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k`■ KLEINFELDER File No. 20-3474-13■ ND July 30, 1991 ITEM C-3 • "The depth and gradient of the water table; " During our surveys on June 26, 1991, we were able to measure groundwater in five wells, two within the Ace Tomato facility and one at each residence. The groundwater was measured at depths of approximately 32 to 41 feet below existing ground surface. 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 this area was approximately 40 feet in Fall 1990 . 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 test borings. We are providing a general estimate of the groundwater gradient based on the published map. Based on the groundwater map showing lines of equal elevation of groundwater, Plate III , we conclude that the main groundwater gradient is in roughly the north direction. This completes our scope of work at this time. Based on the above information, it is our opinion that the proposed parcels are suitable for septic system use. However, our evaluation assumes that the existing structures and septic system on Lot 6 will remain, and that any construction on the remaining parcel would be limited to a light industrial facility with a single septic system for domestic use only. If the existing or future systems will service more than approximately 30 employees each, or if the proposed facility will contain a kitchen or produce industrial waste water, additional evaluation will likely be required. 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 additional septic system within an approximate 46. 5-acre site. Therefore, with groundwater at approximately 32 to 41 feet deep, the likelihood of a significant change in the nitrate level of the groundwater beneath the site, due to one additional system, is remote. If additional more concentrated development is planned in the area, we suggest that consideration be given to completing a nitrate loading study. The new septic system should be located and future wells should be constructed following County requirements. Continuous monitoring Copyright 1991 Kleinfelder, Inc. Page 3 of 4