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Contaminated soil will be transferred from the excavation areas to the staging area via a loader and placed on a 20-mil plastic liner. All soil will be covered with a plastic liner at the end of each workday. Grab samples from the contaminated soil piles, approximately 1 sample per 50 cubic yards will be analyzed for TPH diesel and hydraulic oil (C12 — C32), BTEX. and TTLC metals (cadmium, chromium, lead, nickel, and zinc) for disposal determination. Clean soil will be imported onto the site to be used to backfill the excavations to replace any soil that has been impacted. 3.7 Confirmation Sampling Confirmation sampling of the excavation faces using a field immunoassay test kit and sending soil samples to a fixed laboratory will be performed to verify that the impacted soil has been completely removed. The extent of the source removal beyond the excavation areas is dependent upon the TPH action level. Based upon the site characteristics, current use, nature of contamination, an action level of 50 ppm for TPH hydraulic oil, carbon chain C23 to C32, is deemed appropriate for this site. The cleanup level for TPH diesel, carbon chain C12 to C22 is set at 1 ppm per direction of the CV-RWQCB. Initial soil confirmation samples will be collected at bottom of the excavation, 4 feet bgs, in the excavations' center and from the center of each sidewall at 2 feet bgs. The field immunoassay test kit will be utilized to confirm that all impacted soil above the TPH action level has been removed. Approximately 10 samples will be analyzed using the field test kit; five from Excavation 41 and five from Excavation #2. The sampling locations are depicted in Figures 6 and 7 respectively. If any of the soil screening samples exceed the 50 ppm action level for hydraulic oil, then the excavation will be continued and additional soil samples tested until all Rough& Ready Island 19 Tetra Tech, Inc. Revised Draft Work Plan November 18, 1998