O Open-pit mining activities generate not only the primary commodity but also residual materials such as overburden, surface runoff, and fine sludge resulting from sediment control processes. the sludge is commonly contained within a mudcell as part of the mine environmental management system. once its operational function has ended, the mudcell needs to be closed and prepared for reclamation to minimize safety risks and land instability. at disposal 3 roto north of pt kideco jaya agung, a mudcell covering an area of approximately 4.14 ha with an average sludge thickness of approximately 22 m is located within the reclamation area. this condition disrupts landform continuity and requires proper closure planning prior to reclamation and revegetation.the main challenge in closure planning is the characteristics of the mudcell sludge, which has a very high water content, is dominated by fine-grained silt-clay material, is in a saturated condition, and indicates low bearing capacity. these conditions make the material susceptible to settlement and instability if directly backfilled without appropriate technical treatment. in addition, the limited access road width of approximately 6 m is an important consideration in selecting suitable closure methods and equipment.this study aims to identify the physical characteristics of the sludge and the geotechnical conditions of the mudcell, analyze several closure methods, evaluate their technical and economic aspects, and determine the most feasible method for preparing the area for reclamation. a descriptive and comparative approach was applied, including field and laboratory data collection, analysis of existing conditions, estimation of sludge and water volumes, development of closure alternatives, technical evaluation, and analysis of implementation costs and duration.the results indicate an estimated sludge volume of approximately 747,452 m³ and a surface water volume of approximately 41,245 m³. the sludge is predominantly composed of silt-clay material, with a water content ranging from 90.8% to 106.5% and a slurry specific gravity ranging from 1,20 to 1,30. these characteristics indicate very soft and saturated material conditions; therefore, direct backfilling without technical treatment is not recommended. four closure methods were analyzed: a mechanical method involving full dewatering and sludge removal, in-situ consolidation and preloading, chemical stabilization and a capping system, and a combined method involving limited dewatering and in-situ soil improvement. each method was evaluated based on technical suitability, occupational safety risks, access limitations, implementation duration, and estimated costs.the evaluation results show that the mechanical method can comprehensively handle the sludge but requires the removal of a large volume of material, involves high costs, and presents greater operational risks. the in-situ consolidation and preloading method does not require large-scale sludge removal but requires a longer period for consolidation and monitoring. chemical stabilization and capping can improve the material in situ but require a large quantity of binding agents. the combined method provides a better balance by integrating limited dewatering, preloading, settlement monitoring, and localized soil improvement in areas requiring stabilization, thereby reducing the need for overall sludge removal and providing greater suitability for the limited site access.based on the technical and economic evaluation, the combined method is recommended as the most feasible mudcell closure method for disposal 3 roto north, with an estimated cost of approximately idr 10,2 billion and an implementation duration of approximately 4.75 months. this method provides an appropriate balance among technical feasibility, operational risks, implementation time, and cost, and is expected to provide more stable land conditions as preparation for reclamation and revegetation.