Well Water Nerd

E. coli in Idaho well water

In Idaho, <1% of 5,473 tested private well samples exceeded the EPA limit for E. coli (0 MPN/100mL).

E. coli in a well means fecal contamination from septic systems, animals or surface water entering the well. It can cause serious gastrointestinal illness. Any detection is a failure.

Check your E. coli 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 E. coli.

By county, from individual samples

Public monitoring samples against the EPA limit (0 MPN/100mL); counties with at least 30 samples.

CountySamplesDetectedAbove EPA limitMedianHighest
Butte385%5%0190 MPN/100mL
Teton1433%3%05 MPN/100mL
Blaine1373%3%055 MPN/100mL
Fremont3133%3%0200 MPN/100mL
Canyon592<1%<1%051 MPN/100mL
Elmore381<1%<1%01 MPN/100mL
Caribou1000%0%00 MPN/100mL
Bingham1510%0%00 MPN/100mL
Bannock2160%0%00 MPN/100mL
Boundary780%0%00 MPN/100mL
Bonneville1040%0%00 MPN/100mL
Camas390%0%00 MPN/100mL
Benewah1160%0%00 MPN/100mL
Bonner2240%0%00 MPN/100mL
Boise600%0%00 MPN/100mL

Sources

  • Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. E. coli counts and shares are listed on each county and town page with their sources.