Know Your Environment. Protect Your Health.

Chloroform

City of Tumwater

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.

 

31

Samples

0

Samples exceeding legal limit (MCL)

13

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.331 ppb137ND - 0.800 ppb
20190.200 ppb72ND - 0.800 ppb
2020N/A00N/A
20210.550 ppb21ND - 1.10 ppb
20220.214 ppb71ND - 1.50 ppb
20231.06 ppb220.720 ppb - 1.40 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
2018-02-270.600 ppb
2018-02-27ND
2018-02-270.800 ppb
2018-02-270.600 ppb
2018-05-300.500 ppb
2018-05-30ND
2018-05-30ND
2018-05-300.500 ppb
2018-08-290.600 ppb
2018-08-29ND
2018-08-29ND
2018-08-290.700 ppb
2018-10-25ND
2019-04-24ND
2019-04-240.800 ppb
2019-04-240.600 ppb
2019-04-24ND
2019-07-31ND
2019-08-28ND
2019-08-28ND
2021-05-044112923ND
2021-05-0441129251.10 ppb
2022-08-254359875ND
2022-08-254359872ND
2022-08-254359873ND
2022-08-254359874ND
2022-08-254359876ND
2022-08-254359136ND
2022-08-2543591411.50 ppb
2023-09-1345257770.720 ppb
2023-09-1345257781.40 ppb