Conference Abstracts

All Abstracts were presented at the Groundwater Conferences

Displaying 701 - 750 of 795 results

Title	Presenter Name	Presenter Surname	Conference year	Keywords
Building Of A Gravity Lysimeter To Represent An Ash Backfilled Opencast Coal Mine.	Kamohelo	Mokoena	2019	Poster, Lysimeter, coal mine
Abstract Millions of tons of coal ash are produced across the globe, during coal combustion for power generation. South Africa relies largely on coal for electricity generation. The current disposal methods of coal ash are not sustainable, due to landfill space limitations and operational costs. One way/means of disposing of coal ash that could provide environmental and financial benefits; is to backfill opencast mines with the ash. However, a limited number of studies have been conducted to assess the feasibility of this method in South Africa. Thus the aim of the experiment is to monitor bulk ash disposal under field conditions to improve the understanding of the geochemical and hydrogeological processes occurring during the actual deposition of coal ash in opencast coal mines. To achieve the aim (1) a gravity lysimeter will be built containing both mine spoils and coal ash representing field conditions; (2) the factors (CO2, water level and moisture content) affecting acid mine drainage will be monitored in the lysimeter and (3) the change in the quantity and quality of the discharge released from the lysimeter.
Physico-Chemical Assessment of Groundwater in the Orange Water Management Area	Olma Tsakani	Makonto	2015
Abstract The groundwater quality of the Orange Water Management Area (OWMA) was assessed to determine the current groundwater status. Groundwater is of major importance in the Orange Basin and constitutes the only source of water over large areas. Groundwater in the OWMA is mainly used for domestic supply, stock watering, irrigation, and mining activities. Increase in mining and agricultural activities place a demand for the assessment of groundwater quality. The groundwater quality was assessed by collecting groundwater samples from farm boreholes, household boreholes, and mine boreholes. Physical parameters such as pH, temperature and Electrical Conductivity (EC) were measured in-situ using an Aquameter instrument. The groundwater chemistry of samples were analysed using Inductively Coupled Plasma Mass Spectrometry, Ion Chromatography, and Spectrophotometer for cations, anions and alkalinity respectively. The analyses were done at Council for Geoscience laboratory. The results obtained indicated high concentration of Nitrate (NO3), EC, sulphate (SO4), Iron (Fe), and dissolved metals (Chromium, Nickel, Copper, Zinc, and Lead). The concentrations were higher than the South African National Standards (SANS) 241 (2006) drinking water required guideline. The OWMA is characterised by the rocks of the Karoo Supergroup, Ventersdorp Supergroup, Transvaal Supergroup, Namaqua and Natal Metamorphic Province, Gariep Supergroup, and Kalahari Group. Groundwater is found in the sandstones of the Beaufort Group. Salt Mining occurs in the Namaqua Group, hence the high concentration of EC observed. High EC was also found in the Dwyka Group. The salt obtained from the pans underlain by the Dwyka Group rocks has relatively high sodium sulphate content, this probably results from oxidation of iron sulphate to sulphate. Therefore, high concentration of SO4 is due to the geology of the area. High concentration of NO3 is due to agricultural activities, whereas high concentration of EC, Fe, SO4 and dissolved metals is due to mining activities.
Development of United Nations Framework Classification for Resources (UNFC) for Groundwater Resources Management	Peter	van der Keur	2023	SDGs, UNFC, common pool resources, subsurface geo-resources, sustainable groundwater resources management
Abstract There is an urgent need to support the sustainable development of groundwater resources, which are under increasing pressure from competing uses of subsurface geo-resources, compounded by land use and climate change impacts. Management of groundwater resources is crucial for enabling the green transition and attaining the Sustainable Development Goals. The United Nations Framework Classification for Resources (UNFC) is a project-based classification system for defining the environmental-socio-economic viability and technical feasibility of projects to develop resources and recently extended for groundwater. UNFC provides a consistent framework to describe the level of confidence in groundwater resources by the project and is designed to meet the needs of applications pertaining to (i) Policy formulation based on geo-resource studies, (ii) Geo-resource management functions, (iii) Business processes; and (iv) Financial capital allocation. To extend use in groundwater resources management, supplemental specifications have been developed for the UNFC that provide technical guidance to the community of groundwater professionals to enhance sustainable resource management based on improved decision-making. This includes addressing barriers to sustainably exploiting groundwater resources, avoiding lack of access to water and also related to ‘common pool resources’ in which multiple allocations are competing with domestic water supply (e.g. geo-energy, minerals, agriculture and ecosystems, and transboundary allocation of natural resources). UNFC for groundwater resources is designed to enhance governance to protect the environment and traditional users while ensuring socio-economic benefits to society. Consequently, it is a valid and promising tool for assessing both the sustainability and feasibility of groundwater management at local, national and international levels.
Characterisation And Protection Of Deep Aquifers In South Africa: Characterisation	Francois D	Fourie	2017	Deep aquifers, Aquifer characterization, groundwater flow, Groundwater Quality
Abstract This paper describes the characteristics of the deep aquifer systems in South Africa as derived from the available data. The study formed part of the larger WRC project K5/2434 (Characterisation and Protection of Potential Deep Aquifers in South Africa). A review of the available literature relevant to potential deep aquifers in South Africa was done to allow characterisation of these aquifer systems. In addition, data obtained from the geological logs of the SOEKOR and KARIN boreholes were considered. This paper focuses on deep aquifers in 1) the Karoo Supergroup, 2) the basement and crystalline bedrock aquifers, 3) the Table Mountain Group, 4) the Bushveld Igneous Complex and 5) the dolomites of the Transvaal Supergroup. From the available data the deep aquifer systems are described in terms of the following characteristics: lithology, occurrence, physical dimensions, aquifer type, saturation level, heterogeneity and degree of isotropy, formation properties, hydraulic parameters, pressurisation, yield, groundwater quality, and aquifer vulnerability. The results of the study show that the deep aquifer systems of South Africa are generally fractured hard-rock aquifers in which secondary porosity was developed through processes such as fracturing and dissolution. The primary porosity of most of the rocks forming the aquifers is very low. Apart from the dolomite aquifers, most of the water storage occurs in the rock matrices. Groundwater flow predominantly takes place along the fractures and dissolution cavities which act as preferential pathways for groundwater migration. The aquifers are generally highly heterogeneous and anisotropic. The deep aquifers are generally confined and associated with positive hydraulic pressures. The groundwater quality generally decreases with depth as the salinity increases. However, deep dolomite aquifers may contain groundwater of good quality. Due to the large depths of occurrence, the deep aquifer systems are generally not vulnerable to contamination from activities at surface or in the shallow subsurface. The deep dolomite aquifers are a notable exception since they may be hydraulically linked to the shallower systems through complex networks of dissolution cavities. The deep aquifers are, however, very vulnerable to over-exploitation since low recharge rates are expected.
Modelling Mine Water Rebound With MODFLOW	Stephen	Fonkem	2015
Abstract A review from international literature discredits the capability of MODFLOW to simulate mine water rebound, due to the nonstandard hydrogeology of underground mine systems. The conceptual understanding is that, after cessation of dewatering, mine water inflow rates and hydraulic heads are related to the void-volume, the differences in head between the water in the mine void and head dependent source, plus natural recharge to the mine voids. The flooded mine voids in the study area are partially underlain by a dolomitic aquifer. The other head dependent source of inflow into the mine voids are the surrounding and overlying Karoo aquifers. Head independent inflow rates into the mine voids, using the long term decant rates, was estimated to be 0.2% of rainfall. During mining, dewatering occurred at approximately 3 to 6 Ml/d. The objective of the model was therefore to simulate the changes head-dependent inflow rates during the rebound period. Analysis of the water level recovery data depicted that once the mine filled up with water, the hydraulic head of the mine rose with the elastic storage coefficient value of the mine void and not the specific retention as conditions changed from unconfined to confined. A three layer model was setup, to represent the two seams mined, separated by a deep Karoo aquifer. The presence of the dolomite on the mine floor was incorporated using the general head boundary package. Head dependent influx from overlying shallow and intermediate Karoo aquifers were simulated using the river package. All model layers were simulated as confined, initially to avoid model convergence issues. The confined setup proved to be the core in simulating mine water rebound with MODFLOW. The modelling exercise showed that storage during rebound is a boundary condition. This simply means that the complexity of mine water rebound can only be achieved in MODFLOW by proper time stepping and dividing the model into different stress periods to represent the changes in storage. Rebound in the study area, modelled with 21 stress periods produced a perfect water level recovery data for the different mine compartments. This was achieved by applying storage capacities of between 0.3 to 0.006 to simulate rebound during unconfined conditions, and values of between 10-4 and 10-5 when the mine void is flooded. The results showed that the inflow from the dolomitic aquifer steadily decreased from 4121 m3/d to 0 m3/d as the mine hydraulic head increased and rose over the head in the dolomitic aquifer. During the same period, inflow from the surrounding Karoo aquifers decreased from 2422 m3/d to less than 10 m3/d. The results of the model were very important in determining the volumes of water to be abstracted from the mine voids for ash-backfilling. {List only- not presented}
Regulating the regulations for managing groundwater use to improve water security in Southern Africa: Reflection on water use licence application process in South Africa	Mfundi	Biyela	2019	water entitlement, Regulations, WARMS, Southern Africa, South Africa
Abstract In the management of water resources especially groundwater resources, implementing existing regulations is one of the much needed aspects ensuring water security through the regulated use. However, such regulations are not regulated to ensure that they served the intended purpose in their original formulation. In South Africa, a study was carried out to assess the relevance and efficient of adhering to procedural requirements during water use licence application (WULA) process. Lived-experiences and observation methods were used to collect data. The department of water and sanitation was used as a case study. Interpretative analysis approach was used to provide the meaning on the analysed information. The WARMS database was accessed where the number of days that WULA process was extracted. The regulation No. 40713 about WULA process was analysed. The five-year-data prior and post the promulgation of regulation No. 40713 were extracted from WARMS database and evaluated in terms of the duration each application took to be processed for WULA. Data on water use for abstractions from all the regions were obtained from WARMS database and assessed. Dates when applications were submitted and when such applications were finalised were analysis per month and per years for temporal analysis. The number of entitlements received during the particular period and the number of applications recommended to be declined and issued were assessed using exploratory data analysis methods. Graphical method was adapted to increase results visualisation on water use entitlements. Key results showed that the process of WULA was generally slow and reasons were provided for such outcome. However, the temporal analysis revealed an increasing trend in the post promulgation of regulation No. 40713 suggesting that regulations when re-regulated serve its intended purpose. Although such findings are not conclusive but they inform a basis for re-regulating enforcement regulations in Southern African countries with issues similar to South Africa on water entitlement.
Characterising surface water-groundwater interactions in the Vo?lvlei (Agulhas Plain), using a multi-disciplinary approach	Nabuweya	Noordien	2015
Abstract Coastal wetlands are complex hydrogeological systems in which groundwater have a significant influence on both its water balance and hydrochemistry. Differences in groundwater flow and groundwater chemistry associated with complex hydrogeologic settings have been shown to affect the diversity and composition of plant communities in wetland systems. A number of wetlands can be found across the flat terrain of the Agulhas Plain, of which the most notable is the Soetendalsvlei and the Vo?lvlei. Despite the ecological and social importance of the Vo?lvlei, the extent to which local, intermediate and regional groundwater flow systems influences the Vo?lvlei is poorly understood. The aim of this work is to characterize the spatial and temporal variations in surface water and groundwater interactions in order to demonstrate the influence of groundwater flow systems on the hydrology of the Vo?lvlei. The specific objectives of the study are; 1) to establish a geological framework of the lake sub-surface, 2) to determine the physical hydrological characteristics of the Vo?lvlei and 3) to determine the physical-chemical and isotopic characteristics of groundwater and surface water. Data collection will be done over the period of a year. Methods to be used will include the use of geophysical (electrical resistivity) to determine high water bearing areas surrounding the wetland, a drilling investigation (the installation of piezometers at 5-10m depths and boreholes at 30m depth, sediment analysis (grain size analysis, colour and texture), hydraulic (slug testing to determine hydraulic properties; hydraulic conductivity and transmissivity), hydrological (to estimate groundwater discharge; Darcy flux and hydraulic head difference between groundwater level and lake level), physical-chemical (electrical conductivity, temperature and pH) and stable environmental isotopic (oxygen and hydrogen) analysis of surface water and groundwater, to determine flow paths and identify processes. Thus far, results obtained for the geophysical survey has revealed that the sub-surface of this wetland system is highly variable. Three traverses were done on the South-Western, South-Eastern and Northern side of the wetland (See Figure 1). In VOEL1 (South west), the upper couple of meters show areas of very low resistivity, which is associated with clays, poor water quality and water which has high dissolved salts. The changing of medium to high resistivity values on the North-eastern side is usually indicative of weathered sandstone (Table Mountain Group). VOEL2 (South eastern), indicates that the subsurface is of low resistivity. These low values are the result of noticeable salt grains in the sand. VOEL3 (Northern), indicated upper layers of low resistivity, while the lower depth indicate areas of high resistivity. It is expected that the results of this study will provide a conceptual understanding of surface water-groundwater interactions and the processes which control these interactions, in order to facilitate the effective management and conservation of this unique lacustrine wetland.
Estimation of Groundwater Recharge Response from Rainfall Events in a Semi-Arid Fractured Aquifer: Case study	Phathutshedzo	Nemaxwi	2015
Abstract Estimating groundwater recharge response from rainfall remains a major challenge especially in arid and semi-arid areas where recharge is difficult to quantify because of uncertainties of hydraulic parameters and lack of historical data. In this study, Chloride Mass Balance (CMB) method and Extended model for Aquifer Recharge and soil moisture Transport through unsaturated Hardrock (EARTH) model were used to estimate groundwater recharge rates. Groundwater chemistry data was acquired from the Department of Water and Sanitation (DWS) and Global Project Management consultants, while groundwater samples were collected to fill-in the identified gaps. These were sent to Council for Geoscience laboratory for geochemical analysis. Rainfall samples were also collected and sent for geochemical analysis. An average value of rainfall chloride concentration, average groundwater chloride concentration and mean annual precipitation (MAP) were used to estimate recharge rate at a regional scale. Local scale recharge was also calculated using chloride concentration at each borehole. The results were integrated in ArcGIS software to develop a recharge distribution map of the entire area. For EARTH model, long term rainfall and groundwater levels data were acquired from the South Africa Weather Services and DWS, respectively. Soil samples were collected at selected sites and analysed. These were used to determine representative values of specific yield to use on EARTH model. 60% of the groundwater levels data for 5 boreholes was used for model calibration while the remaining 40% was used for model validation. The model performance was evaluated using coefficient of determination (R2), correlation coefficient (R), Root Mean Square Error (RMSE) and Mean square error (MSE). Regional recharge rates of 12.1 mm/a (equivalent to 1.84% of 656 mm/a MAP) and 30.1 mm/a (equivalent to 4.6% MAP) were calculated using rainfall chloride concentrations of 0.36 and 0.9 mg/L, respectively. The estimated local recharge rates ranged from 0.9-30.2 mm/a (0.14 - 4.6%) and 2 - 75 mm/a (0.3 - 11.4%) using chloride concentration of 0.9 and 0.36 mg/L, respectively. The average recharge rate estimated using EARTH model is 6.12% of the MAP (40.1 mm/a). CMB results were found to fall within the same range with those obtained in other studies within the vicinity of the study area. The results of EARTH model and CMB method were comparable. The computed R2, R, RMSE and MSE ranged from 0.47-0.87, 0.68-0.94, 0.04-0.34, 0.16-3.16, and 0.50-0.79, 0.68-0.89, 0.07-0.68, 0.15-8.78 for calibration and validation, respectively. This showed reasonable and acceptable model performance. The study found that there is poor response of groundwater levels during rainy season which is likely to be due to lack of preferential flows between surface water and groundwater systems. This has resulted in poor relationship between estimated and observed groundwater levels during rainfall season. Key words: ArcGIS, CMB, EARTH, Groundwater recharge, rainfall
Decision making with web-based geo-spatial databases coupled to groundwater models	John	Wise	2015
Abstract Model calibration and scenario evaluations of 2D and 3D groundwater simulations are often computationally expensive due to dense meshes and the high number of iterations required before finding acceptable results. Furthermore, due to the diversity of modelling scenarios, a standardised presentation of modelling results to a general audience is complicated by different levels of technical expertise. Reducing computational time In this presentation we look briefly at the use of Reduced Order Models (ROM's), which is one of the recent developments in groundwater modelling. The method allows significant speed-up times in model calibration and scenario evaluation studies. In saturated flow for example, these approaches show speed-up times of >1000 when compared to full models created with Finite Element of Finite Difference methods. These methods are demonstrated to a case study in the Table Mountain Group, in which we show a simplified parameter calibration and scenario evaluation study. Standardising presentation In order to present the results to as wide an audience as possible, the use of a web-browser as a GUI is proposed, where the web-page is coupled to a geo-spatial database and data is presented in a spatial and numeric format. The use of the spatial database manager PostgreSQL with PostGIS is proposed. Through a browser interface, users can run modelling scenarios using the ROM, which is evaluated in near real-time. Following the evaluation of the model, we show how PostGIS can spatially present data on a base-map such as google maps. In keeping with the current trends in online map customisation, viewers can interactively choose to overlay the base-map with a data-type (such as pressure or hydraulic head contours or flow direction) that is most intuitive for their level of familiarity with the data. Conclusion In using advanced modelling techniques and a simplified browser based presentation of results, high-level decisions in water resource management can be significantly accelerated with the use of interactive scenario evaluations. Furthermore, by reaching a broader audience, public participation will be significantly enhanced.
Re-inventing the Wheel - The Iterative Development of Groundwater Sustainability in Southern Africa.	Jeffrey	Davies	2015
Abstract The SADC Grey Data archive http://www.bgs.ac.uk/sadc/ provides a chronology of groundwater development within the constituent countries of the SADC region. Early reports show how groundwater development progressed from obtaining water by well digging to the mechanical drilling of boreholes for provision of water for irrigation, township development, transport networks and rural settlement. During the 1930s steam driven drilling rigs were supplanted by petrol engine driven cable tool percussion drilling. Dixey (1931), in his manual on how to develop groundwater resources based on experiences in colonial geological surveys in eastern and southern Africa, describes aquifer properties, groundwater occurrence and resources as well as water quality and groundwater abstraction methods. Frommurze (1937) provides an initial assessment of aquifer properties in South Africa with Bond (1945) describing their groundwater chemistry. South African engineers transferred geophysical surveying skills to the desert campaign during World War II. Paver (1945) described the application of these methods to various geological environments in South Africa, Rhodesia and British colonial territories in eastern and central Africa. Test pumping methods using electric dippers were also developed for the assessment of groundwater resources. Enslin and others developed DC resistivity meters, replacing early Meggar systems, produced data that when analysed, using slide rules with graphs plotted by hand, identified water bearing fractures and deeply weathered zones. Tentative maps were drawn using interpretation of aerial photographs and heights generated using aneroid altimeters. The problems faced by hydrogeologists remain the same today as they were then, even though the technology has greatly improved in the computer era. Modern techniques range from a variety of geophysical surveying methods, automated rest level recorders with data loggers to GPS location systems and a whole host of remotely sensed data gathering methods. Worryingly, using such automated procedures reduces the ability of hydrogeologists to understand data limitations. The available collection of water level time series data are surprisingly small. Surrogate data need to be recognised and used to indicate effects of over abstraction as demand grows. As the numbers of boreholes drilled per year increases the number of detailed hydrogeological surveys undertaken still remains seriously small. Has our knowledge of hydrogeological systems advanced all that much from what was known in the 1980s? Case histories from Malawi, Zimbabwe and Tanzania illustrate a need for groundwater research with well-judged sustainability assessments to underpin safe long-term groundwater supply for the groundwater dependent communities in the region.
Developing A Transboundary Aquifer Analytic Framework To Support Localised Groundwater Decision-Making Using Big Data	Zaheed	Gaffoor	2019	transboundary, big data
Abstract Big data analytics (BDA) is a modern and innovative platform of applications that include advanced analytical techniques such as data mining, statistical analysis, artificial intelligence, machine learning, and natural language processing. Regional data are generated through groundwater monitoring, remote sensing applications or global circulation models (GCM), however this is often too course for a local understanding. Groundwater managers rely on locally relevant information for effective operational decision making, however this is often missing. A Transboundary Aquifer (TBA) Analytic Framework was developed to match, integrate and model local hydrogeological data with regional earth-observation data using BDA. Drawing on the literature on BDA, a reference architecture for the TBA analytical framework was identified for application to various groundwater management scenarios in the Ramotswa Dolomitic Aquifer (Botswana - South Africa) and Shire Valley Alluvial Aquifer (Malawi - Mozambique). The TBA analytical framework allows for local clouds to store the local and regional structured and unstructured datasets and interconnecting these local clouds through a federated cloud infrastructure. In this regard, tools that are incorporated in the TBA analytical framework include data ingestion operators, data transformation operators, and feature extractors. Various machine learning algorithms and statistical techniques are incorporated in the TBA analytical framework to downscale the regional datasets. The downscaling involves selection of potential predictors and predictants variables based on data needs to address local groundwater management scenarios such as regulating groundwater abstraction to prevent groundwater depletion. Using the downscaled data the TBA analytical framework can be utilised to uncover patterns and statistical relationships in the datasets in order to model local groundwater processes such as cone of depression, groundwater levels forecasting, well protection zoning, amongst others.
Using electrical resistivity method for subsurface mapping of shallow aquifers in Heuningnes Catchment, South Africa	Kinsley	Manyama	2015
Abstract The current study investigated the subsurface of aquifers in Heuningnes Catchment focusing on aquifer characteristics for groundwater resource assessments. Surface geophysical resistivity method was adapted for mapping the shallow subsurface layers and hydrogeologic units at selected sites within the catchment. The aim was to provide a preliminary overview of the subsurface nature of aquifers within the study area, by establishing features such as geological layers, position of weathered zones, faults and water bearing layers. The multi-electrode ABEM SAS 1000 resistivity meter system, using the Wenner array, was used to obtain 2D resistivity data of the subsurface. The acquired data was processed and interpreted using Res2DINV software to produce the 2D resistivity models. The analysis of the resistivity models of the subsurface reveals maximum of four layers; sandstone, shale, poor clayed and brackish water saturated layer. On comparing the model results with the surficial geological formation of the catchment geological map, the identified layers were found to correspond with the geology of the area. The findings i) provide insights on sites that can be drilled for groundwater exploration, ii) show possible water-type variations in the subsurface. Although the results are not conclusive but they provide basis for further research work on quality and flow dynamics of groundwater. {List only- not presented} Key words: aquifer properties, hydrogeologic units, geo-electric model, electrical-resistivity method
Optimizing borehole performance through dynamic flow and chemistry profiling	Steve	Kalule	2021	Drinking water standards, Groundwater Quality, supply boreholes, remediation system, optimised well design, well profiling
Abstract Stringent drinking water standards for constituents like chromium, arsenic, and nitrates, combined with continually higher demand for groundwater resources have led to the need for more efficient and accurate well characterization. Many boreholes are screened across multiple aquifers to maximize groundwater production, and since these aquifers can have different water qualities, the water produced at the wellhead is a blend of the various water qualities. Furthermore, the water entering a well may not be distributed equally across the screened intervals, but instead be highly variable based on the transmissivity of the aquifers, the depth of the pump intake, the pumping rate, and whether any perforations are sealed off due to physical, chemical, or biological plugging. By identifying zones of high and low flows and differing water qualities, well profiling is a proven technology that helps optimize operational groundwater production from water supply boreholes or remediation systems. This frequently results in increased efficiencies and reduced treatment costs. By accurately defining groundwater quantity and quality, dynamic profiling provides the data needed to optimize well designs. Conventional exploration methods frequently rely on selecting well screen intervals based on performing and analyzing drill stem tests for one zone at a time. Using dynamic flow and water quality profiling, the transmissivity and water quality can be determined for multiple production zones in a matter of one to two days. It also allows the location and size of the test intervals to be adjusted in the field, based on real-time measurements. In this paper we discuss dynamic well profiling techniques with project case examples of characterization different types groundwater boreholes for a variety of applications and industries resulting in significant cost saving and sustainable water abstraction.
Groundwater In Sustainable Development Goal 6: The South African Case Study	Sivashni	Naicker	2019	Domesticate, South Africa, United Nations
Abstract South Africa has committed to achieving the United Nations Sustainable Development Goals (SDG's) by 2030. But what does this mean and how does groundwater fit in to this? SDG 6 in particular focuses on ensuring universal access to safe and affordable drinking water for all by 2030. SDG 6 requires that the country protects and restores water-related ecosystems such as forests, mountains, wetlands, aquifers and rivers which are essential if we are to mitigate water scarcity. To accomplish this, South Africa has proceeded to align various plans, strategies, and policies to encompass the targets of the SDG's. This paper will focus on SDG sub-goal 6.3 which incorporates improvement of water quality and sub-goal 6.6 which involves protection and restoration of ecosystems. The methodology given by the UN for the groundwater in indicator 6.3.2 stipulates that countries are required to report on "proportion of water with good ambient water quality", in South Africa however we had to domesticate the indicator i.e. render it suitable for South African conditions so we changed the methodology to "proportion of water the conforms to the Water Quality Objectives (WQO's)" but there are virtually no WQO's developed for groundwater. Four core groundwater quality parameters (Electrical Conductivity, pH, Nitrate and Sulphate) are available through ZQM stations categorized through 65 hydrogeological (Vegter) regions. Groundwater water quality baseline is calculated as a reference period/range per hydrogeological region. For SDG 6.6, the indicator required for groundwater is "Quantity of groundwater within aquifers" The methodology received by the UN for "Quantity of groundwater within aquifers" required a baseline (average reference period of five years) in meters per hydrogeological region. This indicator is again domesticated for South Africa and based on the 40-60 percentiles of groundwater levels per hydrogeological region. There are a number of future indicators that can be included for aquifers under SDG 6.6, but the groundwater sector needs to come together and decide what is important to report on. These SDG targets reporting has given the Water and Sanitation sector a new look at data. It has forced us to critically think of concepts such as baseline and performance monitoring. We now know where our data gaps and targets are, and we have to provide an action plan to address these.
Ensuring the provision of sustainable water services in water-scarce humanitarian environments	F	Ward	2023	Water scarcity, Groundwater, Climate change, assessments, Monitoring, system strengthening, Resilience
Abstract Annually, UNICEF spends approximately US$1B in water, sanitation and hygiene programming (WASH), approximately half of which is spent in humanitarian contexts. In emergencies, UNICEF supports the delivery of water, sanitation and hygiene programming under very difficult programming contexts – interruptions to access, power supply and a lack of reliable data. Many of these humanitarian situations are in contexts where water scarcity is prevalent and where the demand and competition for water are increasing, contributing to tension between and within communities. While water scarcity is not new to many of these water-scarce areas, climate change is compounding the already grave challenges related to ensuring access to safe and sustainable water services, changing recharge patterns, destroying water systems and increasing water demand. Incorrectly designed and implemented water systems can contribute to conflict, tension, and migration. Ensuring a comprehensive approach to water security and resilient WASH services can reduce the potential for conflict and use water as a channel for peace and community resilience. This presents an enormous opportunity for both humanitarian and development stakeholders to design water service programmes to ensure community resilience through a four-part approach: 1. Groundwater resource assessments 2. Sustainable yield assessments (taking into consideration future conditions) 3. Climate risk assessments 4. Groundwater monitoring/early warning systems UNICEF promotes this approach across its WASH programming and the sector through technical briefs, support and capacity building.
Hydraulic Fracturing Of Coal Bed Methane In The Springbok Flats	Gerrit	van Tonder	2015
Abstract It is estimated that the three coal layers in the Springbok Flats contain about 5 TCF of coal bed methane (CBM). Two sedimentary basins, namely the southern Tuinplaas basin and the northern Roedtan basin, exist with coal layers with a total thickness of 7m which occurs mainly in three mayor seams. The coal layers are located between 20 m to more than 600m. Farmers in the Flats are concerned about the environmental impact of fracking the coal beds. They are mostly worried about the risk of groundwater pollution; the drawdown of the water table and the producing of a bad quality water during the mining process. They set up an EPA for the Springbok Flats in 2010 and until now, they have stopped more than 6 companies to conducted exploration (stopped strictly on account of the different laws in SA that were not adhered too). On average, 1000 liters of water is produced for every 2000 cubic feet coal bed methane mined in the USA. The quality of the produced water is not good (with typical Na values of more than 5 000 mg/l) and cannot be used for irrigation purposes. It is thus expected that about 500 million m3 of bad quality water will be produced for every 1 TCF mined in the Flats. This groundwater will be removed from the system and it is expected that a drawdown of up to 30m will be evident at places in the Springbok Flats. There are also a large number of dykes and faults in the Flats which imply that the upward movement of methane and water will be very probable after abandonment of each coal methane well.
The Utilisation Of Hydro-Geophysical Methods For Soil Moisture Measurements To Optimise Irrigation Management	Christian	Steyn	2019	soil moisture, Irrigation, flow
Abstract Precision agriculture continuously seeks improved methods to enhance productivity whether it is for greater crop yields or economic viability regarding labour inputs and satisfying the demand in a shorter time span. Soil moisture is one important factor that drives the agricultural industry and is therefore of utmost importance to manage it correctly. A shortage of water may result in reductions in yield, while excess irrigation water is a waste of water resources and can also have a negative impact on plant growth. Knowledge of the spatial distribution of soil moisture is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Electromagnetic induction, Frequency Domain Reflectometry, Neutron Scattering and conventional soil sampling have been utilised to determine the spatial variability of soil moisture within a field. Emphasis has been placed on practicality and accuracy of all the methods. Electromagnetics have proven itself to be the primary method to determine soil moisture within the field by comparing the results of the volumetric soil water content present in the field together with a combination of various soil properties such as clay and silt content, sand fraction, concretions, density and soil depth that contribute towards the accumulation of soil water. Electromagnetic induction has the highest resolution of data collected for a specific time period of all considered methods making it economically the best option for soil moisture management within a variable rate irrigation system. Electromagnetic induction has proven to be successful in delineating a field into management zones consisting of different classes based on observed conductivity values. Higher conductive zones are considered with small water demand. Lower conductive zones are considered with a greater water demand through a variable rate irrigation system. These water management zone maps could be informative for modelling, experimental design, sensor placement and targeted zone management strategies in soil science, hydrogeology, hydrology, and agricultural applications.
Investigating the influence of fine ash leaching in a tailings dam on the underlying aquifers	Paul JH	Lourens	2015	primary aquifers
Abstract Groundwater in South Africa is the most important source of potable water for rural communities, farms and towns. Supplying sufficient water to communities in South Africa becomes a difficult task. This is especially true in the semi-arid and arid central regions of South Africa where surface water resources are limited or absent and the communities are only depended on groundwater resources. Due to a growing population, surface water resources are almost entirely being exploited to their limits. These factors, therefore, increases the demand for groundwater resources and a more efficient management plan for water usage. For these reasons, the relation between the geology and geohydrology of South Africa becomes an important tool in locating groundwater resources that can provide sustainable quantities of water for South Africans. It was therefore decided to compile a document that provides valuable geohydrological information on the geological formations of the whole of South Africa. The information was gathered by means of interviews with experienced South African geohydrologists and reviewing of reports and articles of geohydrological studies. After gathering the relevant information, each major geological unit of South Africa together with its geohydrological characteristics was discussed separately. These characteristics include rock/aquifer parameters and behaviour, aquifer types (primary of secondary), groundwater quality, borehole yields and expected striking depths, and geological target features and the geophysical method used to locate these targets. Due to the fact that 90 % of South Africa's aquifers are classified as secondary aquifer systems, groundwater occurrence within the rocks of South Africa is mainly controlled by secondary fractures systems; therefore, understanding the geology and geological processes (faulting, folding, intrusive dyke/sills & weathering) responsible for their development and how they relate is important. However, the primary aquifers of South Africa (Coastal Cenozoic Deposits) should not be neglected as these aquifers can produce significant amounts of groundwater, such as the aquifer units of the Sandveld Group, Western Cape Province. Drilling success rates and possibility of striking higher yielding boreholes can be improved dramatically when an evaluation of the structural geology and geohydrological conditions of an area together with a suitable geophysical method is applied. The ability to locate groundwater has been originally considered (even today) a heavenly gift and can be dated back to the Biblical story of Moses striking the rock to get water: "behold, I will stand there before thee there upon the rocks thou shalt smite the rock and there shall come water out of it" (Exodus 17:6).
Use Of Environmental Isotopes To Determine Hydraulic Connectivity Across The Surrounding Aquifers At Majuba UCG	Gundo	Mathoho	2015
Abstract Environmental isotope techniques have been successfully applied in the field of hydrogeology over the last couple of decades and have proved useful for understanding groundwater systems. This paper describes a study of the environmental isotopes for Oxygen (18O) and Hydrogen (1H, 2H-Deutrium, 3H-Tritium) obtained from various points in and around the underground coal gasification (UCG) site in Majuba, South Africa. UCG is an alternative mining method, targeting deep coal seams that are regarded as uneconomical to mine. The process extracts the energy by gasifying the coal in-situ to produce a synthetic gas that can be used for various applications. The site consists of shallow, intermediate and deep aquifer systems at a depth of 70m, 180 and 300m respectively. The intermediate aquifer is further divided into the upper and lower aquifer systems. Samples were taken from each aquifer system together with supplementary samples from the Witbankspruit and an on-site water storage dam. A total of 15 samples were submitted for isotope analyses. By investigating the various isotopic signatures from all the samples taken, it will be possible to determine if there are similar or contrasting isotopic compositions by deducing possible water source for each sample due to isotopic fractionation caused by physical, chemical and biological processes. This will also be supported by deducing the mean residence time (MRT) for each water source sampled based on the Tritium data as well as the chemistry data already available for different sources. The chemistry data established linkages between the upper and lower intermediate aquifers.{List only- not presented} Key words: Environmental isotopes, UCG, Water source, Isotope fractionation
Units for joint management of cross-border groundwater impacts in Transboundary Aquifers: An overview of concepts and methodologies	C	Morales	2023	cross-border groundwater impacts, hotspots identification, joint management units, time and space scales factor, transboundary aquifers, zoning
Abstract This study aims to contribute to the conceptual and methodological development of units of joint management in transboundary aquifers (TBAs) to prevent and mitigate cross-border groundwater impacts (GWIs) in quantity and/or quality. Joint management units are a relatively new but growing topic in the field of TBAs, and their conceptualisation and appropriate identification are still at an early stage. By reviewing the literature on the subject and elaborating on its terminology, main features, and current methodological progress, a comparison of the existing methodologies for identifying such units is analysed. On this basis, trends and recommendations for further research and application of such methodologies to the joint management of TBAs are presented. The literature on this issue is scarce and has been published mainly in the last five years. These publications lack consistency in the use of concepts and terminology. The above has led to miscommunication and semantic issues in the concept behind such units and in comprehending the particular challenges of identifying them. Still, some directions and methodologies for identifying or directly delineating these management units have been proposed in the literature. However, no analysis from these methodological attempts has been conducted; thus, there are no lessons to be learned about this progress. This research looks forward to closing these gaps and making headway toward dealing with cross-border GWIs in TBAs, thus helping countries meet international law responsibilities and maintaining stable relationships among them.
A fresh look at the National Water Balance	Andries	Wilke	2015
Abstract The national water balance is primarily based on the availability of surface water and the historic allocation thereof. The changes that are required the next 20 years to ensure sustainable development of the nation will be painful, but is unfortunately at present not part of the public discussion, it is essentially ignored in favour of more "popular water topics".This paper intends to look at a few core aspects, they include the current water allocation in the national water balance, the relative value of the utilisation, the position of groundwater resources in changing the current relative allocation and the current groundwater utilisation. The paper further intends to be a less formal presentation of these aspects with the required data, references and conclusions available for distribution afterwards.
Advances In The Realm Of Hydrogeophysics: The Emerging Role Of Quantum Geoelectrophysics (Qgep) In Deeper Aquifer Exploration	R	Hatala	2017	Deep aquifers, Geophysics, QDMI, QGEP, Electromagnetics, ERT
Abstract Water is integral to our economy, the health of our environment, and our survival as a species. Much of this water is accessed from surface sources, mostly rivers, which are now under increased threat due to over use and the resulting hydro-political forces. Yet, groundwater exists as a viable option in many countries facing these mounting challenges. Knowledge of our deeper groundwater systems, although increasing, is still quite limited due to our propensity to focus efforts in the lower cost, lower risk, near- surface environment. However, accessibility to shallower groundwater is tightening due to increasing use, changing regulatory requirements, and climate change. The use of classical geophysics to explore for groundwater resources, such as seismic, gravity, magnetics, and resistivity, has been the industry standard for many decades. These technologies have proven quite effective both in the shallow and medium depth environments. However, newer remote sensing and ground-based technologies are now emerging with the ability to significantly reduce costs and time, and increase success for groundwater exploration and development programs. Quantum Direct Matter Indicator (QDMI) technologies, or applied methods of Quantum Geoelectrophysics (QGEP), are poised to enhance the hydrogeophysical industry, much like electro-magnetic (EM) and electrical resistivity tomography (ERT) did years ago. QDMI utilizes resonant frequency remote and direct sensing technologies that detect perturbations in the earth’s natural electric, magnetic and electromagnetic fields. Controlled source electromagnetic pulse methods with electromagnetic spectrum spectroscopy are used to identify aquifers, including thickness, water quality (fresh or saline) and temperature, to depths of 1000 m or more accurately. With multiple successes around the world, the deployment of this inventive and effective approach to groundwater exploration is poised to advance exploration geophysics globally.
Groundwater Protection Zoning- A case study of the Rawsonville research site.	Shuaib	Dustay	2015	groundwater protection zones
Abstract Currently limited progress is made in South Africa (and Africa) on the protection of groundwater used for drinking water. To achieve the objective of water for growth and development and to provide socio-economic and environmental benefits of communities using groundwater, significant aquifers and well fields must be adequately protected. Groundwater protection zoning is seen as an important step in this regard. Till today, limited case studies of groundwater protection zoning exists in Africa. A case study at the Rawsonville research site is conducted in this research project. Generic protection zones can be delineated at the site using published reports and database data. However, due to the complexity of the fractured rock at the research site, these would be of limited value and would not provide adequate protection for the well field Baseline data was collected by conducting a hydro census and through aquifer tests. An inventory of the activities that can potentially impact water quality was done and aquifer characteristics such as transmissivity and hydraulic conductivity were determined through various types of aquifer testing. Fracture positions were identified using fluid logging and fracture flow rates were also measured using fluid logging data. A conceptual model and preliminary 3D numerical model were created to try to understand groundwater movement at the research site. The knowledge gained will be used to guide information gathering and monitoring that can be used to build a more detailed numerical model and implement a trustworthy groundwater protection plan at a later stage. The expected results will have applicability to groundwater management in general. The protection plan developed during this project can be used as a case study to update and improve policy implementation. {List only- not presented}
Exploring The Potential Of The GRACE Derived Groundwater Drought Index (GGDI) To Forecast Groundwater Drought In South Africa	Kopano	Mokoena	2019	GRACE, Drought
Abstract Water has been recognized and acknowledged as a fundamental natural resource that sustains environmental diversity, social and economic development (Liu et al., 2017; Fisher et al., 2017). With increasing populations, climate change and limited monitoring networks for both ground and surface water, freshwater resources are becoming difficult to assess due to rapid changes in water supply and uses. Several efforts have been devoted towards the monitoring and management of water resources and discovery of alternative sources of freshwater. One of the more recent efforts is using gravity information to track changes in water storage on the earth's surface. The Gravity Recovery and Climate Experiment (GRACE) mission (https://www.nasa.gov/mission_pages/Grace/index.html) holds great potential for assessing our water resources in areas with little monitoring data. The increasing interest in the use of GRACE as a water resource information and monitoring tool, is due to its cost effectiveness and user-friendly system which affords a broad understanding of the world we live in and its processes, specifically in water resource management and hydrological modelling. South Africa's National Water Act (NWA) of 1998 highlights the importance of the sustainable development of water resources. However, it is difficult to sustainably manage South Africa's groundwater resources due to the difficultly in measuring and understanding our complex aquifers. The challenges in establishing sustainable monitoring of groundwater resources and its Reserve, are due to insufficient knowledge about the contribution that groundwater makes to surface water, and methods which reliably monitor groundwater resources. The GRACE is a joint satellite mission by the Deutschen Zentrum fur Luftund Raumfahrt (DLR) in Germany and the United States National Aeronautics and Space Administration (NASA). The satellite was launched on 17 March 2002 and provides monthly temporal differences of earth's gravity field and its mean gravity field (Schmidt et al., 2008). It can afford insights into the location of groundwater resources, and their changes. GRACE can however, only determine the change in total water storage and therefore information on other components of the water balance are required to isolate the groundwater component. Therefore, the integrated Pitman Model is ideal to be applied together with GRACE and the Model can isolate surface water, soil moisture and groundwater into various components. Many studies have evaluated GRACE-derived groundwater storage changes as a response to drought (Famiglietti et al. 2011; Scanlon et al., 2012), while Thomas et al. (2017b) evaluated a groundwater drought index based on GRACE observations in an effort to understand and identify groundwater drought. Typically, GRACE is applied at scales of 150 000 km2, however Thomas et al., (2017) has developed a recent method that allows for the application of his GRACE derived Groundwater Drought Index (GGDI) at smaller scales. This study applies Thomas et al. 2017 GGDI in South Africa to the Crocodile, Sedgefield and Doring catchments, in hopes to to evaluate drought characterisation using data from GRACE satellites, focusing on the total water storage deficits to characterise groundwater drought occurrence.
#GWD: The use of social media for science communication	Tercia	Strydom	2015
Abstract For a long time, professionals regarded social media as a superficial, unprofessional platform where internet users would submerge themselves in a virtual world, detached from real-life issues. Slowly, the myths and stigmas surrounding the use of social media has faded as more and more professionals and scientists have realized that these social platforms could be positively exploited in a professional manner which could be beneficial. In a digital age where information at our fingertips is the norm, professionals should co-evolve and ensure that their work is just as accessible and appealing, without the unnecessary jargon. Currently, science is mostly restricted to a very particular audience and conveyed in one direction only. Using a social media platform such as Twitter-which limits messages to only 140 characters-challenges scientists to convey their work in a very concise manner using simpler terminology. Furthermore, it dismisses the usual one-way form of communication by opening dialogue with fellow Twitter users. At conferences, Twitter can serve as a useful tool for active engagement which will not only "break the ice" between delegates but also ensure that important information is communicated to a much wider audience than only those in attendance. This idea was tested at the 2014 Savanna Science Network Meeting held in Skukuza, Kruger National Park, where the hashtag #SSNM was used. More than 63% of the Twitter users who participated in the #SSNM hashtag were actually not present at the conference. These external "delegates" were interested individuals from five different continents and in different professions besides Science. This highlights how social media can be exploited at conferences to ensure that key messages are conveyed beyond the immediate audience at the event.
Depth Discrete Multilevel Monitoring In Fractured Rock: State Of The Technology And Implications	John A	Cherry	2017	Monitoring, fractured rock, Hydrochemistry, MLS technologies
Abstract Well-established engineered systems for depth-discrete monitoring in fractured rock boreholes (referred to as a Multilevel System or MLS) are commercially available and offer much diversity in design options, however, they are used infrequently in professional practice and have seen minimal use in groundwater research. MLSs provide information about hydraulic head and hydrochemistry from many different depths in a single borehole and, therefore, magnify greatly the knowledge value of each borehole. Conventional practice globally is devoted to standard monitoring wells, either alone as longer single screened wells or in clusters or nests with a few wells screened at different depth intervals. These are the mainstay of the groundwater science and engineering community and severely limit prospects for each borehole to provide the information needed to solve the complex problems typically posed by fractured rock. This paper outlines the nature and evolution of MLS technologies and points to recent literature showing how MLSs add important insights that cannot be obtained using conventional wells. Also, it reviews commercially available MLS technologies, which present a range of robust options with each system having different characteristics and niches depending on characterization and monitoring goals and site conditions. The paper also describes refined MLS criteria aimed at improving the cost effectiveness and expanding capabilities of MLSs, so as to improve their accessibility for high resolution data acquisition in the context of both groundwater system characterization and long-term monitoring.
Blast curtain optimized with a numerical model for TSF seepage control	Robel	Gebrekristos	2015
Abstract Preventing the spread of seepage from tailings storage facilities (TSF's) in groundwater is necessary as it often contains toxic contaminants. Experience has shown that seepage from TSFs is inevitable and that zero seepage remains difficult even with complex liner systems. Multiple seepage control methods are often required to minimise seepage to ensure that environmental regulations are met. Control methods can be grouped into either barrier or collection systems. Barrier systems are used to hinder seepage whereas collection systems are used to intercept seepage. A blast curtain, which is the focus of this article, is a type of collection system that is still at a conceptual level but has seen little or no application worldwide. It works in principle, similarly to a curtain drain, but is typically extended to greater depths depending on the aquifer vulnerability. Numerical modeling has shown that this mitigation measure could add another line of defence for seepage control. The depth and effectiveness of the curtain can be optimized with a numerical model to ensure optimal interception of contaminated seepage around the TSF. Depths of up to 30 m in fractured aquifers have been simulated in this study. A blast curtain is constructed by drilling a set of boreholes around a TSF in close proximity to one another and then fracturing the rock using either explosives or fracking methods to create a more permeable zone. This is then combined with a series of scavenger wells or natural seepage to abstract the contaminated water. Numerical simulation has shown that blast curtains are effective especially if groundwater flow is horizontal. The effectiveness decreases if the vertical flow component is significant. A blast curtain can result in the lowering of the water table, however, local depression is a less of a concern than potential groundwater contamination. {List only- not presented}
High Resolution Site Characterisation (HRSC) In South Africa: Challenges, Successes And Lessons Learned	Samuel D	Mohr	2015
Abstract Inadequate characterization of contaminated sites often leads to the development of poorly constructed conceptual site models and consequently, the design and implementation of inappropriate risk management strategies. As a result, the required remedial objectives are not achieved or are inefficient in addressing the identified risks. Unfortunately, it is all too common to find remedial intervention strategies that run for lengthy periods of time at great cost while generating little environmental benefit due to inadequate characterization of site conditions. High resolution site characterization (HRSC) can provide the necessary level of information to allow for development of rigorous conceptual site models, which can be used to develop and implement appropriate risk management solutions for environmental problems. At the outset, the HRSC approach generally has comparatively higher costs than traditional state-of-the-practice assessment methods. However, the project lifecycle costs can be substantially reduced due to development of optimal risk management strategies. In developing countries where there is a lack of legislation relating to soil and groundwater contamination or, a lack of enforcement of legislation which is present, the long-term liabilities related to contaminated sites are often not immediately apparent to the parties responsible for the sites. This often creates a reticence to employ HRSC techniques due to their increased cost, especially when much of the technology must be imported on a project specific basis from either Europe or the United States. The Authors provide information from several case studies conducted in South Africa where HRSC techniques have been employed to gain a greater understanding of subsurface conditions. Techniques employed have included surface-based geophysical techniques such as electrical resistivity tomography (ERT) and multi-channel analysis of seismic waves (MASW), passive soil gas surveys, deployment of Flexible Underground Technologies (FLUTe?) liners, diamond core drilling, fluid electrical conductivity profiling, downhole geophysical logging tools, the Waterloo Advanced Profiling System (APS), and the use of field laboratories. Several of the techniques required importing equipment and personnel from Europe or the US, and in several case studies, were a first to be employed in South Africa, or the continent of Africa for that matter. The Authors present data obtained using the HRSC techniques from the case studies and elaborate on how the information obtained was used to drive effective decision making in terms of managing long term environmental risks at the various sites, which has been positively embraced by local clients. The authors also highlight key challenges in conducting HRSC investigations in an emerging market context.
Fly Ash Leaching Dynamics And Implication On Groundwater Contamination	Nadine	Swartz	2019	fly ash, contamination
Abstract South Africa utilizes coal for energy and chemical feedstock thereby generating millions of tons of ash every year. The ash is stockpiled in surface waste facilities where it poses a risk of leaching and contaminating groundwater. This study utilizes standard leaching tests, TLCP and SPLP, to evaluate and predict the mobility of different elements that leach from fly ash. Two different fly ash samples (Ash M and Ash T) were used in the study. A QEMSCAN analysis was also performed on the samples as well as the coal to determine the elementary and mineralogical compositions. Both Ash samples were generated from bituminous coals and had similar physical properties. Both ash samples were mixed respectively with the two different leachates one more acidic (Leachate A) the other more basic (Leachate B). Trace elements are present in ash in small amounts, but still at lower levels still pose threat to the environment and human health. Only three trace elements were found present in both ash samples. The detected trace elements in an increasing concentration order are: Manganese>Chromium>Copper. It appears the leaching behaviour of these trace elements is similar to the other metals, being insoluble at near neutral and alkaline pH range while dissolvable at low pH ranges. The results show that Leachate B was found to extract more material than Leachate A on a milligrams per gram of ash basis. The risk to groundwater contamination can be minimized by understanding the leaching dynamics and water retention of fly ash dumps as the results show.
A More Focused Approach To Developing Groundwater Resources In Rural Communities.	Nadene	Goosen	2019	Groundwater, rural communities, resources, Management
Abstract Water scarcity is a global challenge, particular in South Africa, which is a semi-arid country. Due to the continuing drought, appropriate groundwater management is of great importance. The use of groundwater has increased significantly over the years and has become a much more prominent augmentation component to the supply chain especially in rural communities. However, the approach used to develop groundwater resources, specifically in rural areas, can be improved in numinous ways to ensure drilling of successful boreholes that could meet water demands. A recent study done in the Thaba Nchu area focused on an adapted approach, which resulted in drilling successful boreholes that would be able to sustain their augmentation role in the long term. The adapted approach involves (i) a hydro-census that includes local knowledge and focused field observations, (ii) study of aerial photographs and geological maps on a regional scale, rather than on a village scale area, (iii) an optimised geophysical investigation to identify and map geological structures to drill production boreholes, (iv) conducting aquifer pump test to determine an optimum sustainable yield, (v) collecting water samples to determine if water quality is suitable for its specific use (vi) providing a monitoring program and abstraction schedule for each borehole. The adapted approach highlights the following improvements: (i) drilling of new production boreholes during times of bounty to allow for better time management on the project; (ii) including an experienced geohydrologist during planning phases, (iii) including a social component focussing on educating local communities on the importance of groundwater and introducing them to the concept of citizen's science, (iv) establishing a communication channel through which villagers can report any mechanical, electrical, quantity or quality issues for timeous intervention. Through applying these small changes to established components of development of groundwater resources, budgets and time management were optimised and additional communities could be added to the project without additional costs. This approach not only emphasised ways to improve the awareness and potential of groundwater resources, but also affects the economical-, social- and environmental welfare in rural communities.
Platinum mines will leave behind a sustainable legacy which will form a vital building block to meet future water demands	Fanie	Botha	2015	aeration and aerobic storage facilities, Nitrate
Abstract Slightly more out of the box idea is the use of anthropogenic aquifers as storage and chemical conditioners. This concept was first introduce by Eland Platinum Mine(EPM) and reported on in previous papers. At EPM water is used through a serious of natural aeration and aerobic storage facilities to reduce nitrate levels. In 2013 another group introduced pilot studies by virtue of abstraction in support of the water conservation and demand management strategy; which has proven that it could enable the operations to overcome water shortage periods and reduce pressure on Rand Water (RW). The pilot sites would deliver water into the dirty water circuit, but within five to ten years it may further be used to overcome months with zero potable water supply. . In platinum mines the more the aquifers are used the cleaner the water becomes, simply because introduced pollutants are not constant sources and country rock is mostly inert. In the future these aquifers have the potential to become larger storage facilities protected from floods and limited evaporation losses. It is foreseen that some of the mines in the western belt may have more water stored in primary aquifers than water stored within major water dams. Yields from these aquifers for individual aquifers may be up to 450 m3/hour and storage of 18 Mm3. . Why then this paper if we are already using it? The issue is that the true value of these aquifers an only be unlocked when they are used as recharging aquifers and thereby actively storing dirty water within a dirty water aquifer. Once we are able to undertake this the positive environmental gains such of environmental overflows, condition dirty water, reduction of pollution and significant reduction of the use of potable water from RW. {List only- not presented}
Combined use of Environmental and Artificial Tracers to Characterise the Vadose Zone.	Yazeed	Van Wyk	2021	Poster, vadose zone, isotopic tracers, recharge mechanisms, Protection, aquifer protection
Abstract Approximately 982 km3 /annum of the world’s groundwater reserve is abstracted, providing almost half of all drinking water worldwide. Globally, 70% is used for agricultural purposes while 38% for irrigation. Most water resources of South Africa are threatened by contamination caused by industrial, agricultural, and commercial activities, and many parts of the country face ongoing drought with an urgent need to find alternative freshwater sources, such as groundwater. Groundwater constitutes approximately 15% of the total volume consumed, hence it is an important resource that supplements insufficient surface water supplies across South Africa. Very little attention has been afforded to understanding the anthropogenically altered vadose zone as a potential source or buffer to groundwater contamination. This is evident from few research studies that has applied multiple isotopic tracers to characterise this zone. Most subsurface systems in South Africa are characterised by fractures, whereby flow and transport are concentrated along preferential flow paths. This study aims to evaluate the performance of different tracer classes (environmental and artificial) with one another, and create a better understanding of the hydraulic properties, mean residence time and transport mechanisms of these tracers. The influence of unsaturated zone thickness on recharge mechanisms will also be evaluated. Site visits will be conducted for the proposed study areas, and the neighbouring sources of contamination will be assessed. The matric potential and unsaturated hydraulic conductivities will be measured using various techniques. Water samples will be collected and analysed for the various tracers from the vadose zone using gravity lysimeters including suction cups. Several tracers will also be injected into boreholes where samples will be collected to calculate tracer residence times (BTC’s) and further constrain the hydraulic properties of the vadose zone. All samples will be analysed, interpreted, and simulated using the numerical finite-element modelling code SPRING, developed by delta h. The software derives quantitative results for groundwater flow and transport problems in the saturated and unsaturated zones of an aquifer. The research is expected to provide more insight into the selection and use of environmental and artificial tracers as markers for detecting, understanding the transport processes and pathways of contaminants in typical altered South African subsurface environments. The impact derived improved characterisation of the pathways, transport, and migration processes of contaminants, leading to groundwater protection strategies and appropriate conceptual and numerical models. The output from this study will determine the vertical and horizontal flux for both saturated and unsaturated conditions.
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.
Monitored Natural Attenuation on-sites with different geological setting	Bongani	Masombuka	2015
Abstract When considering how to reduce contamination of petroleum hydrocarbons in shallow aquifers, it is important to recognize the considerable capacity of natural processes continuously at work within the secondary sources of contamination. This natural processes are technically referred to as Monitored Natural Attenuation (MNA), a process whereby petroleum hydrocarbons are deteriorated naturally by microbes. This approach of petroleum hydrocarbon degradation relies on microbes which utilise oxygen under aerobic processes and progressively utilises other constituents (sulphates, nitrates, iron and manganese) under anaerobic processes. MNA process is mostly evident when light non-aqueous phase liquids (LNAPLs) has been removed while the dissolved phase hydrocarbon compounds are prominent in the saturated zone. The case studies aim at determining feasibility and sustainability of Monitored Natural Attenuation process at different sites with varying geological setting.
Groundwater Assessment using Borehole Magnetic Resonance	Benjamin	Birt	2019	magnetic resonance
Abstract Hydraulic behaviour of an aquifer is defined in terms of the volumes of water present, both producible and not (specific yield and specific retention), and the productivity of the water (hydraulic conductivity). These parameters are typically evaluated using pumping tests, which provide zonal average properties, or more rarely on core samples, which provide discrete point measurements. Both methods can be costly and time-consuming, potentially limiting the amount of characterisation that can be conducted on a given project, and a significant measurement scale difference exists between the two. Borehole magnetic resonance has been applied in the oil and gas industry for the evaluation of bound and free fluid volumes, analogous to specific retention and specific yield, and permeability, analogous to hydraulic conductivity, for over twenty years. These quantities are evaluated continuously, allowing for cost-effective characterisation, and at a measurement scale that is intermediate between that of core and pumping tests, providing a convenient framework for the integration of all measurements. The role of borehole magnetic resonance measurements in hydrogeological characterisation is illustrated as part of a larger hydrogeological study of aquifer modeling. Borehole magnetic resonance has been used for aquifer and aquitard identification, and to provide continuous estimates of hydraulic properties. These results have been compared and reconciled with pumping test and core data, considering the scale differences between measurements. Finally, an integrated hydrogeological description of the target rock units has been developed.
Characterisation And Protection Of Deep Aquifers In South Africa: Consolidation Of Data Sources	Francois D	Fourie	2017	Deep aquifers, data sources
Abstract This paper describes the results of study aimed at consolidating the available data sources on deep aquifers and deep groundwater conditions in South Africa. The study formed part of the larger WRC Project K5/2434 (Characterisation and Protection of Potential Deep Aquifers in South Africa). Since very little is known about the aquifer conditions below depths of 300 m, all groundwater information from depths greater than 300 m was considered to represent the deep aquifer systems. Various confirmed and potential sources of data on deep aquifers and groundwater conditions were identified and interrogated during this study, namely: 1. Boreholes of the International Heat Flow Commission (IHFC). The IHFC database indicates the location of 39 deep boreholes ranging in depth from 300 to 800 m, with an average depth of 535 m. 2. The Pangea database of the International Council for Science (ICSU). The Pangea database has information on 119 boreholes in South Africa, of which 116 are deeper than 300 m. 3. A database on deep boreholes at the Council for Geoscience (CGS). This database contains information on 5 221 boreholes with depths exceeding 300 m. 4. Information on the deep SOEKOR boreholes drilled during the 1960s and 1970s (at least 38 boreholes). 5. Information on deep boreholes from the database of the Petroleum Agency SA. 6. The National Groundwater Archive (NGA) of the Department of Water and Sanitation (DWS). 7. Information derived from the thermal springs in South Africa. 8. Boreholes drilled as part of the Karoo Research Initiative (KARIN). 9. Information on the locations and depths of underground mines in South Africa. Information on the occurrence of deep groundwater could potentially be obtained from these mines. The study shows that, although information on a vast number of deep groundwater sites is listed in the various databases, the data relevant to the geohydrological conditions are scant at most sites. This paucity of geohydrological data implies that the deep aquifers of South Africa are currently poorly understood.
Packer Testing and Analytical Modelling For Groundwater Inflow Estimation for Proposed Shafts	Robel	Gebrekristos	2015
Abstract Two ventilation shafts were proposed to be excavated to depths of 100 and 350 m to intersect an underground mine, in the Bushveld Complex. The area is made up of fractured aquifers and the assignment was to identify the exact positions of the permeable zones within the shafts profiles as well as estimate the groundwater inflow rates at every 5 m interval along the shafts profiles. The project was budget and time constrained and therefore the preferred hydrogeological characterisation techniques, particularly the percussion drilling, aquifer testing and numerical modelling could not be conducted. The study was completed by conducting packer tests in HQ sized holes drilled at the exact positions of the proposed shafts. The packer test data was then interpreted using Thiem equation, a modification of Darcy Equation for radial flow, to estimate the steady state inflow rates into the shafts. Transient state flow is more challenging to calculate analytically, as it is time and aquifer storage dependent. However, transient state flow in shafts exists for the first 10 - 15 days only and is short lived. Thereafter, a steady state flow occurs where the rate is nearly fixed for the rest of the life of mine, unless new external stresses, such as mine dewatering, takes place within the radius of influence. Six months later the shafts were excavated and the permeable zones were encountered at the exact positions as predicted using the packer testing. In addition, the inflow rates calculated using analytical modelling was successful in estimating the inflow rates recorded after the shafts were excavated. The packer testing and analytical modelling was therefore effective in assisting the mine to plan the necessary pumps and management plans within the allocated budget and timeframe.
Change, Challenge And Opportunity – Some Reflections On Hydrogeology Education, The Sustainable Development Goals And Global Change	B	Misstear	2017	education, training, IAH, Strategic Overview papers, SDGs
Abstract This keynote paper addresses several issues central to the conference theme of “Change, Challenge and Opportunity”. For hydrogeologists to exert greater influence on groundwater management globally, proper education and training is essential. Universities play a key role in educating hydrogeologists in the fundamental principles of groundwater science through taught Masters and other degree programmes. Scientific associations such as the International Association of Hydrogeologists (IAH) also have an important part to play in education and training through short courses, conferences and mentoring schemes, and in enhancing groundwater science through journal and book publications and scientific commissions. IAH’s mission is to promote the wise use and protection of groundwater and, in this respect, a series of Strategic Overview papers have been prepared to inform professionals in other sectors of the interactions between groundwater and these sectors. Two of the Strategic Overview papers focus on the SDGs and global change, and some of the groundwater challenges in these areas are described. Whilst these challenges will provide hydrogeologists with opportunities to influence global water issues in the 21st century, hydrogeologists will need to be able to communicate effectively with all of the stakeholders, using traditional and more modern forms of communication, including social media.
A Study Of Interaction Between Groundwater And Surface Water Using Environmental Isotopes, Hydrochemistry And Feacal Coliform BA	Bongizenzo	Nyawo	2015
Abstract The Table Mountain Group (TMG) Formation in the Uitenhage region, in the Eastern Province of South Africa, has many groundwater users, which could result in the over-exploitation of the underlying aquifer. Consequently, several investigations have been conducted to help in the planning and management of groundwater resources within the region. Traditionally, these investigations have considered groundwater and surface water as separate entities, and have been investigated separately. Environmental isotopes, hydrochemistry and feacal colifom bacteria techniques have proved to be useful in the formulation of interrelationships and for the understanding of groundwater and surface water interaction. The field survey and sampling of the springs, Swartkops River and the surrounding boreholes in the Uitenhage area have been conducted. After full analysis of the study, it is anticipated that the data from the spring, Swartkops River and the surrounding boreholes show interannual variation in the isotope values, indicating large variation in the degree of mixing, as well as to determine the origin and circulation time of different water bodies. ?D and ?18O value for the spring ranges from ?18.9? to ?7.4?, and 5.25? to 4.82?, respectively, while ?D values for borehole samples range from ?23.5? to ?20.0? and ?18O values range from ?5.67? to ?5.06?. In the river sample, ?D values ranges from ?12.1? to ?4.2?, ?18O from ?3.7? to ?1.13?, respectively. The entrobacter aerogen and E.Coli bacteria were detected in the samples. E. coli population for spring and the artesian boreholes indicated low value while the shallow boreholes had higher values are relatively closer to those of the middle ridges of the Swartkops River. The EC values for the spring samples averages at 14 mS/m, borehole samples ranges from 21 mS/m to 1402 mS/m, and surface water ranges from 19 mS/m to 195 mS/m. Swartkops River is an ephemeral, therefore it is expected that diffuse recharge occurs into the shallow aquifer.
Teaching Machines Hydrogeology: Demonstrating The Use Of Machine Learning In Groundwater Science And Management	Rui	Hugman	2019	Machine learning, AI
Abstract The advent of the 'Big Data' age has fast tracked advances in automated data analytics, with significant breakthroughs in the application of artificial intelligence (AI). Machine learning (ML), a branch of AI, brings together statistics and computer science, enabling computers to learn how to complete given tasks without the need for explicit programming. ML algorithms learn to recognize and describe complex patterns and relationships in data - making them useful tools for prediction and data-driven discovery. The fields of environmental sciences, water resources and geosciences have seen a proliferation of the use of AI and ML techniques. Yet, despite practical and commercial successes, ML remains a niche field with many under-explored research opportunities in the hydrogeological sciences. Currently physical-process based models are widely applied for groundwater research and management, being the dominant tool for describing and understanding processes governing groundwater flow and transport. However, they are limited in terms of the high data requirements, costly development and run time. By comparison, ML algorithms are data-driven models that establish relationships between an input (e.g. climate data) and an output (e.g. groundwater level) without the need to understand the underlying physical process, making them most suitable for cases in which data is plentiful but the underlying processes are poorly understood. Combining data-driven and process-based models can provide opportunities to compensate for the limitations of each of these methodologies. We present applications of ML algorithms as knowledge discovery tools and explore the potential and limitations of ML to fill in data gaps and forecast groundwater levels based on climate data and predictions. Results represent the first step in on-going work applying ML as an additional tool in the study and management of groundwater resources, alongside and enhancing conventional techniques such as numerical modelling.
The Significance of Collecting Hydrogeological Data and Conceptualising the Groundwater System at the Exploration Stage of the Mine Life Cycle	Jacqueline	Stapelberg	2019	Poster, hydrogeological setting, mine life cycle, exploration drilling, piezometers, budget optimisation
Abstract The hydrogeological setting of a proposed mine site can significantly influence the viability of the mining venture. The management of groundwater inflows, costs of the dewatering technology, construction and maintenance of storage facilities, discharge strategies and anticipated environmental impacts are vital factors for consideration. It is fundamental to assess the hydrogeological setting at an early stage of the mine life cycle and should involve the collection of sufficient hydrogeological data, conceptualisation of the hydrogeological setting and an assessment of planned mine operations and anticipated impacts. Ambient hydrogeological conditions at the deposit area may be identified by conducting a hydrocensus and utilising existing ore exploration drilling data. Information from the hydrocensus and ore exploration drilling can provide valuable preliminary data on groundwater risks, dewatering and available groundwater resources. Potential groundwater/surface water interactions and receptors sensitive to environmental impacts can be identified during a hydrocensus. Similarly, water strikes and fracture density recorded during exploration drilling provide valuable insight to the subterranean environment. It is also possible to obtain aquifer hydraulic properties through packer testing of exploration boreholes. Geochemical test work on exploration borehole-cores could provide valuable information regarding contamination risks from ore deposit and waste material storage. The installation of piezometers within available and accessible exploration holes that extend below the regional groundwater level can pioneer the collection of monitoring data crucial for consideration during the mine life cycle and provide an understanding of the interaction between hydrogeological units and recharge characteristics. Ultimately, mine operations and associated potential impacts on the surrounding groundwater environment can be simulated with the application of numerical hydrogeological flow and contaminant transport models. The numerical models can simulate the regional groundwater flow system and complexities of the mine environment, the accuracy of which is influenced by the type, spatial and temporal distribution of the data collected. It is accordingly suggested that the collection of hydrogeological data and information during the exploration phase would facilitate the timely conceptualisation of potential groundwater risks and effective planning of hydrogeological investigations required during upcoming phases while assisting in the budget optimisation of these future studies.
A review of groundwater resource protection measures in South Africa	Eberhard	Braune	2015

Groundwater Sampling: Measurement Uncertainties And Their Implications For Decision Making	Modreck	Gomo	2019	sampling
Abstract The uncertainties associated with both the sampling process and laboratory analysis can contribute to the variability of the results. In most cases, it does appear that if the water samples have been analysed by an accredited laboratory, the results are acceptable. While the accreditation of analytical laboratory and therefore its credibility is very important to uphold quality and integrity, the same should be said about the sampling process. The quality and credibility of a sampling process is typically left to the responsibility of the appointed groundwater practitioner without any criteria to evaluate the quality and integrity of the sampling process. Perhaps the quality and integrity of the sampling process is evaluated based on trust or experience of the practitioner. However without any form of scientific criteria to evaluate the quality and integrity of the sampling process, it is difficult for the sampling process to be scrutinized. The quality and integrity of both the sampling process and laboratory analysis must be scientifically evaluated based on the uncertainty of measurements in line with the monitoring goals/requirements. This presentation discusses the aspects of evaluation of measurement uncertainties associated with groundwater sampling as an important component of quality assessment of groundwater sampling processes. The potential implications of the uncertainties on the final results and their use in decision making is also discussed. The credibility of the decisions made also depends on the knowledge about the uncertainties of the final results
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.
Ground Water Management in South Africa: Challenges and Constraints	Courage	Mlambo	2015
Abstract Water scarcity is a growing issue in South Africa. The consumption of water is rising and as such, water is becoming a scarce and valuable resource. Given the circumstances that South Africa is facing, improving the use of ground water could help tackle water scarcity in South Africa. Groundwater has been an important source of water and it can bring socio-economic benefits if properly used. Studies have proved that groundwater resources play a fundamental role in the security and sustainability of livelihoods and regional economies throughout the world. However, in South Africa, groundwater still remains a poorly managed resource and this hinders socio-economic development. This paper examines the current state of ground water management in South Africa. The paper also examines how ground water in South Africa is currently allocated and used, and explores some of the consequences of current water management arrangements. {List only- not presented}
A numerical simulation of solute transport in dry coal ash dumps with a case study in South Africa	Innocent	Muchingami	2015
Abstract An understanding of the movement of moisture fluxes in the unsaturated zone of waste disposal sites play a critical role in terms of potential groundwater contamination. Increasing attention is being given to the unsaturated or vadose zone where much of the subsurface contamination originates, passes through, or can be eliminated before it contaminates surface and subsurface water resources. As the transport of contaminants is closely linked with the water ?ux in through the unsaturated zone, any quantitative analysis of contaminant transport must ?rst evaluate water ?uxes into and through the this region. Mathematical models have often been used as critical tools for the optimal quantification of site-speci?c subsurface water ?ow and solute transport processes so as to enable the implementation of management practices that minimize both surface and groundwater pollution. For instance, numerical models have been used in the simulation of water and solute movement in the subsurface for a variety of applications, including the characterization of unsaturated zone solute transport in waste disposal sites and landfills. In this study, HYDRUS 2D numerical simulation was used to simulate water and salt movement in the unsaturated zone at a dry coal ash disposal site in Mpumalanga, South Africa. The main objective of this work was to determine the flux dynamics within the unsaturated zone of the coal ash medium, so as to develop a conceptual model that explains solute transport through the unsaturated zone of the coal ash medium for a period of approximately 10 year intervals. Field experiments were carried out to determine the model input parameters and the initial conditions, through the determination of average moisture content, average bulk density and the saturated hydraulic conductivity of the medium. A two dimensional finite-element mesh of 100m x 45m model was used to represent cross section of the ash dump. Two dimensional time lapse models showing the migration of moisture fluxes and salt plumes were produced for the coal ash medium. An explanation on the variation of moisture content and cumulative fluxes in the ash dump was done with reference to preexisting ash dump data as well as the soil physical characteristics of the ash medium. {List only- not presented}
Groundwater and Surface Water Interaction Study for the Ingula Wetland	Christie	Terrell	2015
Abstract The Bedford Dam is the upper storage dam for the Ingula Pumped Storage Scheme and is situated in the Ingula/Bedford Wetland. This wetland has a high structural diversity which supports a unique assemblage of plants and invertebrates. The flow regulation and water purification value is of particular importance as the wetland falls within the Greater Vaal River catchment. Concern was raised with respect to the potential negative impact of the newly constructed dam on the dynamic water balance within the wetland. An assessment of the extent to which groundwater drives / sustains the wetland systems and the water requirements needed to sustain the wetland processes was determined. This includes establishing the impact of the Bedford Dam on the groundwater and wetland systems as well as providing recommendations on management and monitoring requirements. The hydropedological interpretations of the soils within the study area indicate that baseflow to the wetland is maintained through perennial groundwater, mainly recharged from infiltration on the plateau, and was confirmed through isotope sampling and hydrometric measurements. It is apparent that the surface flows in the main wetland are fed by recent sources, while the subsurface layers in the wetland are sustained by the slower moving near-surface and bedrock groundwater. The movement of groundwater towards the wetland is hindered by the numerous dykes creating a barrier to flow. Nevertheless, there seems to be a good connection between the groundwater sources in the upland and the surface drainage features that conduct this water to the contributing hillslopes adjacent to the main wetland. The surface flows of the main wetland are sustained by contributions from tributary fingers. The discharge out of the wetland is highly seasonal
Water Quality Guidelines: Which to use and where applicable?	Lerize	Van Wyk	2021	Poster, Water quality, guidelines, SAWQG, SANS, WHO, WUL
Abstract When conducting water quality monitoring, questions arise on which water quality guidelines to use and where to apply them. For example, the use of South African Water Quality Guidelines (SAWQG) for Domestic usage compared to the use of the South African National Standards (SANS) for Potable Water Quality when monitoring drinking water quality. The World Heath Organization (WHO) published a set of water quality guidelines for drinking water which can also be used instead of SANS. Using various water quality guidelines to assess water quality can give different outcomes on the state of water quality of a particular site. For example, SANS water quality guidelines are less strict when compared to the SAWQG target values, however, SAWQG are comprised of different sets of standards for different usages. SAWQG distinguish between drinking water, livestock and irrigation, aquatic systems and industrial usage while SANS are only used for potable or bottled water. The International Finance Corporation (IFC) that is part of the World Bank Group published the Environmental, Health, and Safety (EHS) Guidelines for Environmental Wastewater and Ambient Water Quality, guidelines set specifically for wastewater and ambient water quality. Utilizing this poster, I will explain when to use which guidelines with different types of water samples. I will also discuss the stringent water use license limits applied at some sites compared to the national standards of South Africa.
Integrated Modelling: A Tool For Urban Groundwater Management On The Cape Flats, Cape Town	Benjamin	Mauck	2015
Abstract There is growing concern that South Africa's urban centres are becoming increasingly vulnerable to water scarcity due to stressed surface water resources, rapid urbanisation, climate change and increasing demand for water. Given South Africa's water scarcity, global trends for sustainable development, and awareness around the issues of environmental degradation and climate change, there is a need to consider alternative water management strategies. Water Sensitive Urban Design (WSUD) is an approach to sustainable urban water management that attempts to achieve the goal of a 'Water Sensitive City'. The concept of a Water Sensitive City seeks to ensure the sustainable management of water using a range of approaches such as the reuse of water (stormwater and wastewater), exploiting alternative available sources of supply, sustainable stormwater management and improving the resource value of urban water through aesthetic and recreational appeal. Therefore, WSUD attempts to assign a resource value to all forms of water in the urban context, viz. stormwater, wastewater, potable water and groundwater. However, groundwater is often the least considered because it is a hidden resource, often overlooked as a form a water supply (potable and non-potable) and it is often poorly protected. The management of urban groundwater and understanding the impacts of WSUD on groundwater in South African cities is challenging, due to complex geology, ambiguous groundwater regulations and management, data limitations, and lack of capacity. Thus, there is a need for an approach to assess the feasibility of management strategies such as WSUD, so that the potential opportunities and impacts can be quantified and used to inform the decision making process. An integrated modelling approach, incorporating both surface and subsurface hydrological processes, allows various urban water management strategies to be tested due to the complete representation of the hydrological cycle. This integration is important as WSUD is used to manage surface water, but WSUD known to utilise groundwater as a means of treatment and storage. This paper assesses the application, calibration and testing of the integrated model, MIKE SHE, and examines the complexities and value of establishing an integrated groundwater and surface water model for urban applications in South Africa. The paper serves to demonstrate the value of the application of MIKE SHE and integrated modelling for urban applications in a South African context and to test the models performance in Cape Town's unique conditions, accounting for a semi-arid climate, complex land use, variable topography and data limitations. Furthermore, this paper illustrates the value of integrated modelling as a management tool for assessing the implementation of WSUD strategies on the Cape Flats, helping identifying potential impacts of WSUD interventions on groundwater and the potential opportunities for groundwater to contribute towards ensuring to Cape Town's water security into the future.
The connectedness of transboundary groundwater researchers: from network analysis to network-building	A	Fernald	2023	network analysis, network-of-networks, transboundary groundwater
Abstract The Transboundary Groundwater Resilience (TGR) Network-of-Networks project brings together researchers from multiple countries to address the challenges of groundwater scarcity and continuing depletion. Improving groundwater resilience through international research collaborations and engaging professionals from hydrology, social science, data science, and related fields is a crucial strategy enabling better decision-making at the transboundary level. As a component of the underlying data infrastructure, the TGR project applies visual analytics and graph-theoretical approaches to explore the international academic network of transboundary groundwater research. This enables the identification of research clusters around specific topic areas within transboundary groundwater research, understanding how the network evolved over the years, and finding partners with matching or complementary research interests. Novel online software for analysing co-authorship networks, built on the online SuAVE (Survey Analysis via Visual Exploration, suave.sdsc.edu) visual analytics platform, will be demonstrated. The application uses OpenAlex, a new open-access bibliographic data source, to extract publications that mention transboundary aquifers or transboundary groundwater and automatically tag them with groundwater-specific keywords and names of studied aquifers. The analytics platform includes a series of data views and maps to help the user view the entire academic landscape of transboundary groundwater research, compute network fragmentation characteristics, focus on individual clusters or authors, view individual researchers’ profiles and publications, and determine their centrality and network role using betweenness, eigenvector centrality, key player fragmentation, and other network measures. This information helps guide the project’s data-driven international networking, making it more comprehensive and efficient.