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The soils testing and investigation has found the indigenous soils under the proposed wastewater effluent disposal area to contain a predominately sandy silt(loam) material with rapid infiltration and percolation capabilities. II. SOIL SUITABILITY STUDY FINDINGS A. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION SSS§ I.I. As noted on the Google aerial map, surrounding land use to the north, west and southeast is farmland with sparse residential structures. To the east and southeast is the City of Ripon. The surrounding agricultural land has been in production for many decades. The subject property is zoned AU-20. SSS§ 3.1,3.2,3.3,3.4,3.5,3.6. Application files at EHD for repairs/replacements/additions are not available at this time for review of existing systems within a one-half mile radius study area. It is known that the Ripon area consists of a sandy soil structure, as was encountered. Consequently, septic system failure occurrence is minimal. A lifespan for the future disposal area is indeterminable due to several known and unknown factors,but can be considered longer than a system installed in a heavier clay soil. The project site has relatively level terrain. There will be no need to incorporate design considerations for slopes. B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS The United States Department of Agriculture - Soil Conservation Service (USDA-SCS) indicates the majority of the property is veritas fine sandy loam(#266). However, the filter bed will be installed in Honker-Vallecitos-Gonzaga complex (#176), which is also a sandy loam. SSS§ 5.2. The subsurface soil investigation and testing began with hand drilling one 36-inch deep boring in the proposed effluent disposal location. This depth represents approximate effluent acceptance at the proposed depth of the soil-effluent interface. Soil cuttings from the bottom of this boring were retrieved for chemical analysis. l NLS§1.1, 1.2. As the noted on the A&L Laboratory Soil Analysis Reports, chemical analyses of the soil sample quantify the constituents that influence nitrate loading potential from this project. The important parameters for nitrate loading assessment are the organic matter, pH, cation exchange capacity(CEC), clay content percentage, along with nitrate-nitrogen content of the soil. As noted,the organic matter in the surface soils is low, which was to be expected. This concentration suggests a low potential for future nitrate-nitrogen loading from indigenous nitrogen soil content. The Estimated Nitrogen Release (ENR) was measured at 48 lbs.N/Acre which is very low. Organic matter (carbon source) is required for denitrification so there is also a lower denitrification potential within the soil. The nitrate-nitrogen concentration is very low at 1 ppm; again a low potential of nitrate contribution from the indigenous soil concentration. 2