This paper discusses a study to identify the key components of biodegradable organic material (BOM) responsible for microbial regrowth in the distribution systems and to evaluate the efficacy of various treatment processes at removing these compounds. Because of the current dependency of the industry on the biodegradable organic carbon (BDOC) methods currently available, a component of the research also utilized and evaluated this method in treatment plants and distribution systems. The approach included laboratory studies to identify key compounds and a full-scale monitoring program to identify treatment processes and modifications to plant operation which are successful in removing these key compounds as well as BDOC.