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Ill IIIIIIIIIIIII III ~ ~ - . ~ ~~ ~. United States Department of the Interior OFFICE OF SURFACE MINING Rcdamauon and Fnforcanrnt 1999 Brwdway, Suiu 3320 lknvcr. Colorado 80202-5733 AUG - 11995 Mrs. Ann Tatum Jim Tatum & Associates 8703 Bonhomme Houston, Texas 77074 Dear Ms. Tatum: RECEIVED AUG 0 4 ~ggg JIVI51on or minerals tS 1ie010gy I am writing in response to your July 13 and July 18, 1995 letters asking the Office of Surface Mining Reclamation and Enforcement (OSM) to conduct additional analysis and raising concerns about information in previous correspondence. Let me respond first to your concerns regarding my June 21, 1995 letter to Senator Grarrtm: The matter of alleged subsidence to your home was investigated by three OSM personnel trained and experienced in mine-related environmental issues, one of whom you specifically requested by name. He and the other two investigators found no mine-related damage to your home. The three.reports prepared by these specialists have been sent to your office. The June 21 letter to Senator Gramm stated that the mine area was located 300-500 feet from your house, rather than 500 feet, as you contend. Your letter of July 13, 1995 referenced movement recorded along the railroad tracks. Several years ago when full extraction was contemplated in the first north panel, the Colorado Division of Minerals and Gcelegy (DMG) required subsidence monitoring points to be established. These monitoring points were set in the proximity of the railroad tracks south of your home. Two of these points were located directly over the proposed mined-out area (IN-I and IN-2). The third point was located 400 feet east of the proposed mined-out area (point B). The points were set by starting at a known elevation approximately 6640 feet from the first north panel. Transit survey points were read about every 400 feet. A survey was again conducted on April 21, 1995 to record the elevation of the monitoring points. The survey techniques were the same as those used m the original May 26, 1988 survey but indicated that point B was higher by 1.26 inches, point [N 1 higher by 1.86 inches and point IN-2 lower by 1.032 inches. „n~ ` The subsidence monitoring section of the approved permit allows a "no change in elevation" ~`~\ `J4~r``'\. nding to be made when there is less than ± 0.25 feet (3.0 inches) elevation difference in W1 the survey. According to the permit this is the inherent survey error. Also, according to the T permit, "after five years with no change in the survey coordinates (± .25 feet), these surveys