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• and associated piping at the site will be located using electronic locating equipment and by correlating site reconnaissance and the supplied as-builts drawings of the UST area. Tank and piping location will be evaluated to determine what measures, if any, are to taken to prevent damage to existing utilities. Underground Services Alert (USA) will be notified at least 48 hours in advance to check utilities. The tank location, dimensions, and ancillary equipment will be identified by using marking paint. Any underground utilities not associated with the tank will be identified by USA using marking paint of a different color. Mobilization of field equipment and supplies will be done following the site reconnaissance. C3.2 Task 2 - Exposure of Tank and Piping Before excavation starts, the surface area above the tank will be cleared of asphalt pavement and any surface debris. The tank will be exposed using a track-mounted excavator or wheeled backhoe until sufficient area is available for purging and inerting the tank. All piping will be similarly uncovered until sufficiently exposed to allow removal of the piping. C3.3 Task 3 - Removal and Disposal of Piping and Contents • There are approximately 100 linear feet of underground fuel lines beneath the asphalt pavement. These pipes will be located using an electronic locating equipment. Following exposure, the exposed piping will be gravity drained into the tank by lifting the piping section farthest from the tank first and draining any liquids in the farthest section to sections of piping closer to the tank. Draining will proceed by lifting sections of the piping closer and closer to the tank. The drained pipeline liquids will be removed from the tanks by a vacuum truck. The piping will then be flushed with water from a high pressure washer and drained in the same manner as described above. The piping will then be disassembled at the joints. Welded pipe will be cold-cut using an air-operated pneumatic saw. Cutting will be performed after the piping has been flushed and inerted. Water will be sprayed over the area of pipe being cut to prevent heat buildup and sparking. Upon removal, the piping and soil beneath the piping will be inspected for signs of leakage. The inspection will be documented in the field logbook and in photographs. The COR will be notified if at any time during piping removal a leak is identified. If visual inspection of the piping indicates that the integrity of the piping may be suspect, the flushing will take place in a 30 foot by 10 foot bermed area. The flushing area, located within the exclusion zone, will be lined with 20 mil plastic sheathing. The atmosphere in the pipe will be monitored for combustible vapors using an • explosimeter, which is calibrated against methane. The explosimeter probe will be inserted into the ends of the piping without touching the walls of the piping. The piping will be flushed until the flammable vapor concentration is less than 10% of the lower explosion C-4