This article begins by discussing the influence of softening chemicals, lime and soda ash, on the adsorption of taste and odor compounds by activated carbon. Although removal of taste and odor compounds is the primary function for activated carbon, additional benefits include: adsorption of such compounds as organic insecticides, herbicides, and detergents, which are relatively inert to chemical oxidation; removal of color and improvement of coagulation; and, reduction in substances having chlorine demand.