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EWG's Tap Water Database — 2019 UPDATE

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Diquat

Water District 1 of Johnson County

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

 

19

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND30ND
2013ND40ND
2014ND30ND
2015ND30ND
2016ND30ND
2017ND30ND

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
2012-05-22MAY2012-SOC-TP2ND
2012-05-22MAY2012-SOC-TP3ND
2012-05-30MAY2012-SOC-TP1ND
2013-05-01MAY2013-OC-TP1ND
2013-05-01MAY2013-OC-TP2ND
2013-05-01MAY2013-OC-TP3ND
2013-07-08JUL2013-OC-TP1ND
2014-05-07MAY2014-OC-TP3ND
2014-05-07MAY2014-OC-TP2ND
2014-05-07MAY2014-OC-TP1ND
2015-05-19MAY2015-SOC-TP1ND
2015-05-19MAY2015-SOC-TP2ND
2015-05-19MAY2015-SOC-TP3ND
2016-05-17MAY2016--TP3ND
2016-05-17MAY2016--TP2ND
2016-06-20JUN2016--TP1ND
2017-05-16MAY2017--TP2 EURND
2017-05-16MAY2017--TP3 EURND
2017-07-12JUL2017--TP1 EURND