Know Your Environment. Protect Your Health.

Chloroform

Watertown Water & Sewer Authority

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.

 

96

Samples

0

Samples exceeding legal limit (MCL)

96

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201856.2 ppb161625.4 ppb - 87.6 ppb
201953.5 ppb161624.1 ppb - 79.9 ppb
202053.9 ppb161626.2 ppb - 98.0 ppb
202156.0 ppb161623.6 ppb - 89.1 ppb
202246.4 ppb161632.0 ppb - 70.9 ppb
202345.0 ppb161623.5 ppb - 81.1 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
2018-03-07DBP 20048953441.2 ppb
2018-03-07DBP 20048953546.3 ppb
2018-03-07DBP 20048953647.3 ppb
2018-03-07DBP 20048953355.1 ppb
2018-06-06DBP 20049632870.0 ppb
2018-06-06DBP 20049632964.7 ppb
2018-06-06DBP 20049633060.5 ppb
2018-06-06DBP 20049633164.9 ppb
2018-09-05DBP 20050406175.9 ppb
2018-09-05DBP 20050406287.6 ppb
2018-09-05DBP 20050406373.9 ppb
2018-09-05DBP 20050406459.4 ppb
2018-12-05DBP 20051498043.8 ppb
2018-12-05DBP 20051498242.5 ppb
2018-12-05DBP 20051498139.9 ppb
2018-12-05DBP 20051497825.4 ppb
2019-03-06DBP 20052370850.1 ppb
2019-03-06DBP 20052370936.2 ppb
2019-03-06DBP 20052371039.0 ppb
2019-03-06DBP 20052371129.5 ppb
2019-06-05DBP 20053506861.1 ppb
2019-06-05DBP 20053506973.2 ppb
2019-06-05DBP 20053507054.6 ppb
2019-06-05DBP 20053507161.4 ppb
2019-09-05DBP 20054763779.9 ppb
2019-09-05DBP 20054764066.8 ppb
2019-09-05DBP 20054763975.2 ppb
2019-09-05DBP 20054763679.2 ppb
2019-12-05DBP 20055914724.1 ppb
2019-12-05DBP 20055914841.1 ppb
2019-12-05DBP 20055914931.4 ppb
2019-12-05DBP 20055914653.3 ppb
2020-03-04DBP 20056819751.4 ppb
2020-03-04DBP 20056819827.0 ppb
2020-03-04DBP 20056819935.6 ppb
2020-03-04DBP 20056820026.2 ppb
2020-06-03DBP 20057785549.5 ppb
2020-06-03DBP 20057785651.3 ppb
2020-06-03DBP 20057785446.4 ppb
2020-06-03DBP 20057785365.8 ppb
2020-09-02DBP 20058867998.0 ppb
2020-09-02DBP 20058868079.2 ppb
2020-09-02DBP 20058868167.6 ppb
2020-09-02DBP 20058868276.3 ppb
2020-12-02DBP 20059979157.5 ppb
2020-12-02DBP 20059979235.0 ppb
2020-12-02DBP 20059979348.6 ppb
2020-12-02DBP 20059979447.4 ppb
2021-03-10DBP 20060934937.9 ppb
2021-03-10DBP 20060934649.4 ppb
2021-03-10DBP 20060934723.6 ppb
2021-03-10DBP 20060934835.5 ppb
2021-06-02DBP 20061913748.3 ppb
2021-06-02DBP 20061913953.1 ppb
2021-06-02DBP 20061914063.0 ppb
2021-06-02DBP 20061913674.2 ppb
2021-09-08300053894 30005389671.4 ppb
2021-09-08300053900 30005390274.9 ppb
2021-09-08300053903 30005390565.0 ppb
2021-09-22300065698 30006570089.1 ppb
2021-12-01D300110687 30011068952.2 ppb
2021-12-01D300110684 30011068653.8 ppb
2021-12-01D300110681 30011068343.6 ppb
2021-12-01D300110678 30011068060.3 ppb
2022-03-02D300151783 30015178538.8 ppb
2022-03-02D300151786 30015178836.8 ppb
2022-03-02D300151789 30015179132.0 ppb
2022-03-02D300151792 30015179437.1 ppb
2022-06-01D300192098 30019210054.2 ppb
2022-06-01D300192101 30019210346.6 ppb
2022-06-01D300192104 30019210646.6 ppb
2022-06-01D300192107 30019210949.3 ppb
2022-09-14D300244033 30024403565.9 ppb
2022-09-14D300244027 30024402949.1 ppb
2022-09-14D300244024 30024402670.9 ppb
2022-09-14D300244030 30024403262.5 ppb
2022-12-07D300282718 30028272039.8 ppb
2022-12-07D300282721 30028272334.6 ppb
2022-12-07D300282724 30028272639.3 ppb
2022-12-07D300282727 30028272939.2 ppb
2023-03-16D300321892 30032189438.5 ppb
2023-03-16D300321895 30032189723.5 ppb
2023-03-16D300321898 30032190035.1 ppb
2023-03-16D300321901 30032190327.0 ppb
2023-06-14D300365450 30036545232.2 ppb
2023-06-14D300365456 30036545843.2 ppb
2023-06-14D300365453 30036545543.9 ppb
2023-06-14D300365447 30036544949.8 ppb
2023-09-06D300410877 30041087978.5 ppb
2023-09-06D300410880 30041088272.6 ppb
2023-09-06D300410883 30041088575.0 ppb
2023-09-06D300410886 30041088881.1 ppb
2023-12-07D300456855 30045685730.8 ppb
2023-12-07D300456858 30045686025.2 ppb
2023-12-07D300456861 30045686332.3 ppb
2023-12-07D300456864 30045686631.5 ppb