What radon zone is District of Columbia, District of Columbia?

District of Columbia is EPA Radon Zone 3, which means the EPA predicts a predicted average indoor screening level below 2 pCi/L for the county. The EPA still recommends testing every home. Zone 3 is the lowest predicted tier, but individual houses in any county can and do read above the action level.

Does a Zone 3 classification mean my home is safe?

No. The EPA zone is a county-level planning estimate, not a measurement of any individual house. Radon varies dramatically from house to house on the same street. The only way to know your home's level is to test it.

District of Columbia, District of Columbia radon zone: EPA Zone 3

What Zone 3 means in District of Columbia

The EPA still recommends testing every home. Zone 3 is the lowest predicted tier, but individual houses in any county can and do read above the action level.

The EPA's Map of Radon Zones (EPA-402-R-93-071) sorts all 3,143 US counties into three tiers by predicted indoor screening level. District of Columbia sits in Zone 3. The classification is a planning assumption for builders, inspectors and buyers, and it is the figure a home inspector or realtor will cite for this county.

How District of Columbia compares inside District of Columbia

Of the 1 counties in District of Columbia on the EPA map, 0 are Zone 1, 0 are Zone 2 and 1 are Zone 3. District of Columbia is one of the 1 District of Columbia counties classified Zone 3.

Why your own home still needs a test

Radon comes out of the soil and enters through the foundation, so two houses on the same street can read very differently depending on foundation cracks, soil contact and how the house is ventilated. A Zone 3 classification tells you the county's planning assumption, not your reading. A short-term test kit costs about $15 to $30 and settles it. Many state radon programs also offer free or low-cost kits.

ZIP codes in District of Columbia

20001, 20002, 20003, 20004, 20005, 20006, 20007, 20008, 20009, 20010, 20011, 20012, 20013, 20015, 20016, 20017, 20018, 20019, 20020, 20022, 20024, 20026, 20027, 20029, 20030, 20032, 20033, 20035, 20036, 20037, 20038, 20039, 20040, 20041, 20042, 20043, 20044, 20045, 20047, 20049, 20050, 20052, 20053, 20055, 20056, 20057, 20058, 20059, 20060, 20061, 20062, 20063, 20064, 20065, 20066, 20067, 20068, 20069, 20070, 20071 and 217 more

Get the full dossier for your ZIP

The $9 District of Columbia radon report gives you the county's EPA zone, the expected indoor average, your home's estimated likelihood of testing above the 4 pCi/L action level adjusted for basement and home type, the mitigation cost band, and the EPA lifetime-risk figures, on one printable page you can hand to a buyer's inspector.

Check my radon zone · $9

Source

Zone classification: US EPA Map of Radon Zones, county table (EPA-402-R-93-071 / EPA 402/A-16/001). Population: US Census Bureau county population estimates, 2024 vintage. This page reports the EPA's own classification for District of Columbia exactly as published. We do not interpolate or adjust it.

District of Columbia, District of Columbia is in EPA Radon Zone 3