CSA Terraphase Re Landfill Flooding 10172022

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Consulting Services Agreement between City of San Leandro and Last revised 10/10/2022] Terraphase for Tony Lema landfill climate vulnerability assessment Exhibit A – Page 3 of 4 Preparation of the Long-Term Flood Protection Plan will include developing a draft version for review by the City of San Leandro, revisions, and completion of a final version that addresses City comments. Task 3A: Vulnerability Assessment The vulnerability assessment section of the Plan will identify existing features that may be vulnerable to future flooding extents. Items to be considered include, among others, long -term cap stability, infiltration of water into the landfill waste mass, increase in leachate amounts, leachate and landfill gas migration to other aquifers or surface waters, subsidence, erosion, stability of saturated landfill waste mass, and qualitative structural stability of buildings constructed on top of the landfill. Task 3B: Adaptation Plan The adaptation plan section of the Plan will identify strategies and potential Site improvements which can be implemented over various time periods to improve resilience of the landfill in response to future flooding extents. The adaptation plan will include conceptual descriptions of strategies which may i nclude berms, groundwater containment areas, ponds, subsurface conduits, golf course irrigation/maintenance practices, and nature-based approaches, among others. Improvements required to increase monitoring efforts, such as methane monitoring, setting survey monuments for settlement monitoring, and installing groundwater piezometers for groundwater monitoring will be recommended in the Plan. A schedule of the recommended strategies and monitoring efforts on a timeline relative to future flooding extents wil l be developed. Task 3C: Maps Approximately six maps will be prepared in order to illustrate the existing and future conditions landfill features, flooding extents, and potential Site mitigation recommendations. Maps will be incorporated into the draft and final versions of the Plan. Task 4: Project Management Task 4 will include project management tasks such as project administration and accounting over a period of six months, ongoing meetings and coordination with City of San Leandro, and a meeting with the SFRWQCB to solicit feedback on the Plan. Assumptions This proposal and budget include the following assumptions:  Additional meetings with regulatory agencies outside of those described above are not included.  No field based topographic or utility surveys or setting of survey monuments are included.  Purchase or installation of any monitoring devices, wells, or otherwise, is not included.  Construction documents and detailed engineering design documents for potential Site improvements are not included.  City of San Leandro will provide Terraphase access to the Site.  City of San Leandro will provide available Site background information.  Site flood quantification and justification will be based on methods described under Task 2above and would not include development of a detailed numerical groundwater model. Existing and projected future groundwater level estimates will utilize currently available information to characterize groundwater elevations at the Site. Initial groundwater elevations and rise estimates will rely on either currently available leachate collection well data (if deemed suitable) and/or other adjacent groundwater elevation data (available from GeoTracker or other sources). DocuSign Envelope ID: 974C2867-84D8-4D0B-8A87-C4E791D70B9A