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INTRODUCTION Janet and Javier Leon are proposing to install a modular(manufactured) two bedroom home on property they own,referenced on the Title Page. This proposed modular home is considered a Second Unit Dwelling by San Joaquin County. The San Joaquin County Environmental Health Department(EHD)required a Soil Suitability Study and Nitrate Loading Study for this project and all projects where exceedance of nitrate loading standards may occur. These Studies were completed by Advanced GeoEnvironmental (Project No. AGE-19-4881), dated October 23, 2019 and submitted to EHD on November 5, 2019 (SR0081371). 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 20.8 min/in; correlated with an application rate of 0.643 gals/sf/day. The Study also noted the groundwater in this locale to be 20 to 25 below surface grade(bsg). The Nitrate Loading Study calculations found the resultant nitrate-nitrogen effluent concentration to be 14.96 ppm nitrate-nitrogen(NO3-N),which is 4.96 ppm (1.5x) over the Maximum Contaminant Level of 10 ppm NO3-N. In reference to the depth of groundwater as discussed in the Advanced GeoEnvironmental document: Depth to Groundwater Maps published by the San Joaquin County Public Works Department for the year Spring 1999 illustrate the depth to groundwater was approximately 10 bsg. The 1983 Groundwater Map depth to Groundwater at the subject property is indeterminable, but the water table elevation may be assumed to be comparatively flat due to its proximity to the Delta. This would also place the groundwater depth at 10 ft bsg. This depth can be assumed to be the"highest anticipated depth to groundwater." Unless there is highly significant rainfall concurrently for several years,this shallow depth is unlikely to ever be observed again due to over-pumping of the groundwater. Applicable Section(§)numbers of the San Joaquin County EHD Onsite Wastewater Treatment System Standards for an engineered system (Section 7, et al) are noted within this document. O.W.T.S. DESIGN- OPERATIONAL COMPONENTS AND PARAMETERS The following is an overview describing the operational design: The OWTS design begins with a 1,200 gallon P&L Concrete, Inc. standard precast septic tank that is set with the inlet invert elevation 10 inches below existing grade. Potential surge flow is easily accommodated with this tank size given the modular home is a small, two bedroom structure (§7.1.2). This tank is to be situated in line with the influent tightline. The influent line exits the modular home at the east end of the structure. Page -1- Chesney Consultin;