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14 <br />addressed within the permit, and the bond release application, pursuant to Rule 3.03.1(3)(c). <br />Subsidence Impacts <br />Coal extraction within the Red Canyon Mine occurred between 1978 and 198. Extraction was limited <br />to 5~%, with 50% maximum extraction beneath structures, to prevent subsidence damage. Mine <br />workings were developed using four to seven entry systems, with width of the workings ranging from <br />approximately 200 to 500 feet. Residences which were in existence prior to undermining were <br />inventoried, and subsidence survey monuments were installed. Mining ceased in 1984. Monitoring of <br />inventoried structures and survey monuments was conducted between 1982 and 1986, with suspension <br />of monitoring approved 12/31/86. One additional subsidence monitoring report was submitted in 1989, <br />associated with a permit renewal. The Division approved cessation of subsidence monitoring with the <br />approval of Technical Revision No. 9, on June l ~, 1992. Division correspondence associated with the <br />revision noted that May, 1989, monitoring had detected a maximum of 0.3 feet of residual vertical <br />subsidence, and further noted that none of the protected and monitored structures had evidenced any <br />subsidence. The approval of the termination of subsidence monitoring included the provision that <br />monitoring would be reinitiated if any evidence of renewed subsidence were discovered. Page 155 of <br />the permit application, approved by TR-09, states: <br />There is no further requirement for subsidence surveys at the Red Canyon Mine unless <br />there is physical evidence or alleged physical evidence that subsidence has damaged the <br />surface within the area of influence of the mine or subsidence has damaged on of the <br />structures listed on Table 2.05.6(6)(a)(ii)(A)-I. <br />Prior to issuance of landowner notices regarding the bond release application, the Division had not <br />received any reports of apparent subsidence damage within the affected area. In response to the bond <br />release notification, two permit area landowners (Leslie Truitt and Jack Amey), and one adjacent <br />landowner (James Hudson), reported features on their property which they were concerned might have <br />been caused by Red Canyon Mine subsidence. Mr. Truitt and Mr. Hudson were concerned with possible <br />subsidence caused damage to residences on their property (cracks in concrete foundations, basement <br />floors, and drywall; door jambs uneven, etc.). Mr. Amey was concerned with a surface crack on an <br />undeveloped portion of his property. The houses on the Hudson and Truitt properties had been <br />constructed subsequent to the inventory conducted by the operator, and were therefore not documented <br />in the permit. There was a trailer house located on the Truitt property which also was not documented <br />in the permit. Mr. Truitt was uncertain how long the trailer had been in its current location. Based on <br />inspection of properties of concern, and review of permit documentation and monitoring records, the <br />Division has determined that the features were not the result of subsidence associated with the Red <br />Canyon Mine. <br />The operator had notified landowners whose property was over or immediately adjacent to undermined <br />areas, in a letter of August 19, 1993. The letter explained the location and extent of mine workings, and <br />noted that there was a "remote possibility that subsidence could occur" on their property. Our records <br />