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EWG's Tap Water Database — 2019 UPDATE

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Diquat

Cary

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

 

32

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND160ND
2013N/A00N/A
2014N/A00N/A
2015ND140ND
2016ND20ND
2017N/A00N/A

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
2012-07-242073552-01ND
2012-07-242073552-02ND
2012-07-242073552-03ND
2012-07-242073552-08ND
2012-07-242073552-04ND
2012-07-242073552-05ND
2012-07-242073552-07ND
2012-07-242073552-06ND
2012-11-282113509-01ND
2012-11-282113509-08ND
2012-11-282113509-07ND
2012-11-282113509-06ND
2012-11-282113509-05ND
2012-11-282113509-04ND
2012-11-282113509-03ND
2012-11-282113509-02ND
2015-09-015090819-01ND
2015-09-015090817-04ND
2015-09-015090817-03ND
2015-09-015090817-02ND
2015-09-015090817-01ND
2015-09-015090819-04ND
2015-09-015090819-03ND
2015-09-015090819-02ND
2015-11-195113111-01ND
2015-11-195113111-02ND
2015-11-195113106-02ND
2015-11-195113102-02ND
2015-11-195113106-01ND
2015-11-235113717-02ND
2016-01-066011004-02ND
2016-01-076011004-01ND