1 Chapter I Introduction I.1 Background The coal commodity is still one of the important natural resources used in various industrial sectors. Coal is still one of the important natural resources used in multiple industrial sectors. Based on the projection results, the BaU scenario primary energy mix in 2025 for renewable energy is 21%, gas 24%, coal 34%, and oil 21%, and in 2050 the share of renewable energy rises to 29%, gas 23%, coal 32%, and oil 16%. (Sekretariat Jenderal Dewan Energi Nasional, 2019). PT BIB is a coal mining company that conducts mining activities through open- pit mining. The open-pit mining method has a large environmental impact. This method, which involves excavating soil and rock at the surface to extract minerals, often creates a range of serious environmental problems. Large-scale land clearing and excavation can cause soil degradation and increase the risk of sedimentation erosion. Exposed soil can be easily washed away by water and cause sedimentation in rivers or other surface waters. In 2024, PT BIB has a coal production target of 46.8 million tonnes with a land clearing plan of 1,383 hectares. This target will continue to increase by 54 million tonnes with a total cumulative land clearing plan of 10,465 Ha. To anticipate wastewater and sediment due to mining activities and the vast land clearing, the company has several environmental management and monitoring mitigation measures based on the AMDAL environmental document, one of which is environmental management by making a sediment pond. A sediment pond is a pond made to accommodate and settle runoff water particles originating from mining sites or temporary material stockpiles before the water is discharged into the river body. The function of the settling pond is to settle mud or solid material from mine water before it flows into public waters and as a place to control water quality before it flows out of the settling pond. Currently, the number of sediment ponds is 29 units, and based on the 54 2 Million tonnes BIB Feasibility study document the cumulative number of sediments until 2036 is 58 units. To keep the sediment pond functioning optimally, it is necessary to carry out periodic maintenance to normalise the sedimentation sludge in the sediment pond. Sediment pond normalisation is the maintenance of the storage pond and draining of the settling pond (Kepmen ESDM 1827 K/30/MEM, 2018). The sludge normalisation method currently used is the conventional method, using trucks and loading units to retrieve the sludge sedimentation in the sediment pond and then the sludge is discharged to the waste dump area. The current conventional method is less effective because there are often delays due to operational constraints such as the need for relatively many truck units, limited sources of material for blending, long mud disposal distances, the number of loading and truck units is not suitable if the unit is damaged so that productivity becomes low, normalisation activities cannot run if it is raining, and limited waste dump areas for mud materials. Some of these operational constraints, can cause potential environmental pollution and disrupt coal mining operations in the pit due to the inability to pump mine wastewater to the sediment pond.