Locations and reports
Radon Levels in San Juan County, Utah
What this means for you
- Your area: EPA rates San Juan County Zone 2, the middle 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 19 radon tests reported to CDC for San Juan County (2023), 52.6% 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.
In 2023, 52.6% of the radon tests reported to CDC for San Juan County, Utah came back at or above the EPA action level of 4 pCi/L, and the median result was 4.0 pCi/L. EPA's Map of Radon Zones places the county in Zone 2, moderate predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
EPA predicts an average indoor of 2 to 4 pCi/L (75 to 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: Moderate across 78% of the county's land area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for San Juan County, 2023
- Tests reported
- 19
- At or above 4 pCi/L
- 52.6%
- Median result
- 4.0 pCi/L
Of 19 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.
| Result band | Tests Calculated by Radon411 | Share Measured |
|---|---|---|
| Under 2 pCi/L | 6 | 31.6% |
| 2 to 4 pCi/L | 3 | 15.8% |
| 4 pCi/L and above | 10 | 52.6% |
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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
San Juan County, In figures
San Juan County in figures
What the published data says about San Juan County, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places San Juan County in Zone 2, moderate predicted potential, as it does 21 other counties of Utah's 29.
Of the 14 bordering counties, EPA places Dolores County, Grand County, Mesa County, Montezuma County, Montrose County and San Miguel County in Zone 1 and Apache County, Coconino County, Emery County, Garfield County, Kane County, Navajo County, San Juan County and Wayne County in Zone 2.
Reported tests
MeasuredCDC has annual figures for San Juan County for 9 years, 2014 to 2023. In 2023, 52.6% of 19 reported tests were at or above 4 pCi/L.
Across those years the share ranged from 0.0% (2019) to 90.0% (2018). Few tests in a year can move it a long way.
Local record
Utah's radon program is the Indoor Radon Program, run by Utah Department of Environmental Quality; its contacts are under Local resources.
The county's largest incorporated places are Blanding, Monticello and Bluff; the figures here cover them as part of the county.
San Juan County, Reported testing
Reported testing over time
Measured| Year | Median reported result | Highest reported result | Share of tests at or above 4 pCi/L |
|---|---|---|---|
| 2014 | 4.6 pCi/L | 32.2 pCi/L | 50.0% |
| 2015 | 2.8 pCi/L | 3.3 pCi/L | 0.0% |
| 2016 | 4.4 pCi/L | 12.7 pCi/L | 50.0% |
| 2017 | 4.3 pCi/L | 10.3 pCi/L | 50.0% |
| 2018 | 9.7 pCi/L | 24.8 pCi/L | 90.0% |
| 2019 | 1.1 pCi/L | 1.9 pCi/L | 0.0% |
| 2020 | No data | No data | No data |
| 2021 | 3.2 pCi/L | 7.3 pCi/L | 16.7% |
| 2022 | 2.7 pCi/L | 10.8 pCi/L | 46.2% |
| 2023 | 4.0 pCi/L | 11.4 pCi/L | 52.6% |
What these figures count
Every percentage here is a share of radon tests reported to CDC for San Juan County in 2023. It is not a share of homes in San Juan County, and it is not a random sample: it counts only the tests people chose to run and that were reported.
The shares and the median are calculated from pre-mitigation tests (19 for 2023). CDC also reports the number of buildings tested (20), a different count, so the two totals are not interchangeable.
San Juan County, Comparison
How San Juan County compares
MeasuredSan Juan 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
Measured2023, highest first. Each county’s own published CDC figure.
- Wayne CountyUT27 tests70.4%
- Montrose CountyCO215 tests55.3%
- San Juan CountyThis page19 tests52.6%
- Garfield CountyUT15 tests40.0%
- Emery CountyUT39 tests38.5%
- San Miguel CountyCO16 tests37.5%
- Montezuma CountyCO72 tests33.3%
- Grand CountyUT46 tests23.9%
- Mesa CountyCO567 tests18.9%
- Kane CountyUT19 tests15.8%
Published for 2023 without this measure: Dolores County, CO.
Median reported result
Measured2023, highest first. Each county’s own published CDC figure.
- Wayne CountyUT27 tests5.5 pCi/L
- Montrose CountyCO215 tests4.5 pCi/L
- San Juan CountyThis page19 tests4.0 pCi/L
- Garfield CountyUT15 tests3.7 pCi/L
- San Miguel CountyCO16 tests3.4 pCi/L
- Montezuma CountyCO72 tests3.0 pCi/L
- Emery CountyUT39 tests2.7 pCi/L
- Mesa CountyCO567 tests2.2 pCi/L
- Grand CountyUT46 tests1.9 pCi/L
- Kane CountyUT19 tests1.8 pCi/L
- Dolores CountyCOTest count not published0.5 pCi/L
Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. San Juan 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 2023: San Juan County, NM; Navajo County, AZ; Apache County, AZ; Coconino County, AZ. Every Utah county’s own figure is in the Utah county table.
CDC publishes this figure only for counties here, so there is no state or national number to compare San Juan County, Utah with.
San Juan County, Bordering counties
Counties bordering San Juan County
Calculated by Radon41114 counties share a boundary with San Juan County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.
- Montezuma CountyCOZone 1: Highest predicted potential
- Dolores CountyCOZone 1: Highest predicted potential
- Wayne CountyUTZone 2: Moderate predicted potential
- San Miguel CountyCOZone 1: Highest predicted potential
- Grand CountyUTZone 1: Highest predicted potential
- Montrose CountyCOZone 1: Highest predicted potential
- Garfield CountyUTZone 2: Moderate predicted potential
- Mesa CountyCOZone 1: Highest predicted potential
- Emery CountyUTZone 2: Moderate predicted potential
- Kane CountyUTZone 2: Moderate predicted potential
- San Juan CountyNMZone 2: Moderate predicted potential
- Navajo CountyAZZone 2: Moderate predicted potential
- Apache CountyAZZone 2: Moderate predicted potential
- Coconino CountyAZZone 2: Moderate predicted potential
San Juan County, Local resources
Local resources in Utah
Who to ask in Utah: the state's radon program, test kits and professionals.
Indoor Radon Program
Utah Department of Environmental Quality
Utah’s radon program answers questions about testing, mitigation and the rules where you live.
- Phone
- (801) 536-0091
- Disclosure when a home is sold or rented
Utah requires that sellers disclose "Hazardous Conditions: Are there any hazardous conditions on the Property such as Radon gas in house or well?"
Test kits
Ask the program whether it has free or discounted kits, or compare kits you can buy.
Radon professionals
No professionals are listed in Utah yet. The state program can point you to registered testers and mitigators.
See the Utah directorySan Juan County, Cities and towns
Cities and towns in San Juan County
The radon figures on this page are for San Juan County as a whole. They do not differ by city or town.
- Blanding
- Monticello
- Bluff
3 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.
San Juan County, Questions
Questions about radon in San Juan County
Common questions8 questions, answered from the figures above
Are radon levels high in San Juan County?
In 2023, 52.6% of the radon tests reported to CDC for San Juan County, Utah were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.0 pCi/L. That is a share of reported tests, not of homes. EPA places San Juan County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 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.
How do I get a radon test in San Juan 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 San Juan County as a service area yet. The Utah 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 stateUtah radon program
Who does radon mitigation in San Juan County?
Radon411 has no certified mitigators listed for Utah yet. 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 Utah requires one.
How radon mitigation worksWhat mitigation costsUtah radon program
What EPA radon zone is San Juan County in?
EPA places San Juan County, Utah in Zone 2, which EPA describes as moderate 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 San Juan 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 San Juan County?
San Juan County borders 14 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 San Juan County, Utah in 2023. They describe tests other people carried out in other buildings, and none of them measures yours.
- How to test a home
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.
- Buying a house: radon guide
If you are buying
Ask for past results and any system's post-mitigation test, and test during the sale.
- Selling a house: radon guide
If you are selling
Testing before you list puts the timing in your hands; disclosure rules differ by state.
- Radon in rental homes
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.
How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.
San Juan County, Products
Testing and mitigation products
Whatever the figures for San Juan County show, only a test tells you about one home.
Testing
- Short-term test kitsPassive detectors exposed for a few days under closed-building conditions, then analyzed by a lab.
- Long-term test kitsDetectors exposed for more than 90 days, for a closer picture of the annual average.
- Continuous monitorsPowered devices that log radon on a repeating cycle, often used for transaction tests.
- Digital detectorsConsumer devices that display a running radon reading without a lab.
- Water radon testsKits for radon dissolved in well water, analyzed by a lab.
Mitigation
- Mitigation fansThe inline fan that keeps a soil depressurization system running, sized by the installer.
- System indicatorsU-tube manometers and fan alarms that show whether a mitigation system is still working.
- Sealing materialsCrack, joint and sump sealing used alongside a mitigation system, not instead of one.
San Juan County / Next steps
What to do next
Learn
Know what radon is
What radon is, how it gets indoors, and why a county zone is not a reading for your home.
Learn about radonTest
Test the building you live in
Short-term or long-term, where the device goes, and closed-house conditions.
How to testFix
Bring a high level down
How a mitigation system works, and the retest that confirms it.
How mitigation worksFind a pro
Hire a certified professional
Measurement and mitigation professionals by state, with their certifications.
Find a professional
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.