---
title: "Certified Radon Mitigation & Testing in Jefferson County, PA | Radon Roster"
description: "0 PA DEP-certified radon firms in Jefferson County: 56% of basement tests at or above 4 pCi/L. Contacts, DEP cert IDs and local data."
canonical: https://radonroster.com/pa/county/jefferson/
---

[Pennsylvania](https://radonroster.com/)›[Counties](https://radonroster.com/pa/counties/)›Jefferson

# 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

Jefferson**56%**

Statewide**37%**

Share of basement tests ≥ 4 pCi/L

**4.7**median basement pCi/L

**4,562**basement tests on record

**#9**of 67 PA counties by share ≥ 4

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](https://data.pa.gov/Energy-and-the-Environment/Radon-Test-Results-September-1986-Current-Annual-C/vkjb-sx3k) (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](https://radonroster.com/get-quotes/?county=jefferson)

**No DEP-certified firms list an address in this county.** Firms based in the neighboring counties below often serve nearby areas.

## Neighboring counties

[Armstrong](https://radonroster.com/pa/county/armstrong/) (2 firms) · [Clarion](https://radonroster.com/pa/county/clarion/) (0 firms) · [Clearfield](https://radonroster.com/pa/county/clearfield/) (1 firms) · [Elk](https://radonroster.com/pa/county/elk/) (1 firms) · [Forest](https://radonroster.com/pa/county/forest/) (0 firms) · [Indiana](https://radonroster.com/pa/county/indiana/) (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 Jefferson mitigators[Request quotes](https://radonroster.com/get-quotes/?county=jefferson)

Our advice

## Before you hire in Jefferson

1. Ask for the DEP cert ID and match it to the listing.
2. Get at least two written quotes for mitigation.
3. Retest after the system is installed.

PA Radon Hotline **800-237-2366**

Typical mitigation cost

$786–$1,274

National range (HomeAdvisor). No local price data; quotes vary by foundation type.

[Estimate your cost →](https://radonroster.com/radon-mitigation-cost/)

## Want firms to contact you?

Send one request to certified mitigators who serve Jefferson.

[Request quotes](https://radonroster.com/get-quotes/?county=jefferson)