Source Zone Delineation Demonstration Report - Triad Resource ...

6.3 SummaryA cost comparison summary for each of the hypothetical investigative approaches is shown in Table 6-5.The two conventional investigative approaches are the most expensive, primarily because both includetwo phases of field activity separated by a data evaluation and reporting task. The HSA investigationincurs a very high cost associated with the disposal of IDW because of the comparatively larger diameterauger used to advance the boring for sample collection. However, HSA may be the most versatile of theinvestigative methods considered in this analysis due to its ability to penetrate through gravels andcobbles and the ability to complete a well following soil sampling activities.Adaptive investigations reduce investigative costs and eliminate the need for multiple phases of fieldworkseparated by weeks of sample analyses time. This is achieved through the use of on-site analyticalcapabilities and data evaluation being conducted concurrent with data acquisition. New samplinglocations are selected adaptively based on the evaluation of all previously acquired analytical data.The WS/DSITMS investigation is the most costly of the adaptive investigative techniques, but also resultsin the most detailed model of soil contamination in the vadose zone. The advantages of SVE/DSITMS asa characterization tool are the relative ease and low-cost of implementation, the large volume of theunsaturated zone affected, and the extensive amount of data collected as compared to soil borings. Eachstep test investigates a large volume of the unsaturated zone and can provide pneumatic data pertaining tothe vadose zone, including radius of influence and bulk in situ air permeability for each vent well. Anancillary benefit associated with a SVE/DSITMS investigation is the potential to substantially remediate asource zone while characterizing it.March 2003 6-11 OU 12 Demonstration ReportFinal