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Mr.Nuel Henderson Page 2 of 3 Drilling and Well Construction A 12 1/4-inch diameter boring will be drilled with mud rotary equipment to a depth of approximately 90-95 feet bgs at which point a clay bed should be present. Drilling mud will be kept in a slightly overbalanced condition in order to minimize fluid entry into the wellbore. 6 5/8-inch diameter welded steel conductor casing led by a grouting shoe will be set in the clay bed for grouting. Three equally spaced centralizers will be installed on the casing to ensure a uniform thickness of annular seal and to prevent cement channeling. The conductor casing will be grouted through the shoe with Class II neat cement, which will be circulated through the annulus to the surface and allowed to cure for a period of approximately 72 hours. After the cement has cured, the grout shoe will be drilled out and a 6-inch diameter boring will be advanced to a depth of approximately 120 feet bgs using mud rotary equipment. Drilling mud will be changed after drilling out the shoe and will be kept in an overbalanced condition to minimize fluid entry and to control possible heaving sands. To complete the well, 2-inch diameter PVC casing equipped with centralizers and 10 feet of 0.020 slot pre-packed screen will be set from the bottom of the boring to grade. The screened interval will be from approximately 105-115 feet or 110-120 feet bgs, depending upon the lithology encountered during drilling. Approximately 2 additional feet of filter pack will be placed above the pre-packed screen. The remaining annulus will be completed with 2 feet of bentonite overlain by neat cement grout to the surface emplaced with a tremmie system. At the surface, the well will be fitted with a locking cap and water tight, traffic rated well box. A well construction diagram for MW 17C is shown on Figure 3. Due to the mud rotary drilling method, we do not expect to collect undisturbed soil samples for laboratory analysis. The lithology of the soil units penetrated in the boring will be determined by logging the drill cuttings. Drill cuttings and drilling mud will be stored in lined rolloff bins pending disposal. Water generated from equipment decontamination, well development and sampling will be contained in labeled DOT approved drums. All waste will be stored on site pending laboratory results and the development of disposal options. Surveying, Well Development and Groundwater Sampling and Analysis The elevation of the casing collar of the new well will be surveyed to a vertical accuracy of 0.01 feet and the latitude and longitude of the well will be established to an accuracy of one meter or less. A minimum of 48 Ins after well completion, an experienced field technician will measure static depth to water and then develop the well by pumping and surging until turbidity is minimized and measurements of pH, temperature, and electrical conductivity have stabilized. A minimum of three casing volumes will be purged from the well. Subsequent to well development, groundwater samples will be collected after water levels have recharged to at least 80% of the static levels. Water samples will be placed in appropriate G:\GROUNDZE\ROEK\CLOSURE\Workpia\MW17CWorkplm,doc