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EWG's Tap Water Database — 2021 UPDATE

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Diquat

Colchester Commons

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

 

13

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND40ND
2015ND10ND
2016ND30ND
2017ND10ND
2018ND10ND
2019ND30ND

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
2014-02-19BG10471SOC5ND
2014-04-18BG34477SOC5ND
2014-07-29BG83661SOC5ND
2014-10-16BH28216SOC5ND
2015-04-24BJ07685SOC5ND
2016-03-24BK87904SOC5ND
2016-03-24BK87905SOC5ND
2016-03-24BK87906SOC5ND
2017-10-10BZ18334SOC5ND
2018-04-27CA37957SOC5ND
2019-10-21CE44558ND
2019-10-21CE44559ND
2019-10-21CE44556ND