Benefit-cost analysis of faecal sludge management options in peri-urban area

Abstract

Septic tank has been widely used in urban and more popular in peri-urban areas in Vietnam. That leads to more and more amount of septic sludge, which has been created. Faecal sludge management (FSM) is a big challenge in today's rapid urbanizing Vietnam. More than 50% of household with farming activities wish to reuse sludge for garden or crop. There are many options of FS treatment such as drying bed, dewa­tering, anaerobic digestion, co-composting or vermicomposting, in which FS treatment integrating into existing farming will be feasibility option. In order to better understand a) household demand for emptying services; b) costs of desludging services, particularly with respect to transport; c) drivers of private sector participation the sanitation value chain; and d) treatment and safe disposal/reuse of sewage, a Benefit Cost Analysis (BCA) study on FSM models have been conducted to compare treatment, disposal and reuse options. BCA result shown that inner return rate (IRR) of FS private emptier, household with farming activities and FS feeding worm farm are 8%, 14% and 207% respectively. It also shows that vermicomposting business is promising option for FS treatment in order to safe reuse of FS and nutrient recovery.

Keywords: Benefit-cost analysis, faecal sludge, nutrient source, vermi-composting.

Received: October 5th, 2017; revised: October 27th, 2017; accepted: November 2nd, 2017