Radon in Idaho well water
In Idaho, radon was detected in 100% of 1,617 tested private well samples.
Radon is a radioactive gas released from bedrock into well water. It escapes into household air during showers and washing, where inhaling it raises lung cancer risk. EPA has no enforceable water MCL; New Hampshire recommends treatment above 2,000 pCi/L, and many states use 4,000 pCi/L.
Check your radon number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your Idaho well for radon
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Getting it fixed
Book a free in-home water test with a licensed local company, or see the treatment guide for what removes radon.
Where to get a well tested for radon in Idaho: certified labs, state programs and prices.
By county, from individual samples
Public monitoring samples against the EPA limit; counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Twin Falls | no limit | 65 | 100% | 320 | 4,430 pCi/L |
| Bannock | no limit | 34 | 100% | 482 | 1,900 pCi/L |
| Bingham | no limit | 62 | 100% | 297 | 900 pCi/L |
| Blaine | no limit | 34 | 100% | 875 | 2,610 pCi/L |
| Bonner | no limit | 55 | 100% | 650 | 3,930 pCi/L |
| Butte | no limit | 59 | 100% | 170 | 1,200 pCi/L |
| Canyon | no limit | 106 | 100% | 480 | 3,620 pCi/L |
| Cassia | no limit | 35 | 100% | 490 | 3,880 pCi/L |
| Custer | no limit | 54 | 100% | 1,480 | 8,000 pCi/L |
| Elmore | no limit | 33 | 100% | 480 | 1,900 pCi/L |
| Minidoka | no limit | 92 | 100% | 160 | 1,000 pCi/L |
| Ada | no limit | 353 | 100% | 600 | 2,800 pCi/L |
| Jefferson | no limit | 41 | 100% | 230 | 1,390 pCi/L |
| Kootenai | no limit | 30 | 100% | 759 | 2,940 pCi/L |
| Latah | no limit | 30 | 100% | 465 | 8,040 pCi/L |
- Howe CCD, Butte County100% detected of 36
- Nampa CCD, Canyon County100% detected of 41
- Stanley CCD, Custer County100% detected of 35
- Mud Lake-Hamer CCD, Jefferson County100% detected of 34
- Eagle CCD, Ada County100% detected of 57
- Minidoka CCD, Minidoka County100% detected of 33
- Boise City CCD, Ada County100% detected of 227
- Orchard CCD, Ada County100% detected of 40
- Jerome CCD, Jerome County97% detected of 38
Sources
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. radon counts and shares are listed on each county and town page with their sources.