Diquat
City of Riverside
Diquat is a herbicide used on potato crops and aquatic weeds.
21
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 | 3 | 0 | ND |
| 2016 | ND | 4 | 0 | ND |
| 2017 | ND | 4 | 0 | ND |
| 2018 | ND | 4 | 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 | Lab ID | Result |
|---|---|---|
| 2014-01-21 | 9590-107-0949 | ND |
| 2014-02-18 | 9590-107-0920 | ND |
| 2014-07-15 | 9590-107-0850 | ND |
| 2015-01-20 | 9590-107-1030 | ND |
| 2015-07-14 | 9590-107-0949 | ND |
| 2015-10-28 | 9590-107-1400 | ND |
| 2016-01-26 | 9590-107-0947 | ND |
| 2016-04-19 | 9590-107-1141 | ND |
| 2016-07-12 | 9590-107-1230 | ND |
| 2016-10-04 | 9590-107-1233 | ND |
| 2017-02-28 | 9590-107-0820 | ND |
| 2017-05-02 | 9590-107-1039 | ND |
| 2017-07-25 | 9590-107-1055 | ND |
| 2017-10-03 | 9590-107-0845 | ND |
| 2018-01-02 | 9590-107-0900 | ND |
| 2018-04-03 | 9590-107-0910 | ND |
| 2018-07-03 | 3334-107-1015 | ND |
| 2018-10-03 | 3334-107-0920 | ND |
| 2019-04-02 | 3334-107-0900 | ND |
| 2019-07-02 | 3334-107-0910 | ND |
| 2019-10-01 | 3334-107-1139 | ND |