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EWG's Tap Water Database — 2019 UPDATE

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Diquat

Freeport

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
2012ND40ND
2013N/A00N/A
2014ND30ND
2015ND50ND
2016N/A00N/A
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
2012-01-231201B48-003AND
2012-01-231201B48-006AND
2012-04-251204C70-003AND
2012-04-251204C70-006AND
2014-05-191405A33-001AND
2014-07-151407A33-003AND
2014-10-291410G35-003AND
2015-01-201501B51-002AND
2015-01-201501B51-005AND
2015-01-201501B51-007AND
2015-05-261505K11-003AND
2015-05-261505K11-006AND