Good practices of post mining land rehabilitation works in the southern region of East Kalimantan, Indonesia

Abstract

Open-pit/cut/cast mining is a method of extracting coal directly from the surface using a series of level benches to reach the deposit close to the surface overlain by relatively thin vegetation, topsoil, and rocks. During the year of 2010 - 2017 PT Kideco Jaya Agung (KJA) has rehabilitated post mining land 1.379,54 ha in area. The objective of this study was to examine practices of degraded land rehabilitation works and understand good practices of post mining land rehabilitation at minedout forest lands. A number of 750 plots (25mx40m) were established in 2022 to evaluate practices of land arrangement, soil erosion and sedimentation control, and land revegetation works. Rehabilitation activities that have been going well based on established plan were: waste dump arrangement, topsoil spreading, cover crops planting, plant growth rate, number of plant per-Ha, and plant health. However, rehabilitation works that still require improvement were slope stabilization, number and benefits of soil and water conservation infrastructures, excessive soil eronsion, and the composition of long life and fast growing plant species. The evaluation score of post mining rehabilitation works was 22,5 for land arrangement, 17,5 for soil erosion and sedimentation control, and 48 for land revegetation respectively with the total score 87,5. The total score indicates that forest rehabilitation works has been carried out properly based on good practices of coal mining principles.