Know Your Environment. Protect Your Health.

Chloroform

Harris County Municipal Utility District 189

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.

 

17

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND30ND
2019ND30ND
2020ND30ND
2021ND20ND
20220.800 ppb21ND - 1.60 ppb
20230.675 ppb41ND - 2.70 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
2018-05-17AE26817ND
2018-05-17AE26821ND
2018-05-17AE26723ND
2019-07-08AE73372ND
2019-07-08AE73468ND
2019-07-08AE73470ND
2020-06-23AF16548ND
2020-06-23AF16542ND
2020-06-23AF16510ND
2021-06-10AF57433ND
2021-10-14AF73563ND
2022-04-05AF92017ND
2022-07-21AG057471.60 ppb
2023-07-20AG49574ND
2023-07-20AG496132.70 ppb
2023-10-12AG59736ND
2023-11-02AG62177ND