Hexachlorocyclopentadiene

Colorado Springs Utilities

Hexachlorocyclopentadiene was historically used for the manufacture of currently banned pesticides, such as endrin, dieldrin and chlordane. It’s still used for production of flame retardants, resins and plastics.

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
2013	N/A	0	0	N/A
2014	0.0250 ppb	2	1	ND - 0.0500 ppb
2015	0.0190 ppb	3	1	ND - 0.0570 ppb
2016	0.0128 ppb	12	3	ND - 0.0700 ppb
2017	0.0210 ppb	6	2	ND - 0.0740 ppb
2018	ND	7	0	ND
2019	0.00480 ppb	10	1	ND - 0.0480 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 2 ppb

The EWG Health Guideline of 2 ppb for hexachlorocyclopentadiene 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 harm to the stomach and intestines.

EPA Maximum Contaminant
Level (MCL) 50 ppb

The legal limit for hexachlorocyclopentadiene, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.

ppb = parts per billion

All test results

Date	Result
2014-01-08	ND
2014-05-13	0.0500 ppb
2015-05-05	0.0570 ppb
2015-06-25	ND
2015-07-01	ND
2016-04-04	ND
2016-04-04	ND
2016-04-05	ND
2016-05-10	ND
2016-05-25	0.0530 ppb
2016-07-05	ND
2016-07-05	0.0700 ppb
2016-07-05	ND
2016-07-06	ND
2016-07-06	ND
2016-10-03	ND
2016-10-03	0.0300 ppb
2017-01-04	ND
2017-01-04	ND
2017-04-05	0.0740 ppb
2017-06-27	ND
2017-07-05	ND
2017-11-20	0.0520 ppb
2018-01-10	ND
2018-04-04	ND
2018-04-04	ND
2018-07-02	ND
2018-08-01	ND
2018-10-04	ND
2018-11-13	ND
2019-05-08	ND
2019-05-08	ND
2019-05-08	ND
2019-05-08	ND
2019-05-16	0.0480 ppb
2019-10-02	ND
2019-10-02	ND
2019-10-02	ND
2019-10-02	ND
2019-10-02	ND