Agent-Based Modelling for Simulation-Based Design of Sustainable Faecal Sludge Management Systems

Area of Science:

• Environmental engineering
• Urban planning
• Computational social science

Background:

• Faecal sludge (FS) reuse offers potential for sustainable sanitation in urban sub-Saharan Africa.
• Existing systems lack tools to model economic, social, and environmental factors in FS reuse.
• Agent-Based Modelling (ABM) is proposed as a suitable simulation tool.

Purpose of the Study:

• To develop and demonstrate the utility of Agent-Based Modelling (ABM) for simulating faecal sludge (FS) management systems.
• To investigate the adoption of composting toilets and the operation of municipal FS sites.
• To inform the design of effective FS reuse strategies.

Main Methods:

• Extensive fieldwork in a Malawian city, including 65 semi-structured and 148 household interviews.
• Development of two distinct Agent-Based Models (ABMs): one for composting toilets (Skyloo) and one for a municipal FS site.
• Simulation of various scenarios, including business start-up capital, loan payback, dumping fees, and enforcement structures.

Main Results:

• Fieldwork confirmed potential for expanded FS reuse, particularly for agricultural applications.
• The Skyloo ABM highlighted the critical role of start-up capital for businesses.
• The municipal FS Site ABM indicated current fee structures were ineffective against illegal dumping, but a permit system could increase revenue.

Conclusions:

• Agent-Based Modelling (ABM) provides a novel framework for simulation-based design of faecal sludge (FS) management systems.
• ABM effectively integrates complex social, economic, and environmental factors into system design.
• The study demonstrates ABM's potential for optimizing sanitation solutions in urbanizing regions.