Know Your Environment. Protect Your Health.

Chloroform

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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.

 

18

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND40ND
20190.263 ppb31ND - 0.790 ppb
2020N/A00N/A
2021ND30ND
20220.600 ppb330.600 ppb
20230.148 ppb52ND - 0.380 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
2018-04-10ND
2018-07-25ND
2018-08-08ND
2018-10-31ND
2019-04-08ND
2019-06-11ND
2019-08-050.790 ppb
2021-03-294100649ND
2021-06-024164639ND
2021-08-124163763ND
2022-03-0342546240.600 ppb
2022-03-0342546240.600 ppb
2022-03-0342546240.600 ppb
2023-04-114478121ND
2023-09-204524656ND
2023-09-2045247420.360 ppb
2023-09-2045247430.380 ppb
2023-10-244539329ND