ARCHIVED REPORTS_PHASE II ENVIRONMENTAL SITE ASSESSMENT

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W GI, • Soiuithwve s t, Inc. The USDA has classified this component as "Class C" based on hydrologic conditions, indicating soils with slow infiltration rates, containing layers that impede the downward flow of water with moderately fine or fine textures. This is consistent with the clayey soils that were encountered during the Phase II field investigation. The USDA classifies the soils as having moderate corrosion potential and pH values ranging from 5.10 to 6.50. During this investigation soils encountered on the site consisted primarily of low to medium plasticity silty clays and clayey silts. Occasional interbedded layers of poorly graded clayey fine sands were noted in some borings typically below about 12 feet. The soils observed during the investigation were consistent with the Yellowlark component identified by the USDA SCS. 6.3 Groundwater Conditions Groundwater flow direction in the area is variable due to influences produced by the proximity of the deep water channel on the north and the San Joaquin River on the west and southwest. In general, recharge from these surface waters exerts hydrostatic pressure on the shallow groundwater resulting in a gradient away from the river and channel. This would • suggest a groundwater flow direction toward the east or northeast might be expected on site. However, previous groundwater monitoring conducted on the Learner site during 2003 determined the groundwater flow direction to be toward the southeast at a gradient ranging from 0.005 to 0.009. At that time, the depth to groundwater was recorded to range from approximately 7 to 12 feet below surface grade of the site. During the Phase II field investigation, saturated zones were noted in the subsurface soils within most of the borings beginning at approximately 9 to 12 feet below ground surface (bgs). After the borings were allowed to recharge, groundwater rose to approximately 8 to 9 feet bgs in most of the borings. 7.0 PRE-FIELD ACTIVITIES 7.1 Permitting A permit was obtained from the SJCEHD for the 18 soil borings. The work was conducted under SJCEHD permit #0053008. SJCEHD also required a Master File Record (MFR) information form for the site be filed prior to issuance of the permit. A work plan, dated December 12, 2007, was prepared by WGR and submitted to SJCEHD on behalf of The Port in accordance with the application requirements for a permit to drill. The work plan was approved by SJCEHD with no modifications or stipulations. • 704. PRI.05 15 July 21, 2008