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SOOTHWIsST MINING DISTRICT <br />• The impacts associated with mining the coal from this district are the same as predicted above. In addition to the <br />Wadge Overburden and Twentymile Sandstone, the Fish Creek Sandstone exists over portions of the southwest <br />+11)tining district. The Fish Creek Sandstone is localized in [his immediate area, and is approximately 950 - 1000 <br />(eet above the coal seam. <br />is not predicting any major impacts to the Fish Creek Sandstone. However, there may be short term <br />ory impacts due [o subsiding the area. This could result in lowering [he Fish Creek sandstone so that the <br />would issue from a new point. This point may be a lower elevation than the original point or from a <br />red zone, if present, within the area. <br />'hose impacts should not injure any party, and if injury does occur TCC does have the ability to augment any <br />eater loss from the unit. TCC will monitor the Fish Creek Sandstone unit during the mining episode [o determine <br />mpacts, if any. The monitoring program is contained in Exhibit 14. <br />~C does not anticipate any impacts [o [he Twentymile Sandstone unit resulting from its mining in the southwest <br />ine district. The moniroring to date does not show any negative impacts to this unit. Likewise, [here are no <br />rings on the mine property issuing from the Twentymile Sandstone, which eliminates the potential to modify the <br />~w regime of a spring. <br />iven the distance, and the depth of overburden, to both Fish and Foidel Creeks no impacts are anticipated to the <br />irface water system. Please refer to the above discussion concerning surface water impacts resulting from the <br />Fidel Creek Mine. <br />Historically, TCC utilized a 25° draw angle to determine distance required from panels to structure in order to <br />prevent subsidence impacts to them. TCC, through its extensive subsidence monitoring work, has collected data <br />which indicates the draw angle varies from 16° to 26°. However, behveen 16` and 26°, subsidence is minimal and <br />no significant surface impacts can be ascertained and it is TCC's opinion that a 16° draw angle is a more useful <br />planning constrain[. Therefore, TCC will utilize a 16° draw angle to determine distance from panel rib line to <br />structure for providing adequate protection of same. The calculations supporting [his angle of draw are presented <br />in Exhibit 7D, Revised Subsidence Predictions for Permit Revision No. 2. <br />oZ • ~ • 3 (4) Ponds, Impoundments and Diversions <br /> <br /> fa) General. A eeneral plan and detailed desien plan For each sediment Hood, water <br />impoundment and diversion proposed to be constructed within [he permit area. <br />(i) Each e,eneral plan shall: <br />(A) Be prepared bv, or under the direction of, and certified by a qualified <br />reeistered professional en¢ineer, or by a professional eeoloeist with assistance from exuerts in related fields such <br />as surveyine and landscape architecture; <br />(B) Contain a description, map, prepared accordine to 2.10. and cross section <br />of the structure and its location; <br />. (C) Contain ureliminarV hvdroloeic and eeoloeic information required to <br />access [he hvdroloeic impact of the structure; <br />MR 97-I i4 2.0~-75 Rcvised 9/9197 <br />