There will be 36 nitrate-related drinking water violations in Iowa in 2025, more than double the number reported in 2024, according to a report from the Iowa Department of Natural Resources.
Each year, the DNR submits a compliance report to the U.S. Environmental Protection Agency detailing violations of federal drinking water standards, from excessive contamination levels to operator certification requirements.
Nitrate contamination levels above EPA limits were the most common health-based standard violated by public water systems, according to the 2025 report. The report said the 36 breaches occurred across 13 systems, impacting a total of 2,479 customers. Nitrate violations accounted for 41% of the 87 total violations of health-based standards.
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Health-based standards assess whether a public water system produces finished water within limits for drinking water contaminants established by the EPA.
2024 report revealed that there were 14 nitrate contamination level violations across nine public water systems, impacting 1,765 customers. This was also the most common violation in 2024, accounting for nearly 19% of the 74 total violations.
in 2023In Iowa, seven public water systems had 38 nitrate contaminant violations. The DNR’s graph of nitrate violations from 2016 to 2025 shows significantly more nitrate violations in 2023 and 2025 compared to other years.
Just over 90% of Iowa’s systems draw their water from groundwater sources. Surface water sources, such as rivers, and impacted groundwater sources, such as shallow wells near rivers, make up the remaining 10% of the system, which supports approximately 47% of the state’s population.
iowa river usually During spring and summer, nitrate levels rise as heavy rains wash nutrients away from the land and into rivers. Nitrates and nitrites can enter source waters through natural decay of organic matter, commercial fertilizers, and contamination from human waste and livestock waste, the DNR report said.
Nitrate levels in major rivers, including the Des Moines and Raccoon Rivers, reached near-record high levels in the summer of 2025, leading to the first lawn watering ban in the Des Moines metropolitan area. Levels left expensive During the winter, the Central Iowa Water District run Nitrate removal facility will be shut down for a limited time in January and another facility will be issued. No lawn watering allowed For a short period this summer.
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Ingesting water with nitrate concentrations above the EPA limit of 10 milligrams per liter can be fatal for infants under 6 months of age because the contaminants can affect the oxygen-carrying capacity of the infant’s blood and cause a disease known as methemoglobinemia, or blue baby syndrome.
Some studies also point to negative health effects from consuming nitrates at levels below EPA limits. Some Iowans Nitrate levels in the state are believed to contribute to the state’s high cancer rates.
Nitrate levels in finished drinking water that exceed EPA standards are considered serious violations, meaning they pose an “immediate” health risk, according to the DNR report. A violation occurs when the system records a level above the maximum during a monthly, quarterly, or annual compliance period. Compliance is achieved when the system records two consecutive quarters in which all samples are within specified limits.
More than half of the nitrate violations in 2025 occurred in four public water systems, according to the report. The report states several things Systems with nitrate violations have treatment systems installed or connected to other systems to address the nitrate violation problem.
Little Brown Church in Chickasaw County had nine nitrate violations in 2025, Lazy T Campground in Delaware County had four nitrate violations and Lost Beach Resort, also in Delaware County, had four nitrate violations. Sac County’s early municipal water system, classified as a community water system, had four nitrate violations during the year.
Other than the early municipal water systems, the systems with the most violations were classified as temporary non-public water systems. It is a type of public water system that serves more than 25 people every day and at least 60 days a year.
The report also found “significant” reporting and monitoring violations by the public water system. A violation occurs when a system fails to collect, report, analyze, or follow proper sampling guidelines for a particular contaminant within a compliance period that varies by contaminant.
The report found that about 20% of Iowa’s public water systems had serious reporting and monitoring violations. The majority of reporting and monitoring violations were failures to collect coliform samples. In Iowa, there were 249 violations related to coliform monitoring in 158 systems.
Nitrate monitoring was one of the pollutants with the highest number of reported violations in 2025, with 66 systems reporting a total of 84 violations.
Reporting and monitoring violations can, in most cases, be remedied by performing the necessary monitoring or issuing the necessary public notice. Administrative orders may be issued for systems that do not comply in a timely manner.
Approximately 95% of Iowa’s population, or more than 3.12 million people, use public water systems, with the remainder receiving water from private water facilities such as on-site wells.
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