Nitrate
Collierville 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 | 0.454 ppm | 4 | 4 | 0.249 ppm - 0.677 ppm |
| 2019 | 0.466 ppm | 4 | 4 | 0.230 ppm - 0.692 ppm |
| 2020 | 0.374 ppm | 4 | 4 | 0.228 ppm - 0.594 ppm |
| 2021 | 0.528 ppm | 4 | 4 | 0.296 ppm - 0.754 ppm |
| 2022 | 0.606 ppm | 8 | 8 | 0.460 ppm - 0.794 ppm |
| 2023 | 0.510 ppm | 4 | 4 | 0.275 ppm - 0.712 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 | Result |
|---|---|
| 2018-05-15 | 0.249 ppm |
| 2018-05-15 | 0.677 ppm |
| 2018-05-15 | 0.430 ppm |
| 2018-05-15 | 0.460 ppm |
| 2019-03-11 | 0.513 ppm |
| 2019-03-11 | 0.230 ppm |
| 2019-03-11 | 0.692 ppm |
| 2019-03-11 | 0.428 ppm |
| 2020-03-05 | 0.281 ppm |
| 2020-03-05 | 0.594 ppm |
| 2020-03-05 | 0.228 ppm |
| 2020-03-05 | 0.394 ppm |
| 2021-03-18 | 0.473 ppm |
| 2021-03-18 | 0.754 ppm |
| 2021-03-18 | 0.296 ppm |
| 2021-03-18 | 0.587 ppm |
| 2022-03-08 | 0.660 ppm |
| 2022-03-08 | 0.460 ppm |
| 2022-03-08 | 0.794 ppm |
| 2022-03-08 | 0.510 ppm |
| 2022-03-08 | 0.660 ppm |
| 2022-03-08 | 0.460 ppm |
| 2022-03-08 | 0.794 ppm |
| 2022-03-08 | 0.510 ppm |
| 2023-03-15 | 0.531 ppm |
| 2023-03-15 | 0.275 ppm |
| 2023-03-15 | 0.712 ppm |
| 2023-03-15 | 0.522 ppm |