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EWG's Tap Water Database — 2021 UPDATE

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Diquat

Chino Basin Desalter Authority - Desalter 2

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

MORE ABOUT THIS CONTAMINANT

 

34

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND60ND
2016N/A00N/A
2017ND30ND
2018ND220ND
2019ND10ND

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
2014-01-223334-008-1010ND
2014-01-223334-001-1055ND
2015-01-223334-002-1035ND
2015-01-223334-005-0945ND
2015-05-203334-007-1045ND
2015-08-123334-007-1200ND
2015-08-133334-008-0900ND
2015-11-053334-008-1005ND
2017-01-183334-001-1110ND
2017-12-223334-016-0945ND
2017-12-223334-015-0830ND
2018-01-103334-010-0900ND
2018-01-103334-009-1145ND
2018-01-103334-008-1030ND
2018-01-173334-001-1045ND
2018-01-173334-007-0920ND
2018-01-173334-005-1145ND
2018-01-173334-002-1150ND
2018-01-173334-004-0910ND
2018-01-173334-003-1050ND
2018-03-283334-016-1000ND
2018-03-283334-015-0905ND
2018-04-103334-007-1040ND
2018-04-103334-010-0945ND
2018-04-103334-009-1155ND
2018-04-103334-008-0830ND
2018-04-113334-003-1030ND
2018-04-113334-002-0845ND
2018-04-113334-004-1130ND
2018-04-113334-005-0845ND
2018-04-113334-001-1030ND
2018-06-223334-015-1030ND
2018-06-223334-016-0850ND
2019-02-123334-001-1030ND