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Sampling requirements shall meet all state and <br /> local implementing agency requirements and quality <br /> control specifications. <br /> During drilling, split spoon samples should be <br /> taker, at five-foot intervals or stratigraphic <br /> changes for geology definition. A hydrogeologist <br /> or soils engineer should by present to develop <br /> iithologic logs from sampling. Presence of <br /> hydrocarbon and water (using visual and odor <br /> techniques) should be noted and included with the <br /> .- boring logs. The contractor should obtain <br /> representative soil samples for storage at their <br /> office for a period of not less than thirty days. <br /> If allowable by local code, an undisturbed soil <br /> sample should be obtained from the site confining <br /> layer and analyzed for vertic&l permeability. soil <br /> samples from both the unconfined and confining <br /> µ layer should be taken as needed for convent nal <br /> soils testing (density, water content, grain size, <br /> Atterberg limits, etc.) . <br /> From this information, soils profiles in "it least <br /> two directions will be developed. Profiles should <br /> be summarized in a fence-type diagram to illustrate <br /> lithologic variations and contaminated areas. <br /> These profiles will be included in the assessment <br /> report to BP Oil. <br /> D. Water Table and Product Levels <br /> Monitor well top-of-casing elevations should be <br /> survi'yed to o.ol foot accuracy to a common datum'. <br /> Aftei well development and a three to ten day <br /> period for fluids stabilization, water level and <br /> product thickness measurements should be made. To <br /> confirm the presence or absence of free-phase <br /> product, product sample cuts should be obtaineri <br /> with a clear bailer. If possible, samples of <br /> _ product from the welle and from on site tankage <br /> -� should be collected by the contractor and analyzed <br /> by infrared spectroscopy, conventional petroleum <br /> analysis, and metals analysis to determine age and <br /> type. <br /> During the course of the Phase I investigation, <br /> additional water level and product thickness <br /> measurements should be collected to define seasonal <br /> variations and potential system impacts. <br /> Water-table elevations are plotted on a base maj? <br /> -. and contours fitted to the data to illustrate <br /> groundwater flow direction. significant amounts of <br /> --- .product--may-locally--depress- the water=table, and-7 - <br /> should be noted on map summaries. <br />