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Phase II Environmental Site Assessment Report- Executive Summary 206 Sutter Street APN 139-250-030 Page ii Analytical results from soil samples collected from DP-1 at 35 feet bgs indicate elevated concentrations of TPH-D, TPH-G, and TPH-MO at 8,000 milligram per kilogram (mg/kg), which is above the U.S. Environmental Protection Agency’s Regional Screening Levels (US EPA RSL) for industrial soil of 560 mg/kg, 20,000 mg/kg, and 540 mg/kg, which is also above the US EPA RSL for industrial soil, respectively. TPH-D and TPH-MO concentrations significantly decrease at 45 feet bgs. TPH-G decreases to 330 mg/kg in the soil sample collected at 45 feet bgs and 3.3 mg/kg at 55 feet bgs. Photoionization detector (PID) readings collected during soil sampling at DP-1 indicated measured concentrations of 15 ppm at 10 feet bgs; 5.0 ppm and lower from 15-30 feet bgs; from 50 ppm to approximately 200 ppm at 30-45 feet bgs; and from 5 ppm to 13 ppm at 45-60 feet bgs with the associated dark blue color staining. Petroleum odors were observed by field personnel in the field with samples associated with elevated PID readings. In the eastern portion of the Site, no contamination was observed or documented with the exception of TPH-MO in the groundwater sample collected at DP-7, which was detected at 510 µg/L, just above the laboratory reporting limit of 500 µg/L. No staining was observed and the PID measured 0.0 ppm throughout the entire boring. Soil and groundwater contamination appears to be confined in the southwest and western portions of the Site where the historic fueling station was located prior to construction and demolition of the Ambassador Hotel with at least 20 feet of separation between the ground surface and the contamination plume in the subsurface. Shallow groundwater in Stockton is not used for public consumption or use; therefore, it is Condor’s opinion that the contamination plume does not pose a material risk to human health at the Site and does not likely pose a vapor encroachment concern for the Site. As a result, it is Condor’s opinion that the planned construction of a parking lot is the best land use for redevelopment of the Site. Condor recommends the development of a groundwater monitoring well network to obtain groundwater quality data over four (4) consecutive quarters to confirm concentrations as well as the extent of the past release in the direction of groundwater flow (northeast). LIMITATIONS TO EXECUTIVE SUMMARY This executive summary should only be read as a brief summary, and not as a complete discussion of the full report text. The scope of work and limitations should be understood prior to reading the Site- specific information, results, and discussion.