Diquat
Grayson County Water District
Diquat is a herbicide used on potato crops and aquatic weeds.
13
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 | 1 | 0 | ND |
| 2015 | ND | 1 | 0 | ND |
| 2016 | ND | 1 | 0 | ND |
| 2017 | ND | 3 | 0 | ND |
| 2018 | ND | 4 | 0 | ND |
| 2019 | ND | 3 | 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 | Lab ID | Result |
|---|---|---|
| 2014-05-20 | 3031117 | ND |
| 2015-05-12 | 3242472 | ND |
| 2016-05-26 | 3461364 | ND |
| 2017-05-17 | 3697679 | ND |
| 2017-08-31 | 3772095 | ND |
| 2017-11-08 | 3818630 | ND |
| 2018-02-13 | 3871486 | ND |
| 2018-05-09 | 3933808 | ND |
| 2018-08-07 | 4014389 | ND |
| 2018-11-06 | 4113093 | ND |
| 2019-02-07 | 4191520 | ND |
| 2019-08-06 | 4377835 | ND |
| 2019-11-13 | 4485219 | ND |