Diquat
Smackover Waterworks
Diquat is a herbicide used on potato crops and aquatic weeds.
11
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 | ND | 1 | 0 | ND |
| 2019 | N/A | 0 | 0 | N/A |
| 2020 | ND | 4 | 0 | ND |
| 2021 | ND | 2 | 0 | ND |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | ND | 4 | 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 |
|---|---|---|
| 2018-05-22 | 18144007408 | ND |
| 2020-01-27 | 20030004506 | ND |
| 2020-01-27 | 20030004606 | ND |
| 2020-06-01 | 20156008407 | ND |
| 2020-06-01 | 20156008507 | ND |
| 2021-03-08 | 21070008307 | ND |
| 2021-06-07 | 21161000107 | ND |
| 2023-01-31 | O205869-QUA-1 | ND |
| 2023-01-31 | O205868-QUA-1 | ND |
| 2023-05-31 | O209480-QUA-1 | ND |
| 2023-05-31 | O209479-QUA-1 | ND |