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F OF WORK ng summarizes the purpose and scope of work of this investigation, and septic systemria: • Testing the physical and chemical characteristics of the soil under the future filter bed area. • Testing of the underlying groundwater and domestic water supplied by an on-site domestic well and irrigation well that now serves as a fire suppression well. • Provide septic system design criteria to: 1.) Determine the theoretical nitrate impact from the proposed wastewater septic system, 2.) Mitigate future nitrate impact emanating from the proposed disposal area, 3.)Assess mounding effects from effluent percolation onto the shallow water table, and 5.) Specify monitoring criteria. • Delineate and describe the design of the primary disposal and 100% replacement areas. II. SOIL TESTING Testing of the physical and chemical characteristics of the soil were conducted on two samples retrieved from a drilled test boring down to 12 feet. This boring is denoted on the attached Site Plan. A groundwater sample was also retrieved from this boring, which is discussed below. After retrieval of the soil and groundwater samples, two bags of bentonite pellets were poured down the boring, which created a bentonite plug from the bottom of the boring to three feet below grade. Tap water was then used to hydrate the pellets. Cuttings from the boring were then used to backfill the remaining volume. A. Soil Physical Test Results Soil physical testing consisted of percolation, infiltration, and particle size analysis of retrieved subsurface samples. Unified Soil Classifications (USCS) are found on the Percolation Test Form and Particle Size Analysis was done by A&L Laboratories of Modesto. Laboratory (USDA) classifications reveal the underlying soil to consist of a loamy sand at the 2 foot depth and a sand at the 10-foot depth. The 2-foot sample had a clay content of 10%, while the 10-foot sample had a clay content of 6%. Considering that confined animal soil containment structures must contain at least 10%clay to meet State of California Regulations, the particle size test results indicate that sufficiently, minimal clay content exists for biological activity to occur within the upper soil profile where the filter bed piping network will be placed. Biological activity is favorable for the destruction of bacteria and viruses. This upper clay content percentage will also deter saturated flow conditions that may occur in a high porosity sandy soil. The attached Water Well Drillers Report (Well Log) for the well drilled for the Cunha Draying facility in 1995 illustrates the strata underlying the property. As noted, there are significant, intermittent layers of sand and clay, which may explain the absence of nitrate in the water bearing strata from 149 feet to 161 feet. There is a considerable clay stratum above these strata from 84 feet to 149 feet, which maybe the Corcoran Clay Layer. �e'I S 7 y E 3DI dli ko4/ mj/. Page -2- Chesney Consulting