Diquat
Widefield WSD
Diquat is a herbicide used on potato crops and aquatic weeds.
34
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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | ND | 2 | 0 | ND |
| 2015 | ND | 4 | 0 | ND |
| 2016 | ND | 11 | 0 | ND |
| 2017 | ND | 2 | 0 | ND |
| 2018 | ND | 5 | 0 | ND |
| 2019 | ND | 10 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
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 | Result |
|---|---|
| 2014-03-12 | ND |
| 2014-03-19 | ND |
| 2015-06-08 | ND |
| 2015-06-09 | ND |
| 2015-09-23 | ND |
| 2015-09-29 | ND |
| 2016-05-02 | ND |
| 2016-05-02 | ND |
| 2016-05-02 | ND |
| 2016-05-02 | ND |
| 2016-05-02 | ND |
| 2016-06-15 | ND |
| 2016-08-08 | ND |
| 2016-08-08 | ND |
| 2016-08-23 | ND |
| 2016-08-23 | ND |
| 2016-09-06 | ND |
| 2017-01-18 | ND |
| 2017-05-24 | ND |
| 2018-08-21 | ND |
| 2018-08-21 | ND |
| 2018-08-21 | ND |
| 2018-11-26 | ND |
| 2018-11-27 | ND |
| 2019-05-06 | ND |
| 2019-05-28 | ND |
| 2019-05-28 | ND |
| 2019-07-17 | ND |
| 2019-07-29 | ND |
| 2019-07-29 | ND |
| 2019-09-09 | ND |
| 2019-09-11 | ND |
| 2019-11-13 | ND |
| 2019-12-03 | ND |