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Q 2.1) The subject property is approximately 19 miles east of the city of Stockton. g property use consists predominately of agricultural production land, such as row crops ent crops, a winery, low density single family homes, ranchettes, and ag buildings. ing is AL-5, which will not change. Municipal sewer will never serve this area. (§ 4.2) Any of the above land use could create environmental concerns that may be discovered in the future. As evidenced by the testing of the on-site domestic well, groundwater nitrate concentrations are below the Maximum Contaminant Level (MCL) at 29 ppm. The agrichemical Dibromochloropropane (DBCP) was found to be Below Detectable Limits (BDL). Nitrate concentrations may be from agricultural fertilizer inputs and nitrogen mineralization from organic matter decomposition. The topography of the site is approximately 85 feet above MSL, and relatively level. Therefore, septic system design criteria for slopes do not have to be considered. (§ 3.1,3.2,3.3,and 3.4) The on-site septic system serving the existing residential structure has never had any problems in the past 50 years when the structure was built. A malfunctioning septic system in this locale may be attributable to installing a shallow system with an inadequate number of leachlines, and not installing seepage pits. The soils at the typical leachline depth did exhibit a surprisingly high degree of permeability for this locale as evidenced by the percolation test results obtained on both proposed Parcels. (§ 3.4) The subject property is in an area designated as "Hard pan'by EHD's map denoting the various soil types and septic system requirements throughout the County. EHD requirements in this area are for leachlines with sumps, or preferably seepage pits to be installed. (§ 5.4) Since the water table is comparatively deep in this area at approximately 105 feet MSL. Therefore, due to the clay soil types and hardpan, seepage pits are always required to be installed in this area. (§ 3.5 and 3.6) A review of Application Permits on microfiche file at EHD reveals there have been two (2) Applications or Permits for Repairs/Additions/Replacements to septic systems within a one-half mile radius on Gawne Road exclusively. (§ 5.4) This can be considered a low number of Repairs/ Additions/Replacements and appears to be mainly attributable to the very sparse development in this locale. These permits found in EHD microfiche files are located in Appendix D. (§ 5.1 and 6.0) SOIL PROFILE AND PERCOLATION TESTING (§ 5.4) The USDA Soil Map shows the on-site soil to consist of a Hollenbeck silty clay(#173). Typically, these soil types are moderately well-drained with slow permeability. However, as LLrefer,enced, below two feet, there is a fine, sandy yellowish brown silt with a fair degree of meability. Sufficient soil "fines"exist in this soil type to impede rapid percolation so treatment fluent can occur before reaching the water table, unlike what would be encountered with a y soil. Page -2- Chesney Consulting