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
Locations and reports
Radon Levels in Somerset County, Maine
EPA puts Somerset County in Zone 1, its highest radon zone, and 18.8% of its 85 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
18.8%
18.8 pts below ME
- Somerset
- 18.8%
- Maine
- 37.6%
85 tests, 2008 to 2017
Median result
1.5pCi/L
Below action level
- Somerset
- 1.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
85
14th of 16 by tests
- Somerset
- 85
- Cumberland
- 4,076
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Maine
15 of 16
Lowest quarter
- Somerset
- 18.8%
- York
- 48.4%
By share, of 16 with 30+ tests
Read a result for Somerset County
Starts at Somerset County's median, 1.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.5 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. Somerset County's median reported result, 2008 to 2017.
The data
Somerset County, At a glance
Somerset County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Somerset County in
USGS geologic potential: Moderate across 52% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Somerset County, 2008 to 2017, laboratory
Under 2 pCi/L: 52%2 to 4 pCi/L: 29%4 pCi/L and above: 19%
Of 85 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 44 | 51.8% |
| 2 to 4 pCi/L | 25 | 29.4% |
| 4 pCi/L and above | 16 | 18.8% |
What these figures count
These are the 85 tests reported to CDC for Somerset 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).
Somerset County, Compared
Somerset County radon figures, compared
Calculated by Radon411Somerset County's 85 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.5 pCi/L and a maximum of 14.4 pCi/L, and 18.8% reached 4 pCi/L. Maine as a whole (16 Maine counties, pooled) comes to 37.6%: 18.8 points higher than here.
Among its state's counties it ranks 15th of 16 Maine counties with 30 or more tests for the same period. Statewide for the same period, York County reported the highest share (48.4%) and Penobscot County the lowest (16.4%).
Below the action level, 44 tests (51.8%) came in under 2 pCi/L, against 41.4% statewide, and 25 tests (29.4%) fell between 2 and 4, against 21.0% statewide. CDC's ten-year totals for Somerset County went from 85 tests (2005 to 2014) to 85 (2008 to 2017), the share going from 12.9% to 18.8%.
EPA's 1993 zone map puts Somerset County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 52% of the county's land moderate radon potential.
Next door, the shares run from 16.4% in Penobscot County to 47.7% in Piscataquis County, with Penobscot County below Somerset County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Somerset County, Geology
The ground under Somerset County
PredictedUSGS's geologic map splits Somerset County: 52.3% of its land is moderate radon potential and 2.1% high and 45.6% low. The map puts 52.3% of Somerset County in the area it calls Moose River Lowlands/Central Maine Lowlands/Central Maine Highlands/Coastal Province and 45.5% in Northern Maine Lowlands, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Moose River Lowlands/Central Maine Lowlands/Central Maine Highlands/Coastal Province | Heterogeneous metamorphic and igneous rocks. | Moderate | 11 | 52.3% |
| Northern Maine Lowlands | Clastic and carbonate sedimentary rocks. | Low | 8 | 45.5% |
| Moose River Lowlands/Central Maine Lowlands/Central Maine Highlands/Coastal Province | Granite and high grade metamorphic rocks. | High | 14 | 2.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Somerset County beside the ground around it
Maine as a whole has more high-potential ground than Somerset County: 24.5% of its land, against 2.1% here. Every one of the 6 counties that border it has more high-potential ground, Kennebec County the most at 36.9%.
The map rates the ground, not the air in any home.
Local help
Somerset County, Local resources
Radon testing and mitigation in Somerset County
- Maine Radiation Control ProgramMaine Radiation Control Program, run by Maine Center for Disease Control & Prevention, licenses or certifies radon professionals, and answers questions about testing and mitigation in Maine.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
- See the Maine directoryNo professionals are listed in Maine yet. The state program can point you to registered testers and mitigators.
What Maine's program says
- Phone
- 207-287-5676
- radon.dhhs@maine.gov
- Licensing of radon professionals
Under Maine law, only the owner or occupant of a residence or someone registered with the state to provide these services, may test for radon, install and/or advise on the installation of a radon reduction (mitigation) system.
What it means
Somerset County, Questions
Questions about radon in Somerset County
Are radon levels high in Somerset County?
Over the 2008 to 2017 laboratory totals, 18.8% of the radon tests reported to CDC for Somerset County, Maine were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of 16 Maine counties with 30 or more tests for the same period, 14 reported a higher share; pooled, the state comes to 37.6%.
Which counties border Somerset County?
Somerset County borders 6 counties: Franklin County, Piscataquis County, Penobscot County, Kennebec County, Waldo County and Aroostook County.
Products
Somerset County, Products
Testing a home in Somerset County
In Somerset County, 18.8% of 85 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 37.6% pooled across Maine. In Zone 1 the year-round level in Somerset County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
MonitorAEGTEST
HOUND-3786 rechargeable radon monitor with a 3.5-inch color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Somerset County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Somerset County
Explore
Somerset County, Bordering counties
Counties bordering Somerset County
Calculated by Radon411- Radon levels in Piscataquis CountyEPA zone 1
47.7%at or above 4 pCi/L
Median 3.5 pCi/L · 44 tests · 28.9 points above Somerset County
- Radon levels in Aroostook CountyEPA zone 1
45.1%at or above 4 pCi/L
Median 3.5 pCi/L · 608 tests · 26.3 points above Somerset County
- Radon levels in Waldo CountyEPA zone 2
32.1%at or above 4 pCi/L
Median 2.3 pCi/L · 209 tests · 13.3 points above Somerset County
- Radon levels in Kennebec CountyEPA zone 1
30.3%at or above 4 pCi/L
Median 2.1 pCi/L · 696 tests · 11.5 points above Somerset County
- Radon levels in Franklin CountyEPA zone 1
29.1%at or above 4 pCi/L
Median 1.8 pCi/L · 141 tests · 10.3 points above Somerset County
- Radon levels in Penobscot CountyEPA zone 1
16.4%at or above 4 pCi/L
Median 0.8 pCi/L · 1,491 tests · 2.4 points below Somerset County
Somerset County, Residents
Who lives in Somerset County
The Census Bureau estimates 51,620 residents in Somerset County for July 1, 2025, 1,151 more than in 2020 (+2.3%). That works out to 13 people per square mile of land. Reported testing is thin here: 85 tests over 2008 to 2017, or 1.6 for every 1,000 residents (2025 estimate), where Maine as a whole comes to 8.4.
Census lists no incorporated place in Somerset County: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Somerset County, Homes
Homes in Somerset County
Of Somerset County's 30,009 homes, 74% are detached houses, against 70% across Maine; 16% are mobile homes. Half of its homes were built before 1977, close to Maine's 1976: 33% date from before 1960 and 17% from 2000 or later. Owners live in 77% of the occupied homes (Maine: 74%), so for most households a test and a fix are their own to order.
| Homes | Somerset County | Maine |
|---|---|---|
| Housing units | 30,009 | 746,552 |
| Detached houses | 74% | 70% |
| In buildings of 5 or more | 4% | 9% |
| Mobile homes | 16% | 8% |
| Built before 1960 | 33% | 35% |
| Built since 2000 | 17% | 20% |
| Middle year built | 1977 | 1976 |
| Owner-occupied | 77% | 74% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.