What happens when radon in water is left untreated for years?
Radon is a naturally occurring radioactive gas that can dissolve into groundwater and enter your home's water supply. If radon remains in water over time, it can release into indoor air during normal water use, contributing to overall radon exposure. Long-term exposure to elevated radon levels in indoor air has been linked to increased lung cancer risk. However, radon levels in water vary and depend on the source, so untreated water may or may not significantly contribute to indoor radon. Monitoring and addressing radon in water can reduce this potential source of exposure.
How does radon enter groundwater in Dorchester County?
In Dorchester County, Maryland, radon originates from natural radioactive decay in underground rock formations. The U.S. Geological Survey sampled wells in the local aquifer 124PNPN, located between 402 and 568 feet deep. This natural process allows radon to dissolve into groundwater, which then flows into private wells and public water systems drawing from this aquifer. Because radon is a gas, it can easily escape into air once water is used inside the home.
How many samples and wells support what we know about radon here, and what does a small sample mean?
The USGS collected 8 separate measurements from different wells in the Dorchester County aquifer 124PNPN between May 2011 and July 2012. Radon levels ranged from 196 to 720 pCi/L, with a median of 325 pCi/L. Although this is a limited number of samples, they represent multiple independent wells and provide a general indication of radon presence in this aquifer. Small sample sizes mean local variations may exist, so individual wells could have higher or lower radon levels than reported here.
How do public system records differ from private well testing for radon?
The USGS data reflects groundwater from private wells in the aquifer rather than municipal treatment plants. Public water systems often treat or blend water sources to manage contaminants including radon, while private wells lack such controls. Testing your own well water is essential to know your specific radon concentration and treatment needs. Public records give a regional snapshot but cannot substitute for individual testing.
Can we interpret the median and range from these USGS results?
The median radon level of 325 pCi/L means half the wells had concentrations below this point and half above. The range between 196 and 720 pCi/L shows variability among wells sampled in the same aquifer. No federal health-based radon concentration limit was exceeded in these samples, but the levels are measurable and can influence household exposure. This range suggests some wells could have higher radon that existing equipment may struggle to manage fully.
Summary: Dorchester County's aquifer consistently shows detectable radon in groundwater, with regional measurements indicating moderate levels. To accurately assess your home's water radon and manage ongoing exposure, testing your private water supply is necessary. The Fleck Radon in Water Filter ships ready to configure as a targeted solution to reduce radon entering your home through water when additional treatment capacity is needed.
Where this information comes from
Source: USGS groundwater sampling. Sampled 2012-07-26. These figures describe groundwater sampled in this area. They are not a test of any individual private well - only a test of that well can establish its own water.
On record: U.S. Geological Survey sampling of Radon-222 in the 124PNPN aquifer (Dorchester County): 8 results from 8 wells, median 325.0 pCi/L, range 196.0-720.0 pCi/L; none above any federal threshold