Chemical quality of groundwater drawn from boreholes in the Ashanti Region of Ghana

Abstract

In the Ashanti Region of Ghana, the physicochemical quality of groundwater sampled from 38 wells in 24 communities in Ejisu-Juaben and Bosomtwi-Atwima- Kwanwoma districts was surveyed between November 2004 and June 2005. Water samples were analysed for pH, electrical conductivity (EC), SO 4 2-, CI, PO 4 3-, NO 2 -, Fe, Mn, Cu, Zn, Cd, Na, K and Pb. The results revealed wide variations in analysed parameters: pH (4.0-8.0); EC (44-1110 μs-cm -1), turbidity (0.1-45 NTU), colour (<5-60 HU), hardness (3-400 mg CaCO 3·L -1), alkalinity (10-365 mg CaCO 3·L -1), CI -1 (5-92 mg·L -1), SO 4 2- (0.5-17 mg-·L -1), PO 4 3- (<0.01 to 2.4 mg·L -1) and NO 2'(<0.01 to 0.08 mg·L -1). Elemental concentrations were Fe (0.06-3.4 mg·L -1), Mn (<0.01-1.6 mg·L -1), Cu (0.01-1.3 mg·L -1), Zn (<0.01-3.3 mg·L -1), Cd (<0.001-0.006 mg·L -1), Pb (<0.001-0.038 mg·L -1), Na (4-87 mg·L -1) and K (0.2-80 mg·L -1). With the exception of isolated cases of trace metal contamination and turbidity, water from the boreholes in the two districts had acceptable quality for domestic use. Copyright © 2009 IAHS Press.