Nitrate and nitrite
City of Sherwood
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 0.376 ppm | 5 | 5 | 0.250 ppm - 0.540 ppm |
2015 | 0.435 ppm | 4 | 4 | 0.290 ppm - 0.630 ppm |
2016 | 0.664 ppm | 5 | 5 | 0.320 ppm - 1.10 ppm |
2017 | 0.445 ppm | 4 | 4 | 0.190 ppm - 0.710 ppm |
2018 | 0.508 ppm | 4 | 4 | 0.270 ppm - 0.810 ppm |
2019 | 0.555 ppm | 4 | 4 | 0.300 ppm - 0.780 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 |
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