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March 10, 2003 NOA Enviromnental Project Number.LE03-063 Le Page 8 M. PROPOSED SITE INVESTIGATION Soil Sampling Locations LA A total of twelve (12) soil borings will be advanced on the subject property to gain a representative sampling of potential soil contamination. Approximate locations of these borings are depicted in L Figure 1; exact locations will be determined by the drilling crew on site. Four soil borings will be advanced in and around the former UST excavation site. Soil samples will be collected at intervals of five feet (5) beginning at a depth of 10.5 feet below ground surface. During the drilling process, soil samples will be analyzed for odor and discoloration. The soil borings will be terminated either at the first clay encountered or thirty feet (30')below surface grade. Two additional borings will be advanced adjacent to the existing in-use above-ground storage tank to a depth of five feet(5'). These borings will be advanced near the dispensers located on either side 9" of the tank. Two borings will be advanced to a depth often feet 10'near the existing truck wash as well. Four shallow borings not to exceed ten feet (10') will be scattered across the property at locations to be determined based upon field inspection; likely sampling locations are shown in Figure 1. The soil samples will be assessed in the field for the presence of odor and discoloration. At the discretion ofthe site supervisor, soil samples not remanded to the custody ofthe analytical laboratory will be collected and analyzed by field methods for the presence of petroleum hydrocarbons. This procedure will consist of emptying the contents of a tube sample into a"ziplock" style plastic bag. LA The bag and its contents will be placed either into direct sunlight or under an alternative heat source for a period of time. The bag will then be pierced and the "headspace"within tested for petroleum hydrocarbons compounds with a photoionizing hydrocarbon detection device. Soils will be classified in the field during the drilling operations. It is not expected that the boring will reach the level of groundwater beneath the site. Based on groundwater data available, regional groundwater is expected to be at a depth of 40 to 50 feet below ground surface. The condition of the site with respect to aquitards, aquicludes, and perched water zones is unknown. LA Drilling Methodology and Equipment Decontamination Procedures Prior to initiating the drilling operation,NOA Environmental will contact Underground Service Alert t.. (USA)in order to inform all public utilities that excavation and/or drilling operations would be taking place at the site. LN Prior to arriving at the site, all drilling and sampling equipment will be washed in a solution of trisodium phosphate (TSP) and dishwashing soap and water, and rinsed twice with tap water and once with deionized water. If cleaning is needed between samples, all drilling augers and associated