GIS-aided optimisation of faecal sludge management in developing countries: the case of the Greater Accra Metropolitan Area, Ghana

This study employed GIS tools to help optimise faecal sludge (FS) management in the Greater Accra Metropolitan Area (GAMA) and its environs in Ghana. First, the rates of excreta generation, FS generation and FS collection were quantified based on literature, census and FS discharge data obtained from treatment plants in the study area. Next, we mapped the FS collection to the administrative areas in GAMA based on discharge records obtained from Lavender Hill, the main faecal treatment (FTP) and estimated the travel distance and travel time from the various FS desludging neighbourhoods to the plant. The results of the study show that the excreta and FS generation rates in GAMA are 604 L/cap/yr and 4,137 L/cap/yr, respectively. About 1 million m³ of FS was collected and treated in the study area in 2018, with a collection rate of 244 L/cap/yr. The private sector dominates this collection, haulage and treatment of FS in GAMA. The GIS analysis has provided fundamental data that will be useful in rationalising the FS emptying and transport cost in the study area. Moreover, it revealed that about 20–40% of the localities were outside the 15–25 km sustainable maximum transport distance recommended by some scholars. Finally, the findings highlight the importance of looking beyond administrative boundaries when planning for FS management logistics and infrastructure and also show that the most impoverished communities in the Accra metropolis may not necessarily be the least served when it comes to FS collection and haulage.