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EWG's Tap Water Database — 2021 UPDATE

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Diquat

Harvest-Monrovia Water System

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
2014N/A00N/A
2015N/A00N/A
2016ND60ND
2017N/A00N/A
2018N/A00N/A
2019ND60ND

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
2016-06-08AB12276ND
2016-09-07AB14883ND
2016-09-07AB14884ND
2016-09-07AB14882ND
2016-12-08AB16887ND
2016-12-08AB16886ND
2019-03-05AB33091ND
2019-03-05AB33089ND
2019-03-05AB33088ND
2019-09-03AB38175ND
2019-09-03AB38174ND
2019-09-03AB38173ND