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-Jon 6 19 5 4 16PM IEG TECHNOLOGIH No 2615 P 7/31 <br /> 95-WP 103 05 <br /> "CAPTURE ZONE" COMPUTATION <br />. The UVB creates a complex, three-dimensional groundwater circulation cell with a flow pattern having <br /> a vertical component in addition to horizontal flow The UVB "capture zone" and size of the three- <br /> dimensional groundwater circulation cell have been estimated using equations and graphical solutions <br /> developed over several years by Dr. Bruno Herrling of the Groundwater Research Group, <br /> Hydromechanics Institute, University of Karlsruhe, Germany A discussion of the geometry created <br /> around a UVB and the assumptions used in the model is provided to Herrlm& at al (1991) <br /> Based on the following hydraubc parameters and well specifications, the upstream and downstream <br /> stagnation points,the distances B$ and BT and cross-sectional UVB "capture zone" area, and the spacing <br /> requirements for additional UVB"s have been estimated. <br /> i = 0 007 (hydraulic gradient) <br /> kz — 4 3x10" m/s (horizontal hydraulic conductivrty) <br /> kv = 4 3x10 m/s (vertical hydraulic conductivity) <br /> V = 3x10' m/s (Darc:an velocity) <br /> H — 13 72 in (thnckmss of treatment zone) <br /> Q — 5 m3/hr (discharge through the UVB) <br /> a r = 4 2 m (length of upper screen section) <br /> as = 3 6 m (length of lower screen section) <br /> Using the corresponding dimensioning diagrams from Herrhng et al, the following values were obtained <br /> for the UVB at Site 31. <br /> S = 34 3m (112 iL) (distance to the upstream and downstream stagnation points <br /> from the well axis) <br /> BT -- 27 4m (90 ft.) (capture width at the top of the aquifer) <br /> BB = 106 3m (349 ft.) (capture width at the bottom of the aquifer) <br /> A — 1,176m� (12,660 fL. (cross sectional area of UVB "capture zone") <br /> D = 72m (236 ft.) (predicted spacing distance between UVBs for most <br /> effnciem plume capture) <br /> The width at the top and bottom of the capture zone is calculated for a distance five times the stagnation <br /> point upstream of the UVB In plan view, the radial distance of the circulation cell perpendicular to flow <br /> is calculated using the equation BT+B6/4 This equation yields a plan view radial distance for the <br /> circulation cell of approximately 110 feet. The result of this analysis is shown on Figure 4 <br /> MON rOR]NG AND SAMPLING PROGRAM <br /> The momtonng and sampling program designed to generate data necessary for evaluating the treatment <br /> effectiveness consisted of the following major elements- <br /> Pilot boring and soil sampling <br /> Baseline (pre-startup) groundwater sampling <br /> • Operational monitoring. <br /> Air monitoring and sampling <br /> 5 <br />