Nitrate and nitrite
Bristol Water Department
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 | 0.504 ppm | 5 | 3 | ND - 1.30 ppm |
2015 | N/A | 0 | 0 | N/A |
2016 | 0.480 ppm | 5 | 2 | ND - 1.40 ppm |
2017 | 0.773 ppm | 5 | 5 | 0.0507 ppm - 1.60 ppm |
2018 | 0.651 ppm | 5 | 5 | 0.0972 ppm - 1.85 ppm |
2019 | 0.861 ppm | 5 | 5 | 0.111 ppm - 2.42 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 |
---|---|---|
2014-04-03 | E404362-1IOC1 | 0.120 ppm |
2014-07-11 | E407A82-1NOX | ND |
2014-07-11 | E407A82-2NOX | 1.10 ppm |
2014-07-11 | E407A82-3NOX | 1.30 ppm |
2014-07-11 | E407A82-4NOX | ND |
2016-07-08 | E607771-1NOX | ND |
2016-07-08 | E607771-4NOX | ND |
2016-07-08 | E607771-3NOX | 1.000 ppm |
2016-07-08 | E607771-2NOX | 1.40 ppm |
2016-12-08 | E612969-1IOC1 | ND |
2017-03-10 | D7C0838-03NOX | 1.24 ppm |
2017-03-10 | D7C0838-02NOX | 1.60 ppm |
2017-03-10 | D7C0838-04NOX | 0.899 ppm |
2017-03-10 | D7C0838-01NOX | 0.0815 ppm |
2017-07-07 | D7G0496-01NOXR | 0.0507 ppm |
2018-01-10 | D8A0565-01NOX | 0.0972 ppm |
2018-01-10 | D8A0565-04NOX | 0.107 ppm |
2018-01-10 | D8A0565-03NOX | 1.09 ppm |
2018-01-10 | D8A0565-02NOX | 1.85 ppm |
2018-03-07 | D8C0471-01NOXR | 0.117 ppm |
2019-03-27 | D9C2628-01NOX | 0.111 ppm |
2019-03-27 | D9C2628-04NOX | 0.117 ppm |
2019-03-27 | D9C2628-03NOX | 1.54 ppm |
2019-03-27 | D9C2628-02NOX | 2.42 ppm |
2019-03-27 | D9C2626-01IOCR | 0.118 ppm |