Diquat
Freeport
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 | 3 | 0 | ND |
| 2015 | ND | 5 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 6 | 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 |
|---|---|---|
| 2014-05-19 | 1405A33-001A | ND |
| 2014-07-15 | 1407A33-003A | ND |
| 2014-10-29 | 1410G35-003A | ND |
| 2015-01-20 | 1501B51-002A | ND |
| 2015-01-20 | 1501B51-005A | ND |
| 2015-01-20 | 1501B51-007A | ND |
| 2015-05-26 | 1505K11-003A | ND |
| 2015-05-26 | 1505K11-006A | ND |
| 2018-01-09 | 1801626-003A | ND |
| 2018-01-09 | 1801626-006A | ND |
| 2018-01-09 | 1801626-009A | ND |
| 2018-04-10 | 1804878-003A | ND |
| 2018-04-10 | 1804878-006A | ND |
| 2018-04-10 | 1804878-009A | ND |