Diquat
City of Wichita Falls
Diquat is a herbicide used on potato crops and aquatic weeds.
8
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 | 2 | 0 | ND |
| 2015 | 0.467 ppb | 3 | 2 | ND - 0.800 ppb |
| 2016 | ND | 1 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 1 | 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 |
|---|---|---|
| 2014-08-14 | AC63813 | ND |
| 2014-11-12 | AC71872 | ND |
| 2015-02-09 | AC79797 | 0.600 ppb |
| 2015-05-11 | AC91460 | 0.800 ppb |
| 2015-09-22 | AD08109 | ND |
| 2016-02-01 | AD21628 | ND |
| 2018-11-28 | AE47255 | ND |
| 2019-05-14 | AE66328 | ND |