cis-1,2-Dichloroethylene

Bourne Water District

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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	1.31 ppb	1	1	1.31 ppb
2015	0.345 ppb	8	1	ND - 2.76 ppb
2016	1.08 ppb	9	4	ND - 2.77 ppb
2017	1.19 ppb	11	5	ND - 3.56 ppb
2018	0.647 ppb	10	4	ND - 2.03 ppb
2019	0.610 ppb	10	4	ND - 1.83 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	Result
2014-04-09	1.31 ppb
2015-08-10	2.76 ppb
2015-10-13	ND
2015-10-13	ND
2015-10-13	ND
2015-10-13	ND
2015-10-13	ND
2015-10-13	ND
2015-10-13	ND
2016-01-22	2.30 ppb
2016-04-13	2.24 ppb
2016-07-19	2.40 ppb
2016-11-10	ND
2016-11-10	2.77 ppb
2016-11-10	ND
2016-11-10	ND
2016-11-10	ND
2016-11-10	ND
2017-01-25	2.56 ppb
2017-01-25	3.56 ppb
2017-04-25	2.89 ppb
2017-07-26	2.09 ppb
2017-10-03	ND
2017-10-03	ND
2017-10-03	2.01 ppb
2017-10-03	ND
2017-10-03	ND
2017-10-03	ND
2017-10-03	ND
2018-01-10	2.03 ppb
2018-04-09	1.35 ppb
2018-07-12	1.74 ppb
2018-10-22	ND
2018-10-22	ND
2018-10-22	ND
2018-10-22	1.35 ppb
2018-10-22	ND
2018-10-22	ND
2018-10-22	ND
2019-01-23	1.26 ppb
2019-05-08	1.48 ppb
2019-07-26	1.53 ppb
2019-11-19	ND
2019-11-19	ND
2019-11-19	1.83 ppb
2019-11-19	ND
2019-11-19	ND
2019-11-19	ND
2019-11-19	ND