Seasonal Variation of physico-chemical and microbiological properties in different banks of Ganga (Hooghly) River in West Bengal

Pre-monsoon (April -June), monsoon (July -September) and post-monsoon (October-December) seasonal variations of coliform bacteria, along with some physico-chemical properties like pH, temperature, DO and BOD of different banks of Hooghly River (Ganga) in the district North 24 Parganas, West Bengal were studied for three years (2022)(2023)(2024).Data analysis showed that different banks of the river were mostly affected by fecal coliforms in 10 5 -10 6 range.Dakhineswar bank of the Ganga River was found to be most contaminated with fecal coliforms, followed by Baro mandir river bank of Sodepur and Nababgunj river bank of North Barackpore in monsoon season.The plate count exhibited average 10 2 fold higher coliform in every monsoon in comparison to other seasons.The average DO and BOD levels in all the river banks exceeded the BIS standard of 5 mg/L and 3 mg/L respectively.Highest concentration of multiple heavy metal resistant coliform was found in the Dakhineswar river bank (MIC 750 g/mL for Pb, 250 g/mL for Zn, 100 g/mL for Cd and 500 g/mL for Cr respectively), followed by Sodepur baro mandir river bank (MIC 250 g/mL for Pb, 100 g/mL for Zn, 100 g/mL for Cd and 500 g/mL for Cr respectively).