Electronic Theses and Dissertation

Pengelolaan air tambang merupakan aspek penting dalam kegiatan pertambangan karena berhubungan langsung dengan upaya pencegahan pencemaran lingkungan dan pemenuhan standar baku mutu air. Salah satu fasilitas utama yang digunakan adalah settling pond, yaitu kolam pengendapan yang dirancang untuk menurunkan kadar sedimen tersuspensi sebelum air dibuang ke badan penerima. Sesuai ketentuan KEPMEN ESDM Nomor 1827 K/30/MEM/2018, settling pond diwajibkan memiliki kapasitas minimum sebesar 1,25 kali volume air tambang pada kondisi curah hujan tertinggi selama periode 84 jam. Penelitian ini bertujuan untuk menganalisis desain dan kinerja settling pond yang berada di Pit 4 PT Bara Energi Lestari, menilai kesesuaiannya terhadap ketentuan teknis yang berlaku, serta mengevaluasi efektivitas pengendapan sedimen pada setiap unit settling pond. Metode penelitian melibatkan pengumpulan data curah hujan maksimum tahunan periode 2014–2023 menggunakan Automatic Weather Station (AWS) dan ombrometer sebagai instrumen pembanding untuk meningkatkan akurasi data. Data dianalisis dengan distribusi Log Pearson Tipe III untuk memperoleh curah hujan rencana pada periode ulang 2 dan 5 tahun. Intensitas hujan dihitung menggunakan persamaan Mononobe, kemudian debit limpasan ditentukan melalui persamaan rasional berdasarkan luas catchment area. Selanjutnya, kapasitas aktual masing-masing settling pond dibandingkan dengan kapasitas rencana sesuai standar, serta ditinjau dari segi persentase efisiensi pengendapan. Hasil analisis menunjukkan bahwa hanya Settling Pond 06 yang memenuhi standar kapasitas minimal dengan waktu retensi lebih dari tiga hari (84 jam), sedangkan Settling Pond 04, 05, dan 07 memiliki waktu retensi antara 12 hingga 18 jam sehingga belum memenuhi standar. Rata-rata efisiensi pengendapan mencapai 94%, menandakan kinerja pengendapan tergolong baik meskipun kapasitas sebagian kolam masih perlu ditingkatkan. Oleh karena itu, disarankan adanya optimasi desain dan peningkatan kapasitas tampung agar sistem settling pond dapat berfungsi lebih efektif dalam mengendalikan kualitas air tambang.

Mine water management is an important aspect in mining activities because it is directly related to efforts to prevent environmental pollution and meet water quality standards. One of the main facilities used is a settling pond, which is a sedimentation pond designed to reduce the level of suspended sediment before the water is discharged into the receiving body. According to the provisions of the Minister of Energy and Mineral Resources Decree Number 1827 K / 30 / MEM / 2018, settling ponds are required to have a minimum capacity of 1.25 times the volume of mine water at the highest rainfall conditions during an 84-hour period. This study aims to analyze the design and performance of settling ponds located in Pit 4 of PT Bara Energi Lestari, assess their compliance with applicable technical provisions, and evaluate the effectiveness of sediment deposition in each settling pond unit. The research method involves collecting annual maximum rainfall data for the period 2014–2023 using an Automatic Weather Station (AWS) and an ombrometer as a comparison instrument to improve data accuracy. Data were analyzed using a Log Pearson Type III distribution to obtain the planned rainfall for return periods of 2 and 5 years. Rainfall intensity was calculated using the Mononobe equation, then runoff discharge was determined using a rational equation based on the catchment area. Next, the actual capacity of each settling pond was compared with the standard design capacity, and reviewed in terms of the percentage of settling efficiency. The analysis results showed that only Settling Pond 06 met the minimum capacity standard with a retention time of more than three days (84 hours), while Settling Ponds 04, 05, and 07 had retention times between 12 and 18 hours and therefore did not meet the standard. The average settling efficiency reached 94%, indicating that the settling performance was relatively good, although the capacity of some ponds still needs to be improved. Therefore, it is recommended to optimize the design and increase the storage capacity so that the settling pond system can function more effectively in controlling mine water quality.