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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 6 Because the future site land use will be residential, the action level applied to the Site will be in accordance with the residential land use standards, Department of Toxic Substances Control Human and Ecological Risk Office (HERO) Human Health Risk Assessment (HHRA) Note 3 screening levels and residential screening levels established by the USEPA Region IX (2023). The residential soil screening level for lead is 80 milligram per kilogram (mg/kg) and all soil exceeding this level will be placed in a separate soil stockpile for removal. A total of approximately 4,000 to 7,000 cubic yards of trash and debris is estimated for removal, based in part on the field observations and soil sample results as presented in the Phase II site characterization report. Figure 3 presents access routes to follow in order to limit the amount of disturbance to neighboring sites. During excavation activities, water will be sprayed as necessary to suppress the generation of airborne particulate. Soil loads for off-site removal will be tarped to avoid loss of material during transport. After soil has been removed, based on soil quantities established from the prior site investigation, verification sampling will be performed to assess whether additional removals of impacted soils will be required. Extreme caution will be exercised to avoid damaging any utilities near or on the Site. 3.3 UTILITIES LOCATION The site activities will involve excavation and removal of trash and debris in the near surface soil. Verification soil sampling will provide data to support whether additional impacted soil requires removal. To safeguard subsurface utilities in the area of earthwork Underground Service Alert (Dig Alert) will be contacted prior to all excavation activities. Dig Alert will perform a standard site survey. The personnel from the various utilities will mark the location of their utilities with spray paint or by other means. If necessary, a geophysical survey will be conducted to accurately locate underground utilities in the vicinity of proposed excavations. 3.4 DUST CONTROL In accordance with the EHD environmental grievance documents and applicable regulations, this Work Plan along with the HASP proposes adequate precautions to avoid dust emissions resulting from the earthwork activities. Fugitive dust will be monitored during the field activities. Sediment control will be incorporated around excavation areas to limit sediment loading. A water mist/dust suppressant will also be applied to excavation areas and stockpiles as site conditions warrant.