Nitrate
Harris County MUD 400 - East
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 | 0.154 ppm | 44 | 34 | ND - 0.780 ppm |
| 2019 | 0.485 ppm | 2 | 2 | 0.200 ppm - 0.770 ppm |
| 2020 | 0.435 ppm | 4 | 4 | 0.0800 ppm - 1.17 ppm |
| 2021 | 0.410 ppm | 4 | 4 | 0.0900 ppm - 0.700 ppm |
| 2022 | 0.363 ppm | 4 | 4 | 0.0900 ppm - 0.890 ppm |
| 2023 | 0.298 ppm | 4 | 4 | 0.0700 ppm - 0.640 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 |
|---|---|---|
| 2019-09-25 | AE84505 | 0.200 ppm |
| 2019-11-07 | AE88812 | 0.770 ppm |
| 2020-02-13 | AE98287 | 1.17 ppm |
| 2020-04-29 | AF08601 | 0.390 ppm |
| 2020-09-03 | AF26354 | 0.1000 ppm |
| 2020-11-09 | AF33653 | 0.0800 ppm |
| 2021-02-01 | AF41753 | 0.700 ppm |
| 2021-06-10 | AF57317 | 0.370 ppm |
| 2021-08-11 | AF65792 | 0.0900 ppm |
| 2021-11-01 | AF75163 | 0.480 ppm |
| 2022-02-07 | AF83048 | 0.890 ppm |
| 2022-04-25 | AF94134 | 0.320 ppm |
| 2022-08-23 | AG10398 | 0.0900 ppm |
| 2022-11-21 | AG19286 | 0.150 ppm |
| 2023-03-23 | AG34032 | 0.640 ppm |
| 2023-04-17 | AG36829 | 0.300 ppm |
| 2023-07-25 | AG49917 | 0.0700 ppm |
| 2023-10-30 | AG61408 | 0.180 ppm |