Groundwater Resource Assessment for Town Water Supply in South Africa. The Case of Steynsrus in the Free State Province

Master's Thesis from the year 2016 in the subject Geography / Earth Science - Geology, Mineralogy, Soil Science, grade: 3.4, University of the Free State (Institute for Groundwater Studies), course: Geohydrological Masters Programme, language: English, abstract: Groundwater resource assessment aims to obtain fundamental data and information needed to describe the hydraulic and chemical parameters in order to estimate the available groundwater resource which is suitable for drinking. This study was undertaken with the purpose of determining and estimating the groundwater occurrence, groundwater flow parameters, groundwater quality and storage in typical Karoo Main Basin aquifers such as in the Steynsrus study area in South Africa. The field investigations were designed to define and determine the sustainable yields and the properties of the aquifers and the exploitable volumes. The research places emphasis on the appropriate tools and their applications in order to understand the local aquifers so as to optimise the groundwater exploration for town water use and to determine the future water use. The geophysical surveying methods, particularly the magnetic method, were utilised to investigate and determine borehole drilling targets, and to locate groundwater potential structures, which are often associated with high borehole yields. The quality of the magnetic data utilised for drilling by the external consultant was critically evaluated and was found to be 'bad data'. Percussion drilling played an important role in providing geological subsurface information; in particular locations of fractures which are often associated with favourable groundwater flow were identified. Seventeen (17) boreholes were drilled in the whole project, seven (7) of the boreholes were sited by magnetometer survey and interpretation, and ten (10) of the drilled boreholes were sited by geological mapping and map interpretation. Twelve of the drilled boreholes were declared 'unsuccessful' due to yielding a blow yield below 1.00 L/s; therefore these boreholes were not considered for aquifer pump testing. Blow yields of five (5) of the newly drilled boreholes were between 1.5 and 24 L/s. Based on these findings, the aquifers in the study were concluded to be a fractured system of alternating layers of sandstone and shale formations, characterised by the favourable groundwater flow characteristics at the dolerite fractures, and in some cases bedding plane fractures of sandstone formations. The study demonstrates the value in the methods and concepts applied in geohydrological studies to understand the local aquifer properties and in order to estimate the sustainable yields and the groundwater balance.

My name is Lebogang Malefane, a son of Mosotho woman and Xhosa man. I was raised in a single-mother home with two sisters siblings, and one younger brother. I was born in Mafikeng in the former Bantustan, Bophuthatswana, under the presidency of the late Dr. Lucas Mangope. My journey as a curious mind was shaped by my background and challenges I endured as I grew with time. I managed to complete my studies in Chemistry, later obtained Geohydrology honours degree and took on a Masters research, which I completed in 2016. My working experience started as a junior in a Project Management field which prioritised service delivery via buld infrastructure projects that include groundwater development for towns and villages that do not have access to any other water source. Later progressed into a role where I was fulfilling compliance monitoring and enforcement responsibilities. I am currently an advisor for drafting of regulations on unconventional gas activities in South Africa. I have dreams and goals to have more impact in decision making of public sector or any organisation that seeks to use the skills and talents I possess to advance business and goals.