Life-Cycle Cost Analysis and Financial Sustainability of Fecal Sludge Management in Vientiane Capital, Lao PDR

This study evaluated the life-cycle cost and financial sustainability of a fecal sludge management system using planted drying beds and constructed wetlands in Vientiane Capital, Lao PDR, with a focus on resource recovery from sludge-based fertilizers. Primary data were obtained from semi-structured interviews with key stakeholders and multi-year operational and financial records, complemented by regional benchmarking against com-parable systems in Southeast Asia (SEA). A 15-year life-cycle cost analysis, applying dis-count rates of 3–7% and inflation rates of 3–5%, encompassed capital, opera-ton-and-maintenance, replacement, and end-of-life costs, alongside a sensitivity analysis of key cost and revenue drivers. The system’s annualized cost of USD 237,072 contrasts with revenues of USD 100,822 per year from treatment fees and fertilizer sales, leaving a persistent financing gap of USD 136,250 per year (57.5% of total costs). Although unit treatment costs fall within the regional mid-range, the cost recovery rate of 42.5% is 1.2–1.8 times lower than that in comparable Southeast Asian cities, where cross-subsidies via water bills, stronger regulatory enforcement, and more mature fertilizer markets improve financial performance. The findings indicate that resource recovery alone cannot ensure financial self-sufficiency and highlight the need for integrated financing strategies, regulatory reforms to increase regular fecal sludge emptying, and expanded markets for re-source recovery products.