cis-1,2-Dichloroethylene

Red Hill Water Authority

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.

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Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	6	ND
2015	ND	5	ND
2016	ND	3	ND
2017	ND	9	ND
2018	ND	5	ND
2019	ND	6	ND

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
2014-03-12	140010197	ND
2014-03-12	140010198	ND
2014-03-12	140010199	ND
2014-05-14	140020004	ND
2014-07-23	140032263	ND
2014-11-05	140050162	ND
2015-02-18	12402522	ND
2015-03-04	12516320	ND
2015-04-22	12634000	ND
2015-07-29	13013719	ND
2015-11-18	13515020	ND
2016-02-03	13871059	ND
2016-02-03	13871080	ND
2016-11-10	15227177	ND
2017-02-08	15656498	ND
2017-02-08	15656499	ND
2017-02-08	15656500	ND
2017-03-29	15796768	ND
2017-05-31	16095724	ND
2017-07-26	16414764	ND
2017-09-26	16727965	ND
2017-09-26	16727966	ND
2017-10-18	16881221	ND
2018-02-07	8001980-01	ND
2018-04-25	8008151-01	ND
2018-07-17	8017901-01	ND
2018-08-07	8021854-01	ND
2018-10-22	8028636-01	ND
2019-02-06	9002686-01	ND
2019-05-07	9009679-01	ND
2019-06-25	9022004-01	ND
2019-08-21	9025620-01	ND
2019-09-24	9021809-01	ND
2019-12-16	9033958-01	ND