Nitrate
Westbound Water Supply Corporation Cisco Source
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 | 0.686 ppm | 4 | 4 | 0.145 ppm - 1.36 ppm |
| 2019 | 0.678 ppm | 4 | 4 | 0.0919 ppm - 1.40 ppm |
| 2020 | 0.580 ppm | 4 | 4 | 0.0892 ppm - 1.42 ppm |
| 2021 | 0.717 ppm | 4 | 4 | 0.107 ppm - 1.45 ppm |
| 2022 | 0.494 ppm | 4 | 4 | 0.137 ppm - 1.42 ppm |
| 2023 | 0.566 ppm | 4 | 4 | 0.0161 ppm - 1.41 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 |
|---|---|---|
| 2018-11-28 | Q1848312006 | 1.36 ppm |
| 2018-11-28 | Q1848312007 | 0.305 ppm |
| 2018-11-28 | Q1848312008 | 0.932 ppm |
| 2018-11-28 | Q1848312005 | 0.145 ppm |
| 2019-12-17 | Q1980357001 | 1.40 ppm |
| 2019-12-17 | Q1980357002 | 0.172 ppm |
| 2019-12-17 | Q1980357003 | 1.05 ppm |
| 2019-12-17 | Q1980357009 | 0.0919 ppm |
| 2020-06-04 | Q2022359007 | 0.674 ppm |
| 2020-11-09 | Q2043631012 | 1.42 ppm |
| 2020-11-09 | Q2043631015 | 0.0892 ppm |
| 2020-11-09 | Q2043631016 | 0.136 ppm |
| 2021-02-09 | Q2103863005 | 0.107 ppm |
| 2021-02-09 | Q2103863008 | 1.05 ppm |
| 2021-02-09 | Q2103863007 | 0.262 ppm |
| 2021-02-09 | Q2103863006 | 1.45 ppm |
| 2022-02-16 | Q2205765006 | 0.137 ppm |
| 2022-02-16 | Q2205765007 | 1.42 ppm |
| 2022-02-16 | Q2205765008 | 0.280 ppm |
| 2022-02-16 | Q2205765009 | 0.140 ppm |
| 2023-02-07 | Q2304671001 | 0.683 ppm |
| 2023-07-12 | Q2327347007 | 1.41 ppm |
| 2023-07-12 | Q2327347010 | 0.0161 ppm |
| 2023-07-12 | Q2327347011 | 0.153 ppm |