Nitrate
South Grayson Special Utility District
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 | 0.120 ppm | 5 | 5 | 0.0427 ppm - 0.371 ppm |
| 2019 | 0.156 ppm | 5 | 5 | 0.0526 ppm - 0.401 ppm |
| 2020 | 0.0893 ppm | 5 | 5 | 0.0392 ppm - 0.257 ppm |
| 2021 | 0.0562 ppm | 5 | 5 | 0.0438 ppm - 0.0607 ppm |
| 2022 | 0.0670 ppm | 5 | 5 | 0.0474 ppm - 0.120 ppm |
| 2023 | 0.490 ppm | 5 | 5 | 0.0552 ppm - 1.94 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 |
|---|---|---|
| 2018-02-06 | Q1804974008 | 0.0450 ppm |
| 2018-10-15 | Q1840862004 | 0.0467 ppm |
| 2018-10-15 | Q1840862005 | 0.0970 ppm |
| 2018-10-15 | Q1840862016 | 0.0427 ppm |
| 2018-10-15 | Q1840862017 | 0.371 ppm |
| 2019-08-13 | Q1954236003 | 0.0526 ppm |
| 2019-08-13 | Q1954236004 | 0.401 ppm |
| 2019-08-13 | Q1954236005 | 0.211 ppm |
| 2019-08-13 | Q1954236006 | 0.0623 ppm |
| 2019-08-13 | Q1954236009 | 0.0528 ppm |
| 2020-08-06 | Q2031194020 | 0.0392 ppm |
| 2020-08-06 | Q2031194021 | 0.257 ppm |
| 2020-08-06 | Q2031194022 | 0.0450 ppm |
| 2020-08-06 | Q2031194023 | 0.0517 ppm |
| 2020-08-06 | Q2031194037 | 0.0537 ppm |
| 2021-06-16 | Q2115771006 | 0.0601 ppm |
| 2021-11-10 | Q2131631006 | 0.0593 ppm |
| 2021-11-10 | Q2131631007 | 0.0438 ppm |
| 2021-11-10 | Q2131631008 | 0.0607 ppm |
| 2021-11-10 | Q2131631009 | 0.0572 ppm |
| 2022-02-08 | Q2204251004 | 0.120 ppm |
| 2022-04-26 | Q2212466003 | 0.0474 ppm |
| 2022-04-26 | Q2212466004 | 0.0629 ppm |
| 2022-04-26 | Q2212466005 | 0.0497 ppm |
| 2022-04-26 | Q2212466006 | 0.0551 ppm |
| 2023-05-16 | Q2318439018 | 0.0570 ppm |
| 2023-05-16 | Q2318439019 | 0.0617 ppm |
| 2023-05-16 | Q2318439020 | 0.334 ppm |
| 2023-05-16 | Q2318439021 | 0.0552 ppm |
| 2023-05-16 | Q2318439037 | 1.94 ppm |