Radon in Armstrong County, Pennsylvania

More than half of homes tested here were at or above the EPA action level.

1,627 home tests, 2016–2026, Pennsylvania DEP
  • Below 2 pCi/L: 24%
  • 2 to 4 pCi/L: 26%
  • 4 pCi/L or more: 51%
The line marks the EPA action level, 4 pCi/L.
Typical level
4.1 pCi/L
EPA radon zone
Zone 1
In Pennsylvania
6th of 67

EPA Zone 1, the highest radon potential (predicted average above 4 pCi/L). The EPA zone map dates from 1993 and is meant for planning; high levels are found in every zone.

What fixing radon costs in Armstrong County

From 112 standard systems installed in the county since 2021, as reported to the state. Half of homeowners paid between the low and high figures.

What to do next

  1. Test your home

    Radon levels vary between neighboring houses, so area data can't tell you your own home's level. A short-term test takes 2 to 7 days in the lowest lived-in floor. A long-term test (90 days or more) gives a more reliable average.

  2. If your result is 4 pCi/L or more, fix it

    A certified professional installs a sub-slab system: a pipe and a quiet fan that pull radon from under the foundation and vent it above the roof. It usually takes a day; the costs are above.

    It works: across Pennsylvania, the typical level dropped from 7.7 to 1.0 pCi/L after mitigation, and 95% of homes ended up below the action level.

  3. Use a certified professional

    Pennsylvania requires radon testers and mitigators to be certified. The state publishes the list of certified mitigation firms by county.

How Armstrong County compares

Share of homes tested at or above 4 pCi/L, with neighboring counties. Lab data 2008–2017, the only source that covers every state.

Share of homes tested at or above 4 pCi/L
Jefferson County58%
Armstrong County58%
Indiana County52%
Butler County49%
Clarion County48%
Westmoreland County41%
Pennsylvania41%
United States36%

Radon by zip code in Armstrong County

Home tests reported to the Pennsylvania DEP since October 2016, most-tested zip codes first.

Zip codeHomes testedTests4 or moreMedian
16201
58453%4.3 pCi/L
16229
26844%3.3 pCi/L
16226
21345%3.3 pCi/L
15774
12556%4.8 pCi/L
16249
6952%4.3 pCi/L
15686
6461%6.3 pCi/L
16262
6452%4.3 pCi/L
16222
4949%3.8 pCi/L
16218
3661%4.8 pCi/L
16259
3070%6.3 pCi/L
15673
2945%3.3 pCi/L
15736
2879%9.3 pCi/L
16210Too few tests17––
16228Too few tests10––
16253Too few tests10––
16236Too few tests7––
16263Too few tests6––
16212Too few tests5––
16245Too few tests5––
16238Too few tests3––
15682Too few tests2––
16223Too few tests2––
16250Too few tests1––

"–" means fewer than 20 tests, too few for a reliable figure.

Sources

Last updated October 2026. How we calculate these numbers.