Tacoma Water's Second Supply Project will finally bring the needed water to the South King County and Pierce County areas. It has taken over three decades to acquire the property rights, approvals, agreements, permits and funding for the project. In the mid-1980s three South King County utilities (Lakehaven Utility District, Covington Water District and the City of Kent) joined Tacoma as partners in the project. The project involves a 34 mile long steel transmission main, additions and improvements to the Green River diversion facilities, new water treatment facilities, additional water storage behind the Corps of Engineer's Howard Hanson Dam and numerous environmental enhancement projects. The Green River has provided the primary water supply by gravity flow to Tacoma through Pipeline No. 1 since 1913. Since then Tacoma has supplemented the river supply with nearby groundwater supplies during the higher demand periods of the summer. As a result, Tacoma has extensive experience with the blending of the two supply sources and has implemented operating procedures and treatment to assure acceptable water quality. However, the other project partners have little or no experience integrating surface water into their existing well supply systems. This paper presents some of the special water quality considerations the other three project partners are making. Includes table, figure.