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Radon Levels in Sherman County, Oregon

EPA puts Sherman County in Zone 2, its middle radon zone, and only 1 radon test from it is on file with CDC (2019). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

  • Highest bordering

    10.0%

    Wasco County

    Wasco
    10.0%

    1 of 3 neighbours have 30+ tests, 2016

  • Nearest county

    10.0%

    Wasco County, 29 miles

    Wasco
    10.0%
    Oregon
    21.5%

    Share at 4+ pCi/L, 30 tests, 2016

  • Ground above low

    100.0%

    37.7 pts above Oregon

    Sherman
    100.0%
    Oregon
    62.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    3

    Too few for a share

    Sherman
    3
    Needed
    30

    2014

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

Read a result for Sherman County

Starts at EPA's action level

4.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.

The data

Sherman County, At a glance

Sherman County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Sherman County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Sherman County, 2019

Share of reported tests at or above 4 pCi/L, by year, Sherman County
Share of reported tests at or above 4 pCi/L, by year, Sherman County
YearShare of reported tests at or above 4 pCi/L
201433.3%
20150.0%
20160.0%
20190.0%

2019: 0.0%. Across these years the share ran from 0.0% to 33.3%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 1 test was reported to CDC for Sherman County over 2019, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2019. Measured data period: 2014 to 2019 (every CDC figure on file).

How to read these figures

Sherman County, Compared

Sherman County radon figures, compared

Calculated by Radon411

CDC's largest figure for Sherman County rests on 3 tests in 2014, 1 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 4.8 pCi/L, with a middle value of 1.5 pCi/L.

Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L. Farther out, Hood River County (47 miles away) at 20.8%, Clackamas County (76 miles away) at 17.9% and Multnomah County (84 miles away) at 28.6% have figures too. Pooled across 35 Oregon counties, 21.5% of reported tests reached that level; across every county in the country with a figure, 31.2%.

Statewide for the same period, Union County reported the highest share (39.1%) and Deschutes County the lowest (6.7%). EPA's 1993 map puts Sherman County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Oregon, the United States and the counties around Sherman County, 2016
AreaTestsAt or above 4 pCi/LMedian
Oregon, pooled35 counties, pooled5,91721.5%Not pooled
United States, pooled886 counties, pooled398,20731.2%Not pooled
Union Countyhighest in the state6439.1%3.3 pCi/L
Deschutes Countylowest in the state456.7%0.8 pCi/L
Klickitat County, WAborders it2714.8%2.1 pCi/L
Wasco County, ORborders it3010.0%0.8 pCi/L
Gilliam County, ORborders it10.0%0.4 pCi/L
The nearest Oregon counties to Sherman County with 30 or more tests, 2016
CountyDistanceTestsAt or above 4 pCi/LMedian
Wasco County29 mi3010.0%0.8 pCi/L
Hood River County47 mi5320.8%1.7 pCi/L
Clackamas County76 mi84317.9%1.6 pCi/L
Multnomah County84 mi2,51228.6%2.3 pCi/L
Marion County99 mi50819.7%1.8 pCi/L
Deschutes County106 mi456.7%0.8 pCi/L
Linn County110 mi539.4%1.0 pCi/L
Washington County118 mi93611.9%1.2 pCi/L
Sherman County radon tests by year, against Oregon's pooled share
YearTestsAt or above 4 pCi/LMedianHighestOregon, pooledChange from the row before
201910.0%1.5 pCi/L1.5 pCi/L20.2%Level
201620.0%0.7 pCi/L0.8 pCi/L21.5%Level
201510.0%0.4 pCi/L0.4 pCi/L27.4%−33.3 points
2014333.3%1.5 pCi/L4.8 pCi/L25.1%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Sherman County, Geology

The ground under Sherman County

Predicted

USGS's geologic map puts all of Sherman County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Deschutes Umatilla Plateau, to which USGS gives a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under Sherman County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Deschutes Umatilla PlateauTertiary basalt, basaltic breccia, tuffaceous sedimentary rocks and tuff. Elevated uranium in soils.Moderate9100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Sherman County beside the ground around it

Sherman County has more moderate-potential ground than Oregon as a whole: 100% of its land against 62.3%. Of the 3 counties that border it, none has as large a share of moderate-potential ground; Gilliam County comes nearest at 100%.

Share of land by USGS radon potential: Sherman County, the 3 counties bordering it and Oregon
AreaEPA zoneLow potentialModerate potentialHigh potential
Sherman CountyZone 2None100%None
Gilliam CountyZone 2None100%None
Wasco CountyZone 25.0%95.0%None
Klickitat County, WAZone 29.8%90.2%None
Oregon36 counties, pooled by land areaVaries37.5%62.3%None

The map rates the ground, not the air in any home.

What it means

Sherman County, Questions

Questions about radon in Sherman County

Are radon levels high in Sherman County?

In 2019, 0.0% of the radon tests reported to CDC for Sherman County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L.

Which counties border Sherman County?

Sherman County borders 3 counties: Gilliam County, OR, Wasco County, OR and Klickitat County, WA.

Products

Sherman County, Products

Testing a home in Sherman County

No CDC figure names Sherman County; the nearest county with one, Wasco County (29 miles away), reported 10.0% of its tests at or above 4 pCi/L in 2016, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Sherman County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Sherman County homes, compared

Explore

Sherman County, Bordering counties

Counties bordering Sherman County

Calculated by Radon411

Sherman County, Cities and towns

Cities and towns in Sherman County

Sherman County is growing: the Census Bureau puts it at 2,051 residents on July 1, 2025, up 9.1% from 1,880 in 2020. Spread over its land, that is 2.5 people to the square mile. Its largest town, Wasco, has 457 residents, 22.3% of the total. Together its 4 incorporated places hold 64.5% of those residents; the other 35.5% live outside any of them. CDC's 3 reported tests for 2014 work out to 1.5 per 1,000 residents (2025 estimate), close to Oregon's 1.3.

From Wasco to Grass Valley, CDC publishes no figure by town: each reads Sherman County's.

The cities and towns in Sherman County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Wasco457+9.3%22.3%
Moro403+8.9%19.6%
Rufus292+9.8%14.2%
Grass Valley170+11.8%8.3%

4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).

Sherman County, Homes

Homes in Sherman County

Of Sherman County's 979 homes, 63% are detached houses, against 63% across Oregon; 30% are mobile homes. The homes are older than Oregon's as a whole: half were built before 1956 (1980 for Oregon), and 53% date from before 1960. 67% of occupied homes are lived in by their owner (Oregon: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Sherman County, Oregon, 2019 to 2023
HomesSherman CountyOregon
Housing units9791,838,631
Detached houses63%63%
In buildings of 5 or more2%17%
Mobile homes30%8%
Built before 196053%23%
Built since 200014%24%
Middle year built19561980
Owner-occupied67%63%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.