Nitrate
Harris County Municipal Utility District 372
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 | 0.500 ppm | 1 | 1 | 0.500 ppm |
| 2019 | 0.300 ppm | 1 | 1 | 0.300 ppm |
| 2020 | 0.280 ppm | 4 | 4 | 0.150 ppm - 0.450 ppm |
| 2021 | 0.175 ppm | 4 | 4 | 0.0700 ppm - 0.310 ppm |
| 2022 | 0.127 ppm | 3 | 3 | 0.110 ppm - 0.150 ppm |
| 2023 | 0.0925 ppm | 4 | 4 | 0.0800 ppm - 0.1000 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 |
|---|---|---|
| 2018-01-11 | AE08794 | 0.500 ppm |
| 2019-04-04 | AE61134 | 0.300 ppm |
| 2020-03-02 | AF00530 | 0.450 ppm |
| 2020-06-09 | AF14598 | 0.220 ppm |
| 2020-07-23 | AF20349 | 0.300 ppm |
| 2020-11-20 | AF35393 | 0.150 ppm |
| 2021-03-05 | AF45572 | 0.240 ppm |
| 2021-04-13 | AF49867 | 0.310 ppm |
| 2021-08-30 | AF68324 | 0.0800 ppm |
| 2021-10-25 | AF74416 | 0.0700 ppm |
| 2022-02-14 | AF84450 | 0.110 ppm |
| 2022-05-18 | AF97635 | 0.120 ppm |
| 2022-12-12 | AG21386 | 0.150 ppm |
| 2023-02-15 | AG28980 | 0.0900 ppm |
| 2023-04-19 | AG37247 | 0.1000 ppm |
| 2023-08-01 | AG50662 | 0.1000 ppm |
| 2023-10-30 | AG61414 | 0.0800 ppm |