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Groundwater Well Installation Standard Operating Procedure SWE-FSOP-601;Revision 1 Ahtna Southwest Environmental Operations Flush-Mount(or Subgrade) Completions Before installing any street box or vault over a well,confirm all clearances between the well cap and inside vault lid and the final height of the vault top above ground surface.Where installations are in parking lots, roads, concrete slabs, etc., consider the final height of the surrounding surface. Set and cement into position a street box or vault, usually one inch to a few inches above ground surface, depending on design requirements. Raise the top of the street box or vault slightly above grade, and the cement sloped to grade to promote surface drainage away from the well. 4.4 Temporary Monitoring Wells 4.4.1 Temporary Well Materials Materials used in installing temporary monitoring wells are the same standard materials used in the installation of permanent monitoring wells. Sand used for the filter pack (if any) should be as specified in the work plan. The well screen and casing should be stainless steel(for ruggedness and suitability for steam cleaning and solvent rinsing)or polyvinyl chloride. Appropriate Quality Assurance (QA) and Quality Control (QC) must be performed to ensure no introduction of contaminants. 4.4.2 Temporary Well Borehole Construction Ensure that borehole construction for temporary wells is of sufficient diameter to accommodate the well casing and associated well construction materials. For well installation in an open borehole using a drill rig, ensure the annular space is approximately 2 inches to allow the uniform deposition of well materials around the screen and riser and allow the passage of tremie pipes and well materials without unduly disturbing the borehole wall. Alternatively, boreholes may be constructed using hand augers or portable powered augers (generally limited to depths of ten feet or less). If a drill rig is used to advance the borehole,the augers must be pulled back the length of the well screen or entirely removed before sampling. When hand augers are used, the borehole is advanced to the desired depth (or to the point where borehole collapse occurs).When borehole collapse occurs, the auger bucket is typically left in the hole at the point of collapse while the temporary well is assembled above ground. When the well is completely assembled, a final auger bucket of material is quickly removed, and the well is immediately inserted into the borehole, pushing, as needed,to achieve maximum penetration into the saturated materials. 4.4.3 Temporary Monitoring Well Types Temporary monitoring wells are constructed in various ways depending on project requirements and site conditions. A few acceptable examples are described below. Because temporary well purposes and construction are project-specific, detailed procedures for construction should be included in project work plans. 1. No Filter Pack.After the borehole is completed,the casing and screen are simply inserted.This is the least expensive and fastest well to install. Note: This type of well is extremely sensitive to Page 14 of 16