Diquat
Manatee County Utilities Department
Diquat is a herbicide used on potato crops and aquatic weeds.
16
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 | ND | 4 | 0 | ND |
| 2015 | ND | 3 | 0 | ND |
| 2016 | ND | 3 | 0 | ND |
| 2017 | 0.243 ppb | 4 | 1 | ND - 0.970 ppb |
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 1 | 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 | Result |
|---|---|
| 2014-01-22 | ND |
| 2014-04-16 | ND |
| 2014-07-16 | ND |
| 2014-10-22 | ND |
| 2015-04-15 | ND |
| 2015-07-15 | ND |
| 2015-10-14 | ND |
| 2016-01-20 | ND |
| 2016-07-20 | ND |
| 2016-10-19 | ND |
| 2017-01-18 | 0.970 ppb |
| 2017-04-19 | ND |
| 2017-07-19 | ND |
| 2017-10-18 | ND |
| 2018-01-17 | ND |
| 2019-01-02 | ND |