Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Ottawa County, Michigan
EPA puts Ottawa County in Zone 3, its lowest radon zone, and 16.8% of its 2,546 reported radon tests (2008 to 2017, laboratory totals) were 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
Share at 4+ pCi/L
16.8%
10.1 pts below MI
- Ottawa
- 16.8%
- Michigan
- 26.9%
2,546 tests, 2008 to 2017
Median result
1.6pCi/L
Below action level
- Ottawa
- 1.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
2,546
12th of 82 by tests
- Ottawa
- 2,546
- Oakland
- 16,224
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Michigan
40 of 82
Middle half
- Ottawa
- 16.8%
- Lenawee
- 56.7%
By share, of 82 with 30+ tests
Read a result for Ottawa County
Starts at Ottawa County's median, 1.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.6 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Ottawa County's median reported result, 2008 to 2017.
The data
Ottawa County, At a glance
Ottawa County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Ottawa County, 2008 to 2017, laboratory
Under 2 pCi/L: 57%2 to 4 pCi/L: 26%4 pCi/L and above: 17%
Of 2,546 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 1,446 | 56.8% |
| 2 to 4 pCi/L | 671 | 26.4% |
| 4 pCi/L and above | 429 | 16.8% |
What these figures count
These are the 2,546 tests reported to CDC for Ottawa County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Ottawa County, Compared
Ottawa County radon figures, compared
Calculated by Radon411Ottawa County's 2,546 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.6 pCi/L and a maximum of 68.0 pCi/L, and 16.8% reached 4 pCi/L. Michigan as a whole (83 Michigan counties, pooled) comes to 26.9%: 10.1 points higher than here.
Among its state's counties it ranks 40th of 82 Michigan counties with 30 or more tests for the same period. Statewide for the same period, Lenawee County reported the highest share (56.7%) and Muskegon County the lowest (3.2%).
Below the action level, 1,446 tests (56.8%) came in under 2 pCi/L, against 46.4% statewide, and 671 tests (26.4%) fell between 2 and 4, against 26.7% statewide. CDC's ten-year totals for Ottawa County went from 2,527 tests (2005 to 2014) to 2,546 (2008 to 2017), the share going from 15.6% to 16.8%.
EPA's 1993 zone map puts Ottawa County in Zone 3, a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Next door, the shares run from 3.2% in Muskegon County to 18.4% in Allegan County, with Kent County and Muskegon County below Ottawa County.
CDC also counts 147 tests taken after mitigation in Ottawa County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Ottawa County, State data
Michigan's own radon test data
MeasuredWhat Michigan's own agencies publish about radon tests in Ottawa County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Michigan EGLE reports for the ZIP codes in Ottawa County
Michigan EGLE publishes its figures by ZIP code, not by county. These are the 21 ZIP codes that lie wholly or partly in Ottawa County, each with the state's own figures for it. Period: About 10 years to 2026-05-15.
| ZIP code | What the state reports |
|---|---|
| 49315 | 11% greater than 4 pCi/L, median 1.5 pCi/L, 132 tests |
| 49318 | 4 tests, figures not shown |
| 49323 | 0% greater than 4 pCi/L, median 1.2 pCi/L, 32 tests |
| 49330 | 6% greater than 4 pCi/L, median 2.0 pCi/L, 16 tests |
| 49401 | 21% greater than 4 pCi/L, median 2.1 pCi/L, 115 tests |
| 49404 | 9% greater than 4 pCi/L, median 1.3 pCi/L, 35 tests |
| 49415 | 6% greater than 4 pCi/L, median 1.1 pCi/L, 17 tests |
| 49417 | 13% greater than 4 pCi/L, median 1.3 pCi/L, 76 tests |
| 49418 | 20% greater than 4 pCi/L, median 1.9 pCi/L, 207 tests |
| 49423 | 6% greater than 4 pCi/L, median 1.2 pCi/L, 124 tests |
| 49424 | 2% greater than 4 pCi/L, median 1.2 pCi/L, 104 tests |
| 49426 | 10% greater than 4 pCi/L, median 1.5 pCi/L, 195 tests |
| 49428 | 40% greater than 4 pCi/L, median 3.0 pCi/L, 199 tests |
| 49435 | 6% greater than 4 pCi/L, median 1.6 pCi/L, 17 tests |
| 49448 | 0% greater than 4 pCi/L, median 1.1 pCi/L, 12 tests |
| 49451 | 0% greater than 4 pCi/L, median 0.8 pCi/L, 8 tests |
| 49456 | 0% greater than 4 pCi/L, median 0.8 pCi/L, 42 tests |
| 49460 | 3% greater than 4 pCi/L, median 1.7 pCi/L, 33 tests |
| 49464 | 19% greater than 4 pCi/L, median 1.4 pCi/L, 160 tests |
| 49534 | 14% greater than 4 pCi/L, median 1.6 pCi/L, 148 tests |
| 49544 | 16% greater than 4 pCi/L, median 1.6 pCi/L, 45 tests |
- EGLE's figures cover first-time tests only, from organizations willing to provide data.
- EGLE does not publish figures for a ZIP code with fewer than 5 test results.
- EGLE says the map is not intended to decide whether a home should be tested: all homes should be tested.
- ZIP code boundaries are postal delivery areas, not legal or administrative boundaries.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Michigan EGLE data, About 10 years to 2026-05-15.
Ottawa County, Geology
The ground under Ottawa County
PredictedUSGS's geologic map puts all of Ottawa County's mapped land in one class: low radon potential. All of it lies in the area the map calls Lake Michigan Lobe Deposits, to which USGS gives a radon index of 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Lake Michigan Lobe Deposits | Sandy to clayey glacial deposits and some glacial lake deposits. | Low | 8 | 99.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Ottawa County beside the ground around it
Across Michigan 9.6% of the land is rated high; none of Ottawa County's is. Of the 3 counties that border it, 2 have more moderate-potential ground, Kent County the most at 76.4%.
The map rates the ground, not the air in any home.
Local help
Ottawa County, Local resources
Radon testing and mitigation in Ottawa County
- Michigan Indoor Radon ProgramMichigan Indoor Radon Program, run by Michigan Department of Environment, Great Lakes, and Energy, does not license radon professionals, and answers questions about testing and mitigation in Michigan.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in Michigan69 professionals are listed in Michigan.
What Michigan's program says
- Phone
- 800-723-6642
- Radon@Michigan.gov
- Licensing of radon professionals
Michigan does not license or regulate radon testing and mitigation contractors.
What it means
Ottawa County, Questions
Questions about radon in Ottawa County
Are radon levels high in Ottawa County?
Over the 2008 to 2017 laboratory totals, 16.8% of the radon tests reported to CDC for Ottawa County, Michigan were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of 82 Michigan counties with 30 or more tests for the same period, 39 reported a higher share; pooled, the state comes to 26.9%.
Which counties border Ottawa County?
Ottawa County borders 3 counties: Kent County, Muskegon County and Allegan County.
Products
Ottawa County, Products
Testing a home in Ottawa County
In Ottawa County, 16.8% of 2,546 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 26.9% pooled across Michigan. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Ottawa County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Ottawa County, Bordering counties
Counties bordering Ottawa County
Calculated by Radon411- Radon levels in Allegan CountyEPA zone 3
18.4%at or above 4 pCi/L
Median 1.7 pCi/L · 766 tests · 1.6 points above Ottawa County
- Radon levels in Kent CountyEPA zone 2
16.5%at or above 4 pCi/L
Median 1.8 pCi/L · 8,449 tests · 0.3 points below Ottawa County
- Radon levels in Muskegon CountyEPA zone 3
3.2%at or above 4 pCi/L
Median 1.2 pCi/L · 629 tests · 13.6 points below Ottawa County
Ottawa County, Cities and towns
Cities and towns in Ottawa County
The Census Bureau estimates 308,459 residents in Ottawa County for July 1, 2025, 11,566 more than in 2020 (+3.9%). That works out to 547 people per square mile of land. Holland, the largest place on its list (35,372 residents in all), extends beyond Ottawa County, so no share of the total is worked out for it. CDC's 2,546 reported tests for 2008 to 2017 work out to 8.3 per 1,000 residents (2025 estimate), close to Michigan's 11.3.
From Holland to Spring Lake, CDC publishes no figure by town: each reads Ottawa County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Hollandextends beyond Ottawa County | 35,372 | +3.0% | Counted whole |
| Grand Haven | 11,038 | +0.3% | 3.6% |
| Hudsonville | 7,964 | +4.5% | 2.6% |
| Zeeland | 5,637 | −1.8% | 1.8% |
| Coopersville | 4,802 | −0.1% | 1.6% |
| Ferrysburg | 2,955 | +0.1% | 1.0% |
| Spring Lake | 2,504 | −1.4% | 0.8% |
7 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). A place that extends beyond Ottawa County is counted whole, so it has no share.
Ottawa County, Homes
Homes in Ottawa County
Of Ottawa County's 116,173 homes, 70% are detached houses, against 72% across Michigan; 11% are in buildings of five or more homes. Much of Ottawa County is recent building: 29% of its homes have gone up since 2000 and the middle year built is 1987, against 1972 for Michigan. Owners live in 78% of the occupied homes (Michigan: 73%), so for most households a test and a fix are their own to order.
| Homes | Ottawa County | Michigan |
|---|---|---|
| Housing units | 116,173 | 4,599,683 |
| Detached houses | 70% | 72% |
| In buildings of 5 or more | 11% | 13% |
| Mobile homes | 5% | 5% |
| Built before 1960 | 20% | 36% |
| Built since 2000 | 29% | 15% |
| Middle year built | 1987 | 1972 |
| Owner-occupied | 78% | 73% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.