Know Your Environment. Protect Your Health.

Chloroform

Marshall

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.750 ppb220.700 ppb - 0.800 ppb
20190.600 ppb220.600 ppb
20200.250 ppb21ND - 0.500 ppb
2021ND20ND
20220.300 ppb21ND - 0.600 ppb
2023ND20ND

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
2018-09-1918I1055-010.700 ppb
2018-09-1918I1055-020.800 ppb
2019-09-1719I0991-010.600 ppb
2019-09-1719I0991-020.600 ppb
2020-09-2220I1316-010.500 ppb
2020-09-2220I1316-02ND
2021-09-2721I1477-01ND
2021-09-2721I1477-02ND
2022-09-2722I2193-010.600 ppb
2022-09-2722I2193-02ND
2023-09-1923I1068-01ND
2023-09-1923I1068-02ND