Radon levels in Clackamas County, Oregon

LowEPA Zone 3

Predicted long-term basement average of 1.6 pCi/L (model estimate) across 24 ZIP codes - close to the US average of 1.8, close to the Oregon average of 1.7. Ranked #30 of 36 Oregon counties.

Test Clackamas County, OR once anyway - radon varies house to house

The predicted basement average here is 1.6 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.

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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.

1.6 ± 0.07

pCi/L predicted basement mean (model SD)

0.9 ± 0.09

pCi/L predicted upstairs (above-ground) mean

0.9-2.0

range of ZIP-level basement predictions in the county

What this means for Clackamas

The typical Clackamas 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 0.9 to 2.0 pCi/L.

The 1993 EPA zone (3) and the 2001-2021 model agree for Clackamas. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable Oregon counties: Curry County (1.5), Lane County (1.6), Clatsop County (1.6), Columbia County (1.6). The state's highest is Union County at 2.5 pCi/L.

ZIP codes in Clackamas County

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

ZIPBasementUpstairsGrade
970451.4 ± 0.070.7Low
972221.8 ± 0.061.2Low
972671.7 ± 0.071.2Low
970681.5 ± 0.070.8Low
970860.9 ± 0.140.5Low
970351.9 ± 0.091.1Low
970131.7 ± 0.081.0Low
970701.5 ± 0.060.8Low
970151.5 ± 0.070.6Low
970341.6 ± 0.060.8Low
970551.8 ± 0.081.1Low
970381.7 ± 0.070.9Low
970271.8 ± 0.061.0Low
970891.4 ± 0.070.7Low
970231.5 ± 0.070.8Low
970091.7 ± 0.070.9Low
970041.6 ± 0.060.8Low
970221.5 ± 0.070.9Low
970421.6 ± 0.060.8Low
970171.6 ± 0.060.9Low
970671.8 ± 0.070.9Low
970491.8 ± 0.080.8Low
970111.8 ± 0.081.0Low
970282.0 ± 0.080.9Low

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.

Clackamas County radon questions

Is radon high in Clackamas County, Oregon?
Low. The model predicts a long-term basement average of 1.6 pCi/L in Clackamas County (close to the US average of 1.8 and close to the Oregon average of 1.7). That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Ranked 30 of 36 Oregon counties.
Should I test for radon in Clackamas County?
Yes, once. The EPA recommends testing every home regardless of area, and the model's ZIP-level predictions in Clackamas County already range from 0.9 to 2.0 pCi/L. A short-term kit costs little and settles the question for your house.
What does EPA Radon Zone 3 mean for Clackamas County?
Zone 3 - low potential (< 2 pCi/L). The zone map dates from 1993 and classifies whole counties. The 2001-2021 model agrees with the zone here. Neither replaces a test of your own home.
How much does radon mitigation cost in Clackamas County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Oregon 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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