Nitrate
Dean Dale Special Utility District
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. 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 | 7.25 ppm | 8 | 8 | 3.57 ppm - 10.2 ppm |
| 2019 | 0.523 ppm | 8 | 8 | 0.372 ppm - 0.626 ppm |
| 2020 | 0.179 ppm | 7 | 7 | 0.126 ppm - 0.226 ppm |
| 2021 | 0.181 ppm | 8 | 8 | 0.0326 ppm - 0.604 ppm |
| 2022 | 0.178 ppm | 8 | 8 | 0.0416 ppm - 0.391 ppm |
| 2023 | 0.240 ppm | 8 | 8 | 0.144 ppm - 0.363 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
The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-02-28 | Q1808445005 | 9.21 ppm |
| 2018-02-28 | Q1808445002 | 10.2 ppm |
| 2018-05-09 | Q1819194003 | 8.39 ppm |
| 2018-05-09 | Q1819194001 | 8.12 ppm |
| 2018-08-23 | Q1834001001 | 6.39 ppm |
| 2018-08-23 | Q1834001002 | 5.99 ppm |
| 2018-11-13 | Q1845721002 | 6.14 ppm |
| 2018-11-13 | Q1845721004 | 3.57 ppm |
| 2019-01-29 | Q1904440002 | 0.561 ppm |
| 2019-01-29 | Q1904440007 | 0.553 ppm |
| 2019-05-16 | Q1926563001 | 0.619 ppm |
| 2019-05-16 | Q1926563002 | 0.626 ppm |
| 2019-08-20 | Q1957381002 | 0.372 ppm |
| 2019-08-20 | Q1957381001 | 0.408 ppm |
| 2019-11-21 | Q1977788001 | 0.575 ppm |
| 2019-11-21 | Q1977788002 | 0.472 ppm |
| 2020-03-03 | Q2007978004 | 0.226 ppm |
| 2020-03-03 | Q2007978010 | 0.221 ppm |
| 2020-06-09 | Q2023220001 | 0.156 ppm |
| 2020-09-22 | Q2037564001 | 0.184 ppm |
| 2020-09-22 | Q2037564002 | 0.126 ppm |
| 2020-11-30 | Q2047189003 | 0.171 ppm |
| 2020-11-30 | Q2047189004 | 0.170 ppm |
| 2021-03-10 | Q2106377001 | 0.0354 ppm |
| 2021-03-10 | Q2106377002 | 0.0326 ppm |
| 2021-06-15 | Q2115601003 | 0.0611 ppm |
| 2021-06-15 | Q2115601004 | 0.0543 ppm |
| 2021-09-15 | Q2125322001 | 0.0600 ppm |
| 2021-09-15 | Q2125322002 | 0.450 ppm |
| 2021-11-02 | Q2130740001 | 0.152 ppm |
| 2021-11-02 | Q2130740002 | 0.604 ppm |
| 2022-01-20 | Q2202094005 | 0.149 ppm |
| 2022-01-20 | Q2202094006 | 0.148 ppm |
| 2022-04-12 | Q2211206002 | 0.0457 ppm |
| 2022-04-12 | Q2211206003 | 0.0416 ppm |
| 2022-07-12 | Q2219478001 | 0.176 ppm |
| 2022-07-12 | Q2219478004 | 0.161 ppm |
| 2022-10-05 | Q2230107002 | 0.309 ppm |
| 2022-10-05 | Q2230107003 | 0.391 ppm |
| 2023-02-13 | Q2305500001 | 0.176 ppm |
| 2023-02-13 | Q2305500004 | 0.144 ppm |
| 2023-05-10 | Q2317964001 | 0.292 ppm |
| 2023-05-10 | Q2317964002 | 0.278 ppm |
| 2023-08-29 | Q2337352001 | 0.175 ppm |
| 2023-08-29 | Q2337352004 | 0.176 ppm |
| 2023-10-31 | Q2346589001 | 0.363 ppm |
| 2023-10-31 | Q2346589002 | 0.312 ppm |