Perencanaan Teknis Sump Baru Tambang Batu Bara di Pit North Wara PT Adaro Indonesia

Abstract

This research highlights the importance of planning a mine dewatering system as a solution to address water-related issues in PT Adaro Indonesia's pit North Wara, located in Tabalong Regency, South Kalimantan. Focusing on the increasing volume of slurry and soil erodibility, the design of a new sump involves hydrological analysis, sump capacity, sustainability, operational safety, and environmental studies in accordance with Kepmen 1827K/30/MEM/2018. The study comprises steps such as literature review, field observations, and data collection (both primary and secondary). The results reveal a planned 10-year return period rainfall of 126.950 mm with an intensity of 44.011 mm/hour. The total runoff is calculated to be 1,263,057 m3 /day, while the evapotranspiration rate is 96,274 m3 /day. Covering an area of 201.4 hectares, the estimated erosion rate is 997.25 m3 /day or 4,873 tons/day, leading to a total combined water and slurry discharge of 1,180,911.07 m3 /day. To manage the inflow issue at Pit North Wara, a trapezoid-shaped sump with a volume of 1,200,000 m3 , utilizing 3 Multiflo 420EXHV pumps, is proposed. The pumps can operate with an average actual use of 80%. Based on the calculation, the pumps can discharge 72,576 m3 /day.. From the erosion rate calculation using the MUSLE method, the estimated time to reach the full pond is 9.36 months. This research offers an efficient and sustainable solution to address water challenges at the mining location.