Assessment of groundwater quality in wells within the Bombali district, Sierra Leone

Abstract

This study assessed the quality of 60 groundwater wells within the Bombali District of Sierra Leone. Water samples from the wells were analysed for physical (temperature, turbidity, conductivity, total dissolved solids and salinity), chemical (pH, nitrate-nitrogen, sulphate, calcium, ammonia, fluoride, aluminium, iron, copper and manganese) parameters using potable water testing kit; and bacteriological (faecal and non-faecal coliforms) qualities. Results show that 73% of the samples had turbidity values below the WHO, ICMR and United USPHS standards of 5 NTU. The electrical conductivity (mS/cm) of 5% of the whole samples exceeded the WHO guideline value, 8% of the entire samples had values higher than the WHO, ICMR and USPHS recommended concentration. In terms of iron, 25% of all the samples had values in excess of WHO, ICMR and USPHS recommended value of 0.3mg/l. For manganese, 12% of the entire samples had values more than the WHO and ICMR standards. On the other hand, more water samples (22%) had manganese values above USPHS guideline value. For bacteriological quality, 28% of the wells were polluted by faecal and non-faecal coliforms. 60% and 40% of the entire samples had faecal and non-faecal coliforms respectively above the WHO standard. Remedial measures recommended include regular monitoring of the physico-chemical and bacteriological quality of water yield from these
wells as well as teaching of the communities' basic sanitation and hygiene practices.

Keywords: Groundwater quality, Well waters, Physical, chemical and biological characteristics, Sierra Leone