Pesticide pollution in Midwest and Great Plains rivers is getting worse, decade-long study reveals

Two researchers in wading pants and life vests stand next to river and hold thin metal pole used for taking water samples.
U.S. Geological Survey scientists take water samples from a South Dakota stream. Pesticides are meant to protect grains, fruits, vegetables and turfgrass from weeds, fungi and insect pests. But they don’t stay on farms and lawns, and a portion washes into creeks, streams and rivers. (USGS photo)

Mon, 07/13/2026

author

Celia Llopis-Jepsen

Debbie Baker, aquatic ecologist at the Kansas Biological Survey, is interviewed. Read the full story. 

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Excerpt:
 

U.S. farms use hundreds of millions of pounds of insect, weed and fungus killers each year and the runoff washes into waterways — especially in the middle of the country, where commodity crops are king.

A new study by the U.S. Geological Survey builds a clearer picture of pesticide pollution in streams. The scope of the study is notable, with scientists checking regularly for 80 chemicals across 81 sites for a decade.

At most of the sites, they found troubling levels of at least one pesticide between 2013 and 2022. The levels were high enough to possibly harm aquatic plants or invertebrates — creatures like mayflies and stoneflies.

And the data only provide a snapshot of the situation.

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Mon, 07/13/2026

author

Celia Llopis-Jepsen