Source of THM'sTHM's (Trihalomethanes) are produced when chlorine reacts with residual organic compounds. The four common THM's are chloroform, dibromochloromethane, dichlorobromomethane, and bromoform. There have been studies that suggest a connection between chlorination by-products and particularly bladder and possibly colon and rectal cancer. An MCL of 0.10 mg/l for total THM's exists.
Treatment of THM'sTrihalomethanes and other halogenated organics can be reduced by adsorption with an activated carbon filter.