In Canada and all the western United States, long-treated water transmission lines are frequently utilized to convey potable water to rural communities. These long transmission lines combined with chlorine for water disinfection can often create conditions that lead to disinfection byproducts (DBPs).

One of the most common DBPs is a family of volatile compounds called Trihalomethanes (THMs). THMs are regulated in Canada to a level of 100 ppb (parts-per-billion) annual average and in the U.S. to a level of 80 ppb.