Assessment of Municipal Wastewater Treatment Plants in Addis Ababa: Operational Status, Challenges, and Technological Performance

Wastewater management in Addis Ababa faces critical challenges driven by rapid urbanization and population growth, resulting in the discharge of untreated wastewater into local water bodies. This pollution poses severe threats to aquatic ecosystems, diminishes biodiversity, and disrupts ecological balance. To address these issues, this study conducts a comprehensive assessment of the city’s municipal wastewater treatment plants (WWTPs), with a focus on their operational status, factors influencing functionality, and the effectiveness of the employed treatment technologies. The research adopts a structured methodology, employing both random and purposive sampling techniques to select 110 participants from a total population of 320, encompassing 11 WWTPs. Data were collected through structured questionnaires and semi-structured interviews, and analyzed using SPSS and Microsoft Excel. Results are presented using descriptive statistics, tables, and charts. Preliminary findings reveal that out of the 11 WWTPs, only 10 are currently operational, while one remains non-functional. Key factors undermining technological efficiency include poor maintenance, limited budgets, outdated technologies, population pressures, frequent power outages, unavailability of spare parts, and low public awareness. Additional challenges involve odor control, insufficient staff training, sludge management difficulties, equipment failures, and inadequate safety measures. The treatment infrastructure consists of two Up flow Anaerobic Sludge Blanket Reactors (UASBRs) and nine Membrane Bioreactors (MBRs), all operating at below 50% of their designed capacity.