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The potential recycled water demand for Priority 1,2, and 3 customers in Redwood City <br />appears to range between about 1,100 and 3,172 acre feet per year (^F/yr), for a <br />Redwood Shores only project and a City-wide project, respectively. Within these <br />projections, about 582 ^F/yr is for future developments or redevelopment projects that <br />are in various stages of planning: <br /> <br />ES.3 Alternatives Development and Evaluation <br /> <br />Eight preliminary alternatives were developed for hydraulic analysis. The eight <br />alternatives encompass a full range of possible system configurations, so different <br />levels of service to the three geographical areas and customer priority levels could be <br />investigated, in addition, both centralized and decentralized storage and pumping <br />options were included to investigate the cost-effectiveness of different system <br />configurations. The alternatives ranged from small systems (Priority 1 and 2 customers <br />in Redwood Shores only) to City-wide systems (Priority 1, 2, and 3 customers in all <br />three geographical areas) providing a range of new water supply from just over 1,100 <br />AF/yr up to approximately 3,172 AF/yr. <br /> <br />Preliminary estimates of capital costs and cost effectiveness (cost per acre-foot of water <br />delivered) were developed for the eight preliminary alternatives based on pipeline sizes <br />and lengths, storage and pumping capacity, treatment costs, and standby connections. <br />The conclusions drawn from the preliminary alternatives analysis are as follows: <br /> <br /> · The cost effectiveness of City-wide alternatives that serve only Priority 1 and 2 <br /> customers tends to be much lower than for alternatives that include Priority 3 <br /> customers. When the Priority 3 customers are added to City-wide distribution <br /> systems, the cost-effectiveness increases by about 35%. This is because <br /> Priority 3 customers make up a large percentage of total potential recycled water <br /> demand outside the Redwood Shores, and the transmission pipeline system <br /> becomes more cost-efficient when the Priority 3 customer demands are included. <br /> <br /> · Preliminary alternatives With centralized storage and pumping at SBSA are more <br /> cost effective than the alternatives with decentralized storage and pumping. The <br /> cost required for decentralized pump stations is greater than the cost savings <br /> realized by reduced pipeline sizes in the transmission system. <br /> <br /> · In an attempt to improve cost-effectiveness of a City-wide project while <br /> maintaining a substantial recycled water supply, fine-tuning was performed by <br /> eliminating distribution pipelines to customers that appeared to be relatively <br /> expensive on a cost per AF/yr delivered basis. A slight improvement in cost <br /> effectiveness was realized in this fine-tuning. <br /> <br /> Based on the results of the preliminary alternatives evaluation, final alternatives were <br /> developed to meet the range of the City's projected water supply needs, while providing <br /> the best value and preserving flexibility for future system growth and expansion. All of <br /> the final alternatives included some level of service to Priority 3 customers. The four <br /> Final Alternatives A through D are summarized in Figures ES-1 through ES-4. To <br /> <br /> Water Recycling Feasibility Study for Redwood City <br /> <br /> <br />