WILLISTON – A failed seal on a water heater unit caused the release of 30 gallons of hydraulic oil at a site 7 miles northeast of Williston on Sunday. The spill occurred while Zavanna, LLC was pumping water from the Little Muddy River to use for enhanced oil recovery.

The North Dakota Department of Environmental Quality (NDDEQ) was notified of the spill on Tuesday.

Zavanna estimates about 10 gallons were recovered. The remainder of the oil dispersed on the ice of the Little Muddy River, with an estimated 5 gallons released into the river.

Personnel from the NDDEQ have inspected the site and will continue to monitor the investigation and remediation.