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r�� INTRODUCTION The preliminary physical and chemical testing of the soil and chemical analysis of the water table have been completed for the proposed domestic wastewater effluent disposal areas associated with each Building referenced on the Title Page. The soil physical testing consisted of percolation testing along with soil chemical testing for factors that influence nitrate loading. Additionally, water table samples were retrieved to also determine nitrate loading factors and constituents. This data and information will be used in the Nitrate Loading/Soil Suitability Studies required by the San Joaquin County Environmental Health Department(EHD) for this project. These test results and water table determinations will also be used in the final effluent disposal design by Siegfried Engineering, Inc. for each Building. Testing was conducted in the months of February and March of this year during one of the wettest rainy seasons on record. Because of the closely intermittent rainfall events and intensity,perc test scheduling was very challenging. The soils maintained moisture contents that could be considered well above field capacity, but below saturation. Consequently, the perc test procedures of inducing soil saturation were readily achieved at the beginning of each test. FINDINGS Testing protocol for this project began near the proposed effluent disposal location to serve Building E&E (a.k.a. Building J) on February 25,2019. Two separate percolation tests were drilled to different elevations, as noted on the attached Percolation Test Rate data sheet. Both perc tests were conducted in a silty clay loam (USCS silty clay- SC) soil structure. At the 24" perc test depth, which was conducted just 7.56" above the water table and within the capillary fringe,there remains permeability with a perc rate of 83.3 minutes/inch(min/in). Although this is a comparatively slow rate, a much slower rate would have been expected. Technically,this rate is considered failing by EHD since it is slower than 60 min/in. However, since all the wastewater treatment and disposal systems for this project will be engineered, under Section 7.1 of the SJC EHD Onsite Wastewater Treatment Systems Standards, failing rates can still be used for civil engineering design purposes. i Analysis of the groundwater under the disposal area for Building E&E, finds a high concentration of nitrate from past on-site organic recycling operations. This nitrate determination will be addressed in the Nitrate Loading Study for the E&E Parcel and project. The second E&E perc test was conducted at a depth of 36" and at a 3.65' higher elevation(test depth=2.65' higher) directly east of the 24" perc test, as noted on the attached perc test locations map. It is my understanding that this is near the elevation where the proposed disposal area is to be constructed for Building E&E. Test results reveal a slow but passing perc rate at 50.0 min/in with the same soil structure at test depth as in the 24" deep perc test and conducted well above the capillary fringe. The second testingprotocol began on March 19 for the south test locations for Buildings A and B. p g g Perc test result for B-S (Building B, South)had a final perc rate of 41.7 min/in. Page 1 of 3 Chesney Consulting