Disinfection byproducts
NDMA in U.S. tap water
29 public water systems across 3 U.S. states report NDMA in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
Within the federal limit (26)
| Water system | Measured |
|---|---|
| Alameda, CA 2024 annual report | 3.9 ng/L |
| Albany, CA 2024 annual report | 3.9 ng/L |
| Berkeley, CA 2024 annual report | 3.9 ng/L |
| Castro Valley, CA 2024 annual report | 3.9 ng/L |
| Crockett, CA 2024 annual report | 3.9 ng/L |
| El Cerrito, CA 2024 annual report | 3.9 ng/L |
| El Sobrante, CA 2024 annual report | 3.9 ng/L |
| Emeryville, CA 2024 annual report | 3.9 ng/L |
| Hayward, CA 2024 annual report | 3.9 ng/L |
| Hercules, CA 2024 annual report | 3.9 ng/L |
| Kensington, CA 2024 annual report | 3.9 ng/L |
| Lafayette, CA 2024 annual report | 3.9 ng/L |
| Moraga, CA 2024 annual report | 3.9 ng/L |
| Oakland, CA 2024 annual report | 3.9 ng/L |
| Orinda, CA 2024 annual report | 3.9 ng/L |
| Piedmont, CA 2024 annual report | 3.9 ng/L |
| Pinole, CA 2024 annual report | 3.9 ng/L |
| Richmond, CA 2024 annual report | 3.9 ng/L |
| Rodeo, CA 2024 annual report | 3.9 ng/L |
| San Leandro, CA 2024 annual report | 3.9 ng/L |
| San Lorenzo, CA 2024 annual report | 3.9 ng/L |
| San Pablo, CA 2024 annual report | 3.9 ng/L |
| San Diego, CA 2023 annual report | 1.3 ng/L |
| Costa Mesa, CA 2024 annual report | Not detected ng/L |
| El Cajon, CA 2024 annual report | Not detected ng/L |
| Pomona, CA 2024 annual report | Not detected ng/L |
Frequently asked
+What is NDMA?
NDMA is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+What is the federal limit for NDMA in drinking water?
The federal NL for NDMA is 10 ng/L. 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 NDMA over the federal limit?
Zero of the 29 public water systems in The Water Map dataset currently report NDMA at or above its federal limit.
+How can I check if NDMA 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 NDMA.