Nitrate and nitrite
Metropolitan Utilities District
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.
40
Samples
0
Samples exceeding legal limit (MCL)
40
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 1.10 ppm | 7 | 7 | 0.285 ppm - 3.70 ppm |
| 2015 | 1.35 ppm | 5 | 5 | 0.456 ppm - 2.96 ppm |
| 2016 | 2.32 ppm | 8 | 8 | 0.341 ppm - 5.35 ppm |
| 2017 | 1.50 ppm | 8 | 8 | 0.511 ppm - 3.03 ppm |
| 2018 | 1.42 ppm | 6 | 6 | 0.636 ppm - 2.22 ppm |
| 2019 | 1.53 ppm | 6 | 6 | 0.535 ppm - 2.41 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 |
|---|---|---|
| 2014-03-03 | 280513 | 0.694 ppm |
| 2014-03-03 | 280514 | 0.589 ppm |
| 2014-05-12 | 302598 | 1.37 ppm |
| 2014-06-02 | 295082 | 0.285 ppm |
| 2014-06-02 | 295083 | 0.490 ppm |
| 2014-06-02 | 295086 | 0.604 ppm |
| 2014-06-02 | 295088 | 3.70 ppm |
| 2015-02-23 | 344379 | 0.456 ppm |
| 2015-02-23 | 344378 | 1.72 ppm |
| 2015-02-23 | 344377 | 1.07 ppm |
| 2015-06-08 | 357030 | 2.96 ppm |
| 2015-06-08 | 357027 | 0.534 ppm |
| 2016-03-09 | 0.341 ppm | |
| 2016-03-09 | 2.45 ppm | |
| 2016-03-09 | 5.35 ppm | |
| 2016-04-18 | 3.36 ppm | |
| 2016-06-01 | 2.74 ppm | |
| 2016-06-01 | 0.593 ppm | |
| 2016-08-15 | 0.695 ppm | |
| 2016-10-18 | 3.06 ppm | |
| 2017-01-18 | 2.05 ppm | |
| 2017-03-27 | 0.546 ppm | |
| 2017-03-27 | 3.03 ppm | |
| 2017-04-18 | 1.02 ppm | |
| 2017-04-19 | 1.53 ppm | |
| 2017-04-19 | 1.94 ppm | |
| 2017-07-31 | 0.511 ppm | |
| 2017-11-08 | 1.38 ppm | |
| 2018-01-16 | 531398 | 1.04 ppm |
| 2018-03-26 | 531396 | 0.636 ppm |
| 2018-03-26 | 531397 | 2.22 ppm |
| 2018-05-07 | 545296 | 2.04 ppm |
| 2018-08-07 | 562858 | 0.743 ppm |
| 2018-11-13 | 578858 | 1.82 ppm |
| 2019-02-04 | 591457 | 1.82 ppm |
| 2019-02-27 | 591455 | 0.535 ppm |
| 2019-02-27 | 591456 | 2.41 ppm |
| 2019-04-23 | 604244 | 1.95 ppm |
| 2019-07-22 | 619496 | 1.33 ppm |
| 2019-10-29 | 640637 | 1.14 ppm |