Know Your Environment. Protect Your Health.

Chloroform

Stanley Lake Municipal Utility District

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.

 

29

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.367 ppb31ND - 1.10 ppb
2019ND30ND
20200.200 ppb51ND - 1.000 ppb
2021ND50ND
20220.900 ppb74ND - 2.00 ppb
2023ND60ND

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
2018-02-20AE144591.10 ppb
2018-02-20AE14433ND
2018-05-09AE25733ND
2019-03-04AE56885ND
2019-03-04AE56889ND
2019-09-13AE83541ND
2020-08-11AF228281.000 ppb
2020-08-11AF22868ND
2020-08-11AF22870ND
2020-08-11AF22872ND
2020-11-20AF35494ND
2021-01-14AF39546ND
2021-01-14AF39560ND
2021-01-14AF39570ND
2021-04-14AF50172ND
2021-06-11AF57717ND
2022-08-04AG07815ND
2022-08-04AG078831.40 ppb
2022-08-04AG07885ND
2022-08-04AG078892.00 ppb
2022-08-04AG078911.50 ppb
2022-10-18AG173991.40 ppb
2022-10-18AG17401ND
2023-01-25AG26238ND
2023-01-25AG26240ND
2023-01-25AG26244ND
2023-01-25AG26258ND
2023-04-10AG36106ND
2023-06-16AG44834ND