Water and wastewater system operators will learn about chlorine and its alternatives for the primary disinfection of drinking water and treated wastewater. These alternatives may reduce disinfection by-products and eliminate the need for dechlorination. Learn the key criteria for disinfectant selection, including cost, safety, maintainability, control and monitoring considerations. Also presented are the pros and cons of chlorine dioxide and chloramines as alternatives to help reduce disinfection by-products and the benefits and features of alternative disinfectants like ozone, ultraviolet, mixed oxidant systems and peroxide. Review the various laboratory methods to determine residuals and demonstrations of some of the practical simplified test protocols. Some class time is devoted to hands-on practice of a number of residual test methods.