Waste Management & Research 2016, Vol. 34(10) 1054–1063 © The Author(s) 2016 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0734242X16658363 wmr.sagepub.com Introduction Municipal solid waste (MSW) is generated by households, busi- nesses, institutions and industry. MSW typically contains a wide variety of materials including discarded containers, packaging, food wastes and paper products. It includes a mixture of putresci- ble (easily degradable) and non-putrescible (inert) materials (USEPA, 2002). Management and disposal of such waste is a major challenge worldwide, particularly in highly urbanized areas and in developing countries (Washburn, 2012). Despite significant efforts made by some countries in recent decades to improve solid waste management services, most municipalities and metropolitan cities in developing countries still face major challenges in prop- erly handling the increasing volume of waste produced. Increasing population, economic activities, urbanization and industrialization especially in developing countries such as those in Africa, have drastically increased the amount of waste generated. Over the years, due to rapid urbanization, many existing dis- posal sites have been encircled by settlements and housing estates. The environmental degradation associated with these dumps directly affects the population with the consequence that disposal sites are subject to growing public opposition. This, together with the unavailability of land, is one of the reasons why obtaining sites for new landfills is becoming increasingly difficult. Finding a site for a new landfill far away from the urban area may have the advantage of less public opposition. However, it also means that the site is far away from the source of waste generation, thus increasing transfer costs and needing additional investments in the infrastructure of roads, hence intensifying the financial problems of the responsible authorities (Zurbrügg, 2002). A waste transfer station is an important component of a waste management system and functions as a link between a commu- nity’s solid waste collection program and a final waste manage- ment system. There may be significant differences in the facility size, ownership and services offered but the basic purpose is to consolidate waste from multiple collection vehicles into larger long-haul vehicles for more economical shipment to a final waste management system. The basic type of transfer station has a des- ignated receiving area where waste is unloaded, often compacted and reloaded into larger high volume vehicles, usually in a matter of hours (Öberg, 2011; USEPA, 2002). Bovea et al. (2007) described waste transfer stations as an integral part of present- day MSW management systems. The main criteria used to decide on the location of a transfer station has traditionally been the minimization of transport costs, as it is cheaper to transport great amounts of waste over long distances in large loads compared with small ones. Where the distance from the waste collection area to the waste treatment facility is large, a transfer station may be used to bulk up the waste for more efficient transport by a Multi-criteria GIS-based siting of transfer station for municipal solid waste: The case of Kumasi Metropolitan Area, Ghana Christian Bosompem 1 , Eric Stemn 2 and Bernard Fei-Baffoe 1 Abstract The increase in the quantity of municipal solid waste generated as a result of population growth in most urban areas has resulted in the difficulty of locating suitable land areas to be used as landfills. To curb this, waste transfer stations are used. The Kumasi Metropolitan Area, even though it has an engineered landfill, is faced with the problem of waste collection from the generation centres to the final disposal site. Thus in this study, multi-criteria decision analysis incorporated into a geographic information system was used to determine potential waste transfer station sites. The key result established 11 sites located within six different sub-metros. This result can be used by decision makers for site selection of the waste transfer stations after taking into account other relevant ecological and economic factors. Keywords Municipal solid waste, waste transfer station, multi-criteria decision analysis, GIS, waste management system, selection criteria 1 Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana 2 Environmental and Safety Engineering Department, University of Mines and Technology, Tarkwa, Ghana Corresponding author: Eric Stemn, Environmental and Safety Engineering Department, University of Mines and Technology, PO Box 237, Tarkwa, Ghana. Email: estemn@umat.edu.gh 658363WMR 0 0 10.1177/0734242X16658363Waste Management & ResearchBosompem et al. research-article 2016 Original Article