Diquat
California Water Service (CWS) - King City
Diquat is a herbicide used on potato crops and aquatic weeds.
12
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 | N/A | 0 | 0 | N/A |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 3 | 0 | ND |
| 2017 | ND | 3 | 0 | ND |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | ND | 6 | 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 |
|---|---|---|
| 2016-03-07 | 9590-012-1143 | ND |
| 2016-03-14 | 9590-006-1216 | ND |
| 2016-09-20 | 9590-007-1117 | ND |
| 2017-06-06 | 9590-014-1138 | ND |
| 2017-06-06 | 9590-015-1105 | ND |
| 2017-06-07 | 9590-008-1117 | ND |
| 2019-03-20 | 9590-012-1127 | ND |
| 2019-04-17 | 9590-006-1140 | ND |
| 2019-06-03 | 9590-014-0936 | ND |
| 2019-06-03 | 9590-015-1031 | ND |
| 2019-06-04 | 9590-008-1030 | ND |
| 2019-09-09 | 9590-007-1125 | ND |