Nitrate and nitrite
Toronto Public Water System
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.
70
Samples
0
Samples exceeding legal limit (MCL)
68
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 | 0.737 ppm | 12 | 11 | ND - 0.950 ppm |
| 2019 | 0.952 ppm | 10 | 10 | 0.670 ppm - 1.22 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 |
|---|---|---|
| 2014-01-14 | 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 | 0.900 ppm |
| 2018-10-02 | A180640217 | ND |
| 2018-11-06 | 8K00560-01 | 0.700 ppm |
| 2018-12-04 | 8L00136-01 | 0.830 ppm |
| 2019-01-03 | 9A00348-01 | 0.820 ppm |
| 2019-02-05 | 9B00345-01 | 0.940 ppm |
| 2019-03-05 | 9C00339-01 | 0.930 ppm |
| 2019-04-02 | 9D00163-01 | 0.890 ppm |
| 2019-05-07 | 9E00886-01 | 0.920 ppm |
| 2019-06-04 | 9F00146-01 | 0.900 ppm |
| 2019-07-02 | 9G00191-01 | 0.670 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 |