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EWG's Tap Water Database — 2021 UPDATE

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Diquat

Mountain Water & Sanitation District

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

 

18

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND40ND
2016ND30ND
2017N/A00N/A
2018ND50ND
2019ND40ND

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
2014-01-15ND
2014-02-12ND
2015-03-30ND
2015-05-13ND
2015-05-19ND
2015-06-10ND
2016-05-12ND
2016-06-07ND
2016-08-18ND
2018-05-15ND
2018-05-15ND
2018-05-15ND
2018-05-15ND
2018-08-21ND
2019-04-24ND
2019-05-02ND
2019-11-12ND
2019-11-12ND