Know Your Environment. Protect Your Health.

Chloroform

Arrowhead Beach Co-op Water Association

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.

 

19

Samples

0

Samples exceeding legal limit (MCL)

11

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.475 ppb43ND - 0.800 ppb
20190.300 ppb21ND - 0.600 ppb
2020N/A00N/A
20210.300 ppb31ND - 0.900 ppb
20220.220 ppb51ND - 1.10 ppb
20230.820 ppb550.500 ppb - 1.10 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
2018-03-310.600 ppb
2018-05-220.800 ppb
2018-08-140.500 ppb
2018-11-14ND
2019-01-29ND
2019-04-030.600 ppb
2021-05-2741202700.900 ppb
2021-08-204163692ND
2021-11-104210579ND
2022-03-234267559ND
2022-06-294307832ND
2022-07-224325349ND
2022-09-284357000ND
2022-10-3143700111.10 ppb
2023-03-2744372731.10 ppb
2023-06-2744833710.900 ppb
2023-08-2345127350.600 ppb
2023-09-2745325650.500 ppb
2023-11-2745617771.000 ppb