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1 <br /> PES Environmental,Inc. <br /> Ms. Emily Cushman <br /> November 24, 2015 <br /> Page 5 <br /> Groundwater Sampling Methodology <br /> Temporary Well Installation and Sampling <br /> Once soil samples are obtained, each borehole will be converted for groundwater sampling by <br /> installing a temporary well. The temporary well will be constructed using nominal 0.75-inch <br /> diameter PVC blank and well screen or pre-packed well screen. The depth of the screened <br /> interval will be determined based on field conditions such that it intersects the top of the <br /> saturated zone in each boring. <br /> Groundwater samples will be collected from inside the PVC casing using either a small <br /> diameter disposable polyethylene bailer, peristaltic pump or check valve with polyethylene <br /> tubing. The grab groundwater samples will be immediately decanted from the bailer or tubing <br /> into appropriate laboratory-supplied sample bottles, which will be slowly filled in a manner <br /> to minimize sample disturbance and potential headspace or air bubbles in the sample bottle. <br /> Field duplicates and trip blanks will be collected or utilized for quality control purposes. <br /> As stated above, filled sample containers will be labeled for identification and immediately <br /> placed in a chilled, thermally insulated cooler (containing either bagged ice or blue ice) until <br /> delivery under chain-of-custody protocol to the project laboratory. Each groundwater sample <br /> will be assigned a sample number that will be entered on the chain-of-custody form. The <br /> chain-of-custody form will accompany the sample shipment to the laboratory to document <br /> sample possession from the time of collection. <br /> Chemical Analysis Program for Groundwater <br /> Groundwater samples collected during the investigation will be analyzed for TPHg, BTEX, <br /> MTBE, TBA and naphthalene by U.S. EPA Method 8260B. <br /> DATA EVALUATION AND REPORTING <br /> Upon receipt, PES will compile the field observation data and soil and groundwater analytical <br /> results to better assess the extent of hydrocarbon-affected soil and groundwater. A report will <br /> be prepared which: (1) documents sample collection methodologies; (2) provides the results <br /> of PES' evaluation with tabulated analytical data and a graphical presentation of the soil and <br /> groundwater data; and (3) recommendations for further investigation, if warranted. Support <br /> documentation, such as boring logs and laboratory reports, will also be provided as appendices <br /> to the report. <br /> 148400101W003.doex <br />