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SYSTEM EVALUATION, CAPACITY ASSURANCE, CAPITAL IMPROVEMENTS © 2025 Fischer Compliance, LLC. All rights reserved. Sewer System Management Plan licensed for San Leandro use only. Page 46 of 57 tops of the pipes). Figure ES-4 of the Master Plan shows the capacity assessment results for future peak wet weather flow conditions, indicating existing trunk sewers that were predicted by the model to be surcharged due to “throttle” conditions (peak flow exceeding full pipe capacity) or due to backwater from a downstream throttle condition, and locations of where the model predicts a surcharge condition severe enough to violate the City’s capacity criteria (defined as water level within four feet of manhole rims). Most of these locations were also predicted to be capacity issues under existing peak wet weather flows. The model predicted that no overflows would occur under design storm conditions, and no surcharge under peak dry weather flows. Furthermore, all the modeled pump stations have adequate firm capacity (capacity with largest pumping unit out of service) to convey the predicted peak wet weather flow without violating freeboard criteria or resulting in sewer overflows, although for two of the stations (Bermuda and Teagarden), some backup surcharge may occur. The model included a “time to overflow” analysis of five lift stations. The results showed that all the lift stations appear to have adequate time to avoid overflows under a shutdown due to a power outage, based on the expected time it would take City staff to reach the stations after receiving an alarm and activate an on-site backup generator or connect to a portable generator. For the smaller stations, due to limited data with which to accurately determine the storage capacity in the upstream sewers, the modeling was not sufficiently conclusive to quantitatively assess the time to overflow under a wet weather event. Spill data from the past several years do not indicate that dry weather capacity is a major contributor to spill events. However, it appears that I/I is a contributor to spill events during wet weather. The City intends to develop a procedure to identify wet weather capacity problems. EFFECTIVENESS The City utilizes the following Key Performance Indicators for measuring effectiveness of this Element: • Number of capacity-related spills or surcharge condition during the audit period. • Has the system responded to rain events as indicated by the hydraulic model? • Has there been any changes to zoning designations (residential, commercial, industrial)? IMPLEMENTATION PLAN/SCHEDULE No Plan Schedule Responsible Party Mgr. Eng Sup 8.2.1 Monitor/evaluate significant rain events to see if they exceed the design storm in the hydraulic model. Each significant rain evet X X 8.2.2 Monitor flows in each basin and update the hydraulic model Per Engineering Department schedule X 8.2.3 Develop a procedure to identify wet weather capacity problems. Beginning in 2026 X X X