If your O'Fallon home draws water from a deep bedrock well, radium and gross alpha are worth a closer look. Radium is a naturally occurring element that can sit in certain bedrock layers in and around St. Charles County, and water that passes through those layers can carry it. Finding it in a test does not by itself tell you that your water is unsafe. It does give you a clear reason to test instead of guessing.
What radium and gross alpha are
Radium is a naturally occurring radioactive element. Gross alpha is a screening measurement that reports the total alpha activity in a water sample without identifying each source. A gross alpha result that needs follow-up usually leads to a more specific test for radium, and sometimes uranium, because the screen alone does not say which element is responsible.
Radium and uranium are more often a question in deep wells that draw from bedrock than in shallow wells near the surface. Shallow wells have their own common problems, such as nitrates and bacteria, which are separate issues. This guide stays with deep wells.
Why deep wells differ
Water in deep bedrock has been in contact with rock for a long time. That contact can dissolve minerals, including naturally occurring radioactive ones. Because the source is the rock itself, the level can differ from one well to the next, even between homes on the same street. A neighbor's result is a useful starting point, but it is not a substitute for testing your own well.
Testing steps at home
- Find your well log or driller's record if you have one. It may list the depth of the well and the rock formation it was drilled into.
- Check whether any radium or gross alpha test was done when the well was completed or when you bought the house.
- Contact a laboratory certified to analyze drinking water. Ask whether it tests for gross alpha, radium, and uranium, and how it wants the sample collected.
- Ask the MO State Public Health Lab what it offers for private wells. It is a known source for private well bacteria and iron bacteria testing, and it may be able to point you to radionuclide testing as well. Ask directly rather than assuming.
- Follow the lab's sample instructions exactly, including the container type, whether to run the tap first, and how quickly the sample must reach the lab.
Reading the results
A lab report lists each test with a result and a reporting limit. A result marked as not detected means the test did not find the element above that lab's reporting limit for that method. Keep the full report, not only the summary page, and note the collection date.
If a gross alpha or radium result is high, the usual next step is a confirmation test and a conversation with a qualified water professional or your county health office about options. Do not make treatment decisions based on a single sample. A confirmation sample helps you avoid acting on an unusual reading.
What to do while you wait
- Keep using your water as you normally would until you have results and advice from your lab or local health office.
- Do not rely on boiling to remove radium. Boiling does not remove dissolved radium.
- Keep the well cap and casing sealed so surface material stays out. This does not address radium, but it protects the well against the other issues that shallow and deep wells share.
Treatment choices in plain terms
Treating radium is a separate question from softening. Whether any device removes radium depends on the device and the element involved, so do not assume a softener addresses it. Ask any treatment provider for performance data on radium specifically, not general claims. Keep the decision tied to your results, your lab, and your local health office.