Chloride in Idaho well water
In Idaho, chloride was detected in 99% of 9,138 tested private well samples.
Chloride mainly comes from road salt and water softener discharge. Above 250 mg/L water tastes salty and corrodes plumbing. Rising chloride in a well usually means road salt is reaching the aquifer.
Check your chloride number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Getting it fixed
Book a free in-home water test with a licensed local company, or see the treatment guide for what removes chloride.
By county, from individual samples
Public monitoring samples against the EPA limit; counties with at least 30 samples.
| County | Samples | Detected | Above EPA limit | Median | Highest |
|---|---|---|---|---|---|
| Fremont | 248 | 100% | no limit | 5.97 | 304 mg/L |
| Gooding | 162 | 100% | no limit | 19.9 | 70 mg/L |
| Franklin | 59 | 100% | no limit | 37.3 | 414 mg/L |
| Cassia | 247 | 100% | no limit | 43.8 | 1,250 mg/L |
| Bingham | 248 | 100% | no limit | 14 | 160 mg/L |
| Gem | 196 | 100% | no limit | 3.6 | 49.4 mg/L |
| Bear Lake | 114 | 100% | no limit | 20.4 | 237 mg/L |
| Elmore | 295 | 100% | no limit | 12.1 | 370 mg/L |
| Bonneville | 187 | 100% | no limit | 13 | 280 mg/L |
| Ada | 700 | 100% | no limit | 7.3 | 155 mg/L |
| Butte | 96 | 100% | no limit | 15 | 290 mg/L |
| Camas | 59 | 100% | no limit | 2.05 | 10.2 mg/L |
| Blaine | 144 | 100% | no limit | 3.31 | 23 mg/L |
| Caribou | 183 | 100% | no limit | 15 | 191 mg/L |
| Jefferson | 208 | 100% | no limit | 12 | 470 mg/L |
- Hollister CCD, Twin Falls County100% detected of 137
- Kimberly CCD, Twin Falls County100% detected of 94
- Filer CCD, Twin Falls County100% detected of 90
- Cottonwood CCD, Idaho County100% detected of 34
- Bruneau CCD, Owyhee County100% detected of 36
- Nez Perce CCD, Idaho County100% detected of 35
- Murphy CCD, Owyhee County100% detected of 40
- Grand View CCD, Owyhee County100% detected of 60
- Fort Hall CCD, Bannock County100% detected of 37
- Inkom CCD, Bannock County100% detected of 33
- Pocatello CCD, Bannock County100% detected of 101
- Marsing CCD, Owyhee County100% detected of 41
- Glenns Ferry CCD, Elmore County100% detected of 63
- Mountain Home CCD, Elmore County100% detected of 219
- Mink Creek CCD, Franklin County100% detected of 33
- Ashton CCD, Fremont County100% detected of 92
- Island Park CCD, Fremont County100% detected of 98
- St. Anthony CCD, Fremont County100% detected of 56
- Buhl CCD, Twin Falls County100% detected of 119
- Murtaugh CCD, Twin Falls County100% detected of 37
Sources
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. chloride counts and shares are listed on each county and town page with their sources.