Know Your Environment. Protect Your Health.

Diquat

Norwalk First Taxing District

Diquat is a herbicide used on potato crops and aquatic weeds.

 

5

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018N/A00N/A
2019ND20ND
2020N/A00N/A
2021ND10ND
2022ND10ND
2023ND10ND

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
2019-09-12214-15433SOC5ND
2019-11-07214-15440SOC5ND
2021-03-11214-17905SOC5ND
2022-04-21214-19954SOC5ND
2023-04-13214-21980SOC5ND