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Ms. A Kolata August 14, 2012 Page 4 of 9 IDEM correspondence. To maximize efficiency, potential impacts will be characterized by advan ing a series of soil probes using a Geoprobe. Soil samples will be sampled continuously from each soil probe and field screened using a photoionization detector (PID) for the presence of contaminants associated with petroleum. Seven soil probes will be advanced as shown on the two attachments. Each soil probe will be advan ed to the water table (anticipated to be approximately 25 -30 feet). Soil samples will be collected and field screened for the presence of volatile organic compounds (VOC) by using a photoionization detector (PID). Unsaturated soil samples with the highest PID levels at the each boring locations will be submitted to an analytical laboratory for analysis of the following parameters: TPH GRO, TPH ERO, VOCs (including BTEX and MTBE), PNAs (inclu ing naphthalene), and lead as specified by the IDEM. By using a hollow stem auger rig, each soil probe locations will be converted to 2 -inch diameter monitoring wells constructed of PVC casing. The top of each well will be completed flush with the ground surface. Top of casing elevations will be surveyed. Ground water elevations will be measured in each well in addition to the three existing wells and a general groundwater flow direction will be determined. Each monitoring well will be constructed in accordance with general accepted construction standards and IDEM regulations. Ground water samples will be collected upon well completion and purging and submitted to an independent laboratory for analysi3 of the following parameters: VOCs, PNAs, total lead, and dissolved lead. Samples will also be collected from the three existing monitoring wells. For cot estimating purposes, we have assumed that the 6 soil samples and 9 ground water sample will be submitted for analysis. To support a possible closure for this site, Level IV data quality objectives (DQOs) will be met. The IDEM requires the collection of various quality assura ce /quality control (QA/QC) samples be collected during site characterization to ensure properl sampling and analytical techniques are being followed. These include a matrix spike/rnatrix spike duplicate (soil and water), equipment blank, field duplicate (soil and water), and trip blank (water). Weaver Boos estimates that an additional three soil samples and four water samples will be required to comply with QA /QC requirements. The actual number of analyses or parameters for this entire project might require modification based upon conditions encountered in the field and the laboratory analytical results. Any modification to the proposed analytical sampling program as outlined in this task or subsequent