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can be from disturbed samples and will be delivered for testing within two days after the samples are collected. No pavement analysis will be performed on the mainline road or other sites on US101 that are unchanged due to this project. It is assumed a pavement deflection study is not required. Specifically, the Materials Report will include: A. Review of boring logs and preliminary plans for bridge structure location and depths. B. Measure soil resistivity using the Wenner 4 -electrode method at 12 locations for the proposed bridge structures and retaining wall structure for the Foundation Reports and Materials Reports. The Wenner 4 -electrode method provides in-situ soil resistance data at various depths at the locations of the project construction. Calculate Bames Layer soil resistivity at depths of 2.5, 5, 7.5, 10 and 15 feet below grade for the retaining walls and infill walls and 2.5, 5, 7.5, 10, 15, 25, 50, 75 and 100 feet below grade for the bridge and overcrossing locations. C. Perform soil box resistivity analysis on soil samples to be provided by the project geotechnical engineer. Up to 20 soil samples will be analyzed. The 20 samples will be sent to an independent laboratory for chemical analysis. Samples will be analyzed for pH, water soluble chlorides, water soluble sulfates, and bicarbonates. The results of the chemical analysis with respect to conosivity of buried metallic structures and buried reinforced concrete structures will be evaluated. The analysis will be in accordance with the applicable Caltrans Test Methods. D. Prepare corrosion assessment reports in accordance with Caltrans Corrosion Guidelines (January 2015) with the results of the field resistivity testing and the laboratory chemical analysis. The degree of corrosivity of the soil will be discussed. Recommendations will be made for corrosion control of buried reinforced concrete structures. 7. Project Hazardous Materials Test Report AECOM conducted the Initial Site Assessment (ISA) for this Project for the City and Caltrans in the fall of 2014. AECOM will implement a soil and limited groundwater investigation in the existing Caltrans right-of-way that is focused on the contaminant issues specific to the portion of the Project to be investigated, as identified in the ISA as follows: • Metals including Aerially Deposited Lead (ADL) from the former combustion of leaded gasoline. • Petroleum hydrocarbons from leaking Underground Storage Tanks (USTs) as gasoline and diesel. • Chlorinated hydrocarbons including solvents typically used as degreasers and dry cleaning chemicals. • Polychlorinated Biphenyls (PCBs). The purpose of the investigation will be to identify site contaminant concentrations that will require management and or mitigation measures, as follows: Page 22 of 73 REV: 07-18-17 PR ATTY/AGR.2017.166/AECOM 101/84 PS&E