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October 24,2001 Job Number:LGOI-320 Page 7 Two (2)percolation tests were performed adjacent to the exploratory boring within the proposed septic leach field. The percolation test holes were set at a depth of 2.5 feet and 8.0 feet below the ground surface. The shallow test was set in a dark brown clayey sand. The deep test was set in brown fine silty sand. The percolation test casings used in both tests were a 2-inch PVC pipe with holes drilled on the bottom. Two inches of"pea gravel"were placed in the bottom of each hole, the casing was installed, and several feet of"pea gravel'was backfilled in the annular space. A preliminary percolation test was conducted on October 11, 2001 to determine if a 1 hour or 4 hour test was required. It was determined that the shallow test did not percolate and would probably not pass either a I or a 4 hour test and the deep test would require only a l hour test. Based on a preliminary test, a one(1)hour test would be acceptable for the deep. The shallow test was also tested and if it were to percolate during the test, a four hour test could be utilized. The percolation hole was pre-soaked 24-hours prior to the actual one-hour percolation test. The percolation test was conducted on October 12, 2001 in accordance with the requirements of San Joaquin County Environmental Health Division. The entire test was observed by Ted Norgard,R.E.H.S. of that office. Mr. Norgard indicated that the shallow test (2.5 ft) failed and the deep percolation test(8.0 ft)passed. The result of the percolation test ` indicates a satisfactory percolation rate of 1.7 min/in was s achieved. VII. CONCLUSIONS AND RECOMMENDATIONS In conclusion, a satisfactory percolation rate was achieved in the deep percolation test. The percolation rate was measured at 1.7 min/inch at a depth of 8 feet. The shallow percolation test at a depth of 2.5 feet failed to percolate. No ground water was encountered in any of the borings drilled on the property. The depth to ground water according to a Fall 1998 and Spring 1999 San Joaquin County Flood Control and Water Conservation District ground-water map is about 63 to80 feet below the ground surface at the site depending on the time of year. Ground water flow direction is generally to the east and southeast. Based on the results of this study,our office has found the soils to be suitable for a septic system and leach lines and seepage pits for the proposed Parcel 1. We believe that due to the proposed use and size of the parcel,the generally clayey soils,heterogeneous layering of the soils, and the depth to ground water, the use of the septic system will not negatively impact the ground water quality of the area. We recommend that the design and installation of the septic pEesoi � a.�i