Know Your Environment. Protect Your Health.

Chloroform

Dorchester, Village of

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.

 

13

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND10ND
2019ND10ND
2020ND30ND
2021ND10ND
20221.26 ppb220.660 ppb - 1.85 ppb
20230.168 ppb51ND - 0.840 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
2018-07-16560158ND
2019-07-15621241ND
2020-05-26667014ND
2020-09-14684285ND
2020-09-28701100ND
2021-07-19745978ND
2022-07-058093020.660 ppb
2022-07-278182751.85 ppb
2023-01-17842469ND
2023-04-24855387ND
2023-05-15855924ND
2023-07-178732600.840 ppb
2023-10-16891653ND