Pesticide Spill Leads To Fish Kill In Lee County Iowa

The Iowa Department of Natural Resources is investigating a fish kill in Lee County near the small town of Houghton after what appears to have been an accidental chemical spill.

How Did It Happen?

On June 25, a chemical mixture called pesticide rinsate was accidentally spilled near the ChemGro cooperative.

"Pesticide rinsate" is basically the leftover water used to wash out pesticide tanks or spraying equipment. It's not pure pesticide, but it still contains chemicals that can be harmful. In this case, it also contained an ammonia-based cleaning product.

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Where Did The Chemicals Go?

Instead of staying on the ground, the contaminated water ran into a storm drain, flowed into a nearby creek, and continued downstream into larger streams.

When DNR workers arrived, they noticed the creek water had turned white and it had a strong ammonia smell.

What Happened To The Fish?

I hate to break it to you... But the fishies are gone.

When DNR staff returned the next day, they found dead fish for about 3 miles downstream from where the spill happened. Most of the dead fish were small minnows and bullheads.

Tests showed the creek had high levels of ammonia.

Ammonia is toxic to fish. It damages their gills, making it difficult or impossible for them to breathe underwater. Even if people can safely smell ammonia from the creek, fish are much more sensitive to it.

What Is Happening Now?

The DNR has collected water samples to test for ammonia, pesticides, herbicides, and other pollutants. They have asked the co-op to flush and pump contaminated water out of the drainage area and have also started an investigation to determine exactly what happened and whether anyone violated environmental laws. If they find violations, enforcement action could follow.