This article presents summaries of a series of expert-written "white papers" that review the best available science on potential health risks posed by nine of the most significant concerns. These white papers consolidate all of the most important findings reported in recent literature and research on the priority topics and set the stage for regulating distribution system water quality. Titles of the white papers include: The Potential for Health Risks from Intrusion of Contaminants into the Distribution System from Pressure Gradients, by American Water Works Service Co. (AWWSC); Potential Contamination Due to Cross-Connections and Backflow and the Associated Health Risks, by US Environmental Protection Agency (USEPA); Deteriorating Buried Infrastructure Management Challenges and Strategies, by AWWSC; Permeation and Leaching, by American Water Works Association (AWWA); Nitrification, by AWWA; Finished Water Storage Facilities, by AWWA; Effects of Water Age on Distribution System Water Quality, by AWWA; and, Health Risks from Microbial Growth and Biofilms in Drinking Water Distribution Systems, by USEPA.