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�� KLEINFELDER File NO. 20-3653-01 July 27 , 1992 ITEM C-3 • "The depth and gradient of the water table; " During our surveys on July 16, 1992 , we were able to measure groundwater in wells located at three of the locations visited. The groundwater was measured at depths of approximately 40, 37 , and 33 feet below existing ground surface at locations 1, 2 , and 4 , respectively. The regional groundwater depth map published by the San Joaquin County Flood Control and Water Conservation District, Plate II, indicates that the depth to groundwater in this area was approximately 35 to 40 feet in fall 1991. Based on County requirements for a parcel split project such as this, we are not required to establish an on-site groundwater gradient by drilling borings. We are providing a general estimate of the groundwater gradient based on the groundwater map showing lines of equal elevation of groundwater, Plate III. On the basis of this map, we conclude that the main groundwater gradient was in roughly the north to northwest direction in fall 1991. We note that 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 one or two additional septic systems within the approximate 10-acre site. Therefore, with groundwater at approximately 35 to 40 feet deep, in our opinion the likelihood of a significant change in the nitrate level of the groundwater beneath the site, because of one or two additional systems, is very low. 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 domestic well located on site. The samples were delivered 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 received from the laboratory. This completes our scope of work at this time. Based on the above information, it is our opinion that the two proposed parcels are suitable for septic system use. The new septic systems should be located and future wells should be constructed following County requirements. Continuous monitoring of the on-site septic systems should be maintained throughout the duration of their use. Once Copyright 1992 Kleinfelder, Inc. Page 3 of 4