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<br />. <br /> <br />. <br /> <br />areas. At this time no drilling is anticipated within the reservoirs to <br />evaluate the suitability of the reservoir to hold water. However, if <br />surficial geologic mapping indicates any unusual conditions, additional <br />boreholes will be added to the program for exploration within the reservoir. <br />The exploration at Lake Avery will be different from the others and is <br />covered at the end of this task definition. <br /> <br />Subsurface investigations shall be made by boreholes, test pits, and <br />geophysical methods. A specific program shall be prepared for each site. <br />The drilling shall be tailored to obtain the maximum amount of information <br />within the limits of total length of drilling outlined herein. For the <br />entire upper portion of the borehole which is not in sound rock, the <br />drilling shall be four-inch diameter, cased rotary/percussion type. The <br />casing advancer technique shall be employed to enable "in situ" tests and <br />recovery of undisturbed samples without removing the casing. In this zone, <br />standard penetration tests will be systematically performed at five-foot <br />intervals and permeability tests will be performed at lO-foot intervals as <br />the hole is advanced. <br /> <br />Once sound rock is encountered, the hole shall be advanced by rotary <br />drilling equipment with NX-diameter diamond bits. A split-tube inner liner <br />shall be used in order to maximize core recovery. The cores shall be <br />labeled by site, drill hole, and depth and placed in a solid wooden box. <br />Each hole shall be logged as it is drilled and then drafted onto final log <br />sheets for inclusion in the final report. A photographic record of the <br />boxed cores shall be made and the cores shall be delivered to the State. <br />Following completion of the drilling at each hole, water pressure tests <br />shall be performed at lO-foot intervals in the rock unit with a double <br />packer. The rock foundation permeability characteristics shall be <br />determined from the test results. <br /> <br />Seismic refraction lines shall be employed at each site to provide a <br />subsurface profile between boreholes. A 12-channel seismograph is to be <br />used in conjunction with geophones to pick up the refracted shock waves <br />triggered by a small charge. <br /> <br />A-7 <br />