Urban wastewater management in Nepal: generation, treatment, engineering and policy perspectives

Abstract

Rapid urbanization has caused a worldwide increase in the discharge of wastewater effluent. Although Nepal has a noteworthy history of wastewater management, progress in this field has been hindered by persistent issues. These problems encompass insufficient sewer coverage, deficient treatment and sludge disposal facilities, inadequate treatment infrastructure, lack of coherent institutional frameworks, and a lack of comprehensive planning. This review provides a glimpse into Nepal's current urban wastewater landscape while also offering a concise historical overview of its wastewater management trends. The study gathered data, information from government organizations, as well as related research, review articles, and reports from 1999 to 2023. Our findings reveal that more than 85% of urban households in Nepal rely on onsite sanitation, with limited access to septage treatment facilities. The ratio of wastewater treatment to generation is disconcertingly low, further emphasized by the concentration of centralized treatment plants in the capital city. This low ratio underscores the inadequacy of the existing wastewater system and the novice approaches of the government, which contribute to the poor sewerage facilities in Nepal. This study unequivocally highlights the imperative need for functional and institutional hierarchy emphasizing local communities, substantial changes in resource allocation, governance practices, and technical infrastructure. HIGHLIGHTS Nepal is struggling with urban wastewater challenges due to a lack of infrastructure.; Over 85% of urban households are mainly relying on onsite sanitation systems.; Two of seven provinces provide public sewerage systems covering about 10% of the total households.; Advanced treatment technologies are suggested in conjunction with conventional ones.; Proper resource allocation, good governance, and technical skills enhancement are urgent in countries like Nepal, to achieve SDG-6.;

Keywords

• nepal
• urban wastewater
• wastewater management
• wastewater treatment