Diquat
Upper Hanover Water Authority
Diquat is a herbicide used on potato crops and aquatic weeds.
20
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 | N/A | 0 | 0 | N/A |
| 2020 | ND | 7 | 0 | ND |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | ND | 13 | 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 |
|---|---|---|
| 2020-03-20 | 21847978.00 | ND |
| 2020-03-20 | 21847976.00 | ND |
| 2020-03-20 | 21847977.00 | ND |
| 2020-06-18 | 22417351.00 | ND |
| 2020-06-18 | 22417354.00 | ND |
| 2020-06-18 | 22417352.00 | ND |
| 2020-06-18 | 22417353.00 | ND |
| 2023-02-28 | 28703074.00 | ND |
| 2023-02-28 | 28703076.00 | ND |
| 2023-02-28 | 28703075.00 | ND |
| 2023-05-24 | 29108931.00 | ND |
| 2023-05-24 | 29108933.00 | ND |
| 2023-05-24 | 29108932.00 | ND |
| 2023-08-21 | 29700636.00 | ND |
| 2023-08-21 | 29700635.00 | ND |
| 2023-08-22 | 29700637.00 | ND |
| 2023-11-13 | 30246610.00 | ND |
| 2023-11-13 | 30246582.00 | ND |
| 2023-11-14 | 30246554.00 | ND |
| 2023-11-28 | 30246526.00 | ND |