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Once the excavation was cleaned out to the depth of 25 feet bgs, samples P25W, P25E, P25S,
<br />P25N and P25B were collected The sample identification numbers correspond as follows, P
<br />' = Pit, 25 = 25 feet bgs, N, S, E, W = North, South, East West and B = Bottom The
<br />analytical results from the onsite mobile laboratory for all samples collected and analyzed on
<br />March 9, 1993 are enclosed on Table 1
<br />Based on the excavation samples collected on March 9, 1993, the excavation was expanded in
<br />the north and east directions and the total depth was increased. After removing the first lift of
<br />this expanded excavation, samples P -BW, P -BE and P -El were collected from the west side of
<br />the excavation bottom, the east side of the excavation bottom, and the excavation east wall
<br />respectively The north wall of the excavation was then cut back an additional 2 feet and soil
<br />samples NW -1E and NW -1W were collected Upon receipt of the analytical results for these
<br />samples, the total depth of the excavation was increased to approximately 30 feet bgs and the
<br />northeast side of the north wall and the east wall were cut back an additional 2 feet Samples
<br />P-NE2, P -E2 and P-BE2 were then collected All of the analytical results for the soil samples
<br />collected and analyzed on March 10, 1993 are contained on Table 2.
<br />On March 11, 1993, an additional 1 foot of soil was removed from the north and east walls of
<br />' the excavation Samples P -E3 and P-NE3 were collected Based on the results from these
<br />samples, as shown on Table 3, the excavation was cleaned out and confirmation samples P -S4,
<br />' P -W4, P -E4, P --N4, P-BW4 and P-BE4 were collected While these samples were being
<br />analyzed, transport trucks from Remco, a soil recycling facility, arrived on-site to remove the
<br />stockpiled soils containing petroleum carbon residues For March 11, 1993, eleven truckloads
<br />of soil were transported to Remco's Richmond California yard for recycling and use in road
<br />base
<br />Upon receipt of the analytical results for the six confirmation soil samples, it was decided to
<br />expand the excavation further in all directions. Once expanded, samples P-NE5, P-NW5, P-
<br />BW5, P -S5 and P-BE5 were collected from the excavation area Based on the results from these
<br />samples, the north and east walls of the excavation were expanded further and the total depth
<br />was increased to approximately 32 feet bgs Samples P-BE6 and P-BW6 were then collected
<br />and analyzed
<br />Since the analytical results indicated near complete compound residual removal and since the
<br />physical limits of the excavation were being approached, it was decided to collect final
<br />' confirmation samples
<br />At the direction of the EHD personnel, twelve soil samples were collected from various locations
<br />and depths within the excavation Each of the sample identification numbers correspond to the
<br />' directional wall or bottom, depth and, for the north wall samples, corresponding side direction
<br />For example, P-N30W is a north wall sample (N), collected at a depth of 30 feet bgs (30) from
<br />the west portion (W), while P-BW6 would be a bottom sample (B), west side (W) The
<br />' approximate locations from which these samples were collected and the total extent of the
<br />excavation are shown on Figures C-3 and C-4 For Figure C-4, the "P" was removed from the
<br />sample designation for clarity sake Only samples P-N20W, P-N30E and P-N23C were analyzed
<br />by the on-site laboratory The remaining undisturbed volume for these samples, along with the
<br />other nine unopened samples, were transported to WESTON's Stockton Analytical Laboratory
<br />for expedited analyses utilizing the purge trap sample preparation Method 5030 All of the
<br />' analytical results from the on-site mobile laboratory are included in Appendix D
<br />C - A 051171/3
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