Jacobs Engineering Inc. 11/3/2022 Amendment 1

o Review operation of SR04 and associated LS32 pumping capacity with design team and City staff. o Review operation and potential range of adjustments for SR07 and SR08 with design team and City staff. o Review configuration of Pacific Regulator/Pine Street Diversion and alternatives for modification/improvement with design team and City staff. o Confirm CSO Tank volume and CSO bypass for historic rainfall event time series and City design storm(s). o Evaluate passive weir height and length for coordination with 36th Street Regulator design; provide recommended dimensions and settings. o Evaluate active gate operational heights and lengths for coordination with 36th Street Regulator design; recommend dimensions and settings. o Provide modeling support for passive odor control at the 36th Street Regulator. o Verify operation with pump back system from storage facility. o Evaluate Pacific Regulator configuration, weir heights and lengths associated with Pine Street Diversion; provide recommended configuration and settings. o Confirm Pine Street diversion pipe sizing. o Evaluate opportunities to phase storage and Pacific Regulator improvements and potential settings/modifications at SR07 and SR08 for phasing. o Evaluate the expected overflow frequency of SR04, SR07, and SR08 with the storage project and Pine Street/Pacific Regulator improvements in place.The expected overflow frequency will also be evaluated without the Pine Street/Pacific Regulator improvements to understand impact if the diversion project is postponed. Work will include phasing analysis of the following: ■ Construction completion of the storage tank prior to the Pacific Regulator and Pine Street diversion improvements ■ Construction completion of both the storage tank, and the Pacific Regulator and Pine Street diversion improvements o Identify potential hydraulic impacts of the proposed improvements on downstream conveyance and treatment facilities. o Coordinate modeling of CSO Storage Facility at 36th Street with the Sewer 0, Phase 2 project to confirm pipe sizing is adequate with storage and regulator controls. Modeling coordination will include use of the 14-storm series with climate change and 2055 storm to infrastructure sizing and operation.The City will provide updated Sewer 0 plan and profile drawings at each design phase for reference. o Document the modeling data used to calculate the controlled 20-year moving average of discharges once improvements are implemented o Develop preliminary hydraulic model deliverable and provide to the City. o Develop draft hydraulic modeling TM. Odor Control Analysis April 2022 Page 16 of 35 Jacobs Engineering Group