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Radon testing & mitigation in Williamsport, PA

Williamsport sits in Lycoming County. In the PA DEP test dataset, 6,668 basement radon tests carry a Williamsport address. Their median was 2.9 pCi/L, and 39% came in at or above EPA's 4 pCi/L action level. Across all of Lycoming County it was 46%, and statewide 37%. Even where the average is lower, neighboring houses can test very differently, so every home should be tested.

Williamsport radon test data

Williamsport39%
Lycoming Co.46%
Statewide37%

Share of basement tests ≥ 4 pCi/L

2.9median pCi/L
6,668tests on record
1firms based here

City figures come from the municipality / mailing-address name in PA DEP's Radon Test Results (computed 2026-10-11). They count tests, not homes.

Below are the PA DEP-certified firms with a business address in Williamsport, then other firms in Lycoming County, then mitigation firms in the counties next door. Certified pros often travel, so ask each one whether they cover your street.

Read the Williamsport radon hiring guide → (how to verify certification, questions to ask, costs, FAQ)

Firms based in Williamsport (1)

Radon mitigation (reduction systems) (1 firm)

Firms certified to install radon reduction systems. Firms that also test are shown here once.

Jcn Radon Services Inc

✓ PA DEP certifiedMitigationTesting
Williamsport1 certified person

Address

Certified individuals

  • Stiger, Timothy E. (testing #3518, mitigation #3518)

DEP cert IDs

mitigation #3518 · mitigation #3565 · testing #3518

Source: DEP list DEP list, retrieved 2026-10-11 · Claim, correct or remove this listing

Call (570) 988-6800

Elsewhere in Lycoming County (1)

Radon testing (1 firm)

Mcclain, Joshua

✓ PA DEP certifiedTesting
Montoursville1 certified person

Address

Certified individuals

  • Mcclain, Joshua (testing #3414)

DEP cert IDs

testing #3414

Source: DEP list, retrieved 2026-10-11 · Claim, correct or remove this listing

Call (570) 560-2773

Mitigation firms in neighboring counties (2)

Conklin, George, Iv

✓ PA DEP certifiedMitigationClinton County
Loganton1 certified person

Address

Certified individuals

  • Conklin, George, Iv (mitigation #2769)

DEP cert IDs

mitigation #2769

Source: DEP list, retrieved 2026-10-11 · Claim, correct or remove this listing

Call (570) 433-8210

Ralston, Jeffrey

✓ PA DEP certifiedMitigationTestingColumbia County
Bloomsburg1 certified person

Address

Certified individuals

  • Ralston, Jeffrey (testing #3163, mitigation #3163)

DEP cert IDs

mitigation #3163 · testing #3163

Source: DEP list DEP list, retrieved 2026-10-11 · Claim, correct or remove this listing

Call (570) 384-3574

Lycoming County radon test data

Lycoming46%
Statewide37%

Share of basement tests ≥ 4 pCi/L

3.6median basement pCi/L
15,471basement tests on record
#36of 67 PA counties by share ≥ 4

First floor: 21% of 2,844 tests ≥ 4 pCi/L, median 1.6

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.

All Lycoming County listings → · Williamsport radon guide

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