The breach occurred on a Sunoco Logistics Partners LP pipeline in the area of Gamble Township, around 100 miles (160 kms) north of Harrisburg, according to state authorities, who estimated the spill at about 1,300 barrels (55,000 gallons).

The gasoline leaked into Wallis Run, a tributary of the Loyalsock Creek as a result of floods and landslides during heavy rainfall on Thursday night, the Pennsylvania Department of Environmental Protection (DEP) said in a statement. The Loyalsock Creek runs into the West Branch Susquehanna River around 15 miles (24 kms) south of where where the spill occurred.

“Crews will use skimmers to remove gasoline from the top of affected waterways and will erect containment booms downstream,” Sunoco Logistics said in a statement, without specifying which waterways had been affected.

Pennsylvania environmental officials said that since rain is predicted to continue, it could be later on Friday night or Saturday before the water recedes and the break area on the pipeline can be found.

Pipelines: The Worst Way to Move Oil, Except For All the Rest

A drop in pressure on the eight-inch pipeline was detected by the Sunoco Logistics Control Center shortly after 3 a.m. on Friday. The pipeline was shut down and emergency response personnel dispatched to the scene, Sunoco Logistics said.

Pennsylvania American Water said in a Facebook post it would notify customers when its water conservation notice is lifted.

The spill came as the Standing Rock Sioux tribe and environmental activists protest against construction of a 1,100-mile (1,886-km) North Dakota oil pipeline Sunoco will operate, saying it threatens water supply and sacred sites.

Sunoco Logistics spills crude more often than any of its competitors with more than 200 leaks since 2010, according to a Reuters analysis of government data.

The U.S. Environmental Protection Agency did not immediately respond to a request for comment.