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Kennedy/Jenks Consuhants Plan it is assumed that the historical gradient and direction is still representative of current conditions for the following reasons: • The screened interval for Well MW-12 did not penetrate the entire aquifer. Analysis of the boring log shows that the deepest soil core sample (100 feet bgs)was logged as "wet". • The screened interval for Well MW-18 did not penetrate the entire aquifer. Analysis of the boring log shows that the deepest soil core sample (100 to 101.5 feet bgs)was logged as "wet'. • Wells MW-10R and MW-22 are installed in the same zone (intermediate) as Wells MW-12 and MW-18. Because Wells MW-10R and MW-22 are still active monitoring wells and Wells MW-12 and MW-18 did not penetrate the entire aquifer, it is reasonable to conclude that the water bearing zone(s)for Wells MW-12 and MW-18 may still be present, but the current water level is deeper than the bottom of the screen. Groundwater contours for other portions of the Site are generally consistent with historical gradients and directions, so without additional information, it is also reasonable to conclude that current flow direction and gradient beneath the Title 27 ponds is consistent with historical direction and gradient. Based on contouring groundwater elevation data collected in January 2008 from Wells MW-10R, MW-12, MW-18, and MW-22, groundwater flow in the immediate vicinity of the Title 27 ponds has a bearing of 48 degrees and a gradient of approximately 0.006 feet per foot (ft/ft). Historical contouring of the shallow zone was not done because based on the current understanding of the Site hydrogeology, it is believed that the shallow zone is no longer existent, that it represented small pockets of perched groundwater that are no longer present, and that first encountered groundwater is the intermediate zone. These assumptions will be evaluated as a part of this Work Plan as outlined in Section 5. 3.4 Assignment of Wells and Evaluation Based on the groundwater elevation contour map presented on Figure 8, a groundwater flow bearing of 48 degrees, and a gradient of 0.006 ft/ft,the existing monitoring wells in the vicinity of the Title 27 ponds have been designated as shown in Table 2. 3.4.1 Evaluation of the Shallow Zone At this time, there are no active monitoring wells in the shallow zone in the vicinity of the Title 27 ponds; the existing shallow zone wells are dry. If groundwater were present in the shallow zone, and available for sample collection, these monitoring wells would satisfy the intent of Title 27. An evaluation of the presence/absence of shallow groundwater is needed to determine if additional groundwater monitoring wells are needed in this zone. Page 8 Work Plan for Improved Detection Monitoring Program Musco Family Olive Company, Tracy, California evs-e�.ppv'dmmyonnznsoioa oo m�p.pia.wo,.wdpvd�.z�dmpbdi d. .miVeport text-09-26.doc