SITE INFORMATION AND CORRESPONDENCE

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Geomairix Consultants October 14,2003 Page at 5-foot intervals along east-west-traverses spaced 10 feet apart,extending to within approximately 10 to 20 feet of above ground obstructions. The subsequent TC limits are shown on Plate 2 for ' reference ("Limits of Terrain Conductivity Survey"). The EMLL and MD instrumentation were operated on a 50-by-50-foot and 10-by-10-foot grid,respectively,with fill-in traverses as needed. ' The EMLL and MD methods are subject to less interference from above ground debris than the TC ' method,thereby allowing investigation ofthe smaller areas among brush cover and closer to adjacent debris,where observance of a representative TC background response was not possible. I ,. Following data collection,we generated a preliminary TC contour map in the field and reviewed it to identify TC variations (anomalies) indicative of unknown sources, including possible utilities. In general, TC variations indicative of utility alignments are typically represented as numerous closely spaced herring-bone shaped contours or closely spaced parallel contours. A lack of contours 1: indicates an absence of utilities or if utilities are present, that they are beyond. the detection capabilities of the TC method. Completion of the investigation with the EMLL and MD methods ' allowed us to more definitively resolve the utilities detected with the TC method, to search for potentially smaller diameter or differently constructed lines that may not have been indicated by the TC data, and to locate potentially shorter utility segments than were identified by TC results. Since the EMLL and MD instruments do not record data,the surface traces of detected utilities and buried metal were marked on the ground surface with spray paint as the scanning was performed. ' RESULTS l The final results of the geophysical investigation are presented on Plates 1 and 2, the geophysical z survey map and the TC contour map,respectively. The TC contour map includes both the coordinate axes and the specific limits of the TC survey. It also shows the variations in terrain conductivity within the survey area and the locations,of suspected utilities,relative to the site features from Plate �= 1. The geophysical survey map (Plate 1) shows the locations of all interpreted items, our grid point reference stakes,and above ground cultural features in closeproximity to the site. Based on the TC, EMLL, and MD results,we have interpreted the location of more than 40 potential utility segments within the limits of the investigation area. We also have located several areas of buried metal. A �i discussion of these results follows below. Utilities The detected utilities are shown with dashed lines on Plate 1. These include mostly undifferentiated 1' utilities(uu),the majority of which appear to abruptly terminate at various locations within the site (shown with a"—"symbol). In some cases,the utilities may actually continue past these points,but were no longer detectable due to an increase in depth, extreme corrosion, above ground obstacles c:z 1