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In April 1990, Alton Geoscience drilled 48 exploratory soil borings in a grid pattern to characterize hydrocarbon concentrations in situ. In July and August 1990, approximately 6,100 cubic yards of soil were excavated onsite to a depth of approximately 10 fbg. To the greatest4,oe +tt, d soil was removed and properly !` seri of at t s S. The excavated area was ba _ ed with appro ►ic yar ii t ed sandy gravel (Alton Geoscrence 1990. Eight monitoring wells were installed between September 26, 1990, and May 1, 1991, to evaluate the possible impact of hydrocarbons on ground water, on- and offsite. Ground water monitoring and sampling began on a regular basis in October 1990. Chronological details are presented in Appendix B, Project Background. 2.0 FIELD METHODS AND PROCEDURES 2.1 Soil Borings and Sampling Prior to commencement of drilling activities, Well Construction Permit No. 92-0631 and Soil Boring Permit No. 92-0632 were obtained from the SJCPHS. Copies of the permits are presented in Appendix C along with a copy of the encroachment agreement with Leprino Foods for offsite drilling on their property. On April 3, 1992, Abon Geospience installed onsite ground water Monitoring Well AW-9 (B-10) to a total del#h of appy i28.5 fbg (Figure 2). Additionally, five offsite soil borings (B-11 throw& B-15) wesreT d downgradient to the north of the property in the locations shown in figure 2; two borings adjacent to the sidewalk on the north side of East Grantline Road, and three borings in the Leprino Foods parking lot. Soil borings were dri Ited u l cpgtituous-core sampler to provide optimum stratigraphic characterization and Ground water Monitoring Well AW-9 was completed using 6-inch-diameter polyvinyl chloride (PVC) casing to further assess the extent of dissolved-phase hydrocarbons in ground water, and for possible use as an extraction well in a ground water remediation program. s Downgradient Soil Borings B-11 through B-15 were drilled and sampled to further assess the presence or absence of adsorbed-phase hydrocarbons in soil north of the site on Leprino Foods property (Figure 2). The borings were each drilled to a total depth of approximately 11.5 fbg to investigate the subsurface to the capillary fringe interval. The procedures and methods used during field activities were in accordance with the requirements of the SJCPHS and the Regional Water Quality Control Board, Central Valley Region (RWQCB). Drilling and soil sampling procedures are presented in Appendix D and boring logs for this and previous studies (borings shown in Figure 2) are presented in Appendix E. 2 i.