Analisis Sistem Penyaliran Tambang pada Sump Pit Taman Penambangan Air Laya PT. Bukit Asam (Persero), tbk. Unit Penambangan Tanjung Enim Sumatera Selatan

PT. Bukit Asam (Persero), Tbk. mining unit of Tanjung Enim has done mining activity with surface mining system, which use open pit mining method so it makes a cavity. The big problem based on open pit mining method is rainwater and groudwater. In PT. Bukit Asam (Persero), Tbk, while rainwater upcoming, it causes sump flooded. In under sump, there is coal area, so needs water level control before one day the coal is mined and debit water is not worrisome. Based on the analysis of rainfall data in 2007 until 2016, rainfall was obtained by 135,6 mm / day, rainfall intensity 54,366 mm / hour with 10 year rainfall period. At the location of the study obtained the area of catchment area of 216,900 m2, total discharge into the sump of 9268,5 m3 / day. Using 2 multiflo pumps where pump 2 is auxiliary pump to support pump performance 1 during the rainy season. The capacity of both pumps is 6696 m3 / day and with the use of working hours is 3 hours per day. With 3 hours of work for one day on each pump is not able to pump water, it is necessary to add hours to support water pumping. For the sake of more efficient results then the reduction of the number of pumps to use only 1 pump with working hours for 8,4 hours or 8 hours 24 minutes for one day.