Microbial
Escherichia coli (E. coli) in U.S. tap water
104 public water systems across 20 U.S. states report Escherichia coli (E. coli) in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
What it is
Escherichia coli — bacteria found in the gut of humans and animals.
Why it's regulated
Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.
Within the federal limit (90)
| Water system | Measured |
|---|---|
| Ansonia, CT 2024 annual report | 0 |
| Augusta, GA 2024 annual report | 0 |
| Bakersfield, CA 2024 annual report | 0 |
| Benedictine School, MD 2024 annual report | Not detected |
| Bethany, CT 2024 annual report | 0 |
| Branford, CT 2024 annual report | 0 |
| Burbank, CA 2024 annual report | 0 |
| Cedar Mhp, MD 2024 annual report | Not detected |
| Cedar Rapids, IA 2024 annual report | Not detected |
| Chandler, AZ 2024 annual report | 0 |
| Cheshire, CT 2024 annual report | 0 |
| Chicago, IL 2023 annual report | 0 |
| Chico, CA 2024 annual report | 0 |
| Chula Vista Otay, CA 2024 annual report | 0 |
| Chula Vista Sweetwater, CA 2024 annual report | 0 |
| City of Alpharetta, GA 2024 annual report | 0 |
| City of Hampton, VA 2024 annual report | 0 |
| City of Hemet, CA 2024 annual report | 0 |
| City of Menifee, CA 2024 annual report | 0 |
| City of Milton, GA 2024 annual report | 0 |
| City of Murrieta, CA 2024 annual report | 0 |
| City of Newport News, VA 2025 annual report | 0 |
| City of Perris, CA 2024 annual report | 0 |
| City of Poquoson, VA 2025 annual report | 0 |
| City of Poquoson, VA 2024 annual report | 0 |
| City of Robins, IA 2024 annual report | Not detected |
| City of Roswell, GA 2024 annual report | 0 |
| City of San Jacinto, CA 2024 annual report | 0 |
| City of Temecula, CA 2024 annual report | 0 |
| Corpus Christi, TX 2024 annual report | 0 |
| Daly City, CA 2024 annual report | 0 |
| Derby, CT 2024 annual report | 0 |
| East Haven, CT 2024 annual report | 0 |
| East Valley Service Area, CA 2024 annual report | 0 |
| El Cajon, CA 2024 annual report | 0 % |
| El Monte, CA 2024 annual report | 0 |
| Escondido, CA 2024 annual report | 0 |
| Fairfield, CA 2024 annual report | 0 |
| Fontana, CA 2024 annual report | 0 % |
| Frisco, TX 2024 annual report | 0 |
| Glenbrook Cove Subdivision of Marion, IA 2024 annual report | Not detected |
| Hamden, CT 2024 annual report | 0 |
| Hampton, VA 2025 annual report | 0 |
| Hayward, CA 2024 annual report | Not detected |
| Hesperia, CA 2024 annual report | 0 |
| High Point, NC 2024 annual report | 0 |
| Inglewood, CA 2023 annual report | 0 % |
| James City County, VA 2025 annual report | 0 |
| James City County, VA 2024 annual report | 0 |
| Johns Creek, GA 2024 annual report | 0 |
Showing 50 of 90. The full list is in the JSON API.
Frequently asked
+What is Escherichia coli (E. coli)?
Escherichia coli — bacteria found in the gut of humans and animals. Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.
+What is the federal limit for Escherichia coli (E. coli) in drinking water?
The federal MCL for Escherichia coli (E. coli) is 0 . The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have Escherichia coli (E. coli) over the federal limit?
Zero of the 104 public water systems in The Water Map dataset currently report Escherichia coli (E. coli) at or above its federal limit.
+How can I check if Escherichia coli (E. coli) is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including Escherichia coli (E. coli).
See Escherichia coli (E. coli) on the map
Color-coded by status across the whole country.
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