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 Putnam County, New York
EPA puts Putnam County in Zone 1, its highest radon zone, and only 9 radon tests from it are 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
24.7%
0.2 pts above NY
- Putnam
- 24.7%
- New York
- 24.5%
1,020 tests, 2008 to 2017
Median result
1.9pCi/L
Below action level
- Putnam
- 1.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,020
24th of 61 by tests
- Putnam
- 1,020
- 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
32 of 61
Middle half
- Putnam
- 24.7%
- Chemung
- 52.3%
By share, of 61 with 30+ tests
Read a result for Putnam County
Starts at Putnam County's median, 1.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.9 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. Putnam County's median reported result, 2008 to 2017.
The data
Putnam County, At a glance
Putnam County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Putnam County in
USGS geologic potential: High across 97% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Putnam County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 25.8% |
| 2015 | 22.2% |
| 2016 | 24.1% |
| 2017 | 13.7% |
| 2018 | 20.0% |
| 2019 | 38.1% |
| 2020 | 17.4% |
| 2022 | 0.0% |
| 2023 | 22.2% |
2023: 22.2%. Across these years the share ran from 0.0% to 38.1%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 9 tests were reported to CDC for Putnam 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).
Putnam County, Compared
Putnam County radon figures, compared
Calculated by Radon411Putnam County's 1,020 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 117.6 pCi/L, and 24.7% reached 4 pCi/L. New York as a whole (62 New York counties, pooled) comes to 24.5%: 0.2 points lower than here.
The newest figure, in 2023, counts only 9 tests (22.2% at or above 4 pCi/L), too few to compare, so this reading uses the 1,020-test figure.
Among its state's counties it ranks 32nd 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, 513 tests (50.3%) came in under 2 pCi/L, against 51.7% statewide, and 255 tests (25.0%) fell between 2 and 4, against 23.7% statewide. The busiest year on file was 2017, with 51 tests reported; the quietest, 2022, had 6.
EPA's 1993 zone map puts Putnam County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 97% of the county's land high radon potential.
Next door, the shares run from 14.6% in Rockland County to 40.8% in Dutchess County, with Westchester County and Rockland County below Putnam County. Over 4 years of annual figures the share rose 12.3 points, from 25.8% in 2014 to 38.1% in 2019; its peak was 38.1% in 2019.
CDC also counts 75 tests taken after mitigation in Putnam County for the same period: tests in homes where a fix was already in.
Putnam CountyNew York, pooled
38.1% % of tests28.0% % of tests
| Year | Tests | Putnam County, at or above 4 pCi/L | New York, pooled |
|---|---|---|---|
| 2014 | 31 | 25.8% | 16.6% |
| 2017 | 51 | 13.7% | 31.6% |
| 2018 | 45 | 20.0% | 26.9% |
| 2019 | 42 | 38.1% | 28.0% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Putnam County, State data
New York's own radon test data
MeasuredWhat New York's own agencies publish about radon tests in Putnam 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 Putnam 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
24.3%
Average result
3.6 pCi/L
Tests behind these figures
37.8 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.
Putnam County, Geology
The ground under Putnam County
PredictedMost of the ground under Putnam County is one class on USGS's geologic map: 96.6% of its land is high radon potential, with 3.4% moderate. The map puts 87.5% of Putnam County in the area it calls Hudson Highlands and 9.2% in New England-Taconic Mountains, with one smaller area beside them. USGS gives the first a radon index of 13 and the second 12, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Hudson Highlands | Amphibolitic gneiss, quartz-poor gneisses, and marbles. | High | 13 | 87.5% |
| New England-Taconic Mountains | Slate, phyllite, graywacke, and limestone. | High | 12 | 9.2% |
| Manhattan Prong | Gneiss, amphibolite, quartzite, marble, schist, diorite. | Moderate | 9 | 3.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Putnam County beside the ground around it
Putnam County has more high-potential ground than New York as a whole: 96.6% of its land against 48.9%. Of the 5 counties that border it, 2 have more high-potential ground, Orange County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Putnam County, Local resources
Radon testing and mitigation in Putnam 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
Putnam County, Questions
Questions about radon in Putnam County
Are radon levels high in Putnam County?
In 2023, 22.2% of the radon tests reported to CDC for Putnam County, New York were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. Of 61 New York counties with 30 or more tests for the same period, 31 reported a higher share; pooled, the state comes to 24.5%.
Which counties border Putnam County?
Putnam County borders 5 counties: Westchester County, NY, Rockland County, NY, Fairfield County, CT, Dutchess County, NY and Orange County, NY.
Products
Putnam County, Products
Testing a home in Putnam County
In Putnam County, 24.7% of 1,020 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 Putnam 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
MonitorKidde
Radon Detector (RAB) battery digital radon detector with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 12 hours
Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Putnam County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Putnam County
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Putnam County, Bordering counties
Counties bordering Putnam County
Calculated by Radon411- Radon levels in Dutchess County, NYEPA zone 1
40.8%at or above 4 pCi/L
Median 3.0 pCi/L · 2,133 tests · 16.1 points above Putnam County
- Radon levels in Orange County, NYEPA zone 1
30.6%at or above 4 pCi/L
Median 2.2 pCi/L · 2,790 tests · 5.9 points above Putnam County
- Radon levels in Fairfield County, CTEPA zone 1
27.4%at or above 4 pCi/L
Median 2.1 pCi/L · 7,638 tests · 2.7 points above Putnam County
- Radon levels in Westchester County, NYEPA zone 3
16.3%at or above 4 pCi/L
Median 1.5 pCi/L · 3,463 tests · 8.4 points below Putnam County
- Radon levels in Rockland County, NYEPA zone 3
14.6%at or above 4 pCi/L
Median 1.5 pCi/L · 824 tests · 10.1 points below Putnam County
Putnam County, Cities and towns
Cities and towns in Putnam County
The Census Bureau estimates 99,028 residents in Putnam County for July 1, 2025, 1,392 more than in 2020 (+1.4%). That works out to 430 people per square mile of land. No town dominates: Brewster, the largest, has 2,509 residents, 2.5% of the total. Together its 3 incorporated places hold 5.2% of those residents; the other 94.8% live outside any of them. Testing is reported here more often than across the state: CDC's 1,020 reported tests for 2008 to 2017 come to 10.3 for every 1,000 residents (2025 estimate), against 4.9 for New York.
From Brewster to Nelsonville, CDC publishes no figure by town: each reads Putnam County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Brewster | 2,509 | +0.1% | 2.5% |
| Cold Spring | 1,998 | +0.7% | 2.0% |
| Nelsonville | 635 | +1.6% | 0.6% |
3 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).
Putnam County, Homes
Homes in Putnam County
Putnam County is a place of houses on their own lots: 78% of its 38,369 homes are detached single-family houses, against 41% across New York. Much of Putnam County is recent building: 11% of its homes have gone up since 2000 and the middle year built is 1968, against 1958 for New York. Owners live in 83% of the occupied homes (New York: 54%), so for most households a test and a fix are their own to order.
| Homes | Putnam County | New York |
|---|---|---|
| Housing units | 38,369 | 8,539,536 |
| Detached houses | 78% | 41% |
| In buildings of 5 or more | 7% | 34% |
| Mobile homes | 1% | 2% |
| Built before 1960 | 40% | 53% |
| Built since 2000 | 11% | 12% |
| Middle year built | 1968 | 1958 |
| Owner-occupied | 83% | 54% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.