Radon levels in Pinal County, Arizona

LowEPA Zone 2

Predicted long-term basement average of 1.7 pCi/L (model estimate) across 25 ZIP codes - close to the US average of 1.8, close to the Arizona average of 1.7. Ranked #10 of 15 Arizona counties.

Test Pinal County, AZ once anyway - radon varies house to house

The predicted basement average here is 1.7 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.

We may earn a commission from Amazon at no extra cost to you.

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.

1.7 ± 0.07

pCi/L predicted basement mean (model SD)

0.9 ± 0.09

pCi/L predicted upstairs (above-ground) mean

1.4-2.0

range of ZIP-level basement predictions in the county

What this means for Pinal

The typical Pinal County home is predicted below 2 pCi/L, the lowest band. That is the best case an area can show - but it describes the average house, and the ZIP-level predictions within the county still span 1.4 to 2.0 pCi/L.

Note that the EPA classifies Pinal County as Zone 2 while the newer model predicts 1.7 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 Arizona counties: Pima County (1.7), Mohave County (1.7), Maricopa County (1.7), La Paz County (1.7). The state's highest is Coconino County at 2.3 pCi/L.

ZIP codes in Pinal County

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

ZIPBasementUpstairsGrade
851221.8 ± 0.071.0Low
851421.7 ± 0.070.9Low
851401.7 ± 0.071.0Low
851431.7 ± 0.061.0Low
851381.8 ± 0.061.1Low
851321.8 ± 0.070.9Low
851201.5 ± 0.070.5Low
851191.4 ± 0.080.3Low
851311.8 ± 0.070.8Low
851391.9 ± 0.071.0Low
857391.9 ± 0.061.2Low
851281.8 ± 0.070.8Low
851181.8 ± 0.081.3Low
851231.8 ± 0.070.9Low
856581.7 ± 0.051.1Low
851942.0 ± 0.060.9Low
851931.9 ± 0.070.8Low
856231.9 ± 0.071.1Low
856311.8 ± 0.071.0Low
851732.0 ± 0.061.2Moderate
851371.9 ± 0.061.0Low
851922.0 ± 0.071.0Low
851451.9 ± 0.071.0Low
856181.8 ± 0.071.0Low
851721.7 ± 0.071.0Low

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.

Pinal County radon questions

Is radon high in Pinal County, Arizona?
Low. The model predicts a long-term basement average of 1.7 pCi/L in Pinal County (close to the US average of 1.8 and close to the Arizona average of 1.7). That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Ranked 10 of 15 Arizona counties.
Should I test for radon in Pinal County?
Yes, once. The EPA recommends testing every home regardless of area, and the model's ZIP-level predictions in Pinal County already range from 1.4 to 2.0 pCi/L. A short-term kit costs little and settles the question for your house.
What does EPA Radon Zone 2 mean for Pinal County?
Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and classifies whole counties. The newer model's predicted average of 1.7 pCi/L does not line up with Zone 2, 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 Pinal County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Arizona 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.

← All Arizona counties · How to test · Radon in a home sale · Methodology