Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Northumberland County, Pennsylvania
EPA puts Northumberland County in Zone 1, its highest radon zone, and high results are common there: 49.8% of the 275 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
49.8%
19.5 pts above PA
- Northumberland
- 49.8%
- PA
- 30.3%
275 tests, 2020
Median result
3.9pCi/L
Below action level
- Northumberland
- 3.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2020
Tests reported
275
39th of 63 by tests
- Northumberland
- 275
- Montgomery
- 10,508
Reported to CDC before any fix, 2020
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in PA
7 of 63
Top quarter
- Northumberland
- 49.8%
- Perry
- 57.7%
By share, of 63 with 30+ tests
Read a result for Northumberland County
Starts at Northumberland County's median, 3.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.9 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. Northumberland County's median reported result, 2020.
The data
Northumberland County, At a glance
Northumberland County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Northumberland County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Northumberland County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 49.7% |
| 2015 | 53.4% |
| 2016 | 50.3% |
| 2017 | 39.7% |
| 2018 | 33.5% |
| 2019 | 35.5% |
| 2020 | 49.8% |
2020: 49.8%. Across these years the share ran from 33.5% to 53.4%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 275 tests reported to CDC for Northumberland 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).
Northumberland County, Compared
Northumberland County radon figures, compared
Calculated by Radon411In Northumberland County, about 5 in 10 reported tests in 2020 (137 of 275) were at or above EPA's action level. Against the national pool of 25.5%, the gap is 24.3 points higher. Across 67 Pennsylvania counties pooled together, 30.3% of tests reached that level, so Northumberland County runs 19.5 points above its state.
Of 9 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 6 a smaller one; the spread is 34.7% (Columbia County) to 57.7% (Perry County). By share, Northumberland County is 7th of 63 Pennsylvania counties with 30 or more tests for the same period.
Year by year, 2014 opened at 49.7% and 2020 closed at 49.8% (about level), with 2015 the high at 53.4%. Half the tests came in under 3.9 pCi/L and half over it; the single highest reached 82.0 pCi/L. Below the action level, 82 tests (29.8%) came in under 2 pCi/L, against 44.3% statewide, and 56 tests (20.4%) fell between 2 and 4, against 25.4% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 49.8% share point the same way here. USGS geology rates 100% of the county's land high radon potential.
The busiest year on file was 2019, with 434 tests reported; the quietest, 2014, had 197.
Northumberland CountyPennsylvania, pooled
49.8% % of tests30.3% % of tests
| Year | Tests | Northumberland County, at or above 4 pCi/L | Pennsylvania, pooled |
|---|---|---|---|
| 2014 | 197 | 49.7% | 36.1% |
| 2015 | 253 | 53.4% | 37.8% |
| 2016 | 394 | 50.3% | 34.4% |
| 2017 | 345 | 39.7% | 35.1% |
| 2018 | 391 | 33.5% | 30.5% |
| 2019 | 434 | 35.5% | 31.4% |
| 2020 | 275 | 49.8% | 30.3% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Northumberland County, State data
Pennsylvania's own radon test data
MeasuredWhat Pennsylvania's own agencies publish about radon tests in Northumberland 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 Northumberland County
Pennsylvania DEP publishes its figures by ZIP code, not by county. These are the 28 ZIP codes that lie wholly or partly in Northumberland County, each with the state's own figures for it. Period: Period not stated by DEP.
| ZIP code | What the state reports |
|---|---|
| 17017 | Basement: average 19.0 pCi/L, 141 tests; First floor: average 8.9 pCi/L, 34 tests |
| 17730 | Basement: figures not shown; First floor: figures not shown |
| 17749 | Basement: figures not shown; First floor: figures not shown |
| 17756 | Basement: average 12.2 pCi/L, 1,154 tests; First floor: average 3.6 pCi/L, 250 tests |
| 17772 | Basement: average 6.1 pCi/L, 233 tests; First floor: average 3.0 pCi/L, 30 tests |
| 17777 | Basement: average 8.4 pCi/L, 712 tests; First floor: average 2.9 pCi/L, 104 tests |
| 17801 | Basement: average 10.5 pCi/L, 1,022 tests; First floor: average 3.2 pCi/L, 253 tests |
| 17821 | Basement: average 9.7 pCi/L, 3,919 tests; First floor: average 5.5 pCi/L, 633 tests |
| 17823 | Basement: average 21.5 pCi/L, 60 tests; First floor: figures not shown |
| 17824 | Basement: average 11.9 pCi/L, 795 tests; First floor: average 7.0 pCi/L, 96 tests |
| 17830 | Basement: average 32.0 pCi/L, 180 tests; First floor: figures not shown |
| 17832 | Basement: average 3.8 pCi/L, 32 tests; First floor: figures not shown |
| 17834 | Basement: average 7.8 pCi/L, 294 tests; First floor: figures not shown |
| 17836 | Basement: figures not shown; First floor: figures not shown |
| 17840 | Basement: figures not shown; First floor: figures not shown |
| 17847 | Basement: average 8.3 pCi/L, 1,494 tests; First floor: average 3.2 pCi/L, 235 tests |
| 17850 | Basement: figures not shown; First floor: figures not shown |
| 17851 | Basement: average 3.1 pCi/L, 182 tests; First floor: average 1.0 pCi/L, 43 tests |
| 17857 | Basement: average 12.9 pCi/L, 1,143 tests; First floor: average 3.8 pCi/L, 180 tests |
| 17860 | Basement: average 20.2 pCi/L, 185 tests; First floor: figures not shown |
| 17865 | Basement: figures not shown; First floor: figures not shown |
| 17866 | Basement: average 4.8 pCi/L, 357 tests; First floor: average 1.9 pCi/L, 71 tests |
| 17867 | Basement: figures not shown; First floor: figures not shown |
| 17868 | Basement: average 8.5 pCi/L, 145 tests; First floor: average 4.2 pCi/L, 50 tests |
| 17872 | Basement: average 10.7 pCi/L, 307 tests; First floor: average 1.8 pCi/L, 83 tests |
| 17881 | Basement: average 6.4 pCi/L, 72 tests; First floor: figures not shown |
| 17941 | Basement: average 31.5 pCi/L, 34 tests; First floor: figures not shown |
| 17964 | Basement: average 30.1 pCi/L, 42 tests; First floor: figures not shown |
- 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.
Northumberland County, Geology
The ground under Northumberland County
PredictedUSGS's geologic map puts all of Northumberland County's mapped land in one class: high radon potential. All of it lies in the area the map calls Appalachian Mountain Section, to which USGS gives a radon index of 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Appalachian Mountain Section | Paleozoic sandstone, shale, and limestone. | High | 12 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Northumberland County beside the ground around it
Northumberland County has more high-potential ground than Pennsylvania as a whole: 100% of its land against 70.4%. Of the 9 counties that border it, none has as large a share of high-potential ground; Juniata County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Northumberland County, Local resources
Radon testing and mitigation in Northumberland 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
Northumberland County, Questions
Questions about radon in Northumberland County
Are radon levels high in Northumberland County?
In 2020, 49.8% of the radon tests reported to CDC for Northumberland County, Pennsylvania were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.9 pCi/L. Of 63 Pennsylvania counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 30.3%.
Which counties border Northumberland County?
Northumberland County borders 9 counties: Montour County, Columbia County, Union County, Snyder County, Schuylkill County, Lycoming County, Dauphin County, Perry County and Juniata County.
Products
Northumberland County, Products
Testing a home in Northumberland County
In Northumberland County, 49.8% of 275 tests reported to CDC in 2020 reached 4 pCi/L, against 30.3% pooled across Pennsylvania. In Zone 1 the year-round level in Northumberland 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
Wave Plus battery radon and air quality monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Northumberland County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Northumberland County
Explore
Northumberland County, Bordering counties
Counties bordering Northumberland County
Calculated by Radon411- Radon levels in Perry CountyEPA zone 1
57.7%at or above 4 pCi/L
Median 4.9 pCi/L · 189 tests · 7.9 points above Northumberland County
- Radon levels in Schuylkill CountyEPA zone 1
53.5%at or above 4 pCi/L
Median 4.5 pCi/L · 797 tests · 3.7 points above Northumberland County
- Radon levels in Juniata CountyEPA zone 1
52.9%at or above 4 pCi/L
Median 4.4 pCi/L · 87 tests · 3.1 points above Northumberland County
- Radon levels in Lycoming CountyEPA zone 1
45.2%at or above 4 pCi/L
Median 3.5 pCi/L · 562 tests · 4.6 points below Northumberland County
- Radon levels in Union CountyEPA zone 1
44.5%at or above 4 pCi/L
Median 3.3 pCi/L · 182 tests · 5.3 points below Northumberland County
- Radon levels in Snyder CountyEPA zone 1
42.4%at or above 4 pCi/L
Median 2.8 pCi/L · 99 tests · 7.4 points below Northumberland County
- Radon levels in Montour CountyEPA zone 1
41.5%at or above 4 pCi/L
Median 3.1 pCi/L · 123 tests · 8.3 points below Northumberland County
- Radon levels in Dauphin CountyEPA zone 1
36.9%at or above 4 pCi/L
Median 2.0 pCi/L · 2,986 tests · 12.9 points below Northumberland County
- Radon levels in Columbia CountyEPA zone 1
34.7%at or above 4 pCi/L
Median 2.0 pCi/L · 409 tests · 15.1 points below Northumberland County
Northumberland County, Cities and towns
Cities and towns in Northumberland County
About 89,920 people live in Northumberland County by the Census Bureau's estimate for July 1, 2025, 1,624 fewer than in 2020 (−1.8%). That works out to 196 people per square mile of land. No town dominates: Sunbury, the largest, has 9,495 residents, 10.6% of the total. Together its 13 incorporated places hold 45.7% of those residents; the other 54.3% live outside any of them. Reported testing is thin here: 275 tests over 2020, or 3.1 for every 1,000 residents (2025 estimate), where Pennsylvania as a whole comes to 7.2.
From Sunbury to McEwensville, CDC publishes no figure by town: each reads Northumberland County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Sunbury | 9,495 | −2.1% | 10.6% |
| Shamokin | 6,764 | −2.6% | 7.5% |
| Milton | 6,457 | −2.3% | 7.2% |
| Mount Carmel | 5,579 | −2.3% | 6.2% |
| Northumberland | 3,800 | −2.2% | 4.2% |
| Kulpmont | 2,688 | −2.5% | 3.0% |
| Watsontown | 2,188 | −1.8% | 2.4% |
| Riverside | 1,991 | −2.0% | 2.2% |
| Turbotville | 660 | −2.8% | 0.7% |
| Marion Heights | 552 | −1.8% | 0.6% |
| Herndon | 341 | −2.8% | 0.4% |
| Snydertown | 316 | −2.2% | 0.4% |
- McEwensville
13 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).
Northumberland County, Homes
Homes in Northumberland County
Of Northumberland County's 43,395 homes, 62% are detached houses, against 57% across Pennsylvania; 7% are in buildings of five or more homes. The homes are older than Pennsylvania's as a whole: half were built before 1955 (1965 for Pennsylvania), and 55% date from before 1960. 75% of occupied homes are lived in by their owner (Pennsylvania: 69%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Northumberland County | Pennsylvania |
|---|---|---|
| Housing units | 43,395 | 5,779,663 |
| Detached houses | 62% | 57% |
| In buildings of 5 or more | 7% | 13% |
| Mobile homes | 4% | 4% |
| Built before 1960 | 55% | 45% |
| Built since 2000 | 8% | 14% |
| Middle year built | 1955 | 1965 |
| Owner-occupied | 75% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.