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The following sections describe in detail the physical condition of the USTs, and pipe <br />purging, inerting, removal, and soil sampling procedures. <br />5.1 DEMOLITION AND REMOVAL OF CONCRETE AND MISCELLANEOUS <br />The USTs at the site were covered with a 6 -inch thick concrete pad. Prior to excavation <br />of the USTs, the concrete pad was demolished from 4 June 2001 to 6 June 2001. The concrete <br />slab was demolished using a backhoe with a breaker attachment. The concrete was stockpiled at <br />the site staging area and subsequently disposed of at a recycling facility. <br />5.2 USTS EXCAVATION AND SOIL STOCKPILING <br />Excavation was performed using a tracked excavator. Soil from above and pea -gravel <br />from below and around the tanks and pipelines were screened in the field with a photoionization <br />detector (PID) and by visual observation. The soil and pea -gravel were stored and maintained on <br />10 mil. high density polyethylene (HDPE) sheeting. <br />Field screening with the PID was performed on freshly exposed soil in the excavation at a <br />rate of once every twenty-five buckets, or with changes in soil conditions and types. All <br />excavated soil was monitored as a potential source of airborne contamination, using a PID. <br />5.3 LISTS INERTING <br />Pipes were disconnected from the USTs and open ends of the pipes were capped. The <br />USTs and pipes were drained of all residual liquids (wastewater) and/or sludges, triple -rinsed, <br />and inerted prior to removing them. Residual liquids from the USTs were pumped to an AST <br />! prior to excavation activities. The USTs were inerted by using approximately 15 pounds of dry <br />ice per 1,000 -gallon capacity, in accordance with American Petroleum Institute (API) RP 1604 <br />