Is radon high in Grays Harbor County, Washington?

Low. The model predicts a long-term basement average of 1.5 pCi/L in Grays Harbor County (about 17% below the US average of 1.8 and close to the Washington average of 1.6). That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Ranked 29 of 39 Washington counties.

Should I test for radon in Grays Harbor County?

Yes, once. The EPA recommends testing every home regardless of area, and the model's ZIP-level predictions in Grays Harbor County already range from 1.5 to 1.7 pCi/L. A short-term kit costs little and settles the question for your house.

What does EPA Radon Zone 3 mean for Grays Harbor 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 Grays Harbor County?

A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Washington 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.

Radon levels in Grays Harbor County, Washington

LowEPA Zone 3

Predicted long-term basement average of 1.5 pCi/L (model estimate) across 16 ZIP codes - about 17% below the US average of 1.8, close to the Washington average of 1.6. Ranked #29 of 39 Washington counties.

Test Grays Harbor County, WA once anyway - radon varies house to house

The predicted basement average here is 1.5 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.

Get a short-term test kit →Or track it with a continuous monitor

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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.

1.5 ± 0.06

pCi/L predicted basement mean (model SD)

0.8 ± 0.09

pCi/L predicted upstairs (above-ground) mean

1.5-1.7

range of ZIP-level basement predictions in the county

What this means for Grays Harbor

The typical Grays Harbor 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 1.5 to 1.7 pCi/L.

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

Comparable Washington counties: Skagit County (1.5), Clallam County (1.5), Pacific County (1.5), Whatcom County (1.5). The state's highest is Pend Oreille County at 3.1 pCi/L.

ZIP codes in Grays Harbor County

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

ZIP	Basement	Upstairs	Grade
98520	1.5 ± 0.06	0.8	Low
98550	1.5 ± 0.07	0.8	Low
98541	1.6 ± 0.06	0.8	Low
98563	1.5 ± 0.06	0.9	Low
98569	1.6 ± 0.07	0.7	Low
98557	1.6 ± 0.07	0.8	Low
98595	1.5 ± 0.07	0.7	Low
98568	1.5 ± 0.05	0.8	Low
98537	1.5 ± 0.06	0.9	Low
98587	1.5 ± 0.07	0.7	Low
98552	1.5 ± 0.07	0.8	Low
98571	1.5 ± 0.07	0.7	Low
98535	1.6 ± 0.07	0.7	Low
98526	1.6 ± 0.07	0.8	Low
98575	1.7 ± 0.07	0.9	Low
98536	1.6 ± 0.06	0.6	Low

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.

Grays Harbor County radon questions

Is radon high in Grays Harbor County, Washington?: Low. The model predicts a long-term basement average of 1.5 pCi/L in Grays Harbor County (about 17% below the US average of 1.8 and close to the Washington average of 1.6). That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Ranked 29 of 39 Washington counties.
Should I test for radon in Grays Harbor County?: Yes, once. The EPA recommends testing every home regardless of area, and the model's ZIP-level predictions in Grays Harbor County already range from 1.5 to 1.7 pCi/L. A short-term kit costs little and settles the question for your house.
What does EPA Radon Zone 3 mean for Grays Harbor 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 Grays Harbor County?: A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Washington 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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