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City of Pleasanton Phase 1A Recycled Water Distribution System Design Final Draft This combination of supply scenarios will be evaluated for initial closed system conditions (serving Sports Park and other small demands without Livermore supply or Tassajara Reservoir connections), completed Phase IA improvements (with Tassajara Reservoir, Livermore connection and all Phase IA plus Oracle users connected)and for long term conditions identified as Phase 1B. Information needed from each supplier includes: • Diurnal availability of water during maximum month and peak day demand periods • Seasonal availability during low demand winter months Ability to supply recycled water into a closed system(no reservoir storage)under"on demand"operating conditions • Initial and future projected seasonal and daily supply allocations for Pleasanton • Supply interruptions scenarios that should be considered by Pleasanton • Supply operating constraints and limitations that should be considered in developing Pleasanton system operations and controls, including flow control valve at supply connections Subtask 1.2: Identify Operating Scenarios Consultant shall identify up to seven (7) operating scenarios for modeling to evaluate pipe sizing and operating conditions. Consultant shall develop the scenarios through discussions with the City. Subtask 1.3: Update Model and Perform Model Runs Consultant shall convert the City's existing static model into a dynamic model capable of simulating system performance under the three operating scenarios for three phases of system development (initial, Phase IA complete,Phase 1B complete)identified in Subtask 1.2. The model will be used to validate and refine pipe sizing required to meet minimum service pressures for customers under maximum demand conditions and under the various supply scenarios identified in Subtask 1.1. The modeling analysis will also validate and refine the sizing of the proposed recycled water pipeline in Santa Rita Road, including hydraulic performance under peak demand conditions and water age. Water age will also be modeled throughout to evaluate system turnover requirements to avoid water quality problems, including consideration of reduced pipe sizing and associated head loss to better manage water age. Supply operating constraints identified by the two suppliers will be modeled to verify feasible and acceptable distribution system operating needs. Model output will be presented using tables and system maps and results will be documented in the design report and operations plan. Task 1 Assumptions: • City will provide the existing H2OMap static model and pipeline network that matches the current recommended Phase lA and Phase 1B projects. • City will provide pipe condition information for existing pipelines that will become part of the recycled water distribution system. • Consultant will not consider Phase 2 or later system expansions under this task. • Modeled demands provided by City represent City of Pleasanton customer needs and do not need to be reassessed • City will provide customer irrigation windows for compiling diurnal (daily) demand patterns for customer types that will be the basis for the dynamic model conversion Task 1 Deliverables: • Model results will be included in design report and operations plan deliverables under Tasks 2 and 5 • Meeting agenda and summaries for up to one initial meeting each with DSRSD and City of Livermore(.pdf via email) Scope of Work Revs Page 2 of 17 August 20,2014