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 Seneca County, New York
EPA puts Seneca County in Zone 1, its highest radon zone, and only 1 radon test from it is on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
21.3%
3.2 pts below NY
- Seneca
- 21.3%
- New York
- 24.5%
319 tests, 2008 to 2017
Median result
2.0pCi/L
Below action level
- Seneca
- 2.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
319
48th of 61 by tests
- Seneca
- 319
- Erie
- 13,822
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 New York
37 of 61
Middle half
- Seneca
- 21.3%
- Chemung
- 52.3%
By share, of 61 with 30+ tests
Read a result for Seneca County
Starts at Seneca County's median, 2.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.0 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Seneca County's median reported result, 2008 to 2017.
The data
Seneca County, At a glance
Seneca County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Seneca County in
USGS geologic potential: High across 81% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Seneca County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2015 | 10.8% |
| 2016 | 60.0% |
| 2017 | 0.0% |
| 2018 | 25.0% |
| 2019 | 0.0% |
| 2020 | 0.0% |
| 2023 | 0.0% |
2023: 0.0%. Across these years the share ran from 0.0% to 60.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 1 test was reported to CDC for Seneca County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Seneca County, Compared
Seneca County radon figures, compared
Calculated by Radon411Seneca County's 319 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.0 pCi/L and a maximum of 36.9 pCi/L, and 21.3% reached 4 pCi/L. New York as a whole (62 New York counties, pooled) comes to 24.5%: 3.2 points higher than here.
The newest figure, in 2023, counts only 1 test (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 319-test figure.
Among its state's counties it ranks 37th of 61 New York counties with 30 or more tests for the same period. Statewide for the same period, Chemung County reported the highest share (52.3%) and Bronx County the lowest (3.2%).
Below the action level, 157 tests (49.2%) came in under 2 pCi/L, against 51.7% statewide, and 94 tests (29.5%) fell between 2 and 4, against 23.7% statewide. The busiest year on file was 2015, with 37 tests reported; the quietest, 2023, had 1.
EPA's 1993 zone map puts Seneca County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 81% of the county's land high radon potential.
Next door, the shares run from 26.9% in Wayne County to 45.9% in Yates County.
CDC also counts 21 tests taken after mitigation in Seneca 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.
Seneca County, State data
New York's own radon test data
MeasuredWhat New York's own agencies publish about radon tests in Seneca County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the New York State Department of Health reports for Seneca County
Indoor air radon testing data (Environmental Public Health Tracker): short-term charcoal canister tests requested through the NYSDOH Radon Program, presented as five-year rolling averages. Period: 2015-2019. The publisher also lists 15 earlier periods.
Share at or above 4 pCi/L
17.9%
Average result
3.6 pCi/L
Tests behind these figures
11.2 tests a year on average
- Every figure is a five-year rolling average: the average result is the rolling average of each year's mean, and the test count is an average per year.
- The data only include tests requested through the NYSDOH Radon Program, and therefore may not capture all radon tests performed in a county.
- The data include both screening tests and post-mitigation tests, as it is not always possible to tell them apart.
- Radon testing by homeowners is optional in New York, so the values may not be representative of every home in the county.
- These figures describe tests reported to the New York State Department of Health in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: New York State Department of Health data, 2015-2019.
Seneca County, Geology
The ground under Seneca County
PredictedMost of the ground under Seneca County is one class on USGS's geologic map: 81.3% of its land is high radon potential, with 18.7% moderate. The map puts 81.3% of Seneca County in the area it calls Allegheny Plateau and 18.7% in Erie-Ontario Lowland. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Allegheny Plateau | Shale, limestone, and sandstone. | High | 12 | 81.3% |
| Erie-Ontario Lowland | Limestone, dolomite, shale, sandstone, and salt deposits. | Moderate | 9 | 18.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Seneca County beside the ground around it
Seneca County has more high-potential ground than New York as a whole: 81.3% of its land against 48.9%. Of the 6 counties that border it, 4 have more high-potential ground, Schuyler County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Seneca County, Local resources
Radon testing and mitigation in Seneca County
- Radon ProgramRadon Program, run by New York State Department of Health, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in New York.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Providing patients with information about how low-cost test kits may be obtained from the Radon Program.
- Compare kits
- Professionals in New York88 professionals are listed in New York.
What New York's program says
- Phone
- 518-402-7556
- radon@health.ny.gov
- Licensing of radon professionals
NYS does not certify or license radon testers.
What it means
Seneca County, Questions
Questions about radon in Seneca County
Are radon levels high in Seneca County?
In 2023, 0.0% of the radon tests reported to CDC for Seneca County, New York were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.9 pCi/L. Of 61 New York counties with 30 or more tests for the same period, 36 reported a higher share; pooled, the state comes to 24.5%.
Which counties border Seneca County?
Seneca County borders 6 counties: Yates County, Cayuga County, Ontario County, Schuyler County, Tompkins County and Wayne County.
Products
Seneca County, Products
Testing a home in Seneca County
In Seneca County, 21.3% of 319 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 24.5% pooled across New York. In Zone 1 the year-round level in Seneca 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
Monitor
RadonScan-Plus USB-powered radon monitor with Wi-Fi
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Seneca County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Seneca County
Explore
Seneca County, Bordering counties
Counties bordering Seneca County
Calculated by Radon411- Radon levels in Yates CountyEPA zone 1
45.9%at or above 4 pCi/L
Median 3.5 pCi/L · 135 tests · 24.6 points above Seneca County
- Radon levels in Schuyler CountyEPA zone 1
38.6%at or above 4 pCi/L
Median 2.5 pCi/L · 236 tests · 17.3 points above Seneca County
- Radon levels in Ontario CountyEPA zone 1
32.8%at or above 4 pCi/L
Median 2.6 pCi/L · 1,448 tests · 11.5 points above Seneca County
- Radon levels in Tompkins CountyEPA zone 1
28.0%at or above 4 pCi/L
Median 2.3 pCi/L · 3,372 tests · 6.7 points above Seneca County
- Radon levels in Cayuga CountyEPA zone 1
27.8%at or above 4 pCi/L
Median 2.1 pCi/L · 726 tests · 6.5 points above Seneca County
- Radon levels in Wayne CountyEPA zone 2
26.9%at or above 4 pCi/L
Median 2.0 pCi/L · 793 tests · 5.6 points above Seneca County
Seneca County, Cities and towns
Cities and towns in Seneca County
About 32,883 people live in Seneca County by the Census Bureau's estimate for July 1, 2025, 562 fewer than in 2020 (−1.7%). That works out to 102 people per square mile of land. Geneva, the largest place on its list (12,552 residents in all), extends beyond Seneca County, so no share of the total is worked out for it. Testing is reported here more often than across the state: CDC's 319 reported tests for 2008 to 2017 come to 9.7 for every 1,000 residents (2025 estimate), against 4.9 for New York.
From Geneva to Lodi, CDC publishes no figure by town: each reads Seneca County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Genevaextends beyond Seneca County | 12,552 | −2.0% | Counted whole |
| Waterloo | 4,674 | −3.8% | 14.2% |
| Interlaken | 606 | −3.0% | 1.8% |
| Ovid | 514 | −5.7% | 1.6% |
| Lodi | 274 | −4.2% | 0.8% |
5 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 Seneca County is counted whole, so it has no share.
Seneca County, Homes
Homes in Seneca County
Of Seneca County's 16,148 homes, 70% are detached houses, against 41% across New York; 10% are mobile homes. Half of its homes were built before 1957, close to New York's 1958: 53% date from before 1960 and 13% from 2000 or later. 72% of occupied homes are lived in by their owner (New York: 54%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Seneca County | New York |
|---|---|---|
| Housing units | 16,148 | 8,539,536 |
| Detached houses | 70% | 41% |
| In buildings of 5 or more | 7% | 34% |
| Mobile homes | 10% | 2% |
| Built before 1960 | 53% | 53% |
| Built since 2000 | 13% | 12% |
| Middle year built | 1957 | 1958 |
| Owner-occupied | 72% | 54% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.