Brown and Caldwell Inc. 3/9/2022 Amendment 1

,71`=r Treatment Plant Portal 4 Impro, c.,,±- I Scope of`,"ar4< control of Consultant.Actual bids received and costs incurred may vary from the estimate ranges prepared by Consultant. All estimates are expressly implied to have 90 to 95% confidence limits. • Task includes a contingency for a third party review of the geotechnical reports (Earth Mechanics). Meetings • Final design (90%) review workshop. Assume workshop will be attended by six BC staff for a duration of two hours. • Assume three site visits attended by two BC staff for a duration of four hours on site. Work Products • This task includes development of final (90%) and bid (100%) design documents. The design plan set will include approximately 34 drawings including general sheets, notes, symbols and legends, and specifications. • The Issue for Bid deliverable will contain all drawings and specifications required for bidding. The Issue for Bid package will be stamped/sealed and digitally signed. Issue for Bid Documents will be provided in electronic format for full-size and half-size document production. • CAD files of final designs. • AACEI Class 1 construction cost estimate. Task 601 Geotechnical Services Activities/Approach: Provide geotechnical services in support of the design of the new valve vaults and vaults and to assess condition of the slope above the Portal 4 structure. The following section summarizes the geotechnical scope of work. A full description of the geotechnical services is included as Attachment A. • Review existing geotechnical reports and data for the project area. • Explore and classify the subsurface soil conditions within the vicinity of the proposed valve and vault installation locations. • Investigate the slide on the hill side southeast of the Portal 4 structural to inform mitigation. This investigation will provide information for general site and/or slope stability modifications. • Develop geotechnical engineering recommendations for design and construction of the new valve and vault locations, including_ o Construction dewatering o Temporary excavation slopes/support o Vault foundations o Groundwater elevations o Structural fill o Seismic considerations • Two(2) geotechnical borings (40 feet deep) at the location of the valve/vaults and one (1) geotechnical boring(60-80 feet deep) near the slide on the hill side southeast of the Portal 4 structure. Everett Responsibilities • Provide site access, staffing, and resources to support field work conducted by geotechnical crews. Task Assumptions • Geotechnical investigations require two site visits for utility locates prior to the field explorations. Page 9 of 13