ASSESSMENT OF WATER QUALITY STATUS AND HEAVY METAL CONTAMINATION OF THE BAREKESE RESERVOIR IN THE ASHANTI REGION OF GHANA

The Barekese reservoir is a facility for reserving water for treatment and subsequent distribution to the Kumasi metropolis and its environs in Ghana. Over the past two decades the reservoir has encountered persistent degradation through anthropogenic activities along its catchment area which has raised concern on the deteriorating water quality. Water samples were collected in 1 litre bottles from January to June, 2014 to assess the impact of anthropogenic activities along the reservoir and its catchment area. The objective of the study was to determine the water quality status and extent of heavy metal contamination of the reservoir. The temperature, electrical conductivity and pH were measured in-situ at the point of collection. The chemical characteristics including heavy metals were determined in the laboratory using the standard methods for examination of water. The results showed that the colour and turbidity ranged between 18 to 49 Hz and 2.96 to 8.18 NTU, respectively as compared to WHO acceptable limits of 15- 25 Hz and 5NTU for colour and turbidity. The concentrations of Mn (0.02±0.01 mg/l), Zn (0.08±0.03 mg/l), and Cu (0.004±0.002 mg/l) were also within the WHO limits. However the concentrations of Fe, Ni and Cr exceeded the WHO limits with values of 3.14±0.24 mg/l, 0.30±0.12 mg/l and 0.05±0.012 mg/l respectively. Total coliform count, was 84.40±23.89 CFU/100mL which was higher than the WHO acceptable limit of 0.00 counts/100 mL. All the physico-chemical parameters except for colour and turbidity were comparatively within the WHO recommended limits. To control the degradation of the water quality of this important resource efforts should be made to reduce mining, dumping of municipal waste, lugging and other anthropogenic activities along the reservoir and its catchment areas.