The Iowa Department of Natural Resources has opened an investigation into a hog manure spill in Louisa County, the department announced on Friday.

According to the DNR, its Washington field office was notified by manure applicator business Catnip Ridge of a manure spill in a ditch near the intersection of Q Ave & 65th Street. The incident happened approximately 6.5 miles northeast of Winfield on Thursday. DNR staff responded to the location, finding that an originally unnoticed iron fencepost had torn a line, releasing an unknown amount of manure into the ditch, which then flowed into a nearby tributary. 

Once the tear was noticed, Catnip Ridge immediately ceased the flow of manure, clamped the line, and put dams into place.

The DNR added additional fresh water to the tributary. The evening of the incident, no dead fish were observed as cleaning efforts continued.

Revisiting the site Friday morning, the DNR found manure still moving through the tributary, observing a handful of dead fish, but a clog was preventing the manure from moving any further downstream. 

Cleanup efforts continue, and the incident remains under investigation.