Diquat

Lihue-Kapaa

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

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	1	ND
2015	N/A	0	N/A
2016	N/A	0	N/A
2017	N/A	0	N/A
2018	ND	35	ND
2019	N/A	0	N/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
2014-03-25	201403280346	ND
2018-05-29	201805310728	ND
2018-05-29	201805310727	ND
2018-06-06	201806090374	ND
2018-06-06	201806090380	ND
2018-06-06	201806090381	ND
2018-06-06	201806090373	ND
2018-06-12	201806140887	ND
2018-06-12	201806141145	ND
2018-06-12	201806141144	ND
2018-06-12	201806140889	ND
2018-06-13	201806150527	ND
2018-06-13	201806150518	ND
2018-06-13	201806150684	ND
2018-06-13	201806150685	ND
2018-06-13	201806150729	ND
2018-06-13	201806150730	ND
2018-07-12	201807000000	ND
2018-07-12	201807130880	ND
2018-11-26	201811280312	ND
2018-11-26	201811280331	ND
2018-11-26	201811280311	ND
2018-11-26	201811280330	ND
2018-11-27	201811290380	ND
2018-11-27	201811290211	ND
2018-11-27	201811290212	ND
2018-11-27	201811290381	ND
2018-11-28	201811300187	ND
2018-11-28	201811300186	ND
2018-12-03	201812050453	ND
2018-12-03	201812050458	ND
2018-12-03	201812050355	ND
2018-12-03	201812050336	ND
2018-12-03	201812050356	ND
2018-12-03	201812050335	ND
2018-12-04	201812060388	ND