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Section 2 Groundwater Monitoring Well Installation designed and installed according to the California Well Standards, San Joaquin County Well Standards, and permit conditions of the San Joaquin County Environmental Health Department with the following details: Borehole Diameter—Nominal 8-inch diameter. Borehole Depth—Estimated to range from 115 to 145 feet,depending on first occurrence of groundwater. Well depth will allow for normal fluctuations of the shallow groundwater table. Casing Diameter—Nominal 2-inches. Casing Materials—ASTM F480 Schedule 40 flush threaded PVC blank casing. Top of casing shall be approximately two feet above the ground surface in all areas where traffic is not of concern. For wells constructed on or near public or private roads,the well casing will be completed several inches below grade. Well Screen—Factory slotted ASTM F480 Schedule 40 PVC well screens. Approximately 15 linear feet of flush threaded well screen will be placed in the bottom of each borehole. The timing of the well installation will however affect the manner in which the well screens are installed, due primarily to the seasonality of groundwater elevations observed in existing WWTF wells. For instance, if the wells are drilled during the early winter/spring/early summer months, the entire 15 feet of well screen will be submerged, below the unit representing first encountered groundwater. Should the wells be installed in the late summer/fall/early winter months, approximately three to five feet of well screen will be placed above first encountered water. All reasonable attempts shall be made to assure that the well screen is a minimum of 24 feet below ground surface, assuring an annular seal of no less than 20 feet in length. Filter Pack—The filter pack proposed is a#2)12 type (12 x 20 mesh)Monterey Silica Sand, or equivalent. The proposed monitoring wells am intended for sensitive water quality determinations; therefore all filter pack materi il shall be handled to avoid contact with contaminants as discussed in Section 11 of the California Well Standards. The filter pack will extend two feet above the top of the screened i nterval. Slot Aperture Width—Well screens will be installed with a 0.020-inch aperture width. The gradation is based on the initial selection of the filter pack and is sized to retain, at a minimum, the D90 of the filter pack. Protective Surface Casing—For above grouncompletions, six linear feet of nominal 6-inch diameter '/4-inch wall steel casing, or 6 x 6-in square tubing, equipped with a lockable, removable cap will provide the protective surface casing. This casing will be cemented in place from approximately two feet above ground surface to a depth of four feet. A 3.5 x 3.5-foot square or 3.5-foot diameter circular,4-inch thick concrete pad will be poured surrounding each well. For completions in or near public or pri ate roads,the wells will be completed with a traffic rated Christy box, cemented in place and slightly above grade. Cement will be pored around the Christy box and finished such to promote the shedding of surface water away from the well. Well Cap—2-inch diameter expandable, lock ble pressure plug. March 2006 Lockeford CSD 2-3 Groundwater Monitoring Well Installation Workplan