Diquat
Clearwater Water System
Diquat is a herbicide used on potato crops and aquatic weeds.
24
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 | 3 | 0 | ND |
| 2015 | ND | 4 | 0 | ND |
| 2016 | ND | 5 | 0 | ND |
| 2017 | ND | 6 | 0 | ND |
| 2018 | ND | 3 | 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 | Result |
|---|---|
| 2014-02-13 | ND |
| 2014-08-14 | ND |
| 2014-08-14 | ND |
| 2015-01-13 | ND |
| 2015-01-13 | ND |
| 2015-05-07 | ND |
| 2015-07-29 | ND |
| 2016-01-25 | ND |
| 2016-01-25 | ND |
| 2016-01-25 | ND |
| 2016-04-27 | ND |
| 2016-07-20 | ND |
| 2017-05-11 | ND |
| 2017-05-16 | ND |
| 2017-05-16 | ND |
| 2017-10-02 | ND |
| 2017-10-02 | ND |
| 2017-10-02 | ND |
| 2018-02-26 | ND |
| 2018-02-26 | ND |
| 2018-02-26 | ND |
| 2019-02-05 | ND |
| 2019-02-05 | ND |
| 2019-02-05 | ND |