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2. SCOPE OF WORK To identify and characterize any possible agricultural chemical residues at the Site, CRA proposes to collect a maximum of nineteen naturally occurring surface soil samples and nineteen naturally occurring shallow soil samples. These samples will be collected from the locations shown on Figure 2 and will be collected from the natural Site surface which resides directly beneath the stockpiled soils. Additionally, selected soil samples will be collected from the stockpiled soils (also shown on Figure 2). The sample collection matrix is presented on Table 1. The sample locations were selected by overlaying the Site with a one- acre grid system and selecting two sample collection locations within each of the one-acre grids (on half acre centers as recommended in the June 2000 DTSC Agricultural Sampling Guidelines for Grammar Schools located on two to twenty acre sites). Three additional sampling locations were selected from the remaining southern portion (one and one-half acres) of the Site. Samples will be collected from the locations within each grid to make up discrete and composite samples as discussed below. Since the entire regional area, including the Site, had once been part of similar, much larger size farming operation, it is assumed that all operations and applications occurred over the region uniformly. Therefore, a grid system smaller than the one presented is not warranted. The following sections describe the proposed sample collection techniques and laboratory analyses. All activities described in this scope of work will be conducted under the direct supervision of a California Registered Geologist (RG) and/or a Registered Environmental Assessor II (REAII) 2.1 SOIL SAMPLE COLLECTION Soil sample collection activities will be conducted utilizing direct push (Geoprobe) sample technology. Prior to soil sample collection, CRA personnel will lay out the one- acre sampling grid and the sample collection locations will be marked. The soil samples will be collected from each of the two discrete locations within the one-acre grid at depths of 0 to 1 foot beneath the natural ground surface (bgs) and from 2 to 3 feet bgs into natural ground (beneath the natural ground/stockpiled soil boundary). Additional discrete soil samples will be collected from selected zones within the overlying stockpiled soil. The individual sampling locations (on top of the soil stockpile surface) will be surveyed from existing benchmark locations and assigned an elevation. The natural ground surface at each sampling location will be determined from a Site topological map prepared prior to the stockpiling of the storm water retention pond soils; the natural ground surface will then be confirmed by identifying the natural ground/base of the stockpile boundary. The identification of the natural ground 031090-10(3) -2- CON ESTOGA-ROVERS&ASSOCIATES