Total Coliform in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
Total coliform bacteria are used as an indicator of water quality. Their presence may indicate contamination with human or animal fecal material that could contain disease-causing organisms, leading to stomach and intestinal illness.
📍 Sources in Water
Coliform bacteria are naturally present in the environment and in animal digestive systems. They enter water from surface water runoff, treatment failures, and distribution system contamination (main breaks, pressure losses).
✅ What To Do
If your utility has issued a boil water notice, boil water vigorously for 1 minute before drinking or use bottled water. If a violation was reported but no boil notice issued, contact your utility to understand the specific situation.
Check your tap water for Total Coliform
Search your ZIP code to see if your water system has had Total Coliform 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.