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Soil Suitability/ Nitrate Loading Study Addendum Letter Irerracon Proposed Global Carrier Inc. ■ Manteca, California July 24, 2019 ■ Terracon Project No. NA187034 Prior Report Review Based on a review of our Soil Suitability/Nitrate Loading Study dated August 8, 2018 prepared for Global Carrier, Inc. (Terracon Project Number: NA187034), the site consisted of an approximately 10.0-acre tract of land (APN 228-030-28) located at 11150 E. Highway 120, Manteca, San Joaquin County, California. At the time of the report, the site consisted of a residence, shop building, groundwater well, septic system, and almond orchard. The proposed development included removal of the existing almond orchard and construction of an approximately 8,000 square foot (SF) building to include a truck transfer dock, brake shop, storage area, tire shop, additional septic system, asphalt/concrete pavement, 142 parking stalls, stormwater retention basin, and limited landscaping. Based on conversations with Mr. Carlos Vieira, architect, the property will have a maximum daily usage of 157 gallons per day. Two San Joaquin County Environmental Health Department (EHD) permits, (Permit No. 71-334 and 77-1073) did not identify the septic tank size, construction, or number of leach lines. A repair performed in 1971 indicated one 60 foot long leach line was added to the existing septic system. One shallow (3.5 foot) percolation test was conducted on the eastern portion of the site resulting in a satisfactory percolation test rate of 22.7 minutes per inch. Soils consisted of silty sand to depths of 10 feet below grade surface (bgs). The nitrate loading calculation for the proposed truck facility was estimated to be 5.9 milligrams per liter nitrate (mg/L-N) and the development was not expected to cause a buildup of nitrates in the aquifer above the maximum contaminant level (MCL) of 10 mg/L-N. Elevated levels of Nitrate as N (13 mg/L-N) were detected slightly above the MCL in a groundwater sample collected from the onsite domestic well. Dibromochloropropane(DBCP)was not identified in the groundwater samples. Depth to groundwater was estimated between 30 and 50 feet bgs. Groundwater was not encountered in the soil borings to 10 feet bgs. Rainfall was estimated to be 2.86 inches per year. Average total nitrogen of the commercial effluent stream is 85 mg/L-N, rain concentration is 1.0 mg/L-N, and denitrification was 15%. There were no reported concerns with the existing residential septic system. Project Revisions Based on a review of a Site Plan dated February 8, 2019 prepared by Vieira Design Group and provided by Mr. Vieira, the site is proposed to be developed with a 13,100 SF truck terminal building to include a 4,800 SF tire and brake shop, 4,800 SF transfer dock, and 3,500 SF office, 29 standard parking stalls north the proposed building, 138 longer term truck parking stalls south of the new building, and 5 foot deep storm basin along the southern site boundary. Responsive■ Resourceful ■ Reliable 2