Radon Mitigation in Spokane County, WA

Spokane County stands out in Washington's radon data. In the 1991–92 state survey its homes had the highest average of any Washington county in the survey, and of 18,518 tests reported from 1990 through 2020, 47.0% reached the EPA action level. The county also takes in farm towns, lake communities and well-water country, and their numbers differ widely.

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48-hour test from $195 · Systems from $1,295 · Post-mitigation test included

How it works in Spokane County

1. STEP 1
   Test

   A 48-hour continuous monitor in your lowest living level, under closed-house conditions. Report the same day it comes out.

2. STEP 2
   Look and quote

   We check the foundation, run a suction test and plan the pipe route for Spokane County winters. You get a fixed price in writing.

3. STEP 3
   Install

   Most systems take one day: suction point, sealing, fan, manometer and the electrical permit.

4. STEP 4
   Re-test

   A post-mitigation test at least 24 hours after the fan starts shows the new number. The guarantee is below 4.0 pCi/L.

Radon mitigation cost in Spokane County

Five electric utilities serve nearly all homes in Spokane County: Avista, Inland Power & Light, Modern Electric Water, Vera Water & Power and the City of Cheney. Which one powers your fan depends on the address, and the most expensive rate is more than twice the cheapest. The system price itself depends on the foundation and the pipe route, not on the town.

Starting prices include the electrical permit and the post-mitigation test. Bold: systems common in Spokane County homes. Estimate your system →

for a typical 60-watt fan running around the clock, depending on which utility serves your address. Energy charge only, at 2026 residential rates.

A 20-watt fan costs about a third of that, a 90-watt fan half again as much.

Permits and local rules in Spokane County

Spokane County at a glance

Area figures describe the neighborhood, not your home. Only a test tells you your number. Sources are listed at the end of this page.

What drives radon across Spokane County

Spokane County spans three landscapes. North of the Spokane and Little Spokane rivers rise the forested Okanogan Highlands, and USGS geologists noted numerous uranium occurrences in the granitic hills just north of the city. The city and its eastern suburbs sit on highly permeable glacial outwash, and a study cited by USGS found as many as 70 percent of homes over 4 pCi/L in some townships near Spokane, with local readings up to 200 pCi/L. To the south lie the edge of the Palouse and the scabland canyons.

Even the basalt country south and west of Spokane isn't low by default. The basalt itself holds little uranium, but USGS still measured moderately elevated uranium there, because the flood, lake and wind deposits on top came largely from the uranium-richer rocks of northeastern Washington and northern Idaho. No part of the county can be written off before a test.

The state's census-tract data show how wide the spread is. Across 102 Spokane County tracts with enough tests, the share at or above 4.0 pCi/L runs from 9.8% in a tract in ZIP 99001 on the West Plains to 79.1% in one in ZIP 99212 in the Valley, and 46 tracts are at 50% or higher. The 1991–92 survey used short screening tests on the lowest level of each home, so its numbers and today's are not directly comparable.

of 449 county homes tested above 4 pCi/L in 1991–92, the highest share of any Washington county surveyed¹

Spokane County questions