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Nitrate Nitrite in U.S. tap water
153 public water systems across 19 U.S. states report Nitrate Nitrite in their annual Consumer Confidence Report. 2 sit at or above the federal limit.
At or above the federal limit (2)
| Water system | Measured | vs. limit |
|---|---|---|
| Richardson, TX 2024 annual report | 211 mg/L | 21.1× the limit |
| La Canada Irrigation Dist. — La Canada, Ca, CA 2020 annual report | 10 mg/L | 1.0× the limit |
Approaching the limit (6)
| Water system | Measured | vs. limit |
|---|---|---|
| Chapel Hill Water System, MD 2024 annual report | 9.2 mg/L | 0.9× the limit |
| Sleepy Valley Water Company — Santa Clarita, Ca, CA 2021 annual report | 9.1 mg/L | 0.9× the limit |
| Sleepy Valley Water Company — Santa Clarita, Ca, CA 2020 annual report | 9.1 mg/L | 0.9× the limit |
| Boh Nak Mhp, MD 2024 annual report | 8.3 mg/L | 0.8× the limit |
| Loma Linda, City of — Loma Linda, Ca, CA 2023 annual report | 0.47–8.2 mg/L | 0.8× the limit |
| Gaither Manor Apartments, MD 2024 annual report | 8.1 mg/L | 0.8× the limit |
Within the federal limit (145)
Showing 50 of 145. The full list is in the JSON API.
Frequently asked
+What is Nitrate Nitrite?
Nitrate Nitrite is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+What is the federal limit for Nitrate Nitrite in drinking water?
The federal MCL for Nitrate Nitrite is 10 mg/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 Nitrate Nitrite over the federal limit?
2 of the 153 public water systems on The Water Map report Nitrate Nitrite at or above its federal limit, spanning 19 U.S. states. The full list is on this page.
+How can I check if Nitrate Nitrite 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 Nitrate Nitrite.