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ERM Mike Quillid, CPESC, PMP, QSD 26 May 2023 Page 4 is observed and 1 foot below. Soil samples collected will be submitted on hold, pending analysis. If soil samples are collected, the following sample collection procedures will be followed: ■ Drill rods will be lined with single-use acetate or stainless-steel sleeves for soil sample collection. The sampling sleeves will be used to collect approximately 4-to 5-foot lengths of continuous soil samples. ■ The sleeves will be brought to the surface and opened lengthwise to expose the soil within. ■ Soil samples will be transferred from the acetate sleeve into laboratory-supplied jars, making every effort to minimize soil disturbance during the transfer. ■ Soil samples submitted for VOC analysis will include field preservation by United States Environmental Protection Agency(USEPA)Method 5035. To minimize volatilization losses, the samples will be collected directly from the acetate liner without further disturbing or reworking the sample. 4.2 Grab Groundwater Sampling The groundwater depth information obtained from the pilot soil boring will be used to determine sample depth for planned depth-discrete grab groundwater samples. Up to three groundwater samples will be collected from the groundwater interval identified in the pilot boring using Hydropunch (or equivalent)sample equipment. Hydropunch borings will be located as close as feasible to the existing excavation area around TC6S in a triangular pattern to adequately delineate groundwater near the excavation area (Figure 2). Groundwater sampling procedures are as follows: ■ After air knife utility clearance, a soil boring will be advanced with a direct-push drill rig. At the two locations not adjacent to the pilot boring, a soil boring will be drilled to collect continuous soil cores to top of the target water-bearing zone(e.g., if first encountered groundwater is at 10 feet bgs,then the soil boring will be advanced to 10 feet bgs).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 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 as described in Section 4.1 for the pilot boring. ■ The Hydropunch depth-discrete groundwater profiling technology advances a retractable stainless-steel sampling device into undisturbed soil ahead of the drill casing (i.e.,push-ahead technology). The sampling device and drive rods are sealed and water-tight. Upon reaching the target sample depth, the sampler is opened to expose the stainless-steel screen and sample chamberto the target water-bearing zone. The Hydropunch sample interval can vary to match the target water-bearing zone identified in the pilot boring. The interval will be no longer than 5 feet. ■ A peristaltic pump and tubing will be used to collect groundwater samples at the midpoint of the exposed screen. To the extent practicable, the Hydropunch sampler and casing will be purged priorto sampling to remove fines and induce groundwater flow from the formation. During purging,water level and groundwater parameters including turbidity,temperature, pH,