Nitrate and nitrite
City of Chicago
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.
12
Samples
0
Samples exceeding legal limit (MCL)
12
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.306 ppm | 2 | 2 | 0.304 ppm - 0.308 ppm |
| 2015 | 0.290 ppm | 2 | 2 | 0.280 ppm - 0.299 ppm |
| 2016 | 0.434 ppm | 2 | 2 | 0.405 ppm - 0.462 ppm |
| 2017 | 0.340 ppm | 2 | 2 | 0.321 ppm - 0.359 ppm |
| 2018 | 0.365 ppm | 2 | 2 | 0.314 ppm - 0.416 ppm |
| 2019 | 0.340 ppm | 2 | 2 | 0.330 ppm - 0.350 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 |
|---|---|---|
| 2014-05-13 | SE40612-01_01 | 0.304 ppm |
| 2014-05-13 | SE40612-02_01 | 0.308 ppm |
| 2015-06-01 | SF50061-01_01 | 0.299 ppm |
| 2015-06-01 | SF50061-02_01 | 0.280 ppm |
| 2016-05-03 | 16E0144-01_01 | 0.462 ppm |
| 2016-05-03 | 16E0144-02_01 | 0.405 ppm |
| 2017-05-02 | 17E0094-01_01 | 0.321 ppm |
| 2017-05-02 | 17E0094-02_01 | 0.359 ppm |
| 2018-04-24 | 18D0575-01_01 | 0.314 ppm |
| 2018-04-24 | 18D0575-02_01 | 0.416 ppm |
| 2019-05-21 | 19E0705-01 | 0.330 ppm |
| 2019-05-21 | 19E0705-02 | 0.350 ppm |