Menu

EWG's Tap Water Database — 2019 UPDATE

Donate

Diquat

Johnson Utilities

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

 

12

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND60ND
2013N/A00N/A
2014N/A00N/A
2015ND40ND
2016ND20ND
2017N/A00N/A

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
2012-01-23201201240163SAND
2012-01-23201201240163SBND
2012-01-23201201240163SCND
2012-07-26201207270233SAND
2012-07-26201207270233SBND
2012-07-26201207270233SCND
2015-03-04201503040395SAND
2015-03-04201503040395SBND
2015-06-17201506170582SAND
2015-06-17201506170582SBND
2016-02-17201602180080SND
2016-10-27201610270264SND