Diquat
Woodland-davis Clean Water Agency
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 | N/A | 0 | 0 | N/A |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 3 | 0 | ND |
| 2017 | ND | 4 | 0 | ND |
| 2018 | ND | 4 | 0 | ND |
| 2019 | ND | 2 | 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 |
|---|---|---|
| 2016-05-24 | 5810-002-1055 | ND |
| 2016-07-13 | 5810-002-0930 | ND |
| 2016-11-09 | 5810-002-1200 | ND |
| 2017-01-12 | 5810-002-1030 | ND |
| 2017-05-10 | 5810-002-1130 | ND |
| 2017-07-12 | 5810-002-1202 | ND |
| 2017-10-11 | 5810-002-1153 | ND |
| 2018-01-09 | 5810-002-1204 | ND |
| 2018-05-09 | 5810-002-1100 | ND |
| 2018-07-11 | 5810-002-1341 | ND |
| 2018-10-10 | 5810-002-1045 | ND |
| 2019-01-09 | 5810-002-1040 | ND |
| 2019-04-10 | 5810-002-1217 | ND |