SITE INFORMATION AND CORRESPONDENCE

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River City Petroleum -2 - 15 April 2014 Connell Motor Lift Truck 2211 North Wilson Way Stockton, San Joaquin County not note any leakage from the waste oil USTs. At that time the waste oil USTs were exempted from SJCEHD permits due to their location in a concrete vault. In 1998, when SJCEHD discovered the lube bay filled with concrete, staff interviewed the owner of the tanks, Kerry Heckman, who could not remember the date when the waste oil tanks were removed nor give the fate of the waste oil tanks. A diesel spill was reported in September 1997 at RCP dispenser island No. 2. At that time, the San Joaquin County Environmental Health Department (SJCEHD) inspector noted the concrete slab was deteriorating at the dispensers, visible staining was present in exposed soil, and further investigation was requested. On 28 October 1997, the SJCEHD issued an Unauthorized Release Form and opened a USTs case, naming RCP as the responsible party for the release of petroleum fuels. In February 1998, the SJCEHD discovered the gasoline vapor recovery system was inoperative, and RCP was required to suspend gasoline sales pending repairs. In March 1998, the RCP fueling station was permanently closed. In June 1998, the two 10,000-gallon gasoline and one 10,000-gallon diesel USTs, installed in October 1986, by RCP were removed by Connell. Results of confirmation soil samples taken at the time of tank removal reported no detectable fuel hydrocarbons (TPHd by Method 3550 LUFT and TPHg by Method 5030/LUFT) at a detection limit of 1 mg/kg and benzene-toluene-ethylbenzene-xylenes by Method 8020 at a detection limit of 5 micrograms/kg in the tanks pit. High levels of petroleum hydrocarbons were reported as visible under the dispenser islands and near old piping not removed during the prior USTs removal in 1986. According to the USTs removal report prepared by Foothills Engineering for Connell, less than 50% of the planned dispenser excavation occurred when work was halted, due to the large area of visible contamination noted in the soil. Confirmation soil samples collected in the area of the dispensers showed elevated levels of petroleum hydrocarbons in soil (see Table 1 below). Approximately 200 yds3 of soil was over-excavated in October 1998 and stockpiled onsite. No post excavation soil samples were collected. The stockpiled soil was stored onsite until 18 February 2014, when drill cuttings and stockpiles were transported and properly disposed at Forward Landfill in Manteca. Table 1A Maximum RCP soil investigations concentrations given in milligrams per kilogram (mg/kg) from -remediation investi ations , Date TPHg TPHd -FPHss B T E X MTBE 1,2-DCA Pb EDB 6-98' 19 7,500 NA <0.025 0.035 0.52 0.28 <0.010 NA NA NA 12-981 3,670 7,680 NA <0.6 0.56 3.58 65.9 NA NA NA NA 9-99 4,710 6,240 NA 17.6 105 31.9 239 0.32 NA NA NA 9-00 27,500 15 NA 31 945 263 1,610 NA NA NA NA 8-02 738 ND NA ND 1840 2030 8,440 ND ND 6 NA 5-03 1,600 NA NA 3.5 8.3 8 110 ND 55 NA NA 4-04 9,400 NA NA 58 410 180 870 <500 860 NA 660 1-07 2,900 NA NA 24 56 28 190 NA <0.05 NA NA 2-07 680 NA NA 6.4 18 7.8 98 _ TPHg= total petroleum hydrocarbons as gasoline TPHd= as diesel TPHss = as Stoddard Solvent= benzene I — toluene E = ethylbenzene X = xylenes MTBE = methyl tett butyl ether Pb = total lead EDB = ethylene dibromide NA = not analyzed ND non- detect 1 = confirmation soil samples Three shallow RCP monitoring wells (MW-1 through MW-3) were installed in September 1999. Three additional shallow RCP wells (MW-4 through MW-6) and four deep monitoring wells (MW-7 through MW- 10) were installed in September 2000. Maximum RCP groundwater results are listed in Table 2A below.