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File No. 20-3652-01 kn KLEINFELDER July 30, 1992 ITEM C-3: "The depth and gradient of the water table;" During our residence surveys on July 15, 1992, we were able to measure groundwater in two wells. Groundwater was measured at depths of approximately 93 and 98 feet below existing ground surface at locations 1 and 5, respectively. The regional groundwater depth map published by the San Joaquin County Flood Control and Water Conservation District, Plate II, indicates the depth to groundwater in the site area was approximately 100 feet in fall 1991. On the basis of the groundwater map showing lines of equal elevation of groundwater, Plate II1, we conclude that the main groundwater gradient is in roughly the northwest direction. ITEM C-5: "Other information as required by the San Joaquin Local Health District to determine the cumulative effect of the existing and the proposed development on ground water contamination." Our scope of services did not include a detailed evaluation of the potential for the septic systems to affect the quality of groundwater. However, the project involves only three additional septic systems over an approximate 40-acre site. Therefore, with groundwater at a depth of approximately 93 to 98 feet, in our opinion the likelihood of a significant change in the nitrate level of the groundwater beneath the site, due to three additional systems, is remote. If additional more-concentrated development is planned in the area, we suggest that consideration be given to completing a nitrate loading study. As requested by San Joaquin County Environmental Health in their "Conditions of Approval," we collected water samples from the well located on site and delivered the samples to FGL Environmental laboratory in Stockton for nitrate content and DBCP testing. The test results will be submitted under separate cover as soon as the results are available. This completes our scope of work at this time. Based on the above information, it is our opinion that the four proposed parcels are suitable for septic system use. The septic systems should be located and future wells should be constructed following County requirements. Continuous monitoring of the septic systems should be maintained throughout the duration of their use. Once this report is reviewed by Environmental Health Services, we would be pleased to furnish a proposal for providing whatever additional information they may require for their evaluation. Copyright 1992 Kleinfelder, Inc. Page 4 of 4