Potential groundwater pollution from improper oil and metal waste disposal in Suame, Ghana

Abstract

Suame is an industrialized hub in Kumasi, Ghana, that is noted for vehicle repairs and servicing, sale of automobile spare parts, and metal fabrication. Some of these activities generate huge volumes of waste oil and metals that are often disposed off indiscriminately into the environment. These could pose a threat to the quality of groundwater in the area, especially if they continuously accumulate in the environment. This study, therefore, investigated the potential impact of the waste disposal on groundwater quality in the area. The methods employed involved mapping all the potential waste oil spillage sources and sampling the soils in such areas (at 0 – 30 and 30 – 60 cm depths) and groundwater supply points for laboratory analyses to determine the presence of the waste. In all, 36 samples (comprising 12 soil and 24 groundwater) were analysedfor the presence of heavy metals including Cd, Ni, Cu, Pb, Zn and Cr, which were used as traceelements for the presence of the waste in the samples. Computedgeo-accumulation indices from the results show the soils are moderately to heavily polluted with Cd and Pb whilst the groundwater, when compared to the WHO drinking water guidelines, is polluted with Pb and Ni. Althoughthe source of the high Pb content observed could be attributed to its transport directly from the activities in the area, the presence of high Ni makes it inconclusive since the Ni in the soil was within the concentration expected of the parent rock geochemistry. This notwithstanding, the study has indicated that groundwater in the area is not safe for human consumption unless the lead and nickel concentrations are reduced to acceptable standard for drinking.Keywords: Groundwater quality, pollution, waste disposal, Suame, Ghana