A standard methodology for establishing a groundwater baseline for unconventional gas projects in South Africa did not exist at the time the current study was undertaken. The study was therefore aimed at filling this gap, specifically focusing on hydraulic fracturing and underground coal gasification (UCG) operations.
An extensive literature review was conducted to establish the baseline methodology. The latest literature on hydraulic fracturing and UCG was reviewed to determine how these activities may potentially impact on the groundwater environment. The literature review further examined the role that geological structures, such as dolerite intrusives, may be play in the migration of contaminants associated with unconventional gas projects. The literature review then focused on questions such as what size the study area should be, what geological and hydrogeological investigations need to be conducted before embarking on the sampling events, which chemical parameters need to be included in the groundwater analyses, whether the drilling of dedicated boreholes are required to collect representative groundwater samples, and how to collect representative samples for these different chemical parameters.
In this paper, the proposed methodology is presented in the form of a flow diagram to be used to guide future groundwater baseline projects in South Africa.