BISMARCK — About 200 barrels of produced water leaked from a pipeline onto a pasture in McKenzie County Friday, Aug. 30, the North Dakota Department of Environmental Quality said Tuesday.

The leak occurred about 4 miles west of Watford City. The pipeline is operated by Henry Hill Oil Services.

Produced water is a byproduct of oil and gas development.

It's unclear what caused the leak, which would amount to roughly 8,400 gallons, the DEQ said in a news release. Agency personnel are inspecting the site and will continue to monitor the investigation and remediation.

State officials were not yet aware of any water sources that were affected by the spill.