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Task 2: Installation of Two shallow Ground-Water Monitoring Wells <br /> Permits for monitoring well installation will be obtained from <br /> the San Joaquin Local Health District prior to the start of work. <br /> Drilling and installation of the two monitoring wells will be <br /> performed by Spectrum Exploration, Inc. , holder of a C-57 <br /> license, of Stockton, California. The monitoring wells will be <br /> drilled using the hollow-stem auger drilling method. The actual <br /> depths of the monitoring wells are anticipated to be <br /> approximately 22 to 25 feet below the ground surface, which is <br /> consistent with the depths of wells previouslyinstalled in that <br /> area (LF-6 through LF-9) . The proposed locations of the <br /> monitoring wells are shown on Figure 2. one monitoring well will <br /> be installed approximately to to 15 feet northwest of the former <br /> location of Tank 1 (Figure 2) . The second well will be located <br /> in the northwest corner of the Tank 2 excavation area (Figure 2) , <br /> due to its proximity to the garage directly northwest of this <br /> location. <br /> Soil samples will be collected near-continuously from each of the <br /> well borings for lithologic description. one soil sample will be <br /> retained from each boring for analysis of fuel hydrocarbons. <br /> Samples for chemical analysis will be collected in clean brass <br /> liners using a Modified California sampler. These samples will <br /> be immediately sealed and placed in chilled coolers for <br /> transportation to the laboratory. <br /> Each monitoring well will be constructed ochdiamtecasing. <br /> flush threaded, polyvinyl chloride (PVC) , factory-slotted <br /> The well annulus outside the perforated interval will be back- <br /> filled with an appropriately sized sand pack. Bentonite pellets <br /> and a cement-bentonite slurry will be placed above the sand pack <br /> to the ground surface to seal the annular space of the borehole. <br /> A protective, locking steel cover or Christy box will then be <br /> placed over the top of each well. <br /> The elevation of each well will be surveyed by a licensed <br /> nd tied <br /> surveyor to taetemporarynearest obenchmark. 01 foot ato allow accurate existingo an <br /> accuratemeasurement <br /> benchmark or P <br /> of the ground-water elevation. <br /> Before use in each well or borehole, drilling and sampling <br /> aterials will be cleaned using high-pressure <br /> equipment and well m <br /> hot water (steam-cleaned) . Power, water and an area for cleaning <br /> equipment are to be provided at the Site. <br /> 4 <br />