BOWMAN COUNTY — A pipeline leak in Bowman County spilled an estimated 420 gallons of source water, impacting a creek.

Source water is used for enhanced oil recovery. It is higher in dissolved solids and minerals than fresh water, but much lower in salt than produced water, which is a mixture of saltwater and oil that can contain drilling chemicals.

The leak on the pipeline operated by Denbury Onshore LLC occurred about 10 miles south of Marmarth on Wednesday, Oct. 23, and was reported the same day, according to the North Dakota Department of Environmental Quality. The cause of the leak wasn't immediately determined.

Initial estimates indicate about 10 barrels of source water spilled, impacting Hay Creek. The creek discharges into the Little Missouri River about 2 miles downstream of the release point. No impacts were immediately detected in the river.

State officials are inspecting the site and will continue to monitor the investigation and remediation.