Throughout the United States (U.S.), a number of utilities have been impacted by arsenic, perchlorate, and nitrate found in water supplies as more stringent regulations are being implemented. Arsenic occurs naturally in the environment, and it is also widely used in timber treatment, agricultural chemicals (pesticides), and manufacturing of gallium arsenic wafers, glass, and alloys. Perchlorate contamination is typically associated with facilities that once manufactured, handled, or stored ammonium perchlorate, a solid-rocket fuel, although other sources have been suggested for the cases where there is no identified source of contamination (Jackson et al. 2003). For nitrate, run-off from agricultural lands treated with nitrogen fertilizers has been recognized as the main source of occurrence. The majority of the technologies for treating these three contaminants produce a concentrated waste stream that requires special handling and treatment prior to disposal. The disposal of these wastes can sometimes be very costly or not viable depending on the local discharge regulations. Thus, in selecting treatment alternatives, residuals discharge and disposal issues should be carefully considered in order to avoid additional costs associated with handling residuals. Includes 33 references, tables.