Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Elk County, Pennsylvania
EPA puts Elk County in Zone 2, its middle radon zone, and high results are common there: 47.0% of the 66 radon tests reported to CDC (2020) came back 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
47.0%
16.7 pts above PA
- Elk
- 47.0%
- PA
- 30.3%
66 tests, 2020
Median result
3.5pCi/L
Below action level
- Elk
- 3.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
66
61st of 63 by tests
- Elk
- 66
- Montgomery
- 10,508
Reported to CDC before any fix, 2020
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in PA
11 of 63
Top quarter
- Elk
- 47.0%
- Perry
- 57.7%
By share, of 63 with 30+ tests
Read a result for Elk County
Starts at Elk County's median, 3.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.5 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. Elk County's median reported result, 2020.
The data
Elk County, At a glance
Elk County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Elk County is a
USGS geologic potential: Moderate across 67% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Elk County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 48.2% |
| 2015 | 34.8% |
| 2016 | 43.6% |
| 2017 | 38.8% |
| 2018 | 42.5% |
| 2019 | 53.3% |
| 2020 | 47.0% |
2020: 47.0%. Across these years the share ran from 34.8% to 53.3%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 66 tests reported to CDC for Elk County over 2020, 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: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).
Elk County, Compared
Elk County radon figures, compared
Calculated by Radon411In Elk County, about 5 in 10 reported tests in 2020 (31 of 66) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 21.5 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Elk County runs 16.7 points above its state.
Of 3 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 38.6% (Jefferson County) to 47.5% (Clearfield County). By share, Elk County is 11th of 63 Pennsylvania counties with 30 or more tests for the same period.
Year by year, 2014 opened at 48.2% and 2020 closed at 47.0% (about level), with 2019 the high at 53.3%. Half the tests came in under 3.5 pCi/L and half over it; the single highest reached 34.4 pCi/L. Below the action level, 19 tests (28.8%) came in under 2 pCi/L, against 44.3% statewide, and 16 tests (24.2%) fell between 2 and 4, against 25.4% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 47.0% share point the same way here. USGS geology rates 67% of the county's land moderate radon potential.
The busiest year on file was 2015, with 161 tests reported; the quietest, 2019, had 60.
Elk CountyPennsylvania, pooled
47.0% % of tests30.3% % of tests
| Year | Tests | Elk County, at or above 4 pCi/L | Pennsylvania, pooled |
|---|---|---|---|
| 2014 | 137 | 48.2% | 36.1% |
| 2015 | 161 | 34.8% | 37.8% |
| 2016 | 94 | 43.6% | 34.4% |
| 2017 | 103 | 38.8% | 35.1% |
| 2018 | 87 | 42.5% | 30.5% |
| 2019 | 60 | 53.3% | 31.4% |
| 2020 | 66 | 47.0% | 30.3% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Elk County, State data
Pennsylvania's own radon test data
MeasuredWhat Pennsylvania's own agencies publish about radon tests in Elk County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Pennsylvania DEP reports for the ZIP codes in Elk County
Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 15 ZIP codes that lie wholly or partly in Elk County, each with the state's own figures for it. Period: Period not stated by DEP.
| ZIP code | What the state reports |
|---|---|
| 15821 | Basement: figures not shown; First floor: figures not shown |
| 15823 | Basement: average 4.9 pCi/L, 59 tests; First floor: figures not shown |
| 15827 | Basement: figures not shown |
| 15831 | Basement: figures not shown |
| 15832 | Basement: figures not shown; First floor: figures not shown |
| 15841 | Basement: figures not shown |
| 15845 | Basement: average 13.1 pCi/L, 141 tests; First floor: figures not shown |
| 15846 | Basement: average 11.9 pCi/L, 157 tests; First floor: average 10.0 pCi/L, 33 tests |
| 15853 | Basement: average 5.9 pCi/L, 341 tests; First floor: average 8.3 pCi/L, 55 tests |
| 15857 | Basement: average 12.8 pCi/L, 902 tests; First floor: average 4.6 pCi/L, 69 tests |
| 15860 | Basement: figures not shown; First floor: figures not shown |
| 15868 | Basement: average 9.5 pCi/L, 78 tests; First floor: figures not shown |
| 15870 | Basement: average 5.0 pCi/L, 36 tests; First floor: figures not shown |
| 16734 | Basement: figures not shown |
| 16735 | Basement: average 9.2 pCi/L, 206 tests; First floor: average 6.5 pCi/L, 31 tests |
- DEP's report gives the number of tests, the highest result and the average result for each floor tested; it states no period.
- DEP says the smartest thing to do is to test your home for radon, no matter where you live.
- A ZIP code that crosses the county line is listed whole; its figures cover all of it.
Measured: Pennsylvania DEP data, Period not stated by DEP.
Elk County, Geology
The ground under Elk County
PredictedUSGS's geologic map splits Elk County: 66.7% of its land is moderate radon potential and 33.3% high. The map puts 66.7% of Elk County in the area it calls High Plateau and 27.1% in Mountainous High Plateau, with one smaller area beside them. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| High Plateau | Marine and continental Devonian-Pennsylvanian shale, sandstone, limestone, siltstone, and coal. | Moderate | 10 | 66.7% |
| Mountainous High Plateau | Sandstone, shale and conglomerate. | High | 12 | 27.1% |
| Pennsylvanian Rocks of the Pittsburgh Low Plateau | Pennsylvanian marine shale, siltstone, sandstone, limestone, and coal. | High | 14 | 6.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Elk County beside the ground around it
Pennsylvania as a whole has more high-potential ground than Elk County: 70.4% of its land, against 33.3% here. Of the 6 counties that border it, 3 have more high-potential ground, Clearfield County the most at 83.5%.
The map rates the ground, not the air in any home.
Local help
Elk County, Local resources
Radon testing and mitigation in Elk County
- Radon DivisionRadon Division, run by Department of Environmental Protection, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Pennsylvania.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Through an EPA-funded program, hospitals give parents of newborn children a packet of information which includes a coupon for a free radon test kit from the DEP.
- Compare kits
- Professionals in Pennsylvania151 professionals are listed in Pennsylvania.
What Pennsylvania's program says
- Phone
- 800-237-2366
- Licensing of radon professionals
The Radon Certification Act requires DEP to establish by regulation, a certification program for persons conducting radon gas and radon progeny testing, laboratory analysis and mitigation of radon contamination in buildings.
What it means
Elk County, Questions
Questions about radon in Elk County
Are radon levels high in Elk County?
In 2020, 47.0% of the radon tests reported to CDC for Elk County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.5 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 10 reported a higher share; pooled, the state comes to 30.3%.
Which counties border Elk County?
Elk County borders 6 counties: Jefferson County, McKean County, Forest County, Cameron County, Clearfield County and Warren County.
Products
Elk County, Products
Testing a home in Elk County
In Elk County, 47.0% of 66 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Elk County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-3699 radon monitor with a 2.1-inch touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
First reading: Within 1 hour
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Elk County, Bordering counties
Counties bordering Elk County
Calculated by Radon411- Radon levels in Cameron CountyEPA zone 1
75.0%at or above 4 pCi/L
Median 4.8 pCi/L · 4 tests · 28.0 points above Elk County
- Radon levels in Forest CountyEPA zone 2
56.3%at or above 4 pCi/L
Median 5.0 pCi/L · 16 tests · 9.3 points above Elk County
- Radon levels in Clearfield CountyEPA zone 1
47.5%at or above 4 pCi/L
Median 3.6 pCi/L · 394 tests · 0.5 points above Elk County
- Radon levels in Warren CountyEPA zone 2
38.7%at or above 4 pCi/L
Median 2.8 pCi/L · 119 tests · 8.3 points below Elk County
- Radon levels in Jefferson CountyEPA zone 2
38.6%at or above 4 pCi/L
Median 2.6 pCi/L · 254 tests · 8.4 points below Elk County
- Radon levels in McKean CountyEPA zone 2
10.5%at or above 4 pCi/L
Median 1.7 pCi/L · 19 tests · 36.5 points below Elk County
Elk County, Cities and towns
Cities and towns in Elk County
About 29,926 people live in Elk County by the Census Bureau's estimate for July 1, 2025, 1,014 fewer than in 2020 (−3.3%). That works out to 36 people per square mile of land. Its largest town, St. Marys, has 12,253 residents, 40.9% of the total. Together its 3 incorporated places hold 61.6% of those residents; the other 38.4% live outside any of them. Reported testing is thin here: 66 tests over 2020, or 2.2 for every 1,000 residents (2025 estimate), where Pennsylvania as a whole comes to 7.2.
From St. Marys to Johnsonburg, CDC publishes no figure by town: each reads Elk County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| St. Marys | 12,253 | −3.6% | 40.9% |
| Ridgway | 3,893 | −3.2% | 13.0% |
| Johnsonburg | 2,291 | −4.3% | 7.7% |
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).
Elk County, Homes
Homes in Elk County
Elk County is a place of houses on their own lots: 81% of its 16,876 homes are detached single-family houses, against 57% across Pennsylvania. Half of its homes were built before 1961, close to Pennsylvania's 1965: 49% date from before 1960 and 9% from 2000 or later. Owners live in 79% of the occupied homes (Pennsylvania: 69%), so for most households a test and a fix are their own to order.
| Homes | Elk County | Pennsylvania |
|---|---|---|
| Housing units | 16,876 | 5,779,663 |
| Detached houses | 81% | 57% |
| In buildings of 5 or more | 5% | 13% |
| Mobile homes | 6% | 4% |
| Built before 1960 | 49% | 45% |
| Built since 2000 | 9% | 14% |
| Middle year built | 1961 | 1965 |
| Owner-occupied | 79% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.