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Progress Report on Tatum House Subsidence issues <br />April 12, 1995 <br />Page 2 <br />There are a couple of examples of problems that have been noted on these maps. <br />j <br />1 <br />While working with Mr Baldwin on subsidence issues relating to the Golden Eagle <br />Mine on his property across the highway from yours, we obtained a copy of the <br />MSHA map dated November 23, 1993. There was a 300 ft. + error in plotting the <br />surface political subdivisions with respect to the mine workings. This error was <br />subsequently corrected, and in fact section lines have been completely eliminated <br />from the copy of the map that was given to you by OSM. <br />There is a 1 in. to 100 ft. scale photobase map made by the City of Trinidad along <br />their water supply line in the Purgatory river valley. Sheet 11 includes the Tatum <br />house. The distance from the inside point of the "L" of the Tatum house to the <br />railroad is scaled to be 695 ft. The distance scaled on the 1 in. to 400 ft. scale MSHA <br />map is 715 ft., about the same as the 1 in. to 500 ft. scale permit maps. A NAPP <br />1:40,000 aerial photo (No. 6672-72) flown 6/30/93, was scanned, the image w•as <br />zoomed to 833x and the distance was scaled by computer to be 696 ft. The <br />conclusion is that the house may be at least 20 ft. closer to the mine workings than <br />the distance used in the evaluations to date. <br />WOODWARD-CLYDE CONSULTANTS STUDY <br />In 1981 the Department of Energy Contracted a study of the "Characterization of <br />Subsidence over Longwall Mining Panels", to Woodward-Clyde Consultants of San <br />Francisco California, Contract No. DE-AC22-80PC30117. The report is dated <br />September 19, 1982. This study was conducted at the Allen Mine (Golden Eagle) <br />near Weston, CO. I borrowed a copy of his report from the Denver office of the U S <br />Bureau of Mines. <br />The purpose of this study was part of a program conducted by the Department of <br />Energy to develop a relevant data base of information to improve subsidence <br />prediction techniques in each of the major coal fields in the United States with the <br />intent of perhaps expanding coal production. The Allen Mine was chosen as <br />representative of the Rocky Mountain Coa] Province. <br />The study consisted of establishing surface and underground monitoring points on <br />two coal mining panels one of which was a ]ongwall panel and the other included <br />room and pillar data. Baseline measurements were made 12/17/81 and final <br />readings were taken 5/5/82. The study was terminated 2 years earlier than planned <br />because of a cancellation of the program by DOE, and although the project was <br />turned over to the USBM, it was never funded. <br />