New Hampshire Radon Well Testing

Radon is a colourless, odourless gas formed from the radioactive breakdown of uranium in soils and rocks. It can accumulate in enclosed spaces like residential and commercial buildings and cause significant health risks for building occupants. The gas is emitted into the air by groundwater containing high concentrations of uranium and other minerals or by building materials such as granite block foundations and some fireplace materials. Radon in water can escape into indoor air during use of household appliances such as showering, dishwashing and laundry, raising radon levels in the house. Although radon is present in the drinking water of many community water suppliers, the levels are usually much lower than those found in well water. The EPA recommends that a maximum contaminant level (MCL) of 10,000 picocuries per liter (pCi/L) be set for radon in drinking water.

In New Hampshire a large percentage of homes are served by private water wells. Many of these are bedrock wells, (aka drilled wells) which are more likely to contain elevated radon levels than shallow sand and gravel-based wells. The southeastern and eastern parts of the state are particularly at risk for radon in water.

Most private wells are not tested for radon, even though the EPA radonbrønn pris and MassDEP recommend that all private well owners test their water for radon. Some local Boards of Health and mortgage lenders may require testing. Currently there is no federal drinking water standard for radon, but a number of states have established maximum contaminant levels for radon in public supplies.

There is no enforceable federal requirement to test for radon in water; however, testing is available through private laboratories and the EPA’s certified tester network [exit DNR]. A list of options and EPA certified contractors is also available through the Wisconsin Department of Health [exit DNR].

The radon in water in New Hampshire is normally low, but since NH has a high percentage of bedrock wells, it is important that all wells be tested regularly. Since the dissolved radon in water escapes into indoor air, it can raise radon levels in the home significantly, especially if the building is situated near a geologic formation with high radon content.

Dissolved radon in well water rises to indoor air during use of household appliances such as water heating, showering and washing dishes. It is estimated that every 10,000 pCi/L of radon in water is expected to raise indoor radon levels by 1 pCi/L.

Radon levels in a home’s drinking water can also be elevated by a poorly sealed and insulated basement. It is a good idea to check for radon in basements as well as in the living space above. If the radon in well water is high it may be possible to reduce radon levels by connecting to a public water supply or installing an aeration system within the well. This could cost between $3,000 and $6,000. See our section on “Well Water Treatment Systems” for more information.