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EWG's Tap Water Database — 2021 UPDATE

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Diquat

North Kona

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

MORE ABOUT THIS CONTAMINANT

 

39

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
2016ND180ND
2017N/A00N/A
2018ND140ND
2019ND70ND

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
2016-03-15ND
2016-03-15ND
2016-03-15ND
2016-03-21ND
2016-03-21ND
2016-03-21ND
2016-03-21ND
2016-03-21ND
2016-03-21ND
2016-05-24ND
2016-05-24ND
2016-05-24ND
2016-05-24ND
2016-05-24ND
2016-05-24ND
2016-05-24ND
2016-05-25ND
2016-05-25ND
2018-05-22201805170773ND
2018-05-22201805170778ND
2018-05-23201805170774ND
2018-05-23201805290216ND
2018-05-23201805290227ND
2018-05-23201805290225ND
2018-07-08201805230559ND
2018-10-15201810170192ND
2018-10-22201810240383ND
2018-10-22201810240336ND
2018-10-29201810310535ND
2018-10-29201810310336ND
2018-10-29201810310409ND
2018-10-29201810310350ND
2019-01-07201901090296ND
2019-01-07201901090308ND
2019-04-29201905010517ND
2019-07-15201907170652ND
2019-07-15201907170514ND
2019-09-09201909100461ND
2019-10-09201910110607ND