2012/09/05 Council Agenda Packet

ss `14 Modifications included incorporating the use of variable frequency drives(VFD's)to operate the pumps instead of soft starts and site piping modifications to be compatible with the Emergency Force Main Replacement project. The most significant of these modifications is the use of VFD's,which impacted the majority of the electrical drawings and certain specification sections. With the use of VFD's the pump drive shaft system was no longer a practical approach and alternative close-coupled pump systems needed to be considered. With the elimination of the drive shafts,this also impacted the layout and access in the drywell, overhead crane system and certain structural elements. With the modifications being significant,the City decided to postpone the bid opening approximately four weeks and issue an addendum that reflected the changes to the contract documents. Elements of this subtask include: • Coordination with City staff on VFD preferences and manufacturers, as well as layout of station and site. • • Evaluate alternatives for building layout with VFD's and select preferred alternative. • Review and provide information on close-coupled pump alternatives. • Consider access and drywell modifications,including overhead crane system. • Evaluate site piping modifications to be compatible with the Emergency Force Main • Replacement Project. • • Review alternatives with City and define preferred alternatives for lift station modifications. • Modify electrical drawings to represent the use of VFD's and immersible motors. • Revise building layout to be compatible with VFD installation, close-coupled pumps with immersible motors,pump access and oyerhead crane system. • Provide overhead crane system in drywell,modify crane in control room. • Modify structural design accordingly,removing drive shaft access and support systems. .• Modify civil drawings to accommodate modification to the site piping. • Provide additions to the specifications as necessary to reflect modifications. • •. Prepare an addendum to reflect modifications as define within this subtask. • Submit draft addendum for City review and receive comments. • • Prepare addendum to be issued to plan holders. • Provide updated cost estimate to the City that reflects modified project scope. Task 9—Unanticipated Services • I. Additional Surveying—At the request of the City,additional surveying services were provided to map the extent of critical areas at the site based on flagging provided by the City's environmental subconsultant,AMEC. Services included: • Site survey to locate flagging City of Everett MURRAY,SMITH&ASSOCIATES,INC. LS 24 WO#UP 3313 July 2012 Engineers/Planners Page 5 S:\DVoigt\Sewer Lift Sta 24_MSA_UP3313\Council and Bdgt Com\Amend 5\Scope of Work 8-1O12.doc 127