This Phase III report presents conceptual designs and cost estimates for a regional wholesale water treatment and conveyance system serving Lake Tenkiller area. Phase III extends the system designed in Phase II to the eastern reaches of Sequoyah County. Three alternatives were developed in sufficient detail to arrive at a wholesale treated water cost per thousand gallons. Treatment plant capacities, conveyance line sizes, pumping station capacities, water tower sizes, and estimated construction costs were developed for each alternative. Gross appraisals of necessary real estate to be obtained were also determined for each alternative. In addition, possible environmental concerns that could impact construction of the alternatives were addressed.