Diquat
Madison Water Works
Diquat is a herbicide used on potato crops and aquatic weeds.
6
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 |
|---|---|---|---|---|
| 2012 | ND | 2 | 0 | ND |
| 2013 | ND | 3 | 0 | ND |
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | ND | 1 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
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 |
|---|---|---|
| 2012-02-16 | L560993-2 | ND |
| 2012-04-10 | L569265-02 | ND |
| 2013-06-06 | L369831-1 | ND |
| 2013-09-12 | L657239-1 | ND |
| 2013-10-07 | L661777-1 | ND |
| 2015-06-24 | L773174-1 | ND |