Locations and reports
Radon Levels in Macon County, Illinois
What this means for you
- Your area: EPA rates Macon 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 1,251 radon tests reported to CDC for Macon County (2017), 38.8% 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 2017, 38.8% of the radon tests reported to CDC for Macon County, Illinois came back at or above the EPA action level of 4 pCi/L, and the median result was 3.1 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 100% of the county's land area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Macon County, 2017
- Tests reported
- 1,251
- At or above 4 pCi/L
- 38.8%
- Median result
- 3.1 pCi/L
Of 1,251 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 | 345 | 27.6% |
| 2 to 4 pCi/L | 420 | 33.6% |
| 4 pCi/L and above | 486 | 38.8% |
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: 2017. Measured data period: 2005 to 2017 (every CDC figure on file).
Macon County, In figures
Macon County in figures
What the published data says about Macon County, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places Macon County in Zone 1, highest predicted potential, as it does 55 other counties of Illinois's 102.
Of the 7 bordering counties, EPA places De Witt County, Logan County, Moultrie County, Piatt County and Sangamon County in Zone 1 and Christian County and Shelby County in Zone 2.
Reported tests
MeasuredCDC has annual figures for Macon County for 3 years, 2014 to 2017. In 2017, 38.8% of 1,251 reported tests were at or above 4 pCi/L.
Across those years the share ranged from 37.8% (2015) to 42.3% (2014). Few tests in a year can move it a long way.
Local record
Illinois's radon program is the IEMA-OHS Radon Program, run by Illinois Emergency Management Agency and Office of Homeland Security; its contacts are under Local resources.
The county's largest incorporated places are Decatur, Mount Zion and Forsyth; the figures here cover them as part of the county.
Macon County, Reported testing
Reported testing over time
MeasuredNo figures are published for 2016. The axis keeps the space for the missing year and the line is not drawn across it.
| Year | Median reported result | Highest reported result | Share of tests at or above 4 pCi/L |
|---|---|---|---|
| 2014 | 3.2 pCi/L | 37.1 pCi/L | 42.3% |
| 2015 | 3.0 pCi/L | 21.4 pCi/L | 37.8% |
| 2017 | 3.1 pCi/L | 23.1 pCi/L | 38.8% |
What these figures count
Every percentage here is a share of radon tests reported to CDC for Macon County in 2017. It is not a share of homes in Macon 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 (1,251 for 2017). CDC also reports the number of buildings tested (417), a different count, so the two totals are not interchangeable.
Macon County, Comparison
How Macon County compares
MeasuredMacon 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
Measured2017, highest first. Each county’s own published CDC figure.
- Shelby CountyIL21 tests71.4%
- De Witt CountyIL126 tests57.1%
- Piatt CountyIL279 tests54.8%
- Moultrie CountyIL45 tests46.7%
- Logan CountyIL72 tests45.8%
- Sangamon CountyIL3,378 tests43.7%
- Christian CountyIL213 tests42.3%
- Macon CountyThis page1,251 tests38.8%
Median reported result
Measured2017, highest first. Each county’s own published CDC figure.
- De Witt CountyIL126 tests5.2 pCi/L
- Shelby CountyIL21 tests5.2 pCi/L
- Piatt CountyIL279 tests4.3 pCi/L
- Sangamon CountyIL3,378 tests3.7 pCi/L
- Christian CountyIL213 tests3.5 pCi/L
- Logan CountyIL72 tests3.4 pCi/L
- Moultrie CountyIL45 tests3.3 pCi/L
- Macon CountyThis page1,251 tests3.1 pCi/L
Each figure is that county’s own published CDC figure for 2017, counting radon tests reported to CDC, not homes. Macon 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. Every Illinois county’s own figure is in the Illinois county table.
CDC publishes this figure only for counties here, so there is no state or national number to compare Macon County, Illinois with.
Macon County, Bordering counties
Counties bordering Macon County
Calculated by Radon4117 counties share a boundary with Macon 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.
- Piatt CountyILZone 1: Highest predicted potential
- De Witt CountyILZone 1: Highest predicted potential
- Moultrie CountyILZone 1: Highest predicted potential
- Christian CountyILZone 2: Moderate predicted potential
- Logan CountyILZone 1: Highest predicted potential
- Shelby CountyILZone 2: Moderate predicted potential
- Sangamon CountyILZone 1: Highest predicted potential
Macon County, Local resources
Local resources in Illinois
Who to ask in Illinois: the state's radon program, test kits and professionals.
IEMA-OHS Radon Program
Illinois Emergency Management Agency and Office of Homeland Security
Illinois’s radon program answers questions about testing, mitigation and the rules where you live.
- Phone
- (800) 325-1245
- Licensing of radon professionals
The Agency also licenses and regulates the individuals who provide radon measurement and mitigation to the public.
- Disclosure when a home is sold or rented
Illinois Radon Awareness Act - This is the legislation that requires the seller to provide to the buyer of any interest in residential real property the IEMA-OHS pamphlet entitled "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards.
Test kits
Ask the program whether it has free or discounted kits, or compare kits you can buy.
Radon professionals
387 professionals are listed in Illinois.
Professionals in IllinoisMacon County, Cities and towns
Cities and towns in Macon County
The radon figures on this page are for Macon County as a whole. They do not differ by city or town.
- Decatur
- Mount Zion
- Forsyth
- Maroa
- Harristown
- Long Creek
- Macon
- Blue Mound
- Warrensburg
- Argenta
- Oreana
- Niantic
12 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.
Macon County, Questions
Questions about radon in Macon County
Common questions8 questions, answered from the figures above
Are radon levels high in Macon County?
In 2017, 38.8% of the radon tests reported to CDC for Macon County, Illinois were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.1 pCi/L. That is a share of reported tests, not of homes. EPA places Macon 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.
How do I get a radon test in Macon 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 Macon County as a service area yet. The Illinois 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 stateIllinois radon program
Who does radon mitigation in Macon County?
No listed mitigator names Macon County as a service area yet; the Illinois directory lists 387 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 Illinois requires one.
How radon mitigation worksWhat mitigation costsMitigators in Illinois
What EPA radon zone is Macon County in?
EPA places Macon County, Illinois 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 Macon 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 Macon County?
Macon County borders 7 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 Macon County, Illinois in 2017. 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.
Macon County, Products
Testing and mitigation products
Whatever the figures for Macon 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.
Macon 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.