Diquat
Thousand Trails San Benito Preserve
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 |
|---|---|---|---|---|
| 2018 | ND | 11 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | ND | 2 | 0 | ND |
| 2023 | N/A | 0 | 0 | N/A |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
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 |
|---|---|---|
| 2018-03-28 | CA3500505_001_001-201803281545 | ND |
| 2018-03-28 | CA3500505_002_002-201803281502 | ND |
| 2018-06-21 | CA3500505_001_001-201806211103 | ND |
| 2018-06-21 | CA3500505_002_002-201806211138 | ND |
| 2018-06-26 | CA3500505_005_005-201806260730 | ND |
| 2018-08-08 | CA3500505_005_005-201808080712 | ND |
| 2018-08-08 | CA3500505_001_001-201808080856 | ND |
| 2018-08-08 | CA3500505_002_002-201808080816 | ND |
| 2018-11-14 | CA3500505_001_001-201811141230 | ND |
| 2018-11-14 | CA3500505_005_005-201811141030 | ND |
| 2018-11-27 | CA3500505_002_002-201811271215 | ND |
| 2019-03-26 | CA3500505_005_005-201903261100 | ND |
| 2022-01-28 | CA3500505_001_001-202201281010 | ND |
| 2022-03-31 | CA3500505_005_005-202203311345 | ND |