Is radon high in Walsh County, North Dakota?

High. The model predicts a long-term basement average of 4.2 pCi/L in Walsh County (about 2.3× the US average of 1.8 and about 1.3× the North Dakota average of 3.3). That is at or above the EPA action level of 4 pCi/L, so the typical home here would qualify for mitigation. Ranked 3 of 53 North Dakota counties.

Should I test for radon in Walsh County?

Yes, soon. With a predicted average of 4.2 pCi/L and at least one ZIP predicted at 4.5, many homes in Walsh County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.

What does EPA Radon Zone 1 mean for Walsh County?

Zone 1 - highest potential (predicted average > 4 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 Walsh County?

A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; North Dakota 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 Walsh County, North Dakota

HighEPA Zone 1

Predicted long-term basement average of 4.2 pCi/L (model estimate) across 11 ZIP codes - about 2.3× the US average of 1.8, about 1.3× the North Dakota average of 3.3. Ranked #3 of 53 North Dakota counties.

Test Walsh County, ND now - and consider a continuous monitor

The model predicts a long-term basement average of 4.2 pCi/L here, at or above the EPA action level of 4. Homes in the same ZIP still vary widely, so a real test is the only way to know your number. A continuous digital monitor shows how your level swings with weather and season, which matters when you're near the action level.

Get a continuous radon monitor →Or start with a short-term test kit

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

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.

4.2 ± 0.07

pCi/L predicted basement mean (model SD)

2.6 ± 0.08

pCi/L predicted upstairs (above-ground) mean

3.5-4.5

range of ZIP-level basement predictions in the county

What this means for Walsh

The typical home in Walsh County is predicted to sit at or above the EPA action level of 4 pCi/L in the basement. In practice that means a large share of houses here would qualify for mitigation if tested, and buyers routinely ask for radon tests in North Dakota transactions.

The 1993 EPA zone (1) and the 2001-2021 model agree for Walsh. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable North Dakota counties: Foster County (4.2), Ransom County (4.2), Ramsey County (4.1), Emmons County (4.1). The state's highest is Grand Forks County at 4.4 pCi/L.

ZIP codes in Walsh County

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

ZIP	Basement	Upstairs	Grade
58237	4.3 ± 0.07	2.9	High
58270	4.2 ± 0.11	2.4	High
58261	4.4 ± 0.08	2.5	High
58243	4.2 ± 0.06	2.4	High
58227	3.8 ± 0.06	2.3	Moderate
58231	4.0 ± 0.06	2.2	Moderate
58210	3.8 ± 0.06	2.2	Moderate
58233	4.0 ± 0.07	2.3	Moderate
58273	3.7 ± 0.07	2.3	Moderate
58250	3.5 ± 0.07	2.1	Moderate
58229	3.6 ± 0.07	2.0	Moderate

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.

Walsh County radon questions

Is radon high in Walsh County, North Dakota?: High. The model predicts a long-term basement average of 4.2 pCi/L in Walsh County (about 2.3× the US average of 1.8 and about 1.3× the North Dakota average of 3.3). That is at or above the EPA action level of 4 pCi/L, so the typical home here would qualify for mitigation. Ranked 3 of 53 North Dakota counties.
Should I test for radon in Walsh County?: Yes, soon. With a predicted average of 4.2 pCi/L and at least one ZIP predicted at 4.5, many homes in Walsh County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.
What does EPA Radon Zone 1 mean for Walsh County?: Zone 1 - highest potential (predicted average > 4 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 Walsh County?: A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; North Dakota 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 North Dakota counties · How to test · Radon in a home sale · Methodology