Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
Locations and reports
Radon Levels in Kent County, Delaware
EPA puts Kent County in Zone 3, its lowest radon zone, and 16.9% of its 1,516 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
16.9%
0.2 pts above DE
- Kent
- 16.9%
- Delaware
- 16.7%
1,516 tests, 2008 to 2017
Median result
1.6pCi/L
Below action level
- Kent
- 1.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,516
2nd of 3 by tests
- Kent
- 1,516
- New Castle
- 10,247
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 Delaware
2 of 3
Middle half
- Kent
- 16.9%
- New Castle
- 17.0%
By share, of 3 with 30+ tests
Read a result for Kent County
Starts at Kent 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. Kent County's median reported result, 2008 to 2017.
The data
Kent County, At a glance
Kent 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 Kent County, 2008 to 2017, laboratory
Under 2 pCi/L: 57%2 to 4 pCi/L: 26%4 pCi/L and above: 17%
Of 1,516 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 866 | 57.1% |
| 2 to 4 pCi/L | 394 | 26.0% |
| 4 pCi/L and above | 256 | 16.9% |
What these figures count
These are the 1,516 tests reported to CDC for Kent 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).
Kent County, Compared
Kent County radon figures, compared
Calculated by Radon411Kent County's 1,516 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.6 pCi/L and a maximum of 25.1 pCi/L, and 16.9% reached 4 pCi/L. Delaware as a whole (3 Delaware counties, pooled) comes to 16.7%: 0.2 points lower than here.
Among its state's counties it ranks 2nd of 3 Delaware counties with 30 or more tests for the same period. Statewide for the same period, New Castle County reported the highest share (17.0%) and Sussex County the lowest (10.4%).
Below the action level, 866 tests (57.1%) came in under 2 pCi/L, against 55.3% statewide, and 394 tests (26.0%) fell between 2 and 4, against 28.0% statewide. CDC's ten-year totals for Kent County went from 1,270 tests (2005 to 2014) to 1,516 (2008 to 2017), the share going from 15.0% to 16.9%.
EPA's 1993 zone map puts Kent 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 10.4% in Sussex County to 52.6% in Kent County, MD, with Sussex County below Kent County.
CDC also counts 41 tests taken after mitigation in Kent 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.
Kent County, Geology
The ground under Kent County
PredictedUSGS's geologic map puts all of Kent County's mapped land in one class: low radon potential. All of it lies in the area the map calls Coastal Plain, to which USGS gives a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Coastal Plain | Cretaceous, Tertiary and Quaternary quartzitic fluvial and marine sediments. | Low | 7 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Kent County beside the ground around it
Across Delaware 14.0% of the land is rated moderate; none of Kent County's is. Of the 5 counties that border it, 1 has more moderate-potential ground, New Castle County the most at 63.8%.
The map rates the ground, not the air in any home.
Local help
Kent County, Local resources
Radon testing and mitigation in Kent County
Listed radon businesses with an address in Kent County:
- Delaware Division of Public Health Radon OfficeDelaware Division of Public Health Radon Office, run by Delaware Division of Public Health, offers free or discounted test kits, and answers questions about testing and mitigation in Delaware.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Delaware Residents click HERE for your free radon test kit.
- Compare kits
- Professionals in Delaware2 professionals are listed in Delaware.
Listed radon professionals by town: Dover
What Delaware's program says
- Phone
- 1-800-464-HELP
What it means
Kent County, Questions
Questions about radon in Kent County
Are radon levels high in Kent County?
Over the 2008 to 2017 laboratory totals, 16.9% of the radon tests reported to CDC for Kent County, Delaware were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of 3 Delaware counties with 30 or more tests for the same period, 1 reported a higher share; pooled, the state comes to 16.7%.
Which counties border Kent County?
Kent County borders 5 counties: Caroline County, MD, Queen Anne's County, MD, Sussex County, DE, Kent County, MD and New Castle County, DE.
Products
Kent County, Products
Testing a home in Kent County
In Kent County, 16.9% of 1,516 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 16.7% pooled across Delaware. 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 Kent County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Monitor
Corentium Home 2 battery digital radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Screen, app
Method: Alpha spectrometry
Readings: Every 60 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Kent County, Bordering counties
Counties bordering Kent County
Calculated by Radon411- Radon levels in Kent County, MDEPA zone 3
52.6%at or above 4 pCi/L
Median 4.4 pCi/L · 57 tests · 35.7 points above Kent County
- Radon levels in New Castle County, DEEPA zone 2
17.0%at or above 4 pCi/L
Median 1.8 pCi/L · 10,247 tests · 0.1 points above Kent County
- Radon levels in Queen Anne's County, MDEPA zone 3
16.9%at or above 4 pCi/L
Median 1.3 pCi/L · 65 tests · 0.0 points above Kent County
- Radon levels in Sussex County, DEEPA zone 3
10.4%at or above 4 pCi/L
Median 1.0 pCi/L · 451 tests · 6.5 points below Kent County
- Radon levels in Caroline County, MDEPA zone 3
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 12 tests · 16.9 points below Kent County
Kent County, Cities and towns
Cities and towns in Kent County
Kent County is growing: the Census Bureau puts it at 194,786 residents on July 1, 2025, up 6.8% from 182,322 in 2020. That works out to 332 people per square mile of land. Its largest town, Dover, has 40,592 residents, 20.8% of the total. CDC's 1,516 reported tests for 2008 to 2017 work out to 7.8 per 1,000 residents (2025 estimate), close to Delaware's 11.5.
From Dover to Hartly, CDC publishes no figure by town: each reads Kent County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Dover | 40,592 | +3.0% | 20.8% |
| Milfordextends beyond Kent County | 14,723 | +30.3% | Counted whole |
| Smyrnaextends beyond Kent County | 13,340 | +2.9% | Counted whole |
| Claytonextends beyond Kent County | 4,527 | +13.4% | Counted whole |
| Camden | 4,176 | +12.2% | 2.1% |
| Harrington | 3,974 | +4.9% | 2.0% |
| Cheswold | 2,653 | +36.9% | 1.4% |
| Wyoming | 1,865 | +9.3% | 1.0% |
| Felton | 1,386 | +5.4% | 0.7% |
| Frederica | 1,155 | +5.8% | 0.6% |
| Houston | 405 | +4.7% | 0.2% |
| Magnolia | 291 | +3.9% | 0.1% |
- Bowers
- Kenton
- Woodside
- Little Creek
- Leipsic
- Viola
- Farmington
- Hartly
20 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Kent County is counted whole, so it has no share.
Kent County, Homes
Homes in Kent County
Of Kent County's 74,997 homes, 65% are detached houses, against 59% across Delaware; 12% are in buildings of five or more homes. Half of its homes were built before 1993, close to Delaware's 1986: 15% date from before 1960 and 40% from 2000 or later. 71% of occupied homes are lived in by their owner (Delaware: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Kent County | Delaware |
|---|---|---|
| Housing units | 74,997 | 457,958 |
| Detached houses | 65% | 59% |
| In buildings of 5 or more | 12% | 14% |
| Mobile homes | 11% | 7% |
| Built before 1960 | 15% | 21% |
| Built since 2000 | 40% | 32% |
| Middle year built | 1993 | 1986 |
| Owner-occupied | 71% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.