Radon Testing & Mitigation in Cambria County, PA
44% of 16,280 basement radon tests reported to PA DEP in Cambria County measured 4.0 pCi/L or higher, EPA's action level (median 3.5 pCi/L).
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Radon in Cambria County: 44% of the 16,280 basement tests reported to PA DEP measured 4.0 pCi/L or higher, EPA's action level, 7 points above the 37% statewide share. The county ranks 42nd highest of 67, and the median result is 3.5 pCi/L. Only a test shows one home's level.
Radon Test Results by ZIP Code in Cambria County
33 ZIP codes in Cambria County have at least 20 basement tests on record. Among those with 100 or more, the highest share at or above 4.0 pCi/L is in 16640 (Flinton): 59% of 155 tests. The lowest is in 15901 (Johnstown): 29% of 126 tests.
| ZIP code | Post office | Basement tests | Median pCi/L | At or above 4.0 |
|---|---|---|---|---|
| 15905 | Johnstown | 4,828 | 3.7 | 46% |
| 15904 | Johnstown | 3,337 | 3.5 | 43% |
| 15931 | Ebensburg | 1,374 | 3.5 | 44% |
| 15902 | Johnstown | 804 | 2.9 | 38% |
| 15906 | Johnstown | 620 | 2.8 | 32% |
| 16630 | Cresson | 489 | 3.5 | 45% |
| 15909 | Johnstown | 432 | 4.4 | 52% |
| 15943 | Nanty Glo | 425 | 1.8 | 31% |
| 16668 | Patton | 399 | 3.8 | 47% |
| 15946 | Portage | 375 | 2.7 | 36% |
| 15940 | Loretto | 338 | 3.7 | 49% |
| 15714 | Northern Cambria | 314 | 2.7 | 32% |
| 15938 | Lilly | 233 | 3.6 | 45% |
| 15722 | Carrolltown | 207 | 4.8 | 56% |
| 16646 | Hastings | 172 | 3.4 | 48% |
Show all 33 ZIP codes
| 15956 | South Fork | 171 | 3.5 | 44% |
| 15942 | Mineral Point | 167 | 4.3 | 53% |
| 16641 | Gallitzin | 157 | 2.5 | 29% |
| 16640 | Flinton | 155 | 4.9 | 59% |
| 15958 | Summerhill | 151 | 4.1 | 54% |
| 15955 | Sidman | 129 | 3.4 | 41% |
| 15901 | Johnstown | 126 | 2.0 | 29% |
| 15952 | Salix | 111 | 3.2 | 45% |
| 16613 | Ashville | 106 | 4.2 | 52% |
| 15762 | Nicktown | 95 | 6.0 | 59% |
| 15927 | Colver | 79 | 4.8 | 53% |
| 15963 | Windber (part) | 67 | 3.3 | 40% |
| 16636 | Dysart | 66 | 5.9 | 62% |
| 16639 | Fallentimber | 39 | 2.5 | 31% |
| 15907 | Johnstown | 35 | 3.2 | 40% |
| 16624 | Chest Springs | 31 | 3.8 | 48% |
| 15948 | Revloc | 24 | 1.8 | 29% |
| 15951 | St. Michael | 21 | 2.6 | 24% |
| Cambria County | 16,280 | 3.5 | 44% | |
| Pennsylvania | 2,629,492 | 2.8 | 37% | |
See your ZIP in the table?
Get matched with a DEP-certified radon professionalFirst-floor tests in Cambria County: 942 on record, median 1.7 pCi/L, 23% at or above 4.0 pCi/L.
EPA's Map of Radon Zones (1993) places Cambria County in Zone 2, its middle category (predicted average between 2 and 4 pCi/L). The map is a county-wide prediction; the figures in this table are measurements.
Figures count tests, not homes. A home tested more than once is counted each time, and tests run after a mitigation system was installed are included because the dataset does not separate them. ZIP codes with fewer than 20 basement tests are not shown.
Housing Age in Cambria County
80% of Cambria County's 64,456 housing units were built before 1980, 13 points above the 67% statewide figure; 30% date from before 1940. Those homes predate EPA's 1994 model standards for radon-resistant construction. Age does not predict a test result: EPA's guidance is that any home, new or old, may have a radon problem.
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, table B25034. Counts all housing units, including vacant and seasonal ones. Retrieved September 29, 2026.
Bedrock Under Cambria County
Glenshaw Formation (Pennsylvanian; shale) underlies 46% of the county. Casselman Formation (Pennsylvanian; clastic sedimentary rock and shale) underlies 24% of the county.
Mapped bedrock describes an area. The USGS states that its radon assessment cannot be applied to individual homes. More on Pennsylvania radon and geology.
Sources: U.S. Geological Survey State Geologic Map Compilation, from Pennsylvania Geological Survey Map 1 (1980; digital edition 2001). Retrieved September 29, 2026. U.S. Geological Survey Open-File Report 93-292-C, Geologic Radon Potential of EPA Region 3 (1993).
Home Purchases in Cambria County
Lenders reported 994 home-purchase mortgages originated in Cambria County in 2024. The count covers financed purchases only; cash purchases are not in the data. See radon in a Pennsylvania home sale.
Source: FFIEC Home Mortgage Disclosure Act data, 2024. Retrieved September 29, 2026.
Municipalities in Cambria County
Cambria County has 63 municipalities: 1 city, 32 boroughs and 30 townships.
Show all 63 municipalities
Adams township, Allegheny township, Ashville borough, Barr township, Blacklick township, Brownstown borough, Cambria township, Carrolltown borough, Cassandra borough, Chest township, Chest Springs borough, Clearfield township, Conemaugh township, Cresson borough, Cresson township, Croyle township, Daisytown borough, Dale borough, Dean township, East Carroll township, East Conemaugh borough, East Taylor township, Ebensburg borough, Ehrenfeld borough, Elder township, Ferndale borough, Franklin borough, Gallitzin borough, Gallitzin township, Geistown borough, Hastings borough, Jackson township, Johnstown city, Lilly borough, Lorain borough, Loretto borough, Lower Yoder township, Middle Taylor township, Munster township, Nanty-Glo borough, Northern Cambria borough, Patton borough, Portage borough, Portage township, Reade township, Richland township, Sankertown borough, Scalp Level borough, South Fork borough, Southmont borough, Stonycreek township, Summerhill borough, Summerhill township, Susquehanna township, Tunnelhill borough, Upper Yoder township, Vintondale borough, Washington township, West Carroll township, West Taylor township, Westmont borough, White township, Wilmore borough.
Source: U.S. Census Bureau, 2025 Gazetteer Files, county subdivisions. Retrieved September 29, 2026.
City Pages in Cambria County
Neighboring Counties
- Radon in Bedford County → 55% of 4,032 basement tests at or above 4.0 pCi/L
- Radon in Blair County → 43% of 17,286 basement tests at or above 4.0 pCi/L
- Radon in Clearfield County → 53% of 10,770 basement tests at or above 4.0 pCi/L
- Radon in Indiana County → 46% of 9,096 basement tests at or above 4.0 pCi/L
- Radon in Somerset County → 44% of 5,560 basement tests at or above 4.0 pCi/L
- Radon in Westmoreland County → 40% of 66,661 basement tests at or above 4.0 pCi/L
- All 67 Pennsylvania county radon pages
DEP-Certified Mitigation Firms Based in County
1 DEP-certified mitigation firm is physically based in Cambria County. Firms from adjacent counties routinely serve here as well.
Source: PA DEP Certified Mitigation Firms Directory, July 2026. This reflects business address only — firms based elsewhere may also serve Cambria County.
Testing, Cost and Certification
Short-term tests run 48–96 hours; long-term tests run 90 days or more. At 4.0 pCi/L or higher, retest or mitigate. How radon testing works in a Pennsylvania real estate transaction.
Mitigation in Cambria County typically costs $825–$2,250. Pennsylvania radon mitigation cost guide.
Anyone testing or mitigating for pay must hold DEP certification under 25 Pa. Code § 240. How to verify a contractor in the PA DEP Radon Services Directory.
Frequently Asked Questions
What share of radon tests in Cambria County are at or above the EPA action level?
44% of the 16,280 basement tests reported to PA DEP from Cambria County measured 4.0 pCi/L or higher, against 37% statewide. The median result is 3.5 pCi/L, and 7% of tests measured 20 pCi/L or higher.
Which Cambria County ZIP code has the highest radon test results?
Among ZIP codes with at least 100 basement tests, 16640 (Flinton) has the highest share at or above 4.0 pCi/L: 59% of 155 tests, with a median of 4.9 pCi/L. 15901 (Johnstown) has the lowest, at 29%.
How does Cambria County compare with other Pennsylvania counties?
Cambria County ranks 42nd highest of 67 counties by share of basement tests at or above 4.0 pCi/L, at 44%. Among its neighbors, Bedford County has the highest share at 55% and Westmoreland County the lowest at 40%.
What bedrock is under Cambria County?
The largest mapped units are Glenshaw Formation (46% of the county) and Casselman Formation (24% of the county), according to the USGS compilation of the Pennsylvania Geological Survey state map.