1. Research and Model Development, including the following sub-tasks: a. Model Selection: Consultant will support the WPCA in the selection of appropriate modeling software. b. Data Gathering, Analysis, and Existing Conditions Report: Consultant shall perform comprehensive data gathering and analysis. This includes researching and reviewing all relevant reports, studies, plans, GIS data, previously completed models, and other necessary resources to understand the existing conditions and contributing factors within the SSA. Consultant shall provide a detailed report to the Town, summarizing any missing data required to create the model and proposing a schedule and methods to obtain such data. c. Field Visits: Consultant shall perform site visits as needed to confirm system configuration, visit key facilities, and otherwise familiarize the team with the configuration and operation of the SSA. Field surveys to collect elevation information (pipe inverts, manhole rims) and/or pump station inspection and testing (drawdown tests) will be completed by WPCA staff in coordination with Consultant. d. Model Development: Using the Town GIS and other available information, Consultant will build the hydraulic and hydrologic model to support the objectives described above. 2. Model Calibration & Performance A. Flow and Rainfall Monitoring: a. Consultant will work with the Town to develop a flow and rainfall monitoring program to support the calibration of the model. b. Consultant will deliver raw and final flow and rainfall data for use in model calibration or any additional analyses requested by WPCA. c. OPTIONAL: At the request of WPCA, Consultant may complete an I/I analysis to help identify areas of the SSA with high I/I that may be candidates for I/I reduction work. B. Model Calibration: a. Consultant will calibrate the model to both dry and wet weather conditions using the flow and rainfall data collected in Task 2 above, available WPCF influent or effluent data, available pump station data (e.g., run times, flow, wet well levels, pressure), and other available data. b. Consultant will work with WPCA to develop calibration guidelines on which model calibration will be assessed. c. Consultant will use up to two historical storms for which comparative data (e.g., historical flow monitoring data, WPCF influent/effluent, etc.) is available to validate the model. C. Existing System Capacity Assessment: a. Using the calibrated model, Consultant will run up to two synthetic design storms or significant historical storms and assess the capacity of the sewer system under existing conditions. b. At least one of the storms selected should be a 5-year recurrence interval or larger storm. D. Technical Memorandum: a. Consultant will document all assumptions, inputs, calibration results, model limitations, and the capacity assessment. b. All electronic modeling files and results will be transferred to WPCA as part of the final submittal. c. If completed, Consultant will document results of all I/I analyses performed under Task 2, Sub-task c above.
