Diquat
City of Wilsonville
Diquat is a herbicide used on potato crops and aquatic weeds.
19
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 | 4 | 0 | ND |
| 2019 | ND | 4 | 0 | ND |
| 2020 | ND | 4 | 0 | ND |
| 2021 | ND | 3 | 0 | ND |
| 2022 | ND | 2 | 0 | ND |
| 2023 | ND | 2 | 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 |
|---|---|---|
| 2018-01-10 | 201712040042-S | ND |
| 2018-04-11 | 201803050004-S | ND |
| 2018-07-18 | 201807190944-S | ND |
| 2018-10-10 | 201809030044-S | ND |
| 2019-01-09 | 201812030009-S | ND |
| 2019-04-10 | 201904110241-S | ND |
| 2019-07-10 | 201907110430-S | ND |
| 2019-10-08 | 201910090408-S | ND |
| 2020-01-02 | 202001030119-S | ND |
| 2020-04-15 | 202004160157-S | ND |
| 2020-07-15 | 202007160188-S | ND |
| 2020-10-14 | 202010150105-S | ND |
| 2021-01-06 | 202101070374-S | ND |
| 2021-04-14 | 202104150878-S | ND |
| 2021-07-27 | 202107280247-S | ND |
| 2022-02-02 | 202202030907-S | ND |
| 2022-04-13 | 202204140832-S | ND |
| 2023-01-11 | 380-34174-2-S | ND |
| 2023-06-06 | 380-50204-1-S | ND |