Nitrate and nitrite
Kent Water Department
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.547 ppm | 11 | 6 | ND - 1.60 ppm |
| 2019 | 0.696 ppm | 10 | 9 | ND - 1.20 ppm |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | 0.717 ppm | 9 | 8 | ND - 1.30 ppm |
| 2022 | 0.709 ppm | 8 | 5 | ND - 1.60 ppm |
| 2023 | 0.656 ppm | 7 | 4 | ND - 1.90 ppm |
ppm = parts per million
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 0.14 ppm
The EWG 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 |
|---|---|---|
| 2018-07-16 | ND | |
| 2018-07-16 | 0.640 ppm | |
| 2018-07-16 | ND | |
| 2018-07-16 | 1.60 ppm | |
| 2018-07-16 | ND | |
| 2018-07-16 | ND | |
| 2018-07-16 | ND | |
| 2018-07-16 | 0.580 ppm | |
| 2018-07-17 | 1.20 ppm | |
| 2018-08-07 | 1.000 ppm | |
| 2018-08-07 | 1.000 ppm | |
| 2019-07-02 | 0.680 ppm | |
| 2019-07-02 | 1.20 ppm | |
| 2019-07-02 | 0.700 ppm | |
| 2019-07-12 | 0.620 ppm | |
| 2019-07-12 | 0.620 ppm | |
| 2019-07-16 | 0.670 ppm | |
| 2019-07-16 | 0.670 ppm | |
| 2019-07-22 | 0.900 ppm | |
| 2019-07-22 | 0.900 ppm | |
| 2019-07-23 | ND | |
| 2021-06-23 | 4180800 | 0.910 ppm |
| 2021-06-23 | 4180800 | 0.910 ppm |
| 2021-07-13 | 4212889 | 1.30 ppm |
| 2021-07-13 | 4212888 | 0.750 ppm |
| 2021-07-13 | 4212890 | 0.660 ppm |
| 2021-07-13 | 4212890 | 0.660 ppm |
| 2021-07-20 | 4200153 | 0.630 ppm |
| 2021-07-20 | 4200153 | 0.630 ppm |
| 2021-07-27 | 4203566 | ND |
| 2022-06-21 | 4300525 | 1.60 ppm |
| 2022-07-19 | 4320848 | 0.600 ppm |
| 2022-07-26 | 4326472 | 1.40 ppm |
| 2022-07-26 | 4326474 | ND |
| 2022-07-26 | 4329405 | 1.40 ppm |
| 2022-07-26 | 4326473 | ND |
| 2022-07-26 | 4329412 | 0.670 ppm |
| 2022-07-26 | 4329409 | ND |
| 2023-07-31 | 4506151 | ND |
| 2023-07-31 | 4506152 | 1.90 ppm |
| 2023-07-31 | 4506150 | ND |
| 2023-07-31 | 4511171 | ND |
| 2023-07-31 | 4511172 | 0.800 ppm |
| 2023-07-31 | 4511173 | 1.20 ppm |
| 2023-07-31 | 4511170 | 0.690 ppm |