Diquat
City of Columbia
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 |
|---|---|---|---|---|
| 2014 | ND | 2 | 0 | ND |
| 2015 | ND | 2 | 0 | ND |
| 2016 | ND | 2 | 0 | ND |
| 2017 | ND | 2 | 0 | ND |
| 2018 | ND | 2 | 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 |
|---|---|---|
| 2014-01-15 | AD34535 | ND |
| 2014-01-15 | AD34536 | ND |
| 2015-01-15 | AD50347 | ND |
| 2015-01-15 | AD50348 | ND |
| 2016-01-13 | AD69192 | ND |
| 2016-01-13 | AD69191 | ND |
| 2017-01-17 | AD88356 | ND |
| 2017-03-07 | AD90717 | ND |
| 2018-03-12 | AE09073 | ND |
| 2018-07-16 | AE15003 | ND |
| 2019-01-08 | AE23570 | ND |
| 2019-07-16 | AE33661 | ND |