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A retaining wall with a pile foundation is required at this location. We will need to design a special wall supported on piles. This requires that we prepare design calculations and a detailed design sheet for the retaining wall as opposed to referencing a standard plan sheet. The ground water table is quite shallow in this area due to the presence of the drainage channel which runs along the south side of the freeway. Since the drilling for the retaining wall support piles will extend below this water table ground water will be discharged during the drilling operation and construction of the piles. In this situation Caltrans requires that the ground water be sampled during the design phase of the project and tested for water quality purposes to determine if the ground water can be discharged to the drainage system or must be treated before disposal. Additional ADL Testing In March 2011 Geocon submitted a work plan to Caltrans for approval prior to beginning the field sampling and ADL work. Caltrans has reviewed our proposed work plan and is requiring an additional 5 borings for the ADL. analysis. I have attached a copy of the scope and fee for Geocon to perform the additional ADL testing and the ground water sampling and testing for water quality purposes as noted above. Additional Traffic Forecasting At the May 10 2011 meeting with Caltrans, Caltrans staff indicated that the Project Report for the interchange improvements was approved 10 years ago and the traffic forecasts presented in the Project Report were for the year 2025. Caltrans and FHWA staffs are requiring that updated traffic forecasts be prepared for the year 2035 using the most recent regional land use projections as required Caltrans and FHWA project development procedures. I have attached a copy of the scope and fee for Fehr and Peers to perform the additional traffic forecast for year 2035. Update Natural Environment Study (NES) Report At the June 29, 2011 environmental meeting with Caltrans, Caltrans staff indicated that the NES for the interchange improvements was approved 10 years ago. Caltrans staff is requiring that the NES be updated as part of the environmental revalidation process for the project. David Powers will prepare the NES Addendum. The NES Addendum will document the latest field review of the project site and the current special status species information. The budget for this task of work is based on our research and field review conducted on July 8, 2011, and the assumption that special status species are not present within the project footprint.