Nitrate and nitrite
Eureka
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.
31
Samples
0
Samples exceeding legal limit (MCL)
20
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.456 ppm | 4 | 3 | ND - 0.900 ppm |
| 2015 | 0.481 ppm | 5 | 5 | 0.0320 ppm - 0.840 ppm |
| 2016 | 0.396 ppm | 5 | 5 | 0.0270 ppm - 0.700 ppm |
| 2017 | 0.403 ppm | 5 | 5 | 0.0270 ppm - 0.670 ppm |
| 2018 | 0.463 ppm | 6 | 6 | 0.0560 ppm - 0.700 ppm |
| 2019 | 0.558 ppm | 6 | 6 | 0.0900 ppm - 0.760 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EWG Health Guideline 0.14 ppm
The 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 |
|---|---|---|
| 2014-01-27 | AC17086 | 0.0320 ppm |
| 2014-01-27 | AC17087 | 0.900 ppm |
| 2014-01-27 | AC17088 | ND |
| 2014-01-27 | AC17085 | 0.890 ppm |
| 2015-09-03 | AC57872 | 0.0320 ppm |
| 2015-09-03 | AC57869 | 0.700 ppm |
| 2015-09-03 | AC57871 | 0.840 ppm |
| 2015-09-03 | AC57870 | 0.0350 ppm |
| 2015-09-29 | AC59848 | 0.800 ppm |
| 2016-08-16 | AC82082 | 0.560 ppm |
| 2016-08-16 | AC82081 | 0.650 ppm |
| 2016-08-16 | AC82083 | 0.0440 ppm |
| 2016-08-16 | AC82080 | 0.700 ppm |
| 2016-08-16 | AC82079 | 0.0270 ppm |
| 2017-08-15 | AD03715 | 0.670 ppm |
| 2017-08-15 | AD03712 | 0.0470 ppm |
| 2017-08-15 | AD03714 | 0.0270 ppm |
| 2017-08-15 | AD03713 | 0.620 ppm |
| 2017-08-15 | AD03711 | 0.650 ppm |
| 2018-08-17 | AD30837 | 0.660 ppm |
| 2018-08-17 | AD30838 | 0.690 ppm |
| 2018-08-17 | AD30839 | 0.700 ppm |
| 2018-08-17 | AD30840 | 0.0640 ppm |
| 2018-08-17 | AD30841 | 0.0560 ppm |
| 2018-09-14 | AD33873 | 0.610 ppm |
| 2019-08-26 | AD53651 | 0.420 ppm |
| 2019-08-26 | AD53652 | 0.760 ppm |
| 2019-08-26 | AD53653 | 0.650 ppm |
| 2019-08-26 | AD53654 | 0.690 ppm |
| 2019-08-26 | AD53655 | 0.740 ppm |
| 2019-08-26 | AD53656 | 0.0900 ppm |