Know Your Environment. Protect Your Health.

Chloroform

Town of Sunset Water System

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.

 

16

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND40ND
2019ND40ND
20200.320 ppb21ND - 0.640 ppb
20210.485 ppb21ND - 0.970 ppb
20220.275 ppb21ND - 0.550 ppb
20230.400 ppb21ND - 0.800 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
2018-05-1835393236001ND
2018-05-1835393236002ND
2018-05-1835393236001ND
2018-05-1835393236002ND
2019-05-2335470947001ND
2019-05-2335470947002ND
2019-05-2335470947001ND
2019-05-2335470947002ND
2020-05-0835548861001ND
2020-05-08355488610020.640 ppb
2021-05-0635631397001ND
2021-05-06356313970020.970 ppb
2022-05-1735719216001ND
2022-05-17357192160020.550 ppb
2023-05-0535797737001ND
2023-05-05357977370020.800 ppb