A rigorous yet practical basis for applying the principles of physical chemistry to understanding the composition of natural waters and to the engineering of water and wastewater treatment processes. Topics covered include chemical equilibrium and kinetics; computer-aided problem solving; solid precipitation and dissolution; acid-base equilibria and buffering; oxidation and reduction reactions; sorption on solids; and coagulation and softening. Two laboratory sessions illustrate chemical principles of dilute aqueous systems. Prerequisites: general chemistry and 12-655 or equivalents.