Radon Mitigation in Spokane Valley, WA

Under most of Spokane Valley lies open flood gravel hundreds of feet deep, the same gravel that holds the aquifer. It moves soil gas as easily as water, and the state's test data show it: in most Valley neighborhoods, half or more of reported radon tests come back at or above the EPA action level.

Or call (509) 278-2215

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

How it works in Spokane Valley

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 Valley 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 Valley

The Valley's open gravel usually works in your favor: suction spreads far under a slab, so a single suction point often covers a whole floor. Split-levels and additions on a separate slab may need a point of their own. Which utility powers the fan depends on your parcel; the city names four.

Starting prices include the electrical permit and the post-mitigation test. Bold: systems common in Spokane Valley 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 Valley

Spokane Valley 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.

Why radon runs high in Spokane Valley

The Valley floor is a channel two to three miles wide that Ice Age floods filled with gravel, in the center more than 600 feet deep. In the main flood channel the deposits come in layers of cobbles and boulders with little silt or clay between them. That is why the Valley has almost no surface streams: water sinks straight in. Soil gas moves through the same open spaces.

U.S. Geological Survey well logs find fine-grained layers only along the valley edges and near the outlets of Liberty, Newman and Hauser lakes. Under most of the city there is nothing to slow radon on its way to a basement floor, and the water table lies up to about 200 feet down, so a deep column of dry gravel sits under every house.

The hills along the south and east edges are different ground: old schist and gneiss with small granite bodies, flanked by Latah Formation clay that was once mined south of Opportunity and Veradale. Homes on those slopes can test differently from homes on the flat.

of Ice Age flood gravel under the central Spokane Valley, open enough that streams sink into it³

Spokane Valley questions