A pilot-scale pipe distribution study was conducted to determine the effect of blending different source waters on distribution system water quality as a part of AWWARF and Tampa Bay Water tailored collaboration project. In this study, finished waters from seven different processes were blended in varying ratios before distributing to eighteen pilot distribution systems (PDS) and various chemical and biological water quality parameters were monitored for a total of 12 months. This paper addresses copper release under various source water blending based on equilibrium modeling, surface characterization, and pilot observations. Includes 14 references, tables, figures.