VOID FILLING TIME SIMULATION AT PT XYZ

• Main Author: Kurniawan, Akbar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78459
• Institution: Institut Teknologi Bandung

One of the most visible impacts of mining activities is the existence of voids when open-pit mining activities end. The void that is formed will be left to be filled with rainwater, groundwater, and surface water. Based on the mine planning, the void of PT. XYZ can hold approximately 1.366.184.209 m³ of water at its spill point at an altitude of 260 msl. Void filing time simulation need to be carried out to determine the filling time so that management and environmental monitoring costs for postmining activities can be in accordance with the initial post-mining cost planning. The most important factors that influence the void filling time simulation are rainfall and the level of water evaporation that occurs in the future. In this study, monthly rainfall data was obtained from 5 rainfall stations in the PT XYZ mining area. Meanwhile, monthly evaporation data was obtained from secondary data in previous research. The monthly rainfall data and monthly water evaporation that have been obtained will be analyzed using the cumulative distribution function method and ARIMA forecasting method to determine the values of rainfall and evaporation that may occur in the future. In the cumulative distribution function method, there are 5 scenarios for void filling simulation which result in filling times between 23,1-73,1 years. Meanwhile, using the ARIMA forecasting method the result in filling time is 76.3 years.