Environmental Assessment of Household Greywater in Chattogram City, Bangladesh: A Scoping Study

Untreated greywater that negatively impacts our environment is directly discharged even though it has the potential to be treated. Unlike traditional wastewater which requires a large-scale centralized treatment plants with huge infrastructural costs, greywater can be treated in a small-scale manner for use in irrigation. Hence, this chapter examines the primary quality of greywater present in Chattogram city by conducting an environmental assessment. 10 greywater samples were collected for chemical analysis and 5 for microbial examination from 5 different locations in Chattogram City. Water parameters like pH, Total Dissolved solids (TDS), Electrical conductivity (EC), Total hardness, Dissolved Oxygen (DO), Oxidation–Reduction potential, and other chemical analysis such as fluoride, chloride, phosphates, Sulphate, and nitrate levels were tested. Total coliforms and fecal coliforms were also evaluated through MPN tests and again cultured on EMB agar. Water parameters like Total hardness, Fluoride, Nitrates, and Sulfates conformed international standards which makes the water suitable for reuse. However, due to the exceeded turbidity and chloride levels found in the greywater, targeted treatment procedures are necessary for its reuse in irrigation. All samples were found to be contaminated with fecal matter (10⁴ CFU/100 ml) and total coliform (1100 CFU/100 ml) that could cause diseases. In this regard, the chapter further reviews low-cost treatment systems from Kenya, India and Egypt which could be used in a developing country like Bangladesh. Moreover, this chapter gives recommendations for proper management approaches towards greywater reuse.