Radon zones in District of Columbia

Last updated

EPA’s Map of Radon Zones places District of Columbia in its three radon potential zones: 0 in Zone 1 (highest), 0 in Zone 2 (moderate), and 1 in Zone 3 (low).

0Zone 1 · Highest potential
0Zone 2 · Moderate potential
1Zone 3 · Low potential

What this means for District of Columbia homes

EPA predicts lower average indoor levels (below 2 pCi/L) across much of District of Columbia. That does not mean your home is low: EPA notes that elevated levels are found in Zone 3 counties too.

EPA’s guidance is the same everywhere: test your home, fix it if the level is 4 pCi/L or higher, and consider fixing between 2 and 4 pCi/L. The zone map is from 1993 and should not be used to decide whether a single home needs testing.

District of Columbia radon program

EPA lists the following state contact for District of Columbia: DC Department of Energy and the Environment, phone 202-535-2600. Website: doee.dc.gov/node/9482. State programs can tell you about local testing data, free or discounted test kits, disclosure rules for home sales, and credentialed radon professionals.

District of Columbia counties and their EPA radon zones

CountyEPA radon zone
District of ColumbiaZone 3

County names follow the 2020 Census. Zones from the EPA Map of Radon Zones (text version). Rows marked “zone of” use the zone EPA gave the predecessor or surrounding county.

Next steps: read how to test your home, check a result with the level calculator, or look up a single address by ZIP code.

Sources

  1. U.S. EPA, EPA Map of Radon Zones (text version)
  2. U.S. EPA, EPA Map of Radon Zones and Supplemental Information (state radon contacts)
  3. U.S. EPA, EPA Maps of Radon Zones and Supporting Documents by State