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A U.S. Geological Lithology Map is found in Appendix 4, which illustrates the Geology under the region of the property. As depicted in the cross-section, there is alluvium down to approximately -50 ft MSL. Below this alluvium is the Tulare Formation (QTt) consisting of unconsolidated and semiconsolidated deposits with gravel interbedded with transitional deposits and sediments. The Corcoran Clay Formation is found approximately-150 ft and-200 ft MSL. This is approximately 260 feet below ground surface. However,the Corcoran Clay has been encountered at shallower depths during the drilling of surrounding water wells. Groundwater Chemis The groan t e ne beast corner of proposed disposal area was sampled and tested un er EHD Permit SR34917 a the time of a deep boring. stainless steel bailer was lowered in rxi aug after the static wa easurement to obtain a water sample. After removal of the auger and subsequent collapse of the boring, a hydrated bentonite plug was placed on top of the collapsed mate ' , cted by EHD Sanitarian Justin Hess. As noted on the Water Analysis Report four m Appendix 9nalytes tested for include Nitrate (as NO3), Total Dissolved Solids (TDS),pH and TotTA miry. The following chart summarizes the test results: TABLE 5 UNDERLYING GROUNDWATER ANALYSIS ANALYTE LE UND MAXIMUM CONTAMINANT LEVEL (MCL) Nitrate 88 m 45 mg/L Total Dissolved Solids 744 mg/L No Standard PH 7.8 Range 6.5-8.5 Total Alkalinity 293 mg/L No Standard The nitrate concentration of the water table is almost twice the MCL Drinking Water Standard. Total Dissolved Solids is approaching saline water, which is generally accepted to be 1,000 mg/L. Total alkalinity plays a significant role in nitrate formation. A concentration of 293 mg/L can be considered medium-to-high for groundwater. It is normally the domestic water supply and the alkalinity in the wastewater effluent that determines nitrification potential. Information from nearby projects on public domestic wells drawing water from aquifers deep below the Corcoran Clay Layer(-600 feet), shows Total Alkalinity to be approximately 120 to 140 mg/L. Climatic Data: Rainfall versus Evapotranspiration It is generally regarded that when precipitation exceeds evapotranspiration(Eto), deep percolation of surface rainwater impoundment may occur. Evapotranspiration refers to water evaporation that takes place both at the soil surface and transpiration by plants, and is defined as water loss from a large field of 4-to-7 inch tall, cool-season grass that is not water stressed. A number of factors determine deep percolation and ultimately groundwater recharge,primarily domestic irrigation volumes and stormwater subsurface storage. The following chart illustrates Page-9- Chesney Consulting