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I avoid soil cross-contamination. Well casings will be inspected to ensure they are clean when installed. 2. Well Installation Activities A registered geologist will log the well boring. Sieve analyses will be conducted on selected formation samples, as determined by the geologist. The well log will include the general character, type, and depths of materials penetrated, and any pertinent observations on the depths of water-bearing horizons, or other data that may assist in the interpretation of the subsurface geology. As part of the log, the geologist will accurately determine the depth from which cuttings and fluid samples are taken for analysis. A well installation report will be included with j the log and will show, by depth, the bottom of the boring, screen location, granular backfill, seals, grout, cave-in, and height of protective casing above ground surface. The actual composition of the granular backfill, seals, and grout will be recorded on the well detail. The well log sketch will include the protective casing detail, details on the size and type of screen used, and centralizer design (if used). Any variations in the proposed well design will be noted,with the depths at which such changes are required. C. MONITORING WELL DESIGN Proposed monitoring well construction materials (e.g., well casing,.screen, filter pack, seal, grout, and well protection) are described in this section. 1. Well Casing and Screen Well casing and screen sections will be 10 or 20 feet in length and will be flush couple threaded polyvinyl chloride (PVC) (ASTM F480), Schedule 40,four-inch nominal inside diameter. No PVC solvent will be used. It is anticipated that the well screen will have a 0.020-inch slot size; however, the screen slot size will be confirmed after analysis of drilling soil samples. The well bottom will be closed, and the bottom cap will either be threaded or attached with stainless steel screws. The well screen and casing will be kept clean and free of foreign matter, and washed with approved water prior to use. Well centralizers, if deemed necessary to maintain the appropriate plumb, will be PVC or stainless steel, and will be attached to the casing using stainless steel. The top of the well casing will have a removable Schedule 40 oversized cap to prevent well contamination. The contractor will install the screen and casing using the materials described previously. The contractor will record the well construction details on "as-built" plans, a copy of which will be given to CFL. A well installation record will be included with the well log as indicated above. Care will be taken to install the protective casing and well casing plumb. Centralizers, if used, will be utilized as per the installation workplan to center the casing in the bore. Centralizers will be located to minimize interference with placing the sealing material as Project Workplan 3 SA1433 July 30,2004 nAsa01433\gwmwiwp\workplan.doc