SITE INFORMATION AND CORRESPONDENCE

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r Former LTS Rentals - 2 - 24 July 2012 1430 and 1600 South Cherokee Lane, Lodi SITE INVESTIGATION Recommendations in a 2003 Phase I Site Assessment (PSA) included the proposed removal of a set of six ASTs and fuel dispensers, an underground vapor recovery tank associated with the AST system, and a truck wash rack with an underground clarifier. The PSA also recommended a site investigation to assess whether soil had been impacted (see Figure 2 for site features). In June and September 2003, Advanced GeoEnvironmental (AGE) collected soil samples from exploratory trenches to locate impacted soil surrounding the AST locations (see Figure 3 for trench sample locations and Table 1 for soil analytical results). AGE detected total petroleum hydrocarbons as diesel (TPHd) at a maximum concentration of 6,400 milligrams per kilogram (mg/kg), and traces of ethylbenzene, xylenes, polycyclic aromatic hydrocarbons (PAHs), and lead. In 2005, five soil borings (SB-1 through SB-5) were drilled and sampled in the former AST containment area (see Figure 3 for boring locations and Table 1 for soil analytical results). Soil encountered during drilling at the site consisted of silt from the ground surface to 10-15 feet below the ground surface (bgs). Beneath this surficial unit, interbedded sands, silts and clays were present to total depth. Poorly-graded sands and silty sands are the predominant soils. Groundwater samples were collected from SB-1 through SB-4 at 55 feet bgs (see Table 2 for results). Analytical results for all groundwater samples were non-detect for total petroleum hydrocarbons as diesel (TPHd), total petroleum hydrocarbons as gasoline (TPHg), BTEX and fuel oxygenates including MtBE. Regional groundwater flow is toward the south-southeast. However at a nearby fuel leak investigation site, groundwater flow is toward the northwest. REMEDIATION In their 22 October 2009 work plan, Ground Zero proposed the removal of hydrocarbon impacted soil that was identified in the vicinity of the former ASTs and the investigation and removal of any hydrocarbon impacted soil that may be associated.with the former fuel dispenser area. There was no hydrocarbon impacts associated with the clarifier or underground vapor recovery tank. Remediation activities performed by Ground Zero at the site included the excavation of overburden and petroleum impacted soil; segregating and stockpiling soil; and sampling of both the overburden and petroleum impacted soil stockpiles. The first phase of excavation activities occurred in November and December of 2009. An area of approximately 5,500 square feet was excavated beneath the former AST containment area and beneath the former pump island. Petroleum impacted soil was encountered in the northeast corner of the former AST containment area (see Figure 4 for excavation limits) vertically between 15 and 38 feet bgs. Approximately 3,800 cubic yards of impacted soil was stockpiled on asphalt pavement northeast of the excavation. Following