Impact of Industrial Effluents on Dhaka Export Processing Zone's Water Bodies: A Comprehensive Analysis

The Bangladesh Export Processing Zones Authority (BEPZA) is actively addressing environmental concerns, notably water pollution, in the Dhaka Export Processing Zone (DEPZ). Despite the Central Effluent Treatment Plant’s (CETP) crucial role in mitigating industrial wastewater pollution, challenges persist, particularly in garment dyeing and washing. The design, building, and operation of the CETP have contributed to the enhancement of environmental rules. However, contamination from textile industries poses a significant threat to aquatic ecosystems and public health, necessitating immediate regulatory action. A recent study focused on wet industries in the Dhaka EPZ, employing flow measurement techniques like Chezy’s equation and rectangular thin plate weirs to assess wastewater emissions. Data revealed varying wastewater quality across industrial categories, with the textile and garment industries exhibiting significant impacts. Analysis indicated the need to double total suspended solids (TSS) levels and increase biological oxygen demand (BOD) and chemical oxygen demand (COD) amounts while adjusting fecal coliform levels for natural mortality. Daily flow patterns, peak factors, and discharge factors were also evaluated, emphasizing the importance of accurate data collection for informed decision-making in wastewater management. The study also examined daily expenses for businesses and discharge standards for sewers, inland waters, and irrigation, highlighting the financial and regulatory aspects of wastewater management. Factors such as discharge channels and pick factors influence wastewater quality in textile industries, prompting recommendations to enhance treatment efficiency. The BEPZA’s comprehensive assessment of wastewater quality underscores the importance of addressing parameters such as BOD, COD, TSS, and fecal coliform levels. Recommendations include modifications to improve water quality parameters, as well as the importance of precise flow measurement for equitable tariff structures and system design. Continuous monitoring and compliance are essential for safeguarding public health and environmental sustainability, with impacts extending to soil quality, crop productivity, and water resources.