Chloroform

Ramsey Water Department

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

216

Samples

Samples exceeding legal limit (MCL)

101

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	4.05 ppb	40	16	ND - 24.6 ppb
2015	7.54 ppb	26	18	ND - 25.5 ppb
2016	4.60 ppb	38	16	ND - 28.9 ppb
2017	5.00 ppb	41	17	ND - 27.4 ppb
2018	6.48 ppb	35	16	ND - 28.7 ppb
2019	9.58 ppb	36	18	ND - 48.8 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	Lab ID	Result
2014-01-07	24919-11	ND
2014-01-07	24919-9	ND
2014-02-12	25456-21	2.52 ppb
2014-02-12	25456-20	2.63 ppb
2014-02-12	25456-19	2.58 ppb
2014-02-12	25456-18	2.63 ppb
2014-03-04	25674-11	ND
2014-04-09	26199-11	ND
2014-04-09	26199-9	ND
2014-05-12	26666-14	7.98 ppb
2014-05-12	26666-13	15.7 ppb
2014-05-12	26666-12	14.1 ppb
2014-05-12	26666-11	3.72 ppb
2014-05-12	26666-22	ND
2014-05-12	26666-20	ND
2014-05-12	26666-17	ND
2014-05-19	26781-10	ND
2014-05-19	26781-13	ND
2014-05-19	26781-11	ND
2014-05-19	26781-12	ND
2014-06-18	27338-11	ND
2014-06-18	27338-9	ND
2014-06-25	27435-19	ND
2014-07-17	27886-11	ND
2014-07-17	27886-9	ND
2014-08-11	28209-4	16.9 ppb
2014-08-11	28209-3	24.6 ppb
2014-08-11	28209-2	24.5 ppb
2014-08-11	28209-1	15.2 ppb
2014-09-17	28891-11	ND
2014-09-17	28891-9	ND
2014-10-06	29268-11	ND
2014-10-06	29268-9	ND
2014-11-10	29791-12	4.74 ppb
2014-11-10	29791-11	11.9 ppb
2014-11-10	29791-10	9.62 ppb
2014-11-10	29791-9	2.59 ppb
2014-11-10	29791-6	ND
2014-11-10	29791-8	ND
2014-11-10	29791-3	ND
2015-01-13	30764-9	ND
2015-02-11	31208-4	2.71 ppb
2015-02-11	31208-3	1.93 ppb
2015-02-11	31208-2	2.21 ppb
2015-02-11	31208-1	1.20 ppb
2015-04-13	DWS166-9	ND
2015-04-20	DWS247-4	2.08 ppb
2015-04-20	DWS247-2	2.02 ppb
2015-05-11	DWS510-4	8.37 ppb
2015-05-11	DWS510-3	13.6 ppb
2015-05-11	DWS510-2	13.0 ppb
2015-05-11	DWS510-1	5.49 ppb
2015-07-14	DWSC34-11	ND
2015-07-14	DWSC34-9	ND
2015-08-11	DWSC183-4	23.1 ppb
2015-08-11	DWSC183-3	25.3 ppb
2015-08-11	DWSC183-2	25.5 ppb
2015-08-11	DWSC183-1	11.6 ppb
2015-10-08	DWSC573-3	ND
2015-10-08	DWSC573-1	ND
2015-11-16	DWSC774-4	13.9 ppb
2015-11-16	DWSC774-3	15.0 ppb
2015-11-16	DWSC774-2	15.0 ppb
2015-11-16	DWSC774-1	13.9 ppb
2015-11-16	DWSC777-3	ND
2015-12-15	DWSC921-9	ND
2016-01-06	DWSC986-9	ND
2016-02-11	DWSC1128-4	4.52 ppb
2016-02-11	DWSC1128-3	5.04 ppb
2016-02-11	DWSC1128-2	4.82 ppb
2016-02-11	DWSC1128-1	4.43 ppb
2016-02-25	DWSC1176-8	ND
2016-03-15	DWSC1282-9	ND
2016-04-12	DWSC1408-16	ND
2016-05-16	DWSC1545-4	6.40 ppb
2016-05-16	DWSC1545-3	10.1 ppb
2016-05-16	DWSC1545-2	9.95 ppb
2016-05-16	DWSC1545-1	3.79 ppb
2016-05-17	DWSC1548-22	ND
2016-05-17	DWSC1548-19	ND
2016-06-07	DWSC1635-3	ND
2016-06-07	DWSC1635-1	ND
2016-07-13	DWSC1811-9	ND
2016-07-14	DWSC1824-1	ND
2016-08-15	DWSC1958-4	19.0 ppb
2016-08-15	DWSC1958-3	28.9 ppb
2016-08-15	DWSC1958-2	28.6 ppb
2016-08-15	DWSC1958-1	24.2 ppb
2016-08-23	DWSC2000-10	ND
2016-08-23	DWSC1999-1	ND
2016-09-07	DWSC2050-8	ND
2016-09-07	DWSC2050-6	ND
2016-09-07	DWSC2050-3	ND
2016-10-05	DWSC2196-3	ND
2016-10-05	DWSC2196-1	ND
2016-11-14	DWSC2363-15	ND
2016-11-14	DWSC2363-14	ND
2016-11-14	DWSC2363-12	ND
2016-11-15	DWSC2370-12	5.43 ppb
2016-11-15	DWSC2370-11	9.22 ppb
2016-11-15	DWSC2370-10	8.34 ppb
2016-11-15	DWSC2370-9	1.87 ppb
2016-12-05	DWSC2445-11	ND
2016-12-05	DWSC2445-9	ND
2017-01-09	DWSC2587-9	ND
2017-02-13	DWSC2694-4	4.99 ppb
2017-02-13	DWSC2694-3	5.05 ppb
2017-02-13	DWSC2694-2	4.63 ppb
2017-02-13	DWSC2694-1	1.32 ppb
2017-02-13	DWSC2693-3	ND
2017-04-03	DWSC2911-17	ND
2017-05-03	DWSC3048-6	ND
2017-05-03	DWSC3048-3	ND
2017-05-10	DWSC3102-4	12.1 ppb
2017-05-10	DWSC3102-3	12.8 ppb
2017-05-10	DWSC3102-2	4.42 ppb
2017-05-10	DWSC3102-1	3.55 ppb
2017-05-24	DWSC3190-2	ND
2017-05-24	DWSC3190-3	ND
2017-05-24	DWSC3190-4	0.570 ppb
2017-05-24	DWSC3190-5	ND
2017-05-24	DWSC3190-1	ND
2017-06-12	DWSC3284-3	ND
2017-06-12	DWSC3284-1	ND
2017-07-10	DWSC3454-2	ND
2017-07-10	DWSC3454-1	ND
2017-08-14	DWSC3676-4	20.2 ppb
2017-08-14	DWSC3676-3	27.4 ppb
2017-08-14	DWSC3676-2	19.8 ppb
2017-08-14	DWSC3676-1	16.6 ppb
2017-08-14	DWSC3675-6	ND
2017-08-14	DWSC3675-4	ND
2017-08-14	DWSC3675-2	ND
2017-09-05	DWSC3824-2	ND
2017-09-05	DWSC3824-1	ND
2017-10-03	DWSC4026-3	ND
2017-10-03	DWSC4026-1	ND
2017-11-06	DWSC4205-7	ND
2017-11-06	DWSC4205-5	ND
2017-11-06	DWSC4205-2	ND
2017-11-13	DWSC4257-4	15.1 ppb
2017-11-13	DWSC4257-3	20.6 ppb
2017-11-13	DWSC4257-2	19.2 ppb
2017-11-13	DWSC4257-1	16.7 ppb
2017-12-05	DWSC4370-9	ND
2018-01-22	DWSC4635-9	ND
2018-02-06	DWSC4707-1	ND
2018-02-12	DWSC4738-4	2.86 ppb
2018-02-12	DWSC4738-3	2.68 ppb
2018-02-12	DWSC4738-2	2.41 ppb
2018-02-12	DWSC4738-1	4.67 ppb
2018-03-06	DWSC4871-1	ND
2018-04-09	DWSC5063-9	ND
2018-05-14	DWSC5300-4	10.6 ppb
2018-05-14	DWSC5300-3	11.4 ppb
2018-05-14	DWSC5300-2	7.21 ppb
2018-05-14	DWSC5300-1	6.67 ppb
2018-05-21	DWSC5356-8	ND
2018-05-21	DWSC5356-6	ND
2018-05-21	DWSC5356-3	ND
2018-06-04	DWSC5419-2	ND
2018-06-04	DWSC5419-1	ND
2018-07-09	18070948-02	ND
2018-07-09	18070948-01	ND
2018-08-13	18081407-04	22.2 ppb
2018-08-13	18081407-03	21.1 ppb
2018-08-13	18081407-02	27.1 ppb
2018-08-13	18081407-01	20.9 ppb
2018-08-13	18081408-08	ND
2018-08-13	18081408-06	ND
2018-08-13	18081408-03	ND
2018-09-04	18090406-03	ND
2018-09-04	18090406-01	ND
2018-10-02	18100309-09	ND
2018-11-13	18111406-04	28.7 ppb
2018-11-13	18111406-03	26.5 ppb
2018-11-13	18111406-02	26.1 ppb
2018-11-13	18111406-01	5.74 ppb
2018-11-13	18111405-03	ND
2018-12-03	18120405-09	ND
2019-01-08	19010901-01	ND
2019-02-11	19021404-04	13.0 ppb
2019-02-11	19021404-03	13.0 ppb
2019-02-11	19021404-02	11.4 ppb
2019-02-11	19021404-01	6.78 ppb
2019-02-13	19021402-01	ND
2019-03-05	19030605-01	ND
2019-04-02	19040212-01	ND
2019-05-13	3033895004	17.6 ppb
2019-05-13	3033895003	27.7 ppb
2019-05-13	3033895002	29.7 ppb
2019-05-13	3033895001	8.00 ppb
2019-05-14	19051501-02	ND
2019-06-18	19061804-003	ND
2019-06-18	19061804-007	ND
2019-07-09	19071204-002	ND
2019-07-09	19071204-001	ND
2019-08-06	19080701-008	0.670 ppb
2019-08-06	19080701-006	0.670 ppb
2019-08-06	19080701-003	ND
2019-08-12	19081215-004	38.4 ppb
2019-08-12	19081215-003	48.8 ppb
2019-08-12	19081215-002	44.9 ppb
2019-08-12	19081215-001	34.5 ppb
2019-09-10	19091343-002	ND
2019-09-10	19091343-001	ND
2019-10-08	19101001-002	ND
2019-10-08	19101001-001	ND
2019-10-22	19102302-003	ND
2019-10-22	19102302-001	ND
2019-11-05	19110604-001	ND
2019-11-12	19111216-004	15.4 ppb
2019-11-12	19111216-003	15.7 ppb
2019-11-12	19111216-002	14.1 ppb
2019-11-12	19111216-001	4.73 ppb
2019-12-05	19120608-001	ND