Diquat
Long Beach UtilitiesDepartment
Diquat is a herbicide used on potato crops and aquatic weeds.
8
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 | 2 | 0 | ND |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | ND | 2 | 0 | ND |
| 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 |
|---|---|---|
| 2019-01-24 | CA1910065_039_039-201901241135 | ND |
| 2019-09-11 | CA1910065_039_039-201909111041 | ND |
| 2022-07-01 | CA1910065_045_045-202207010838 | ND |
| 2022-09-22 | CA1910065_066_066-202209221415 | ND |
| 2023-06-08 | CA1910065_066_066-202306081014 | ND |
| 2023-08-10 | CA1910065_066_066-202308100950 | ND |
| 2023-10-12 | CA1910065_066_066-202310121215 | ND |
| 2023-12-21 | CA1910065_039_039-202312211017 | ND |