Nitrate and nitrite
City of Norfolk
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 |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 0.104 ppm | 8 | 8 | 0.0300 ppm - 0.180 ppm |
2015 | 0.110 ppm | 8 | 8 | 0.0200 ppm - 0.230 ppm |
2016 | 0.129 ppm | 8 | 8 | 0.0400 ppm - 0.200 ppm |
2017 | 0.156 ppm | 8 | 8 | 0.0800 ppm - 0.270 ppm |
2018 | 0.134 ppm | 8 | 8 | 0.0800 ppm - 0.190 ppm |
2019 | 0.151 ppm | 8 | 8 | 0.0500 ppm - 0.200 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 |
---|---|---|
2014-02-11 | 14026243-NIT | 0.0300 ppm |
2014-02-11 | 14026242-NIT | 0.0600 ppm |
2014-05-13 | 14050227-NIT | 0.170 ppm |
2014-05-13 | 14050226-NIT | 0.180 ppm |
2014-08-12 | 14083425-NIT | 0.140 ppm |
2014-08-12 | 14083424-NIT | 0.170 ppm |
2014-11-12 | 14116687-NIT | 0.0500 ppm |
2014-11-12 | 14116688-NIT | 0.0300 ppm |
2015-02-10 | 00225-CITY OF NO | 0.0300 ppm |
2015-02-10 | 00225-CITY OF NO | 0.0200 ppm |
2015-05-12 | 00225-CITY OF NO | 0.120 ppm |
2015-05-12 | 00225-CITY OF NO | 0.110 ppm |
2015-08-11 | 00225-CITY OF NO | 0.230 ppm |
2015-08-11 | 00225-CITY OF NO | 0.210 ppm |
2015-11-09 | 00225-CITY OF NO | 0.0800 ppm |
2015-11-09 | 00225-CITY OF NO | 0.0800 ppm |
2016-02-09 | 16022730-NIT | 0.0400 ppm |
2016-02-09 | 16022726-NIT | 0.0700 ppm |
2016-05-10 | 16055885-NIT | 0.0900 ppm |
2016-05-10 | 16055884-NIT | 0.1000 ppm |
2016-08-09 | 16089081-NIT | 0.180 ppm |
2016-08-09 | 16089080-NIT | 0.200 ppm |
2016-11-08 | 16112156-NIT | 0.180 ppm |
2016-11-08 | 16112158-NIT | 0.170 ppm |
2017-02-14 | 17025478-NIT | 0.260 ppm |
2017-02-14 | 17025477-NIT | 0.270 ppm |
2017-05-09 | 17058218-NIT | 0.1000 ppm |
2017-05-09 | 17058220-NIT | 0.0800 ppm |
2017-08-08 | 17081353-NIT | 0.190 ppm |
2017-08-08 | 17081355-NIT | 0.190 ppm |
2017-11-14 | 17114481-NIT | 0.0800 ppm |
2017-11-14 | 17114486-NIT | 0.0800 ppm |
2018-02-13 | 18027239-NIT | 0.1000 ppm |
2018-02-13 | 18027215-NIT | 0.1000 ppm |
2018-05-08 | 18059821-NIT | 0.190 ppm |
2018-05-08 | 18059847-NIT | 0.180 ppm |
2018-08-14 | 18083056-NIT | 0.160 ppm |
2018-08-14 | 18083076-NIT | 0.140 ppm |
2018-11-13 | 18115916-NIT | 0.120 ppm |
2018-11-13 | 18115938-NIT | 0.0800 ppm |
2019-02-12 | 19028664-NIT | 0.200 ppm |
2019-02-12 | 19028692-NIT | 0.190 ppm |
2019-05-14 | 19052478-NIT | 0.180 ppm |
2019-05-14 | 19052501-NIT | 0.190 ppm |
2019-08-13 | 19085323-NIT | 0.180 ppm |
2019-08-13 | 19085352-NIT | 0.160 ppm |
2019-11-12 | 19118086-NIT | 0.0500 ppm |
2019-11-12 | 19118056-NIT | 0.0600 ppm |