Radon levels in Dauphin County, Pennsylvania

ModerateEPA Zone 1

Predicted long-term basement average of 3.4 pCi/L (model estimate) across 24 ZIP codes - about 1.9× the US average of 1.8, about 1.5× the Pennsylvania average of 2.3. Ranked #15 of 67 Pennsylvania counties.

Test Dauphin County, PA - the EPA says "consider fixing" in this range

The predicted basement average here is 3.4 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.

3.4 ± 0.09

pCi/L predicted basement mean (model SD)

2.1 ± 0.08

pCi/L predicted upstairs (above-ground) mean

1.8-5.4

range of ZIP-level basement predictions in the county

What this means for Dauphin

The typical Dauphin County home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and roughly one home in several in a moderate area will test above 4.

Note that the EPA classifies Dauphin County as Zone 1 while the newer model predicts 3.4 pCi/L. The zone map predates two decades of test data; where they disagree, we grade on the model but show both. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable Pennsylvania counties: Clinton County (3.4), Fulton County (3.4), Carbon County (3.3), Lycoming County (3.4). The state's highest is Lebanon County at 4.8 pCi/L.

ZIP codes in Dauphin County

Predicted basement and upstairs means by ZIP (model estimate). ZIPs whose land is mostly in this county.

ZIPBasementUpstairsGrade
171123.6 ± 0.072.5Moderate
171114.2 ± 0.122.4High
171102.9 ± 0.081.9Moderate
171093.6 ± 0.112.5Moderate
170364.7 ± 0.102.7High
170572.3 ± 0.091.9Moderate
171042.5 ± 0.071.3Moderate
170333.3 ± 0.092.3Moderate
171032.6 ± 0.081.4Moderate
171132.9 ± 0.061.9Moderate
170325.4 ± 0.211.9High
171022.1 ± 0.121.2Moderate
170613.9 ± 0.101.9Moderate
170183.1 ± 0.071.9Moderate
170483.1 ± 0.061.7Moderate
170233.2 ± 0.071.9Moderate
179803.2 ± 0.061.7Moderate
170982.9 ± 0.071.6Moderate
170341.8 ± 0.061.3Low
171012.2 ± 0.081.4Moderate
170972.9 ± 0.061.6Moderate
170303.1 ± 0.071.7Moderate
170802.6 ± 0.081.4Moderate
179782.8 ± 0.071.6Moderate

If your test comes back at 4 pCi/L or higher

Mitigation is a routine job: a fan-driven pipe that vents soil gas from under the slab to above the roofline, typically $800-$2,500 installed (typical range; local quotes vary). Use certified professionals: EPA find-a-professional. Read the full mitigation guide.

Dauphin County radon questions

Is radon high in Dauphin County, Pennsylvania?
Moderate. The model predicts a long-term basement average of 3.4 pCi/L in Dauphin County (about 1.9× the US average of 1.8 and about 1.5× the Pennsylvania average of 2.3). That is in the 2-4 pCi/L range where the EPA recommends considering mitigation. Ranked 15 of 67 Pennsylvania counties.
Should I test for radon in Dauphin County?
Yes, soon. With a predicted average of 3.4 pCi/L and at least one ZIP predicted at 5.4, many homes in Dauphin County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.
What does EPA Radon Zone 1 mean for Dauphin County?
Zone 1 - highest potential (predicted average > 4 pCi/L). The zone map dates from 1993 and classifies whole counties. The newer model's predicted average of 3.4 pCi/L does not line up with Zone 1, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.
How much does radon mitigation cost in Dauphin County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Pennsylvania quotes vary with foundation type (slab, crawlspace, basement), home size and local labor. Get two or three bids from certified mitigators listed by your state radon program or the EPA's find-a-professional page.

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