- A massive manure spill from Dale Humpal Dairy in Iowa led to the death of over 100,000 fish in a 10.2-mile stretch of Dry Run Creek.
- Investigators found lethal ammonia levels and evidence of manure runoff, linked to a faulty manure control structure.
- Dale Humpal Dairy has received federal subsidies despite a history of environmental violations in the region.
The Iowa Department of Natural Resources (DNR) traced the source of a catastrophic manure spill to Dale Humpal Dairy, a 330-head dairy operation in Winneshiek County.
The dairy industry in Iowa produces significant amounts of manure, and the state has a history of manure-related water pollution incidents. In 2017, a nearby operation owned by Darryl Humpal was also implicated in a manure spill that killed over 34,000 fish.
Environmental Catastrophe: Iowa Dairy Manure Spill Kills Thousands of Fish
The March 2025 manure spill in Winneshiek County, Iowa, is now one of the largest fish-kills in the state in the past decade. According to the Iowa DNR, over 100,000 fish perished as a result of manure runoff from Dale Humpal Dairy, a 330-head dairy operation. The spill affected a 10.2-mile stretch of Dry Run Creek, where investigators observed freshly dead fish and lethal ammonia levels.
A history of manure management violations has plagued the Humpal family’s operations. In 2017, a nearby feeding operation owned by Darryl Humpal was responsible for a spill that killed over 34,000 fish. Despite these incidents, both operations have collectively received approximately $4 million in federal subsidies, a controversial practice given their environmental records.
Manure management is a critical issue in Iowa, where industrial farming generates vast amounts of waste. Dairy cows alone produce around 150 pounds of manure daily, contributing to nutrient overloads that can devastate aquatic ecosystems. Livestock manure is also a major source of methane emissions, adding another layer of environmental concern.
The investigation into Dale Humpal Dairy revealed a previously noted defect in the farm’s manure control structure. Despite prior inspections identifying potential risks, corrective action was not taken, leading to the March 2025 spill. The Iowa DNR has yet to announce potential penalties or enforcement actions against the dairy.
The environmental impact of large-scale dairy operations in Iowa is increasingly under scrutiny, as incidents like the Humpal Dairy manure spill highlight the urgent need for stricter oversight and accountability.
“In Iowa, manure spills are commonplace: a recent report by Food and Water Watch found that from 2013 to 2023, there were 179 documented manure spills that killed almost 2 million fish.”
