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i II. SOIL SUITABILITY STUDY FINDINGS A. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION SSS§ 1.1. The subject property has been a commercial property for more than 30 years and at one time, commercial businesses were tenants, including The Refuge Youth Center, Joint Heir Children's Church, Morada Cleaners, et al. Prior use decades ago was for agricultural production. Surrounding land use is Highway 99 and the Frontage Road to the east, commercial businesses to the north, and residential to the east. These residential subdivisions are OWTSs, and Wilkinson Manor MD 23 Pubic Water System, et al, as noted on the water map found in Appendix G. SSS§3.1,3.2,3.3,3.4,3.5,3.6,3.7, 6.8. It is well known that the Morada area is notorious for OWTS problems. Permit applications within the one-half mile radius study area from the property would be too numerous to itemize. Permits for the subject property are found in Appendix I. There have apparently been no permits issued for repair regarding the onsite systems. The soil percolation test results discussed below detail the permeability of the OWTS designed for this proposed project. As referenced,the disposal area will be installed in a narrow area between the existing building and the north property line. B. SOIL PHYSICAL CHARACTERISTICS AND ANALYTICAL TEST RESULTS The UC Davis Soil Web indicates the effluent disposal area soils to consist primarily of Jack-tone clay (4180), with 4%Archerdale, 3% Stockton, 3% Hollenbeck clays. SSS§5.2. The surface and subsurface soil investigation began on August 26, 2022. A 25 ft exploratory boring was drilled near the location of the proposed seepage pit installation. f NLS§ 1.1, 1.2. Soil samples for chemical and texture (particle size) analyses were retrieved from this exploratory boring at the 5 ft, 10 ft, 15 ft, 20 ft and 25 ft depths. As noted on the Laboratory Soil Analysis Report in Appendix D, chemical analyses of the retrieved soil samples was used to 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. The organic matter in the perc test borings are all normally low. Since the boring location has not been under agricultural production or landscaping, the nitrate-nitrogen concentrations under this area all have low nitrate-nitrogen concentrations of 3 ppm at 5 ft, and decreasing to 1 ppm at 10 ft. The pH of the soils is alkaline which may impede ammonium formation. The CEC ranges between a very low 4.9 to 18.4, illustrating the varying soil strata compositions. The higher CEC has a greater potential for adsorbing ammonium. The clay content of the soils indicates an ample percentage to promote biochemical processes, including the destruction of bacteria and viruses. j I Page -2- Chesney Consulting