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i . The subject property is in an area designated ' p p y grated as Hardpan by EHD's colored map denoting the various soil types and septic system requirements throughout the County. Therefore, since the water table is deep in this area at approximately 122 feet, and the fact that the shallow soil structure is typically poor for effluent management by leachlines, seepage pits and sumps are allowed to be installed and always are in this 'area. ii SOIL PROFILE AND PERCOLATION TESTING As noted on the USDA Soil Surv�e ma the on-site soils on the east side of the entire property Y p� p p Y consist of San Joaquin sandy to yaum (#236). On the west side of the property, the soils are a Madera sandy loam (#193). Typically, both these soil types are moderately drained with very slow permeability. In this area, slow'permeability occurring in the shallow soils is best counteracted by sumps, or seepage pits. As discussed below, none of the four shallow perc test borings (42 inches in depth) had acceptable percolation, and in fact, had zero percolation at the end of four hours. The maximum acceptable perc rate is 60 min/in for shallow perc tests. Logs of Boring designated by tJ Unified Soil Classification USCS System soil classifications Y ( ) as observed from each of the per test borings are found on each of the respective EHD PERCOLATION TEST DATA SHEETS. Generally, the soils show variability within the subsurface soils (>60 inches) with a silty clay at the south end of the property, to a fine sandy silt in the north end of the property., Below five feet, the soils are generally a clayey/silty gravel and a lean clay. For Parcels 1 and 2, a fine sandy silt/silty sand was encountered at the percolation test til. depths represented on the Pere Test Data Sheet(8 ft and 12.5 ft, respectively). Consequently, the percolation tests were set withiA this stratum where permeability was favorable. Percolation testing was conduct)Id on proposed Parcel 1, 2 and 4 near the middle of each property. This location maintains sufficient distance between future septic systems that may be installed in these locations and surrounding�iiwells. Perc test locations for Parcels 3 were contingent upon the existing well location, as denotl on the Tentative Map. The locations of the percolation tests are measured as illustrated on the Tentative Map. The following information describes the preparation of the percolation test borings and the actual perc testing: On May 10, 2005, one shallow fere test boring of 42 inches in depth and one deeper test boring p p g varying from 8 to 14.8 feet were',i[drilled on proposed Parcels 1, 2, 3 and 4 in the areas referenced on the Tentative Map. The sidewalls of the shallow borings were scored with a pry-bar and the loose material removed. Two inches of fine gravel was placed at the bottom and three-inch erforatc PVC vipe was inserted. All theF�test borings were pre-saturated on May 12, 2005 at 0930 hrs with 12 inches oTwat-er 1 II On May 13, 2005, 0900 hrs, percolation testing commenced for all eight borings. There was standing water after the 24-hour soak period in all four of the shallow perc tests borings, as illustrated in the Table below. Consequently, EHD Perc Test Procedure#1 was conducted for these borings for four hours to document their perc rate failure over the four-hour test period. i P -2- Chesney Consulting