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C A M B R I A • A sensitive receptor(the mobile home park well)has been identified southeast of the subject site. The predominant shallow groundwater flow direction beneath the subject site has been toward the south-southeast. In order to be protective of the mobile home park well and in accordance with the groundwater flow direction, Cambria proposes drilling six soil borings located south, southeast,and east of the subject site to assess the lateral and vertical extent of 1,2-DCA. These borings will be drilled to 150 feet below grade (fbg), or until drilling refusal is encountered. Groundwater samples will be collected in coarse-grained zones identified in these borings. In addition, we propose installing a deep screened (-75 to 85 © fbg) well in the southeast corner of the subject property. The location of these borings and well are shown on Figure 2. • Cambria also proposes drilling three soil borings (SB-26, SB-27, and SB-28) north of the subject site to determine the source of, or the extent of the 1,2-DCA found in boring SB-18. The location of these borings is shown on Figure 2. • We are not proposing deep borings onsite near the source area at this time as we have learned through experience that assessing the vertical extent of contaminants by drilling through the source area can produce questionable data. Despite our best efforts to eliminate this possibility, it appears that drilling through shallow contaminants can introduce them to deeper zones during drilling or sampling activities, resulting in false positives or falsely elevated concentrations in the deeper zones. • At this time, we are not proposing additional deep screened wells (other than the one proposed in the southeastern corner of the site), as we need to determine the groundwater flow direction in the deeper zone in order to place the wells in the appropriate locations to monitor the 1,2-DCA plume. We presently have two quarters worth of groundwater flow data for the deep zone. The flow direction has been inconsistent (once toward the west and once toward the south-southeast). Once we have a better understanding of the deeper zone groundwater flow direction, and if additional wells are warranted, we will install additional deeper zone monitoring wells. • Cambria proposes installing two additional shallow zone wells on site to monitor 1,2-DCA in shallow groundwater. One well is proposed along the southern property line and the other is proposed along the eastern property line(Figure 2). 0797 3