ZIP Code 83868
Shoshone County, Idaho — Smelterville
What This Means
Shoshone County, Idaho is in EPA Radon Zone 1, the highest risk category. The EPA predicts average indoor radon levels greater than 4.0 pCi/L in this area — above the EPA action level. The EPA strongly recommends testing all homes in Zone 1 areas. If your home tests above 4.0 pCi/L, a radon mitigation system can reduce levels by up to 99%.
What You Should Do
EPA Zone Details
| ZIP Code | 83868 |
| County | Shoshone |
| City | Smelterville |
| State | Idaho (ID) |
| EPA Radon Zone | Zone 1 — High |
| Predicted Indoor Radon | >4 pCi/L |
Source: EPA Map of Radon Zones
Radon & Your Basement in Shoshone County
Shoshone County is in EPA Zone 1, the highest risk category. Basements and ground-level rooms in this area are very likely to have elevated radon concentrations. If your home has a basement, it should be your first testing location.
Radon concentrations are typically highest in the lowest level of a home. However, radon does not stay confined to the basement — it migrates to upper floors through stairways, HVAC ducts, and gaps in flooring. Even if your basement is unfinished or rarely used, elevated radon there can affect the air quality on your main living floors. Always test on the lowest livable level.
Shoshone County Radon Map
Counties colored by EPA radon zone. Red = Zone 1 (high), Orange = Zone 2 (moderate), Green = Zone 3 (low).
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Frequently Asked Questions
What is the radon risk level for ZIP code 83868?
ZIP code 83868 is in Shoshone County, Idaho, which is classified as EPA Radon Zone 1 (high risk). The predicted average indoor radon level is >4 pCi/L.
Should I test for radon in 83868?
Yes. The EPA recommends testing all homes for radon regardless of zone. Since 83868 is in a high-risk Zone 1 area, testing is especially important.
What county is ZIP code 83868 in?
ZIP code 83868 is in Shoshone County, Idaho (ID).
Is it safe to live in ZIP code 83868?
ZIP code 83868 is in a high-risk EPA Zone 1 area. While this does not mean every home has dangerous radon levels, the probability is elevated. The EPA strongly recommends testing all homes in this zone. With proper mitigation, homes in high-risk areas can achieve safe radon levels.
Does radon in the basement affect upper floors in Shoshone County?
Yes. Radon enters through the foundation and can migrate to upper floors through stairways, HVAC systems, and structural gaps. While concentrations are typically highest at the lowest level, upper floors in Shoshone County homes can still have measurable radon. Always test on the lowest livable floor.
How much does radon mitigation cost in Idaho?
In Idaho, radon mitigation systems typically cost between $800 and $2,500 depending on home size, foundation type, and local labor rates. The most common system (sub-slab depressurization) averages $1,000-$1,500. The fan lasts 10-15 years and costs $150-$300 to replace. Some states offer financial assistance programs for radon mitigation.