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K <br />ATTACHMENT 1 <br />MUN AND SAWYER <br />Environmental Engineers & Scientists <br />Hazen and Sanyer, P.C. <br />629 Green Valley Road <br />SLite 200 <br />Greensboro, NC 27408 <br />336-292 -7490 <br />Fax: 336 - 292-5614 <br />October 26, 2012 <br />Mr. Sydney Paul Miller, P.E. <br />Water Resources Engineer <br />Department of Public Works and Utilities <br />Town of Cary <br />400 James Jackson Ave. <br />Cary, NC 27513 <br />Re: Jordan Lake Partnership <br />Potable Water Interconnection Study <br />Phase 2: Hydraulic Modeling Proposal <br />Dear Mr. Miller: <br />Hazen and Sawyer is pleased to submit this updated proposal for hydraulic modeling of potable <br />water interconnections among the Jordan Lake Partners. This version of the proposal responds to <br />the discussion at the partner's meeting October 16, 2012. <br />The purpose of this study is to develop a regional approach for planning interconnections that <br />increase the reliability and sustainability of drinking water by using resources cooperatively. <br />Our December 1, 2011, technical memorandum summarized Phase 1 of the project. This summary <br />tabulated each partner's water facilities, documented existing interconnections and evaluated <br />opportunities for improved interconnections. The key deliverable was a map showing all the <br />partners' water systems, pressure zone boundaries and the interconnection locations. <br />Our December 20, 2011, technical memorandum outlined the next steps for evaluating <br />interconnections by providing a modeling overview; an explanation of issues involved with <br />combining and updating models; and recommendations for moving forward. <br />This updated proposal for the project's second phase integrates interconnection modeling requests <br />by the partners and their feedback on the scope and cost estimates from previous proposals. <br />Interconnections will be evaluated for sustained transfers using multi -day extended period <br />simulations. Predicted hydraulic performance will be compared with design criteria for velocities, <br />pressures and tank water levels. Calibration tasks will focus on existing interconnections; broader <br />calibration will be recommended if a partner's model is unable to match field measurements. <br />The following pages outline the requested modeling projects. Part 2 builds on Part 1 so that tasks <br />are not repeated. Projects that involve wheeling water through an intermediate system may involve <br />the same interconnections as direct transfer projects, but these are separate modeling scenarios <br />that produce different flows and pressures. The numbers included in each project description refer <br />to the interconnection I Ds on the map from our December 1, 2011, technical memorandum. <br />