Nitrate
Harris County MUD 422
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 | 0.590 ppm | 3 | 3 | 0.0800 ppm - 0.950 ppm |
| 2019 | 0.608 ppm | 4 | 4 | 0.0700 ppm - 1.15 ppm |
| 2020 | 0.420 ppm | 4 | 4 | 0.0600 ppm - 1.14 ppm |
| 2021 | 0.408 ppm | 4 | 4 | 0.0900 ppm - 0.730 ppm |
| 2022 | 0.365 ppm | 4 | 4 | 0.0800 ppm - 0.950 ppm |
| 2023 | 0.518 ppm | 4 | 4 | 0.0800 ppm - 0.980 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 |
|---|---|---|
| 2018-06-08 | AE29116 | 0.0800 ppm |
| 2018-08-30 | AE38849 | 0.740 ppm |
| 2018-12-04 | AE47681 | 0.950 ppm |
| 2019-03-14 | AE58338 | 1.15 ppm |
| 2019-06-03 | AE68780 | 0.390 ppm |
| 2019-09-06 | AE82403 | 0.0700 ppm |
| 2019-11-07 | AE88815 | 0.820 ppm |
| 2020-02-13 | AE98280 | 1.14 ppm |
| 2020-04-29 | AF08600 | 0.390 ppm |
| 2020-07-27 | AF20560 | 0.0900 ppm |
| 2020-11-09 | AF33636 | 0.0600 ppm |
| 2021-02-01 | AF41755 | 0.730 ppm |
| 2021-06-10 | AF57315 | 0.360 ppm |
| 2021-08-11 | AF65795 | 0.0900 ppm |
| 2021-11-01 | AF75162 | 0.450 ppm |
| 2022-02-07 | AF83051 | 0.950 ppm |
| 2022-04-25 | AF94131 | 0.310 ppm |
| 2022-08-23 | AG10399 | 0.0800 ppm |
| 2022-11-21 | AG19307 | 0.120 ppm |
| 2023-01-25 | AG26357 | 0.980 ppm |
| 2023-04-17 | AG36827 | 0.270 ppm |
| 2023-07-25 | AG49918 | 0.0800 ppm |
| 2023-11-30 | AG64930 | 0.740 ppm |