EVALUASI SISTEM PENYALIRAN TAMBANG BATUBARA PIT C EAT JOBSITE BINUNGAN SUARAN

Abstract

The mining area of PT. Berau Coal in Block 7 Binungan Suaran uses the open pit mining method with the contractor PT. Bukit Makmur Mandiri Utama. The application of this method causes the formation of giant basins that have the potential to become a place for water collection, both from rainwater, runoff. and groundwater. In-pit c east there are two sumps, namely sumps F2 at an elevation of -148 masl and sump O transfer at a height of -59 masl. Right under the sump, there is a coal seam that has not been extracted, economically the seam is feasible to mine, so it is planned to drain the sump and expand the sump to accommodate the incoming water. And it is necessary to repair the open channel so that the water flows well and the soil layer in the channel is not quickly eroded due to water discharge. Based on the data obtained and the results of calculations that have been carried out, the area of the rain catchment area in Pit C is 1.125,14 Ha.. The surface runoff water discharge in the area is 352.693,52 m3/day, groundwater discharge is 24 m3/day, the water seeps into the ground is 8.572,31 m3/day, and evaporation is 50.418,17 m3/day. From the groundwater budget, the total volume of water entering the rain catchment area is 293.727,05 m3/day. And the water discharge value in the open channel is 4,09 m3/second with a water flow velocity of 1,63 m/second