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Radon in Ames, Iowa

EPA puts Story County, where Ames is, in Zone 1, its highest radon zone, and high results are common there: 59.9% of the 2,568 radon tests reported to CDC (2008 to 2017, laboratory totals) came back at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    59.9%

    1.4 pts above IA

    Story
    59.9%
    Iowa
    58.5%

    Story, 65th of 99 in IA, 2008 to 2017

  • Median result

    5.0pCi/L

    Action level reached

    Story
    5.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of Story's tests, 2008 to 2017

  • Nearest county

    68.7%

    Boone, 16 miles

    Boone
    68.7%
    Story
    59.9%

    1,134 tests, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    Story, where Ames is

  • Tests reported

    2,568

    In Story

    Story
    2,568
    Boone
    1,134

    Reported to CDC before any fix, 2008 to 2017

Read a result for Ames

Starts at Story County's median, 5.0 pCi/L

5.0pCi/L

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

EPA’s reading of 5.0 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. Story County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Ames, What is published

What is published for Ames

Information:

Every figure for Ames is a county's

Radon data is published by county, not by city, so for Ames it is Story County's: its EPA zone (Zone 1) and the 2,568 tests reported to CDC for 2008 to 2017, laboratory. Only a test tells you about one home.

Ames covers 27.6 square miles of land, all of it in Story County. About 68,220 people live there, 2,472 to the square mile.

Ames, Counties

The county Ames lies in

Measured

Story County's EPA zone and the figures CDC publishes for it, 2008 to 2017, laboratory.

Story CountyZone 1Highest predicted potential

59.9%
Reported tests at or above 4 pCi/L
5.0 pCi/L
Median reported result
2,568 tests
Tests reported to CDC
None
Yearly figures on file

Story County ranks 65th of 99 Iowa counties with 30 or more tests for that period, 1.4 points above the 58.5% pooled across Iowa's counties, 24.2 points above the national pool of 35.7%.

The counties nearest Ames with a CDC figure for 2008 to 2017, laboratory, measured from the middle of the city: Boone County (16 miles, 68.7% of 1,134 tests), Polk County (24 miles, 64.4% of 10,945 tests) and Hamilton County (25 miles, 64.3% of 252 tests). Across the 8 nearest, the share at or above 4 pCi/L runs from 58.5% to 73.3%; the farthest of them, Greene County, is 40 miles away at 71.3%.

The directory lists 2 businesses with an address in Ames, 2 for testing and 2 for mitigation. Iowa's other cities with a page of their own: Des Moines, Sioux City, Iowa City and Waterloo.

The counties around Ames

By distance from the middle of Ames; counties with 30 or more tests.

Nearest counties to Ames with 30 or more tests
CountyDistanceTestsAt or above 4 pCi/LMedian
Boone County16 mi1,13468.7%6.0 pCi/L
Polk County24 mi10,94564.4%5.6 pCi/L
Hamilton County25 mi25264.3%5.5 pCi/L
Hardin County32 mi34962.8%5.6 pCi/L
Dallas County32 mi2,35258.5%4.9 pCi/L
Marshall County32 mi57070.2%8.2 pCi/L
Jasper County38 mi74673.3%8.2 pCi/L
Greene County40 mi14371.3%6.2 pCi/L

Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2008 to 2017, laboratory.

Ames, Geology

The ground under Ames

Predicted

USGS's geologic map puts all of Ames' mapped land in one class: high radon potential. All of it lies in the area the map calls Des Moines Lobe, to which USGS gives a radon index of 12, in the high band (12 to 17).

USGS's geologic areas under Ames
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Des Moines LobeCalcareous loamy till derived from shale, limestone, dolomite, sandstone.High12100%

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

Ames beside its county and Iowa

All of Ames, like all of Story County, is rated high. On high-potential ground Ames is close to Iowa as a whole: 100% of its land against 98.8%.

Share of land by USGS radon potential: Ames, the county it lies in and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
AmesBy countyNoneNone100%
Story CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Ames, Homes

Homes in Ames

Ames has 27,706 homes, and many share a building: 43% are in buildings of five or more, 40% are detached houses, against 53% across Story County. Much of Ames is recent building: 37% of its homes have gone up since 2000 and the middle year built is 1991, against 1983 for Story County. Most occupied homes here are rented: owners live in 43% (Story County: 56%). A tenant can run a test; a fix is the landlord's to make.

Homes in Ames, Story County, Iowa, 2019 to 2023
HomesAmesStory CountyIowa
Housing units27,70641,6421,427,175
Detached houses40%53%72%
In buildings of 5 or more43%31%14%
Mobile homes3%4%3%
Built before 196020%24%39%
Built since 200037%31%21%
Middle year built199119831971
Owner-occupied43%56%72%

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

Local help

Ames, Professionals

Radon professionals listed in Ames

Businesses whose listed city is Ames, from the state registries and listings in the Radon411 directory, with the same business and certification status the directory shows.

2 listings with Ames as the city. See radon mitigation and testing in Ames, or all radon professionals in Iowa.

Ames, Local resources

Local resources for Ames

Who to ask in Iowa: its radon program, test kits and professionals.

The program's own words on licensing and disclosure are on the Iowa page.

What it means

Ames, Questions

Questions about radon in Ames

What radon zone is Ames in?

EPA's map puts Story County, and with it Ames, in Zone 1, the map's highest class: a predicted county average above 4 pCi/L.

What are radon levels in Ames?

59.9% of the 2,568 tests reported from Story County for 2008 to 2017 (laboratory totals) were at or above 4 pCi/L, the level at which EPA says to fix a home: high results are ordinary around Ames. The median reported result was 5.0 pCi/L.

Should I test my home in Ames?

Yes. About 1,538 of the 2,568 tests reported from Story County were at or above 4 pCi/L. That is about what Iowa as a whole reports (58.5%), and ranks Story County 65th of the 99 Iowa counties with 30 or more tests. No map says which homes those are. How to test a home.

What ground is Ames built on, as far as radon goes?

USGS's geologic map puts all of Ames on one named area, "Des Moines Lobe", rated high for radon potential, radon index 12.

Is radon higher in the counties around Ames?

Some are and some are not. Against Story County's 59.9%, 7 of the 8 nearest counties with a figure report more and 1 less, from Dallas County (58.5%, 32 miles off) to Jasper County (73.3%, 38 miles off).

Who tests for or fixes radon in Ames?

Radon411's directory has 2 businesses with an address in Ames, both listed for testing and for mitigation. Every entry names the public list it was taken from. Radon professionals in Ames.

The answers use the published figures of Story County, the county Ames lies in.

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