What’s Wrong with Iowa’s Water?

Iowa is the only state bounded on either side by major rivers and has long been one of the country’s most agriculturally productive states. Iowa produces the most corn, pigs, eggs, ethanol, and biodiesel in the country and ranks second in soybean and oat production. In 2024, more than half of Iowa’s rivers and streams were designated as impaired. According to the Iowa Department of Natural Resources, a waterbody is impaired when the water quality can no longer support its designated uses for “human contact, aquatic life, fish consumption, or drinking water.” 

In June of 2026, Central Iowa Water Works issued their second-ever ban on watering lawns in an effort to protect the region’s drinking water supply from “elevated nitrate concentrations.” Nitrates are compounds of nitrogen and oxygen naturally found in air, soil, water, and some food. They are used in fertilizers, food preservation, pharmaceutical medications, and even explosives. A 2018 report found correlation between increased nitrate levels in drinking water and increased risk of certain cancers, thyroid disease, neural tube defects, and birth defects.

Concentrated Animal Feeding Operations (CAFOs or factory farms) are large-scale agricultural facilities that house confined livestock, meaning animals are maintained indoors for 45 days or more in a year. Northwest Iowa is home to a number of CAFOs, which produce huge amounts of waste that directly impacts Iowans. Iowa’s factory farms produce 300 million pounds of manure each day. Manure waste contains high concentrations of nitrogen, and is often dumped untreated into the environment. Rainfall and snowmelt wash excess nitrogen into streams and rivers, and nitrates enter groundwater and agricultural drainage tiles that discharge into waterways. Extreme weather events exacerbate water pollution; in the summer of 2024, major flooding in the Midwest led to the overflow of several manure lagoons. 

In 2023, the Polk County Board of Supervisors commissioned the Central Iowa Source Water Resource Assessment (CISWRA). The report found that, in many cases, nitrate levels exceeded federal standards of 10 mg/L, as set by the Environmental Protection Agency (EPA). The Des Moines and Raccoon Rivers are primary sources of drinking water for nearly 600,000 people in Iowa. However, after the CISWRA report was completed, public officials “zeroed out” the remaining funds intended for public education work on the report’s findings, which raised public concerns over the relationship between Big Agriculture and public officials. Big Agriculture refers to the network of agribusiness corporations, industrial livestock operations, and agricultural associations that have significant influence over agricultural production and environmental policy.

Iowa’s industrial farm pollution flows downstream, with runoff and overflow contaminating both water and land throughout the Mississippi River Basin and into the Gulf of Mexico. The Gulf of Mexico Dead Zone is an “algae-choked area created by high nitrate and phosphorus concentrations pouring into the Gulf from the Mississippi and Atchafalaya Rivers.” A Dead Zone indicates an area that is uninhabitable to fish and marine life, which negatively impacts Gulf state economies. Iowa contributes the most agricultural nutrient runoff to the Gulf than any other state along the Mississippi river.  

Iowa is also experiencing a climbing rate of new cancer diagnoses. Research has linked ingesting nitrates to cancers, even at levels under federal limits. The threat of elevated nitrates in drinking water particularly impacts low-income communities, the elderly, children, and communities of color in Iowa, which have higher exposure rates than the state average. Recent polls found that almost 75% of Iowans say that the rising cancer rate is a top concern and about 60% say “water quality and water pollution” are also serious matters.

Voluntary Incentive-Based State Measures 

Iowa has largely relied on voluntary conservation measures to regulate waterways, with agricultural organizations such as the Iowa Farm Bureau supporting voluntary regulation over mandatory regulation, citing that additional regulation would burden farmers and rural communities. Below are recent state policies that are either voluntary or reduce regulations on agricultural practices: 

Proposed Regulatory Alternatives 

Many Iowans and environmental advocates believe that mandatory regulations are necessary, given the worsening water pollution and rising cancer rates. Below are recent examples of proposed bills and legal actions aimed to address the water crisis: