Electronic Theses and Dissertation

PT Indonesia Pacific Energy merupakan perusahaan tambang batubara terbuka di Kabupaten Aceh Barat yang menggunakan temporary sump dengan dimensi mengikuti kemajuan penambangan tanpa didasarkan pada analisis hidrologi serta pompa rakitan tanpa kurva karakteristik pabrikan, sehingga temporary sump mengalami overflow saat hujan berintensitas tinggi dan mengganggu aktivitas coal getting. Penelitian ini bertujuan mengevaluasi kecukupan kapasitas temporary sump, kinerja sistem pemompaan, saluran terbuka, dan settling pond eksisting terhadap debit air masuk pada kondisi hujan rancangan periode ulang 2 tahun serta menyusun rekomendasi teknis sistem dewatering. Curah hujan rancangan dianalisis menggunakan distribusi Log Pearson III, debit aktual pompa diukur dengan metode discharge, dan kecukupan sistem dievaluasi melalui analisis water balance. Hasil penelitian menunjukkan total debit air masuk sebesar 4.844,40 m³/jam atau 37.021,13 m³/hari. Kapasitas temporary sump eksisting sebesar 10.433,82 m³ belum mampu menampung volume air masuk sebesar 36.333,07 m³, sedangkan kapasitas pemompaan eksisting sebesar 4.042,35 m³/hari belum mampu memenuhi kebutuhan pemompaan sebesar 37.021,13 m³/hari. Saluran terbuka eksisting berkapasitas 0,183 m³/detik masih memadai terhadap debit pompa eksisting sebesar 0,0695 m³/detik, namun settling pond eksisting berkapasitas 724,90 m³ belum mampu menampung 1.877,25 m³ air hasil pemompaan. Direkomendasikan peningkatan kapasitas temporary sump menjadi 45.941,34 m³, penggunaan tiga unit pompa Sykes CP220i, perancangan ulang saluran terbuka berkapasitas 0,4674 m³/detik, serta peningkatan kapasitas settling pond menjadi 15.876 m³. Rekomendasi tersebut menghasilkan sistem dewatering yang mampu mengendalikan debit air masuk secara efektif pada kondisi hujan rancangan periode ulang 2 tahun.

Kata Kunci: Sistem Dewatering Tambang, Temporary Sump, Kinerja Pompa, Water Balance, Curah Hujan Rancangan

PT Indonesia Pacific Energy is an open-pit coal mining company located in West Aceh Regency that utilizes a temporary sump whose dimensions are determined based on mining progress rather than hydrological analysis, along with locally assembled pumps lacking manufacturer performance curves. Consequently, the temporary sump frequently experiences overflow during high-intensity rainfall, disrupting coal getting operations. This study aimed to evaluate the adequacy of the existing temporary sump capacity, pumping system performance, open channel, and settling pond in handling mine water inflow under a 2-year return period design rainfall and to propose appropriate technical recommendations for the mine dewatering system. Design rainfall was determined using the Log Pearson Type III distribution, the actual pump discharge was measured using the discharge method, and system adequacy was evaluated through a water balance analysis. The results showed that the total mine water inflow reached 4,844.40 m³/h or 37,021.13 m³/day. The existing temporary sump, with a capacity of 10,433.82 m³, was unable to accommodate the inflow volume of 36,333.07 m³, while the existing pumping capacity of 4,042.35 m³/day was insufficient to meet the required pumping capacity of 37,021.13 m³/day. The existing open channel, with a capacity of 0.183 m³/s, was adequate to convey the actual pump discharge of 0.0695 m³/s; however, the existing settling pond, with a capacity of 724.90 m³, was unable to accommodate 1,877.25 m³ of pumped water. The recommended improvements include increasing the temporary sump capacity to 45,941.34 m³, utilizing three Sykes CP220i pumps, redesigning the open channel with a capacity of 0.4674 m³/s, and increasing the settling pond capacity to 15,876 m³. These recommendations enable the mine dewatering system to effectively manage mine water inflow under the 2-year return period design rainfall. Keywords: Mine Dewatering System, Temporary Sump, Pump Performance, Water Balance, Design Rainfall