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Now *Ago,, Sievers Soil Suitability Study Page 4 i Due to the cemented nature of the soils encountered in the test pits, it did not appear that a suitable shallow percolating stratum existed in the general area. Consequently, a boring was made for a deep pit percolation test. This test hole was also logged by a civil engineer. A description of each soil encountered is contained in the Appendix as Log of Deep Pit Percolation Test Hole. Cemented soils were also encountered in this test hole until a depth of 21.5 feet. At this point a well graded medium sand was encountered until the maximum depth of 25 feet. Two percolation tests were performed, consisting of a shallow (36 inches) and deep (25 feet) test. For approximate location of percolation test holes(PT) see Tentative Parcel Map in the Appendix. Both percolation tests were performed in 8 inch diameter test holes that had a 4 inch perforated pipe backfilled with gravel. Both holes were filled with water 24 hours prior to running the tests. The last half hour of the tests readings were witnessed by a county health official and the test data obtained is enclosed in the appendix. A summary of the test results is presented next: Diameter of Depth of Test No. Hole Hole (,in.L Percolation Rate (min/in) PT-1s 8 36 No Percolation PT-1d 8 300 0.56 As anticipated and due to the cemented soils, the shallow percolation test showed no water drop over a 30 minute period after water remained in the test hole over night. VII CONCLUSION Based on the results of the shallow and deep percolation tests, the soil profile, and the performance of the septic systems in the surrounding area, it is our opinion that the new homesite resulting from the proposed parcel split should be suitable for the use of a septic tank, leach line, and dry well (25 feet deep) sewage disposal system. The proposed system however, should be properly designed and installed according to current San Joaquin County criteria. In addition, it should be noted that the proposed homesite is located in a low area compared to the surrounding grade. The cemented soils encountered at a depth of 2.0 to 5.0 feet act as an effective barrier to percolating rain water and provide for considerable seasonal perched water as indicated by —r trickling into test pit #2 and also the saturated surface silts in test pit #1. It is recommended that the location of any proposed septic system be kept on a uphill gradient and at least 6 feet above the lowest grade on the subject property. Based on the depth to ground water in the area, and the size of the proposed parcel, it is our opinion that the installation of the proposed septic systems, if properly installed, should not adversely affect the quality of the ground water in the area. VIII LIMITATIONS The conclusions of this report are based on the information provided regarding the existing and proposed development, the use of the subject property, and the site conditions as they existed at the time we P pERS0 D � Z w O � 4Ssor\ V