SITE INFORMATION AND CORRESPONDENCE

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Quick-N-Save #1 . 2 - September 2012 Claim No . 14840 ATTACHMENT SUMMARY OF BASIC SITE INFORMATION (Conceptual Site Model ) Site Location/ History • The Site is located at 1901 South EI Dorado Street in Stockton , California and is an active retail gasoline station . • The Site is bounded by a residence to the west, West 5t' Street to the north , South EI Dorado Street to the east and a residence to the south . The surrounding land use is mixed residential and commercial . • In December 1999, soil contamination was identified during the removal of USTs . • To date, ten monitoring wells have been installed and monitored regularly. • A Site map showing the location of the current USTs, monitoring wells and groundwater level contours is provided at the end of this five year summary. Pollutant Source • Nature of Contaminants of Concern : Petroleum hydrocarbons only . • Source, Date reported , and Status of Release : UST system , 7 December 1999 , USTs replaced . • Free Phase Hydrocarbons: None reported . Geology/ Hydrogeology Stratigraphy: The Site is underlain by interbedded and intermixed sand , silt and clay. Maximum Sample Depth : 105 feet below ground surface (bgs). • Minimum Groundwater Depth : 20. 43 feet bgs at monitoring well MW-5 . • Maximum Groundwater Depth : 32 . 20 feet bgs at monitoring well MW-1 . • Current Average Depth to Groundwater: 22 feet bgs . Saturated Zones (s) Studied : 21 to 105 bgs . Groundwater Flow Direction : Variable , shallow is generally southeast at 0 . 004 feet per foot and intermediate is northeast at 0 . 001 feet per foot. Groundwater Trends : This Site has been monitored regularly since 2004. Benzene trends are shown below: Shallow source area (MW-3) and Intermediate depth down gradient (MW-5) . BENZENE Results for MW3 _- - 5000 45000 —- - — 40000 '--- - — - 35000 - - - — - � 30000 - - - -'j25000 20000 1 .000 r1 100001 { -- -- - - - 5000 ]-- --/ �i 0 �t — �—BENZENE Trend j