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II. SOIL SUITABILITY STUDY FINDINGS A. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION SSS§ 1.1. As referenced, surrounding land use consists of agricultural operations and rural residential. These properties all have on-site domestic well water and septic systems. SSS§3.1,3.2,3.3,3.4,3.5,3.6,3.7,6.8. EHD Permit Application files for septic system repairs/ replacements/additions reveal three Permits for additional drainage on 10/64, 6/74, and 11/78. This illustrates the inadequacy of the shallow soils to manage effluent flows. Therefore, deeper disposal structures, specifically three sumps, is incorporated in the system operation parameters for this project, are referenced in Section IV of this report. B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS The United States Department of Agriculture - Soil Conservation Service (USDA-SCS) indicates the property soil consists of Madera sandy loam(#193). The shallow effluent disposal system will be installed in this soil type. The well log for the onsite domestic well is found in Appendix D, and reveals intervening stratums of sand, clay and rocks. SSS§5.2. The surface and subsurface soil investigation began on April 1,2021 with the drilling of a 23 ft exploratory boring,and 13 ft and a 40 inch deep boring. Subsequent 10.5 ft and 36 inch perc test borings were drilled based on the encountered soils during drilling. The test borings were drilled using a truck-mounted B-24 drill rig,adjacent to the south of the proposed location of the disposal area so that no disturbance of the effluent accepting soil profile would occur. NLS§ 1.1, 1.2. Composite soil samples from the test boring were retrieved for chemical and particle size analysis from the three depths. The 13 ft and 23 ft soil samples were retrieved using a split- spoon sampler. When the auger first entered the stratum at 23 ft, it became harder to advance, and a sample was retrieved. As noted on the attached A&L Laboratory Soil Analysis Report, chemical analyses of the soil samples quantify several constituents that influence nitrate loading for this project. The important parameters for nitrate loading assessment are the organic matter, clay content, pH, cation exchange capacity(CEC), and the nitrate-nitrogen content of the soil. As noted,the organic matter is low, as to be expected. These O.M. concentrations suggest there is a small potential for future nitrate forming from organic matter. Because septic effluent is composed predominately of ammonium(NH4),the pH, along with the CEC, are significant influences on ammonium molecules. The pH of the soil is alkaline which may have a positive effect in promoting ammonia formation and not ammonium formation,which is the precursor to nitrate formation. The CEC measures the ability of the soil to theoretically trap and hold ammonium molecules. Cation Exchange Capacities of the soil samples illustrate a lower CEC of 6.0,4.5, and 7.4 meq/100 g,respectively,which was expected given the sand content of the soil samples. This suggests that the surface soils(3-10.5 ft depth)have a greater potential for the retention of ammonium molecules for plant root and microbial assimilation,thus the very low nitrate-nitrogen concentrations of 2 ppm. 2 Chesney Consulting