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t o Work Plan to Perform Subsurf3Ce Investigation • BASI 01-09-002-CA Sutter Orchard December 10, 2009 Page 2 of 3 Geologic and Hvdrogeologic Setting The subject property is located in the Central Valley of California. The valley is a southern extension of the California Great Valley Province, a broad asymmetric trough filled with a thick assemblage of flat-lying marine and non-marine sediments derived from the Sierra Nevada foothills and mountains on the east side of the valley and from the Inner Coastal Range on the west side of the valley. Based on a review of the USGS Clements Quadrangle Topographic Map, the Sutter orchard parcel is situated approximately 75 to 125 feet above mean seas level with a topographic gradient that slopes to the northwest. Site-specific groundwater information was unavailable for the subject Property. According to information obtained from AEI's Phase I ESA, the depth to regional groundwater ranges from approximately 70 to 90 feet below ground surface (bgs). Based on regional surface topography, the groundwater flow direction is inferred to be toward the northwest. Proposed Scope of Work The proposed work described in this work plan is intended to assess the presence or absence of petroleum hydrocarbons in soil beneath the three former UST excavations. Prior to initiation of the field work, ADR will notify underground utility locating services, contract with a licensed driller and state certified laboratory, acquire drilling permits from San Joaquin County Environmental Health Department (EHD), and schedule field activities. Fieldwork will be conducted in accordance with the drilling and sampling methods described in Attachment A. A site specific Health and Safety Plan, designed to minimize exposure of the orchard workers and subcontractors to potentially hazardous wastes and injury, is presented in Attachment B. Subsurface Assessment Using track-mounted direct push drilling methods, ADR proposes to advance six soil borings within the subject Property to a depth of 12 feet bgs. More specifically, as shown in Figure 2, ADR will advance two soil borings in the vicinity of each former UST excavation (one boring at each end of the feature). Each of the soil borings will be advanced under the supervision of a C-57 licensed water well driller. Direct push soil samples will be collected from each boring at 5 foot or less vertical intervals beginning at 5 feet bgs. Recovered soil samples will be properly logged, documented on a chain-of-custody form, and field screened for organic vapors using a photoionization detector (PID). Soil samples collected will be placed on ice and transported to a California certified laboratory under proper chain-of- custody procedures for laboratory analysis. After collection of the soil samples, each borehole will be abandoned by filling with a neat cement slurry. The surface will be patched as necessary to match the surrounding surface materials. Laboratory Analysis Selected soil samples (at least one per boring) will be submitted for laboratory analysis of total petroleum hydrocarbons as gasoline (TPHg), diesel (TPHd), and kerosene (TPHk) by EPA method 8015 modified and/or benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8021.