The Iowa DNR has identified the source of a fish kill three miles southwest of Hampton.
The kill was reported July 15, along an estimated 1.5 miles of Maynes Creek.
The DNR traced the fish kill to a discharge of egg washwater from The Good Eggs operation. Investigators found high levels of ammonia in the stream near the S41 County Road Friday, west of Mallory Memorial County Park.
The egg washwater reached the stream when a tank at the facility overflowed into an underground drain tile. According to the DNR, the tile flowed into a ditch leading to the Maynes Creek tributary, known as drainage ditch 6.
The fish killed were mostly minnows and shiners, but included some smallmouth bass.
The DNR is still calculating the number of fish killed and plans to monitor the cleanup.