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EWG's Tap Water Database — 2021 UPDATE

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cis-1,2-Dichloroethylene

San Francisco Regional Water System

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.

 

20

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND20ND
2016ND30ND
2017ND30ND
2018ND30ND
2019ND70ND

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
2014-06-179553-016-0904ND
2014-06-179553-001-1130ND
2015-05-279553-001-1235ND
2015-06-189553-015-0915ND
2016-06-149553-001-1105ND
2016-06-149553-015-1231ND
2016-06-219553-016-1055ND
2017-06-199553-015-1100ND
2017-06-199553-016-0953ND
2017-06-199553-001-1025ND
2018-06-189553-016-1100ND
2018-06-189553-001-1032ND
2018-06-289590-015-0950ND
2019-06-179553-001-1012ND
2019-06-179553-015-1119ND
2019-06-249590-034-1035ND
2019-06-249590-035-1137ND
2019-06-269590-031-1430ND
2019-06-269590-032-0925ND
2019-06-269590-033-1125ND