FORT MADISON, Iowa – The Iowa Department of Natural Resources (DNR) is leading an investigation after a liquid fertilizer leak at the Merschman Fertilizer facility in Lee County reached a tributary that flows into the Mississippi River.

What happened

Plant staff discovered a leak in an on‑site containment tank in early October. The facility moved the UAN (urea ammonium nitrate) – a 32% nitrogen liquid fertilizer – to a backup tank located inside a secondary gravel and poly‑lined berm. Heavy rain over the past month prompted workers to use a sump pump to clear standing water. In doing so, an unknown amount of fertilizer mixed with rainwater was inadvertently pumped over the berm.

Path to the river

The mixture entered a drainage ditch south of the property. That ditch feeds an unnamed tributary that ultimately empties into the Mississippi River, raising concerns about water quality downstream.

Response and cleanup

DNR officials have deployed crews to contain the spill. Workers are pumping the remaining liquid into an alternate storage tank, and temporary dams have been installed at several points along the tributary to slow the flow of contaminated water.

Water samples have been collected for testing, and officials report that no dead fish have been observed so far. The agency continues to monitor the situation closely.

Public safety notice

Residents in the immediate area are asked to avoid the spill site and the surrounding drainage areas until the cleanup is complete. The DNR will provide updates as the investigation progresses.

Why it matters

The Mississippi River is a vital waterway for agriculture, commerce, and recreation throughout the Midwest. Any contamination, even temporary, can affect downstream ecosystems and water users. The swift response by state officials aims to limit any potential impact on the river’s health and the communities that rely on it.

Local authorities are working with the plant’s management to ensure that proper containment measures are restored and that future leaks are prevented. The incident underscores the importance of robust environmental safeguards for facilities handling high‑nitrogen fertilizers.

Original reporting: KWQC TV6 Davenport (local) — read the source article.