2011-01-13_REVISION - C1981038 (8)

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within the permit area. In each case, a preferred repair methodology has been presented within the Subsidence Repair Handbook portion of the permit application (Volume 3). Calculations had been included to demonstrate that adequate water storage exists in the Pitkin Mesa Pipeline water distribution system to assure adequate water supplies in the event of a subsidence-related disruption to the pipeline. The company did not propose to mine pillars beneath the Pitkin Mesa Pipeline during the five-year permit term. Only development mining of main entries would occur under the pipeline and the Steven's Gulch Road within the Steven's Gulch buffer zone and no subsidence is projected. BRL submitted a pipeline repair plan, signed by Pitkin Mesa Pipeline Company as a condition of the approval of TR-19. Technical Revision No. 22, modified the coal lease and permit boundary to the west. The revised permit boundary included areas in the Long Draw Drainage. Upper Cabin Spring, water supply for Stucker Mesa Domestic Water Company, is located in the upper reaches of this draw. BRL submitted, to the Division, a signed copy of a water replacement plan agreement between BRL and Stucker Mesa Domestic Water Company (see permit application, Volume IA, Section 2.05.6, pages 98A to D. Subsidence Monitorine Prop-ram - BRL maintains a subsidence monitoring program for the Bowie No. 1 Mine. Originally, the program consisted of four components; visual inspection, wide-spaced grid subsidence monuments, closely spaced, high-resolution subsidence monuments and the monitoring of specific buildings and structures. However, with the suspension of mining operations in December of 1997, the subsidence monitoring program has been reduced in size and scope. The visual inspection phase is still in effect and consists of a walk-over of the ground surface above mined areas on a semi-annual frequency. In future permit periods, when renewable resource lands and structures may be undermined, pre- and post-mining inspections of structures will be incorporated. The applicant also commits to daily inspection of the Steven's Gulch road, in order to protect the public. BRL received approval to suspend the wide-spaced grid subsidence monitoring program. Monitoring stations No. 1 through No. 27 had comprised a wide-spaced monument grid on approximately 1300-foot centers east-west and 2600-foot centers north-south. These monuments provided general observations regarding the magnitude of vertical subsidence occurrences. Although not required, monument stations 6, 14 and 15 continue to be monitored twice a year and the results submitted to the Division in the Annual Report. Additional wide-spaced monuments No. 70 through No. 87 had been installed above proposed mine workings adjoining the old east portals. Monuments with the notations of some of the DH 50 series, DH-60 series and the 90 series had been installed above the underground workings at the West Mine. Several of the 90 series sites, 94, 96, 97 and 98, had been located on structures owned by the Grosse-Rhode Ranch. The high-resolution subsidence monitoring program has been suspended. A number of high-resolution, closely spaced subsidence monuments had been installed in sites selected throughout the existing permit area. Monitoring stations No. 201 through No. 224 had been installed above projected fault traces in an attempt to discern the effects of differential subsidence between alternating fault blocks. Stations No. 42 through No. 51 had been located in areas of thick overburden. Stations No. 28 through 41, in contrast, had been installed above overburden thicknesses considered typical throughout the permit area. The high-resolution subsidence data had been used to evaluate and further define the projected angle of draw. Data 40