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2012 Monitoring Well Installation Work Plan November 8, 2012 Former NestO USA, Inc. Facility 3.2 WELL CONSTRUCTION The proposed monitoring wells will be constructed of two inch diameter Schedule 40 PVC casing with up to 10 feet of 0.020-slot screen. As indicated in Section 2.2, the well screen interval will be field determined based on lithology and the target aquifer zone (Upper A or Lower A zone). A#3 RMC Lonestar or equivalent sand filter-pack will fill the bottom of the borehole to one foot above the top of the screened interval. At least two feet of bentonite chips will be placed above the sand filter. Bentonite-cement grout will fill the borehole from the top of the bentonite chips to two feet below ground surface, and the surface seal will be completed with neat cement. A road-grade steel box for flush-mounted well completion will be installed to protect the wells. 3.3 WELL DEVELOPMENT The newly constructed wells will be developed to remove fine particles from the well casing, screen, and filter pack. The wells will be developed by surging the water inside the well screen with a surge block to pull fine material out of the filter pack and screen. Water and sediment will then be pumped and/or bailed from each well. The well development will continue until the turbidity of the purge water is: Less than 50 nephelometric turbidity units, pH has changed less than 0.1 pH units, • Temperature has changed 1 degree F or less, and Conductivity has changed by less than 10%. 3.4 WELL LOCATION SURVEY After well installation, the well locations will be surveyed by a California licensed surveyor with respect to the State Plane Coordinate system. Elevations will be determined to within +/-0.1 foot using the North American Vertical Datum of 1988. Both the top of the well casing (the measuring point for depth-to-water measurements) and the ground surface adjacent to each well will be surveyed for elevation. 4 WELL MONITORING AND SAMPLING Upon completion of well development activities, passive diffusion bag (PDB) samplers will be installed in the wells at two depths within each screened interval. The PDB samplers will remain in place for no less than two weeks, and will be recovered for sampling of the CDCs prescribed in the Nestl6 Ripon Monitoring and Reporting Program (MRP). A California-certified environmental laboratory will analyze the groundwater samples in accordance with EPA Method 8260B. The results of the vertical profiling will be evaluated to determine the interval with the highest COC concentration. Based on the results, a PDB sampler will be launched in each well at the selected depth to be recovered during the subsequent quarterly MRP sampling event. Quality control (QC) samples for this project include field duplicates and trip blanks. Field duplicates are collected during the quarterly sampling events at a ratio of one duplicate per Page 3 of 4