WORK PLANS - Laserfiche WebLink

Home Browse Search

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. 3.0 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. As referenced, the borehole geology will be used to refine the placement of well screens and gravel pack envelopes. 3.1 Well Casing and Screen Well casing and screen sections will be 10 feet in length and will be flush couple threaded polyvinyl chloride (PVC) (ASTM F480), Schedule 40, two-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 French Camp. 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 installed to center the casing in the bore. Centralizers would be located to minimize interference with placing the sealing material as specified. Centralizers would not be attached to the well screen or that part of the well casing exposed to the gravel pack. All joints will be constructed to provide a straight,non-constricting, and watertight fit. Any casing or screen deformation or bending will be minimal to the point of allowing the insertion and retrieval of the pump and/or bailer optimally designed for that size casing. The contractor will provide means of protecting the well bore and casing assemblies, when installed, from the entrance of foreign objects. The entry of nuisance water, such as rainfall runoff or construction water from other construction activities, into the borehole will be prevented. The contractor will protect the work from damage and take all measures necessary to prevent delays. 3.2 Filter Pack, Bentonite Seal, and Grout Well backfill materials (e.g., filter pack, bentonite, and grout) will form a continuous annular filling around the well casing. The filter pack will be sand composed of sound durable particles French Camp-Monitoring Well Installation Workplan 3 SAB027100 September 2006 CADocuments and Settings\mlagorio\Local Settingffempomry Internet Files\OLK9F\Work Plan