Jacobs Engineering Inc. 11/3/2022 Amendment 1

1. Characterize soil conditions and evaluate how ground water depths and flows impact foundation design and construction considerations for the purpose of planning excavation support systems, dewatering system construction considerations, CSO tank construction, utility trenching,trench backfill, pipe loading,subgrade preparation, and development of subgrade repair strategies for pavement support where unsuitable subgrade soils are encountered. Additionally, seismic design assessments will be performed to include seismic hazards such as liquefaction. 2. Prepare geotechnical design and recommendations report including: o General descriptions of site conditions and subsurface soil conditions encountered based on findings presented in the Geotechnical Data Report. o Provide recommendations for earthwork and site preparation including suitability of on- site soils for reuse in storage tank and associated major structures backfill,trench backfill, placement and compaction of backfill,and mitigation of unsuitable soil conditions. o Perform engineering analyses and provide conclusions and recommendations for foundation support, buried walls, hydrostatic uplift considerations and construction considerations including dewatering and shoring. o Structures design; and conventional trenching techniques including the following: • Geotechnical parameters for construction contractor's shoring design including lateral pressures and temporary shoring considerations. • Excavation and temporary slope considerations. • Foundation support including bearing capacity and settlement; including seismic design considerations. • Construction dewatering considerations including depth to groundwater and estimated permeability coefficients based on pump testing and laboratory sieve analyses. o Evaluate and provide recommendations for pavement subgrade preparation and confirm City pavement design thickness standards are appropriate.This will include strategies for removal and replacement of soft subgrade soils using geotextiles or various import materials. 3. Prepare draft and final Geotechnical Engineering Report. Deliverables(Storage Tank Site): 1. Exploration Plan for Storage Tank Site— 1 electronic file (PDF). 2. Draft Geotechnical Data Report Storage Tank Site—1 electronic file (PDF). 3. Final Geotechnical Data Report Storage Tank Site—1 electronic file (PDF). 4. Draft Geotechnical Engineering Report Storage Tank Site—1 electronic file (PDF). 5. Final Geotechnical Engineering Report Storage Tank Site—1 electronic file (PDF). 6. Updates to Geotechnical Engineering Report at 60% and 90%, as needed—1 electronic file (PDF). April 2022 Page 12 of 35 Jacobs Engineering Group