Coal mining in India: a study of environmental problems and effects on soil resources due to surface coal mining

Coal remains central to India's energy mix, yet the rapid expansion of surface (opencast) mining has imposed severe environmental costs, particularly on soil resources. This review synthesizes peer-reviewed studies and official reports to assess the physical, chemical, and ecological degradation of soils in India's coal mining regions, along with restoration strategies and policy frameworks. Findings reveal consistent patterns of topsoil loss, increased bulk density, reduced moisture retention, and significant depletion of soil organic carbon. Widespread contamination by potentially toxic elements such as Cr, Pb, Cd, Ni, and Cu, coupled with acid mine drainage, further degrades soil quality and mobilizes metals. At the landscape scale, multi-decadal land-use and land-cover changes across central Indian coalfields show marked declines in forests and water bodies, accompanied by growth of mining pits, overburden dumps, and transport corridors that fragment habitats and disrupt hydrology. A case study from the Raniganj Coalfield illustrates the severity of impacts, with soils exhibiting broad pH and EC variability and elevated trace-element concentrations above regional baselines. Evidence indicates that the construction of Technosols, integrated multi-tier revegetation with native grasses and trees, combined with phytoremediation, bioremediation, microbial inoculants, biochar amendments, and constructed wetlands, can substantially improve soil structure, enhance nutrient availability, stabilize toxic metals, and accelerate ecological recovery. Although policy instruments such as Environment Impact Assessment/Environment Management Plan requirements, mine-closure guidelines, and restoration norms exist, enforcement and ecological performance monitoring remain inconsistent. This synthesis proposes an integrated framework combining geospatial monitoring, soil-biota indicators, and community participation to restore soil functionality, biodiversity, and climate resilience in India's coal mining landscapes.