If your St. Charles home runs on a private well, or if you simply want to understand what comes out of your taps, radon is worth a closer look. Radon is a naturally occurring gas that can move from rock and soil into groundwater. Once dissolved in water, it can escape into the air when the water is agitated, such as during showers, dishwashing, or running a faucet into a sink. This guide explains how water can add to indoor air and what a homeowner can do next.
Why water can add to indoor air
Most homeowners think of radon as a soil gas that seeps in through the foundation. That route is real, and it is the one most radon test kits are designed to measure. Water is a second possible route. Radon that dissolves in groundwater can come out of solution when water splashes, sprays, or churns. The gas then mixes into the room where the water is being used, and it can build up in a small bathroom with the door closed.
Some groundwater carries naturally occurring radioactive elements, and radon is one of the gases that can come along with them. This matters most for homes on private wells. A well draws directly from the aquifer, so what is in the groundwater reaches your faucets unless you treat it. Public supply water is handled differently, but it is still worth knowing where your water comes from.
Separate the two sources before you test
Air testing and water testing answer different questions. A standard indoor air kit tells you what the room air contains, but it will not tell you whether a well is the source. Water testing uses a sample taken from a tap and analyzed by a lab. Some homeowners run both, so they can compare results and see whether a reading rises during or after water use.
- Use an air test kit in the main living area and in the bathroom you use most.
- Keep the test in place for the period the kit instructions describe, and keep windows and doors in normal use during that time.
- If you have a private well, ask a lab about testing the water for radon.
Simple checks you can do at home
- Note whether readings or odors rise after long showers or heavy water use.
- Run the bathroom fan during and after showers, and keep the bathroom door closed only while the shower is running if the test instructions allow it.
- Check whether the bathroom sits over a crawl space or basement, since soil gas can add to the picture.
- Write down the water source for each tap, including whether the house is on a public line or a private well.
What to do with results
A test result is a starting point, not a verdict. If air readings are elevated, the usual next step is a professional assessment of the building and its soil gas, along with a plan to reduce the gas. If the water is the source, any treatment decision should depend on what the lab found. Do not make changes to the well or the home based on a single reading without checking the method and the context.
Keep your test records with the home papers. If you sell the house or change its water system, those notes will help the next owner understand what has already been checked.
Staying on the right track in St. Charles
Homes in St. Charles vary. Some sit on public water, while others draw from wells that tap the groundwater near the Missouri River. Start by confirming the water source, then test the air where people spend the most time. Clear records and a patient, step-by-step approach will get you further than a quick guess.