About and method

Radon Zone Map shows EPA radon zones by county. It is independent and has no link to EPA.

• Zones come from EPA's Map of Radon Zones, published in 1993 and posted by EPA as one map per state, linked on every county page.
• EPA's state maps show zones as colours. We read each county's zone from the colour around its name on EPA's map, and publish it only when that reading is clear. Counties where the label sits on a border or could not be read are left out until checked by hand.
• If a source does not say something, we say so. We never fill gaps from memory or guesses.
• Connecticut, Indiana and Virginia maps use a different layout and are being added by hand.

Corrections

Report a change and it will be checked against the official source and dated in the change log. No payment is accepted to change, add or remove anything.