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Revised Work Plan – Mitigation of Trash and Debris from Private Property Site Private Property – 19133 East Liberty Road, Clements, California May 26, 2023 (Rev June 27, 2023) Project No. 21-899 4 3.2 EXCAVATION, SCREENING, VERIFICATION SAMPLING, STOCKPILING,TRANSPORTATION AND DISPOSAL All site activities will be performed in the presence of a San Joaquin County EHD representative. A medium sized excavator such as a caterpillar 330 or equivalent is proposed to excavate and screen the stockpiled materials currently containing a combination of trash, debris and soil. The trash and debris will be placed in a separate stockpile for off-site disposal and the remaining soil will be placed in a separate soil stockpile. The trash and debris stockpiled material will be directly loaded into dump trucks or stockpiled on-site. The trash and debris will be disposed of at an approved EHD disposal facility. Verification soil sampling will be performed following removal of trash and debris to establish that no remaining site soil is impacted with heavy metals, PCBs, SVOCs, asbestos or TPH exceeding residential and unrestricted land use screening criteria. The frequency of the verification sampling will be as follows: Sidewall and bottom of excavation samples will be collected at evenly distributed locations throughout the excavation based on the size and extend of each individual excavation, with the oversight and approval of the on-site EHD representative. The GPS coordinates of each confirmation sample will be recorded and displayed on a site plan that will also include the locations and dimensions of the sampled excavations. Refer to Table 1 below for the minimum sampling frequency of stockpiles staged at the Site. Stockpile samples collected for disposal purposes will be based on the size of the stockpiled material and will be as follows: For stockpiles ranging in size of 0 to 5,000 cubic yards, 1 sample per 250 cubic yards (CY) for the first 1,000 CY of material will be collected and 1 sample per 500 CY thereafter. For stockpiles greater than 5,000 CY, 12 samples will be collected and 1 additional sample will be collected per 1,000 CY thereafter. Laboratory analysis of stockpiled materials will ensure adequate characterization of all necessary exported materials for transport and acceptance to an off-site disposal/recycling facility. The source of the exported material, the associated laboratory reports for the exported materials and the information of the receiving facility will be provided in future correspondence. At the end of each workday all stockpiled material will be covered with plastic sheeting and secured with sandbags so as to not allow any material to be exposed to the elements and avoid human inhalation. At no point will any of the excavated soil be used on-site as fill material. All backfilled material will be sourced from a facility that provides soil analysis that meets the Department of Toxic Substances Control (DTSC) residential and unrestricted land use screening criteria.