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ERM Mike Quillid, CPESC, PMP, QSD 26 May 2023 Page 3 ■ A Site-specific Health and Safety Plan will be developed, including associated job hazard analyses for each specific work task. ■ Boring permits will be obtained from the SJEHD. Borings will be abandoned in accordance with County requirements and under supervision of an SJEHD inspector. ■ Boring locations will be marked in the field,and Underground Service Alert will be contacted at least 72 hours prior to initiating the work. ERM will coordinate with Underground Service Alert member companies to locate underground facilities in proximity to planned boring locations. ■ Each location will be cleared for subsurface utilities using a private utility-locating company and industry-accepted methodologies and tools. Drilling locations will be cleared in advance to at least 5 feet bgs using an air knife. 4. FIELD ACTIVITIES This section presents the scope of work that will be completed as part of the groundwater investigation. Figure 2 depicts proposed sampling locations to be completed underthis Workplan. The sampling approach and methods, analytical testing, and data evaluation procedures are described below. 4.1 Pilot Boring to Determine Groundwater Depth One pilot soil boring will be completed to first encountered groundwater(expected to be between 10 to 15 feet bgs)using a direct-push drill rig.The pilot soil boring will be collocated with one of the Hydropunch borings (Figure 2). After air knife utility clearance, the pilot soil boring will be advanced with a direct-push drill rig. The pilot soil boring will be drilled to collect continuous soil cores to first encountered groundwater (approximately 10 to 15 feet bgs). During direct-push drilling, soils will be continuously logged by an ERM field geologist, underthe direction of a California Professional Geologist in accordance with the Unified Soil Classification System. The field geologist will log the soil and identify saturated soil indicative of first encountered groundwater. If a suitable (generally medium-to coarse-grained)wet interval is not identified, drilling will continue in 5-foot intervals, up to a maximum of 25 feet bgs, until a suitable interval is identified. After drilling is completed at this borehole, it will be properly abandoned and a step-out boring will be completed for grab groundwater sample collection from the target zone. In addition to identifying first encountered groundwater, the soil core of the pilot boring will be screened to identify potentially impacted soil.To identify potential impacts, the soil core will be screened for odors and visual staining;and vapors will be measured with an organic vapor meter equipped with a photoionization detector(PID) using a 10.7-electron-volt lamp. Vapors will be measured using the PID by placing soil in zip-style plastic bags and measuring headspace concentrations. If petroleum contamination is observed in the soil core(either from visual observation or elevated PID readings), soil samples will be collected from thedeepestdepth interval where contamination