What Nitrate-Nitrite is, and why it's regulated
What the EPA limit means
10000 µg/L
Maximum Contaminant Level — the enforceable ceiling a supplier must stay under.
10000 µg/L
Health goal (MCLG) — the level with no known health effect. It is a goal, not a legal limit, and is often zero for carcinogens.
SYR4
Where these measurements come from. Hover the tag for the EPA programme and years.
Where Nitrate-Nitrite was found
The water suppliers reporting the highest levels, worst first. For lead and copper that is the 90th-percentile result the action level is written against; for Six-Year Review data, the 95th percentile of each system's samples.
| Supplier | City | State | Level vs EPA limit |
|---|---|---|---|
| Cal Am - Lincoln Oaks | Sacramento | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Leisure Lake Mobile Estates | — | AZ | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Center Water Co | Lucerne Valley | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Sbdno County Service Area 70 Cedar Glen | San Bernardino | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Mountain House | Mountain House | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Vacaville | Vacaville | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Pico Rivera - City, Water Dept. | Pico Rivera | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Fairfield | Fairfield | CA | 1000000 µg/L 10000% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Maywood Mutual Water Co. #1 | Huntington Park | CA | 994500 µg/L 9945% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Santa Barbara Water Department | Santa Barbara | CA | 994500 µg/L 9945% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Liberty -Yermo | — | CA | 994000 µg/L 9940% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Redlands City Mud-Water Div | Redlands | CA | 993000 µg/L 9930% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Liberty Utilities - Bellflower-Norwalk | Downey | CA | 989500 µg/L 9895% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Alpine Water Users Association | Twin Peaks | CA | 987500 µg/L 9875% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Benicia | Benicia | CA | 985650 µg/L 9857% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| American Canyon, City of | American Canyon | CA | 985650 µg/L 9857% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Vallejo | Vallejo | CA | 985650 µg/L 9857% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Travis Afb Wtp - Vallejo | Vallejo | CA | 985650 µg/L 9857% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Palm Springs Crest | Desert Hot Springs | CA | 982000 µg/L 9820% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| O'Connor Tract Co-Operative Water Co. | — | CA | 979000 µg/L 9790% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Los Angeles Residential Community Founda | Santa Clarita | CA | 975000 µg/L 9750% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Coachella Vwd: Cove Community | Palm Desert | CA | 973000 µg/L 9730% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| City of Red Bluff | Red Bluff | CA | 970000 µg/L 9700% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Stockton East Water District | Stockton | CA | 960000 µg/L 9600% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
| Montecito Sea Meadows | Santa Barbara | CA | 960000 µg/L 9600% of the EPA limit, at the 95th percentile of samples — 10000 µg/L |
Frequently asked questions about Nitrate-Nitrite
What is Nitrate-Nitrite in drinking water?
Nitrate-nitrite is the combined measure of both nitrogen forms, mainly from fertiliser and sewage.
What is the EPA limit for Nitrate-Nitrite?
The EPA's Maximum Contaminant Level for Nitrate-Nitrite is 10000 µg/L, and its health goal (MCLG) is 10000 µg/L. A result above the limit means the supplier must act; the goal is the level at which no health effects are expected.
How common is Nitrate-Nitrite in US tap water?
Of the 24,125 water suppliers with results on file, 18,509 detected Nitrate-Nitrite — 76.7% of those tested.