Nitrate and nitrite
Cws-split Mountain Water System
Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. 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 | 1.30 ppm | 2 | 2 | 1.30 ppm |
| 2019 | 0.577 ppm | 3 | 3 | 0.410 ppm - 0.680 ppm |
| 2020 | 0.730 ppm | 3 | 3 | 0.450 ppm - 0.880 ppm |
| 2021 | 0.457 ppm | 3 | 3 | 0.450 ppm - 0.460 ppm |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | 0.853 ppm | 3 | 3 | 0.760 ppm - 1.000 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
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-01-23 | CA1500407_006_006-201801230950 | 1.30 ppm |
| 2018-01-23 | CA1500407_005_005-201801231010 | 1.30 ppm |
| 2019-01-15 | CA1500407_006_006-201901151132 | 0.640 ppm |
| 2019-01-15 | CA1500407_005_005-201901151150 | 0.680 ppm |
| 2019-05-13 | CA1500407_002_002-201905130958 | 0.410 ppm |
| 2020-01-22 | CA1500407_005_005-202001221450 | 0.860 ppm |
| 2020-01-22 | CA1500407_006_006-202001221438 | 0.880 ppm |
| 2020-02-11 | CA1500407_007_007-202002111247 | 0.450 ppm |
| 2021-01-26 | CA1500407_006_006-202101261336 | 0.460 ppm |
| 2021-01-26 | CA1500407_006_006-202101261336 | 0.460 ppm |
| 2021-01-26 | CA1500407_005_005-202101261344 | 0.450 ppm |
| 2023-01-26 | CA1500407_005_005-202301260926 | 0.800 ppm |
| 2023-01-26 | CA1500407_006_006-202301260934 | 0.760 ppm |
| 2023-02-23 | CA1500407_007_007-202302231300 | 1.000 ppm |