Diquat
Columbia Water Company
Diquat is a herbicide used on potato crops and aquatic weeds.
12
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 | 6 | 0 | ND |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | ND | 6 | 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 |
|---|---|---|
| 2020-04-07 | 22172791.00 | ND |
| 2020-04-07 | 22172821.00 | ND |
| 2020-04-13 | 22172851.00 | ND |
| 2020-07-06 | 22757674.00 | ND |
| 2020-07-07 | 22757704.00 | ND |
| 2020-07-13 | 22757908.00 | ND |
| 2023-04-04 | 28859616.00 | ND |
| 2023-04-10 | 28859617.00 | ND |
| 2023-04-17 | 28859802.00 | ND |
| 2023-07-10 | 29455566.00 | ND |
| 2023-07-14 | 29455564.00 | ND |
| 2023-07-14 | 29455565.00 | ND |