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Well Abandonment and Soil and Groundwater Investigation Work Plan <br /> US Can-Welty Road September 2007 <br /> borings. If no affected soil has been observed in adjacent borings,then soil samples will be collected <br /> from just above groundwater. <br /> At each boring location,risk assessment samples will be collected from either the most-affected soil <br /> within the 0 to 10 feet bgs interval,or from a depth of 5 feet bgs if no hydrocarbon impact is observed. If <br /> the most-affected soil is encountered below 10 feet bgs, then three intervals will be sampled: (1)the top <br /> 10 feet bgs for risk assessment,(2)below 10 feet bgs from the most-affected interval to assess the <br /> magnitude of COCs,and(3)beneath the affected soil to determine the vertical extent. However,if the <br /> most-affected soil occurs in the upper 10 feet bgs,then samples from the top 10 feet bgs may represent <br /> the most-affected interval and the risk-assessment interval. <br /> Soil Sample Analytical Procedures <br /> Soil samples will be submitted to Lancaster Laboratories,Inc. (Lancaster)in Lancaster,Pennsylvania and <br /> analyzed for the following CDCs: <br /> • TPHc, <br /> • BTEX,and <br /> • PAHs. <br /> A chain-of-custody form designating the soil samples to be analyzed and other information will <br /> accompany the samples to the laboratory. Soil samples will be analyzed for the COCs using the methods <br /> and sampling containers listed in Table 2. <br /> Collection of Grab Groundwater Samples <br /> If groundwater is encountered a grab groundwater sample will be collected,unless SPH or sheen are <br /> observed. If SPH or sheen on groundwater is observed,then a groundwater sample will typically be <br /> collected from other step-out borings in adjacent areas. <br /> Grab groundwater samples will be collected by placing a clean,pre-packed well screen through the rods <br /> of the Geoprobe®Dual Tube sampling system(or retracted hollow-stem augers)and extracted into <br /> containers using a peristaltic pump. After pumping begins,the pump flow rate will be adjusted to match <br /> the yield of the groundwater-bearing zone. The tubing end will be placed at the midpoint of the <br /> groundwater column in the boring to minimize the entrainment of sediment in the sample,the presence of <br /> which could artificially,upwardly bias concentrations of the COCs. The samples will be decanted into <br /> sample bottles in the following order: (1)BTEX,(2)TPHd, (3)PAHs,and(4)General Minerals. <br /> Groundwater Sample Analytical Procedures <br /> Groundwater samples will be collected from proposed borings SB-A through SB-K and monitoring wells <br /> MW-3 and MW-4 and submitted to Lancaster for analysis of the following COCs: <br /> • BTEX, <br /> • TPHd with and without a silica-gel cleanup, <br /> • PAHs,and <br /> • General Minerals(borings SB-E and SB-I). <br /> A chain-of-custody form designating the groundwater samples to be analyzed and other information will <br /> accompany the samples to the laboratory. Groundwater samples will be analyzed for the COCs using the <br /> methods and sampling containers listed in Table 2. Samples from borings SB-E and SB-1 will be analyzed <br /> for the General Minerals listed in Table 2 to evaluate the suitability of the uppermost groundwater for <br /> drinking water use. The General Minerals results may be evaluated in combination with available data <br /> from other nearby sites such as TAOC Ohm Pump Station and Vernalis Pump Station. <br /> 9 == <br /> mm/n/`. <br /> From Science to solations <br />