch natural gas gathering line ruptured on the Barksdale Air Force Base in Louisiana in April.

Energy Transfer also this year was charged with environmental crimes in Pennsylvania after a portion of its Revolution gas pipeline failed after a 2018 landslide. A fire resulting from the blast destroyed a nearby home, damaged power lines and burned several acres of surrounding woodland.