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2 <br /> Deliverables: <br /> • Basemap with CAD files. <br /> Task 3—Geomorphology and River Hydraulics <br /> No geomorphology was conducted in 2011 to evaluate future changes to the river bed and banks and <br /> subsequent effects on the two potential emergency outfall locations. A.geomorphic evaluation is an <br /> important part of this study and will help the City plan for a long-term solution for an operable emergency <br /> outfall. Geomorphology will be evaluated for two outfall locations,which are in near proximity to one <br /> another(approximately 800 feet apart). Alternative 2a is located at the same river station as the original <br /> outfall. Geomorphology will be conducted for this location and will evaluate both the existing outfall and <br /> the proposed changes to the outfall configuration. Alternative 2b is located approximately 800 feet <br /> downstream. <br /> WEST Consultants,Inc.(WEST)will conduct a brief geomorphic analysis for the two outfall locations <br /> (see Attachment 3). URS will coordinate work with WEST on this effort. <br /> River modeling and sediment transport analysis for the Snohomish River will be prepared by WEST as <br /> described in Attachment 3. Sediment transport will be estimated to evaluate long term potential for <br /> channel aggradation at the two proposed outfall locations. <br /> URB will use the river modeling results for the following purposes: <br /> • To provide existing in-channel hydraulic conditions for the diffuser modification alternatives. <br /> • For data input into revised mixing zone analyses for diffuser upgrades or relocation. <br /> •. To evaluate channel flow characteristics for in-stream channel improvements. <br /> • To evaluate local scour for each alternative. <br /> Deliverables: <br /> • Draft and Geomorphic and Hydraulic Technical Memorandum in electronic(PDF)format. <br /> Task 4—Pipeline Evaluation <br /> To better define Alternative 2b and compare the two alternatives,this task will need: <br /> • Bathymetric survey(Task 2), <br /> • Geomorphic analysis(Task 3), <br /> • River hydraulic assessment(river modeling,sediment transport,and local scour analysis),(Task <br /> 3), <br /> • Initial coordination with WSDOT and the USACE and/or the Coast Guard, <br /> • In depth review of the pipeline hydraulics involving the chlorine contact chamber and the river at <br /> MHHW and 100 year flood elevations,and <br /> • Review and adjustment(if needed)of the cost estimates. <br /> Determining the location of the pipeline and diffuser in the river may be impacted by easements or <br /> requirements established by WSDOT regarding the I-5 overpass and bridge supports and navigable <br /> requirements by the USACE or the Coast Guard. This task includes coordination with agencies to verify <br /> or update data in the prior study and obtain easement information from the City and WSDOT. We also <br /> will coordinate with Ecology on the NPDES permitting. The purpose of interacting with the agencies at <br /> this pre-design phase is to obtain updated information,seek input for successful NPDES permitting,and <br /> gain understanding on property ownership and easements. <br /> The in-water permitting is another larger effort that is not included at this phase. This effort would <br /> involve coordination with several agencies and preparation of several permitting documents. However,to <br /> J:\Projects\E\Everett,City of\WPCF Outfall 025\00-Project Management\Scope&Budget\2013 Pre-Design Update and Desia Phase\Scope of <br /> Work-Update Study Everett Outfall 025-02-03-14.doc <br /> Page 3 of 5 <br /> 21 <br />