Diquat
Johnson Utilities
Diquat is a herbicide used on potato crops and aquatic weeds.
18
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 | N/A | 0 | 0 | N/A |
| 2015 | ND | 4 | 0 | ND |
| 2016 | ND | 2 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 12 | 0 | ND |
| 2019 | 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 |
|---|---|---|
| 2015-03-04 | 201503040395SB | ND |
| 2015-03-04 | 201503040395SA | ND |
| 2015-06-17 | 201506170582SB | ND |
| 2015-06-17 | 201506170582SA | ND |
| 2016-02-17 | 201602180080S | ND |
| 2016-10-27 | 201610270264S | ND |
| 2018-02-01 | 201802020007SB | ND |
| 2018-02-01 | 201802020007SD | ND |
| 2018-02-01 | 201802020007SC | ND |
| 2018-02-01 | 201802020007SA | ND |
| 2018-02-06 | 201802060709SB | ND |
| 2018-02-06 | 201802060709SA | ND |
| 2018-05-21 | 201805220092S | ND |
| 2018-05-21 | 201805220096SE | ND |
| 2018-05-21 | 201805220096SD | ND |
| 2018-05-21 | 201805220096SC | ND |
| 2018-05-21 | 201805220096SB | ND |
| 2018-05-21 | 201805220096SA | ND |