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Well Construction <br /> Monitoring well MW-5A will be constructed using 4-inch diameter, <br />' schedule 40 PVC flush-thread casing and screen The well screen will <br />' have a nominal length of 10 feet and will have a slot size of 0 01 inch <br /> The bottom of the screen will be closed with a schedule 40 PVC flush- <br /> threaded plug The top of the well will be capped with a lockable and <br /> expandable plastic plug, and covered with a slip cap. Prior to <br /> placement, all casing materials will be cleaned and decontaminated <br /> The annular space between the borehole wall and well screen will be <br /> backfilled with clean Lone Star (or equivalent) 0/30 mesh sand The <br /> sand pack will extend from the bottom of the boring to approximately 2 <br />' feet above the top of the well screen Above the sand pack, a nominal <br /> 2-foot layer of bentonite pellets will be emplaced The remainder of the <br /> boring will be backfilled with grout The grout will consist of Type I-II <br />' cement, and will be well mixed with bentonite power and sufficient <br /> water to create a fluid. The grout will be tremied or poured into place <br /> The well will be covered with a utility box which is set flush with the <br />' ground surface The box will have a steel cover and will be set in grout <br /> to secure at in place. <br /> Well Development and Surveying <br /> P YY g <br />' MW-5A will be developed by removing a minimum of three well <br /> volumes of water Water levels will be measured before and after <br /> development The purged water will be monitored for conductivity, <br /> temperature, pH, and turbidity Purge water and rinsate will be stored <br /> in sealed 55-gallon drums pending the results of laboratory analyses <br />' The drums will be clearly labeled to indicate their contents and boring <br /> number If analytical results indicate that the water contains <br /> petroleum hydrocarbons in excess of regulatory action limits, they will <br />' be disposed of appropriately After the well is constructed and <br /> developed, it will be surveyed for elevation and located by measuring it <br /> from known landmarks. The elevation of the tops of the well casing <br />' will be the same elevation base which has been used during previous <br /> investigations at the West Weber Avenue sites <br />' Ground Wafer Level Measurements <br /> Ground water level measurements will be obtained from existing wells <br /> MW-1A through MW-4A and new well MW-5A to assess the ground <br /> 2-3 <br /> 1 <br />