The emergence of a harmful algal bloom (HAB) in a water supply reservoir will place a strain on the treatment abilities of a conventional drinking water treatment plant. Historically, the primary goals of a conventional drinking water treatment facility have been to improve the clarity of drinking water, reduce odors, and prevent the spread of waterborne disease. The process ow diagram for a typical water treatment plant is shown in Figure 6.1. Processes such as coagulation, occulation, sedimentation, ltration, adsorption, and disinfection have evolved over the years to meet these primary needs. In more recent decades, these processes have been further modied and improved to remove or reduce the formation of hazardous chemicals, such as disinfection by-products, arsenic, and a host of synthetic organic compounds.