Philosophiae Doctor - PhD / Governance is essentially the process whereby organisations or networks of organisations exercise their authority. It describes how a body with authority makes or does not make decisions, and how it implements - or does not implement - those decisions. 'Good' groundwater governance can then be defined by how fair the decision-making process is, and how effective the implementation process is. Groundwater governance in South Africa is increasingly being categorized as ineffective. The purpose of this thesis is to explore ways to improve groundwater governance in South Africa. Initial reviews of international studies of groundwater governance did not find any processes that could be directly imported into the South African governance landscape for testing. The global consensus was that there were no blueprints for improving groundwater governance, and that each case should be treated as unique. Therefore the thesis had to change from its initial aim of finding firm rules that could be tested in the South African context, to a revised aim of formulating tentative heuristics, rules, strategies and hypotheses that might be useful for further work in the South African context.An exploratory, inductive-based, loosely structured methodology was therefore employed rather than a more formal, deductive-based testing of hypotheses. In short, the objective of this thesis was concerned with formulating hypotheses rather than testing them.The novel, general, contribution made by this thesis is to synthesize global groundwater governance literature with the specific aim of improving groundwater governance in a specific country. While reviews of global literature do exist, they have thus far only been used to make generic recommendations, and have not been specifically applied to a country. Conversely, while attempts to improve groundwater governance for specific regions and countries do exist, these attempts have largely done so without synthesizing existing global knowledge. Indeed, the emphasis on national, regional and local studies has principally been to understand the factors at work affecting groundwater governance, rather than to improve governance.

>Magister Scientiae - MSc / Crystalline basement aquifers are an important source of water supply in sub-Saharan Africa for various purposes. These aquifers are characterized by fractured rock networks which form pathways for groundwater recharge, flow, and discharge in subterranean groundwater areas. The fractured rock networks in these areas form fractured rock aquifers which in some cases are protected or reserved. In South Africa, various aquifers with these characteristics have been declared as subterranean groundwater control areas. The physical characteristics of these hydrogeological settings remains crucial in sustaining ecosystems and supporting socio-economic practices such as irrigation, among others. However, the role of fracture connectivity in crystalline basement aquifers remains poorly understood despite the well-established knowledge about the hydrogeological characteristics of such areas. / 2022

Dissertation Submitted to the University of the Witwatersrand in the Fulfilment of the Master’s Degree in Geology (Hydrogeology) Faculty of Science University of the Witwatersrand Date: May 2017 / The state of water quality in the Swartkops River catchment in the Uitenhage area, Eastern Cape Province, South Africa, continues to be degraded by anthropogenic activities, which include municipal waste water, industrial waste and agricultural runoff. The study area consists of two aquifers (Swartkops and Coega) that are separated by the fault (Coega fault). In the study area there are two main rivers, namely: Swartkops River and Coega River, which are situated in the Swartkops Aquifer and Coega Aquifer, respectively. Most of the degrading anthropogenic activities are situated in the vicinity of the Swartkops River. The focus of the study was on the pollution of the stream water and aquifer (groundwater), with particular emphasis on the groundwater management. The study objectives were to establish the relationship between groundwater levels and surface topography using Bayesian interpolation method and groundwater and surface water interaction using environmental isotope and hydrogeochemical techniques. The bacteriological assessment was also conducted to determine if hydraulic connections exist between groundwater and the polluted streams. The results of the Bayesian Interpolation Method indicated that there was a strong relationship between the groundwater level elevation and surface topography with the correlation coefficient of 0.9953. The results also indicated that the fault is permeable; hence it did not have influence on groundwater circulation; however, groundwater does not flow from Swartkops River to Coega Aquifer due to groundwater flow gradient. The environmental isotope results indicated that both Swartkops Aquifer and Swartkops River were characterised by heavy isotopes signatures, which indicated the correlation between the two water components. The results further showed that the Swartkops River was recharging the Swartkops aquifer. However, no correlation was established between Swartkops River and Coega aquifer due to flow gradient. Although the flow gradient allows the flow of groundwater from Coega Aquifer to Swartkops Aquifer, Coega aquifer is a Government Water Controlled Area, which could have a very low to none impact on the other aquifer. Piper diagram and stiff diagrams indicated one water type found in the Swartkops and Coega aquifers, which was: Na-Cl type. The water in the Coega aquifer indicated high salinity in the chemical properties, which was typical old marine water derived from deep groundwater source. It was noted that the electrical conductivity values in the Waste Water Treatment Work were closest to those of the Swartkops River and Aquifer, which was in central to those of Coega Aquifer. The bacterial analysis results indicated that during the wet season most of the bacterial counts were high as compared to dry season. It was noted; however, that during the wet season the bacterial counts appeared similar in both aquifers. It is unlikely that the similarities emanated from the interaction of the two aquifers as the analysis of the results indicated that the bacterial counts found in the Coega Aquifer emanated from the farming activities. The study concluded that the fault act as a pathway for migration of groundwater flow. It was established that the groundwater only flows from Coega Aquifer to Swartkops Aquifer due to difference in the hydraulic gradient. / MT 2017

Fluvial flooding has long been recognized as one of the most frequently occurring natural disasters worldwide, with consequences as large economic losses from damages on infrastructure and agriculture, as well as severe impacts on human health. A less known and explored type of flooding is groundwater flooding. A flood type that for instance can arise in river-connected floodplains when groundwater levels rise to the ground surface due to increased river stages in the watercourse. Although groundwater flooding in general is a poorly understood phenomenon, it has become more recognized since its inclusion in the European Floods Directive (2007/60/EC) in 2007. Sweden has however excluded pure groundwater flooding as a separate flood type in its interpretation of the directive, but recognizes groundwater as a component which together with soil water and river water can influence the appearance of a flood event. One of the difficulties regarding groundwater floods that occur in connection to a river is that they typically are hard to differentiate from inundations of fluvial or pluvial origin. It is however important to address the role of groundwater in the inundation of these settings, since traditional flood protection strategies like levees might be circumvented by flows through the subsurface. The aim of this study has been to investigate the role of groundwater in the flooding of a river-connected floodplain by setting up a groundwater model in the integrated hydrological modeling tool MIKE SHE and couple it to an existing MIKE 11 river model, developed by DHI. The study area is a floodplain located along the river Silverån, a tributary to the river Emån, located in the south eastern part of Sweden. By running the model using four different sub-scenarios, regarding initial groundwater level and amount of precipitation, flood extent and contribution of groundwater to the inundation, in relation to other flood sources, has been investigated for different river discharges. A scenario with artificial levees constructed along parts of the river was also examined as levees have been found to have little effect on groundwater floods. As the model provides a simplified and generalized representation of reality it possesses several uncertainties, and so does the results. In summary, the results are in line with what is stated in the Swedish interpretation of the European Floods directive. It has not been possible to demonstrate pure groundwater flooding, but the results suggest that an elevated groundwater level in the beginning of a flood event will increase the extent of the inundation and result in a larger contribution of groundwater to the total amount of flood water. This suggests that there, in some cases, might be a value in integrating groundwater processes in flood risk mapping. Something that is not included in the conventional hydraulic 1D and 2D models, which traditionally are used in flood mapping. As could be expected, the results indicate that groundwater only accounts for a minor part of the flood water added to the total floodplain, while the major sources are river water and surface runoff. A delimited floodplain section that was investigated more in detail, as an increased flow from groundwater to overland water was detected along it, did however show larger contributions from groundwater. This river reach was less vulnerable to fluvial flooding, which in total resulted in a less severe flood, but also enabled a larger amount of groundwater to seep up to the floodplain surface. These conditions did also result in that the river section experienced a worsened inundation at the sub-scenario of high precipitation and high initial groundwater level, as levees were constructed along the river. Most likely because a lot of surface runoff, otherwise able to drain to the river along this section, got trapped outside the levees since it was unable to drain both to the river and to the saturated ground. These results support the theory that levees have little impact on groundwater flooding and stresses the importance 0f surveying and understanding the governing processes in the inundation of a floodplain when planning which type of flood protection scheme to use. / Översvämning utmed vattendrag, så kallad fluvial översvämning, har länge varit känd som en av de vanligast förekommande naturkatastroftyperna världen över, med konsekvenser i form av stora ekonomiska förluster, skador på infrastruktur och jordbruk samt allvarlig påverkan på människors hälsa. En mindre känd och utforskad översvämningstyp är grundvattenöversvämning. En typ av översvämning som kan uppstå i svämplanet längs ett vattendrag då grundvattennivån går upp i markytan till följd av förhöjda nivåer i vattendraget. Trots att grundvattenöversvämning generellt sett är ett outforskat fenomen har det blivit mer uppmärksammat sedan det inkluderades i det europeiska översvämningsdirektivet (2007/60/EG) som antogs 2007. I Sverige har man dock valt att exkludera renodlade grundvattenöversvämningar ur sin tolkning av direktivet och sagt att sådana inte förekommer i Sverige. Istället ser man grundvattnet som en av delarna i ett samverkande system, där det tillsammans med markvatten och ytvatten kan ha påverkan då ett vattendrag översvämmas. En svårighet med grundvattenöversvämningar som inträffar i anslutning till vattendrag är att de kan vara svåra att skilja från översvämningar med fluvialt eller pluvialt ursprung. Det är dock viktigt att uppmärksamma grundvattnets roll i den här typen av översvämningar då traditionella åtgärder som sätts in mot översvämningar, såsom invallningar, kan kringgås av flöden genom marken. Syftet med den här studien har varit att undersöka grundvattnets roll vid en översvämning utmed ett vattendrag genom att konstruera en grundvattenmodell i det integrerade hydrologiska modellverktyget MIKE SHE och koppla denna till en befintlig MIKE 11 vattendragsmodell, utvecklad av DHI. Modellområdet som studerats är beläget längs Silverån, ett av biflödena till Emån i sydöstra Sverige. Genom att undersöka fyra olika delscenarion, avseende initial grundvattenyta och nederbördsmängd, har översvämningsutbredning samt grundvattnets bidrag till översvämningen utvärderats för olika vattenflöden. Ett scenario där invallningar konstruerats längs delar av vattendraget har också undersökts, eftersom invallningar visat sig ha begränsad effekt på grundvattenöversvämningar. Eftersom modellen utgör en förenklad och generaliserad representation av verkligheten har den flertalet osäkerheter, något som även gäller för modellresultaten. Sammanfattningsvis kan sägas att resultaten är i linje med den svenska tolkningen av det europeiska översvämningsdirektivet. Det har inte varit möjligt att påvisa renodlade grundvattenöversvämningar. Däremot pekar resultaten på att en förhöjd grundvattennivå under inledningen av ett översvämningstillfälle kommer att bidra till en ökad översvämningsutbredning, samt ett större bidrag av grundvatten till den totala mängden översvämningsvatten. Detta indikerar att det i vissa fall skulle kunna finnas en mening i att inkludera grundvattenprocesser vid översvämningskartering. Något som inte finns med i de konventionella hydrauliska 1D- och 2D-modeller som traditionellt används vid översvämningskarteringen. Som väntat visar resultaten på att grundvattnet står för en mycket liten del av det vatten som totalt översvämmar det undersökta svämplanet, och att de främsta källorna är vatten från vattendraget tillsammans med ytavrinning. Längs en avgränsad sträcka av svämplanet som undersöktes mer i detalj, då ett ökat flöde från grundvatten till vatten på markytan påträffades längs denna, återfanns dock ett större bidrag från grundvattnet. Denna del av svämplanet var mindre känsligt för fluvial översvämning, något som på det hela taget resulterade i en mindre allvarlig översvämning, men också tillät en större mängd grundvatten att tränga upp på markytan. Dessa förhållanden ledda också till att den aktuella delen av svämplanet kom att få en förvärrad översvämning då vallar konstruerades för delscenariot med hög nederbörd och initialt hög grundvattenyta. Detta till följd av att en stor mängd ytavrinning, som tidigare kunnat dräneras till den här delen av vattendraget, fastnade utanför vallarna istället för att avledas till vattendraget eller infiltrera den mättade marken. Dessa resultat kan sägas stödja teorin kring att invallningar har liten påverkan på grundvattenöversvämningar och visar på vikten av att undersöka och förstå styrande processer kring översvämningen av ett svämplan då åtgärder mot översvämning planeras.

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The objective of this study is to develop guidelines for the analysis of storm water retention ponds in Central Florida. Development of a combined seepage analysis considering both unsaturated and saturated groundwater flow incorporation into a systematic approach for storm water retention pond design will result in safer and more economical storm water management practices. The research was conducted in four phases: 1) A literature review. 2) A review of mathematical and empirical analysis of transient – unsaturated/saturated groundwater flow. 3) Construction and testing of a downscaled storm water pond model. 4) Incorporation of full scale percolation pond test data from ponds constructed and tested in Central Florida. The literature review was undertaken to research mathematical and empirical equations for both unsaturated and saturated groundwater seepage to be incorporated into the modelling and development of final system analysis. The review was concentrated on seepage studies conducted in subsoil conditions similar to those in Central Florida. It was found in the early review of literature that separate studies and modelling for unsaturated and saturated seepage are widespread and relatively well documented. However, documentation of combined groundwater seepage model, since the majority of storm water retention ponds in Central Florida experience both seepage condition (unsaturated/saturated) during the design storm event. Inspection of operational seepage ponds and interviews with regulatory agencies and consulting firms in Central Florida indicated that successful design of storm water retention ponds greatly depends on the accurate definition of the subsoil conditions and the seepage characteristics during a specific design storm event. Interviews with those responsible for pond design revealed that there is currently no widespread accepted design method, and most of the designs are based on mostly local experience. Also, history indicates that even though the unsteady seepage analysis is a complex phenomenon, there is usually very little money I the budget for its analysis and design. However, due to continuous increase of property values and the need to optimize pond sizing, the trend of under budgeting for seepage bond design is reversing. Application of the research results will yield a more accurate analysis which accounts for unsaturated and saturated seepage for sizing of storm water retention ponds in Central Florida. The analytical solutions developed from this research are a combination of acceptable mathematical and empirical groundwater seepage equations or dimensionless graphs modified for the purpose of storm water retention pond analysis.

Groundwater contamination with organic compounds, especially leaked or spilled fuels, is a serious and growing environmental problem which is difficult to remediate. Alcohol additives in gasoline present more urgent problems because of their relatively high mobility in the subsurface. This study focused on the subsurface biodegradation of two octane-boosting additives, methanol and tertiary butyl alcohol (TBA). A microcosm study was undertaken to determine the <u>in situ</u> biotransformation rates. While both alcohols were found to be amenable to biodegradation in the subsurface systems, the methanol removal rate was much greater than the TBA rate. By using sets of microcosms, several chemical additives were used in an effort to determine their effects on biodegradation. Organic substrates were added to microcosms containing low concentrations of TBA (about 1 mg/L) without evidence of stimulation or inhibition. Variation of pH (from pH 5.1 to 8.8) in microcosms containing methanol and TBA was part of the next experiment. This was combined with the addition of alternative electron acceptors, nitrate and sulfate. Variation of pH in non-amended and sulfate-dosed (100 mg/L) microcosms did not enhance the biodegradation of either alcohol. Nitrate addition inhibited both methanol and TBA biodegradation at lower pH levels, but enhanced methanol degradation when combined with base. TBA degradation was not affected by base addition except in the highest (initial pH 8.8) base dose. These microcosms exhibited TBA removal rates which were uniformly higher than all other treatments. / M.S.

Modeling of groundwater flow and chemical transport calls for a good characterization of heterogeneity of soil properties. The effects of variabilities of soil properties at local scale on the mean behavior of heterogeneous flows were investigated via Monte Carlo method. Assuming log-normal distribution of conductivity and capillary pressure head being a stochastic process, the mean behavior model defined by effective properties was derived to predict the mean behavior of heterogeneous flows. Effective parameters were evaluated numerically and were parameterized in terms of statistics of randomly distributed soil properties and flow characteristics. Monte Carlo simulations were performed to reveal the mean behaviors of steady unsaturated gravity flows, transient areal source infiltration and transient point source infiltration in heterogeneous porous media. The most important findings include (a) the effective conductivity is between the geometric mean and the arithmetic mean, (b) the effective conductivity is time dependent. The derivation of a mean behavior model and the capability of parametrizing the effective properties make it possible to use current deterministic models to predict the mean behavior with minimum changes in the constitutive relations, specifically adding the dependence on the flow characteristic to the K-S-P relations. The mean model derived in this study was applied to a field site, good agreement was found between the model prediction and field data. / Ph. D.

Groundwater is one of the least studied environments, yet many people rely on groundwater for their sole drinking water supply. Little is known about the indigenous microflora, but it is believed to be similar to oceanic planktobacteria due to the low nutrient concentrations occurring in both ecosystems. That is, groundwater microorganisms are atypically small, mostly Gram-negative cells. Also like the oceanic planktobacteria, they may have no affinity for surface attachment and may rely on dissolved low molecular weight organic substrates in dilute solution for their nutrition. Periods of metabolic dormancy may occur when natural substrate concentrations drop below the level required to sustain vegetative cell function. In these studies total cells present were determined by 4'6-diamidino-2-phenylindole (DAPI) epifluorescent counts. The percentage of those bacteria which were metabolically active was determined by a modification of the 2-(p-iodophenyl)-3-(p- nitrophenyl)- 5-phenyl tetrazolium chloride (INT) reduction method. Advantages of this method over others include more specific fluorochrome staining, ease of transfer of the cells to the slide, time saved, and ease of microscopic viewing. Heterotrophic uptake of aspartate, succinate, glucose and fructose by indigenous bacteria was measured and calculations of maximum uptake velocity (V_max) and a constant (K_t + S_n) equalling the natural substrate concentration (S_n) plus the half-saturation concentration (K_t) were made based on net assimilation (cellular retention) of radiolabeled substrate. Total counts by DAPI staining were 4-12.1 x 10⁴ cells/ml of which 17.4 to 20.85% were metabolically active (INT+). Mean maximum uptake velocities ranged from 1.73 to 2000 nmol/l/hr with aspartate being taken up at the highest rate followed by fructose, succinate and glucose. / Master of Science

Groundwater related courses are offered through several colleges at Virginia Tech. These classes enroll a diverse group of students with varied academic backgrounds and educational levels. Though these classes emphasize different aspects of groundwater resources, they lack a unified approach in instructional materials and learning methodologies for knowledge they do share. The goals of this research are to lessen the impact of variable student backgrounds and to better integrate the courses to improve teaching and learning, through the development of a multi-tiered, interdisciplinary website, Groundwater Interactive (GWI). GWI, as an educational technology, employs a variety of interactive multimedia. The primary educational components of the website include interactive and graphical models and quizzes, and a student-authored primer. An implementation strategy based on experiential and cooperative learning models is developed for application of the GWI tool in the classroom. An assessment methodology to evaluate the effectiveness of these new learning methods and techniques was also developed, but was not implemented as part of this work. / Master of Science