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Borehole Pumn Substation <br />• TCC plans to install the Borehole Pump Substation southwest of the PM Bay. It will consist of four poles, a <br />transformer, and switchgear. The 50' x 50' area will be graveled and fenced with aten-foot high chain link fence. <br />The substation will tie into the overlying 69,000 volt line. Bonding calculations addressing removal of the Borehole <br />Pump Substation are presented in Appendix A, Volume IA. <br />69 ICV Powerline <br />TCC will construct a 69 KV powerline as shown on Map 24, Surface Facilities. The line will provide power to the <br />substation that powers the 8050 dragline. A trailing cable will extend from the substation located near the batch <br />weigh system to the dragline. Once the dragline, which is not the property of Twentymile Coal, is moved from the <br />site, the trailing cable will be removed from the site. It is anticipated the substation will be removed unless needed <br />for other applications at the mine. When the powerline is no longer needed, it will be taken down and removed <br />from the site. <br />Geotechnical Investieation -Batch Weieh System (MI295-114) <br />Twentymile Coal Company will conduct a geotechnical investigation of the proposed construction site for a batch <br />weigh train loading system and associated facilities. Detailed designs and a technical revision application for <br />construction of the batch weigh system will be submitted separately from the minor revision application addressing <br />the geotechnical investigation work for the project. The geotechnical investigation for these facilities will entail <br />drilling fourteen (14) shallow holes. The proposed drilling site locations are shown on Figure 20 in Volume 4 of <br />Permit C-82-056. <br />• Drilling will be conducted with aself-leveling track-mounted portable drilling rig (CME 45 mounted on <br />Bombazdier Snow Cat). Four inch (4")diameter continuous flight power augers will be utilized. Drill holes will be <br />driven to bedrock with core samples obtained as necessary to evaluate construction requirements for the proposed <br />facilities. Bedrock is known to occur at depths ranging from twenty (20) to sixty (60) feet in the vicinity of this <br />project. No drilling fluids will be utilized in association with the rig and no structures or preliminary site <br />preparation work will be necessary to support the drilling effort. <br />Thirteen (l3) proposed drill sites are located on previously disturbed areas and one (1) site is located in an area of <br />undisturbed native topsoil. Drilling is estimated to take approximately three (3) to six (6) hours per hole depending <br />upon the depth to bedrock. No topsoil salvaging operations are proposed in association with the drilling program as <br />drilling will likely occur under frozen ground conditions during the month of February 1995 and no significant <br />adverse impacts to the topsoil resource are anticipated. All drill sites are located in areas to be further disturbed during <br />construction of the batch weigh system facilities. Topsoil will be salvaged as appropriate during the initial <br />construction phase of the batch weigh system project. <br />The track mounted equipment utilized for the geotechnical investigation will produce minimal disturbance in <br />traveling over frozen ground and drilling for short duration's. Particular care will be taken to access the site with <br />undisturbed native soils during a period when frozen ground conditions are prevalent. To the extent possible, <br />cuttings generated during the drilling process will be returned to the drill holes prior to abandonment to minimize <br />potential sediment transport from each site. In the event an aquifer is intercepted during drilling at any site, the <br />affected drill hole will be sealed using a grout plug in the aquifer zone and then will be backfilled to the surface <br />with cuttings. In the event formation water is encountered during drilling and liberated on the surface, silt fences <br />will be erected as secondary sediment control measures to minimize the transport of sediment off site. <br />• Construction of the batch weigh system and associated facilities is anticipated to commence during March 1995. In <br />the event construction initiates on schedule, permanent sediment control measures and topsoil salvage <br />~s-~~'~?~yLPJ APR 2 4 2000 <br />Permit Renewal No. 3 2.05-48 I l/1/99 <br />