Assessment of Groundwater Quality in Owerri and Its Environments, Southeast Nigeria

Abstract

Physico-Chemical and bacteriological characteristics of eleven boreholes located within Owerri city were examined. The bacteriological analyses were carried out using the method of inoculation and incubation of specimens and counted on colonies. Titration method was used to determine chlorides and nitrates while Cu2+, Zn2+ and Mn2+ used atomic absorption spectroscopy (AAS). Iron concentration was read off using benzylideneacetone (BDA) Lovibondcolour comparator while the total dissolved solids were determined gravimetrically. The water is usually clear at average temperature of 27˚C. The bacteriological parameters are within the acceptable World Health Organization (WHO) standard and safe for human consumption. The pH is 6.0 -7.5, total dissolved solids vary from 12.4mg/l to 49.4mg/l. The anions of chloride and nitrate are 67mg/L to 125mg/L and 0.003 mg/L to 23.1 mg/L respectively. Concentrations of cations include iron; 1.86mg/l, copper; 1.2mg/l, zinc; 2.1mg/l and manganese; 0.05mg/l. The results show that the groundwater within the city is suitable for drinking and other uses compared to the WHO standard. The environmental conditions of the borehole locations as well as the total drill depth should be emphasized. Government monitoring agency should ensure adequate drill depth to at least 200ft in the south- western area and north- eastern areas from 250ft to 300ft as this may reduce the injurious variations in the geochemical parameters in some boreholes.