Nitrate
Toronto Public Water System
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.890 ppm | 12 | 12 | 0.670 ppm - 1.25 ppm |
| 2015 | 0.921 ppm | 12 | 12 | 0.700 ppm - 1.48 ppm |
| 2016 | 0.859 ppm | 12 | 11 | ND - 1.20 ppm |
| 2017 | 0.861 ppm | 12 | 12 | 0.620 ppm - 1.10 ppm |
| 2018 | 1.15 ppm | 11 | 10 | ND - 5.40 ppm |
| 2019 | 0.952 ppm | 10 | 10 | 0.666 ppm - 1.22 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EWG Health Guideline 0.14 ppm
The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.
EPA Maximum Contaminant
Level (MCL) 10 ppm
The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-14 | A140170224 | 1.25 ppm |
| 2014-02-11 | A140112308 | 0.920 ppm |
| 2014-03-12 | A140187026 | 0.910 ppm |
| 2014-04-08 | A140187027 | 0.840 ppm |
| 2014-05-13 | A140201628 | 0.670 ppm |
| 2014-06-10 | A140104373 | 1.05 ppm |
| 2014-07-08 | A140161410 | 0.800 ppm |
| 2014-08-12 | A140213228 | 0.680 ppm |
| 2014-09-09 | A140201933 | 0.900 ppm |
| 2014-10-14 | A140240511 | 1.12 ppm |
| 2014-11-11 | A140213302 | 0.740 ppm |
| 2014-12-09 | A140193876 | 0.800 ppm |
| 2015-01-13 | A150258009 | 0.750 ppm |
| 2015-02-10 | A150265221 | 1.05 ppm |
| 2015-03-10 | A150236096 | 1.10 ppm |
| 2015-04-14 | A150242727 | 0.840 ppm |
| 2015-05-12 | A150291966 | 0.800 ppm |
| 2015-06-09 | A150259176 | 0.860 ppm |
| 2015-07-14 | A150259177 | 0.700 ppm |
| 2015-08-11 | A150124489 | 0.790 ppm |
| 2015-09-08 | A150258085 | 1.04 ppm |
| 2015-10-13 | A150206834 | 1.48 ppm |
| 2015-11-10 | A150334570 | 0.740 ppm |
| 2015-12-08 | A150350188 | 0.900 ppm |
| 2016-01-12 | A160350186 | 1.06 ppm |
| 2016-02-09 | A160294398 | 0.980 ppm |
| 2016-03-08 | A160350189 | 0.870 ppm |
| 2016-04-12 | A160350190 | 0.630 ppm |
| 2016-05-10 | A160381165 | ND |
| 2016-06-07 | A160381248 | 0.980 ppm |
| 2016-07-05 | A160374119 | 0.840 ppm |
| 2016-08-02 | A160376902 | 0.860 ppm |
| 2016-09-06 | A160374120 | 0.960 ppm |
| 2016-10-04 | A160430796 | 1.20 ppm |
| 2016-11-01 | A160444081 | 1.03 ppm |
| 2016-12-13 | A160452826 | 0.900 ppm |
| 2017-01-10 | A170343049 | 0.880 ppm |
| 2017-02-07 | A170462838 | 1.10 ppm |
| 2017-03-07 | A170460577 | 0.880 ppm |
| 2017-04-04 | A170448835 | 0.780 ppm |
| 2017-05-02 | A170490858 | 0.620 ppm |
| 2017-06-06 | A170490875 | 0.810 ppm |
| 2017-07-11 | A170511468 | 0.780 ppm |
| 2017-08-08 | A170521321 | 0.950 ppm |
| 2017-09-05 | A170361022 | 0.900 ppm |
| 2017-10-03 | A170277845 | 0.950 ppm |
| 2017-11-07 | A170533771 | 0.740 ppm |
| 2017-12-05 | A170547820 | 0.940 ppm |
| 2018-01-02 | A180557910 | 0.770 ppm |
| 2018-02-06 | A180560674 | 0.890 ppm |
| 2018-03-06 | A180577833 | 0.700 ppm |
| 2018-04-03 | A180583082 | 0.800 ppm |
| 2018-05-01 | A180575118 | 0.750 ppm |
| 2018-06-05 | A180597250 | 0.700 ppm |
| 2018-07-10 | A180620118 | 0.950 ppm |
| 2018-08-07 | A180503926 | 0.850 ppm |
| 2018-09-04 | A180625826 | 5.40 ppm |
| 2018-10-02 | A180640217 | ND |
| 2018-12-04 | 8L00136-01 | 0.826 ppm |
| 2019-01-03 | 9A00348-01 | 0.819 ppm |
| 2019-02-05 | 9B00345-01 | 0.942 ppm |
| 2019-03-05 | 9C00339-01 | 0.926 ppm |
| 2019-04-02 | 9D00163-01 | 0.887 ppm |
| 2019-05-07 | 9E00886-01 | 0.921 ppm |
| 2019-06-04 | 9F00146-01 | 0.904 ppm |
| 2019-07-02 | 9G00191-01 | 0.666 ppm |
| 2019-08-06 | 9H00644-01 | 1.10 ppm |
| 2019-09-03 | 9I00148-01 | 1.13 ppm |
| 2019-10-08 | 9J01191-01 | 1.22 ppm |