Diquat
City of Greenfield
Diquat is a herbicide used on potato crops and aquatic weeds.
14
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 | 1 | 0 | ND |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 3 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 2 | 0 | ND |
| 2019 | ND | 8 | 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 |
|---|---|---|
| 2014-01-14 | 5810-001-1000 | ND |
| 2016-01-19 | 5867-001-1000 | ND |
| 2016-01-19 | 5867-006-1020 | ND |
| 2016-01-19 | 5867-010-1040 | ND |
| 2018-02-20 | 5810-001-1000 | ND |
| 2018-02-20 | 5810-010-1040 | ND |
| 2019-01-08 | 5810-006-0950 | ND |
| 2019-03-26 | 5810-001-0920 | ND |
| 2019-06-11 | 5810-001-0945 | ND |
| 2019-06-11 | 5810-006-1000 | ND |
| 2019-06-11 | 5810-010-0930 | ND |
| 2019-07-09 | 5810-010-0900 | ND |
| 2019-10-08 | 5810-001-1000 | ND |
| 2019-12-10 | 5810-010-1020 | ND |