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Privileged and Confidential, Attorney Work Product June 22,2018 Scope of Work for 455 E.Eleventh Street,Tracy,CA 95376 of approximately 12.5 to 13 feet bgs to assess deeper soil impacts from potential leaks from the former UST.The sample will be submitted to the laboratory for lead,VOCs, CAM 17 metals,TPH-g,TPH-d and TPH-mo. Task 1.2 Soil-Gas Sampling To supplement the existing data set, additional soil-gas samples at depths of 5 feet bgs and 10 feet bgs will be collected in the immediate vicinity of the former UST at location SG4. The boring will be drilled by a licensed drilling subcontractor using a hand auger, dual-tube, direct push (or equivalent) drilling method.The soil-gas samples will be collected following Department of Toxic Substances Control(DISC)approved methods' . The soil-gas sample will be collected in laboratory-provided SUMMA canisters and will be transferred under strict chain-of-custody procedures to a California-certified analytical laboratory.The samples will be analyzed for volatile organic compounds (VOCs) using EPA Method TO-15 and TPH-g using method 8260B and Helium using ASTM Method D1946-90. Task 1.3 Groundwater Sampling To assess potential impacts to groundwater from the former gasoline UST at the Site, grab groundwater samples will be collected from three additional locations shown on figure 1.The groundwater samples will be analyzed for TPH-g,VOCs,TPH-d,TPH-mo and lead. The boring will be advanced to the depth of groundwater(estimated to be approximately 10 feet bgs), or a maximum of 20 feet bgs. If groundwater is encountered, a grab groundwater sample will be collected from the inside of the boring, using a clean disposable bailer or disposable tubing and either a peristaltic pump or check valve pump. A temporary PVC well screen may also be installed if necessary to allow removal of the duel tube rods, in which case the sample will be collected from inside the temporary casing. Closing We are grateful for the opportunity to offer our services on this important project. If you have any questions or comment regarding this proposal, please contact Andy Lojo at(510) 645 1850 ext. 77 or Wendy Bellah at(510) 645-1850 ext.83. Sincerely, Andrew M. Lojo, P.G. Wendy Bellah Principal Geologist Senior Associate Engineer Attachments Figure 1—Proposed Additional Sample Locations 1 California Environmental Protection Agency(Cal/EPA).2015.Advisory:Active Soil Gas Investigations.July. Page 3 of 3 Terraphase Engineering Inc.