(Crawford County, Iowa) – The Iowa Department of Natural Resources is investigating a wastewater bypass at the City of Denison in Crawford County. Officials at the Iowa DNR Field Office in Atlantic received a call today (Monday) from Denison Municipal Utilities (DMU) regarding a wastewater bypass due to a lateral service line that had become plugged.

The discharge was discovered around 7:40 a.m. at the Denison Country Store located at 1108 4th Avenue S. in Denison. It is estimated that up to 300 gallons of sewage flowed onto the ground and a portion of it flowed into a storm sewer which outlets to the Boyer River.  DMU staff were able to remove the blockage and officials say the discharge has stopped.

Cleanup efforts have begun. Residents are advised to avoid the area. Water samples have been collected for testing. No dead fish have been observed at this time. The Iowa DNR will follow up with the city for further assessment.

To report a release after hours, please call the DNR’s emergency spill line at (515) 725-8694. Quick reporting can help DNR staff identify the cause of an incident. The DNR website has more information about spill reporting requirements.