Know Your Environment. Protect Your Health.

Diquat

City of Lewiston

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

 

23

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND40ND
2019ND40ND
2020ND60ND
2021ND50ND
2022ND30ND
2023ND10ND

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
2018-02-21S180221045-001ND
2018-02-22S180223004-001ND
2018-12-13S181213011-002ND
2018-12-13S181213011-001ND
2019-01-24S190124017-001ND
2019-04-23S190423067-001ND
2019-04-23S190423067-002ND
2019-08-14S190814080-001ND
2020-02-19S200219035-001ND
2020-07-28SMAG0811-08ND
2020-07-28SMAG0811-07ND
2020-07-28SMAG0811-05ND
2020-07-28SMAG0811-03ND
2020-07-28SMAG0811-01ND
2021-06-29SMBF0852-03ND
2021-06-29SMBF0852-01ND
2021-06-29SMBF0852-07ND
2021-06-29SMBF0852-06ND
2021-06-29SMBF0852-04ND
2022-06-28SMCF0954-01ND
2022-09-21SMCI0682-01ND
2022-11-21SMCK0693-01ND
2023-01-18SMDA0450-01ND