EWG's Tap Water Database — 2021 UPDATE



Jefferson Water Department

1,2-Dichloroethylene, a neurotoxic solvent, exists in two different forms: trans-1,2-dichloroethylene and cis-1,2-dichloroethylene. A mixture of the two forms is used to manufacture other solvents and chemical products.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20141.29 ppb111.29 ppb
20152.14 ppb112.14 ppb
20161.43 ppb111.43 ppb
20171.31 ppb111.31 ppb
20181.55 ppb221.47 ppb - 1.63 ppb
20190.690 ppb110.690 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 70 ppb

The legal limit for cis-1,2-dichloroethylene, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1980s.

ppb = parts per billion

All test results

Date Lab ID Result
2014-10-1520876001.29 ppb
2015-12-211L51592-012.14 ppb
2016-11-301L60047-011.43 ppb
2017-12-041L70286-011.31 ppb
2018-04-021D80162-011.63 ppb
2018-10-091J80834-011.47 ppb
2019-10-011J90156-020.690 ppb