Laserfiche WebLink
Aspect <br />Mining Operation <br />Disturbed <br />Area <br />(acres) <br />A <br />Regrading side slopes for added stability; assume 20% of <br />slopes regraded to 3H:1 V — 2,000 feet x 79 feet <br />3.6 <br />B <br />Slurry Wall construction; 8,800 feet x 50 feet x 20 feet <br />10.1 <br />C <br />Miscellaneous disturbed areas <br />2.0 <br />Total Disturbed Area <br />15.7 <br />Mine Phasing <br />Due to the nature of the proposed activities, operations will not be subdivided into phases or <br />have distinctive directions of transition. <br />It is anticipated that reclaiming the proposed permit area will take approximately two to three <br />years. The rate of reclamation and overall life of the operation is dependent on several factors <br />including economic conditions. <br />Mining Methods <br />No significant mining methods are anticipated for the proposed reclamation operation. Earth <br />moving equipment on the site may include, but are not limited to dozers, loaders, and excavators. <br />Watering trucks may also be used for dust control and an employee /storage trailer, <br />fueling /lubricating station, and generators may be located on -site as needed. No bulk hazardous <br />materials will be stored on -site. <br />No mining highwalls will be created. No diversions or impoundments are expected to be used. <br />Material stockpiles will be temporary and left in place for less than one year. Side slopes of the <br />existing pit lakes have been graded to a 311:1V slope, but additional sloping may be necessary. <br />Material stockpiles associated with the Lafarge West Home Office Mine (M- 1977 -39) operations <br />are located in the far eastern permit area. Once the proposed eastern permit boundary is marked <br />on the ground, stockpile material within the proposed permit area will be removed to the existing <br />Home Office Mine permit area. <br />In order to gain an understanding of the extent of the existing mined area and reclamation <br />disturbances, it is helpful to know the acres disturbed by different aspects of the operation. Each <br />aspect is listed in the following table with associated disturbed area. The table illustrates the <br />current conditions, which represents the maximum mining disturbance since the final land use <br />includes water storage and a slurry wall or other form of liner needs to be constructed. For <br />disturbed area estimates, it is assumed that the existing excavation depth (bottom of lake to top <br />of adjacent land surface) is 25 feet. Although backfilling for reclamation has been completed, <br />construction of the slurry wall has not begun. <br />Treiber Lakes <br />DRMS 112 Permit Application <br />Page 6 <br />