Know Your Environment. Protect Your Health.

Chloroform

City of Vancouver

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.

 

60

Samples

0

Samples exceeding legal limit (MCL)

42

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.74 ppb10100.710 ppb - 3.94 ppb
20190.739 ppb188ND - 3.50 ppb
2020N/A00N/A
20210.895 ppb148ND - 2.60 ppb
20221.45 ppb108ND - 3.00 ppb
20231.89 ppb880.950 ppb - 3.50 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.4 ppb

The EWG Health Guideline of 0.4 ppb for chloroform was based on the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to fetal growth and development.

ppb = parts per billion

All test results

Date Lab ID Result
2018-02-281.03 ppb
2018-02-281.83 ppb
2018-06-130.720 ppb
2018-06-130.710 ppb
2018-06-130.760 ppb
2018-06-132.91 ppb
2018-09-123.94 ppb
2018-09-120.740 ppb
2018-12-123.18 ppb
2018-12-121.62 ppb
2019-03-132.04 ppb
2019-03-131.18 ppb
2019-05-300.630 ppb
2019-05-30ND
2019-06-19ND
2019-06-191.40 ppb
2019-09-183.50 ppb
2019-09-180.980 ppb
2019-11-132.80 ppb
2019-11-130.770 ppb
2019-12-10ND
2019-12-10ND
2019-12-10ND
2019-12-10ND
2019-12-10ND
2019-12-10ND
2019-12-10ND
2019-12-10ND
2021-03-2440943322.30 ppb
2021-03-2440943331.50 ppb
2021-03-304096450ND
2021-03-304096453ND
2021-03-304096451ND
2021-03-304096452ND
2021-05-1841187622.00 ppb
2021-05-184118752ND
2021-06-2841362710.970 ppb
2021-06-2841362702.60 ppb
2021-09-2341834870.960 ppb
2021-09-234183488ND
2021-11-1742132101.50 ppb
2021-11-1742132110.700 ppb
2022-03-1642580312.70 ppb
2022-03-1642580320.600 ppb
2022-03-244266311ND
2022-03-244266312ND
2022-06-2343039063.00 ppb
2022-06-2343039071.50 ppb
2022-09-1443590632.00 ppb
2022-09-1443590660.820 ppb
2022-11-1643829132.60 ppb
2022-11-1643829151.30 ppb
2023-02-1544164041.90 ppb
2023-02-1544164051.000 ppb
2023-05-2444659203.50 ppb
2023-05-2444659210.950 ppb
2023-08-1645055751.10 ppb
2023-08-1645055742.70 ppb
2023-11-1545501812.70 ppb
2023-11-1545501841.30 ppb