Diquat
Castle Rock
Diquat is a herbicide used on potato crops and aquatic weeds.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | ND | 8 | 0 | ND |
2015 | ND | 1 | 0 | ND |
2016 | ND | 5 | 0 | ND |
2017 | ND | 10 | 0 | ND |
2018 | ND | 8 | 0 | ND |
2019 | ND | 8 | 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 |
---|---|
2014-02-04 | ND |
2014-04-29 | ND |
2014-07-21 | ND |
2014-07-22 | ND |
2014-08-25 | ND |
2014-11-19 | ND |
2014-12-04 | ND |
2014-12-04 | ND |
2015-08-05 | ND |
2016-02-23 | ND |
2016-02-24 | ND |
2016-05-23 | ND |
2016-06-27 | ND |
2016-11-14 | ND |
2017-02-21 | ND |
2017-02-21 | ND |
2017-03-22 | ND |
2017-04-18 | ND |
2017-04-18 | ND |
2017-05-16 | ND |
2017-06-21 | ND |
2017-07-17 | ND |
2017-07-17 | ND |
2017-10-18 | ND |
2018-03-20 | ND |
2018-03-20 | ND |
2018-05-21 | ND |
2018-08-30 | ND |
2018-09-13 | ND |
2018-11-16 | ND |
2018-12-12 | ND |
2018-12-12 | ND |
2019-02-07 | ND |
2019-04-17 | ND |
2019-09-16 | ND |
2019-09-16 | ND |
2019-11-05 | ND |
2019-11-25 | ND |
2019-12-11 | ND |
2019-12-11 | ND |