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n n (§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, and the ag irrigation well, groundwater nitrate concentrations are high, presumably from agricultural inputs. This will be discussed in Section 4 of this report. As depicted on the attached USGS Map, the topography of the site is 15 feet above MSL,with a very slight land declination toward the west. Therefore, septic system design criteria for slopes do not have to be considered. (§ 3.1, 3.2, 3.3, and 3.4) The septic system that serves Consuelo Noceti's residence has been functioning properly without any problems since the house was built in 1971. This maybe attributable to the indigenous sandy soils. A permit for the original system was found in EHD files (Permit No. 71-076). (§ 3.4) The subject property is in an area designated as "Sand/Sandy Soils"by EHD's map denoting the various soil types and septic system requirements throughout the County. (§ 5.4) Therefore, since the water table is shallow in this area at approximately 12-13 feet, and the fact that the shallow soil structure is adequate for proper effluent management, seepage pits are not allowed to be installed in this area. k (§ 3.5 and 3.6) A review of Application Permits on microfiche file at EHD reveals there have been three Applications for Repairs/Additions/Replacements to septic systems on Bowman Road exclusively. (§.5.4) This can be considered a low number of Repairs/Additions/Replacements, and can be attributed to the indigenous sandy soil type that is found predominately in the shallow soils. i i ` (§ 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 Veritas fine sandy loam (#266) and a small portion of the eastern edge of the property is Honcut sandy loam (#175). Typically, these soil types are well drained with moderately rapid permeability. Sufficient soil "fines"exist to impede very rapid percolation, unlike what would occur with a very sandy soil. Therefore, treatment of septic effluent can take place before reaching the water table. As discussed below, the shallow perc tests for both Parcels had excellent percolation, which is indicative of these soil types. (§ 5.2, 5.3, and 5.4) A Log of Boring using the Unified Soil Classification System (USCS), as I observed in a 9.5 foot deep backhoe test pit completed on Parcel I near the proposed leachfield { area, is found on the EHD PERCOLATION TEST DATA SHEET. Generally, the underlying soils show a thin cemented silts hardpan soil at approximately six feet and eight feet below the ground surface. The remaining soils are a silty fine sand/sandy silt. (§ 6.1) Percolation testing was conducted in the locations as illustrated on the Tentative Map found in Appendix C. As referenced, the perc test location for Parcel 1 is south of where the anticipated s house will be built. i Page-2- Chesney Consulting