Conference Abstracts

All Abstracts were presented at the Groundwater Conferences

Displaying 551 - 600 of 795 results

Title	Presenter Name	Presenter Surname Sort descending	Area	Conference year	Keywords
Understanding Groundwater Geochemsitry Of A Plunging Syncline South Of Robertson, Western Cape, South Africa	Neville	Paxton	Robertson, Western Cape, South Africa	2017	Groundwater Geochemistry, Plunging Syncline
Abstract The use of groundwater in the Robertson area, Western Cape, specifically to the south of the town is underdeveloped. The Breede River is the primary source for irrigation of vineyards and livestock watering through various channels and waterways. In an attempt to secure an additional water supply, small scale groundwater exploration was conducted which has culminated into an extensive network of boreholes with varying yields and geochemical signatures. As demand for usable water increases, a better understanding of the quality of the groundwater is as significant as the quantity of groundwater available for informed decision-making. This study area overlies a plunging asymmetrical syncline which comprises of the Rietvlei sandstones of the Table Mountain Group (TMG) and the younger Bokkeveld Group. The TMG forms mountain ranges on the southern and northern limbs of the syncline. Boreholes of higher blow yields were selected to undergo yield tests to determine sustainable yields. Higher yielding boreholes with an average yield of 7.4 L/s were drilled into the highly fractured and quartz-rich sandstones, while lower yielding boreholes with an average yield of 2.2 L/s were drilled into the Bokkeveld Group. The only existing borehole in use, situated on the northern limb of the syncline along the Sewefontein Fault, had a higher yield than neighbouring boreholes and a significantly better groundwater quality, somewhat of an anomaly in this section of the study area. In an attempt to access groundwater from the same formation, additional geophysical exploration, drilling and testing was conducted. The results however indicated low blow yields and poor quality groundwater. AQTESOLV software was used to further characterise and classify aquifer parameters. Descriptive statistics together with graphical hydrological methods were used to characterise the geochemical composition of the groundwater. The lithology of the study area indicates that the syncline has been extensively fractured as a result of post depositional folding and faulting. Fractures with a primary strike direction of 120° to 140° provide flow paths across the different formations, indicated by geological logs and borehole connectivity. Mean transmissivity values for the TMG are almost double that of the Bokkeveld Group, and salinity of the latter is significantly higher than that of the TMG. Transmissivity provides an indication of residence time (with an inverse relation) and thus leads to the assumption that groundwater flow rate is slower in the Bokkeveld Group. Elevation also plays a role, with a negative correlation to salinity. Recharge is delayed in lower lying areas which are predominantly underlain by Bokkeveld Group rocks, and clay rich derivative soils. Water readily ponds here and undergoes increased evapouration. The resultantsalt precipitation gets flushed into the saturated zone during future rainfall events. Recharge that does reach the saturated zone increases in salinity along its flow path due to ion absorption and cation exchange with clay minerals. Higher lying areas have little to no soil cover, with the thin soils comprising almost solely of quartz grains - considered chemically inert. As groundwater flows from the TMG into the Bokkeveld Group, residence time increases and salinity levels increase significantly.
The Economics Of Sustainable Groundwater Ecosystem Services	Darian	Pearce	National	2013	economic value, natural assest values, ecosystem services values
Abstract This paper outlines the core factors related to the economic assessment of groundwater resources. Included in the discussion is a delineation of the factors that determine the economic value of groundwater as well as a thorough description of the range of ecosystem services that are derived from groundwater resources. Several factors affect the economic value of aquifers, but these factors can split into two categories, natural asset values and ecosystem services values. Ecosystem services are the benefits that humans receive from ecosystems, and are officially defined by the Millennium Ecosystems Assessment. Ecosystems produce these ecosystem services on an annual basis, and the value of these services accrue on a country’s national income statement, and should ideally be measured through indicators that relate to Gross Domestic Product (GDP). Aquifer themselves are natural assets. They form part of the ecological infrastructure of a country and the values of these assets theoretically appear on a country’s natural resources balance sheet. The asset value can be determined by calculating the Net Present Value (NPV) of the perpetual stream of aquifer ecosystem services delivered. By understanding the full range of factors that underlie the natural asset values of aquifers, along with their ecosystem service values and the full range of inter-temporal and inter-ecosystem service characteristics, we can begin to adequately assess the economic value of groundwater resources.
Danish Groundwater Management Approaches In A South African Context	P.G.	Pedersen	Denmark	2017	Denmark, South Africa
Abstract The North-European country Denmark is in many ways different from the Republic of South Africa. Similarities also exist, for example the common ownership of underground resources. In Denmark, like in South Africa, groundwater forms a strategic resource for water utilization, and a coherent management approach is needed in both countries in order to secure a sustainable and balanced use, in which the wishes of different stakeholders are optimized. Denmark is solely depending on the use of groundwater for domestic, industrial and agricultural use. Therefore, an effective management scheme and new technologies have been developed in order to make groundwater assessments, delineating groundwater protection zones, water preservation, leakage detection, well field monitoring systems etc. This expertise forms the basis of the bilateral Strategic Water Sector Cooperation Programme (SSC), initiated in 2015. The programme consists of three main tracks, respectively focusing on urban water services and NRW, groundwater management, and water efficiency in industries. In addition to these, two cross-cutting tracks focus on water sector financing and the potential for research and innovation cooperation. The preliminary findings of the programme indicate that some of the Danish management approaches and technologies can be used in South Africa, either adapted or directly. In exchange, the South African experiences, amongst others, in how to handle drought, may be relevant in a future Danish context, where extreme weather situations, induced by climate change, is to be expected.
Geohydrological characterisation of the Citrusdal syncline basin	C.	Peek	Western Cape	2017	Geohydrological
Abstract Agriculture in Citrusdal is dominated by citrus fruit farms with the majority of freely available land been occupied by citrus crops. However, agriculture uses large amounts of water, which is often in short supply. During periods of stress where rainfall is low and surface water sources are not recharged and increase in demand for the citrus crops due to global economy has lead farmers to seek alternative sources of water to augment current sources for irrigation. One source in particular is groundwater. Groundwater has become the primary alternative source of water as building dams is an expensive exercise and has inherent limitations, such as faulty dam walls and inflow streams drying up. The development of groundwater sources is relatively cheaper and can be spatially convenient. The Citrusdal valley is located in the Western Cape province of South Africa, the valley is located between latitudes 18o15’ and 19°10’ and longitudes 32o20’ and 32°52’. It is composed of the Precambrian Table Mountain Group (TMG) consisting of sequences of arenites and subordinate argillites overlain by extensive cover of Tertiary to Quaternary sediments. The Citrusdal valley TMG overlies the basement Malmesbury shales at great depth. The Citrusdal Valley is primarily composed of the Peninsula sandstone, Cedarberg shale Formations and the topmost Nardouw Subgroup sandstone. Groundwater is located within two units within the Citrusdal basin, the Nardouw aquifer and Peninsula aquifer. Groundwater in the basin is constrained by large faults, small-scale fracture networks, lithologies, and topography. This project uses groundwater chemistry, exploration drilling and pumping tests to examine the groundwater system in the region to understand the complex geometric and hydraulic properties of the syncline basin. Understanding the geometric and hydraulic properties plays a significant role in developing agriculture in the region and to help manage the groundwater so that it is sustainable.
Characterisation of submarine groundwater discharge into False Bay (Western Cape)	Eric	Petermann	Western Cape	2015
Abstract In this paper we present results of a field study that focused on the characterisation of submarine groundwater discharge (SGD) into False Bay (Western Cape) with emphasis on its localisation. SGD is defined here as any flow of water from the seabed to the ocean. Thus, it includes (1) advective flow of fresh terrestrial groundwater as well as (2) seawater that is re-circulated across the ocean / sediment interface. Groundwater discharge into the coastal sea is of general interest for two reasons: (i) it is a potential pathway of contaminant and nutrient flux into the ocean, and (ii) it may result in the "loss" of significant volumes of freshwater. In our investigation we applied environmental aquatic tracers, namely radionuclides of radon (222-Rn) and radium (223-Ra, 224-Ra), as well as physical water parameters (salinity and temperature). The concentrations of radon and radium can be used as tracers for groundwater discharge since radon and radium are highly enriched in groundwater relative to seawater. We conducted discrete point measurements of seawater and of terrestrial groundwater as well as continuous radon time-series measurements of near-coastal seawater. A large-scale survey was performed along the entire shoreline of False Bay and revealed distinct positive anomalies of radon in the area of Strand/Gordons Bay and a rather diffuse anomaly along the Cape Flats, which is indicating possible groundwater discharge in these areas. The location of these anomalies remained constant to a large extent throughout several surveys that were performed during different seasons, although these anomalies varied with regard to their magnitude and clearness. Further detailed studies were undertaken in the area of Strand/Gordons Bay including radon time-series measurements in the coastal sea at a fixed location in order to estimate the quantity of SGD and its variability on a tidal time scale. The results indicate that groundwater discharge rates are significantly elevated during low tide. Furthermore, the distribution of radium isotopes (224-Ra/223-Ra ratios) in the Strand/Gordons Bay area indicate a "groundwater" residence time of less than 10 days within a distance of 5 km from the shore. In summary, we found spatially considerable constant SGD locations during different field campaigns. Additionally, we gained a rough understanding of the SGD dynamics on a tidal time scale, its magnitude and groundwater residence time within the inner bay after discharge. These results can be beneficial to trace back contamination in near-coastal waters or to find potential locations for groundwater abstraction.
Application of Environmental Tracers for Differentiation of Fresh and Re-Circulated Submarine Groundwater Discharge (Sgd) Into Knysna Estuary, South Africa	E.	Petermann	Knysna Estuary, South Africa	2017	Environmental tracers, Submarine Groundwater Discharge
Abstract In coastal areas worldwide terrestrial groundwater resources and the coastal sea are generally hydraulically connected thus allowing continuous groundwater/seawater interaction. This major form of land-ocean interplay is associated with two potential pathways of dissolved matter transport, namely (1) flux from the marine to the terrestrial environment in form of seawater intrusion into terrestrial aquifers and (2) flux of terrestrial groundwater into the coastal ocean manifested as submarine groundwater discharge (“SGD”). The sea-to-land pathway is of relevance due to the risk of irreversible salinization of coastal groundwater resources and is in most cases a manmade (and hence manageable) phenomenon set off by excessive groundwater exploitation that is not balanced by groundwater recharge. The land-to-sea pathway (i.e. SGD), on the other hand, occurs naturally everywhere an aquifer with a positive hydraulic head is connected to the ocean. It is of interest due to two potential threats, namely (i) the loss of freshwater to the ocean, an issue that is particularly relevant in climate zones characterized by water scarcity, and (ii) the detrimental impact of nutrient- or contaminant-laden groundwater discharge on the coastal water quality, an aspect that is of relevance along urbanized coastlines worldwide. The latter implies that SGD localization and quantification is of major relevance with regard to (i) the evaluation of the vulnerability of the coastal sea to groundwater pollution and for (ii) understanding the associated matter cycles including nutrients, organic compounds or inorganic contaminants. We present results of an environmental tracer based approach that aimed at evaluating short-term SGD dynamics into the Knysna estuary, South Africa. Both natural components of SGD, terrestrial freshwater (FSGD) and recirculated seawater (RSGD), were estimated individually. We conducted an end-member mixing analysis for time series of radon (222Rn) and salinity over two tidal cycles in order to determine four water fractions within the estuary: seawater, river water, FSGD and RSGD. The results were backed by stable isotope data (18OH2O and 2HH2O). End-member mixing ratio analyses revealed the mixing ratios that fit best to the observations at every time-step of the 24 h time series, which was carried out near the estuary mouth. Results indicated highest FSGD and RSGD fractions in the estuary water during low tide amounting to 0.2 % and 0.8 % for FSGD and RSGD, respectively. A radon mass balance for the whole estuary revealed a radon flux via SGD of 41 ± 7 Bq m^-2 d^-1, which equals a total FSGD of 4.6 10⁴ m³ d^-1 and RSGD of 1.5 10⁵ m³d^-1 . The results do imply that the majority of nutrient fluxes (DIN) into the estuary are SGD-derived.
Characterisation Of A Large Light Non-Aqueous Phase Liquid (Lnapl) Plume Over A Fractured Gneiss Aquifer In Limpopo Province, South Africa; With Reference To An Ongoing Pump-And- Treat Remediation Technology	Mahlogonolo	Phahlamohlaka	Limpopo	2013	LNAPLS
Abstract Work is being conducted in Limpopo province following a large volume release of petroleum hydrocarbons that took place from a leaking underground pipeline, resulting in significant groundwater contamination. This is considered to be the largest petroleum hydrocarbon release recorded to date in South Africa. The leak took place for 15 years before it was discovered 13 years ago in 2000. From the pressure tests that were performed, 10-15 ML of A-1 Jet fuel is considered to have been released to the subsurface. Product bailing was the first method employed for the recovery of the free product, and was later replaced with a P&T system which was considered to be more effective. The village located about 6 km to the north of the spillage depends mostly on groundwater. This paper presents a progress update of works that have been conducted in support of developing a conceptual model which aims to determine the areal extent of the plume.
Characterisation Of A Large Light Non-Aqueous Phase Liquid (Lnapl) Plume Over A Fractured Gneiss Aquifer In Limpopo Province, South Africa; With Reference To An Ongoing Pump-And- Treat Remediation Technology	M	Phahlamohlaka	Limpopo	2013	plumes, remediation
Abstract Work is being conducted in Limpopo province following a large volume release of petroleum hydrocarbons that took place from a leaking underground pipeline, resulting in significant groundwater contamination. This is considered to be the largest petroleum hydrocarbon release recorded to date in South Africa. The leak took place for 15 years before it was discovered 13 years ago in 2000. From the pressure tests that were performed, 10-15 ML of A-1 Jet fuel is considered to have been released to the subsurface. Product bailing was the first method employed for the recovery of the free product, and was later replaced with a P&T system which was considered to be more effective. The village located about 6 km to the north of the spillage depends mostly on groundwater. This paper presents a progress update of works that have been conducted in support of developing a conceptual model which aims to determine the areal extent of the plume.
Characterisation of a large LNAPL plume in Limpopo Province, South Africa	Mahlogonolo	Phahlamohlaka	Limpopo	2015
Abstract Work is being conducted in Limpopo province following a large volume spill of petroleum hydrocarbons that took place from a leaking underground pipeline, resulting in significant volume of groundwater contamination. This is by far the largest spillage to date in South Africa.10 million litres of jet fuel leaked for a 15 year period from an underground pipeline until its detection 13 years ago. The leak has since been repaired and bailing was the first method proposed and applied to the recovery of the free product, but due to its ineffectiveness the "quicker"pump-and-treat method replaced it. Due to complications caused by pum-and-treat, the process was stopped in 2007 and is about to be reinstated again in 2013. A village to the north of the spillage depends mostly on groundwater. Immediate remediation actions have to be established before the contaminant reaches their abstraction boreholes. This project aims to model the areal extent of this contaminant and eventually design a life cycle of remediation. This will be based on comparison between existing models dated 2002 and 2012 respectively for background information and to address the influence of ten years' bailing, pumping and natural attenuation. The new model will focus around implementing remedial measures to prevent further migration of the free phase or dissolved plumes in order to protect the water supply to the surrounding villages. The progress will be presented in this paper.
Investigating Methods to Identify Groundwater Dependent Ecosystems and Assess Potential Impacts of Shale Gas Developments in the South Western Karoo, South Africa	Louelle Chelsea	Philander	Western Karoo, South Africa	2017	Dependent Ecosystems, Shale Gas Developments
Abstract The need to diversify energy resources for South Africa has brought developing shale gas to the forefront. Consequently, the semi-desert Karoo basin in South Africa is being explored as a potential source for shale gas resources. South Africa’s limited water resources have caused concern because groundwater resources are the main source of water for irrigation, drinking and for sustaining groundwater dependent ecosystems. Groundwater dependent ecosystems are found across the South African landscape, affecting the environment and ecological processes where groundwater flow to and discharge from aquifers. The current study assesses potential impacts of shale gas developments on groundwater dependent ecosystems in the Karoo area. Groundwater dependent ecosystems were identified and categorized based on a combination of hydrogeological and morphological type setting. Direct methods based on terrestrial setting and indirect methods based on hydrogeochemistry for determining interaction between groundwater and the groundwater dependent ecosystem were assessed. Preliminary results lean towards potential risks to groundwater dependent ecosystems and shallow aquifer systems from surface processes during shale gas developments instead of subsurface processes. Therefore, it is suggested to ecologically assess groundwater dependent ecosystems and further study the influence of shale gas development on groundwater dependent ecosystems at regional scale perspective in South Africa to inform a level of protection and risk management.
Water Monitoring in the Mining Industry: An Overview	Callie	Pickering		2015
Abstract Water monitoring is a key aspect in the mining industry, in terms of gathering baseline data during the pre-construction stage, identifying potential areas of concern and mitigating source pollutants during the operational stage. A proper water monitoring program assists in the monitoring of plume development and water level rebound during the closure phase. The data made available through consistent long term monitoring should not be underestimated. Monitoring the effect that coal mine operations have on the water quality and quantity of surface and groundwater resources is a complex and multidisciplinary task. Numerous methodologies exist for monitoring of this kind. This paper will supply an overview of the water- rock chemistry associated with coal mine environments and the key indicator elements that should be focused on for water monitoring as well a review of the Best Practice Guidelines requirements in terms of water monitoring. Two case studies of coal mines in KwaZulu Natal will be reviewed, the key challenges outlined and mitigation measures implemented. The impact of requirements such as those set out by the Department of Water and Sanitation in terms of strict water quality limits for water containment and waste facilities as specified by Water Use Licences has also created unrealistic non-compliance conditions. The initial approach to creating a water monitoring programme should involve first identifying gaps in previous datasets and delineating potential sources of contamination. The sampling frequency will depend primarily on the water resource being monitored and the water quality analysis will depend on the type of facility. The facilities required for a specific situation will depend on the type and amount of waste generated, potential for leachate formation, vulnerability of groundwater resources and potential for water usage or resource sensitivity.
Characterization of groundwater dynamics to identify the risks of flooding of the sewerage network of the urban communities of Lens-Liévin (northern France)	G	Picot-Colbeaux	France	2023	aquifer, Groundwater, groundwater inflow, hydrodynamic modelling, piezometry, sewerage network, urban hydrogeology
Abstract The interactions between groundwater and the sewerage networks of the Lens-Liévin urban communities, located in the north of France, locally lead to non-compliance in the operation of the network and the wastewater treatment plants, questioning the city’s economic development policy. Indeed, the infiltration of groundwater inflow in the sewerage network could be the cause. Based on the piezometric measurements carried out in 2022, the surface elevation of the groundwater table is carried out using a kriging approach. The comparison of altitudes between network position and piezometry made it possible to identify the pipes most at risk of the infiltration of groundwater inflow and correspond to those indicated as non-compliant by network managers according to the national decree. Outside this period, the network vulnerability indicators are defined based on simulated piezometry by a 3D hydrodynamic model of the chalky hydrosystem (MARTHE code) established in a transient state. For two past extreme situations, the network would have been flooded at 1.20% in the dry period (1997) and up to 8.30% in the wet period (2001), highlighting the existence of a part of the network systematically flooded. Using the hydrodynamic model according to different prospective scenarios makes it possible to anticipate the actions deployed on the network to guide management and adaptation solutions. However, a modelling methodology that considers the feedback between the dynamics of the groundwater and the flows passing through the networks remains to be developed.
The Use Of Vegetable Oil Substrates In The Treatment Of Contaminated Groundwater	M	Pienaar	National	2013	prevention strategies, contamination, Water treatment
Abstract Edible vegetable oil (EVO) substrates have been successfully used to stimulate the in situ anaerobic biodegradation of groundwater contaminated with chlorinated solvents, as well as numerous other anaerobically biodegradable contaminants like nitrates and perchlorates at many commercial, industrial and military sites throughout the world. EVO substrates are classified as a slow release fluid substrate, and comprise of food-grade vegetable oil such as canola or soya bean oil. The EVO substrate serves as an easily biodegradable source of carbon (energy) used to create a geochemically favourable environment for the anaerobic microbial communities to degrade specific contaminants of concern. EVO substrate’s can either be introduced into the subsurface environment as pure oil, in the form of light non-aqueous phase or as an oil/water emulsion. The emulsified vegetable oil substrates has several benefits over non-emulsified vegetable oil as the fine oil droplet size of the commercially manufactured emulsified oils can more easily penetrate the heterogeneous pore and fracture spaces of the aquifer matrix. The use of this technology to stimulate in situ biodegradation of groundwater contaminants is still relatively unknown in South Africa. This paper gives an overview of the EVO technology and its application, specifically looking at the advantages of using this relatively inexpensive, environmentally-friendly based technology to remediate contaminated groundwater within fractured rock environments commonly encountered in South Africa.
The use Vegetable Oil Substrate's in the treatment of contaminated groundwater	Michelle	Pienaar		2015
Abstract Edible vegetable oil (EVO) substrates have been successfully used to stimulate the in situ anaerobic biodegradation of groundwater contaminated chlorinated solvents as well as numerous other anaerobically biodegradable contaminants like nitrates and perchlorates at a many commercial, industrial and military sites throughout the United States of America and Europe. EVO substrates are classified as a slow release fluid substrate, and comprise of food grade vegetable oil such as canola or soya bean oil. The EVO substrate serves as an easily biodegradable source of carbon (energy) used to create a geochemically favorable environment for the anaerobic microbial communities to degrade specific contaminants of concern. EVO substrate's can either be introduced into the subsurface environment as pure oil, in the form of light non aqueous phase or as an oil/water emulsion. The emulsified vegetable oil substrates holds several benefits over non-emulsified vegetable oil as the fine oil droplet size of the commercially manufactured emulsified oils can more easily penetrate the heterogeneous pore and fracture spaces of the aquifer matrix. The use of this technology to stimulate in situ biodegradation of groundwater contaminants is still relatively unknown in South Africa. This paper will give an overview of the EVO technology and its application, specifically looking at the advantages of using this relatively inexpensive, innocuous substrate based technology to remediate contaminated groundwater within fractured rock environments commonly encountered in South Africa. {List only- not presented}
Developing The South African National Groundwater Monitoring Network	Kevin C	Pietersen	National	2017	monitoring network
Abstract The Department of Water and Sanitation reviewed and re-designed (optimised) the national water resources monitoring networks. During the re-design, monitoring objectives were formulated and prioritised. The highest priority, i.e. to make available data and information related to quantity and quality of present and future water resources is through planned infrastructure development and other interventions. The data and information dissemination aims at providing strategic decision support for the equitable and sustainable allocation of resources to the population, environment and other economic sectors of society. In setting up the groundwater monitoring network, an approach was followed which allowed for the incorporation of local and international best-practice; hydrogeological information combined with expert knowledge. We used the following criteria to establish the baseline or background sites for the national groundwater monitoring network: borehole spatial densities; pristine areas (no land-use activities); aquifer yield; recharge; baseflow; sites for background monitoring related to groundwater reserve determinations and the setting of resource quality objectives; springs; and international obligations. Trend monitoring sites were selected around baseline sites and around towns who were groundwater dependent. The trend monitoring sites allow for trends to be determined in terms of: (i) over-exploitation/abstraction of groundwater; (ii) groundwater quality degradation from various land use practices; and (iii) groundwater water use. Regional Spatial Design Workshops were held to compare the existing water resources monitoring network with the newly designed network and the existing monitoring network were optimised accordingly. Google Earth was used to query the detail of the monitoring sites, consider land-use coverages and incorporated expert input to position sampling points in line with the monitoring objectives. The implementation of the updated groundwater monitoring network will rely predominantly on hydrogeological considerations and field- based investigations and observations. When the networks are optimised, statistical techniques will be useful to ascertain monitoring point location, redundancy and frequency.
Understanding informal institutions’ role in groundwater management – Lessons from borderland communities	Kevin	Pietersen	Africa	2023	groundwater governance, informal institutions, transboundary aquifers
Abstract Across Africa, given the pressing challenges of climate change and widespread water, food and livelihood insecurity and poverty, there is an ever-increasing expanding role for groundwater in resilience building, especially in borderland communities. This situation is being investigated in several projects and geographies. This paper’s groundwater management analysis was based on literature reviews, key informant interviews (KIIs), and focus group discussions (FGDs) in selected case study areas throughout sub-Saharan Africa. The KIIs included representatives of water management institutions, community leaders, international development partners, the private sector and non-governmental organisations (NGOs) involved in the use or management of groundwater. The FGDs occurred in borderland communities in Ethiopia, Kenya, and Somalia (with these three countries sharing borders) and Mozambique, South Africa and Zimbabwe (with these three also sharing borders). The findings show that informal institutions such as clan, tribal or ethnic affiliations dictate access to natural resources such as groundwater in borderlands. These same Institutions also play a significant role in conflict resolution in the borderland areas. In addition, informal institutions play an essential role in groundwater management and should also be recognised – in engagements and formal water policies and legislation. Formal organisations, institutions and government structures should strengthen their focus on ensuring that discussions and decisions include informal role players. Further developing and enforcing conventions, land-use plans, and bylaws governing access to and use of groundwater should ensure engagement and co-creation of solutions towards effective water resource management.
Baseflow as a Proxy for Groundwater Recharge Variation Following Environmental Disturbances, Jonkershoek Valley, Western Cape, South Africa	Raven J	Pietersen	Jonkershoek Valley, Western Cape, South Africa	2017	Environmental Disturbances, groundwater recharge
Abstract Groundwater recharge is of strategic importance in groundwater research both globally and locally in South Africa as it ensures that the development of groundwater does not exceed the systems rate of renewal, protecting the integrity of these resources. The Table Mountain Group (TMG) system is considered to a potential source of future bulk water supply with a recharge potential ranging from 7 to 23% of Mean Annual Precipitation (MAP). However, estimation of true groundwater recharge is challenging as groundwater recharge is affected by many factors which influence the ability of water to reach the water table. Various studies have been carried out within the Jonkershoek Nature Reserve which investigated the response of a catchment’s hydrological functioning and biodiversity to land use management and disturbance regimes such as fires. Previous studies assessed the effect of fire on the hydrology of the catchment, highlighting the associated increase in streamflow components and hydrological response of catchments due to the development of soil water repellency which generated rapid runoff but do not discuss the possible effects on the recharge potential to the groundwater system. The present study investigated the possible effects of wildfire disturbances on local groundwater recharge system of the TMG aquifer system in Jonkershoek Valley, Western Cape Province of South Africa using baseflow as a proxy for groundwater recharge. The possible effects of wildfire disturbance on groundwater recharge processes were determined through review of literature, lithological logs and geological maps. Baseflow separation of hydrographs was conducted using the Recursive Digital Filter Method. It was found that the baseflow response to rainfall events following the March 2015 fire remained unchanged for the Tierkloof sub-catchment of Jonkershoek whereas Langrivier experienced a decline in baseflow response following the winter rainfall period later that 2015. The findings suggest that wildfire to some extent influences groundwater recharge but not all times thereby providing insight on the extent of influence of a vegetation cover on groundwater recharge and confirming findings from previous studies. The present study recommends long term studies on the influence of wildfire on groundwater recharge and the use of both direct and indirect methods for investigating groundwater response to fires.
The Role Of Brackish Groundwater In Water Security	Kevin C	Pietersen	South Africa, USA	2019	brackish water, groundwater management, Licence conditions
Abstract Brackish groundwater resources could become an option to diversify the water supply-mix in the future when coupled with desalination or other evolving and cost effective water treatment technologies. This paper discusses regulatory and management responses dealing with brackish groundwater in international jurisdictions to form a basis for decision-making in groundwater management in South Africa. Recent literature and research on brackish groundwater was reviewed to reflect on efforts by other jurisdictions (California, Texas - USA) to regulate and manage brackish groundwater and to formulate desirable goals for brackish groundwater management for South Africa. The regulatory responses in international jurisdictions include pollution prevention, permitting, underground disposal control and differentiated groundwater use. The groundwater management responses include adaptive management, optimized groundwater abstraction, demand management approaches, managed aquifer recharge and alternative technologies. Based on the review the following strategic objectives are defined for South Africa: (i) implement responsible brackish groundwater use in areas with low salinity groundwater; (ii) promote brackish groundwater supplies for desalination; (iii) establish rules for the protection of brackish aquifers from activities in the subsurface; and (iv) create regulatory certainty about the use of brackish groundwater resources. There are several beneficial uses of brackish groundwater resources. In the USA and Canada, brackish groundwater is now the norm in unconventional gas development whereas in water-scarce areas, drinking water is being produced by desalination of brackish groundwater. In Texas - USA, municipalities choose to pay for the cost of advanced treatment rather than incur the cost of building additional water transportation infrastructure (dams, canals, and pipelines) or securing additional water rights. Some industries may use brackish groundwater with minimum or no treatment. Untreated, low-salinity brackish water may be used for irrigation, and higher-salinity waters may be used for the cooling of power plants. Groundwater is a public good in South Africa which requires an authorization for its sustainable abstraction, and It is therefore important to stipulate the correct licence conditions for sustainable brackish groundwater. Critical are the conditions for discharging brine concentrate resulting from desalination processes. It is unlikely that apart from the coastal areas, there may be deep saline aquifers to dispose the brine and these areas require detailed hydrogeological studies - this knowledge is currently not available.
Groundwater Governance Requirements for the Exploration and Production of Unconventional Gas Sources	Kevin C	Pietersen	Karoo	2013	groundwater governance
Abstract South Africa has an energy crisis. The country requires 53 Gigawatt of new capacity by 2030. The exploitation of unconventional gas is a potential game-changer to meet South Africa’s current energy deficit to fuel economic growth and development. Water management, both in terms of abstraction and disposal, has emerged as a critical issue in the development of unconventional gas reservoirs. This presentation focuses on a high-level, qualitative analysis of the groundwater-related institutional and governance challenges associated with unconventional gas exploration and production. The findings represent a synthesis of information sourced from regulatory and legislative documents as well as international experience. The analysis maps the current groundwater institutional and governance landscape in South Africa and lessons learned from other regimes such as the United Kingdom and United States of America. Good governance entails ensuring that there is compliance with policy and legislation, effective decision-making, appropriately allocated accountability, transparency and that stakeholder interests are considered and balanced. This forms the basis of a preliminary gap analysis.
An Analysis Of The Challenges For Groundwater Governance During Unconventional Gas Development In South Africa	Kevin C	Pietersen	National	2015	groundwater governance, Unconventional gas
Abstract The groundwater governance arrangements for the development of groundwater resources were analysed. The analysis highlighted gaps and barriers to overcome before unconventional gas (shale gas and coal bed methane) development can take place at an industrial scale. The following governance challenges were identified (i) setting baseline measurements to detect groundwater pollution and to determine resource status; (ii) review of licenses and setting conditions for the development of unconventional resources; (iii) compliance monitoring and enforcement systems in place (iv) dealing punitively with non-compliant operators (v) mitigation options in place to prevent groundwater pollution; (vi) goal-based regulatory framework in place rather than a prescriptive regulatory framework; (vii) disclosure of hydraulic injection fluid; (viii) coordination with other government departments and regulatory bodies; (ix) a framework for subsidiarity and support to local water management; and (x) an incentive framework that support good groundwater management. To overcome the challenges requires a decentralized, polycentric, bottom-up approach, involving multiple institutions to deal with unconventional gas development. This provides better conditions both for cooperation to thrive and for ensuring the maintenance of such institutions.
Expanding the boundaries of the Eastern Kalahari Karoo Transboundary Aquifer (EKK-TBA) shared between Botswana and Zambia: A governance challenge	Kevin C	Pietersen	Karoo, Botswana, Zambia	2021	transboundary, joint management
Abstract The EKK-TBA is significant in anchoring Gross Domestic Product growth and development in both countries is heavily reliant on groundwater. Recently a transboundary diagnostic analysis (TDA) and a strategic action plan (SAP) for the EKK-TBA was completed. The analysis resulted in a three-fold expansion of the EKK-TBA boundary. The new EKK-TBA boundary overlaps part of the Okavango and Zambezi River Basins and now also includes major wellfields in Botswana and Zimbabwe (Nyamandlovu and Epping Forest) as well as the Makgadikgadi Pans which act as the surface water and groundwater discharge zone. An analysis of institutional arrangements was carried out to enhance effective and efficient management of the EKK-TBA. Noting the complexity of the EKK-TBA. the initial institutional response could potentially be the development of a bilateral agreement between Botswana and Zimbabwe for cooperation and coordination to support the management of the TBA. This agreement would seek to establish a Joint Permanent Technical Committee (JPTC) that would also co-opt in members from the two shared watercourse commissions. Such a JPTC would enable improved coordination across the varying transboundary dimensions and would align with the precepts of the Revised Protocol on Shared Watercourses. This would include such principles including sustainable utilization, equitable and reasonable utilisation and participation, prevention, and co-operation, as well as aspects of data and information exchange and prior notification.
Effectiveness of Groundwater Governance in the Southern African Development Community (SADC) Countries	Kevin C	Pietersen	SADC	2017	Southern Africa Development Community
Abstract Water security is pivotal for economic growth, sustainable development and poverty reduction in SADC. Increasing aridity and dwindling surface water supplies are resulting in new opportunities for groundwater as a source for domestic, agricultural and industrial use. We carried out an assessment of groundwater governance in the SADC region to determine the effectiveness of provisions to regulate groundwater. Numerous sources of information were solicited, reviewed, and data was mined using framework analysis and qualitative context analysis approaches. This provided a systematic model for managing and mapping the data. There is a good understanding of aquifer systems at the regional level. Transboundary aquifers have been delineated and areas prone to groundwater drought have been identified. Information systems to manage groundwater data, however, are disparate throughout the region and institutions to manage groundwater are inadequate and are functioning within an environment of scarce financial and human resources. The hydrogeological capacity in public institutions such as government departments is a major concern and regulations to protect groundwater resources are often not in place. This includes instruments to control groundwater abstraction and potentially polluting activities. Where regulatory instruments are in place, often no enforcement or sanctions of unlawful activities are taking place. There is also limited coordination with other sectors such as energy and mining. Furthermore, the implementation of groundwater management action plans, where developed, is weak. Overall, groundwater management in the SADC region was found to be poor. Whilst the groundwater governance challenges are great, there are opportunities to support diagnostic analysis of transboundary aquifer systems, competency development, establishing regional groundwater monitoring networks, strengthening institutional frameworks, and development of groundwater resources, e.g. to clear the backlog in access to improved water supply.
Assessing aquifer vulnerability using tritium and machine learning in Africa’s western Sahel	Joel	Podgorski	Switzerland	2023	Groundwater, groundwater mapping, groundwater recharge, Groundwater Vulnerability, Isotopes, Machine learning, Tritium
Abstract Understanding the sensitivity of groundwater resources to surface pollution and changing climatic conditions is essential to ensure its quality and sustainable use. However, it can be difficult to predict the vulnerability of groundwater where no contamination has taken place or where data are limited. This is particularly true in the western Sahel of Africa, which has a rapidly growing population and increasing water demands. To investigate aquifer vulnerability in the Sahel, we have used over 1200 measurements of tritium (3H) in groundwater with random forest modelling to create an aquifer vulnerability map of the region. In addition, more detailed vulnerability maps were made separately of the areas around Senegal (low vulnerability), Burkina Faso (high vulnerability) and Lake Chad (mixed vulnerability). Model results indicate that areas with greater aridity, precipitation seasonality, permeability, and a deeper water table are generally less vulnerable to surface pollution or near-term climate change. Although well depth could not be used to create an aquifer vulnerability map due to being point data, its inclusion improves model performance only slightly as the influence of water table depth appears to be captured by the other spatially continuous variables.
Hydrocarbon Remediation – Practical Low Cost And Low Maintenance Solutions	Jennifer A	Pretorius	National	2013	Hydrocarbon, contamination
Abstract In recent years there is an increased awareness of hydrocarbon contamination in South Africa, and the need for remediating sites affected by these contaminants. Hydrocarbon contamination of groundwater can be caused by a large variety of activities at industrial, mining or residential areas. Once these contaminants are discovered in groundwater where it poses risks to human health and/or the environment, remediation is often required. Remediation of groundwater has become a booming industry for groundwater practitioners and often there is an attitude of more sophisticated and expensive solutions are better. This paper will show that this attitude is not always the best solution, but rather recommend an approach where a combination of low cost/low maintenance system need to be investigated and applied to reach clean-up goals. Determination of natural attenuation potential and on-going monitoring forms an integral part of this type of solution.
Modelling Of Impacts Of Fracking On The Karoo Groundwater Systems	Jennifer-lee	Pretorius	The Karoo	2013	Fracking
Abstract POSTER Hydraulic fracturing, also known as hydrofracking or fracking, is being engaged in the Karoo region of South Africa in order to enhance energy supplies and improve the economic sector. It will also lead to independence in terms of reduced amount of imports for fuel due to an estimated 13.7 trillion cubic metres of technically recoverable shale-gas reserves in South Africa. Fracking is an extraction technique used with the purpose of having access to alternative natural methane gas, which is interbedded in shale deposits deep under the surface of the earth. In this process boreholes are drilled horizontally into shale formations to cover a larger area in the shale and subsequently attain more natural gas. After these horizontal boreholes are drilled, large volumes of water, mixed with chemicals and sand, are pumped into these boreholes under a very high pressure, forcing the natural gas out. This water mixture is referred to as the fracking fluid. Water is the main component in the fracking fluid and the water used for the fluid reaches volumes up to 30 million litres per borehole. The aim of this study is to present a baseline study of the area and its water resources to ultimately facilitate in resolving the actual impact hydraulic fracturing will have in the area, using a simulation model which will predict the migration of the fracking fluid in the subsurface. In this model, the chemistry of the fracking fluid will be included to determine the impact it might have on the groundwater quality in the area
Groundwater Inflow Investigation At Finsch Diamond Mine	Adriaan	Pretorius	Finsch Diamond Mine	2019	Poster, inflow, mining
Abstract Historically Finsch Diamond Mine has experienced groundwater inflow in the underground workings of the mine. The inflow results in unsafe and undesirable working conditions. Sampling was conducted over a three month period in order to determine the source of the groundwater inflow. The sampling consisted of various underground samples, monitoring borehole samples as well as surficial water body samples. The samples were analysed for major and minor chemical constituents as well as O18 and H2 isotopes. In order to determine the source of inflow in the underground workings the samples were compared to that of the South African drinking water standard (SANS), graphically interpreted via Piper, expanded Durov and Stiff Diagrams as well as isotopically analysed by comparison to the Global Meteoric Water Line (GMWL). Geochemical modelling was employed in order to determine the typical chemical constituents where groundwater interacts with tailings material and to calculate mixing ratios. Comparison to SANS and the geochemical modelling indicated that elevated sulphate and sodium is associated with fine residue deposit (FRD) water. The Piper and expanded Durov diagrams indicated the presence of three major water types namely: calcium-magnesium-bicarbonate, calcium-magnesium-sulphate and sodium-sulphate types. The isotope analysis indicated the presence of three major water types namely: samples which correspond well with the GMWL, samples which do not correspond well with the GMWL but fall along a mixing line and water which does not correspond with the GMWL. From the analyses, it was clear that water with a sodium-sulphate signature and an evaporated nature, as seen from the isotope data occurred in the underground workings of the mine. These samples corresponded well with water from a nearby FRD and indicate that the FRD is responsible for inflow on shallow levels of the mine.
Groundwater models for water resources assessment at regional, local and site scales	V	Price	England	2023	England, Groundwater/surface-water relations, numerical modelling, scale, water-resources Management
Abstract For 25 years, the UK’s Environment Agency has commissioned groundwater flow models of the main aquifers in England. These regional-scale models are regularly updated, occasionally recalibrated and used for water resources management, regulatory decisions and impact assessment of groundwater abstractions. This range of uses requires consideration of the appropriate scale of data collection and modelling and adaptation of the groundwater models, with refinement where local impacts on individual springs and seasonal streams are considered and combination and simplification for strategic national water resources planning. The Cretaceous Chalk, a soft white limestone, is the major aquifer of southern and eastern England, supplying up to 80% of the drinking water in this densely populated region. Springs and baseflow of good quality groundwater feed Chalk streams, which are a rare and valuable habitat with a high public profile, but face significant challenges in the 21st century, worsened by climate change and population growth. The modelling informs strategic planning and regulatory decisions, but the model’s scale needs to be appropriate for each issue. The presentation defines these issues and presents examples, ranging from the large-scale, strategic Water Resources East to impact assessment for individual groundwater abstractions and more bespoke local investigations, including simulation of groundwater flood risks. As the scale of investigations reduces, there is increasing importance on the accuracy of information, both temporally and spatially. Model refinement made during local investigations can be incorporated into larger-scale models to ensure that this understanding is captured.
Effects Of Dolerite Intrusions On The Geohydrology Of Upper Karoo Sediments In The Elundini Area, South Africa	J	Prinsloo	The Elundini Area, South Africa	2013	Dolerite Intrusions, Geohydrology, Groundwater
Abstract The Karoo Supergroup has a hydrogeological regime which is largely controlled by Jurassic dolerite dyke and sill complexes. The study area is located in the north-eastern interior of the Eastern Cape Province, close to the Lesotho border. The sedimentary rocks of the upper Karoo constitute fractured and intergranular aquifers, due to relatively hydro-conductive lithologies. The main groundwater production targets within the upper-Karoo are related to dolerite intrusions that have a number of characteristics that influence groundwater storage and dynamics. Magnetic, electromagnetic and electrical resistivity geophysical techniques are used to determine the different physical characteristics of the dolerite intrusions, such as size, orientation and the level of weathering. Trends in the data collected from a large-scale development programme can provide evidence that intrusion characteristics also play a role in determining the hydrogeological characteristics of the area. Interpreted geophysical borehole drilling, aquifer testing and water chemistry data can be used to indicate hydrogeological differences between dolerite intrusion types. Observed trends could be used for more accurate future well-field target areas and development.
Effects Of Dolerite Intrusions On The Geohydrology Of Upper Karoo Sediments In The Elundini Area, South Africa	Jakobus	Prinsloo	The Elundini Area, South Africa	2013	Geohydrology
Abstract The Karoo Supergroup has a hydrogeological regime which is largely controlled by Jurassic dolerite dyke and sill complexes. The study area is located in the north-eastern interior of the Eastern Cape Province, close to the Lesotho border. The sedimentary rocks of the upper Karoo constitute fractured and intergranular aquifers, due to relatively hydro-conductive lithologies. The main groundwater production targets within the upper-Karoo are related to dolerite intrusions that have a number of characteristics that influence groundwater storage and dynamics. Magnetic, electromagnetic and electrical resistivity geophysical techniques are used to determine the different physical characteristics of the dolerite intrusions, such as size, orientation and the level of weathering. Trends in the data collected from a large-scale development programme can provide evidence that intrusion characteristics also play a role in determining the hydrogeological characteristics of the area. Interpreted geophysical borehole drilling, aquifer testing and water chemistry data can be used to indicate hydrogeological differences between dolerite intrusion types. Observed trends could be used for more accurate future well-field target areas and development.
Development and calibration of tools for preliminary quantification of the Hydrogeological Interference Risk of tunnels in different geological settings	E	Pugliese	Italy, Switzerland	2023	Hydrogeological Risk, potential inflow, tunnel, Machine learning
Abstract Predicting and quantifying the hydrogeological interference of big underground works is a complex effort. This is due to the considerable uncertainty in estimating the key geomechanical and hydrogeological parameters affecting the area of potential interference of the projects. Moreover, the pattern of involved groundwater flow systems is hardly identified, either in natural or disturbed conditions. Base tunnels through mountain ridges are particularly complex in their interactions with groundwater. Several approaches and tools have been published to predict the magnitude and distribution of water inflows inside tunnels and their impact on many receptors (springs, rivers, lakes, wells, groundwater-dependent ecosystems). The research, co-funded by Italferr Spa (Italian railway national company for tunnel design), deals with calibrating and validating these methods based on huge datasets. Main engineering companies provided data from completed base tunnel projects. In particular, in this study, the Drawdown Hazard Index (DHI) method has been calibrated with a dataset of a 15 km long sector of the Gotthard base tunnel drilled through a crystalline geological setting. The calibration involved only the Potential Inflow (PI) parameter to verify the matching between the probability of inflow and the actual output of the excavation, according to the available data in the preliminary stage of the project. An alternative tool based on a machine-learning approach was then applied to the same dataset, and a comparison was presented.
Sustainable rehabilitation of production boreholes: Application of ph-neutral iron(III)dissolvers by closed-circuit injection	Päivi	Puronpää-Schäfer	Finland, Germany, others	2021	Rehabilitation, maintenance, closed-cicuit injection
Abstract Clogging of existing boreholes due to natural well ageing is the most common cause of decreasing yield worldwide, also in South Africa. Maintenance plans based on systematic monitoring are required including inspection, service and rehabilitation to lengthen production times and to slow down ageing processes. Therefore a prerequisite of economical well operation is to apply the most efficient measures to secure their production capacity at the lowest possible cost. Rehabilitations by mechanical, hydraulic or impulse methods do often not lead to acceptable yield increases. Acids of all kinds have been applied to remove iron(III) and manganese(III,IV) clogging, although pH values of < 1.0 are required before any significant dissolution takes place. This treatment does not only affect substances in adjacent geology but also well construction materials and technical equipment. Alternatives for acidization were researched and developed at the Technical University of Aachen (RWTH) in 1990’s by Prof. Dr. Treskatis and Dr. Houben. Since then iron(III) and manganese(III,IV) are removed by pH-neutral reductants with 50 times greater dissolving capacity than hydrochloric acid at pH 1.0 in identical molar concentration. The closed-circuit injection technique was proved to be the only method to transfer chemical agents as far as the borehole wall in a study by Dresdner Groundwater Center on behalf of German Gas and Water Association in 2003. Low pressure circulation based on large volume flow is accomplished by means of state-of-the-art gravel washers. The application of pH-neutral dissolvers by closed-circuit injection has proved its effectiveness not only in Germany, but also in Switzerland, Austria, Netherlands, Spain, UK, UAE and Peru. Our case study documents its successful introduction in Finland 2020. Until then stand-by acidization had been the only means of battling well ageing. Research funds enabled rehabilitations in different parts of the country resulting in unexpected high yield increases.
Advanced Groundwater Management In Namibia: Introducing The New National Groundwater Database Growas Ii	Marius	Quinger	Namibia	2013	groundwater management, groundwater monitoring
Abstract The key towards modern groundwater management lies in a profound strategy from monitoring data collection over data processing and information management to clear reporting on the development of groundwater resources. Only thus planners are enabled to take informed decisions towards sustainable use and well-keeping of available groundwater. A core in this strategy is the digital database in which all relevant data and information is stored, handled and displayed. It is thus that the Namibian Ministry of Agriculture, Water and Forestry (MAWF) decided to replace within the activities of the Namibian–German cooperation project “Groundwater for the north of Namibia”, the existing national groundwater database GROWAS with the completely new development of the GROWAS II version. Through the experience of the project partner BGR (Federal Institute for Geosciences and Natural Resources) the focus was put on the critical issue of data quality control. As the analysis of the old system indicated unclear data operation procedures as a major source of errors, improved user-friendliness was high on the agenda for the new database. Developed closely to the needs of Namibian Water Authorities, GROWAS II features a GIS-based graphical user interface (GUI) with a vast range of query functions, a modular system including time series tools, hydrochemistry, licenses for abstraction application and groundwater status reporting functions, among others. Quality control is secured through different measures like the “fosterage” option which allows the input of data into a temporary status with restricted access until released by senior experts, the quick and direct interaction with Google Earth to verify locations and the extensive use of look-up tables and descriptive keys in alignment with other regional geo-databases. Furthermore, data entries can be marked according to their estimated reliability with traffic light coding. These measures should ensure that only good quality data will be added in the future. Upcoming development steps are the practical tests of the single modules in day-to-day use, the integration into or exchange with other information systems and the improvement of older existing data as far as possible. Namibia will thus be better prepared for future groundwater challenges.
Robust Hydrogeological Conceptual Models Through Interdisciplinary Characterisation – A Case Study	Zandri	Rademan	South Africa	2023	conceptual model, Geophysics, geotechnical, hydraulic testing, interdisciplinary
Abstract The basis of a hydrogeological conceptual model is the comprehensive characterisation of the groundwater system. This ranges from discrete hydraulic feature analysis to local-scale testing to integrated regional-scale aquifer system conceptualisation. Interdisciplinary data integration is critical to each level of characterisation to gain a realistic, yet simplified representation of the hydrogeological system based on various data sources. Incorporation of geological datasets, including (but not limited to) structural and lithological mapping, geotechnical core logs and geophysical surveys, in conjunction with a tailored selection of hydraulic testing techniques, are often underutilised by hydrogeologists. Yet, the contribution of these alternative hydraulic datasets cannot be overstated. A recent hydrogeological assessment and feasibility study forming part of the planned expansion project for a base-metal mine in the Northern Cape, South Africa, offers an ideal, practical example. The localised nature of the project area and the inherently complex geological setting required a more detailed conceptual model and hydrostratigraphic domaining approach. Highly heterogeneous stratigraphy and strong structural aquifer controls necessitated characterisation by reviewing, testing and analysing various datasets. Exploratory core datasets, hydraulic aquifer tests, geological and downhole geophysical datasets, and statistical Rock Quality Designation—hydraulic conductivity relationships were interpreted to produce meaningful, refined hydraulic process identifications. A comprehensive local groundwater framework, discretised into various hydrostratigraphic units and structural domains with specified hydraulic parameters, was incorporated to provide a novel, more robust conceptual understanding of the unique hydrogeological system.
Investigation of Sustainable Groundwater Resource Supply in the Crystalline Basement Aquifer at Matoks (Mokomene) ,in Molemole Municipality, Limpopo Province, South Africa.	Ronald	Ramathieledza	Molemole Municipality, Limpopo, South Africa	2017	Groundwater resource supply, crystalline basement aquifers, geophysical techniques, magnetic anomalies, borehole yield, water quality.
Abstract Water is an essential resource for livelihood (humans, animals and plants) and without water there is no life on earth. Worldwide over 1.1 billion people do not have access to safe water and more than 1 billion people are living in water stressed areas. The scarcity of water is more intense in developing countries where statistics show that 67% of the rural population have no access to safe water supply. Detailed geohydrological investigation and chemical analysis were conducted in crystalline basement rocks at Matoks in Capricorn District, Limpopo province of South Africa to determine the groundwater availability and its quality for human consumption. Groundwater potential was identified by the use of geophysical techniques (electromagnetic profiling, magnetic profiling). Traverse lines were set based on the information acquired from the desktop studies (DWS-mapped structures such as faults, joins or lineaments, Topographical map, Google Earth and geological mapping). Drilling positions were configured based on the magnetic anomalies, followed by the drilling of selected targets. Water strikes ranges were at 20 – 36 mbgl, these showed that the area has shallow aquifers. The aquifer response under applied pressure produced a blow yield ranging from 3-20 l/s. The recommended borehole yields ranges from 1 – 6 l/s which makes about 2 747.52 m³/day and the average transmissivity was 41.04 m²/day. Water samples were analysed through the use of various techniques, namely: AAS, IC, IC-PMS, water quality from the study area ranges from class I to class IV, which is good to poor water quality according to South African National Standards. The aquifers at Matoks can meet the present water abstraction demand and the aquifers are having good to poor water quality.
Contaminated soil and groundwater: Vacuum Enhanced Recovery as an alternative method	Ernest	Rambau	South Africa	2015	Vacuum Enhanced Recovery, hybrocarcon contamination
Abstract Vacuum Enhanced Recovery (VER) has widely been applied in many hydrocarbon contaminated site to recover liquid hydrocarbon from the subsurface Hydrocarbon contamination to groundwater and soil is usually as results of leak or release. Different technologies and method exist to treat contaminated groundwater and soil through hydrocarbon. This paper focuses on the efficiency of VER as alternative method to the site where over 6 000 litres of petrol leaked to the subsurface over a period of time. The application of VER involves creating a capture zone in a particular monitoring well by increasing the hydraulic gradient towards that particular well or set of wells affected by hydrocarbon.
The use of Coal Combustion Residues for the stabilisation of mines and the treatment of mine drainage	Kelley	Reynolds-Clausen	South Africa	2023	CCP, coal combustion residue, coal ash, mine backfilling
Abstract Coal Ash Beneficiation is a government imperative for South Africa, and Eskom generates approximately 34 million tons of coal ash annually from their 14 pulverised coal fuel plants. It is estimated that there are approximately 6,000 abandoned coal mines in South Africa, of which 2,322 are classified as high risk, contributing to subsidence and the generation of acidic mine drainage. It is envisaged that coal ash could offer a support medium for the mines and neutralise the acidic mine water due to its alkaline nature. The Department of Fisheries, Forestry and the Environment has supported the initiative but has requested a means of modelling possible contamination due to placing the coal ash in these environments. To this end, laboratory trials were completed to generate the initial model and a controlled pilot site was established to validate the model’s accuracy. This trial evaluated stabilised and unstabilised coal ash as a means of acid water management. The laboratory trials showed that the ash could neutralise the pH of the mine water from approximately 2 to 7; this was sustained for the test period. In addition, sulphate and iron were significantly reduced in the treated water. The laboratory and site work results will be detailed in this presentation.
Comparison of Topographical and Seasonal Variation of Geochemical Parameters in the Kuils River and Steenbras River	G.D.	Rezelman	Western Cape	2017	geochemical parameters, Topographical Variation
Abstract Water resources are a great concern in South Africa, more specifically the Western Cape. Therefore, a need has developed to understand the processes that may affect these precious resources. In the Western Cape large proportions of these resources are in the form of streams originating in untouched mountainous areas. However, as these streams continue towards the ocean they are faced by many threats. Alien vegetation, the destruction of river beds and abstraction from streams and boreholes threaten to dry up these resources. Additionally, pollution from fertilizers, sewage treatment plants as well as urban and industrial run-off contaminate these resources. The influx of pollutants, such as fertilizers, usually varies between seasons as it is only applied at certain times of the year. However, pollutant concentrations are not only linked to riparian land-use but are largely affected by climate changes as well. Processes such as surface run-off, along with first flush events and dilution control the nutrient concentrations in the streams. Although water is a renewable resource, it is not replaceable. This project will look at the streams’ self-purification potential. This refers to the processes within the rivers that lead to an in situ reduction of contaminants and pollutants. For example, contaminants and pollutants in rivers can be reduced by particle settling, plant and microbial uptake as well as chemical processes such as redox reactions and complex formation. For this project, pollution will be categorized into two different groups: nutrients and major ions from both point sources and non-point sources. The relevant nutrients analysed in this study are: nitrate, ammonium, phosphate and sulphate; and the major ions analysed are: Calcium (Ca), Sodium (Na), Potassium (K), Aluminium (Al), Iron (Fe) and Manganese (Mn). These will be analysed in conjunction with several physico-chemical parameters: temperature, pH, conductivity, total dissolved solids (TDS), salinity, oxidation reduction potential (ORP) and alkalinity. Analysing these parameters will allow us to measure the effects these processes have on pollution concentrations in the rivers and how climate changes facilitate these processes. For this study, the polluted Kuils River will be analysed and compared to the Steenbras River, which lacks major direct contaminants. This stream will this mainly serve as a ‘control’. Since this study will only be completed at the end of 2017, full conclusions have not been drawn yet. Therefore, this paper will highlight the findings thus far.
A framework for conjunctive use at local government level	Kornelius	Riemann		2015	Conjunctive use, IWRM, framework
Abstract Conjunctive use of surface water and groundwater resources offers huge advantages to municipalities. It can significantly increase the resilience of the municipal water supply to drought situations. Optimal use and integration of different sources would result in a yield of the total system that is higher than the combined yield of each source separately. However, integrated water resource management (IWRM) in general and planned conjunctive use of both groundwater and surface water resources in particular have not been successfully implemented yet in South Africa. Six selected case studies of municipalities across South Africa, which utilize both surface water and groundwater for the water supply to specific towns, have undergone a review of their current water governance provisions wrt groundwater, surface water and conjunctive use. The review has been based on a questionnaire for direct interaction with the local government officials, supported by other readily available documents such as municipal Integrated Development Plan (IDP) and Water Services Development Plan (WSDP), municipal websites, Blue Drop and Green Drop Assessment Reports, Municipal Strategic Self-Assessment (MuSSA) and the All Towns Reconciliation Strategy reports. These case studies reveal the different institutional arrangements for water resource management and water supply services that exist in municipalities. The advantages and disadvantages of the institutional arrangements for each case study have been determined. Problem areas identified include split of responsibilities for surface water and groundwater resources between different institutions, lack of financial and HR support within the government spheres, lack of formal and structured stakeholder engagement, insufficient monitoring for both sources, inter alia. Based on this comparative study of different municipalities, a draft framework of optimal institutional arrangements and governance provisions at local government level is developed to support the integration and optimisation of surface water and groundwater supply. The proposed framework is based on three pillars; viz. leadership and clear structures within the responsible local government institution, formal engagement with all relevant internal and external stakeholders and a sufficient monitoring network that supports the stakeholder engagement and decision making.
Water Quality of Cape Town Aquifers – The WWQA African Use Case	K	Riemann	South Africa	2023	WWQA, Water quality, Awareness
Abstract Globally, rivers, lakes and groundwater face complex anthropogenic water quality alterations posing risks to human health, food security and ecosystems. The World Water Quality Alliance (WWQA) forms an open, global consortium, pooling expertise on water quality science and technology innovation and providing a participatory platform for water quality assessments and co-designing tailored and demand-driven services. It addresses priority topics relevant to water governance, scalable water solutions and emerging issues in water management. The African Use Cases provided an initial testbed that puts the quality of surface water and groundwater into the context of the local 2030 Agenda and its multiple linkages across the Sustainable Development Goals. Central to the initial Africa Use Cases was the integration of in-situ, remote sensing-based earth observation and modelling data to derive the best possible current state of water quality (baseline). Of the three African Use Cases, “Cape Town’s Major Aquifer Systems” focused mainly on groundwater quality in an urban environment. One of the success factors for the Cape Town Aquifer Use Case was the ability of the team to integrate the three different data types of the triangle approach on a sub-catchment scale. This required understanding the complex surface and groundwater systems and their interaction (flow paths and fluxes) in the urban environment. A robust stakeholder engagement process and the introduction of transformative art also drove the success of the Cape Town Use Case. The outcomes of this process will be presented and discussed in this presentation.
Hydraulic Tests Of Strong Artesian Boreholes: Well-Head Construction And Test Design	Kornelius	Riemann	National	2013	hydraulic tests, artesian conditions, aquifer
Abstract Artesian boreholes are a common feature worldwide in confined aquifers. However, the hydraulic testing of these boreholes and estimation of aquifer properties from such tests still pose a challenge for hydrogeologists. Common hydraulic tests, such as step-drawdown or constant discharge rate tests require a static water level at the start of the test, and the measurement of drawdown (increasing over time) and abstraction rate (fixed for a period of time). Usually, when undertaking a pumping test in an artesian borehole, the drawdown is measured from ground level, and the drop in hydraulic head between static pressure and ground level is often ignored. This also implies that the starting time of the test is not at the static water level. A constant head test, set at ground level, is the other option. However, the decrease in flow rate is not only dependent on the hydraulic properties of the aquifer, but also masked by pipe hydraulic effects within the well. This kind of test would also limit the available drawdown to be utilised for the test. Hence, it was required to develop a method for undertaking hydraulic tests in strong artesian boreholes allowing for the drawdown to fluctuate between above and below ground and avoiding the pitfalls described above. The solution is a specially designed and constructed well-head for the installation of the pump and monitoring equipment prior to the hydraulic test. The standard tests are slightly modified and will only be carried out after sealing the well-head and reaching static hydraulic pressure. The recommended well-head construction and subsequent hydraulic tests were carried out at a strong artesian borehole in the Blossoms Well-field, south of Oudtshoorn in the Western Cape of South Africa.
An Overview of long-term groundwater development and management – 20 years of Hermanus wellfields	Kornelius	Riemann	South Africa	2023	Monitoring, groundwater management, wellfield development
Abstract Hermanus was originally supplied from springs and groundwater until the De Bos Dam was built in the 1950s. Due to increasing water demand, the municipality commenced wellfield development in 2002. The first wellfield comprised 3 boreholes, of which one borehole was later decommissioned due to reduced yield. Three additional boreholes were drilled recently to ensure abstraction capacity within the licence limits. A second wellfield was developed in the Hemel-en-Aarde Valley north of Hermanus. To ensure the sustainable management of the shared resource and minimise environmental impacts, a monitoring committee was established with all relevant roleplayers, other users, civil society, environmental groups and various commenting and regulatory authorities. A comprehensive monitoring network was established to assist with the scheme’s management and ensure that environmental impacts are minimized. The long-term monitoring (up to 20 years) shows that the groundwater abstraction from the Gateway Wellfield does not impact the environment and other users or increase the risk of saline intrusion. Identified impacts have been mitigated with the assistance of the monitoring committee. The municipality aims to provide at least half of the town’s water demand from groundwater and establish conjunctive use operation between surface water from the De Bos Dam and groundwater from these wellfields. The wellfields ensured sufficient water for the municipality when De Bos Dam’s water levels declined significantly during the Western Cape droughts in 2011 and 2017. The presentation will provide examples of the long-term monitoring records and trends.
Feasibility And Implementation Plan For Groundwater Resource Development Of The Malmani Dolomites Within The Olifants River Water Supply System	Kornelius	Riemann	Olifants River	2019	development
Abstract The Reconciliation Strategy for the Olifants River Water Supply System (ORWSS) indicated that the surface water resources in the Olifants Water Management Area are already overallocated, and recommended that the potential of the Malmani Subgroup dolomites along the Limpopo and Mpumalanga escarpment as an additional water resource be investigated. The Feasibility Study for Groundwater Resource Development of the Malmani Dolomites within the ORWSS considered among other aspects the hydrogeology, hydrology, artificial recharge potential, groundwater - surface water interaction and wellfield design options. A key aspect of the analysis and study findings was determining the amount of water that can be provided additionally, as the groundwater development was conceived as impacting on and reducing the ORWSS system yield. Hence, the implementation strategy was designed to address this mistrust in the groundwater potential and to allow for increasing the confidence in the yield estimates over time. The implementation strategy identified several possible recipients of the water, influencing the prioritisation of wellfield development. The scheduling of implementation should first address community water supply shortfalls in the area, followed by releases to the Olifants River to cater for environmental requirements and then direct development for bulk water supply schemes. Out of the twelve identified wellfield target zones (WFTZ), eleven are recommended for potential wellfield development. Seven Malmani Subgroup dolomite aquifer WFTZs have high groundwater development potential with proven high borehole yields (>10 l/s) and are recommended for priority full-scale wellfield development, through a phased monitor-model-manage approach. The total proposed groundwater development comprises 48 wellfields with a combined yield of >40 million m3/a. Although several organisations are suitable for implementing the scheme, or parts thereof, the DWS should maintain oversight function to ensure that the several parts of the scheme development are implemented in a coherent manner and in accordance to the implementation strategy.
‘Groundwater Reserve’ – A Critical Review	Kornelius	Riemann	National	2013	Groundwater reserve
Abstract The concept of the ‘Groundwater Reserve’ is enshrined in the National Water Act that stipulates that a classification of all significant water resources must be undertaken and the Reserve requirements be determined and gazetted. The Reserve covers two different aspects, the Ecological Reserve to protect the water dependent ecosystems and the Basic Human Needs (BHN) Reserve to ensure that all people who depend on that water resource have sufficient water for their livelihood. The approach for determining and implementing the Reserve that was developed for surface water resources was adopted for groundwater resources as provided for in the Groundwater Resource Directed Measures (GRDM) Manual, inter alia. However, there is no separate ‘Groundwater Reserve’, but rather a groundwater component of, or contribution to, the ecological Reserve and BHN. Hence, the implementation of this methodology often results in undesirable outcomes and is one of the inhibiting factors for sustainable groundwater development, as some of the aspects and methods are not applicable to groundwater and not appropriate for implementation. The current separation of the ‘Groundwater Reserve’ determination process from the ecological Reserve determination emphasises this pitfall of the process and methodology. This paper provides a critical review of the current concept of the ‘Groundwater Reserve’ and its implementation based on several case studies. It concludes with recommended changes to the standard methodology and a possible way forward for developing an appropriate methodology for addressing and protecting the groundwater contribution to both the ecological and BHN Reserve.
Hydraulic tests of strong artesian boreholes; wellhead construction and test design	Kornelius	Riemann		2015
Abstract Artesian boreholes are a common feature worldwide in confined aquifers, but the hydraulic testing of these boreholes, and estimation of aquifer properties from such tests, still poses a challenge for hydrogeologists. Common hydraulic tests, such as step-drawdown or constant-discharge rate tests require a static water level at the start of the test, and the measurement of drawdown (increasing over time) and abstraction rate (fixed for a period of time). Usually, when undertaking a pumping test in an artesian borehole, the drawdown is measured from ground level, and the drop in hydraulic head between static pressure and ground level is often ignored. This procedure also implies that the starting time of the test is not at the static water level. A constant-head test, set at ground level, is the other option. However, the decrease in flow rate is not only dependent on the hydraulic properties of the aquifer, but also masked by pipe hydraulic effects within the well. This kind of test would also limit the available drawdown to be utilized for the test. Hence, it was required to develop a method for undertaking hydraulic tests in strong artesian boreholes, allowing for the drawdown to fluctuate between levels both above and below ground and avoiding the pitfalls described above. The solution is a specially designed and constructed wellhead for the installation of the pump and monitoring equipment prior to the hydraulic test. The standard tests are slightly modified and are only undertaken after sealing the wellhead and reaching static hydraulic pressure. The recommended wellhead construction and subsequent hydraulic tests were implemented at a strong artesian borehole in the Blossoms Wellfield, south of Oudtshoorn in the Western Cape province of South Africa.
Groundwater Resource Protection: State-Of-The-Art, Challenges and Research Needs	Kornelius	Riemann	National	2017	Resource protection, Water Availability
Abstract Water plays a significant role in the economies of the agricultural, business and industrial sectors. Expanding populations, economies and climate change have put pressure on the quality and availability of water resources in South Africa, therefore water resource protection becomes increasingly important for sustainable water supply management. Hence, a review of the state-of-the-art of water resource protection in South Africa has been undertaken on behalf of the WRC, applying the water resource governance framework. Gaps in scientific understanding and implementation with regards to water resource protection have been identified through literature review and discussions with stakeholders and experts. Aiming to improve the water resource protection in South Africa, a research strategy has been developed to tackle the most relevant of the identified gaps. The legislation in South Africa with respect to water resource protection is state-of-the-art and one of the best in the world. However, there is still space for improvement in that the different acts need to be aligned better to facilitate cooperative governance and improve the implementation of the legislation. Regulations and guidelines are plentiful covering most of the relevant activities and various water resources. The main challenge for implementing the intent of the National Water Act with respect to groundwater resource protection is that the standard methodology for determining Resource Directed Measures (RDM) was developed for surface water resources and is not applicable to groundwater or wetlands. Furthermore, classification and Reserve determination are mostly carried out at a scale that is insufficient for effective groundwater resource protection. The methodology requires update to incorporate potential impacts of climate change, changing land use and changing demographics. The different elements of the RDM methodology need to be aligned. There is also often an insufficient spatial and temporal distribution of monitoring networks to effectively manage groundwater resources. Integrated catchment management can provide a solution to the current state of water resource protection. However, this must be based on a scientific understanding of the complex natural system. The different challenges, research needs and possible solutions are demonstrated on a case study of Stanford Aquifer.
Governance and Management of Water Resource in the SA Context - A Review	Kornelius	Riemann		2015
Abstract Water management is a difficult and complex business requiring appropriate institutional arrangements as well as guidance and support from government, which is often unable to act effectively to address day-to-day water resource management (WRM) issues. Theoretically, water as a 'common pool resource' is best managed by users self-organised at a local level and within a basin framework. Water users and other stakeholders have detailed and up-to-date local knowledge as well as an interest in ensuring effective management to share water equitably between different users and to control pollution. This approach is supported by South Africa's National Water Act (NWA), which provides for the establishment of Catchment Management Agencies (CMAs) to perform a range of WRM activities within the framework of a National Water Resource Strategy (NWRS). Hence, water resource management in general and conjunctive use in particular requires cross sector and cross level cooperative governance. Relevant institutions include the DWA at national and regional level, the CMA, if established, provincial departments that might impact on the water resources, water user associations, water services authorities, water services providers, water boards, and individual water users. These institutions are responsible for various activities and often require some level of inter- and intra-institutional cooperation. Ideally, multiple organisations, policies, legislation, plans, strategies and perspectives should be involved in water-related decision-making, which in turns creates complex leadership challenges. Globally, the lack of sustainable groundwater management can be ascribed to poor governance provisions. These include, but are not limited to, institutional arrangements and political will, including fragmented and overlapping jurisdictions and responsibilities, competing priorities, traditional approaches, rights and water pricing systems, diverging opinions, incomplete knowledge, data as well as uncoordinated information systems. Adding the poor operational and maintenance issues, decision-makers often view groundwater as an unreliable resource and are hesitant to make significant investments in groundwater infrastructure and capacity. The recent Worldbank and WRC report on groundwater governance in South Africa revealed that the technical, legal, institutional and operational governance provisions were found to be reasonable at the national level but weak concerning cross-sector policy coordination. At the local level, basic technical provisions such as hydrogeological maps and aquifer delineation with classified typology are in place but other governance provisions such as institutional capacity, provisions to control groundwater abstraction and pollution, cross-sector policy coordination and the existence and implementation of groundwater management action plans are weak or non-existent. It appears from this review that the major hindrances for sustainable groundwater governance and more so for integrated water resource management and conjunctive use scenarios are the discrepancy between groundwater and surface water provisions in the relevant legislation, associated guidelines and their implementation at regional and local, and the lack of skills and clear responsibilities for implementing water resource management actions at municipal level. This is demonstrated with several case studies.
Understanding and Affecting Water Consumer Behavior Using Technological Interventions at a Primary School in Stellenbosch	C.	Ripunda	Stellenbosch	2017	Water Consumption, Interventions
Abstract This paper studies and reports the water usage behavior of a primary school. Three interventions were implemented to change this behavior to support water conservation. The aim of the study was to quantify the effects of the technological interventions on behavioral change. The school’s water usage pattern was found to be predictive and regular except for daily losses, which were measured and extrapolated from midnight to early morning volumes. The water usage distribution was Gaussian with the mean being centered around break time. The interventions were able to reduce water consumption of the school by 44% when compared to the use of a school across the road where the interventions were not implemented.
A methodology for uncertainty quantification of dewatering volumes under the context of open-cast mining	C	Rivera Villarreyes		2023	FEFLOW, Groundwater Modelling, mining, PEST, PESTPP
Abstract Groundwater modelling at the mine sites involves assumptions from the geological model, mining stages, parametrization, and fractures, among others. Modelling work mainly focuses on calibrating against historical measurements before operations (pre-mining) or afterwards (transient calibration). Calibration is carried out mainly with gradient-based algorithms. However, the majorlimitation is the number of model runs, since the number of parameters can easily reach hundreds or more. PEST has become the common tool for parameter estimation. The Jacobin calculation required for the Levenberg Marquardt algorithm requires several model runs. This, a limited factor for the calibration and, subsequently, uncertainty quantification. The next generation of PEST, named PESTPP, is gained popularity in the groundwater community. The great advantage of PESTPP,, compared to the classical PEST, is its new module, Iterative Ensemble Smoother (IES). PESTPP-IES covers both parameter estimation and uncertainty quantification in one goal. Its empirical formulation of the Jacobian matrix reduces the number of runs; thus, the numerical bottleneck can be significantly reduced. PESTPP-IES has been extensively tested in an open-pit mine at the geological complex conditions in the Peruvian Andes. The work involves the task of model simplification, e.g., from a regional model to a detailed local pit model, calibration and uncertainty quantification of pit dewatering volumes. Detailed model was kept calibrated based on hydraulic-head measurements, and dewatering volumes were predicted. All these consider transient changes in the mining plan within the same FEFLOW model. Results validate the methodology and practicability in mining applications.
A Case Study on Capacity Development in Rural Groundwater Supply in Acholiland, Northern Uganda	K	Robey	Northern Uganda	2023	Uganda, capacity development, Geophysics, handpump functionality assessments, rural groundwater supply, Water quality
Abstract Groundwater is the most important source of potable water in rural areas of Acholiland, a sub-region of northern Uganda. Installation of handpumps has been the focus of local government and international aid to provide safe drinking water in Uganda. However, non-functional handpumps are one reason for the abandonment of groundwater resources. For handpumps to be sustainable for years, appropriate siting and construction is required, as well as monitoring. This is common knowledge to specialists working in rural supply, but gaps in knowledge transfer and field skills may exist for the persons installing and maintaining handpump wells. This is a case study of a ten-day field campaign designed to train local participants who actively work in the rural groundwater supply sector. Nine non-functional handpump sites were identified for repair and hydrogeology and geophysical studies. A non-governmental organization, IsraAID, along with Gulu University implemented training by hydrogeology specialists to build local capacity. The training included handpump functionality tests, downhole inspections, electrical resistivity tomography surveys, and water quality sampling, including a novel Escherichia coli test that did not require an incubator. Functionality tests and downhole inspections provided simple but effective ways to assess handpump and well issues. Training in water quality empowered the participants to complete rapid assessments of the quality of the water and start monitoring programs. The success of the project was based on collaboration with multiple organizations focusing on the development of local capacity. The lessons learnt from this campaign should be considered for other rural groundwater supply scenarios.
In situ iron removal: Innovative option for preventing production borehole clogging	Kate	Robey	Karoo	2015
Abstract Worldwide many aquifer systems are subject to hydrochemical and biogeochemical reactions involving iron which limit the sustainability of groundwater schemes. This mainly manifests itself in clogging of the screen and immediate aquifer with iron oxyhydroxides resulting in loss of production capacity of the borehole. Clogging is caused by chemical precipitation and biofouling processes which also manifests in South African wellfields such as the Atlantis and the Klein Karoo Rural Water Supply Scheme. Both wellfields have the potential to provide a sufficient, good quality water supply to rural communities, however clogging of the production boreholes has threatened the sustainability of the scheme as quality and quantity of water is affected. Repeated rehabilitation of the affected boreholes using techniques such as the Blended Chemical Heat Treatment (BCHT) method does not provide a long term solution. Such treatments are costly with varying restoration of original yields achieved and clogging recurs with time. Currently, the research, management and treatment options in South Africa have focused on the clogging processes which are complex and site specific making it extremely difficult to treat and rectify. This project attempts to eliminate the cause of the clogging which is elevated concentrations of dissolved iron. High iron concentrations in groundwater are associated with reducing conditions in the aquifer allowing for dissolution of iron from the aquifer matrix. These conditions can be natural- and/or human-induced. Attempts to circumvent iron clogging of boreholes have focussed on increasing the redox potential in the aquifer to prevent dissolution and facilitate fixation of the iron in the aquifer matrix. Various in situ treatment systems have been implemented successfully overseas for some time. However, in South African in situ treatment of iron has only been a theoretical approach. Based on experience from abroad the most viable option to research and apply elimination of ferrous iron in South African aquifer systems would be through the in situ iron removal treatment The objective of this paper is to set out the experience from abroad and to outline the initial results of this treatment. A pilot plant for testing the local applicability of this method was constructed at the Witzand wellfield of the Atlantis primary aquifer on the West coast of South Africa.