DENISON, Iowa (KCAU) — Process wastewater has flown into the Boyer River in Denison, officials alerted.

The Iowa Department of Natural Resources (DNR) said in a release that Smithfield Food was alerted by alarms Sunday around 2:45 p.m. of a malfunctioning wastewater processer. Staff then closed a nearby storm drain, but officials believe 50 to 100 gallons of wastewater had already gone through the storm drain and into the Boyer River.

Smithfield is working to clean the wastewater. The DNR is monitoring the cleanup and will consider any appropriate enforcement action.

Until the cleanup is complete, the DNR is asking people to avoid recreation in the area.