Waterways were soiled by the spill of an unknown amount of material used to produce oil and gas in a North Dakota county, the state government said.

The North Dakota Department of Health said about 1,000 barrels of brine were spilled from a corroded pipeline at a well site owned by energy company Oasis in McKenzie Country.

Energy companies inject brine, or salt water, to improve oil and gas production from shale deposits.

"Much of the produced water brine was contained and recovered on the pad, but an unknown amount spilled over onto adjacent land and impacted a nearby stream," the Health Department said in a Thursday announcement.

The Environmental Protection Agency said brine may contain toxic metals and radioactive substances that can be "very damaging" to the environment and public health if released on the surface.

North Dakota lies at the heart of the shale boom in the United States. Oil production in July, the last full month for which data are available, was 1.1 million barrels per day on average, a state record.

There was no comment from Oasis on the release.