Know Your Environment. Protect Your Health.

Chloroform

El Oso Water Supply Corporation

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.

 

61

Samples

0

Samples exceeding legal limit (MCL)

41

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.750 ppb105ND - 2.10 ppb
20191.44 ppb108ND - 3.00 ppb
20201.34 ppb1210ND - 2.30 ppb
20210.930 ppb107ND - 1.60 ppb
20220.233 ppb92ND - 1.10 ppb
20231.76 ppb109ND - 4.20 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
2018-01-24AE10141ND
2018-01-24AE101401.60 ppb
2018-01-24AE10234ND
2018-01-24AE102001.000 ppb
2018-04-17AE229891.000 ppb
2018-04-17AE229931.80 ppb
2018-07-27AE348432.10 ppb
2018-07-27AE34846ND
2018-10-22AE44086ND
2018-10-22AE44087ND
2019-02-19AE548372.10 ppb
2019-02-19AE548381.000 ppb
2019-02-19AE548441.30 ppb
2019-02-19AE548501.60 ppb
2019-04-01AE60646ND
2019-04-01AE606482.20 ppb
2019-07-11AE741043.00 ppb
2019-07-11AE740971.000 ppb
2019-11-15AE895312.20 ppb
2019-11-15AE89534ND
2020-03-19AF037791.80 ppb
2020-03-19AF03780ND
2020-06-09AF14626ND
2020-06-09AF146271.80 ppb
2020-06-09AF146591.80 ppb
2020-06-09AF146611.70 ppb
2020-09-11AF273421.70 ppb
2020-09-11AF273431.30 ppb
2020-09-11AF273591.60 ppb
2020-11-13AF345971.10 ppb
2020-11-13AF345861.000 ppb
2020-11-13AF345842.30 ppb
2021-01-26AF41045ND
2021-01-26AF410481.60 ppb
2021-01-26AF411151.20 ppb
2021-01-26AF411171.20 ppb
2021-06-15AF580591.60 ppb
2021-06-15AF580601.000 ppb
2021-09-08AF690991.60 ppb
2021-09-08AF69102ND
2021-12-10AF786281.10 ppb
2021-12-10AF78629ND
2022-03-10AF88638ND
2022-03-10AF88639ND
2022-03-10AF88679ND
2022-03-10AF88683ND
2022-06-24AG023481.10 ppb
2022-06-24AG02352ND
2022-09-08AG120641.000 ppb
2022-09-08AG12065ND
2022-12-30AG23216ND
2023-02-16AG293172.40 ppb
2023-02-16AG293181.10 ppb
2023-02-16AG293651.000 ppb
2023-02-16AG293671.40 ppb
2023-03-29AG34750ND
2023-06-01AG427742.90 ppb
2023-06-01AG427761.40 ppb
2023-09-27AG577514.20 ppb
2023-09-27AG577522.20 ppb
2023-12-22AG673441.000 ppb