E. coli in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
E. coli is a fecal indicator organism. Its presence indicates direct fecal contamination and is a serious health concern. E. coli can cause severe gastrointestinal illness and certain strains (like O157:H7) can cause kidney failure, especially in children.
📍 Sources in Water
Enters water from human sewage, animal waste, and stormwater runoff. Detection indicates a treatment failure, damaged distribution pipes, or contaminated source water. E. coli violations require immediate public notification.
✅ What To Do
Follow any boil water advisory or "do not drink" notice immediately. Use bottled water until the advisory is lifted. E. coli violations require corrective action and are among the most serious water quality events.
Check your tap water for E. coli
Search your ZIP code to see if your water system has had E. coli violations, plus lead testing results and an overall safety grade.
Search your ZIP code →Data from the EPA's Safe Drinking Water Information System (SDWIS). MCLs reflect minimum federal standards; some contaminants may pose health risks below these thresholds.