PT SENAMAS ENERGINDO MINERAL GEOTECHNICS, HYDROLOGICAL AND HYDROGEOLOGICAL STUDIES

PT Geo Labora Indonesia successfully executed a comprehensivepast project a Geotechnical, Hydrology, and Hydrogeology Study for the open-pit coal mining operations of PT Senamas Energindo Mineral (PT SEM) located in Barito Timur, Central Kalimantan. The project was carried out as part of the company’s commitment to Good Mining Practice and in compliance with Ministerial Decree of ESDM No. 1827/2018,
ensuring safe operations, environmental responsibility, and long-term mining sustainability.

The work scope involved multidisciplinary technical activities that integrated field investigation, laboratory testing, numerical modeling, and engineering analysis. The project commenced with extensive fieldwork, including surface and subsurface geotechnical mapping, geotechnical drilling and core logging, hydrological measurements, installation of groundwater monitoring wells, slug tests, and in-situ water quality assessment. All field results were supported by certified laboratory testing for rock, soil, and water samples to ensure data accuracy and reliability.

During the analytical phase, PT Geo Labora Indonesia expert team performed deterministic and probabilistic slope stability simulations to evaluate slope safety under both static and dynamic (seismic) loading conditions. Concurrently, hydrology and hydrogeology assessments were carried out to quantify runoff discharge, infiltration capacity, and groundwater inflow into active mining pits, which made it possible to accurately estimate the total water inflow throughout the mining cycle.

The final deliverables of the study consisted of engineering recommendations crucial for safe and efficient mine development, including:

• Design of stable mining and disposal slope geometries,
• Mine dewatering system planning, including sump and open-channel dimensions,
• Settling pond engineering design to ensure compliance with environmental quality standards,
• Pumping system calculations, including required total pump capacity for each mine block.

The successful completion of this project further reinforces PT Geo Labora Indonesia’s capability in providing integrated geotechnical and water management engineering services for the mining sector. The outcomes of the study serve as a reliable technical foundation for PT SEM to operate safely, efficiently, and sustainably while mitigating geotechnical hazards and managing mining water effectively throughout the life-of-mine.