SITE INFORMATION AND CORRESPONDENCE FILE 1

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West Clay Properties January 2014 639 West Clay Street Claim No: 8542 ATTACHMENT 2: SUMMARY OF BASIC CASE INFORMATION (Conceptual Site Model) Site Location/History • This case is an active commercial petroleum fueling facility in Stockton. • The Site is bounded by Interstate 5 to the west, a parking lot to the north, a residence to the east, and a parking lot across West Clay Street to the south. • Site maps showing the location of the former USTs, monitoring wells, groundwater level contours, and benzene concentrations are provided at the end of this review summary (Advanced GeoEnvironmental, Inc., 2013). • Nature of Contaminants of Concern: Petroleum hydrocarbons only. • Source: UST system. • Date reported: May 1989. • Status of Release: USTs removed. Tank Information Tank No. Size in Contents Closed in Place/ Date Gallons Removed/Active 1 1,000 Gasoline Removed May 1990 2,3 10,000 Gasoline Removed December 1998 4 6,000 Gasoline Removed December 1998 5,6 10,000 Gasoline Active -- Receptors • GW Basin: San Joaquin Valley- Eastern San Joaquin. • Beneficial Uses: Central Valley Regional Water Quality Control Board (Regional Water Board) Basin Plan list agricultural, municipal, domestic, industrial service and process supply. • Land Use Designation: Aerial photograph available on GeoTracker indicates mixed residential and commercial land use in the vicinity of the Site. • Public Water System: Stockton East Water District. • Distance to Nearest Supply Well: According to data available in GeoTracker, there are no public supply wells regulated by the California Department of Public Health within 1,000 feet of the defined plume boundary. No other water supply wells were identified within 1,000 feet of the defined plume boundary in the files reviewed. • Distance to Nearest Surface Water: There is no identified surface water within 1,000 feet of the defined plume boundary. Geology/Hydrogeology • Stratigraphy: The Site is underlain by interbedded and intermixed sand, silt, and clay. • Maximum Sample Depth: 95 feet below ground surface (bgs). • Minimum Groundwater Depth: 13.43 feet bgs at monitoring well MW-12a. • Maximum Groundwater Depth: 16.10 feet bgs at monitoring well MW-27. • Current Average Depth to Groundwater: Approximately 15 feet bgs. • Saturated Zones(s) Studied: Approximately 13 - 140 feet bgs. • Appropriate Screen Interval: Yes, screened in multiple zones • Groundwater Flow Direction: Variable, north by northwest with an average gradient of 0.001 feet/foot (December 2012). Page 7 of 14