Chloroform
Little Hocking Water/sewer Association
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.300 ppb | 2 | 1 | ND - 0.600 ppb |
| 2019 | 0.250 ppb | 2 | 1 | ND - 0.500 ppb |
| 2020 | 0.250 ppb | 2 | 1 | ND - 0.500 ppb |
| 2021 | 0.700 ppb | 2 | 2 | 0.400 ppb - 1.000 ppb |
| 2022 | 0.350 ppb | 2 | 2 | 0.1000 ppb - 0.600 ppb |
| 2023 | 0.533 ppb | 3 | 3 | 0.1000 ppb - 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 |
|---|---|---|
| 2018-07-19 | A180621836 | 0.600 ppb |
| 2018-07-19 | A180621837 | ND |
| 2019-08-15 | 9H02853-01 | ND |
| 2019-08-15 | 9H02853-02 | 0.500 ppb |
| 2020-08-20 | 0H03226-01 | 0.500 ppb |
| 2020-08-20 | 0H03226-02 | ND |
| 2021-08-19 | 1H03320-01 | 1.000 ppb |
| 2021-08-19 | 1H03320-02 | 0.400 ppb |
| 2022-08-11 | 2H02405-01 | 0.600 ppb |
| 2022-08-11 | 2H02405-02 | 0.1000 ppb |
| 2023-07-20 | 3G03485-01 | 0.800 ppb |
| 2023-07-20 | 3G03485-02 | 0.1000 ppb |
| 2023-08-17 | 3H03328-01 | 0.700 ppb |