Analisis kualitas air sungai dan tanah di areal reklamasi tambang batubara PT Berau Coal Site Binungan, Provinsi Kalimantan Timur

Abstract

Salah satu hal terpenting dalam aktivitas penambangan batubara dengan sistem tambang terbuka adalah bagaimana melakukan reklamasi lahan dan mengembalikan agar kelestarian lingkungan tetap terjaga. Reklamasi lahan pasca tambang merupakan bagian dari perencanaan dan pelaksanaan kegiatan penambangan untuk memastikan agar upaya perbaikan lahan-lahan yang terganggu oleh kegiatan pertambangan dapat dilaksanakan secara efektif dan efisien dengan mempertimbangkan karakteristik kondisi fisik, kimia, dan biologi tanah. Sampai saat ini reklamasi yang telah dilakukan diduga belum ada yang berpihak pada pembangunan kawasan pasca tambang batubara yang berkelanjutan dengan menganut prinsip memanfaatkan, melindungi dan melestarikan lingkungan. Sementara itu, pelaksanaan reklamasi yang dilakukan sampai saat ini sifatnya sekedar memenuhi tuntutan prosedur yaitu hanya menjadikan reklamasi sebagai bagian dari persyaratan pelaksanaan pertambangan batubara yang kebanyakan belum memadai. Kegiatan reklamasi ini selain ditunjukan untuk memperbaiki sifat-sifat tanah, diharapkan juga akan memperbaiki kualitas air permukaan di sekitar areal reklamasi. Oleh karena itu perlu dilakukan penelitian untuk mengetahui kondisi air dan tanah di sekitar areal daerah tersebut. Dengan penelitian ini, diharapkan menjadi acuan dalam pelaksanaan reklamasi yang berkelanjutan.

Coal mining activities without reclamation will lead to environmental degradation such as change of freshwater and soil qualities. Reclamation of post mining land is part of the planning and implementation of mining activities to ensure that repairing of lands affected by mining activities can be conducted effectively and efficiently by improving the post mined soil conditions. This research was aimed to analyze the qualities of river water around and soil in the mining area of PT Berau Coal Binungan Site. Samples of river water were taken as many as 10 locations, whereas soil samples were taken from soils of land after 0, 3, 6, and 9 years of reclamation and forest soil. The results showed that some of the parameters of water such as temperature, pH, DO, Fe, Mn, oils and fats, were below the grade I Quality Standard of Government Regulation No. 82/ 2001. However, COD was above Grade III, while BOD was above grade IV of the Quality Standard. These indicates that all the water sample were not qualified as standart drinking water (grade I). Results of soil analysis indicated that physical, chemical and biological of soil properties varied both due to the increase in reclamation age and the heterogeneous nature of the soil materials. Properties including BD, infiltration, aggregate stability, organic-C, and biological properties were improved with increasing the age of reclamation approaching the properties of forest soil. Other properties including pH, CEC, exchangeable bases, base saturation, available P, available micro elements, and total S were varied due also to the heterogeneous nature of the soil material.