The North Dakota Department of Health announced an oil spill in the western part of the state, at the least third release so far this month.

The state agency said Oasis Petroleum reported that 490 barrels of oil and 455 barrels of brine, a liquid associated with production, were released as a result of a tank overflow. Nearly all of the released material has been recovered as of the Wednesday announcement.

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

The release was reported in western Williams County, near the heart of the shale oil basins in North Dakota. Oasis holds roughly 500,000 net acres in the Bakken and Three Forks reserve areas, which combine for nearly all of the oil produced in the state.

There was no statement from the company on the release. The North Dakota Health Department gave no indication that public was endangered.

Summit Midstream last week confirmed a release from a four-inch pipeline near the same area as the Oasis release. Around 70,000 barrels of produced water were released.

A division of Hess Corp. last week spilled more than 2,000 barrels of water used during oil production at a site southwest of Tioga.

The water was used during a process known as enhanced oil recovery, a technique that involves flow stimulation from steam, gas or chemical injections into the well.

State data from November show 1.18 million barrels per day worth of oil production, a new all-time high.