SITE INFORMATION AND CORRESPONDENCE

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3.2 PREPARATION 3.2.1 Decontamination The drill rig, drill rods, drill bits, augers, temporary casing, well developing equipment, tremie pipes, grout pumping lines, and other associated equipment shall be cleaned with high-pressure hot water/steam prior to drilling at each monitoring well location, and before demobilization. Decontamination shall be done in accordance with ASTM D-5088. Equipment, tools, and supplies shall be placed on racks, saw-horses, or plastic sheeting to avoid contact with the ground. Decontamination shall be performed in accordance to paragraph 3.2.2 at a central decontamination station. The decontamination station will be designated by Tracy DD IEC. Screen and well casing shall be cleaned with high-pressure hot water immediately prior to installation in the well. The use of factory sealed(plastic wrapped) screen and well casing does not waive this requirement for pre-installation cleaning. Samplers, for soil sampling, can be alternatively cleaned by washing with a non-phosphate detergent, a tap water rinse, and a DI water rinse. Tracy DD has a non-chlorinated water source which will be used for all decontamination procedures during this project (see paragraph 3.2.3). 3.2.2 Decontamination Station The Contractor shall construct a temporary decontamination pad onsite. The pad shall be bermed and slightly inclined towards a sump located in one of the back comers of the pad. Plastic sheeting shall line the pads and berms to contain decontamination water. Plywood sheeting, exterior grade, shall be placed over the plastic sheeting to prevent damage to the plastic and allow the drill rig and heavy equipment to use the pad. The minimum dimensions of the pad shall be the length and width of the drill rig,plus 4 feet per side to allow access and steam cleaning. Yellow ribbon shall be used to encircle the decontamination pad. Water collected in the sump shall be pumped using a "trash" pump to transfer water to a 55 gallon drum labeled 'Decontamination Pad Sump Water." Solid waste shall be transferred to a separate 55 gallon drum labeled "Decontamination Pad Sump Sludge." 3.2.3 Water Source Water for decontamination and water for well drilling/installation, if required, shall be from a designated source on base. Non-chlorinated water,provided by the base, shall be used for all decontamination and drilling procedures. The Contractor shall provide a clean container for storage of the water until it is to be used. The Contractor shall be responsible for obtaining the water from the source, transporting it to and storing it at the site. 3.3 INSTALLATION Two (2) new monitoring wells will be drilled and installed under this contract, one shallow and one deep. Locations of the new monitoring wells will be coordinated with the IEC. Specific 02671-005