Diquat
Wattsville Water Authority
Diquat is a herbicide used on potato crops and aquatic weeds.
16
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 | 7 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
| 2020 | ND | 1 | 0 | ND |
| 2021 | ND | 7 | 0 | ND |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | N/A | 0 | 0 | N/A |
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 |
|---|---|---|
| 2018-01-08 | 1801-00078-1 | ND |
| 2018-01-08 | 1801-00078-2 | ND |
| 2018-01-08 | 1801-00078-4 | ND |
| 2018-05-14 | 1805-00261-4 | ND |
| 2018-08-16 | 1808-00271-001 | ND |
| 2018-08-16 | 1808-00271-002 | ND |
| 2018-08-16 | 1808-00271-003 | ND |
| 2019-04-23 | 1904-00356-003 | ND |
| 2020-04-21 | 2004-00292-004 | ND |
| 2021-01-06 | 2101-00069-001 | ND |
| 2021-01-06 | 2101-00069-002 | ND |
| 2021-01-06 | 2101-00069-004 | ND |
| 2021-05-14 | 2105-00311-003 | ND |
| 2021-08-09 | 2108-00147-001 | ND |
| 2021-08-09 | 2108-00147-002 | ND |
| 2021-08-09 | 2108-00147-003 | ND |