Assessment of Heavy Metal Contamination in the Weija Dam, Ghana

Abstract

This study was conducted to assess heavy metal contamination (Fe, Pb, Cd and Mn) in water and sediments from the Weija dam. It was carried out in March 2014, representing the dry season and August 2014, representing the wet season at ten (10) sampling Sites. Water and sediment samples were taken from ten different Sites within the Weija dam in March, 2014 (dry season) and August, 2014 (wet season). Heavy metal concentrations were determined using atomic absorption spectrophotometer (AAS). In the dry season, mean concentration of heavy metals in the water were 0.03 mg/L(Fe), 0.02 mg/L (Cd), 0.03 mg/L (Mn) and 0.02 mg/L (Pb) while in the wet season, the mean concentrations were 0.28 mg/L (Fe), 0.00 mg/L (Pb), 0.02 mg/L (Cd) and 0.03 mg/L (Mn). Levels of all heavy metals were below the WHO guideline values for drinking water. All the metal concentrations in the sediment were higher than that of the water samples in both dry and wet seasons.  The concentrations of all the metals studied were below USEPA guideline values. Results   of Pollution Indices computed namely, Concentration factors (C_f), Geo-Accumulation Index (I-Geo)Pollution load Index showed no pollution. The results from this study therefore showed that the water in the Weija dam is relatively clean with regard to the measured heavy metals.

Keywords: Weija dam, water, sediment, heavy metals, seasonal variation Concentration factors, Geo-Accumulation Index, Pollution load Index.