ARCHIVED REPORTS XR0001765 - Laserfiche WebLink

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Cambria Environmental Technology, Inc. September 25, 2001 Page 2 interference. These two areas were the hedge area south of the bank building and the aisles under the canopy area. Task 2 We established a survey grid to guide the TF magnetic data acquisition. The grid consisted of north-south lines spaced 10 feet apart with paint marks at 5-foot intervals. Task 3 Following the grid set-up, we used a proton precession magnetometer to collect TF magnetic data at each of the paint marks. We then up-loaded the data to a field computer and processed them to produce a preliminary total field magnetic intensity contour map. This contour map was evaluated for localized magnetic variations (anomalies) that may be due to possible UST's or other similar buried ferrous objects. Task 4 The MD method was used to perform site-specific investigations of suspect areas identified on the TF contour map. This involved multi-directional traverses, approximately ten feet long spaced approximately 1-foot apart, centered on suspect areas. Task 5 We then used the MD method to conduct a reconnaissance of selected broader portions of the site. i Task 6 We obtained GPR profiles in suspect areas. These profiles were then evaluated for evidence of UST-like objects. Task 7 The last task undertaken in the field was to map the locations of above ground cultural objects and suspected buried features. RESULTS The results of the geophysical investigation are presented on Plates 1 and 2. Plate 1 is a generalized site map showing the locations of above ground features; the limits of the investigation area; the locations of suspected buried objects; and the locations of the GPR traverses. Plate 2 is a TF contour map depicting the distribution of TF values, the location of pertinent above ground objects which are believed to affect the TF values, and interpreted buried features. Based on our interpretation of the data presented on Plate 2 and the results of the metal detector survey, our conclusions for this site can be summarized as follows: The tightly spaced and convoluted TF contours evident on Plate 2 indicate the presence of notable amounts of ferrous metal. This is especially true in the canopy portion of the investigation area. While some of these anomalies can be attributed to the effects of known metallic objects, the majority of the anomalies are believed to be caused by buried metallic . debris. None of the TF anomalies are typical of those caused by UST's. r�