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EWG's Tap Water Database — 2019 UPDATE

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Diquat

Centennial Water and Sanitation District

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

 

27

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND50ND
2013ND40ND
2014ND20ND
2015ND40ND
2016ND60ND
2017ND60ND

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 Result
2012-03-19ND
2012-08-22ND
2012-08-23ND
2012-10-16ND
2012-10-31ND
2013-03-19ND
2013-03-19ND
2013-06-12ND
2013-08-27ND
2014-07-23ND
2014-07-29ND
2015-05-20ND
2015-07-27ND
2015-08-12ND
2015-08-12ND
2016-05-17ND
2016-07-27ND
2016-07-27ND
2016-08-17ND
2016-10-10ND
2016-10-10ND
2017-01-25ND
2017-01-25ND
2017-06-14ND
2017-08-15ND
2017-08-17ND
2017-08-17ND