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INTRODUCTION Dennis and Nancy Souza are proposing to install a modular(manufactured) three 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 the engineering firm Terracon (Project No. NA207011), dated February 28, 2020 and submitted to EHD on March 5, 2020. 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 8.3 minutes per inch (min/in) for a shallow 3 ft depth and 20.83 min/in for a 10 ft test depth. The Study also noted the groundwater in this locale to be 110 and 120 below ground surface (bgs) in the Spring and between approximately 120 and 130 feet bgs in the Fall. The Nitrate Loading Study calculations found the resultant nitrate-nitrogen effluent concentration from this proposed project to be 34.5 ppm nitrate-nitrogen (NO3-N), which is 24.5 ppm over the Maximum Contaminant Level of 10 ppm NO3-N. Applicable Section (§) numbers of the San Joaquin County EHD Onsite Wastewater Treatment System Standards 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 1,500 gallon P&L Concrete, Inc. standard precast septic tank that is set with the inlet invert elevation 10 inches below existing grade. Tank size has been increased to accommodate potential surge flow(§7.1.2). This tank is to be situated in line with the influent tightline. The exit location from the modular home is unknown. In the second compartment of this tank, an Orenco Universal Biotube Pump Vault is to be installed. Within the screened pump vault is a duplex pump system. The pumps will alternate operations and will be set to timed dosing through the Orenco MVP Duplex Panel. Screened effluent is pressurized through a 2" line into a 2" manifold. Eight, 1" dia. laterals"T" connect to this manifold. Each lateral is 22 ft long, with a 1.0 ft long, 90°turn-up electrical sweeps at each distal end of the laterals with ball valves. These ends of the sweeps will be situated in valve boxes for easy access and will allow each lateral to be cleaned. Residual head is to be 5 ft. Page -1- Chesney Consulting