Radon in Well Water: What York County Homeowners Should Know
Most radon conversations focus on the air in a home — the soil-gas pathway that a standard test and a mitigation system address. If your home draws water from a private well rather than a municipal system, there's a second, separate pathway worth understanding: radon dissolved directly in the water itself.
How radon gets into well water
Radon forms from the natural breakdown of uranium in rock and soil — the same geologic process behind York County's elevated indoor air readings, driven by the carbonate and slate/schist formations documented on York County radon levels. Groundwater moving through that rock can dissolve radon gas directly into it. A private well draws water straight from that underground source with no treatment step in between, which is why well water is a more relevant radon pathway than a municipal supply — some public water systems treat their water in ways that let dissolved radon dissipate before it reaches a tap, reducing (though not necessarily eliminating) that pathway for homes on a municipal connection. If your home is on a private well rather than a municipal system, this is worth addressing separately from the standard air-testing conversation above.
Two ways radon in water can reach you
- Inhalation — running water releases dissolved radon into the air, most noticeably during showers, dishwashing, and laundry. This adds to whatever airborne radon is already entering the home through the foundation.
- Ingestion — drinking water with dissolved radon is a secondary pathway, generally considered a smaller contributor to overall risk than inhalation, but not a zero one.
Source: EPA, "A Consumer's Guide to Radon Reduction".
Water testing is separate from air testing
A standard radon test kit measures airborne radon, not what's dissolved in your water. If you're on a private well, testing the water itself requires a separate water sample, collected and analyzed according to the specific protocol your testing lab provides. Worth knowing: PA DEP lists water-radon testing and lab providers as a resource, but — unlike air-testing and mitigation professionals — it doesn't certify them, so "PA DEP-certified" isn't the right term to look for on the water-testing side (per PA DEP's radon certification program page). You can't infer your water's radon level from an indoor air test result, and vice versa. If your home has both elevated indoor air and a private well, addressing the air pathway (through sub-slab depressurization or the crawl-space equivalent) doesn't address the water pathway, and needs to be evaluated on its own.
If your well water tests high
Two treatment approaches are commonly used to reduce radon in water before it reaches your taps: aeration systems, which bubble air through the water to release dissolved radon before it enters the home's plumbing, and granular activated carbon (GAC) filtration, which adsorbs radon as water passes through. Which approach fits depends on your water system's setup and the concentration involved — this is a specialized water-treatment decision, distinct from the air-side mitigation contractors handle, and worth discussing directly with a water-treatment professional or PA DEP if your well tests high.
What this means for your home
If you're on a private well, treat air and water as two separate questions: test your indoor air the way any York County homeowner should, and if you want a full picture, test your well water too — especially if your indoor air result comes back elevated and you want to understand every source contributing to it. Neither test substitutes for the other.
Get a Free Radon Estimate for an indoor air test, and ask us about water-testing options if you're on a private well.