Diquat
City of Walterboro
Diquat is a herbicide used on potato crops and aquatic weeds.
19
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 | N/A | 0 | 0 | N/A |
| 2015 | ND | 11 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 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 |
|---|---|---|
| 2015-07-29 | AD58785 | ND |
| 2015-07-29 | AD58786 | ND |
| 2015-07-29 | AD58799 | ND |
| 2015-07-29 | AD58800 | ND |
| 2015-07-29 | AD58806 | ND |
| 2015-07-29 | AD58783 | ND |
| 2015-08-05 | AD59199 | ND |
| 2015-08-05 | AD59233 | ND |
| 2015-08-05 | AD59198 | ND |
| 2015-08-05 | AD59196 | ND |
| 2015-08-05 | AD59192 | ND |
| 2019-10-22 | AE39023 | ND |
| 2019-10-22 | AE39024 | ND |
| 2019-10-22 | AE39030 | ND |
| 2019-10-23 | AE39131 | ND |
| 2019-10-23 | AE39151 | ND |
| 2019-10-23 | AE39129 | ND |
| 2019-10-24 | AE39272 | ND |
| 2019-10-24 | AE39276 | ND |