Economic analysis and probability of benefit of implementing onsite septic tank and resource-oriented sanitation systems in Seoul, South Korea

Abstract

Most sanitation provisions cater to toilet infrastructures alone. Little consideration is given to requirements before and after toilets, such as the availability of water supply along with safe and sustainable methods for the disposal, treatment, and recycling of sanitary wastes after the toilet. Implementing communal onsite sanitation practices can be more feasible for societies suffering from a lack of adequate sanitation systems. This study presents a lifetime cost analysis of two onsite sanitation systems, one septic tank, and one resource-oriented sanitation (ROS) system. Both systems are considered to be implemented in a suburban area of Seoul to offer public hygiene services. The lifetime cost and probability of benefit were evaluated based on the capital, operation, maintenance, and disposal costs for one year. Results show that although the septic tank sanitation system requires a lower initial capital cost, its annual operation and maintenance costs are higher than the ROS systems'. The economic analysis shows how ignoring pre-toilet and post-toilet infrastructure can mislead the decision-making process by resulting in a higher capital and maintenance cost for the ROS system. Accordingly, the sanitation system should be considered not only to be a toilet but also to contain the required pre-toilet and post-toilet steps.