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Task 2.1 Site Assessment/Preliminary Design <br /> The Consultant will: <br /> 1. Review the City's existing as-built and GIS information. <br /> 2. Develop contributing area basin delineations to proposed treatment site. <br /> 3. Preform hydrologic modeling and design flow documentation. <br /> 4. Develop preliminary treatment facility sizing and facility costs <br /> 5. Develop recommended facility type and location. <br /> Assumptions: <br /> • The City will provide available data for this project including as-built drawing information for <br /> storm,water,and sewer systems. <br /> • The Consultant will review up to three potential facility locations along 3rd Ave SE for selection <br /> of single preferred facility location. <br /> • Basin delineations will be based on City provided GIS data and field verifications. <br /> • Design flows will be based on hydrologic modeling using the Western Washington Hydrologic <br /> Model(WWHM) <br /> • Treatment facility will provide a minimum Basic Treatment standard,but potential for Enhance <br /> Treatment will be evaluated. Enhanced treatment will be provided if feasible. <br /> • Up to three types of proprietary treatment systems will be evaluated per site constraints and cost <br /> comparisons. <br /> • Up to three preliminary water quality layout exhibits will be developed based on GIS data. <br /> • A pretreatment facility will be provided upstream of the water quality treatment facility. <br /> • Conveyance capacity of proposed pipes and downstream connection pipe will be evaluated using <br /> Rational Method and Manning's flow-flow analysis. <br /> • Backwater analysis using SWMM will not be required. <br /> Deliverables: <br /> • Basin Delineation Figure(PDF). <br /> • Proposed water quality system exhibits,up to three(PDF). <br /> Tasks 3.4 Preliminary Design Report <br /> The Design Report will consist of the following elements per Ecology's"Design Deliverables for <br /> Stormwater Projects with Ecology Funding": <br /> • Introduction <br /> • Basin Description <br /> • Site Description <br /> • Minimum Requirement/Core Element Analysis <br /> • Alternatives Considered <br /> • Design Analysis <br /> • Quantify the Water Quality Benefit <br /> • Engineer's Opinion of Probable Cost <br /> • Proposed Schedule <br /> City of Everett <br /> 3'd Ave SE Water Quality Treatment Page 5 of 10 <br />