Brown and Caldwell Inc. 3/9/2022 Amendment 1

Portal 4 Improvements Geotechnical Services Scope of Work • Provide geotechnical services during construction including the following: o Inspection/testing of native and imported backfill materials o Observation/testing of footing or compacted aggregate leveling pad for valve vaults o Review and respond to RFI and submittals (assume 4 each) Part 2 of 3: Design Information Provide, at a minimum, the following information for the design and preparation of technical specifications for this project. General • Final grade fill requirements. • General site and/or slope stability modifications. • Water table elevations (seasonal highs and average); however, worst-case flood elevations shall always be considered and should appropriately govern designs and recommendations. Water elevations in bores should not be considered a reasonable design elevation without further consideration of seasons, events, or other. Confer with the City and BC prior to written recommendations. • Boring locations, including coordinates to be provided to the survey subconsultant. • Frost depth for various utilities. • Frost depth for footings (valve vaults). • Identification and extent of unsuitable (including expansive)soils and recommended mitigation measures. • Dewatering and drainage recommendations so that a contractor has adequate information to estimate the system needs. • Soil and groundwater corrosion potential/soil resistivity for buried valves and vaults. • Soil erosion potential and preventive recommendations. • Structural fill material recommendations. • Suitability of native materials as fill material for structures, embankments,trenches, etc. • Soil compaction requirements. • Classification of soil types and description of soil characteristics for all soils encountered at the site, and for any imported soil fill requirements. • Recommended temporary excavation slopes. • Recommended permanent fill slopes. • Excavation limitations. • Constrained soil modulus. • Use of agency/client standards and potential modifications. • Historic structures, trees, levees, creek alignments, etc. that could impact the design. It is assumed that reporting of these conditions will be a minor level of detail regarding how they impact the design and not a comprehensive reconnaissance of all in-ground features. IBrownANDCatdwetl 2 Attachment A Geotech Sc,vices SOW