E. coli in Drinking Water
Microbial · MCL: 0 presence · 0 systems exceeding limit
Overview
E. coli is regulated under the Safe Drinking Water Act with an MCL of 0 presence. The EPA Safe Drinking Water program sets and enforces the maximum contaminant levels shown here.
Health Effects
Exposure to E. coli above the MCL of 0 presence may cause adverse health effects. Consult EPA fact sheets for detailed information.
Sources of Contamination
E. coli can enter drinking water from natural deposits, industrial discharges, or other sources.
Treatment & Removal
Treatment methods for E. coli include activated carbon filtration, reverse osmosis, and specialized media.
How to Remove E. coli From Water
These filtration methods are effective for reducing E. coli in drinking water:
| Filter Method | Effectiveness | Cost Range | Certification |
|---|---|---|---|
| UV Disinfection | 99.99% inactivation | $150-500 (point-of-use) | NSF/ANSI 55 (Class A) |
| Reverse Osmosis (RO) | 99%+ removal | $200-500 (under-sink) | NSF/ANSI 58 |
| Ceramic Filters | 99.99% removal | $30-150 | NSF/ANSI 53 P231 |
UV Disinfection, details
Most effective for bacteria. Must be Class A rated for microbiological purification.
Reverse Osmosis (RO), details
Physical barrier removes bacteria. Must be maintained to prevent biofilm.
Ceramic Filters, details
Pore size of 0.2 microns or smaller blocks bacteria. Gravity-fed options available.
Water Systems with E. coli Detected
Chicago
Chicago, Illinois
San Antonio Water System
San Antonio, Texas
City of Baltimore
Baltimore, Maryland
Jea Major Grid
Jacksonville, Florida
Aqua Pa Main System
Bryn Mawr, Pennsylvania
Mesa City Of
Mesa, Arizona
Salt Lake City Water System
Salt Lake City, Utah
Madison Water Utility
Madison, Wisconsin
Nj American Water - Western
Delran, New Jersey
Jersey City Mua
Hoboken, New Jersey
Emerald Coast Utilities Authority (ecua)
Pensacola, Florida
Wildwood City Water Department
Rio Grande, New Jersey
Tallahassee, City Of
Tallahassee, Florida
Springfield Water and Sewer Commission
Springfield, Massachusetts
Olathe, City Of
Olathe, Kansas
Waterbury Water Department
Waterbury, Connecticut
St George City Water System
St George City, Utah
Cicero
Cicero, Illinois
City of Olive Branch
Olive Branch, Mississippi
Roswell Municipal Water System
Roswell, New Mexico
Berkeley County Pswd-Potomac River
Martinsburg, West Virginia
Frequently Asked Questions
E. coli has been detected in 0 water systems that exceed the EPA maximum contaminant level (MCL) of 0 presence, affecting approximately 0 people. Check your local water system's annual Consumer Confidence Report or search by ZIP code on this site.
Exposure to E. coli above the MCL of 0 presence may cause adverse health effects. Consult EPA fact sheets for detailed information.
Effective filtration methods for E. coli include UV Disinfection, Reverse Osmosis (RO), Ceramic Filters. Look for filters certified to NSF/ANSI standards for E. coli removal. See the detailed comparison table above for effectiveness ratings and cost ranges.
The EPA Maximum Contaminant Level (MCL) for E. coli is 0 presence. The MCL Goal (MCLG), the level with no known health risk, is 0 presence. Water systems must test regularly and notify customers if levels exceed the MCL.