An Area-Wide Optimization Program (AWOP) is a multi-state effort in which states work together to develop and implement individual state programs to optimize particle removal and disinfection capabilities of conventional surface water treatment plants in each state. AWOP is designed to assist water systems work toward optimizing their existing treatment processes in an effort to increase public health protection. While originally developed to address microbial contaminants, AWOP has expanded beyond the original tools and is an ever-changing and ever-growing program that now addresses both microbial contaminants and disinfection byproducts in surface water systems. Initial steps are also being taken to investigate how to extend the optimization concept to ground water systems.