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Radon Levels in Lyman County, South Dakota

Zone 1Highest predicted potential1,707 square miles · 10 bordering counties

What this means for you

  • Your area: EPA rates Lyman County Zone 1, the highest of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
  • Local tests: Of 2 radon tests reported to CDC for Lyman County (2008 to 2017), 100.0% were at or above 4 pCi/L, EPA's action level.
  • Your home: The only way to know your home’s level is to test it.

pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.

Over the 2008 to 2017 laboratory totals, 100.0% of the radon tests reported to CDC for Lyman County, South Dakota came back at or above the EPA action level of 4 pCi/L, and the median result was 22.1 pCi/L. EPA's Map of Radon Zones places the county in Zone 1, highest predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county as a whole.

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

USGS geologic potential: Low across 56% of the county's land area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Lyman County, 2008 to 2017, laboratory

Tests reported
2
At or above 4 pCi/L
100.0%
Median result
22.1 pCi/L
Reported results by concentration band, Lyman County, 2008 to 2017, laboratory
Under 2 pCi/L: 0%2 to 4 pCi/L: 0%4 pCi/L and above: 100%

Of 2 pre-mitigation tests reported to CDC, not homes in this area. CDC publishes the share in each band, not a count per band, so the per-band counts in the table are calculated by Radon411 and rounded to add up to the published total.

Reported results by concentration band, Lyman County, 2008 to 2017, laboratory: data table
Result bandTests Calculated by Radon411Share Measured
Under 2 pCi/L00.0%
2 to 4 pCi/L00.0%
4 pCi/L and above2100.0%

Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

Lyman County, In figures

Lyman County in figures

What the published data says about Lyman County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places Lyman County in Zone 1, highest predicted potential, as it does 47 other counties of South Dakota's 66.

      Of the 10 bordering counties, EPA places Brule County, Buffalo County, Charles Mix County, Hughes County, Hyde County and Stanley County in Zone 1 and Gregory County, Jones County, Mellette County and Tripp County in Zone 2.

  • Reported tests

    Measured

    CDC publishes no annual figure for Lyman County; its figure is a laboratory total for 2008 to 2017: 100.0% of 2 reported tests were at or above 4 pCi/L.

  • Local record

    South Dakota's radon program and its page are under Local resources.

    The county's largest incorporated places are Presho, Oacoma and Kennebec; the figures here cover them as part of the county.

Lyman County, Comparison

How Lyman County compares

Measured

Lyman County's own published CDC figures beside those of the counties that border it, for the same period.

Share of reported tests at or above 4 pCi/L

Measured

2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.

  1. Lyman CountyThis page2 tests100.0%
  2. Jones CountySD8 tests75.0%
  3. Hughes CountySD71 tests70.4%
  4. Brule CountySD37 tests67.6%
  5. Gregory CountySD15 tests66.7%
  6. Stanley CountySD3 tests66.7%
  7. Charles Mix CountySD28 tests60.7%
  8. Hyde CountySD7 tests57.1%
  9. Tripp CountySD9 tests55.6%

Median reported result

Measured

2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.

  1. Lyman CountyThis page2 tests22.1 pCi/L
  2. Jones CountySD8 tests20.8 pCi/L
  3. Charles Mix CountySD28 tests6.5 pCi/L
  4. Brule CountySD37 tests6.4 pCi/L
  5. Hughes CountySD71 tests5.7 pCi/L
  6. Gregory CountySD15 tests5.3 pCi/L
  7. Hyde CountySD7 tests4.9 pCi/L
  8. Stanley CountySD3 tests4.2 pCi/L
  9. Tripp CountySD9 tests4.2 pCi/L

Each figure is that county’s own published CDC figure for 2008 to 2017, laboratory, counting radon tests reported to CDC, not homes. Lyman County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2008 to 2017, laboratory: Buffalo County, SD; Mellette County, SD. Every South Dakota county’s own figure is in the South Dakota county table.

CDC publishes this figure only for counties here, so there is no state or national number to compare Lyman County, South Dakota with.

Lyman County, Bordering counties

Counties bordering Lyman County

Calculated by Radon411

Lyman County, Local resources

Local resources in South Dakota

Who to ask in South Dakota: the state's radon program, test kits and professionals.

South Dakota's radon program

Department of Agriculture and Natural Resources

South Dakota’s radon program answers questions about testing, mitigation and the rules where you live.

Phone
1-800-438-3367
Visit the program's page(opens in a new tab)

Test kits

The program says: The Department of Agriculture and Natural Resources (DANR) will provide 500 free Radon test kits to South Dakota Residents.

Radon professionals

2 professionals are listed in South Dakota.

Professionals in South Dakota

Lyman County, Cities and towns

Cities and towns in Lyman County

The radon figures on this page are for Lyman County as a whole. They do not differ by city or town.

  • Presho
  • Oacoma
  • Kennebec
  • Reliance

4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.

Lyman County, Questions

Questions about radon in Lyman County

Common questions8 questions, answered from the figures above

Are radon levels high in Lyman County?

In 2017, 100.0% of the radon tests reported to CDC for Lyman County, South Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 22.1 pCi/L. That is a share of reported tests, not of homes. EPA places Lyman County in Zone 1, highest predicted potential, a predicted average indoor screening level greater than 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

What a radon level meansRadon in South Dakota

How do I get a radon test in Lyman County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Lyman County as a service area yet. The South Dakota radon program is the place to ask about certified testers and any test kit offer it runs.

How to test a homeTest kits comparedFree and low-cost kits by stateSouth Dakota radon program

Who does radon mitigation in Lyman County?

No listed mitigator names Lyman County as a service area yet; the South Dakota directory lists 2 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether South Dakota requires one.

How radon mitigation worksWhat mitigation costsMitigators in South Dakota

What EPA radon zone is Lyman County in?

EPA places Lyman County, South Dakota in Zone 1, which EPA describes as highest predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in Lyman County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border Lyman County?

Lyman County borders 10 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

What these figures mean if you own, buy, sell or rent

The reported-test figures on this page describe Lyman County, South Dakota in 2017. They describe tests other people carried out in other buildings, and none of them measures yours.

  • If you own your home

    Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.

    How to test a home
  • If you are buying

    Ask for past results and any system's post-mitigation test, and test during the sale.

    Buying a house: radon guide
  • If you are selling

    Testing before you list puts the timing in your hands; disclosure rules differ by state.

    Selling a house: radon guide
  • If you rent, or rent out a home

    A tenant can test; a fix is the owner's to make, and duties differ by state.

    Radon in rental homes

How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.

Lyman County, Products

Testing and mitigation products

Whatever the figures for Lyman County show, only a test tells you about one home.

Lyman County / Next steps

What to do next

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.