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The composite characterization samples will be collected from the stockpiled soil by . # i selecting random locations accessible around the soil pile, removing approximately six inches of soil, and driving a clean brass sleeve into the soil pile at the selected location. The number of samples collected will be based on the estimated amount of stockpiled soil. Generally, one composite soil sample is collected per 50 or 100 cubic yards of soil. The samples collected will be prepared and chilled for transport under Chain-of-Custody protocol, and sent to a State-certified laboratory for the analyses requested. 4.0 GROUNDWATER DEPTH EVALUATION Depth to groundwater will be measured to the nearest 0.01-foot using an electronic hand- held water level indicator. The tip of the probe will be examined to evaluate whether separate-phase hydrocarbon (SPH) sheen was present. 5.0 MONITORING WELL DEVELOPMENTIPURGING AND SAMPLING Following installation, the wells will be surged with a surge block to remove fines from the sand pack. After surging, groundwater will be purged from each well using a bailer or centrifugal pump to remove sediment and enhance representative sample quality. Groundwater sampling events conducted after the initial well development will be preceded by purging a minimum of three well casing volumes as described above. Purge water will be monitored for the parameters temperature, pH, and conductivity until stabilized. Wells will be allowed to recharge to 80% before sampling. If wells dewater, they will be allowed to recharge for a minimum of one hour prior to sampling. After the water levels within the wells stabilized, a sample will be collected with a clean disposable bailer. Samples will be contained in air-tight vials, packed on ice, and transported to the laboratory for analysis. Groundwater samples will be transported to the laboratory and analyzed within the EPA-specified holding time for requested analyses. Each sample container submitted for analysis will have a label affixed to identify the job number, sample date, time of sample collection, and a sample number unique to that sample. Samples will be analyzed by a California-certified laboratory A Chain-of-Custody form will be used to record possession of the sample from time of collection to its arrival at the laboratory. When the samples are shipped, the person in custody of them will relinquish the samples by signing the Chain-of-Custody form and noting the time. The Sample Control Officer at the laboratory will then verify the sample integrity and confirm that the sample was collected in the proper container, preserved correctly, and that there is an adequate volume for analysis. 6.0 WELLHEAD TOP OF CASING MEASUREMENT The top of each new well riser will be surveyed to allow correlation of the groundwater levels at the site. The surveyed point on each well riser will be marked to help insure future groundwater level measurements are taken from the same location. All measurements will be surveyed to the nearest 0.01-foot relative to a surveyed benchmark for Global Positioning System (GPS) locations (X and Y coordinates) and elevations (Z coordinates). Project No. 1463-11 B -2 HORIZON ENVIRONMENTAL INC.