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L . LPercolation Testing LThe second procedure for the analysis of the subsurface soils consisted of percolation testing. The exact location for each of the four proposed leachf eld areas was determined by the Lengineering firm of Dillon & Murphy. Shallow and deep soil horizons were "perc" tested in each of these four leachfield areas. The shallow perc tests were performed at depths of approximately 42 inches. The deep horizon tested was the seven to nine ft depth. This deep perc test illustrates percolation rates that will occur at depths below the leachline trench, in definite native material. The third perc testing program dealt with the percolation rates for seepage pits. These seepage pit perc tests were conducted at two locations as can be noted on the attached plot map: between leachfields 1 and 2 and between leachfields 3 and 4. The percolation testing was performed in accordance with County of San Joaquin and U.S.E.P.A. procedures and referenced at the end of this report for brevity. The perc test results found in the Appendix indicate very slow, and one non-existent percolation rates for each of the four shallow leach field areas. This was to be expected considering the high clay content of the soils at this depth. A note of importance was our procedure of deeply scoring the sides of the borings to open smeared soil surfaces from the drilling process. This scoring procedure was performed on all of the borings prior to 24 hr saturation. Perc test results for the seven to nine ft depths indicate favorable perc rates in comparison to the shallow perc rates. Again, we do see a somewhat relative correlation between soil structure and percolation rates. The soil structure at these depths, which is native material, possesses a higher sand content than the shallower depths, thus a faster perc rate. This data is important in illustrating the variability of the soil for effluent acceptance rates which will undoubtedly exist in the soil horizons for each of the four leachfields. Due to wastewater loading rates, seepage pits will have to be designed into the septic systems. Therefore, two 25 ft deep perc test were performed. These perc test borings simulate seepage pit test data. The perc test procedure for these two borings deviated from the above-referenced San Joaquin County percolation test procedures in the following respect: The falling head test was performed for each test hole. The sides were scored, and the boring filled with water to � 3 yaCleyy Pgsearch