Mark Heiderscheit, an environmental specialist with the Department of Natural  Resources, Washington office who responded to the scene, said the manure applicator filled his tank and left to apply the manure. The stirring device used to combine solid and liquid manure for application was left on and shifted when it was unattended spraying the manure out of the basin.

The manure runoff followed a channel designed to divert rainwater from the lagoon, through a field and settled over a tile buried beneath the snow. The tile outlet begins an unnamed tributary of Indian Creek.

Employees with NPKK Pork dammed the tributary on Dec. 15, and began pumping the water that they would knife in to the ground. Heiderscheit collected water samples from the tributary about 30 feet down from the tile outlet and found the ammonia levels at 0.8 milligrams per liter. Background level of ammonia in Iowa is 0.5 mg/l.

Heiderscheit continued to follow the tributary downstream where he found small dead fish. Vance Polton, fisheries technician for the Iowa DNR, was contacted to conduct a fish kill investigation.

Heiderscheit instructed to NPKK Pork to scrape solids from the area where manure flowed across the ground and evenly apply in on nearby fields. He said the DNR will review the case once all the field samples are in and the fish kill investigation is complete and will determine any future enforcement action at that time.