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INTRODUCTION Mr. & Mrs. Luis Ramirez are proposing to construct a three bedroom, single family residence (SFR) on property they own, as referenced on the Title Page. The San Joaquin County Environmental Health Department (EHD) required a Soil Suitability Study and Nitrate Loading Study for this project. These Studies were completed by AdvancedGeo (Project No. AG 22- 6747), dated February 15, 2022 and submitted to EHD (SR0084919). The findings from the Soil Suitability Study indicate the soil underlying the property is suitable for the acceptance of onsite wastewater treatment system (OWTS) effluent because of an • acceptable percolation rate of 13.2 minutes per inch (min/in). The Study also noted the groundwater in this locale to be 20 to 25 below surface grade (bsg). Consequently, the 8 ft separation distance between the soil-effluent interface and the water table can be easily achieved. However, the Nitrate Loading Study calculations found the resultant nitrate-nitrogen effluent concentration to be 16.28 ppm nitrate-nitrogen (NO3-N), which is 6.28 ppm over the Maximum Contaminant Level of 10 ppm NO3-N. The March 17, 2022 directive letter from EHD states in Section lb. of this document, that the potential impact of the nitrate to ground water shall be mitigated. To mitigate the excessive nitrate loading (as calculated) from the proposed OWTS, the following investigative and design parameters are presented for this project in three different Sections. Each lettered parameter summarized below is detailed in the following Sections and discussed in greater detail in the Conclusions Section: Soil samples were obtained to assess soil characteristics affecting nitrate loading. The effluent disposal structure has been designed as a filter bed, with a relatively shallow soil cover to promote oxygen intrusion. The effluent will be dispersed under gravity throughout the filter bed achieving relative equal distribution. A sump structure has also been added to the filter bed design, as illustrated on the attached engineering plans (Appendix D). A different parameter was used in the re-calculation of the nitrate loading concerning rainfall, thus lowering the theoretically predicted nitrate loading impact to below the Maximum Contaminant Level (MCL). OWTS DESIGN - PARAMETERS AND OPERATIONAL COMPONENTS Section A: Two soil samples were retrieved from under the proposed filter bed location from the 20-24 inch depth and the 42-48 inch depth. These samples were obtained to determine constituents of the soil that influence nitrate loading. Page -1- Chesney Consulting