E. coli in well water
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.
- EPA limit
- 0 MPN/100mL (EPA MCL: any confirmed presence (40 CFR 141.63))
How to test
Use a state-certified lab and a proper sampling bottle; hardware-store strips cannot measure e. coli at the levels that matter. Collect from the kitchen tap before any treatment, and again after treatment if you install it.
How to treat
- Shock chlorination and fix the well cap or casing
- UV disinfection whole-house
- Chlorination system