Important Information About Your Drinking Water

Grinnell water has levels of radium, combined (226, 228) above drinking water standards

Recent water tests show that the Grinnell water system has radium levels higher than the standard set by drinking water regulations. Testing results we received on April 17, 2025 show that the system exceeds the standard, or maximum contaminant level (MCL) for radium, combined (226, 228). The standard for radium, combined is 5 pCi/L. The yearly average level of Radium, Combined over the last year was 6.45 pCi/L. While this is not an emergency, the City of Grinnell aims to inform the public about what this means, any necessary actions, and the steps being taken to address the issue.

Is the water safe?

Yes, Grinnell's water remains safe to drink, bathe in, and use for everyday activities. While the detected radium levels are slightly above the regulatory limit, they do not pose an immediate health risk. Radium must be ingested at much higher levels over a very long period of time to pose significant health risks to the average person. Individuals with specific health concerns should consult their doctor.

What is radium?

Radium is a naturally occurring radioactive metal that is found at very low levels in rocks and soil and may strongly attach to those materials. Everyone is exposed to small amounts of radium through air, water, and food. The EPA has set a notification requirement for a drinking water limit of 5 picocuries per liter (5pCi/L) for the combined levels of radium-226 and radium-228 to minimize potential health risks.

Treatment options

Certain types of home water softeners and reverse osmosis treatment units can be effective at removing radium from drinking water. Boiling water and carbon-based drinking water filters are not effective methods of removing radium.

What is being done?

Radium is naturally present in the water drawn from the Jordan Aquifer, which supplies Grinnell's water. The current water treatment plant does not have the capability to remove radium. To fix this, the City of Grinnell is building a new water treatment plant, which will have the necessary technology to reduce radium levels. The plant is expected to be operational by December 2026. In the meantime, the water department is using the best available wells to help manage radium levels, though current treatment options cannot fully lower them below the regulatory limit.

For more information

Contact: Keagan Richmond, Water Director, 702 Main St., 641-990-7521
Drinking Water Requirements-Radionuclides Rule, U.S. EPA
Radium Testing Results in Public Water, Iowa Health & Human Services
City of Grinnell Water Improvements Overview