Diquat
Gowc North Water System
Diquat is a herbicide used on potato crops and aquatic weeds.
17
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 | 1 | 0 | ND |
| 2021 | ND | 3 | 0 | ND |
| 2022 | ND | 7 | 0 | ND |
| 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 |
|---|---|---|
| 2020-12-02 | 35596280001 | ND |
| 2021-02-01 | 35608834004 | ND |
| 2021-05-03 | 35630681004 | ND |
| 2021-05-03 | 35630681005 | ND |
| 2022-02-09 | 35696474004EF | ND |
| 2022-02-09 | 35696474003EF | ND |
| 2022-04-04 | 35708518004 | ND |
| 2022-04-04 | 35708518003 | ND |
| 2022-09-27 | 35750438002 | ND |
| 2022-10-24 | 35755885002 | ND |
| 2022-10-24 | 35755885001 | ND |
| 2023-02-22 | 35781903001 | ND |
| 2023-02-22 | 35781903006 | ND |
| 2023-04-03 | 35790249001 | ND |
| 2023-04-03 | 35790249002 | ND |
| 2023-07-10 | 35812564001 | ND |
| 2023-07-10 | 35812564002 | ND |