Agmt12 G&E Engineering System Inc.

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be selected to try to avoid underground utilities; and be sloped to avoid the need for temporary shoring. • Consultant will inspect the top one foot (or so) of uncovered piles at the edges; and examine the surface soil samples / ground water conditions. If feasible and located close enough to the edges without requiring excessive excavation, the first interior piles may also be exposed. • The excavations will then be replaced. Using Redwood City standards, Consultant can provide a recommended approach for excavation and suitable soil replacement / compaction and repair of the surface. The likely replacement material will be a controlled low strength material (controlled density fill). • Consultant will review the borings made during original construction to establish soil layering and bounds for soil properties. This will be supplemented by a geophysical test (non-destructive) at each site to establish slow-strain shear wave speeds for the site. • Consultant will pertorm tank — pile soil-structure interaction analyses to establish the dynamic response of the tanks under three seismic ground motions (Loma Prieta, 475-year and 2/3 x 2,475 year) for the two tank sites. . Consultant will evaluate the likely ductility demands in the pile / pile-cap connections under the Loma Prieta and the design basis ground motions. . Consultant will develop recommendations as to the seismic performance of each tank under design-basis earthquakes, and any upgrades / operational changes that are suitable. The upgrades might include: do nothing; structural improvement (new caissons) to strengthen the overall tank-pile system; lower water operating levels to reduce seismic forces; soil remediation. . Consultant will write a report that includes all findings and recommendations. Consultant will submit the report as draft, meet with Redwood City ad obtain comments, and issue as final. Should the recommendations include seismic upgrades, Consultant can then provide Redwood City with the design services to implement these upgrades. The cost of these services is not included in the base scope of this proposal. Depending on the findings, the upgrades could range from operational only (install suitable instrumentation and controls to limit operational water heights); or structural (new caissons); requiring from between 2 to 10 sheets per tank. Task 5 Bid Period Services (Optional) Consultant shall assist Redwood City staff with the application processes to obtain permits as needed. For each package to be separately bid (assumed 3) Consultant shall attend a pre-bid conference for potential bidders and respond to questions and requests for information from Contractors during the bid period. Consultant shall notify Redwood City of any potentially significant questions and requests for information. ATTY/AGR/2012.001/G&E ENGINEERING Page 24 of 30 REV:Ot/10/12