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� J (§ 4.2) Any of the above land use could createp3mental concerns,that may be discovered in the future. As evidenced by the testin of on domestic w is (old and new wells), roundwater:•n.it-rate• - neent ns a ov "�""� .. g the aximum contaminant Level (MCL), as is Dibromochloropropane (DBCP))CoftentTratiofis of these two constituents are from agricultural iii"puts"and-nitrogen••mineraliz`alibn. This will also be discussed in gJ*Qn..4•,�f„1�sxepo t As depicted on the Tentative Parcel Map, the topography of the site is approximately 65 feet above MSL, and relatively level. Therefore, septic system design criteria for slopes do not have to be considered. (§ 3.1,3.1,3.1,and 3.4) The septic system tha .serves the existing Boersma residential structure has been functioning properly for approximate 15 ye withoutn�rom bles. This maybe attributable to the indigenous sandy/silty soils as evidenced by the percolation test results obtained for both proposed Parcels. (§ 3.4) The subject property is in an area designated as and/Sandy Areas” by`EHD's map " denoting the various soil types and septic system requiremen�throughout the County. EHD requirements in this area are leachlines and possible sumps, with 80 feet of leachline per bedroom. (§ 5.4) Since the water table is comparatively shallgw ih this area at approximately 25 feet / (discussed in the`foilowing-Sect-ion);•and the fAd that the shallow soil structure is adequate for proper effluent management, seepage pits are not allowed 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 five (5) Applications or Pe qr Repairs/Additions/Replacements to septic systems on North Ripon Road exclusive) (§ 5-.-4))^�his can be considered a medium number of Repairs/ Additions/Replacements and appears to be mainly attributable to the installation of additional leach pipe. All permits found in EHD files pertaining to septic systems on North Ripon Road can be found 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 Delhi Loamy sand (#142). , Typically, these soil types are excessively drained with rapid permeability according to the N.R.C.S. This permeability was confirmed by the perc test results. Sufficient soil "fines"exist to impede rapid percolation that would occur with an extremely sandy soil. Therefore, treatment of septic effluent can take place before reaching the water table at approximately 25 feet below grade. (§ 5.2,-5.3,and,,5:4)_A Log of Boring using the Unified Soil Classification System (U.S.C.S.), as observed in thek42 inch shallow perc test borings, is found on the EHD PERCOLATION TEST M DATA SHEET. Qeveraily, the underlying soils show a consistent very fine sandy silt/silty fine sand with very little `clay. o cemented silts hardpan soil stratum was discernible at depifisoff`wnto he maximum ',,_leaehline trench depth of 42 inc Page -2- Chesney Consulting