Diquat
Cecilia Water Corporation
Diquat is a herbicide used on potato crops and aquatic weeds.
21
Samples
0
Samples exceeding legal limit (MCL)
0
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | ND | 6 | 0 | ND |
| 2020 | ND | 5 | 0 | ND |
| 2021 | ND | 4 | 0 | ND |
| 2022 | 0.0667 ppb | 3 | 1 | ND - 0.200 ppb |
| 2023 | ND | 3 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 6 ppb
The EWG Health Guideline of 6 ppb for diquat was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cataracts.
EPA Maximum Contaminant
Level (MCL): 20 ppb
The legal limit for diquat, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2019-02-18 | 35449808002 | ND |
| 2019-02-18 | 35449808003 | ND |
| 2019-02-18 | 35449808001 | ND |
| 2019-02-18 | 35449808002 | ND |
| 2019-02-18 | 35449808003 | ND |
| 2019-02-18 | 35449808001 | ND |
| 2020-03-30 | 35540639001 | ND |
| 2020-09-28 | 35581253002 | ND |
| 2020-09-28 | 35581253003 | ND |
| 2020-12-07 | 35597474004 | ND |
| 2020-12-07 | 35597474003 | ND |
| 2021-02-01 | 35608904003 | ND |
| 2021-02-01 | 35608904004 | ND |
| 2021-05-03 | 35630992003 | ND |
| 2021-05-03 | 35630992004 | ND |
| 2022-01-31 | 35694190001 | ND |
| 2022-01-31 | 35694190002 | ND |
| 2022-01-31 | 35694190003 | 0.200 ppb |
| 2023-02-13 | 35779756005 | ND |
| 2023-11-06 | 35840310001 | ND |
| 2023-11-06 | 35840310002 | ND |