Multi-Criteria Decision Making for Site Selection of a Solid Waste Disposal Facility in Borno State

The proliferation of unmanaged solid waste in Borno State, North East Nigeria, particularly in the aftermath of displacement crises, poses grave public health and environmental risks. This study applies multi-criteria decision making (MCDM) techniques, specifically the Analytic Hierarchy Process (AHP) and TOPSIS, to identify the optimal site for a regional solid waste disposal facility in Maiduguri and its environs. Seven candidate sites are evaluated against ten criteria spanning environmental suitability, hydrogeological safety, proximity to population centres, land cost, road accessibility, social acceptability, and proximity to water bodies. Criteria weights are established through structured pairwise comparisons with a panel of environmental engineers, urban planners, and community representatives. TOPSIS is then applied to rank the candidate sites based on their relative closeness to the ideal solution. Results from both methods converge on the same top-ranked site, providing high confidence in the recommendation. Sensitivity analysis demonstrates that the ranking is stable under moderate variations in criteria weights, with the exception of the social acceptability criterion where community input is polarized. The study recommends site one as the preferred location and prescribes an environmental impact assessment as a mandatory precondition for site development. This research contributes a structured decision support methodology for waste infrastructure planning in post-conflict and resource-constrained contexts in North East Nigeria. Keywords: multi-criteria decision making, AHP, TOPSIS, solid waste management, Borno State