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EWG's Tap Water Database — 2021 UPDATE

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Diquat

Hemlock Farms (main)

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

 

20

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND100ND
2015N/A00N/A
2016N/A00N/A
2017ND100ND
2018N/A00N/A
2019N/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
2014-04-1514041845-001ND
2014-04-1514041839-001ND
2014-04-1514041858-001ND
2014-04-2814050058-001ND
2014-04-2814050059-001ND
2014-08-1114081392-002ND
2014-08-1114081392-003ND
2014-08-1114081392-001ND
2014-08-1114081392-005ND
2014-08-1114081392-004ND
2017-04-2615961266ND
2017-04-2615961265ND
2017-04-2615961267ND
2017-05-0216119240ND
2017-05-0216119239ND
2017-08-0816590235ND
2017-08-1516590284ND
2017-08-1516590285ND
2017-08-2216590287ND
2017-08-2216590286ND