Nitrate and nitrite
Bristol 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 | 0.651 ppm | 5 | 5 | 0.0972 ppm - 1.85 ppm |
| 2019 | 0.861 ppm | 5 | 5 | 0.111 ppm - 2.42 ppm |
| 2020 | 0.584 ppm | 5 | 5 | 0.135 ppm - 1.33 ppm |
| 2021 | 0.582 ppm | 5 | 4 | ND - 1.40 ppm |
| 2022 | 0.591 ppm | 5 | 5 | 0.0599 ppm - 1.38 ppm |
| 2023 | 0.109 ppm | 1 | 1 | 0.109 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 |
|---|---|---|
| 2018-01-10 | D8A0565-04NOX | 0.107 ppm |
| 2018-01-10 | D8A0565-03NOX | 1.09 ppm |
| 2018-01-10 | D8A0565-02NOX | 1.85 ppm |
| 2018-01-10 | D8A0565-01NOX | 0.0972 ppm |
| 2018-03-07 | D8C0471-01NOXR | 0.117 ppm |
| 2019-03-27 | D9C2628-01NOX | 0.111 ppm |
| 2019-03-27 | D9C2628-04NOX | 0.117 ppm |
| 2019-03-27 | D9C2628-03NOX | 1.54 ppm |
| 2019-03-27 | D9C2628-02NOX | 2.42 ppm |
| 2019-03-27 | D9C2626-01IOCR | 0.118 ppm |
| 2020-01-31 | D0A2597-04NOX | 1.18 ppm |
| 2020-01-31 | D0A2598-01IOCR | 0.139 ppm |
| 2020-01-31 | D0A2597-03NOX | 1.33 ppm |
| 2020-01-31 | D0A2597-02NOX | 0.137 ppm |
| 2020-01-31 | D0A2597-01NOX | 0.135 ppm |
| 2021-02-25 | D1B2168-01NOX | 0.0706 ppm |
| 2021-02-25 | D1B2168-02NOX | 0.0860 ppm |
| 2021-02-25 | D1B2168-03NOX | 1.35 ppm |
| 2021-02-25 | D1B2168-04NOX | 1.40 ppm |
| 2021-12-16 | 21121612-003-IOC | ND |
| 2022-02-03 | D2B0373-01IOC | 0.0599 ppm |
| 2022-04-07 | D2D0784-01NOX | 0.101 ppm |
| 2022-04-07 | D2D0784-02NOX | 0.102 ppm |
| 2022-04-07 | D2D0784-03NOX | 1.38 ppm |
| 2022-04-07 | D2D0887-01NOX | 1.32 ppm |
| 2023-02-23 | D3B2331-01IOC | 0.109 ppm |