What contaminants are removed through drinking water treatments?
Raw water is treated by physical and chemical processes to remove contaminants. The standard treatments in Canada are coagulation, flocculation, sedimentation, followed by filtration and chlorination. Coagulation, flocculation, sedimentation and filtration remove dirt, bacteria, viruses and other impurities from the water. The final treatment is the addition of chlorine to disinfect and eliminate any organisms that might have survived the filtration process. Although these treatments do reduce the contaminants in drinking water, they are not designed to remove organic or inorganic chemicals, or radiological contaminants. Chlorine itself can combine with naturally occurring organic material in the water to form trihalomethanes.
