Nitrate and nitrite
Danbury Water Department
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. 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 | 0.198 ppm | 4 | 4 | 0.0220 ppm - 0.327 ppm |
| 2021 | 0.0650 ppm | 6 | 4 | ND - 0.185 ppm |
| 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
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 |
| 2020-08-20 | IOCR 200587327 | 0.0220 ppm |
| 2020-08-20 | IOCR 200587329 | 0.206 ppm |
| 2021-04-15 | IOCR 200613296 | 0.115 ppm |
| 2021-04-15 | IOCR 200613294 | 0.185 ppm |
| 2021-07-20 | 269416 | 0.0400 ppm |
| 2021-07-20 | 269417 | 0.0500 ppm |
| 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 |