New London County, CT: Radon Risk Data
EPA predicts average indoor levels above 4 pCi/L · Source: EPA, CDC
Tipper's take on New London County
New London County is in EPA Zone 1, the highest risk classification. The EPA's geological and indoor measurement data predicts average indoor radon levels above 4 pCi/L here, which is the agency's action level. CDC testing data from New London County puts the average measured radon level at 4 pCi/L.
Zone 1 doesn't mean every home is over the limit. Radon varies house to house depending on foundation type, construction, soil, and ventilation. A well-sealed Zone 1 home might test at 2 pCi/L. A cracked basement in a Zone 3 county might test at 9 pCi/L. The zone tells you about area-level risk. Your test result tells you about your home.
Zone 1 is a meaningful signal, though. If you live in New London County and haven't tested, you should. A basic test kit runs about $15 and gives you a result in 48 hours.
Sources: EPA Radon Zone Map, CDC Environmental Public Health Tracking Network
Test Your Home
The only way to know your home's radon level is to test it. Tipper recommends starting with a short-term test kit. It includes the lab fee, takes 48 hours, and costs about $15.
Radon Professionals Serving Connecticut
No contractors in our directory are listed specifically for New London County. These certified pros serve Connecticut and may cover your area. Call to confirm.
How New London County Compares
vs. Connecticut Statewide
New London County's average of 4 pCi/L is 0.3 pCi/L below the statewide average.
Frequently Asked Questions: New London County
My home is in Zone 1. Does that mean it's definitely dangerous?
Not automatically. Zone 1 means the EPA expects area-wide average indoor levels above 4 pCi/L. That's an average across many homes with different foundations, construction types, and ventilation. A well-sealed Zone 1 home on a concrete slab might test at 1.5 pCi/L. Test first, then decide. The zone tells you to take it seriously. Your test result tells you what to do.
What is the EPA's action level, and why 4 pCi/L?
The EPA recommends fixing your home if it tests at or above 4 pCi/L (picocuries per liter). There's no completely safe level. Radon exposure is a spectrum. But 4 pCi/L is where the EPA concludes mitigation is clearly cost-effective. The WHO sets a lower reference level of 2.7 pCi/L. If your home is between 2 and 4 pCi/L, mitigation is optional but worth considering, especially in bedrooms.
How often should I retest for radon?
If your home tested below 4 pCi/L and nothing major has changed structurally, retesting every two years is a good habit. Retest immediately after any significant basement renovation, after buying or selling a home, or after installing a mitigation system (to confirm it's working). Radon levels can shift as foundations settle and conditions change.
Is radon worse in basements than upper floors?
Generally, yes. Radon enters through foundation cracks, floor-wall joints, and gaps around pipes, all concentrated at ground level. Basement living spaces and bedrooms tend to have the highest concentrations. Upper floors typically have lower levels, though radon can still build up in poorly ventilated rooms. Test in the lowest livable level of your home first.