2022/08/10 Council Agenda Packet

City of Everett EXHIBIT A SCOPE OF SERVICES Background The City of Everett, Washington (City) has selected BHC Consultants, LLC (BHC) to provide engineering services for the WPCF TFI Bar Screen Upgrades Project. The trickling filter influent (TFI) bar screen vault has two chambers. The east chamber houses a mechanical bar screen to remove debris from the trickling filter influent coming from the primary clarifiers and return flow from the aerated lagoons, and the west chamber is used as a flow control structure which diverts secondary clarifier effluent, in excess of what is discharged through the South End Pump Station (SEPS), to the aerated lagoons. The City desires improvements related to this vault to improve capabilities for maintenance and system reliability Based on the preliminary design conducted by BHC and subsequent preparation of an engineering report, proposed improvements are to include the following: • Addition of a 36-inch bypass pipeline, precast concrete junction box, and isolation gates that will allow isolation of the east compartment for maintenance of the mechanical screen. When bypassing the east compartment, flow will be directed from Diversion Structure 2 to a junction box downstream of the east compartment. • Removing the existing modulating sluice gate in the west compartment and replacing it with a static weir for improved accuracy and reliability in controlling the minimum wet well level at the SEPS necessary to avoid vortexing of the pumps. This scope of services includes design and bid assistance associated with the proposed improvements necessary to prepare bid documents and assist the City with bidding and awarding the project for construction. The original agreement for preliminary design shall be amended to add engineering services for design and bid assistance as scoped herein. Additional work for engineering services during construction will be incorporated as a second amendment to the original agreement later. Scope of Services Task 100 —Project Management Objectives Monitor, control and adjust scope, schedule, and budget as well as provide monthly status reporting, accounting, and invoicing. Also, provide coordination with BHC staff and City personnel. BHC Services 1. Coordinate and manage the project team. 2 Subcontract with and manage project subconsultants. BHC will subcontract with HWA to review design elements related to excavation/backfill, dewatering, and soil bearing pressures for the new junction box. HWA had prepared the most recent geotechnical report for the WPCF, which looked at the same general area as the proposed improvements. Scope of Services 2 bhc CONSULTANTS