The project objective is to develop and demonstrate a pragmatic methodology for total planning of an integrated water supply-liquid waste handling system on a regional scale (county wide and larger). This will require defining the location, the size and time phasing of each treatment plant in a regional array. Existing and additional primary and secondary plants are considered along with tertiary plants, desalting, and dilution in assessing incremental improvements in water quality versus incremental costs. Both treatment costs and the costs of water transport are considered as a function of scale. The objective is to meet the projected diversion demand requirements and the quality requirements for in-stream water quality and for each utilitarian use within the system.