Know Your Environment. Protect Your Health.

Chloroform

Harris County Municipal Utility District 321

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.

 

24

Samples

0

Samples exceeding legal limit (MCL)

7

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.90 ppb43ND - 7.60 ppb
20193.83 ppb441.30 ppb - 5.80 ppb
2020ND40ND
2021ND40ND
2022ND40ND
2023ND40ND

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
2018-01-11AE089111.000 ppb
2018-04-04AE21172ND
2018-07-12AE330973.00 ppb
2018-10-09AE429267.60 ppb
2019-01-31AE524133.50 ppb
2019-04-18AE629611.30 ppb
2019-09-25AE845975.80 ppb
2019-11-07AE888934.70 ppb
2020-02-13AE98421ND
2020-05-28AF13051ND
2020-09-10AF26996ND
2020-12-15AF37656ND
2021-02-09AF43231ND
2021-05-18AF54346ND
2021-08-19AF67105ND
2021-11-16AF76782ND
2022-02-10AF84248ND
2022-04-21AF94017ND
2022-09-29AG15424ND
2022-10-25AG18300ND
2023-03-14AG32936ND
2023-05-18AG41055ND
2023-07-20AG49572ND
2023-12-05AG65465ND