The global concern about water quality in coal mining operations is a significant issue. It presents detrimental water-related threats, including pollution, acid mine drainage, and habitat destruction. In this study, an attempt has been made to evaluate the water quality for domestic, irrigation and industrial purposes in the coal mining province of Mahan catchment area, with a particular focus on the impact of coal mining activities. 50 samples from pre-monsoon season of 2018, collected from dug well, tube well, mine water and river water were analyzed. The findings indicate that water in the study area exhibits acidic characteristics, with pH values below the desirable range for drinking water. Elevated electrical conductivity, total dissolved solids, sulphate, total hardness and chloride concentrations are observed, particularly around core mining regions. For irrigation suitability, the study reveals that most of the samples are suitable, based on parameters such as sodium percent-age (Na%) sodium adsorption ratio (SAR), magnesium hazard (MH), Kelly's index (KI), permea-bility index (PI), and residual sodium carbonate (RSC). However, majority of the samples collected from core mines show an elevated range of Na% (>80), SAR (>60), MH (>50), KI (>1), PI (>100), RSC (>2.5) and PS (>5) indicating potential soil permeability issues and crop damage, which restrict its suitability for agricultural use. Furthermore, the assessment of water for industrial suitability by analyzing the scaling and corrosion indices, such as the Langelier index (LI), aggressive index (AI), Ryznar index (RI), Puckorius index (PI), and corrosivity ratio (CR) highlights the presence of a corrosive tendency in majority of the water samples, particularly in the mining areas.

The current study compares black carbon radiative effects at the densely populated plain station, Varanasi and the lesser populated plateau station Ranchi with large forest cover but with numerous open coal mines. While the measured average black carbon mass density (BC) reduces from February to March at Ranchi following an increase in convective mixing, it is observed to increase by 150% from February to March in Varanasi, as transport from northeast forest fires increases. It is observed that absorption due to black carbon of non-fossil fuel origin is prevalent throughout the day, in Varanasi, while this contribution is most significant during post sunset hours in Ranchi. Radiative forcing, estimated hourly using chemical model (to derive BC-aod) and radiative transfer model, indicates that at least 5% of the incoming radiation is always cutoff during any time of the day in Varanasi while this is about 4% in Ranchi. BC effectively causes an apparent delayed sunrise by reducing the incoming radiation on the plains of Indo Gangetic Basin (IGB) by up to 25% at the daybreak. An estimate of crop loss due to cut off in radiation, using an empirical formula for crop yield as a function of radiation, indicates a possible loss of more than a quintal per hectare considering anthesis (February) and maturity (March) periods for the winter wheat in both the IGB stations with consistently higher losses in Varanasi.