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_ J To investigate subsurface soil conditions and characteristics, five backhoe test pits were excavated in the referenced wastewater disposal area under ASTM Standard Practice for Subsurface Site Characterization of Test Pits for On-Site Septic Systems. Test Pit locations are denoted on the Site Plans. The Photographic Plates clearly illustrates the surface and subsurface soil characteristics primarily consisting of fine sands and silt, with three soil horizons, A, B and C. Horizon C is approximately three feet below the plow layer, consisting of the yellowish brown, silty sand material. Excavated soil shows compact soils with some cemented hardpan characteristics, down to 15 feet. 2.2 Soil Physical Test Results NLS§ 1.2 The National Resources Conservation Service (MRCS) - Soil Conservation Service indicates the soil type of the proposed disposal area, as well as the entire subject property is Veritas fine sand loam (#266). The Veritas soil has been denoted as moderately well drained and deep to a hardpan. Permeability is moderately rapid. -Available water holding capacity, on average, is 0.12 to 0.15 inch/inch for the top five feet of soil, for a total of 7.2 to 9.0 inches of water. Field capacity on average is 0.24 to 0.31 inch/inch for the top five ft of soil, for a total of 14.4 to 18.6 inches of water. Field capacity is described as water held in the spaces between soil particles in which water under the influence of gravity drains from the larger pore spaces but remains in the smaller spaces being held against gravity. Over the proposed primary disposal area of approximately 3 acres (130,700 ft),the top five feet of soil can theoretically hold: 3.0 acres x 27,154 gals/ac-in x -16.5 inches = 1,344,123 gallons of water_ 325, 851 gals/ac-ft= 4.1 acre feet of water. I SSS§ 5.2 A deep boring was conducted with a Mobile B-24 Drill Rig to further delineate the deeper subsurface soil characteristics, down to 15 ft below grade. The decision was made to terminate the deep boring at 15 feet since the on-site domestic well was sounded, with standing water level measured at approximately 22 feet below ground surface. This depth most likely corresponds with the water table depth. Capillary fringe water was not encountered in the 15 ft deep backhoe test pits. The Logs of Boring for each 15 ft drilled perc test boring is found on the Field Percolation Rate Forms. SSS§ 5.3 The Soil Analysis Reports from A &L Laboratories of Modesto, summarized in Table 5, illustrate Particle Size Analysis for each sampled depth of 2 ft, 5 ft, 10 ft and 15 ft below the ground surface. Silt and sandy loam, loam and clay were the soil types encountered with the clay soil found at the 10 and 15 ft depths under the proposed disposal area. As will be discussed in the Conclusions Section of this report, the depth of this clay stratum may be beneficial for the mitigation of nitrate impact. 2.3 Percolation and Infiltration Test Results Eight percolation tests at four prescribed depths were conducted within the proposed disposal area 11 designated as "Phase 2" on the Site Plan. One set of four perc tests were done near the Northeast Corner(NEC) of this disposal area and the second set of four perc tests were done near the Southwest Corner(SWC) of the disposal area. This disposal area is a total 3.89 acres in area, and is located in the northwest corner the subject property. Page -6- Chesney Consulting 1