Chloroform

East Cherry Creek Valley Water and Sanitation District

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.

In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

120

Samples

Samples exceeding legal limit (MCL)

109

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	N/A	0	0	N/A
2015	8.12 ppb	24	22	ND - 25.0 ppb
2016	2.94 ppb	32	27	ND - 8.90 ppb
2017	6.88 ppb	32	31	ND - 23.2 ppb
2018	4.01 ppb	16	15	ND - 6.70 ppb
2019	14.5 ppb	16	14	ND - 31.7 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

ppb = parts per billion

All test results

Date	Result
2015-05-07	3.40 ppb
2015-05-07	2.90 ppb
2015-05-07	3.20 ppb
2015-05-07	3.30 ppb
2015-05-07	2.60 ppb
2015-05-07	3.00 ppb
2015-05-07	2.00 ppb
2015-05-07	2.10 ppb
2015-08-12	4.90 ppb
2015-08-12	ND
2015-08-12	5.20 ppb
2015-08-12	6.00 ppb
2015-08-12	4.10 ppb
2015-08-12	4.40 ppb
2015-08-12	3.80 ppb
2015-08-12	4.00 ppb
2015-11-23	22.9 ppb
2015-11-23	17.4 ppb
2015-11-23	19.3 ppb
2015-11-23	25.0 ppb
2015-11-23	19.2 ppb
2015-11-23	ND
2015-11-23	18.1 ppb
2015-11-23	18.0 ppb
2016-02-12	5.30 ppb
2016-02-12	ND
2016-02-12	ND
2016-02-12	5.50 ppb
2016-02-12	3.50 ppb
2016-02-12	1.000 ppb
2016-02-12	2.20 ppb
2016-02-12	4.20 ppb
2016-05-19	4.20 ppb
2016-05-19	ND
2016-05-19	4.00 ppb
2016-05-19	4.50 ppb
2016-05-19	3.60 ppb
2016-05-19	1.40 ppb
2016-05-19	3.40 ppb
2016-05-19	3.40 ppb
2016-08-19	2.10 ppb
2016-08-19	ND
2016-08-19	ND
2016-08-19	3.00 ppb
2016-08-19	2.50 ppb
2016-08-19	1.40 ppb
2016-08-19	1.40 ppb
2016-08-19	2.10 ppb
2016-11-03	8.90 ppb
2016-11-03	4.70 ppb
2016-11-03	4.20 ppb
2016-11-03	5.90 ppb
2016-11-03	4.30 ppb
2016-11-03	1.60 ppb
2016-11-03	3.10 ppb
2016-11-03	2.70 ppb
2017-02-09	7.60 ppb
2017-02-09	6.60 ppb
2017-02-09	7.40 ppb
2017-02-09	8.80 ppb
2017-02-09	7.60 ppb
2017-02-09	0.900 ppb
2017-02-09	7.10 ppb
2017-02-09	6.40 ppb
2017-05-17	5.00 ppb
2017-05-17	0.800 ppb
2017-05-17	ND
2017-05-17	4.80 ppb
2017-05-17	3.60 ppb
2017-05-17	1.000 ppb
2017-05-17	2.90 ppb
2017-05-17	3.50 ppb
2017-08-10	2.80 ppb
2017-08-10	2.60 ppb
2017-08-10	3.30 ppb
2017-08-10	4.30 ppb
2017-08-10	2.80 ppb
2017-08-10	2.80 ppb
2017-08-10	2.30 ppb
2017-08-10	2.30 ppb
2017-11-09	23.2 ppb
2017-11-09	18.6 ppb
2017-11-09	16.6 ppb
2017-11-09	17.1 ppb
2017-11-09	15.9 ppb
2017-11-09	14.8 ppb
2017-11-09	13.6 ppb
2017-11-10	3.00 ppb
2018-02-07	6.50 ppb
2018-02-07	3.80 ppb
2018-02-07	3.60 ppb
2018-02-07	6.70 ppb
2018-02-07	2.70 ppb
2018-02-07	3.60 ppb
2018-02-07	4.30 ppb
2018-02-07	3.80 ppb
2018-05-17	5.10 ppb
2018-05-17	ND
2018-05-17	4.50 ppb
2018-05-17	6.10 ppb
2018-05-17	3.00 ppb
2018-05-17	4.30 ppb
2018-05-17	2.80 ppb
2018-05-17	3.30 ppb
2019-08-19	4.70 ppb
2019-08-19	5.40 ppb
2019-08-19	6.20 ppb
2019-08-19	5.40 ppb
2019-08-19	4.50 ppb
2019-08-19	ND
2019-08-19	ND
2019-08-19	4.30 ppb
2019-11-13	31.7 ppb
2019-11-13	21.7 ppb
2019-11-13	27.1 ppb
2019-11-13	29.4 ppb
2019-11-13	24.2 ppb
2019-11-13	22.0 ppb
2019-11-13	26.2 ppb
2019-11-13	19.4 ppb