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<br />Mr. H. Bruce Humphries <br />November 7, 1996 <br />Page 2 <br />Summary of Field Investigation. On Tuesday, September 24, 1996, as per our meeting with the <br />Division of Minerals and Geology ("Division") on September 5, 1996, and our letU;r to you dated <br />September 12, 1996, EFN implemented the following approach to determine the p~:rcent uranium <br />content of the waste rock and low-grade ore at the Sunday and West Sunday Mines: <br />Using a calibrated probe which measures beta and gamma emissions, take measurements <br />at 100-foot grid spacings on the Sunday and West Sunday Mine dumps. <br />The probe was field-calibrated to a known ore standazd of 0.19 percent, so measurements <br />were convertible to ore percent uranium values. <br />QA/verification samples were collected at five sampling points, for analysis for uranium <br />content by an independent contract laboratory. <br />This survey/field investigation is consistent with the WDEQ/LQD Guideline. <br />Additionally, EFN has had extensive experience in conducting these surveys in the context of <br />both premising and post-closure characterization of mine sites and other ore storage locations. <br />This experience adds to our confidence in the results of the field survey at the Sumfay properties. <br />The field work was observed and recorded by James Dille, an inspector from the Division, <br />who was joined part way through the morning by Robert Kershaw, from the Bureau of Land <br />Management, Durango. EFN personnel included Richazd Van Horn, Manager of Plateau <br />Operations; Michelle Rehmann, Environmental Manager; and Jim Fisher and Harley Gardner, <br />Dove Creek staff members. Mr. Fisher and Mr. Gardner calibrated the probes, and each took one <br />measurement at each designated sampling point. Mt. Dille assisted in randomly selecting <br />sampling points to be used for collection of laboratory QA points. <br />Field measurements are shown on the attached copies of actual maps used in the field for <br />recording the field measurements (see Attachments 1 and 2). The sample points aze designated <br />by grid locations. A table summary of the field data, including average percent uranium content <br />for the Sunday waste dump, the Sunday low-grade pile, and the West Sunday vvaste dump, is <br />included as Attachment 3. Five samples were collected at randomly selected points (D-15, F-15, <br />G-2, BB-4, and DD-3) and sent to Energy Laboratory in Casper, Wyoming for analysis of percent <br />uranium content. The analytical results aze included as Attachment 4. <br />The laboratory was provided sample bags containing at least one liter of materials ranging <br />in size from sand to approximately 2"d rocks. The laboratory crushed the sample;> and analyzed <br />10 grams from each sample. This selective analysis of only a portion of the sample, together <br />with the differences in measurement of the uranium contents of all the rock surrounding the probe <br />in the field vs. analyzing only a sample of rock at the laboratory, produced results which are <br />within 0.001 to 0.054 percent uranium content of U,OB field-measured values. V/hile it should <br />