BISMARCK, N.D. (AP) — North Dakota’s Health Department says more than 10,000 gallons of oil has spilled from a pipeline in Williams County.

The agency says in a statement that the spill was reported Friday by Samson Oil & Gas USA Inc.

Environmental scientist Brian O’Gorman says the spill occurred Thursday north of Williston at a well pad and affected a small patch of nearby grassland.

O’Gorman says the cause of the spill is under investigation. He says no water sources were affected.

O’Gorman says about 4,200 gallons had been recovered by late Friday afternoon and the spill was contained.