Urban Hydrogeological Studies of Groundwater in Central University of Technology Bloemfontein Campus

Abstract

Groundwater within the Central University of Technology (CUT), Bloemfontein, was investigated in order to determine its hydraulic and hydrochemical characteristics with potentials for urban water supply. The investigations involved carrying out pump yield tests on three boreholes on the CUT campus. Further examination involved laboratory testing of the groundwater for chemical signature, and geophysical investigation to determine the geological and aquifer target of the boreholes using an electrical resistivity tomography (ERT). Additionally, electrical conductivity profiling (EC Profiling) was used to detect the fracture positions within the boreholes. Pumped test results monitored from the three boreholes were interpreted using FC (flow characteristics) software program. Cooper-Jacobs and Basic FC methods from this software recommend a sustainable yield of 7.83–9.34 l/s, respectively, while storativity values are 7.93 × 100 for Cooper Jacobs and 2.2 × 10−3 for Basic FC method. Hydrochemical analysis shows Mg-HCO3 water type from Stiff diagram. This shows dissolved solutes from rainfall and the host rocks, but not from urban activities. The results of the fracture positions at an ambient state in the wells were 5, 6 and 9.5 mbgl in boreholes 1, 2 and 3, respectively. The geohydrological characteristics displayed by the groundwater of the CUT campus relate to the general characteristics of the Karoo aquifers.