Average Radon Levels in Virginia: EPA Zone Data and What It Means

Virginia Is Unique: All Three EPA Zones in One State

Most states fall cleanly into one or two EPA radon zones. Virginia spans all three, which makes it one of the most geologically varied radon environments in the country. A homeowner in Staunton faces dramatically different radon risk than a homeowner in Virginia Beach, even though they live in the same state. Understanding which zone your county falls in, and why, gives you a much clearer picture of your actual risk than any statewide average.

The EPA Zone System Explained

The EPA divides U.S. counties into three radon potential zones:

Zone 1: Predicted average indoor radon screening level above 4 pCi/L. The EPA considers immediate testing essential for all homes.
Zone 2: Predicted average between 2 and 4 pCi/L. Testing is recommended for all homes.
Zone 3: Predicted average below 2 pCi/L. Testing is still recommended, because individual homes in any zone can exceed 4 pCi/L.

Zone classifications are county-level averages derived from geology, soil permeability, aerial radiometric surveys, and historical housing data. They describe what is typical, not what any individual home will measure. Testing is the only way to know your home’s actual radon level.

Zone 1 Counties: Western Virginia

Virginia’s Zone 1 counties run along the western spine of the state, covering the Blue Ridge province, the Shenandoah Valley, and portions of the Allegheny Highlands. Counties with EPA Zone 1 designations include: Shenandoah, Warren, Page, Rockingham, Augusta, Bath, Highland, Craig, Montgomery, Floyd, and Carroll.

These counties sit on geology that produces some of the highest indoor radon readings in the eastern United States. The Blue Ridge metamorphic province, which runs through Waynesboro, Staunton, and the mountain communities west of Charlottesville, is underlain by schists and gneisses with high uranium concentrations. As uranium decays to radium and then to radon gas, the gas migrates upward through fractured bedrock and into building foundations.

The Shenandoah Valley, which encompasses Winchester, Harrisonburg, and the communities along Route 81, sits on a different geology: carbonate karst formed from limestone and dolomite. Karst terrain presents a different radon pathway. Sinkholes, fractures, and solution channels created by millennia of water dissolving carbonate rock create direct conduits for radon to travel from depth to the surface. Homes built over karst, particularly those with basements or crawlspaces, are exposed to radon at higher concentrations and faster transport rates than homes on dense crystalline rock.

For residents of communities like Waynesboro, Staunton, Harrisonburg, Front Royal, Luray, Woodstock, and Winchester, assuming elevated radon and testing accordingly is the practical approach. These markets consistently show elevated test results.

Zone 2 Counties: Piedmont, Northern Virginia, and Parts of Western Virginia

Virginia’s Zone 2 counties span a broad mid-state band from Northern Virginia through the Piedmont to portions of western Virginia. Named Zone 2 counties include: Fairfax, Loudoun, Prince William, Fauquier, Culpeper, Madison, Orange, Albemarle, Rockbridge, Roanoke, Henry, and Patrick.

The Piedmont geological province underlies most of this zone. Piedmont geology consists of crystalline basement rocks, including granites, gneisses, and metamorphics formed during ancient continental collisions. These rocks contain moderate uranium concentrations, enough to produce radon at levels that frequently exceed 4 pCi/L in homes with basements or slab-on-grade construction over permeable soils.

Northern Virginia, which includes Fairfax, Loudoun, and Prince William counties, deserves particular attention within Zone 2. The EPA zone map shows these counties at moderate predicted average levels, but the map does not account for a critical local factor: housing stock. Northern Virginia has a very large inventory of split-level and raised-ranch homes built during the 1960s and 1970s suburban expansion. These floor plans place finished living space directly in contact with below-grade foundations, creating highly efficient radon accumulation conditions. Many individual NoVA homes in Reston, Burke, Springfield, Centreville, Herndon, and Manassas test well above 4 pCi/L despite sitting in a Zone 2 county.

Albemarle County, home to Charlottesville, sits on Piedmont crystalline basement with localized Blue Ridge influence to the west. The Charlottesville area sees moderate to elevated radon, and testing during real estate transactions is routine. Roanoke City and Roanoke County straddle the boundary between Piedmont geology and the Valley and Ridge province, producing variable radon levels that make individual testing especially important.

Zone 3 Counties: The Coastal Plain

Virginia’s Zone 3 counties cover most of the Coastal Plain, the low-lying terrain east of the fall line that extends to the Chesapeake Bay and Atlantic coast. Counties in or predominantly in Zone 3 include: York, James City (Williamsburg), King William, Essex, Westmoreland, Northumberland, Accomack, and Northampton, along with most of the Hampton Roads core: Virginia Beach, Norfolk, Chesapeake, Suffolk, Portsmouth, Hampton, and Newport News.

The Coastal Plain is underlain by Cretaceous and Tertiary sediments deposited over millions of years by rivers flowing eastward from the Appalachians. These sediments have very low uranium content. Without uranium in the soil and rock, the decay chain that produces radon gas does not generate significant concentrations. Radon levels in Zone 3 homes are typically well below 4 pCi/L.

That said, Zone 3 is a county-level average, not a guarantee for any individual property. Foundation type, construction details, and localized soil conditions can produce elevated readings even in low-zone areas. The EPA recommends testing every home regardless of zone, and a professional test in Hampton Roads costs $125 to $200: a modest investment for confirmed peace of mind.

What This Means Region by Region

Blue Ridge and Shenandoah Valley

Homeowners in the Shenandoah Valley and Blue Ridge should approach radon testing with the expectation that elevated results are common. Professional estimates suggest 40 to 60 percent of homes in Zone 1 Virginia counties test above 4 pCi/L on initial screening. Older stone foundations, basements over karst, and homes in mountain hollows where cold air settles and creates stack effect conditions are particularly high risk. If you have not tested, do so. If you have a mitigation system, re-test every two years as recommended by the Virginia Department of Health.

Northern Virginia

Fairfax County alone has over 400,000 housing units. A significant share of those units are below-grade or split-level homes that trap radon. The NoVA real estate market treats radon testing as a standard inspection item, and agents routinely include radon contingencies in purchase contracts. Buyers who have not tested their current homes should not assume their Zone 2 designation means low levels. Independent testing remains the only definitive answer.

Charlottesville and Central Virginia

Albemarle County and surrounding Piedmont counties see moderate radon, with enough Zone 1 geology influence from the Blue Ridge to push individual properties above 4 pCi/L. Testing before buying or selling is standard practice in this market.

Hampton Roads and the Eastern Shore

Virginia Beach, Norfolk, Chesapeake, the Northern Neck, and the Eastern Shore (Accomack and Northampton counties) sit on low-uranium sediments. Most homes here test low. Radon is a lower-priority concern in these markets but is still worth testing, especially for buyers relocating from higher-radon states who want baseline documentation.

Health Risk at Different Radon Levels

Radon is the leading cause of lung cancer among non-smokers and the second leading cause overall, responsible for roughly 21,000 deaths per year in the United States. The risk scales with concentration and duration of exposure:

1.3 pCi/L: Average outdoor radon level.
4 pCi/L: EPA action level. Equivalent lung cancer risk to smoking approximately 8 cigarettes per day.
8 pCi/L: Equivalent to smoking roughly half a pack per day.
20 pCi/L: Risk comparable to smoking 1 to 2 packs per day.

Mitigation reduces indoor radon by 80 to 99 percent. The Virginia Department of Health supports radon testing and mitigation statewide through its Radiological Health program.

Find a Certified Radon Tester in Virginia

The only way to know your home’s radon level is to test it. Professional testing in Virginia costs $125 to $350. Our directory lists certified radon testers in Virginia who hold NRPP or NRSB certification as required by VDH, covering all regions of the state from Northern Virginia and the Shenandoah Valley to Richmond, Roanoke, and Hampton Roads.

Frequently Asked Questions

Does Virginia have high radon levels?

It depends on where in Virginia you live. Western Virginia, the Blue Ridge, and the Shenandoah Valley are among the highest-radon areas in the eastern United States. Northern Virginia and the Piedmont corridor are moderate to high. Hampton Roads and the Coastal Plain are generally low, though individual homes can still test above 4 pCi/L even in low-zone areas.

What EPA radon zone is my Virginia county in?

Virginia spans all three EPA zones. Zone 1 (highest predicted average) includes most of western Virginia: Shenandoah, Warren, Page, Rockingham, Augusta, Bath, Highland, Craig, Montgomery, Floyd, and Carroll counties. Zone 2 (moderate) includes Fairfax, Loudoun, Prince William, Fauquier, Culpeper, Madison, Orange, Albemarle, Rockbridge, Roanoke, Henry, and Patrick. Zone 3 (lowest predicted average) covers most of Hampton Roads and the Coastal Plain.

What percentage of Virginia homes test above 4 pCi/L?

Roughly 1 in 4 Virginia homes statewide tests above 4 pCi/L, the EPA action level. That proportion varies sharply by region: it is much higher in western Zone 1 counties and lower in Coastal Plain areas. The statewide average understates risk in high-geology areas and overstates it in the Tidewater region.

Why does Northern Virginia have radon if it is not in Zone 1?

Fairfax, Loudoun, and Prince William counties sit in Zone 2 on the EPA map, meaning predicted average levels of 2 to 4 pCi/L. But the EPA zone map shows county averages, not individual home risk. NoVA is built on Piedmont crystalline basement rock, which contains moderate uranium. The large inventory of split-level and raised-ranch homes from the 1960s and 1970s traps soil gas more effectively than modern construction. Many individual NoVA homes test well above 4 pCi/L.

Should I test my Hampton Roads home for radon?

Yes. Hampton Roads sits in Zone 3, the lowest predicted average category, but that does not mean individual homes cannot have elevated radon. Localized geology, foundation type, and construction details all affect indoor radon regardless of zone designation. The EPA recommends testing every home. A $125 to $200 professional test gives you certainty that a zone map cannot.