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As referenced,DWR ground water elevations indicate that ground water flow is to the southeast away from the San Joaquin River toward the historic ground water depression. The conceptual ground water model indicates that first encountered water as a shallow unconfined system that may exist in alluvium units from 30 to 40 feet bgs. This model confirms significant ground water fluctuations. Isolated perched systems may be identified. Once ground water depths are confirmed on a continuous basis across the site, the monitoring well network will be designed to reflect upgradient and downgradient sampling locations. 3. MONITORING WELL NETWORK AND RATIONALE FOR WELLS Up to four borings (MW-1 through MW-3, MW-4 optional) will be completed at the facility to accurately determine upgradient and downgradient locations and will be completed as long term monitoring wells. The first boring (MW-1) will be drilled along the north edge of the easternmost field as referenced on Figure 2. This boring is upgradient and will provide background water quality data. The second boring (MW- 2)will be drilled on the southeast corner of the easternmost field. This well will provide a monitoring location downgradient of the Site. The third boring (MW-3)will be drilled at the southeast end of the settling pond and will provide a monitoring location downgradient of the corrals. An optional fourth boring (MW-4)may be completed based on the determined ground water flow direction. Confirmed flow directions may be different from the conceptual model and initial observations. The decision to where and if this well is completed will depend on seasonal fluctuations in ground water direction over a period of at least one year. Once the three borings are completed and ground water flow direction confirmed, monitoring wells will be designed and constructed. Field adjustments to locations may occur due to access,borehole geology and observed ground water levels. Water levels within each of the borings will be allowed to stabilize within the hollow-stem auger prior to construction to achieve accurate water elevations. Figure 2 depicts the proposed locations for the monitoring wells. Additional information collected for this work plan included: DWR search of well logs, initial beneficial use information from the logs and an EDR Regulatory paper search effort. The final installation report will re-summarize these efforts detailed above. Woods Dairy March 1,2010 103-27 Monitoring Well Installation Plan 12 Revision 1