The City of Storm Lake has released its annual Drinking Water Quality Report for 2025, and once again, the city’s water system recorded no violations.
The report details where Storm Lake’s drinking water comes from, how it’s treated, and the results of extensive testing for regulated contaminants. The city draws from three groundwater sources—the Buried Sand and Gravel aquifer, the Cambrian-Ordovician aquifer, and the Dakota aquifer. State assessments show the Buried Sand and Gravel aquifer is more vulnerable to surface contamination, while the other two aquifers have natural layers that offer stronger protection.
Testing throughout 2025 showed Storm Lake’s water met all federal and state standards. Levels for regulated contaminants—including nitrate, chlorine, fluoride, lead, and copper—all came in well below allowable limits. Lead samples showed a 90th‑percentile result of zero parts per billion. And the city’s manganese reading was 7 parts per billion, far under the federal health advisory level of 300 ppb for infants.
The city also participates in the U.S. Environmental Protection Agency’s nationwide Unregulated Contaminant Monitoring Rule. As part of that study, lithium was detected between 110 and 130 parts per billion. Lithium isn’t regulated, but systems are required to report it when found.City officials say they remain committed to improving treatment processes and protecting local water resources. The full 2025 Drinking Water Quality Report is available on the city’s website at stormlake.org/287/Drinking-Water-Quality-Report.
