Nitrate and nitrite
Polk County Water Authority
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.
18
Samples
0
Samples exceeding legal limit (MCL)
18
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.607 ppm | 3 | 3 | 0.390 ppm - 0.990 ppm |
| 2015 | 0.650 ppm | 3 | 3 | 0.410 ppm - 1.10 ppm |
| 2016 | 0.597 ppm | 3 | 3 | 0.380 ppm - 0.960 ppm |
| 2017 | 0.697 ppm | 3 | 3 | 0.440 ppm - 1.20 ppm |
| 2018 | 0.730 ppm | 3 | 3 | 0.490 ppm - 1.20 ppm |
| 2019 | 0.667 ppm | 3 | 3 | 0.410 ppm - 1.10 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 |
|---|---|---|
| 2014-08-25 | AI51175 | 0.440 ppm |
| 2014-08-25 | AI51174 | 0.990 ppm |
| 2014-08-25 | AI51173 | 0.390 ppm |
| 2015-07-29 | AI84528 | 1.10 ppm |
| 2015-07-29 | AI84527 | 0.440 ppm |
| 2015-07-29 | AI84526 | 0.410 ppm |
| 2016-08-03 | AJ21017 | 0.960 ppm |
| 2016-08-03 | AJ21019 | 0.450 ppm |
| 2016-08-03 | AJ21018 | 0.380 ppm |
| 2017-08-01 | AJ62523 | 0.440 ppm |
| 2017-08-01 | AJ62522 | 0.450 ppm |
| 2017-08-01 | AJ62521 | 1.20 ppm |
| 2018-08-07 | AJ96698 | 0.490 ppm |
| 2018-08-07 | AJ96697 | 1.20 ppm |
| 2018-08-07 | AJ96696 | 0.500 ppm |
| 2019-07-30 | AK23835 | 1.10 ppm |
| 2019-07-30 | AK23921 | 0.490 ppm |
| 2019-07-30 | AK23920 | 0.410 ppm |