Know Your Environment. Protect Your Health.

Diquat

Regional Water Authority

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

 

54

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018N/A00N/A
2019ND220ND
2020N/A00N/A
2021N/A00N/A
2022ND320ND
2023N/A00N/A

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
2019-05-08SOC 200531300ND
2019-05-28SOC 200533720ND
2019-05-28SOC 200533719ND
2019-05-28SOC 200533803ND
2019-05-28SOC 200533804ND
2019-05-28SOC 200533660ND
2019-05-28SOC 200533659ND
2019-05-29SOC 200533881ND
2019-05-29SOC 200533880ND
2019-05-29SOC 200533867ND
2019-05-29SOC 200533868ND
2019-08-26SOC 200546197ND
2019-08-26SOC 200546198ND
2019-08-26SOC 200546200ND
2019-08-27SOC 200546267ND
2019-08-27SOC 200546303ND
2019-08-27SOC 200546302ND
2019-08-27SOC 200546268ND
2019-08-28SOC 200546738ND
2019-08-28SOC 200546737ND
2019-08-28SOC 200546736ND
2019-08-28SOC 200546553ND
2022-07-11S300210822 300210826ND
2022-07-11S300210156 300210160ND
2022-07-11S300210164 300210168ND
2022-07-11S300210651 300210655ND
2022-07-11S300210659 300210663ND
2022-07-12S300211086 300211090ND
2022-07-12S300211076 300211080ND
2022-07-12S300211068 300211072ND
2022-07-13S300212413 300212417ND
2022-07-13S300212421 300212425ND
2022-07-14S300212957 300212961ND
2022-10-17S300258850 300258854ND
2022-10-17300258850 300258854BND
2022-10-17300258858 300258862BND
2022-10-17S300258858 300258862ND
2022-10-18S300259358 300259362ND
2022-10-18S300258921 300258925ND
2022-10-18300258921 300258925BND
2022-10-18300259358 300259362BND
2022-10-18S300259350 300259354ND
2022-10-18300259350 300259354BND
2022-10-18300258913 300258917BND
2022-10-18S300258913 300258917ND
2022-10-19S300259930 300259936ND
2022-10-19300259930 300259936BND
2022-10-19300259940 300259944BND
2022-10-19S300259940 300259944ND
2022-10-19S300260499 300260503ND
2022-10-19300260499 300260503BND
2022-10-19300260507 300260511BND
2022-10-19S300260507 300260511ND
2022-12-06S300281400 300281404ND