Diquat
Cottonwood WSD
Diquat is a herbicide used on potato crops and aquatic weeds.
24
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 |
|---|---|---|---|---|
| 2014 | ND | 7 | 0 | ND |
| 2015 | ND | 3 | 0 | ND |
| 2016 | ND | 4 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 3 | 0 | ND |
| 2019 | ND | 7 | 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 |
| 2014-05-21 | ND |
| 2014-06-04 | ND |
| 2014-06-04 | ND |
| 2014-08-20 | ND |
| 2014-08-20 | ND |
| 2014-09-23 | ND |
| 2015-05-07 | ND |
| 2015-05-07 | ND |
| 2015-12-01 | ND |
| 2016-09-21 | ND |
| 2016-09-21 | ND |
| 2016-12-15 | ND |
| 2016-12-15 | ND |
| 2018-09-13 | ND |
| 2018-09-13 | ND |
| 2018-09-13 | ND |
| 2019-04-23 | ND |
| 2019-09-10 | ND |
| 2019-09-10 | ND |
| 2019-10-16 | ND |
| 2019-10-16 | ND |
| 2019-10-16 | ND |
| 2019-10-16 | ND |