If you live in O'Fallon, you have probably seen the annual water quality report from your public water provider, or heard neighbors talk about one. Many of these reports list radium, a naturally occurring element that can appear in groundwater and in some source waters. Knowing what radium is, what the report actually says, and what you can check yourself will help you decide your next step without guessing.
What radium is
Radium is a radioactive element that forms naturally as uranium and thorium break down in rock and soil. It can move into groundwater, especially from deeper bedrock formations. Because it comes from the ground rather than being added to water, it is a question of source and treatment, not something a homeowner caused. This guide does not address health effects. If you have specific concerns about exposure, ask a licensed health professional or your local health department.
Reading the water report
Public water reports list contaminants that were detected, along with the level found and the regulatory limit. Look for the section on radioactive contaminants and note whether the results were within limits in the most recent sampling. The report also describes the source of your water, such as river water, groundwater, or a mix. Many homes in O'Fallon draw on more than one source, so the report may describe several. If anything is unclear, call the provider's customer line and ask what was sampled, where, and when.
If you are on city water
- Find the most recent report and check the radioactive contaminant section.
- Confirm whether your address is served by the source the report describes.
- Ask the provider whether sampling is scheduled again and whether any changes to the source are planned.
- Keep a copy of the report with your home records so you can compare future years.
If you have a private well
Deep bedrock wells in the wider St. Charles County area can carry naturally occurring radium, gross alpha, and uranium. A basic home test kit for hardness or iron will not tell you whether radium is present. Radium requires laboratory analysis. Use a certified or accredited laboratory, and ask the lab which containers, preservatives, and shipping steps it requires before you collect the sample. If you also want to check for coliform bacteria or E. coli, the state public health laboratory offers free or low-cost testing for those, but radium testing usually goes through a certified commercial lab, so confirm what is offered before you send anything.
Collect the sample from a cold tap that is not connected to a softener or filter, because treatment equipment can change the result. Follow the lab's instructions closely, label the container, and deliver it promptly. Keep the lab report with your well records.
Where a softener fits
A water softener is built to reduce hardness minerals, which are a different concern from radium. Do not assume a softener removes radium unless the equipment is specifically certified for that purpose and the product documentation says so. Ask for that documentation before you buy or rely on it, and keep it with your system records. If a softener is already installed, check its bypass setting before sampling so you know what the test represents.
Next steps
- Read your most recent public water report or well lab results.
- Confirm your source and whether it may be deep bedrock.
- If you are on a private well and have not tested for radium, arrange a certified lab test.
- If results show radium, ask a qualified water treatment professional which options are certified for your situation, and ask for documentation.
- Retest on the schedule the lab or provider recommends.