The state Department of Natural Resources is wrapping up its investigations of three fishkills this week.

The fishkill in Buena Vista County was reported Monday and has been traced to a truck wash.DNR officials say Binder Livestock Trailer Washout of Sioux Rapids had sprayed industrial wastewater on fields near Rembrandt, legally, but then it seeped into tile lines and into a tributary of the Raccoon River.

The wastewater turned the stream red and killed more than 700 fish. The truck wash may face restitution.

Two other incidents in northwest Iowa are being blamed on natural causes — low water levels and high water temperatures. One fishkill was along the Ocheyedan River in Osceola County, the other was off Ingham Lake in Emmet County.