ARCHIVED REPORTS XR0009954 - Laserfiche WebLink

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n& Working to Restore Nature that the influent TPHg concentrations ranged from 43,000 milligrams per cubic meter (mg/m3) from well VW-1 to 100,000 mg/m3 from well VW-4 (Table 2, Vapor Extraction Test Monitoring Data). Utilizing the vacuum and distance measurements obtained during the VET, RESNA estimated that a wellhead flowrate of 30 cfm and vacuum of 25 inches of water would result t in an effective radius of influence of approximately 25 feet The internal combustion engine influent and effluent vapor samples collected from extraction wells VW-1 and VW-4 indicated a destruction efficiency for benzene and TPI-Ig of greater than 94 percent. To remove residual hydrocarbons from historical capillary fringe soil and from other vadose zone regions beneath and near the USTs and to provide capture of sparge off-gas, we recommend that seven deep and two shallow vapor extraction wells be used This will require the installation of two additional deep vapor extraction wells (VW-11 and VW-12) The estimated limits of residual hydrocarbons in vadose and capillary fringe soil and the radius of influence for the vapor extraction wells are shown on Plate 5, Vapor Extraction Radius of Influence 15 to 40 Feet Below Grade and Plate 6, Vapor Extraction and Sparge Radius of Influence 40 to 60 Feet Below Grade Based upon the VET data, RESNA concludes that vapor extraction is a feasible method of remediating soil at this site 3_3 Air Sparge Test. On October 12 and 13, 1992, and December 22, 1992, RESNA conducted air sparge pilot testing at the site Testing performed on October 12 and December 22 consisted of sparging only, while testing on October 13 included combined sparging and vapor extraction The air sparging pilot test (RESNA, June 21, 1993) was performed to evaluate the feasibility of removing residual and dissolved hydrocarbons from the capillary fringe and saturated zone utilizing air sparging technology 30003-13 5