Nitrate
Danbury Water Department
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.349 ppm | 4 | 4 | 0.0870 ppm - 0.640 ppm |
| 2019 | 0.120 ppm | 6 | 6 | 0.0300 ppm - 0.230 ppm |
| 2020 | 0.281 ppm | 2 | 2 | 0.235 ppm - 0.327 ppm |
| 2021 | ND | 4 | 0 | ND |
| 2022 | 0.125 ppm | 4 | 2 | ND - 0.300 ppm |
| 2023 | 0.0333 ppm | 6 | 1 | ND - 0.200 ppm |
ppm = parts per million
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 0.14 ppm
The EWG health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.
EPA Maximum Contaminant
Level (MCL): 10 ppm
The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-04-12 | 212690GE | 0.580 ppm |
| 2018-04-12 | 212687GE | 0.640 ppm |
| 2018-07-12 | NOX 200499427 | 0.0870 ppm |
| 2018-07-12 | NOX 200499426 | 0.0870 ppm |
| 2019-04-11 | NOX 200528182 | 0.0490 ppm |
| 2019-04-11 | NOX 200528181 | 0.181 ppm |
| 2019-04-11 | NOX 200528185 | 0.173 ppm |
| 2019-04-11 | NOX 200528187 | 0.0300 ppm |
| 2019-11-21 | NOX 200557773 | 0.0590 ppm |
| 2019-11-21 | NOX 200557768 | 0.230 ppm |
| 2020-02-20 | NOX 200566893 | 0.327 ppm |
| 2020-02-20 | NOX 200566892 | 0.235 ppm |
| 2021-07-20 | 269417 | ND |
| 2021-07-20 | 269416 | ND |
| 2021-12-16 | 278015 | ND |
| 2021-12-16 | 278014 | ND |
| 2022-06-07 | 287323 | 0.300 ppm |
| 2022-06-07 | 287327 | 0.200 ppm |
| 2022-12-15 | 303055 | ND |
| 2022-12-15 | 303056 | ND |
| 2023-01-12 | 304532 | ND |
| 2023-01-12 | 304533 | ND |
| 2023-05-15 | N3E0590-02PPS | ND |
| 2023-05-15 | N3E0590-01PPS | ND |
| 2023-11-09 | CP44983 | ND |
| 2023-11-09 | CP44982 | 0.200 ppm |