Diquat
City of Ukiah
Diquat is a herbicide used on potato crops and aquatic weeds.
9
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 | 2 | 0 | ND |
| 2017 | ND | 1 | 0 | ND |
| 2018 | ND | 1 | 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 |
|---|---|---|
| 2014-07-08 | 9590-028-1400 | ND |
| 2015-07-22 | 9590-029-1239 | ND |
| 2016-07-26 | 9590-004-1430 | ND |
| 2016-09-13 | 1610-033-1110 | ND |
| 2017-07-26 | 5867-028-1040 | ND |
| 2018-07-25 | 1644-029-1442 | ND |
| 2019-07-31 | 1610-032-0905 | ND |
| 2019-08-06 | 1610-004-1023 | ND |
| 2019-09-03 | 1610-033-1045 | ND |