Nitrate and nitrite
Metropolitan DWID
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 | 1.67 ppm | 23 | 23 | 0.720 ppm - 3.50 ppm |
2015 | 1.73 ppm | 3 | 3 | 1.20 ppm - 2.30 ppm |
2016 | N/A | 0 | 0 | N/A |
2017 | 1.83 ppm | 6 | 6 | 1.20 ppm - 3.30 ppm |
2018 | 0.810 ppm | 3 | 3 | 0.390 ppm - 1.50 ppm |
2019 | 1.78 ppm | 23 | 23 | 0.640 ppm - 4.60 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 |
---|---|---|
2014-10-14 | 14J0544-05(2I) | 0.820 ppm |
2014-10-14 | 14J0544-04(2I) | 3.40 ppm |
2014-10-14 | 14J0544-03(2I) | 0.720 ppm |
2014-10-14 | 14J0544-02(2I) | 1.90 ppm |
2014-10-14 | 14J0544-01(2I) | 2.10 ppm |
2014-10-15 | 14J0566-05(2I) | 0.980 ppm |
2014-10-15 | 14J0566-04(2I) | 1.20 ppm |
2014-10-15 | 14J0566-03(2I) | 1.70 ppm |
2014-10-15 | 14J0566-02(2I) | 1.70 ppm |
2014-10-15 | 14J0566-01(2I) | 1.30 ppm |
2014-10-21 | 14J0685-04(2I) | 1.40 ppm |
2014-10-21 | 14J0681-01(2I) | 2.30 ppm |
2014-10-21 | 14J0685-01(2I) | 1.40 ppm |
2014-10-21 | 14J0685-02(2I) | 1.80 ppm |
2014-10-21 | 14J0685-03(2I) | 2.10 ppm |
2014-10-21 | 14J0685-05(2I) | 1.30 ppm |
2014-10-21 | 14J0685-06(2I) | 3.50 ppm |
2014-10-21 | 14J0685-07(2I) | 2.00 ppm |
2014-10-22 | 14J0707-05(2I) | 1.20 ppm |
2014-10-22 | 14J0707-04(2I) | 2.10 ppm |
2014-10-22 | 14J0707-03(2I) | 0.970 ppm |
2014-10-22 | 14J0707-02(2I) | 1.20 ppm |
2014-10-22 | 14J0707-01(2I) | 1.30 ppm |
2015-10-21 | 15J0666-05(2I) | 2.30 ppm |
2015-10-21 | 15J0666-04(2I) | 1.70 ppm |
2015-10-21 | 15J0666-02(2I) | 1.20 ppm |
2017-08-16 | 17H0609-02(2I) | 2.30 ppm |
2017-08-16 | 17H0609-01(2I) | 1.40 ppm |
2017-10-24 | 550-92026-4 | 3.30 ppm |
2017-10-24 | 550-92026-3 | 1.20 ppm |
2017-10-24 | 550-92026-2 | 1.50 ppm |
2017-10-24 | 550-92026-1 | 1.30 ppm |
2018-05-02 | 20180507088 I | 0.390 ppm |
2018-06-19 | 550-104623-1 | 0.540 ppm |
2018-10-09 | 18J0330-01(2I) | 1.50 ppm |
2019-10-08 | 19J0317-04(2I) | 1.10 ppm |
2019-10-08 | 19J0317-03(2I) | 1.20 ppm |
2019-10-08 | 19J0317-02(2I) | 2.30 ppm |
2019-10-08 | 19J0317-01(2I) | 3.10 ppm |
2019-10-09 | 19J0344-03(2I) | 1.20 ppm |
2019-10-09 | 19J0344-02(2I) | 0.800 ppm |
2019-10-09 | 19J0344-01(2I) | 1.60 ppm |
2019-10-15 | 19J0428-01(2I) | 4.60 ppm |
2019-10-15 | 19J0427-01(2I) | 0.820 ppm |
2019-10-15 | 19J0427-02(2I) | 2.40 ppm |
2019-10-22 | 19J0557-05(2I) | 1.50 ppm |
2019-10-22 | 19J0557-04(2I) | 1.30 ppm |
2019-10-22 | 19J0557-03(2I) | 1.40 ppm |
2019-10-22 | 19J0557-02(2I) | 1.90 ppm |
2019-10-22 | 19J0557-01(2I) | 2.50 ppm |
2019-10-29 | 19J0705-05(21) | 1.30 ppm |
2019-10-29 | 19J0705-04(21) | 0.960 ppm |
2019-10-29 | 19J0705-03(21) | 1.30 ppm |
2019-10-29 | 19J0705-02(21) | 1.80 ppm |
2019-10-29 | 19J0705-01(21) | 1.70 ppm |
2019-11-05 | 19K0107-01(2I) | 4.30 ppm |
2019-12-23 | 19L0630-01(21) | 1.30 ppm |
2019-12-23 | 19L0632-01(21) | 0.640 ppm |