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Section 2 0 Groundwater Monitoring Well Installation approximately fifteen feet below first encountered groundwater and to an estimated maximum depth of fourty five feet below ground surface. A fifteen foot well screen is proposed for these monitoring locations. Additionally,the monitoring wells will be designed and installed according to the California Well Standards, San Joaquin County Well Standards, and permit conditions of the San Joaquin County Department of Environmental Health with the following details: Borehole Diameter—Nominal 8-inch diameter. Borehole Depth—Estimated to be up to approximately 45 feet below ground surface, 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 ground surface in agricultural land or open space controlled/owned by the City of Ripon. Wells installed in public right-of-ways will however be placed just below ground surface and completed with a traffic rated Christy Box. 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 borehole. Filter Pack—The filter pack proposed is a 2/12 type (12 x 20 mesh) Monterey Silica Sand,or equivalent. The proposed monitoring well is intended for sensitive water quality determinations; therefore all filter pack material 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 interval. Slot Aperture Width —The well screen 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—Six linear feet of nominal 6-inch diameter 1/4-inch wall steel casing, or 6 x 6-inch 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 private 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, lockable pressure plug. Transition Seal—Approximately two feet of bentonite chips or pellets will be placed on top of the filter pack providing a transitional seal from the filter pack to the sanitary surface seal. April 2007 City of Ripon Wastewater Treatment Facility 2-4 Groundwater Monitoring Well Installation Workplan