Surface Water Quality Assessment in the Different Coastal Regions of Bangladesh

The study evaluated the suitability of surface water for routine utilization in the coastal regions of Bangladesh during the period from February to May 2023. Water samples were collected at 11 sampling stations near the river in 7 distinct districts and analyzed at NGO Forun in Dhaka using Standard APHA methods. The results indicated that the pH, TSS, DO, nitrate, and BOD readings were within acceptable limits according to WHO’11 standards. The TDS, chloride, hardness, and EC values at all sites exceeded the allowable range. The TDS and EC values were 25,300 mg/L and 50,570 µs/cm at Kutubdia, while chloride and hardness were 5,984 mg/L and 9,810 mg/L at Bhatiary, which were the highest values among all stations. The minimum values recorded for TDS, chloride, hardness, and EC were 330 mg/L, below 60 mg/L, 90 mg/L, and 645 µs/cm, respectively. GIS was used to understand the scenario of acceptability of surface water in the coastal region. The correlation analysis revealed a high positive correlation between the EC value and the hardness, chloride, BOD, and TDS readings. Surface water EC values may increase due to saline intrusion caused by rising sea levels, decreased upstream flow, natural disasters, and increased groundwater exploitation.