Analyzing the Effect of Wastewater on Groundwater Quality, in case of Bahir Dar, Ethiopia

Abstract Most residential and institutional centers in urban areas provide on-site sanitary facilities for waste management, such as septic tanks and conventional pit latrines, to collect and dispose of the generated human wastes. The most difficult problem in Bahir Dar City is the influence of these human waste management sanitary structures on groundwater quality, which has recently become a major concern in most developing countries, including Ethiopia. Twelve (12) shallow groundwater wells were selected purposively throughout the city in order to assess the pollutant concentration and its impact on groundwater quality. Temperature, pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), chloride, nitrate, phosphate, total hardness, and Escherichia coli (E. coli) were all measured in the collected groundwater samples both in situ and in the lab. To determine pollutant sources and levels of compliance with particular water quality criteria, differences in groundwater quality parameters between the measured stations were examined. In all sampled stations, the study's overall findings revealed that E. coli concentration levels exceeded the WHO threshold, and shallow wells next to on-site waste management facilities are completely contaminated. The results of this study will generally aid in the future development of the best groundwater quality management strategies and methods for implementing corrective actions to avoid groundwater quality issues.