Located in the North-Western part of Ghana, the town of Wa (See Figure 1) is the administrative capital for Wa Municipality. The town is centrally located around latitude 10˚3.76'N and longitude 2˚29.884'W with characteristic radial growth. The Wa Municipality is part of the eleven (11) municipal and districts of the Upper West Region of Ghana. It is bordered to the north by the Nadowli and Daffiama-Bussie-Issa Districts, to the east and south by the Wa-East District, to the south by the Sawla-Tuna-Kalba District, and to the East by the Wa-West District. Wa also functions as the administrative capital of the Upper West Region, which shares boundaries with Burkina Faso, and Cote d’Ivoire in the north and west, and the Upper East and Northern regions of Ghana in the east and south, respectively. The town of Wa’s population was projected to be 81,725 in 2012 [10] .

The Environmental Health and Sanitation Unit of the Wa Municipal Assembly (EHSU), is the local Authority’s unit that has responsibility to manage MSW in Wa and the entire Municipality. The Authors interviewed the Unit and obtained the following information about MSWM in Wa town:

・ Wa produces approximately 20,000 tons of MSW annually, based on 0.45 kg/capita generation rate.

・ This amount of MSW is composed of metals, paper and cardboard, organics (including food and wood wastes), plastics, textiles, inert substances (sand and ashes), and waste electric and electronic equipment.

・ About 13,400 tons (68%) of MSW is collected annually in the town and over 80% of that collected using the communal container collection system (see Figure 2) while the remaining is collected through house-to- house system.

・ The communal containers used have an average capacity of 15 m³ each.

・ The EHSU estimates that over 80 communal containers would best serve the municipality but they provided only 37. This few number of containers and inefficient empting of the containers result in heaps of wastes at most of the sites.

・ The EHSU have inadequate number of equipment and machinery.

・ The over 30% of uncollected MSW find its way into the environment through littering, burning, and indiscriminate dumping in open spaces and streams/waterways.

・ The municipality’s final disposal site with an area of about 0.25 km² is located at Siriyiri, a small community about 5 km to the west of Wa. This site is not engineered to reduce the risk of environmental pollution.

The main source of drinking water for Wa is from the Ghana Water Company Limited (GWCL). Through the Ghana Urban Water Supply strategy, Wa water demand should fully be met by an urban water company like the GWCL. However, a significant proportion of residents depend on boreholes and hand-dug water wells for their domestic water needs due to insufficient water supply. Estimates of current potable water demand by the town is around 15,000 m³ per annum, however, the GWCL is capable of supplying only about 1400 m³ [11] . Thus water rationing is common and residents are forced to rely on alternate sources of water such as boreholes and hand-dug wells to meet water needs.

The data collection for this study was carried out in Wa from June to August 2013 for both MSWCS and drinking water collection sources (i.e. boreholes and hand-dug wells) using a GPS receiver, GPSMAP 62sc, a product of Garmin. The data were then transferred to ArcMap 10.1 (ArcGIS 10.1) software with the aid of DNRGPS software. The layers were projected into WGS 1984 UTM Zone 30N. Relevant attributes (Table 1) were recorded for the MSWCS and drinking water collection sources using data collection sheets. Areas with open, indiscriminate dumps were noted during field visits.

Two hard copy topographic maps for Wa with a scale of 1:50,000 and Ghana National Grid projection were scanned and georeferenced in ArcMap 10.1. The maps were merged and essential features including roads, reservoirs (dams), and communities digitized in ArcMap. The land use polygon and streams/waterways layers were obtained from Center for Remote Sensing and Geographic Information Services (CERSGIS), University of Ghana and these layers were processed in ArcMap to reflect the extent and current conditions in the study area.

A total of 51 MSWCS (37 containers and 14 open dumps) were identified in Wa town through the mapping. The resulting feature layer was employed to develop a MSWCS map (Figure 4). As is obvious from Figure 4, the MSWCS are concentrated within the middle of the town. This pattern may be due to the high density population

in town compared to peri-urban areas. Also, it is visible from Figure 4 that from around the middle of town and moving toward west there are virtually no MSWCS. This is expected because this section of the town hosts government buildings including offices, schools, and residential apartments. It is among the few places with house-to-house services that were noted in the field.

MSWCS geodatabase, which can help in planning and management decision making on MSW, is non-exis- tent in Wa. Thus, the creation of this database should be a useful tool toward improving the MSW collection system in Wa Municipality. Further, the accompanying spatial map can be utilized by MSW managers to easily visualize where to direct clean-up programs as well as locate new containers in Wa town [4] [12] .

The results of this analysis are shown in Figure 5. Out of the 51 MSWCS mapped, 17 (about 34%) had containers and no ground dumping of waste, 20 (39% approximately) had containers with ground dumping of waste, and 14 (nearly 27%) are without containers with ground dumping. Overall, about 67% of MSWCS are experiencing ground dumping, which suggests poor MSWM.

The 14 sites experiencing open dumping appear relatively located out of inner town suggesting that the collection system is mostly concentrated in the inner city. Records from the waste managers (EHSU and Zoomlion Ghana Limited) of Wa Municipality showed that 37 container sites were in the town. It may be that these managers are not aware of the dumping going on in most of the 14 sites without containers. This map and its relational database could be a great resource to help these waste managers identify the 14 sites for proper management. Further, the 20 sites with containers and ground dumping are an indication that those sites have inadequate containers and may need additional containers to eliminate or minimize ground dumping. Though we lacked adequate resources to quantify ground dumping during the field survey, it is worth noting that dumped waste range from young to matured and low to relatively higher in volume.

With the MSWCS as potential contaminant sources, we run the GIS model for the 30 meters minimum distance requirement in the LI 1827 and no result was obtained. This finding suggests that all the handpump boreholes mapped in this study met the minimum 30 meter requirement for siting boreholes with respect to the MSWCS as possible contaminant sources. This implies that the MSWCS may not pollute the handpump water sources per the requirement of LI 1827. However, when the model was run for mechanized boreholes with minimum distance of 100 meters, 15 outputs (24% of mechanized or 15% of total boreholes) were generated. These results do not suggest that the affected boreholes must be decommissioned, but to indicate the need for effective MSWM in order to reduce any potential impact on water sources, since the town is not adequately served with potable water by the GWCL. Further, it must be noted that siting of most of these boreholes predates LI 1827 which was promulgated in 2006, and the regulations appear silent on the fate of existing boreholes as regards environmental protection. Hence, these regulations may not be used for enforcement actions on existing boreholes without further directions from the Ghana Water Resources Commission who has the responsibility to implement the law. However, monitoring of the water quality of the identified boreholes may be required to ensure the water meet drinking water quality requirements. This model can be replicated in other parts of Ghana to establish the proximity of boreholes to potential contaminant sites using the appropriate geodatabases. Recommendations can then be made for effective protection of the borehole drinking water sources from impacts of the potential contaminant sources.

Results from Figure 6 show high pollution risk zones located within high density built up areas of the town, with no or little open space land. Thus, alternative indiscriminate dumping of MSW within the reserved banks of rivers, streams, wetlands, and watercourses was most likely the practice adopted by nearby residents. Conversely, low density settlement areas were observed to have low indiscriminate dumping and hence were given low pollution risk ranking.

It appears low lying watercourses and stream banks were most patronized for construction of hand-dug wells. As is visible from Figure 6, most of the hand-dug wells mapped were located within these areas. Out of the 18 hand-dug wells, 14 (about 78%) were found within the pollution risk zones. This suggests that potential pollution of the wells is high, particularly so because of the high water tables and inadequate protection observed for some wells during the field mapping. Using such wells as potable water sources may expose residents to high health risks, although water quality analysis may be required to establish actual pollution. Nevertheless, alternative improved water sources need to be provided for households depending on these wells to prevent any eventuality.