Bismarck, N.D. (AP) North Dakota health authorities say roughly 350 barrels of brine have spilled near Belfield. The North Dakota Department of Health said Thursday the saltwater spilled on Aug. 28 as a result of a tank leak at an oil and gas company's well site. The U.S. Forest Service has responded and Health Department officials were on their way Thursday. Brine is an unwanted byproduct of oil production that is many times saltier than seawater. It's considered an environmental hazard. Officials didn't indicate whether the spill has caused environmental damage. The Health Department says it will work on a remediation plan with the site's owner, Slawson Exploration Co.