WILLEY, Iowa (KCAU) — Iowa officials are investigating manure from a feedlot running off into a tributary south of Carroll, Iowa.

The Iowa Department of Natural Resources (DNR) stated in a release that it received an anonymous tip Thursday night telling them that manure was being discharged from Wendl Feedlot about six miles south of Carroll.

The feedlot owner, Brian Wendl, was notified of the incident and left his vacation to oversee the containment and cleaning of the runoff, the release states.

Friday morning, DNR staff found runoff going from a saturated field and flowing into a tributary of Willey Creek before then entering the Middle Raccoon.

Officials found elevated ammonia levels in the tributary at the field. About a mile downstream though, they found “considerably lower levels,” the release states, and there were no signs of dead fish. The release adds that the stream was running high after rain over the last few days.

The discharge happened after the field became saturated from “an attempt to dewater a basin” that held manure.

To stop runoff, Wendl is working to construct a berm along the stream. DNR staff will monitor the cleanup and containment as well as sending water samples to a laboratory for testing. The DNR said it is considering appropriate enforcement.