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An independent directory built from Pennsylvania DEP certification recordsLists dated Oct 1, 2026 · About our data

Radon testing & mitigation in Clarion County, PA

48% 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.

Clarion County radon test data

Clarion48%
Statewide37%

Share of basement tests ≥ 4 pCi/L

3.8median basement pCi/L
3,576basement tests on record
#29of 67 PA counties by share ≥ 4

First floor: 20% of 469 tests ≥ 4 pCi/L, median 1.7

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 Clarion 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) · Butler (12 firms) · Forest (0 firms) · Jefferson (0 firms) · Venango (2 firms). Firms often serve across county lines.

Adjacency from U.S. Census Bureau county adjacency file.

Want firms to contact you?One request to Clarion mitigatorsRequest quotes