Terraphase Soil Analysis CSA Update 2022 11 21.pdf

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Consulting Services Agreement between City of San Leandro and Last revised 11/21/2022 Terraphase Engineering, Inc for Soil Risk Analysis Exhibit A – Page 2 of 3 As part of Task 2, Consultant will: • Review existing site environmental and geotechnical data on the stockpiled soil and former polishing pond sludge. • Evaluate whether additional characterization of the soil stockpile and former polishing pond sludge is required. • Review construction details for the former polishing pond. • Review groundwater data from monitoring wells adjacent to the pond. • Evaluate the feasibility and potential risk to the environment of the following actions: o Action 1: Leaving the sludge in its current location. o Action 2: Moving the stockpile into the polishing pond without any pre-treatment. • Evaluate options for reducing potential risk of Actions 1 and 2. • Evaluate the potential risk or impact of placing stockpile soil (with or without solidification/cement stabilization) to the proposed future use of the pond as a treatment wetland area, as follows: Evaluate potential leaching of constituents from stockpile soil and sludge to groundwater. Screen laboratory data against appropriate and relevant regulatory screening criteria. Review of constituents that may affect reuse or disposal options. • Evaluate past and current regulatory requirements for management of soil/sludge at sites such as the WPCP. Task 2 Deliverable Consultant will prepare a Technical Memorandum (Tech Memo) summarizing the results of the evaluation. The Tech Memo will include a discussion of regulatory requirements, risks associated with the various potential actions, and recommendations. Consultant will prepare and submit a draft Tech Memo for review by City personnel. Consultant will make revisions based on the City’s comments and will issue a final Tech Memo. Task 2 Delivery Date The draft Tech Memo will be completed 6 weeks after authorization/notice to proceed. Completion of the final Tech Memo will be contingent on the receipt of all City comments and the extent and nature of City comments. (Optional) Task 3 – Sludge Measurement and Geotechnical Evaluation If the evaluation performed under Task 2 shows that the potential placement on and/or mixing of stockpile soil with the pond sludge is feasible, Consultant will measure the depth of the former polishing pond DocuSign Envelope ID: B65CF6DA-BB07-4010-88DC-BDA1A7ACF5A8