Nitrate
Harris County Municipal Utility District 196
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 | 0.671 ppm | 9 | 9 | 0.200 ppm - 1.02 ppm |
| 2019 | 0.607 ppm | 3 | 3 | 0.510 ppm - 0.740 ppm |
| 2020 | 0.800 ppm | 3 | 3 | 0.620 ppm - 1.13 ppm |
| 2021 | 0.365 ppm | 2 | 2 | 0.150 ppm - 0.580 ppm |
| 2022 | 0.285 ppm | 2 | 2 | 0.280 ppm - 0.290 ppm |
| 2023 | 0.655 ppm | 2 | 2 | 0.650 ppm - 0.660 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 |
|---|---|---|
| 2018-02-22 | AE14926 | 0.620 ppm |
| 2018-02-22 | AE14920 | 0.920 ppm |
| 2018-04-17 | AE22656 | 0.930 ppm |
| 2018-04-17 | AE22672 | 0.550 ppm |
| 2018-04-17 | AE22675 | 0.870 ppm |
| 2018-09-13 | AE39905 | 0.200 ppm |
| 2018-09-13 | AE39906 | 0.370 ppm |
| 2018-12-13 | AE48755 | 0.560 ppm |
| 2018-12-13 | AE48756 | 1.02 ppm |
| 2019-02-19 | AE54777 | 0.510 ppm |
| 2019-02-19 | AE54778 | 0.570 ppm |
| 2019-02-19 | AE54775 | 0.740 ppm |
| 2020-02-06 | AE97199 | 1.13 ppm |
| 2020-04-29 | AF08592 | 0.650 ppm |
| 2020-04-29 | AF08593 | 0.620 ppm |
| 2021-02-05 | AF42873 | 0.580 ppm |
| 2021-07-19 | AF62284 | 0.150 ppm |
| 2022-03-15 | AF89008 | 0.290 ppm |
| 2022-03-15 | AF89011 | 0.280 ppm |
| 2023-02-23 | AG30123 | 0.660 ppm |
| 2023-02-23 | AG30124 | 0.650 ppm |