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11 accordance with the Engineers'design. The drilling and reaming of the borehole will be conducted by the direct rotary drilling method to the depth and diameter specified in the Engineers design. Drilling fluid properties must conform to those specified in Section 2.1.3. B. Methods--The test hole shall be reamed to a minimum diameter and depth as specified in the Engineers design. The Contractor shall be responsible to protect the pilot hole from caving. The Contractor shall exercise caution to ensure that the hole remains straight and plumb during the reaming operations. 2.3.5 WELL CASING AND SCREEN A. Scope -- This item shall consist of furnishing and installing blank casing and well screen as specified in the Engineers'final design. B. Methods 1.A wiper trip shall be conducted to insure that the borehole is open to the total depth prior to running casing. 2. A tremie pipe of a minimum two-inch diameter shall be run into the borehole to the total depth of the casing installation. Circulation by pumping shall be established using fluid from the drilling fluid/mud tank of the same viscosity as that in the borehole. Circulation shall continue for a period of thirty minutes prior to casing installation. 3. With the tremie pipe remaining in the borehole, casing installation shall proceed in accordance with the final well design for casing installation furnished by the Engineer. 4. The casing assemblies shall be installed to the specified depth supported above the ground surface. The casing shall be capped to ensure that foreign particles are prevented from entering the casing. 5. The casing shall be suspended in tension from the surface by means of an appropriate hanger or clamp. The bottom of the casing shall be at a sufficient distance above the bottom of the reamed hole to ensure that none of the casing will be supported from the bottom of the hole. 6. Circulation through the tremie pipe shall continue during the casing installation. 7. If, for any reason, the casing cannot be landed in the correct position or at a depth acceptable to the Engineer, the Contractor shall remove the casing, recondition the borehole and reinstall the casing to the specified depth. If the casing cannot be removed from the borehole the contractor shall construct another well immediately adjacent to the original location and complete the well in accordance with these Technical Provisions at no additional cost to the Owner. The abandoned hole shall be sealed in accordance with these Technical Provisions and in accordance with any laws pertaining to proper well abandonment at no additional cost to the Engineer. 8. If any of the casing assembles collapse prior to well completion,the remaining hole shall be abandoned in accordance with these Technical Provisions at no cost to the Owner. A replacement borehole and well shall be drilled and constructed at an adjacent location as directed by the Engineer.