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Radon Levels in Rockland County, New York

EPA puts Rockland County in Zone 3, its lowest radon zone, and only 15 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

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  • Share at 4+ pCi/L

    14.6%

    9.9 pts below NY

    Rockland
    14.6%
    New York
    24.5%

    824 tests, 2008 to 2017

  • Median result

    1.5pCi/L

    Below action level

    Rockland
    1.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    824

    29th of 61 by tests

    Rockland
    824
    Erie
    13,822

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

  • Rank in New York

    49 of 61

    Lowest quarter

    Rockland
    14.6%
    Chemung
    52.3%

    By share, of 61 with 30+ tests

Read a result for Rockland County

Starts at Rockland County's median, 1.5 pCi/L

1.5pCi/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

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Rockland County's median reported result, 2008 to 2017.

Interpret this reading

The data

Rockland County, At a glance

Rockland County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Rockland County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 56% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Rockland County, 2023

Share of reported tests at or above 4 pCi/L, by year, Rockland County
Share of reported tests at or above 4 pCi/L, by year, Rockland County
YearShare of reported tests at or above 4 pCi/L
201410.2%
20152.6%
201613.0%
201716.3%
201810.4%
20195.8%
202010.3%
202110.2%
20220.0%
20230.0%

2023: 0.0%. Across these years the share ran from 0.0% to 16.3%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 15 tests were reported to CDC for Rockland 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).

How to read these figures

Rockland County, Compared

Rockland County radon figures, compared

Calculated by Radon411

Rockland County reports fewer high tests than New York overall. 14.6% of its 824 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 9.9 points below the 24.5% pooled from 62 New York counties.

The newest figure, in 2023, counts only 15 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 824-test figure.

Ordered from highest share down, it comes 49th of 61 New York counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Rockland County sits 21.1 points below it.

Next door, the shares run from 16.3% in Westchester County to 30.6% in Orange County. Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 14.6% share point the same way here.

Half the tests came in under 1.5 pCi/L and half over it; the single highest reached 33.6 pCi/L. The rest split 61.8% under 2 pCi/L and 23.7% from 2 to 4 (New York: 51.7% and 23.7%). Year by year, 2014 opened at 10.2% and 2021 closed at 10.2% (about level), with 2017 the high at 16.3%.

The busiest year on file was 2016, with 100 tests reported; the quietest, 2022, had 3.

Share of reported tests at or above 4 pCi/L by year, Rockland County against New York2014 to 2021, years with 30 or more tests: Rockland County 10.2% to 10.2%, the state's pooled share 18.9% in 2021.
Rockland CountyNew York, pooled
Share of reported tests at or above 4 pCi/L by year, Rockland County against New York: data table
YearTestsRockland County, at or above 4 pCi/LNew York, pooled
20145910.2%16.6%
2015762.6%21.4%
201610013.0%20.4%
20174916.3%31.6%
20184810.4%26.9%
2019865.8%28.0%
20208710.3%22.7%
20214910.2%18.9%
Rockland County against New York, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Rockland County
Rockland County82414.6%1.5 pCi/LThis county
New York, pooled62 counties, pooled97,14524.5%Not pooled+9.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+21.1 points
Chemung Countyhighest in the state1,53752.3%4.3 pCi/L+37.7 points
Bronx Countylowest in the state1853.2%0.5 pCi/L−11.4 points
Orange County, NYborders it2,79030.6%2.2 pCi/L+16.0 points
Putnam County, NYborders it1,02024.7%1.9 pCi/L+10.1 points
Westchester County, NYborders it3,46316.3%1.5 pCi/L+1.7 points
Where Rockland County's reported results fell, 2008 to 2017, laboratory, beside New York and the United States
ResultRockland County testsRockland County shareNew York shareU.S. shareAgainst New York
Under 2 pCi/L50961.8%51.7%39.6%+10.1 points
2 to 4 pCi/L19523.7%23.7%24.7%Level
4 pCi/L and above12014.6%24.5%35.7%−9.9 points
Rockland County ranked among the 61 New York counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Warren County44 of 612,55315.7%1.6 pCi/L
Albany County45 of 612,74015.7%1.4 pCi/L
Oswego County46 of 6177815.2%1.4 pCi/L
Monroe County47 of 617,11315.1%1.8 pCi/L
Montgomery County48 of 6125214.7%1.6 pCi/L
Rockland County49 of 6182414.6%1.5 pCi/L
Niagara County50 of 612,01614.3%1.6 pCi/L
St. Lawrence County51 of 6115113.2%1.2 pCi/L
Fulton County52 of 6133411.7%1.2 pCi/L
Richmond County53 of 6130011.7%1.0 pCi/L
Essex County54 of 6113310.5%1.3 pCi/L
Rockland County radon tests by year, against New York's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNew York, pooledChange from the row before
2023150.0%1.0 pCi/L3.5 pCi/L32.0%Level
202230.0%0.9 pCi/L0.9 pCi/L22.4%−10.2 points
20214910.2%1.3 pCi/L7.7 pCi/L18.9%−0.1 points
20208710.3%1.2 pCi/L10.5 pCi/L22.7%+4.5 points
2019865.8%1.4 pCi/L15.1 pCi/L28.0%−4.6 points
20184810.4%1.8 pCi/L5.6 pCi/L26.9%−5.9 points
20174916.3%1.8 pCi/L6.9 pCi/L31.6%+3.3 points
201610013.0%1.6 pCi/L16.7 pCi/L20.4%+10.4 points
2015762.6%1.3 pCi/L10.3 pCi/L21.4%−7.6 points
20145910.2%1.4 pCi/L12.5 pCi/L16.6%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Rockland County, State data

New York's own radon test data

Measured

What New York's own agencies publish about radon tests in Rockland 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 Rockland 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

9%

Average result

2.0 pCi/L

Tests behind these figures

73.6 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.

Rockland County, Geology

The ground under Rockland County

Predicted

USGS's geologic map splits Rockland County: 56.1% of its land is low radon potential and 35.8% high and 8.1% moderate. The map puts 55.9% of Rockland County in the area it calls Triassic Lowland and 35.7% in Hudson Highlands, with one smaller area beside them. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 13, in the high band (12 to 17).

USGS's geologic areas under Rockland County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Triassic LowlandFluvial quartz sands, minor siltstones and shales, and Jurassic basalt and diabase.Low855.9%
Hudson HighlandsAmphibolitic gneiss, quartz-poor gneisses, and marbles.High1335.7%
Manhattan ProngGneiss, amphibolite, quartzite, marble, schist, diorite.Moderate98.1%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Rockland County beside the ground around it

New York as a whole has more high-potential ground than Rockland County: 48.9% of its land, against 35.8% here. Of the 5 counties that border it, 3 have more high-potential ground, Orange County the most at 100%.

Share of land by USGS radon potential: Rockland County, the 5 counties bordering it and New York
AreaEPA zoneLow potentialModerate potentialHigh potential
Rockland CountyZone 356.1%8.1%35.8%
Westchester CountyZone 3None84.5%15.2%
Bergen County, NJZone 297.4%None2.6%
Passaic County, NJZone 235.7%None64.3%
Orange CountyZone 1NoneNone100%
Putnam CountyZone 1None3.4%96.6%
New York62 counties, pooled by land areaVaries22.0%28.2%48.9%

The map rates the ground, not the air in any home.

Local help

Rockland County, Local resources

Radon testing and mitigation in Rockland County

What New York's program says
Phone
518-402-7556
Email
radon@health.ny.gov
Licensing of radon professionals
NYS does not certify or license radon testers.

What it means

Rockland County, Questions

Questions about radon in Rockland County

Are radon levels high in Rockland County?

In 2023, 0.0% of the radon tests reported to CDC for Rockland County, New York were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 61 New York counties with 30 or more tests for the same period, 48 reported a higher share; pooled, the state comes to 24.5%.

Which counties border Rockland County?

Rockland County borders 5 counties: Westchester County, NY, Bergen County, NJ, Passaic County, NJ, Orange County, NY and Putnam County, NY.

Products

Rockland County, Products

Testing a home in Rockland County

In Rockland County, 14.6% of 824 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 24.5% pooled across New York. 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 Rockland County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Rockland County homes, compared

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Rockland County, Bordering counties

Counties bordering Rockland County

Calculated by Radon411

Rockland County, Cities and towns

Cities and towns in Rockland County

Rockland County is growing: the Census Bureau puts it at 357,397 residents on July 1, 2025, up 5.9% from 337,429 in 2020. Packed into its land, that is 2,061 people per square mile. No town dominates: Spring Valley, the largest, has 34,482 residents, 9.6% of the total. Reported testing is thin here: 824 tests over 2008 to 2017, or 2.3 for every 1,000 residents (2025 estimate), where New York as a whole comes to 4.9.

From Spring Valley to South Nyack, CDC publishes no figure by town: each reads Rockland County's.

The 12 largest cities and towns in Rockland County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Spring Valley34,482+4.6%9.6%
Haverstraw12,791+4.3%3.6%
Suffern11,796+3.2%3.3%
West Haverstraw11,025+3.3%3.1%
Chestnut Ridge10,987+4.9%3.1%
Airmont10,634+5.7%3.0%
New Square10,214+5.3%2.9%
Nyack7,511+3.9%2.1%
Wesley Hills6,477+5.5%1.8%
Kaser6,121+11.8%1.7%
New Hempstead5,657+3.8%1.6%
Montebello4,828+3.8%1.4%
  • Pomona
  • Sloatsburg
  • Piermont
  • Upper Nyack
  • Hillburn
  • Grand View-on-Hudson
  • South Nyack

19 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).

Rockland County, Homes

Homes in Rockland County

Of Rockland County's 108,576 homes, 57% are detached houses, against 41% across New York; 20% are in buildings of five or more homes. Much of Rockland County is recent building: 13% of its homes have gone up since 2000 and the middle year built is 1970, against 1958 for New York. 68% 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 in Rockland County, New York, 2019 to 2023
HomesRockland CountyNew York
Housing units108,5768,539,536
Detached houses57%41%
In buildings of 5 or more20%34%
Mobile homes1%2%
Built before 196028%53%
Built since 200013%12%
Middle year built19701958
Owner-occupied68%54%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.