WORK PLANS_PART 1 FILE 1 - Laserfiche WebLink

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The assembled screen and casing shall be placed in the well in such a matter as to avoid jarring impacts and to insure that the assembly is not damaged or misplaced. The casing and screen shall be suspended above the bottom of the hole at a sufficient distance to insure that neither will be supported from the bottom. Immediately after the installation of the well screen and casing, the depth of the well shall be measured by means of an approved sounding device. The Contractor shall keep and submit an accurate record of assembly including the order, number, size and length of each piece of pipe and screen installed in the well. Casing and screen sections shall be equipped with centralizer guides at 40 foot intervals. Screen fittings, bottom plates, and couplings or welding rings required to join sections of the screen shall be stainless steel as manufactured by Johnson Division, or approved equal. 2.3.7 Stilling Well A one inch diameter low carbon steel stilling well, to be used for the future purpose of water level measurements, will be installed in the well annulus prior to placement of the sand pack. The stilling well will extend 0.5 feet above ground surface. 2.3.8 Filter Pack Specifications After the casing has been installed for the full depth of the well and the screen has been placed in its proper position, an envelope of siliceous sand and/or gravel shall be placed in the annular space between the well bore and the casing screen. The filter pack material shall extend 5 feet above screen sections. Materials used for this purpose shall be cleaned, washed, and graded. The filter pack size shall be carefully selected based on the character of the water- bearing formation. Gradation analysis and selection of the filter pack grain size 11