What EPA's radon map says about Northwest Hills Planning Region

EPA's Map of Radon Zones does not carry a rating for Northwest Hills Planning Region under its current boundaries — the map dates to 1993 and this county's borders have changed since (see the coverage gaps guide).

Where Northwest Hills Planning Region sits nationally

About 114,101 people live in Northwest Hills Planning Region, Connecticut, spread over 786.642 square miles. Population density there runs about 145 people per square mile.

What this actually means for a house in Northwest Hills Planning Region

EPA's 4 pCi/L action level and the roughly 1.3 pCi/L national indoor average apply to Northwest Hills Planning Region the same as anywhere, even without a zone rating to place it against. EPA's guidance is unchanged by the absence of a zone rating here: test every home, since a zone (where one exists) only describes a county-wide average, never an individual house.

Testing and mitigation in Northwest Hills Planning Region

Mitigation cost doesn't depend on Northwest Hills Planning Region's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Connecticut's state radon program

Northwest Hills Planning Region's test kit answers today; a Airthings radon monitor keeps answering for Northwest Hills Planning Region over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. See the coverage gaps guide for the full list of boundary changes EPA's map predates.