Nitrate
Costilla County Ws
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 | 0.280 ppm | 3 | 2 | ND - 0.510 ppm |
| 2019 | 0.413 ppm | 3 | 3 | 0.240 ppm - 0.600 ppm |
| 2020 | 0.500 ppm | 3 | 3 | 0.230 ppm - 0.680 ppm |
| 2021 | 0.357 ppm | 3 | 3 | 0.200 ppm - 0.460 ppm |
| 2022 | 0.680 ppm | 3 | 3 | 0.520 ppm - 0.890 ppm |
| 2023 | 0.577 ppm | 3 | 3 | 0.280 ppm - 0.760 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 | Result |
|---|---|
| 2018-10-16 | 0.510 ppm |
| 2018-10-16 | ND |
| 2018-10-16 | 0.330 ppm |
| 2019-08-23 | 0.400 ppm |
| 2019-08-23 | 0.240 ppm |
| 2019-08-23 | 0.600 ppm |
| 2020-12-16 | 0.680 ppm |
| 2020-12-16 | 0.230 ppm |
| 2020-12-21 | 0.590 ppm |
| 2021-11-30 | 0.410 ppm |
| 2021-11-30 | 0.200 ppm |
| 2021-11-30 | 0.460 ppm |
| 2022-10-24 | 0.890 ppm |
| 2022-10-24 | 0.630 ppm |
| 2022-10-24 | 0.520 ppm |
| 2023-03-21 | 0.760 ppm |
| 2023-03-27 | 0.690 ppm |
| 2023-03-27 | 0.280 ppm |