A theoretical analysis of possible geohydrological impacts associated with proposed hydraulic fracturing activities in the Karoo Basin of South Africa

Abstract

The decision to allow HF within the Karoo Basin of South Africa has raised many valid concerns regarding possible impacts on shallow groundwater resources upon which many communities and farmers are reliant to provide for their families. Due to huge uncertainties on deep aquifer and groundwater behaviour, as well as possible long-term impacts because of HF, this thesis includes research and results focusing on the following two aims: 1. To evaluate possible impacts on shallow groundwater resources/aquifers in the Karoo; and 2. To produce a Groundwater Risk Assessment Tool (GW-RAT) that will assist decisionmakers on quantifying possible risks to the groundwater regime at a specific location. Internationally it is very difficult to quantify environmental impacts specifically on shallow groundwater resources due to a lack of information. No baseline information is available and many claims could not be validated due to this issue. In South Africa we have an opportunity to address this information gap that exists in the USA and Canada and it is critically important that regulators and government see to it that a database be created before any licences are awarded. It is evident that HF in the Karoo Basin has several challenges on several levels. Not all work done to determine if a shale gas industry should be developed in South Africa would be negative or detrimental to the environment and we do have qualified geohydrologists with sufficient experience to assess the risks to shallow groundwater resources. It would also be possible to develop technical regulations and protocols for a fractured system environment. Groundwater is a field of science with numerous sub-divisions, each with its own core scientific base e.g. aquifer mechanics, geochemistry, geophysical surveys and groundwater management. It is therefore important that each of these sub-divisions be appropriately utilised by experienced experts in each category to be able to create a conceptual model that will be able to assist in measuring, calculating and estimating parameters that will influence groundwater flow and quality as well as identify any possible risk from HF on shallow groundwater resources in order to facilitate sound groundwater governance. The possibility of a HF industry should be seen as an opportunity in South Africa to enhance our knowledge on our deep aquifers and to develop analytical methodologies and solutions for such conditions or alternatively determine whether existing analytical approaches are still valid in a deep fracture system environment. As it is expected that numerical modelling would form part of any groundwater investigation, it would then be sensible to ensure that analytical solutions used for data interpretation should be of a standard in order to compile a conceptual model that is simple enough to allow for numerical modelling but as comprehensive and accurate a reflection of the physical environment being investigated as possible. Numerical models can be regarded as a powerful tool in assisting geohydrologists and ultimately regulators in making better and well-informed decisions. There are obvious concerns regarding water governance and specifically groundwater governance in South Africa. Currently the whole concept of governance can be considered as dysfunctional with no real leadership and example at the top echelons of government and regulators. If groundwater governance is not developed in the sense of establishing local and regional monitoring networks and establishing an institutional environment where data and information are verified, validated and interpreted in a timely manner, there should not even be any thought of establishing a HF industry in South Africa. Research has indicated that in all countries where HF has been allowed on large scale, information about frequency and severity record keeping and reporting has been horrendously neglected due to historical regulatory gaps and loopholes, either existing due to a lack of research skills or funding or even created as is evident by the “Haliburton loophole”. The development of a tool to assess and quantify, GroundWater Risk Assessment Tool (GW-RAT), was therefore regarded as an important aspect of this research project. Considerations were to keep it as simple as possible but to highlight specific aspects and/or activities that seems to be essential from a South African perspective. Research for this theoretical analysis of possible impacts associated with HF on Karoo Basin geohydrology yielded various results. In some cases obvious impacts can be minimised by preventative and/or mitigation measures, while some other impacts that are more indirectly involved have been identified as more concerning. From a technical perspective and available knowledge and skills within the South African geohydrological community, it is evident that we would be able to carry out site-specific investigations to generate enough information to conduct a comprehensive risk assessment with a high level of confidence.