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Mr. Stephen Kirkpatrick P.E. The City of Pleasanton October 17, 2012 Page 2 Task 1.1 —Review Existing Data. This task includes a review of the current data from the following sources. Carollo has the majority of this information on file, however the City may be required to provide some additional information. • Dublin San Ramon Sanitary District Wastewater Treatment Plant (DSRSD WWTP) influent flow data • Historical East Amador Lift Station flow and run time records • Historical Dry and Wet Flow Monitoring Data collected as part of the 2007 Wastewater Master Plan • Final 2007 Wastewater Collection System Master Plan • Temporary Flow Monitoring Program data collected during 2012 • Existing Land Use data from the Citys General Plan • Existing vacant land data for the areas of the system tributary to EATS • As-built drawings for the East Amador Relief Sewer(EARS),and the EATS projects The data review will help develop the existing wastewater flow rates tributary to the EATS system, project future flow, and help establish and verify the hydraulic conditions, and the planning and evaluation criteria used as part of the 2007 Plan. The data will set the foundation for the model update. Task 1.2—Convert Hydraulic Model. Carollo will use the Citys existing hydraulic model files and import it into the MapSWMM software. The conversion will include importing modeling parameters for the following scenarios: • Existing Average Dry Weather Flow • Existing Peak Wet Weather Flow • Build-out Average Dry Weather Flow, and • Build-out Peak Wet Weather Flow Task 1.3—Calibrate Hydraulic Model. Once the model has been updated and converted to current flows, it will be recalibrated to ensure it accurately simulated the conditions in the field. Dry weather flows will be calibrated first using the summer 2012 flow monitoring data. Wet weather flows will be calibrated using, historical rainfall data, and flow data from DSRSD, as well the flow monitoring program conducted for the 2007 Master Plan. The model will be considered calibrated when the model simulated flows match the field measured flows to within 10 percent for peak, minimum and average flow conditions for the dry weather conditions. The model will be deemed calibrated for wet weather when the peak flows are within 10 percent of the measured flows for a minimum of two distinct storm events. Task 2— Document Model Conversion. Carollo will attend one meeting with the City to discuss the model conversion and calibration. Carollo will also develop a technical memorandum (TM) summarizing the model conversion and update process. The TM will specifically focus on the results of the model calibration. Carollo will submit an electronic copy of the TM to the City for review prior to the meeting. pw//Cardlo/Documents/ClenUCNPleasantoN_Proposels/EARS Pump Stason/DOCyEARS Scope Letter(S) carollo.com