ASSESSMENT OF WATER QUALITY PARAMETERS OF AN ABANDONED OPENCAST COAL PIT (OCP) OF ASANSOL-RANIGANJ COALFIELD (ARCF), PASCHIM BARDHAMAN, WEST BENGAL, INDIA

Abstract

Coal mining and its auxiliary actions have already been proved to cause potential pollutions to ecosystems. This research work assesses the surface water quality of Samdihi abandoned Opencast Coal Pit (OCP) of Asansol-Raniganj Coalfield Areas (ARCF). Twenty seven water samples were collected maintaining temporal variability and were analyzed for physicochemical attributes.  The pH was slightly alkaline with lowest of 7.8 during winter. The water temperature varied between 20 and 35°C. Conductivity was highest during winter (601±3.51 µS/cm) and lowest during monsoon (333±2.8 µS/cm). The Total Suspended Solids (TSS) and Total Dissolved Solids (TDS) ranged from 212 to 2738 mg/L and 170 to 413 mg/L respectively. The low values of TSS (212 mg/L) and TDS (170 mg/L) were observed during winter and the higher values of TSS (2738 mg/L) and TDS (413 mg/L) were observed during monsoon. The dissolved oxygen concentration was moderately high (between 6.89 and 8.43 mg/L) but comparatively higher (8.5 mg/L) in monsoon. The estimated dissolved concentration of phosphate, sulphate, sodium and potassium were 4.2±0.17, 98.6±10.48, 8.6±0.47 and 2.5±0.75 mg/L respectively. Zooplankton population in the OCP was found to be 8±1.76 ind/mL in monsoon and 14±1.12 ind/mL in winter with an impressive abundance of 157/L and 274/L in monsoon and winter respectively. The water chemistry suggests the non-potability compared to prescribed standards but the chemical attributes showed promising traits for pisciculture, aquaculture, horticulture and/or other recreational practices that may assist in improving the socio-economic condition of the community habituating in and around the area.