Nitrate
Westchester County Water District #3
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 | 0.161 ppm | 1 | 1 | 0.161 ppm |
| 2019 | 0.129 ppm | 1 | 1 | 0.129 ppm |
| 2020 | 0.302 ppm | 4 | 4 | 0.0970 ppm - 0.880 ppm |
| 2021 | 0.162 ppm | 4 | 4 | 0.143 ppm - 0.208 ppm |
| 2022 | 0.161 ppm | 4 | 4 | 0.101 ppm - 0.262 ppm |
| 2023 | 0.0952 ppm | 4 | 4 | 0.0668 ppm - 0.135 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 |
|---|---|---|
| 2018-10-02 | AU213276NIT | 0.161 ppm |
| 2019-11-21 | AV24564NIT | 0.129 ppm |
| 2020-04-28 | AW07856NIT | 0.124 ppm |
| 2020-11-17 | AW22089NIT | 0.880 ppm |
| 2020-12-15 | AW23891-NIT | 0.105 ppm |
| 2020-12-15 | AW23893-NIT | 0.0970 ppm |
| 2021-04-06 | AX06359-NIT | 0.208 ppm |
| 2021-10-29 | AX21799-NIT | 0.143 ppm |
| 2021-11-09 | AX22573-NIT | 0.150 ppm |
| 2021-11-09 | AX22576-NIT | 0.145 ppm |
| 2022-04-11 | AY05984-NIT | 0.123 ppm |
| 2022-10-19 | AY18880-NIT | 0.101 ppm |
| 2022-11-01 | AY19681-NIT | 0.262 ppm |
| 2022-11-01 | AY19679-NIT | 0.156 ppm |
| 2023-04-25 | AZ07359-NIT | 0.135 ppm |
| 2023-10-19 | AZ19381-NIT | 0.101 ppm |
| 2023-11-01 | AZ20240-NIT | 0.0668 ppm |
| 2023-11-01 | AZ20238-NIT | 0.0778 ppm |