Radon testing & mitigation in Jefferson County, PA
56% of basement tests here came back at or above 4 pCi/L, well above the statewide 37%. That means about one in 2 homes tested needs a fix.
Jefferson County radon test data
Share of basement tests ≥ 4 pCi/L
First floor: 28% of 595 tests ≥ 4 pCi/L, median 2.0
Source: computed 2026-10-11 from PA DEP's Radon Test Results, Sept 1986 - Current (data.pa.gov, public domain). Counts tests, not homes: repeat and post-mitigation tests are included. Only a test tells you your home's level.
0 DEP-certified firms have a business address in Jefferson County (0 offer mitigation), with 0 certified individuals between them. Get free quotes
No DEP-certified firms list an address in this county. Firms based in the neighboring counties below often serve nearby areas.
Neighboring counties
Armstrong (2 firms) · Clarion (0 firms) · Clearfield (1 firms) · Elk (1 firms) · Forest (0 firms) · Indiana (2 firms). Firms often serve across county lines.
Adjacency from U.S. Census Bureau county adjacency file.