Nitrate
West Harris County Municipal Utility District 15
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 | 0.350 ppm | 2 | 2 | 0.300 ppm - 0.400 ppm |
| 2019 | 0.753 ppm | 2 | 2 | 0.590 ppm - 0.916 ppm |
| 2020 | 0.400 ppm | 2 | 2 | 0.320 ppm - 0.480 ppm |
| 2021 | 0.235 ppm | 2 | 2 | 0.110 ppm - 0.360 ppm |
| 2022 | 0.265 ppm | 2 | 2 | 0.250 ppm - 0.280 ppm |
| 2023 | 0.650 ppm | 4 | 4 | 0.0600 ppm - 1.22 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 |
|---|---|---|
| 2018-03-05 | AE16545 | 0.300 ppm |
| 2018-03-05 | AE16546 | 0.400 ppm |
| 2019-01-28 | AE51464 | 0.590 ppm |
| 2019-04-23 | Q1916434001 | 0.916 ppm |
| 2020-01-13 | AE93016 | 0.480 ppm |
| 2020-11-05 | AF33382 | 0.320 ppm |
| 2021-03-09 | AF45882 | 0.110 ppm |
| 2021-04-27 | AF51361 | 0.360 ppm |
| 2022-03-01 | AF86755 | 0.250 ppm |
| 2022-03-01 | AF86756 | 0.280 ppm |
| 2023-02-22 | AG29834 | 0.640 ppm |
| 2023-02-22 | AG29843 | 0.680 ppm |
| 2023-07-17 | AG48620 | 0.0600 ppm |
| 2023-10-09 | AG58758 | 1.22 ppm |