Nitrate and nitrite
Aquarion Water Company of Connecticut - Stamford
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 | 0.00900 ppm | 2 | 2 | 0.00500 ppm - 0.0130 ppm |
| 2019 | 0.213 ppm | 2 | 2 | 0.206 ppm - 0.220 ppm |
| 2020 | 0.0875 ppm | 4 | 4 | 0.0430 ppm - 0.133 ppm |
| 2021 | 0.185 ppm | 2 | 2 | 0.184 ppm - 0.185 ppm |
| 2022 | 0.0210 ppm | 5 | 1 | ND - 0.105 ppm |
| 2023 | 0.0335 ppm | 4 | 2 | ND - 0.119 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 |
|---|---|---|
| 2018-01-02 | 201800021-NOX | 0.0130 ppm |
| 2018-01-02 | 201800018-IOCR | 0.00500 ppm |
| 2019-01-07 | 201900231-IOCR | 0.206 ppm |
| 2019-01-07 | 201900234-NOX | 0.220 ppm |
| 2020-01-06 | 202000151-IOCR | 0.133 ppm |
| 2020-01-06 | 202000154-NOX | 0.127 ppm |
| 2020-07-06 | 202010216-IOCR | 0.0470 ppm |
| 2020-07-06 | 202010220-NOX | 0.0430 ppm |
| 2021-01-04 | 202100057-NOX | 0.184 ppm |
| 2021-01-04 | 202100054-IOCR | 0.185 ppm |
| 2022-01-03 | 202200070-IOCR | ND |
| 2022-01-03 | 202200073-NOX | 0.105 ppm |
| 2022-07-18 | 202212143-IOCR | ND |
| 2022-07-18 | 202212143-NOX | ND |
| 2022-07-18 | 202212142-NOX | ND |
| 2023-01-03 | 202300186-IOCR | ND |
| 2023-01-03 | 202300189-NOX | 0.119 ppm |
| 2023-08-07 | 202313852-IOCR | ND |
| 2023-08-07 | 202313851-NOX | 0.0150 ppm |