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EWG's Tap Water Database — 2019 UPDATE

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Diquat

City of Hollister

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

 

16

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
2014ND60ND
2015N/A00N/A
2016ND50ND
2017ND50ND

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
2014-03-251610-009-1555ND
2014-03-251610-007-1445ND
2014-03-251610-006-1425ND
2014-03-251610-005-1540ND
2014-03-251610-002-1700ND
2014-03-251610-001-1635ND
2016-12-141610-007-1144ND
2016-12-141610-006-1105ND
2016-12-141610-005-0848ND
2016-12-141610-002-1013ND
2016-12-141610-001-0952ND
2017-12-079590-006-0950ND
2017-12-079590-007-1014ND
2017-12-079590-005-1048ND
2017-12-079590-002-1132ND
2017-12-079590-001-1120ND