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7.3 Capacity Analysis Evaluate existing system performance under dry and wet weather conditions using the calibrated H/H model and updated historic rainfall timeseries from Task 6.2. Identify system deficiencies using the established planning criteria from Task 4. Perform iterative modeling where system bottlenecks are removed in capacity restricted area to account for downstream impact, thus establishing unrestricted peak flows through the system. Export simulated peak flows from the model and compare to the system deficiency criteria identified in Task 4.1 for the collection system. Compare peak flow with pipe capacity in a database that links model output data with the pipe hydraulic capacity to determine deficiency extent and compute appropriate pipe diameter to address the deficiency. Update the calibrated H/H model loading for the 20-year planning horizons. Evaluate future system performance and level of service for dry and wet weather and identify system deficiencies using the planning criteria established in Task 4.1 and the same iterative methodology used for existing system evaluation. Develop level of service (LOS) maps for the existing system and 20-year planning horizon by comparing simulation results using the design rainfall timeseries with the identified deficiency criteria. A GIS layer to be provided along with the maps. 7.4 Sewer System Evaluation Workshop Conduct a workshop with City staff to review the results of the system analysis and inventory of feasible alternatives, e.g. alternative piping alignments, pump station capacity upgrades, basin interconnections, and/or pipe upsizing. 7.5 Pump Station Condition Assessments Develop pump station condition assessment criteria and tracking forms. Each criterion to have a numeric score associated with it based on importance to facilitate ranking pump stations based on condition needs.Submit criteria and forms to City for approval prior to assessing pump stations. Conduct pump station condition assessment site visits with City staff. Evaluate the condition of major station components by visual inspection documenting the general condition of the structural, electrical, and mechanical systems that comprise the stations. Assign a condition rating to document the site visit using the tracking form. 7.6 Collection System Pipe and Manhole Condition Assessments Perform desktop collection system condition assessment of piped system and hydraulic structures based on information provided by the City such as pipe age, material, and known issues. Compile information in a spreadsheet and assign condition score. Provide recommendation on scoring methodology to be approved by the City prior to scoring assets. The score to be based primarily on age, material, and known issues. The consultant will be given a sampling (assume maximum 30 City of Everett MURRAYSMITH 2023 Comprehensive Sewer Plan March 2021 13