Various treatment technologies have proven effective in controlling halogenated disinfection by-products such as precursor removal and the use of alternative disinfectants. One of the most promising methods for halogenated by-product control includes removal of precursors before disinfection. Research studies in Florida indicate that membranes are effective in removing halogenated by-product precursors from certain waters. However, can membranes be used as effectively in other locations for most drinking waters so that they can be considered BAT for disinfection by-products. There are also other regulatory concerns where membranes can provide adequate treatment. Membranes can be used for removing inorganics and radionuclides. Also, with appropriate pilot-scale and field-scale data, membranes could possibly be considered BAT for meeting the Surface Water Treatment Rule requirements. In order to discuss some of these issues, a membrane workshop was held in Cincinnati, Ohio on August 6, 1990 at EPA's Andrew W. Breidenbach Environmental Research Center.