BISMARCK, N.D. (AP) — North Dakota officials say more than 20,000 gallons of saltwater was released when a hole was discovered in a pipeline during installation.

The incident happened at a Little Rock Resources well located about 11 miles west of Kenmare, in Ward County. Officials say all but about 200 gallons were recovered.

Saltwater is an unwanted byproduct of oil production and is considered an environmental hazard by the state.

A state inspector has been sent to the site and will monitor additional cleanup.