2013/04/17 Council Agenda Packet

Background The original contract scope of services provided for design and preparation of a single construction document package for sewer system replacement and capacity improvement in three separate locations,referred to as L-North;L-East(now indentified as East Grand);and Hayes Street Combined Sewer Overflow(CSO)Reduction at SRO2.Previous contract amendment authorizations provided for additional hydraulic analysis and design services related to the"L-North project area and systems downstream,as well as tributary systems to the Siphon Headworks that affect CSO at SRO2 and SRO1.This amendment is for additional requested design and hydraulic analysis services for East Grand sewer replacement and stormwater separation and Hayes Street CSO Reduction(at SRO1 &SRO2),but also includes budget adjustments for previous authorizations related to deleted,un-used,or tasks that are modified by this amendment. East Grand Sewer Replacement and Stormwater Separation Design and construction plans for the East Grand combined sewer system replacement project are 60%complete. (Originally designed as a part of the sewer system"L-North"construction documents that were split-out,i.e.completing design and construction on"L-North"and deferring the other project area improvements as a future separate bid package). The City now desires to 1) separate the storm drainage and sanitary sewer flows within the East Grand area,2)replace additional segments of combined sewer,and 3)prepare final design and construction documents for the sewer replacement and storm water separation improvements. (Refer to Figure 1) The scope of services in this amendment for the East Grand Sewer Replacement and Stormwater Separation Improvements provided for: • Preliminary design for replacement of additional existing sewer system: o 8-inch main on E.Grand Avenue from 21'Street to 20th Street. o 8-inch main in alley between Cleveland/East Grand from 21st Street to 20th Street. o 8-inch main on 21st Street from alleyway to Cleveland Avenue. o 8-inch main on Cleveland Avenue from 21st Street north to end of system. • Performing hydraulic analysis and preliminary design for installation of a new separate storm drainage pipe network comprised of catch basins,stormwater treatment facilities,and underground pipes for separating stormwater from the sanitary system within the proposed East Grand project area. • Performing final design and preparation of two separate sets of construction documents(plans, specifications,and cost estimates) for the East Grand Sewer Replacement and Stormwater Separation Improvements anticipated being bid and constructed separately over two consecutive construction seasons.Services include support for Public Involvement and Construction assistance for each of the two project phases. Sewer System Replacement and Capacity Improvements Project 2 otak K:\project\31500\31520\Contract\Amend4\AmendFour\AmendmentFour021413.docc 3