Laserfiche WebLink
Mr. Robert McClellon <br />May 28, 2009 <br />Page 4 <br />40 determined in the field depending on encountered subsurface geology. Drill cuttings will be <br />used as backfill material or spread on the ground around the immediate location. <br />Construction Details <br />Proposed construction details are shown in Figures 4a and 4b. The probe casing will consist of <br />'/2 -inch diameter or greater flush -thread schedule 80 PVC. The probe screen will consist of '/2 - <br />inch diameter or greater flush -thread schedule 80 PVC 0.010 -inch well screen. The bottom of <br />the screen will be capped with a secured end cap. No glue will be used during any part the <br />construction of the probe. After the probe is in place the borehole will be backfilled with a filter <br />pack consisting of pea gravel to approximately 6 inches to 1 foot above the screen. A five-foot <br />thick (minimum) layer of hydrated bentonite will be installed on top of the pea gravel to isolate <br />the screened interval from any surface intrusion. The remainder of the borehole will be <br />backfilled with native soil cuttings, and five-foot hydrated bentonite seal at the surface. <br />The surface of each probe will be protected by installing a locking metal monument box encased <br />in an approximately 2 -ft x 2 -ft concrete apron. The surface completion will include a '/-inch <br />brass labcock valve for sampling. Forward will provide a lock, keyed the same as the locks <br />securing existing monument boxes. <br />Subsurface geologic conditions encountered in the field and all probe construction details will be <br />summarized in boring logs and included as part of the installation report. <br />Health and Safety Considerations <br />Work on or near landfill sites warrants special precautions to mitigate potential combustible gas <br />hazards, worker exposure to the trace constituents of LFG, or exposure to physical hazards that <br />may be encountered. <br />A health and safety (H&S) plan for the well installation activities will be prepared prior to <br />beginning the work. The H&S plan will describe potential hazards and will outline site-specific <br />protection, monitoring and record keeping provisions. <br />REPORTING <br />An installation report will be prepared for submittal to AWI following completion of the probe <br />installations. The report will include a summary of all drilling and installation details, and will <br />include boring logs documenting encountered geologic conditions and all probe construction <br />details. <br />0 <br />