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A review of Application Permits on file with the Environmental Health Department reveals there has been one Application for Repairs/Additions to septic systems within the one-half mile study radius area. This can be considered a very low number of Repairs/Additions/Replacements, and can be attributed to the extremely low housing density. The subject property is in an area designated as "Hardpan"by EHD's colored map denoting the various soil types and septic system requirements throughout the County. Therefore, since the water table is deep in this area at approximately 85 feet, and the fact that the shallow soil structure at the northeast portion of the property is poor for effluent management by leachlines, seepage pits and sumps are allowed to be installed in this area. III. SOIL PROFILE AND PERCOLATION TESTING As noted on the USDA Soil Survey map,the western one-fourth of the property soils consist of El Solyo clay loam (#156), with the remaining portion of the property soils composed of Capay clay (#118). Both soil types have a high surface soil clay content percentage which is favorable for the retention of ammonium molecules emanating from septic effluent. In addition,because of this high clay content soil, a soils engineer should assess the on-site soils to provide foundation recommendations. Typically,these soil types are moderately drained with slow permeability. In this area, slow permeability occurring in the shallow soils is best counteracted by sumps or seepage pits. Table 1 below indicates the potential septic system structures to be installed based on the percolation test results. Logs of Boring using the Unified Soil Classification System (USCS) as observed from each of the shallow and deep perc test borings, are found on the respective EHD PERCOLATION TEST DATA SHEETS. Generally, the soils show variability within the deeper subsurface soils (>42 inches) with a silty, fine sand at the west end of the property, to a silty lean clay at the east side of the property. Gravel content soil was encountered in test borings on Parcels 1, 4, 6, and 7 at the depths indicated on the Perc Test Data Sheets. Percolation test depths were set at minimum depths to mitigate nitrate loading potential. Septic system sump structures have been specified for those Parcels with acceptable perc rates at typical sump depth. Since it is unknown at this time where purchasers of each Parcel will build their homes, and the fact that each Parcel is approximately 40 acres in size,percolation testing was conducted on each Parcel in logical locations, taking underground pipelines into consideration. This was done with concurrence from Mike Huggins of EHD. For example, Parcels 10, 11, 6, and 7 are adjacent to MacArthur Drive. Percolation testing was done near this Road on the premise that purchasers of these Parcels will probably build close to MacArthur Drive. The remaining, interior Parcels adjoin LLaftiture d that will connect TracyBoulevard with MacArthur Drive. Consequently,percolation ach interior Parcel was completed near this future road. These test locations maintain stance between future septic systems and domestic wells to be installed for each Parcel. Page -3- Chesney Consulting