Nitrate
Mountain Regional Water Special Service District
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 | 0.315 ppm | 16 | 11 | ND - 0.773 ppm |
| 2019 | 0.483 ppm | 14 | 13 | ND - 0.953 ppm |
| 2020 | 0.512 ppm | 18 | 16 | ND - 1.10 ppm |
| 2021 | 0.412 ppm | 22 | 20 | ND - 1.07 ppm |
| 2022 | 0.352 ppm | 20 | 15 | ND - 1.20 ppm |
| 2023 | 1.01 ppm | 17 | 14 | ND - 7.41 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 |
|---|---|
| 2018-03-20 | 0.756 ppm |
| 2018-03-20 | 0.687 ppm |
| 2018-03-20 | 0.773 ppm |
| 2018-03-20 | 0.760 ppm |
| 2018-06-06 | 0.430 ppm |
| 2018-06-20 | 0.255 ppm |
| 2018-06-20 | 0.227 ppm |
| 2018-08-23 | ND |
| 2018-09-05 | ND |
| 2018-09-05 | ND |
| 2018-09-05 | 0.187 ppm |
| 2018-09-05 | 0.530 ppm |
| 2018-09-05 | ND |
| 2018-09-05 | 0.302 ppm |
| 2018-09-05 | 0.142 ppm |
| 2018-09-05 | ND |
| 2019-01-03 | 0.438 ppm |
| 2019-01-03 | 0.691 ppm |
| 2019-01-03 | 0.953 ppm |
| 2019-01-03 | 0.295 ppm |
| 2019-01-24 | 0.757 ppm |
| 2019-01-24 | 0.774 ppm |
| 2019-01-24 | 0.179 ppm |
| 2019-02-25 | 0.591 ppm |
| 2019-02-25 | 0.457 ppm |
| 2019-02-25 | 0.229 ppm |
| 2019-02-25 | 0.139 ppm |
| 2019-03-20 | 0.763 ppm |
| 2019-11-07 | 0.494 ppm |
| 2019-11-14 | ND |
| 2020-02-27 | 1.000 ppm |
| 2020-03-24 | 0.454 ppm |
| 2020-07-13 | ND |
| 2020-07-14 | 1.03 ppm |
| 2020-09-15 | ND |
| 2020-09-15 | 0.900 ppm |
| 2020-09-15 | 1.10 ppm |
| 2020-09-15 | 0.700 ppm |
| 2020-09-15 | 0.500 ppm |
| 2020-09-15 | 0.400 ppm |
| 2020-09-15 | 0.200 ppm |
| 2020-09-15 | 0.300 ppm |
| 2020-09-15 | 0.400 ppm |
| 2020-09-16 | 0.400 ppm |
| 2020-09-16 | 0.800 ppm |
| 2020-09-16 | 0.200 ppm |
| 2020-09-16 | 0.700 ppm |
| 2020-09-21 | 0.126 ppm |
| 2021-03-16 | 0.800 ppm |
| 2021-03-16 | 0.431 ppm |
| 2021-06-03 | 0.467 ppm |
| 2021-06-03 | 0.815 ppm |
| 2021-06-03 | 0.113 ppm |
| 2021-06-03 | 0.205 ppm |
| 2021-06-03 | 0.301 ppm |
| 2021-06-03 | 0.675 ppm |
| 2021-06-08 | ND |
| 2021-08-04 | 0.364 ppm |
| 2021-09-07 | 0.750 ppm |
| 2021-09-07 | 0.192 ppm |
| 2021-09-07 | 0.200 ppm |
| 2021-09-08 | ND |
| 2021-09-08 | 1.07 ppm |
| 2021-09-08 | 0.709 ppm |
| 2021-09-08 | 0.705 ppm |
| 2021-09-08 | 0.124 ppm |
| 2021-09-08 | 0.171 ppm |
| 2021-09-08 | 0.300 ppm |
| 2021-12-08 | 0.260 ppm |
| 2021-12-08 | 0.403 ppm |
| 2022-02-17 | ND |
| 2022-02-17 | ND |
| 2022-02-17 | ND |
| 2022-02-17 | 1.03 ppm |
| 2022-02-17 | 0.519 ppm |
| 2022-05-04 | 0.181 ppm |
| 2022-05-05 | 0.796 ppm |
| 2022-05-05 | 0.173 ppm |
| 2022-05-05 | 0.844 ppm |
| 2022-08-04 | 0.500 ppm |
| 2022-08-04 | 0.331 ppm |
| 2022-08-04 | 0.200 ppm |
| 2022-08-04 | 0.200 ppm |
| 2022-08-04 | 0.200 ppm |
| 2022-08-04 | ND |
| 2022-09-07 | 0.187 ppm |
| 2022-09-22 | ND |
| 2022-12-06 | 0.104 ppm |
| 2022-12-06 | 1.20 ppm |
| 2022-12-07 | 0.587 ppm |
| 2023-09-07 | 0.130 ppm |
| 2023-11-06 | 1.23 ppm |
| 2023-11-06 | 1.41 ppm |
| 2023-11-06 | 7.41 ppm |
| 2023-11-06 | 1.60 ppm |
| 2023-11-06 | 0.238 ppm |
| 2023-11-06 | 0.233 ppm |
| 2023-12-11 | 0.409 ppm |
| 2023-12-11 | ND |
| 2023-12-11 | 1.03 ppm |
| 2023-12-11 | 0.983 ppm |
| 2023-12-11 | 0.849 ppm |
| 2023-12-11 | 0.481 ppm |
| 2023-12-11 | ND |
| 2023-12-11 | 0.986 ppm |
| 2023-12-11 | ND |
| 2023-12-11 | 0.220 ppm |