Radon in Armstrong County, PA: Test Results by ZIP Code

Updated November 2026 · Data: Pennsylvania DEP radon test and mitigation databases, EPA Map of Radon Zones · Sources and method

Pennsylvania DEP has records of 5,553 radon tests in Armstrong County homes. Of those, 50.0% were at or above the EPA action level of 4 pCi/L, and the median result was 4 pCi/L. That share is higher than the Pennsylvania figure of 33.9%. Armstrong County is in EPA radon Zone 1 (highest potential). Below are results by ZIP code and community, by floor of the home, and what radon mitigation has cost in the county.

50.0%of tests at or above 4 pCi/L
4 pCi/Lmedian test result
5,553tests on record (PA DEP)
10.4%of tests at or above 20 pCi/L
$1,425median mitigation cost, 2022–2026 (50 systems)
Zone 1EPA radon zone

These are area results, not your home’s level. Homes next to each other can have very different radon levels. The only way to know yours is to test.

Radon test results by ZIP code in Armstrong County

ZIP codes with at least 20 tests on record. “At or above 4 pCi/L” is the share of tests at or above the EPA action level.

ZIP codeTestsMedian (pCi/L)At or above 4 pCi/L
156135043.646.6%
156567042.936.6%
15673673.344.8%
156861606.564.4%
156902094.150.7%
15736539.375.5%
157741045.055.8%
160252013.085.0%
16028494.251.0%
16049654.352.3%
16055243.037.5%
162011,5634.655.2%
16210372.943.2%
16218795.060.8%
16222985.355.1%
162265603.444.3%
16228312.725.8%
162296264.050.2%
16242875.157.5%
162491233.848.0%
16253238.469.6%
16259694.455.1%
162621774.855.9%
Source: Pennsylvania DEP radon test database (data.pa.gov), tests from 1986 to October 2026.

ZIP codes with the highest share of high results (100+ tests): 15686 (64.4%), 16262 (55.9%), 15774 (55.8%), 16201 (55.2%), 15690 (50.7%).

Results by community

Communities as written in the mailing address of the tested home, with at least 30 tests.

CommunityTestsMedian (pCi/L)At or above 4 pCi/L
Kittanning1,5584.655.3%
Leechburg6752.936.6%
Freeport6203.949.8%
Ford City5583.444.1%
Apollo4973.646.7%
Vandergrift2064.151.0%
Worthington1724.856.4%
Spring Church1606.564.4%
Rural Valley1233.848.0%
Shelocta1035.156.3%
Dayton965.355.2%
New Bethlehem854.956.5%
Cowansville795.060.8%
North Apollo703.545.7%
Templeton684.655.9%
Parker644.353.1%
Elderton519.474.5%
East Brady494.251.0%
Adrian353.045.7%
Ford Cliff302.826.7%
Source: Pennsylvania DEP radon test database (data.pa.gov).

Results by floor of the home

Radon usually comes from the ground, so levels are typically highest in the lowest part of the home. In Armstrong County:

Floor testedTestsMedian (pCi/L)At or above 4 pCi/L
Basement4,6604.353.3%
First Floor5721.927.6%
Slab On Grade1793.847.5%
Second Floor271.729.6%

Recent tests (2016 to 2026)

Looking only at the 2,346 tests since 2016, 47.0% were at or above 4 pCi/L and the median was 3.6 pCi/L, compared with 50.0% and 4 pCi/L for all years.

Radon mitigation in Armstrong County

  • Cost: the median reported cost of 50 mitigation systems installed in Armstrong County from 2022 to 2026 was $1,425.
  • Results: for systems installed since 2016, the median test before mitigation was 9.25 pCi/L and the median test after mitigation was 2 pCi/L.
  • Pennsylvania requires radon mitigation contractors to be certified by DEP. Find one in the DEP radon services directory or call 1-800-23-RADON.

Compare prices across states in our radon mitigation cost guide.

How to test your home in Armstrong County

  • Short-term kits are sold at hardware stores and by Pennsylvania-certified labs; PA DEP says they typically cost about $20 to $30.
  • Test the lowest lived-in level of the home with windows and doors closed.
  • For a home sale, use a DEP-certified radon tester.
  • If the result is 4 pCi/L or higher, the EPA recommends fixing the home; between 2 and 4 pCi/L, consider a fix.

More on Pennsylvania rules, contacts and every county’s EPA zone: Radon in Pennsylvania.

Frequently asked questions

Is radon a problem in Armstrong County?

50.0% of the 5,553 radon tests on record with PA DEP for Armstrong County were at or above 4 pCi/L, and the county is in EPA radon Zone 1. Any home can have high radon, so testing is the only way to know.

What is the average radon level in Armstrong County?

The median of all PA DEP test results in Armstrong County is 4 pCi/L. We use the median because a few very high readings would distort a simple average.

How much does radon mitigation cost in Armstrong County?

The median reported cost of 50 systems installed in Armstrong County from 2022 to 2026 was $1,425, according to PA DEP mitigation records.

Which ZIP codes in Armstrong County have the most radon?

Among ZIP codes with 100 or more tests, the highest shares of results at or above 4 pCi/L are in 15686 (64.4%), 16262 (55.9%), 15774 (55.8%).

Sources and method

Test statistics use the Pennsylvania DEP radon test database (about 3.4 million tests from 1986 to October 2026), limited to residential and unspecified buildings. Records can include repeat tests of the same home and some tests made after mitigation. Mitigation cost and before/after results come from the PA DEP radon mitigation system database. ZIP codes and communities with few tests are left out. Data retrieved November 2026.