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<br />ANNUAL MINE INFLOW REPORT <br />1988 Page -3- <br />WATER IMPORTATION AND BALANCE <br />CWI mined approximately 327,400 tons of coal from July 1st, 1987, to July 1st, <br />1988. Estimated tonnages for the next 12 months are at approximately 350,000 <br />tons. Hence production should no[ change drastically. <br />Mine water importation is best estimated from recorded flows and related ton- <br />nages at the Orchard Valley Mine from September, 1985, through April, 1986. <br />Calculations from recorded measurements indicated approximately 2.SX by weight <br />of imported water (in relation to the total raw coal tonnage) is used for face <br />and roadway dust control. This relates to an import water usage of 1,970,000 <br />gallons from July, 1987, to July, 1988. <br />From detailed coal sampling at the face and on the surface, an approximate 1X <br />moisture gain from the inplace value to the [rain loadout point is apparent. <br />Consequently, 790,000 gallons of water is imported for face coal dust control. <br />Therefore an approximate 1,180,000 gallons of water is used for roadway dust <br />control along with a small percentage of this evaporating as humidity into the <br />air and being expelled from the mine. <br />HYDROLOGIC IMPACTS <br />No significant increase in mine inflow occurred relevant [o undermining both <br />East Roatcap Creek and Steven's Gulch drainage during development of various <br />Sub-Mains within the Orchard Valley West Mine. Approximately 280' of cover sep- <br />arated East Roatcap Creek from South III Sub-Main entry development. Virtually <br />no amount of inflow occurred while mining in this area and what small a<noun[ did <br />exist has completely dried up. <br />Small wet areas are still evident within the entries directly below Steven's <br />Gulch with an overburden depth slightly greater than 300 feet. This difference <br />is probably due ~to the greater depth of collwial material and hence shallower <br />bedrock within the Steven's Gulch drainage relevant [o the East Roatcap area. <br />Inflow amounts should not increase significantly within the next year as the ma- <br />jor concerns of mining under East Roatcap and Steven's Gulch have been accom- <br />plished with favorable results. Advancement of Panel G under and adjacent to <br />the Steven's Gulch buffer zone should allow minimal mine inflow. No pillar ex- <br />traction will occur within the buffer zone area, only developmental mining will <br />be done. <br />Within the next year, little more than short-term natural inflows should occur <br />in the new mined out areas. Any increase in natural inflow will be approximate- <br />ly proportional to the increase in developed area. <br />CONCLUSIONS <br />Present mine inflow into the Orchard Valley Wes[ Mine is low. The present flow <br />rate is slightly below 1,570,000 gallons annually. <br />We[ areas within the Orchard Valley West Mine are more numerous in proportion to <br />mined out areas than the Orchard valley Mine but the OVWM still remains a rela- <br />tively dry mine. <br />