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INTRODUCTION Mr. Gutierrez and Ms. Manjarrez are proposing to construct a two-bedroom, single family residential (SFR) structure on the subject property referenced on the Title Page. The property is currently vacant, but previously contained a house and garage, and an onsite wastewater treatment system(OWTS), both subsequently demolished under San Joaquin County Environmental Health Department(EHD)permit. In addition,there is a domestic well which remains and will also be destroyed under EHD permit. AdvancedGeo, Inc. (AGI) submitted a Soil Suitability/Nitrate Loading Study(Project No. 20-6014, SR0082156) dated May 29, 2020 to the EHD. The AGI Study found the nitrate loading from the proposed development on the 0.23 acre Parcel to be 18.5 mg/L N; 8.5 mg/L N over the Maximum Contaminant Level (MCL)of 10 mg/L N. This Nitrate Loading Study report can be considered an Addendum to the AGI report and complies with the San Joaquin County Development Title Section 9-604.010(d)(1). Since the property is highly constrained due to its small size, Mr. Steven Shih, REHS, Program Manger for the EHD, is requiring a CA registered civil engineer(RCE)obtain all relevant data and information to: 1.) Determine if the proposed development will exceed the nitrate loading, using revised information, and 2.)Design an OWTS that will mitigate adverse effects to the onsite and surrounding domestic wells from any future percolating effluent from the subject property. In summary, soil testing has found the native soils at the proposed soil-effluent interface to contain a predominately silt(loam) soil material that possesses above average permeability at the 40" and 94" depths, but significantly decreases at the 268" depth. The nitrate loading standard has been determined to be acceptable through data acquisition and revisions, and engineering design criteria. There appears to be inconsistencies with the subject property lines. Consequently,the property should be surveyed to determine accurate boundaries so that accurate setbacks can be established. SOIL SUITABILITY INFORMATION Perc tests were conducted in the locations depicted on the Design Plans to assess the permeability of the proposed disposal area soils. Three borings were drilled with a B-24 Mobile Drill Rig at the 40", 94" and 268" depths. After drilling, 2" of pea gravel and 12 inches of water was placed in each boring. No standing water was observed in the test borings after the 24-hr pre-soak period. Consequently, EHD Perc Test Procedure#2 was conducted. Testing was done over a four-hour period to induce maximum soil saturation. A summary of the perc test results with corresponding application rates in gallons of effluent accepted per square foot of soil per day, are illustrated below in Table 1. Page 4- Chesney Engineering, Inc.