2012/09/05 Council Agenda Packet

1. 4 The preferred alternative was to redirect the creek in an open channel around the west side of the project site. This relocation and opening of the creek required substantial modifications to the site and structures to accommodate the creek and the appropriate setbacks. Work elements associated with relocating the creek include: • Evaluation of alignment alternatives and site configurations to accommodate lift station site needs and creek. • Hydraulic analysis to determine creek profile and compatibility with upstream and downstream profiles. • Creek bed and bank design to develop appropriate habitat for fish and wildlife. • Design of a bridge culvert over the creek to access the site. • Relocated structures to accommodate site layout. • Rebalance grading plan and redesign site drainage. • Provide retaining wall to accommodate generator location. • Revise site piping, landscaping and other project elements to reflect new site configuration. • Revise specifications to reflect the additional project elements. • Conduct a workshop with City staff to review site configuration. • Coordinate site design development with the City's environmental subconsultant, AMEC. 19. Additional Design Services(After 90%)—After the submission and review of the 90% complete plans and specifications by the City, additional comments were received that substantially modified elements of the project from what was presented in the 60% and 90% submittal packages. The additional services included: • Conducting two workshops with City staff to receive comments and review modifications based on comments received. • Revise layout of drywell to accommodate desired access to the drive shafts. This impacted the overall geometry of the structure, requiring a larger drywell, and the shaft support system. • Site piping modifications to provide flexibility in operation and accommodate the future installation of a force main in the Interurban Trail. • With the modifications considered substantial, a 99% submittal package was prepared to provide City staff opportunity to review and comment prior to the final, bid ready, `submittal. • Creation of a submittal list of potential contractor submittals. Task 7—Bidding and Award 5., Force Main Failure Impacts—With the recent failure of the existing lift station's force main and after the Lift Station 24 project was advertised for bid, the City reevaluated the project and decided to modify key design elements to provide the station with greater operational flexibility and mitigate surge potential to the greatest extent possible. City of Everett MURRAY,SMITH&ASSOCIATES,INC. LS 24 WO#UP 3313 July 2012 Engineers/Planners Page 4 S:\DVoigt\Sewcr Lift Sta 24_MSA_UP3313\Council and Bdgt ComWmend 5\Scope of Work 8-1012doc 126