Multi-Criteria Analysis of Suitable Sites for Sanitary Landfill Development in Kaduna State

Uncontrolled and poorly sited waste disposal facilities across Nigerian states generate significant environmental and public health risks, and the identification of environmentally suitable sanitary landfill sites through systematic spatial analysis represents an urgent planning priority. This study applies multi-criteria analysis within a geographic information systems framework to identify and rank suitable sites for sanitary landfill development across Kaduna State, North West Nigeria. Eight siting criteria derived from the Nigerian Environmental Impact Assessment Act, Federal Ministry of Environment Guidelines for Sanitary Landfill Siting, and international best practice are operationalised as spatial data layers: distance from surface water, soil permeability, slope gradient, distance from settlements, distance from airports, geological suitability, land use compatibility, and road accessibility. Analytical Hierarchy Process weighting was determined through expert consultation with six environmental practitioners and three academic specialists. Weighted overlay analysis produced a statewide suitability surface classified into five categories. The suitability model was validated against the known locations of three existing managed disposal sites, all of which fall within high to very high suitability zones. Findings identify 23 candidate suitable sites distributed across 14 Local Government Areas, covering a combined area of approximately 840 hectares. Six priority sites are recommended for detailed ground investigation, two of which are located in LGAs currently lacking any formal waste disposal facility. The study provides a replicable methodology for other Nigerian state environments planning authorities. Keywords: sanitary landfill siting, multi-criteria analysis, GIS, Kaduna State, waste disposal planning.