Brown and Caldwell, Inc. 9/20/2023

PGSF WMVD Storm and Combined Sewer Design Scope of Work 08-25-2023 31 of 41 Category 2: Sensitive information Category 2: For official use only / disclosure permissible by law. STC will prepare and conduct a trenchless workshop to present the findings of the TM. The workshop will include analysis of the cost-weighted risks to ensure that the recommended method fits the City’s risk profile for construction. The risks analysis will inform the cost estimate to be developed during design, identify risk mitigation measures that could be included in design and will solicit feedback from the City and B&C. Discussions, conclusions, and decisions of the Workshop will be incorporated into the Final Trenchless Feasibility TM. This TM will serve as the basis for the trenchless methods selection. Task Assumptions • Information on existing geotechnical and groundwater conditions will be provided to STC by B&C. • Feasible crossing locations will be developed in conjunction with B&C. • Comparative Cost Estimates will be Level 5 • All geotechnical and groundwater assumptions in the TM are confirmed in design with site- specific geotechnical information. • STC will perform internal QA/QC prior to delivery to B&C. • Development of the TM will require a minimum of two (2), one-hour meetings with B&C. • STC will develop the workshop materials for review by B&C • All workshop materials will be reviewed by B&C and STC to determine detailed approach to the workshop. • Cost-Weighted risk analysis will be edited in real time in response to comments and concurrence with the workshop participants. • The conclusion of the workshop will be described and captured in the Final TM. • A minimum of one trenchless specific permitting meetings will be held with B&C and ESA .Associates to coordination feasibility considerations and impacts on expediting permitting. • Trenchless Methods Workshop will be approximately 2 hours in length. Everett Responsibilities • Review and provide comments on TM • Attend and participate in in the Trenchless Methods workshop. Meetings • Coordination meetings • Trenchless Methods Workshop Work Products A Draft Technical Memorandum (TM) will be developed that captures the conclusions of the trenchless feasibility study. The TM will include: • Descriptions of Trenchless Methods Analyzed • Geotechnical Conditions assumed for the analyses and additional site -specific geotechnical information that will be required to confirm the analysis during 30% to 60% design. Recommendations will be made for vertical boring locations, sampling locations, geotechnical testing, and the installation of piezometers. • Cost-Weighted Construction Risk Evaluation o Based on Level 5 cost estimates for each feasible trenchless method. • Recommended Trenchless Method • Site layout drawings for the recommended method