Agmt 2013 RMC Water and Environment

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Task 4 Deliverables: • Calibrated hydraulic model for the sewer system(model files plus data exported to GIS and/or Excel tables) Task 4 Assumptions: • RMC will use its own model licenses for the work under this project • City staff will provide record drawings and assistance with field verification if needed to obtain or confirm data for critical sewers included within the model Task 4 Schedule: • Model shall be delivered at time of submittal of final deliverables under Task 9 Task 5–System Performance Evaluation and Improvement Needs This task involves evaluation of collection system capacity and identification of specific improvement needs to address any deficiencies. Subtask 5.1 Establish Capacity Evaluation and Design Criteria and Level of Service RMC will propose appropriate design and hydraulic criteria to be used for assessing the capacity of existing sewer facilities and sizing new facilities, including Manning's"n"factor for gravity sewers or Hazen-Williams "C"for force mains, maximum d/D values, minimum and maximum velocities, slopes, and depth of cover, and pump station design and reliability considerations(e.g., firm capacity). RMC will also identify alternative approaches for defining an appropriate design storm or storms, including use of an actual historical storm or a synthetic event based on rainfall intensity-duration-frequency statistics or other methods such as the SCS Type IA distribution curve. RMC will propose criteria for evaluating the performance of the system under the design event(e.g., acceptable level of surcharge)that reflects the City's desired level of service and risk acceptance. The proposed criteria will be reviewed and discussed with City staff. Subtask 5.2 Evaluate Existing System Performance Using the hydraulic model and based on the criteria established in Subtask 5.1, RMC will evaluate the performance of the existing gravity trunk sewers, pump stations, and force mains under existing and future dry and design wet weather flows. Capacity deficiencies will be identified based on the performance criteria established in Subtask 5.1. Thematic maps and hydraulic grade line plots will be prepared to present the identified capacity problem areas. Subtask 5.3 Develop Capacity Improvement Projects This subtask includes the following activities: • Development of Alternatives and Preliminary Solutions. Using an iterative simulation process and engineering judgment, RMC will develop and test solutions to identified capacity deficiencies. Solutions may include upsizing or paralleling existing pipes, upgrading pump stations that lack sufficient firm capacity, consolidating flows in new sewers or existing sewers with available capacity, implementing flow diversions at critical locations, or sewer rehabilitation to reduce I/I. Based on preliminary model results and discussion with City staff, the alternatives will be refined and focused on the most viable solutions for more detailed project development. • Analysis of Proposed Solutions. RMC will evaluate potential project alternatives in further detail, including review of projects sites on aerial mapping or in the field. The purpose of these Consulting Services Agreement between City of San Leandro and RMC Water and Environment—Exhibit A Page 5 of 9