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il I j . I .. - - 't I I ES.3 Altematives Developmemand Evaluation Eight preliminary alternatives were developed for hydraulic analysis. The eight alternatives I encompass a full range of p~sible system collfigurations, so different lewls of service to the three geographical areas and cusromer priOrlly levelscoukl be Investigated. In addilion, both centralized end decentralized storage and pumping options were included to investigate the I cost-effeclM!ness of differØnt systernconfig¡¡rations. The altematives ranged from small systems (Priority 1 and 2customarS in RedWc>OdShóres only) to City-wide systems (Priority 1, 2, and 3 cU$lomeI's i", aU threìIQeograPhlca4.areas) pIOVíding a range of new water supply from I jllSt over 1.100 AFlyr up to approxlmately 3,172 AF/yr. preliminary estimates .of capJtåI costs a/14 cost effectiveness (cost per acre-foot of water I delivered) were develOped for the eight preliminary alternatives based on pipeline sizes and lengths, stol'age andpump!nQ capacity, treatment cosl$¡ and standby connections. The conclusions drawn from 1I1e pralim1nary alternatives analys1s are as follows: I . The cost effectlveoo¡$ of City-wicle altemativeslhat seI'V6 only Priority 1 and 2 CU$tomers tends to bf) much lower than for alternatives that include Priority 3 customilrs. When the PriQrily 3 customers are added to Clty-widedis:tributlon systems. the.cost- I effectillenessincrÐ<lses by about 35%. This is bf)cause Priority 3 customers make up a large perc&ntageoftotalpQtential recycled waÌ!lJ' demand outside the Redwood Shores, and the transmissIOn pipeline system becomes mora cost-t'!fficient When the Priority 3 I customer demands are 1ncluded, - . PrelilTÛnary altematives with cenlrallzed storage and pumping at SBSA are more cost J effective than thealtemalives with decentralized storage a nd pumping. The cost required for decentrar¡zed pump stations is greater !han the cost savings realized by reduced pipeline sizes tn the transmission system. I . In .an attempt to Improw cost-effectiveness of a City-wide project While maintaining a substantial recycled waÌ!lJ' supply,fine-ttming was performed by elllTÛhat1ng distribution pipelines to cuslomei'$ that appeared tobf) relatively ElXpensjve on a cost per M'1yr I delivered basiS. /, slight Impl'OVtimentln cost effl;ctveness was re<!lized In this fine- tuning. I Based on the reStJlts of the preliminary alternatives jlvaluation.. final altemallves were developed to meet the range of the CitY's proJ$(:ted water supply mH!ds, while providing the best value and preseNing. flexibHity for Mura system groWth and expansion. All of the final alternatives . Included some level of service toPriQrity 3 custome($. The four Final Alternatives A through D are summarized In FigUJl!s ES-1 through ES-4. To preserve flexibility for future expansion of th¡o recycled water system. the Iransm1ssion pipelines are sized under each final alternative to II serve aU of the Priority 1, 2, and 3 customers In each of the three geographical areas (as In Alternative B). I ES.4 Recommended Project Based on an ev;¡¡luation of cost-effectfll'eness, water supply, and future fteXfbllity considerations, I Proj&ct Alternative D Is recommended to the City for use in projectplann!ngand I Weier Recycling Feaslbltlty SWdy fQr RedWood Olty vi