Assessment of Ambient Water Quality Deterioration in Proximity to Municipal Solid Waste Dumpsites in Urban Areas of Chattogram, Bangladesh

Abstract

This study aims to assess the impact of waste dumping on groundwater quality within the Chattogram City Corporation area. Monitoring eight groundwater sampling points over four years, various physical and chemical parameters were analyzed, utilizing the APHA method. Parameters assessed include pH, temperature, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), salinity, biological oxygen demand (BOD), chemical oxygen demand (COD), Turbidity, Total Hardness, Ca-Hardness, Alkalinity, TSS, Chloride, Phosphate, Sulphate, Nitrite, Nitrate, Fluoride, Iron, Arsenic, Zinc, Copper, and Chromium. The findings were compared to the Department of Environment's (DoE) recommended values, as well as the Bangladesh standard and World Health Organization (WHO) values. During sample collection, deep tube wells near the dumping site points were prioritized. According to the investigation CNB, Ananda Bazar Halishahar and Arefin Nagar, deep pump water carries too many irons in their groundwater. Iron levels exceed both WHO and Bangladesh standards across all samples. Specifically, Arefin Nagar and Ananda Bazar Halishahar area sampling points S6, S7, and S8 surpass standards in TDS, Total Hardness, Turbidity, TSS, Chloride, and Iron. Water Quality Index (WQI) calculations suggest unsuitability for drinking purposes in all sampled water, with S5 and S8 demonstrating particularly high values, indicating their unsuitability for human consumption. Heavy Metal Pollution Index (HPI) calculations reveal a decrease at CNB sampling points S1 and S2, where waste dumping ceased in 2017. However, HPI values at other points show an increasing trend, indicating the leaching of heavy metals from solid waste into groundwater. S5 and S8 exhibit notably high HPI values (Average 464.99 and 319.59), suggesting an accumulation of heavy metals in the groundwater. Carcinogenic Risk Analysis of Arsenic highlights the failure of most sampled water to meet Carcinogenic Risk (CR) standards, signalling a potential cancer risk with prolonged use of this water.