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Soil sampling will be conducted in accordance with ASTM 1586-84. Using this procedure, a sampler lined with plastic sample tubes is driven into the soil at approximately 5-foot intervals by a hydraulically operated hammer. Upon recovery, a portion of the soil sample will be placed in a plastic bag and sealed for later screening with an hNu type organic vapor meter (OVM). Another portion of the soil sample will be used for classification and description using the Unified Soil Classification System. One of the samples with no headspace present in the cylinder will be sealed in the plastic tube with Teflon® and a polyethylene cap, labeled, and stored at approximately 4 degrees C for prompt transport to the laboratory under chain-of-custody (COC) procedures. After the soil sample is placed in the plastic bag, it will be allowed to warm, inducing volatilization of petroleum hydrocarbon vapors. The headspace vapors will be screened with the OVM. The highest observed reading will be recorded on the boring logs. Borings that are not completed as wells will be abandoned by filling with cement/bentonite grout. The grout will be tremied or pumped into the borehole. 6.0 MONITORING WELL DEVELOPMENTIPURGING AND SAMPLIN Following installation, the wells will be surged with a surge block to remove fines from the and pack. After surging,ten casing volumes of ground water 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 and sampling event will be preceded by purging three well volumes as described above. After the water levels within the wells stabilize, samples will be collected with dedicated, clean, disposable plastic bailers. Samples will be contained in air-tight vials, checked for air bubbles as described above under "Groundwater Grab Samples", and then packed on ice and sent to the laboratory for analysis. Groundwater samples will be transported to the laboratory and analyzed within the EPA-specified holding time for requested analysis. 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 Califomia-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 will be 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 verify sample integrity and confirm that it was collected in the proper container, preserved correctly, and that there is an adequate volume for analysis. 7.0 GROUNDWATER DEPTH EVALUATION Depth to groundwater will be measured to the nearest 0.01 foot using an electronic hand-held water level indicator. The top of the probe will be examined to evaluate whether a product sheen is present. 8.0 SURVEYIN The top of each new well riser will be surveyed to allow correlation of the groundwater levels at the site. The surveyed point of each well riser will be marked to help insure future groundwater level measurements are taken from the same location. Elevations will be surveyed relative to the benchmark to the nearest 0.01-foot.