Fertilizer Spill into Tributary of the Maumee River in Northwest Ohio Kills Estimated 20,000 Fish

 

      In early July it was observed that parts of the Maumee River in Henry County, Ohio were turning a reddish color.  The Ohio Department of Natural Resources put out a statement on July 13 that 11 miles of the river were affected, with an estimated 18,000 to 20,000 fish killed. The fish range from 3-inch sunfish to carp over three feet long. It was found that a spill of liquid fertilizer was the cause.  28% Urea Ammonium Nitrate (UAN) liquid fertilizer spilled into Huston Creek and then flowed into the Maumee River.

     Tests of the river water for ammonia in the town of Napoleon showed that it was at a level still safe for humans. However, as a precaution, the town is not drawing water from the river temporarily.

“The Ohio Environmental Protection Agency issued violations to Triway Nitrogen and Farmers Elevator Associates for the fertilizer spill and required the businesses to assist with cleanup actions and take steps to prevent future contamination, WTVG reported. Both are located near the Huston Creek, which flows into the Maumee River.”

     The fish were killed by oxygen depletion when ammonia from the fertilizer reacted in the water, consuming dissolved oxygen and basically suffocating the fish.

     The highest amounts of ammonia recorded in the Maumee River were 2.8 ppm, far below the 50 ppm considered the threshold for human harm.

     The Ohio EPA is leading the cleanup efforts. Heavy rainfall has helped to dilute the spill and reduce further threats to aquatic wildlife. The river water is considered safe for human recreation.    

     Acting Napoleon City Manager Chad Lulfs said the city was notified Saturday after the fertilizer reached the river.

"It inundated the creek and the earthen dams that were present, washed out, and it was released into the river," Lulfs said. "Saturday, I was notified by our fire chief of the incident and that we had a large number of fish that had been killed in the river."

"We took random grab samples. We tested those samples. The threshold that can be an irritant to human skin, an irritant to eyes, is 50 parts per million," Lulfs said. "Of all the samples we took, the highest test we got was 2.8 parts per million, so it didn't represent an issue for those out on the river for recreational purposes."

"The Ohio EPA says the environmental contractor has since reinstalled containment points and restarted aeration in the creek to capture any remaining fertilizer. The agency says cleanup efforts are continuing, while the heavy rainfall also helped dilute the ammonia in the water, significantly reducing its concentration.

    

 

References:

 

Fertilizer spill kills up to 20,000 fish in Maumee River, reports say. Bailey Gallion, Columbus Dispatch. July 15, 2026. Fertilizer spill kills up to 20,000 fish in Maumee River, reports say

Ohio officials: Up to 20,000 fish killed after fertilizer spill reaches Maumee River: The city of Napoleon says drinking water remains safe as cleanup continues with no timeline for completion. Anthony DiFilippo. WTOL11. July 13, 2026. Ohio officials: Up to 20,000 fish killed after fertilizer spill reaches Maumee River | wtol.com