Fault zones are potential paths for release of radioactive nuclides from radioactive-waste repositories in granitic rock. This research considers detailed maps of en echelon fault zones at two sites in southern Sweden, as a basis for analyses of how their internal geometry can influence groundwater flow and transport of radioactive nuclides. Fracture intensity within these zones is anisotropic and correlated over scales of several meters along strike, corresponding to the length and spacing of the en echelon steps. Flow modeling indicates these properties lead to correlation of zone transmissivity over similar scales. Intensity of fractures in the damage zone adjoining en echelon segments decreases exponentially with distance. These fractures are linked to en echelon segments as a hierarchical pattern of branches. Echelon steps also show a hierarchical internal structure. These traits suggest a fractal increase in the amount of pore volume that solute can access by diffusive mass transfer, with increasing distance from en echelon segments. Consequences may include tailing of solute breakthrough curves, similar to that observed in underground tracer experiments at one of the mapping sites. The implications of echelon-zone architecture are evaluated by numerical simulation of flow and solute transport in 2-D network models, including deterministic models based directly on mapping data, and a statistical model. The simulations account for advection, diffusion-controlled mixing across streamlines within fractures and at intersections, and diffusion into both stagnant branch fractures and macroscopically unfractured matrix. The simulations show that secondary fractures contribute to retardation of solute, although their net effect is sensitive to assumptions regarding heterogeneity of transmissivity and transport aperture. Detailed results provide insight into the function of secondary fractures as an immobile domain affecting mass transfer on time scales relevant to field characterization and repository safety assessment. In practical terms, secondary fractures in these en echelon zones are not indicated to limit release of radiation to the surface environment, to a degree that is significant for improving repository safety. Thus en echelon zones are to be regarded as detrimental geologic features, with potentially complex transport behavior which should be considered in the interpretation of in-situ experiments. / Graduation date: 2005

The decision to bury high level nuclear wastes in deep geological formations led to the study of the Hanford Nuclear Reservation as one of three possible sites for the first nuclear waste repository in the United States. To adequately evaluate the environmental impact of siting nuclear waste repositories in basalt aquicludes, it is essential to know the effects on parameter identification algorithms of thermal gradients that exist in these basaltic aquicludes. Temperatures of approximately 60° C and pressures of approximately 150 atms can be expected at potential repository sites located at depths of approximately 1000m. The phenomenon of over-recovery has been observed in some pumping tests conducted at the Hanford Nuclear Reservation. This over-recovery phenomenon may possibly be due to variations in the fluid density caused by thermal gradients. To asses the potential effects of these thermal gradients on indirect parameter identification algorithms, a systematic scaling of the governing field equations is required in order to obtain dimensionless equations based on the principle of similarity. The constitutive relationships for the specific weight of the fluid and for the porosity of the aquiclude are assumed to be exponentially dependent on the pressure gradient. The dynamic pressure is converted to the piezometric head and the flow equation for the piezometric head is then scaled in radial coordinates. Order-ofmagnitude estimates are made for all variables in unsteady flow for a typical well test in a basaltic aquiclude. Retaining all nonlinear terms, the parametric dependency of the flow equation on the classical dimensionless thermal and hydraulic parameters is demonstrated. These classical parameters include the Batchelor, Fourier, Froude , Grashof, and Reynolds Numbers associated with thermal flows. The flow equation is linearized from order-of-magnitude estimates based on these classical parameters for application in the parameter identification algorithm. Two numerical solutions are presented which predict hydraulic head given a continuous set of flow parameters. The first solution uses a totally numerical finite difference scheme while the second combines an analytical solution with a numerical solution. A radial coordinate system is utilized for describing an anisotropic confined aquifer. The classical inverse parameter identification problem is solved using an indirect method. This method is based on the minimization of a objective function or error criterion consisting of three parts: 1) least-squares error of head residuals; 2) prior information of flow parameters; and 3) regularization. An adjoint equation is incorporated into the method to eliminate the need to differentiate the heads with respect to the parameters being identified, increasing the stability of the algorithm. Verification of the parameter identification algorithm utilizes both "synthetic", computed generated input data and field data from a well test for a confined aquifer within the Columbia Plateau near Stanfield, Oregon. The method used is found to give parameter estimates which are both stable and unique. / Graduation date: 1992

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.

Most waste generated in South Africa is sent to landfills for disposal, and although it is confined in specific areas, it can potentially affect both above and below ground water resources, impacting environmental and public health. This is particularly relevant in a country where water supplies are limited and groundwater resources are prone to pollution. The primary objective of this study was to assess the performance of an upflow packed-bed bioreactor purposedesigned for the treatment of leachates produced by landfills in the Durban Metropolitan Area (DMA). The effect of parameters such as the nature of the biofilm support matrix, aeration rate and recycle rate on the efficacy of the system were investigated. Another major aim of the project was to develop a low maintenance technology that could, nonetheless, bioremediate leachate effectively at minimum cost. This aspect of process design is a crucial factor in areas where there is a shortage of both funds and skilled labour. The glass 132 l packed-bed upflow bioreactor was evaluated by measuring its efficiency in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD) reduction and ammonia removal. The bioreactor could be configured as a batch-type system, which was useful for comparing operating conditions; or as a continuous cascade system, which was used to assess its overall performance. Different biofilm support matrices viz. various grades of pine bark, plastic bioballs and ceramic noodles were evaluated in 22 l batch-type reactors. Leachates from five landfill sites were remediated during the course of the study, and only the leachate from Shongweni landfill, which had a remarkably low BOD:COD ratio (0.05), was intractable and could not be successfully treated; even in flask trials designed to test strategies such as augmentation of microflora and biostimulation. The other leachates investigated were from the Umlazi, Marianhill, Bisarsar Road (all general sites) and Bul-Bul Drive (a semi-hazardous site) landfills, all of which were remediated to some degree. Originally, leachate from the Umlazi landfill site was used, but it became unavailable when the site closed enforcing the use of other leachates for the remainder of the investigation. Leachates from Marianhill, Bisarsar Road and Bul-Bul Drive were treated simultaneously in duplicate operating the six-chambered bioreactor in the batchtype configuration. The highest COD removal efficiency (49 %) was obtained in the chambers treating the Bul-Bul Drive leachate, which was therefore used for further investigations. This leachate had the highest BOD:COD ratio and was therefore expected to be the most suited to biological remediation. The bioreactor performed best when plastic bioballs were used as biofilm support matrix with a relatively low level of aeration, although the uncomposted form of pine bark was used initially as the support matrix because it is inexpensive and readily available in South Africa. However, although satisfactory COD reduction (30 – 61 %) and ammonia removal (87 – 98 %) was achieved when the Umlazi leachate was treated, the possibility of compounds leaching out of the bark and affecting the quality of the treated leachate was a concern. Also, pine bark would be prone to mechanical degradation in a full scale operation. Of the other solid support matrices tested using the Bul-Bul leachate, COD removal efficiencies were superior with plastic bioballs (60 %) than with pine bark chips (29 %). The former therefore became the preferred biofilm support matrix. Aeration level did influence bioremediation of the Umlazi landfill leachate since those chambers aerated with an aquarium pump (0.05 – 0.1 litres air/litre leachate/min; 60 % COD removal) performed better than those aerated with a blower (0.6 -0.7 litres air/litre leachate/min; 42 % COD removal) and those that remained unaerated (44 % COD removal). Recycle rate did not significantly affect bioremediation, but the performance of the system was higher when operated in batch mode (up to 60 % influent COD removal), rather than in continuous flow-through (cascade) mode when only 37 % of the influent COD in the Bul-Bul leachate was removed. Under the latter conditions, most of the reduction occurred in the first four chambers and very little biodegradation occurred in the final two chambers. The cascade-mode will require some refinement to enhance the COD removal efficiencies achieved. However, it did eliminate 89 % of the BOD present in the raw leachate, producing a treated effluent with a consistent BOD:COD ratio of 0.05. The COD removal efficiencies achieved covered a wide range from a minimum of 23 % with Marianhill leachate to a maximum of 63 % with leachate from Bul-Bul Drive. These results are comparable with many of those reported by other authors treating landfill leachate. Up to 98 % of the ammonia was removed when the Umlazi leachate was treated. However, ammonia removal from the other leachates tested was erratic. Although the treated leachate from this system could not be released into the environment without further remediation, the reduction in concentration of pollutants would allow its return to the local water supply via a wastewater treatment plant. This was achieved without temperature and pH regulation or addition of extraneous nutrient sources. A cost-effective, low maintenance technology such as this one would be a useful tool for the treatment of effluents such as landfill leachate in countries like South Africa where although water conservation is urgently required, resources for highly sophisticated effluent remediation are often not readily available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Since 1994, South African governance has been in transition from bureaucracy to democracy. In tenns of democracy, local government is specifically tasked with providing goods and services equitably and sustainably not only to it's citizens, but along with them. In South Africa, the provision of refuse removal services and landfill sites for waste disposal are under local government control. Recently, Durban Solid Waste, a municipal waste management contractor in the Durban Metropolitan Area, KwaZulu-Natal, South Africa embarked on a comprehensive exercise, the first of it's kind in the country. to locate, plan, develop and operate new generation landfill sites with the aid of a public participation process involving capacity building which is a requirement of legislation. It is in the North Zone of this area that the existing landfill is to close by December 2000, and so there is an urgent need to locate and develop a new landfill site for the region. It is the capacity building and public participation process of the North Zone landfill site selection process which is the subject of this study. A case study format provides an intensive examination of the public participation and capacity building process. Qualitative research methodology was employed to compliment the interp retive approach undertaken in the research process, which used conceptual frameworks drawn from literature for the data interpretation. Data were collected via participant observation at meetings and workshops, and semi-strucrured interviews with stakeholders of the North Zone process. The research findings revealed that while a variety of capacity building and public participation means suggested by government policy have been utilised., none of the statutory principles of public participation for landfill siting have been implemented satisfactorily by participants in the North Zone public participation process. The findings also indicate that the predominant type of public participation being followed in the North Zone is instrumental in nature. and thus in the main does not exhibit outcome measures of empowerment which are associated with transformative participation. Furthermore. the findings demonstrate that while capacity building made the North Zone public participation process more democratic than previous landfill site selection exercises, principles of equity were only satisfied to the extent that the statutory requirements, the will of the developer, a shortage of time and adequate funding pennitted. The recommendations suggest: lobbying for changes to the statutory requirements. ways of building trust between stakeholders. activities to promote equity and democracy, and the use of more suitable means of capacity building and public participation for landfill site selection public participation processes in South Africa / Thesis (M.Sc.)-University of Natal, Durban, 2000.

Municipal Solid Waste generation has become an inevitable consequence of lifestyles and daily living. However, the nature (quantity and quality) of this waste stream can vary and is largely dependent upon the manner in which waste production is managed, by both government and the public. The increasing practices of littering, dumping and burning of solid waste by households (and industries though not extensively dealt with in this study) in South Africa has led to the finding that municipal solid waste is being irresponsibly managed. In this regard, it becomes necessary to investigate the attitudes and behaviour of individuals and households toward solid waste practices, which further include mitigating measures such as reduction, reuse and recycling for the generation of solid waste. The role of the South African government in providing a refuse removal and safe disposal service to all citizens is suggestive of the responsible role of government to ensure that solid waste is being effectively managed by all sectors of society. The aims of this study in light of the above were to review the municipal solid waste policies and strategies of local government authorities in South Africa, highlighting the shortcomings and discrepancies that exist between legislative policies and actual management practices; which is also reflective of the attitudes and approaches to solid waste management by households. This was achieved by focusing on the case study of the Msunduzi Municipality and included investigations into socio-economic and cultural influences on solid waste disposal practices. The objectives of the study were achieved by means of a questionnaire survey that elicited specific responses from 650 sampled households in five suburbs of differing socio-economic status. A further analysis to identify the nature of household municipal solid waste for landfilling from three suburbs of differing socio-economic status was conducted by categorizing 25 tons of garbage at the New England Road Landfill Site, leading to inferences about consumer purchasing power and disposal practices. Further, key personnel in the Msunduzi Municipality’s waste management division were interviewed to ascertain the solid waste challenges faced at local municipal and national levels of government. The study revealed several significant findings of which the most important is that the implementation of South Africa’s national municipal solid waste legislation policies and strategies are inconsistent with local government practices and procedures; thus compromising equity, efficiency, effectiveness and the sustainability of municipal solid waste disposal. Factors contributing to this are shown to be inadequate management and service delivery. The research has shown that monitoring and control systems which purported to ensure environmental sustainability are lacking and inadequately address issues where the implementation of municipal solid waste regulations are in contravention with national solid waste policies. The outcomes of the questionnaire survey and the assessment of household municipal solid waste for landfilling reveal that socio-economic status and culture do in fact influence the nature of solid waste and the disposal methods used by residents. The receptiveness of households towards adopting suggested municipal solid waste disposal practices was also investigated. The non-compliance of residents with municipal solid waste legislation and policies points towards a lack of monitoring and control measures, thereby not providing for a sustained and adequate service delivery which is environmentally sound. The research further suggests that all sectors of the South African public and the government are inadequately informed in terms of aspects of municipal solid waste. This has led the researcher to recommend that further education and awareness campaigns and its role in environmental sustainability are needed so that a sharing of responsibility between government and the public can be effected to aid municipal solid waste management in the country. It is argued that the insight into the roles of socio-economic status and cultural influences over solid waste practices provide a platform from which municipal authorities can work to specifically address the problems associated with municipal solid waste at a community level. It is the task of the national government to ensure that South Africa’s municipal solid waste is being responsibly managed at the local municipal levels so that the health and safety of the environment and its citizens are suitably addressed, hence the focusing on solid waste legislation and national policies (which have been recognized internationally as being environmentally sound and sustainable) must be translated in terms that local municipalities can adopt, assuming that they have been sufficiently empowered in terms of both knowledge and adequate budgeting. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

The temporal fate of selected parameters, including redox potential; pH; phenol; nitrates; sulphates; copper and zinc, of a young synthetic acetogenic phase landfill leachate was assessed by perfusing a series of sequential soil (Hutton) microcosms (arrays) at two hydraulic loading rates (HLR). We chose HLRs that were representative of areas in South Africa with typically elevated rainfall (Pietermaritzburg – HLRh) and one with relatively low rainfall (Kimberley – HLRl). Preliminary phenol, copper, and zinc adsorption investigations on gamma radiation sterilized soil and unsterilized soil revealed superior adsorption rates for each compound in the unsterilized soil. This revealed the importance of the biological component of soil in phenol, copper, and zinc attenuation in soil. The results presented in this thesis suggest that the HLR of leachate into soil arrays contributes to significant differences in the fate of the landfill leachate parameters mentioned earlier. In addition, we assessed the temporal and spatial succession of bacterial community diversity in each of the soil arrays by polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Prior to this, we compared two soil DNA isolation techniques, the modified method of Duarte et al. (1998) (Bead Beat) and the commercial Mo-Bio UltraClean™ Soil DNA isolation kit (Kit). The DNA isolated by the Kit method was significantly superior regarding purity and absence of DNA fragmentation. However, the Bead Beat method produced a significantly higher yield per reaction before further purification with Wizard™ Clean-Up columns produced DNA extracts of similar purity at the cost of a significant reduction in DNA yield. The Kit method was chosen for future DNA isolation and PCR-DGGE based on the quality of the PCR amplicons generated from the Kit isolated DNA. PCR-DGGE was further optimized by comparing the efficiency and sensitivity of a silver stain against ethidium bromide. Silver stain generated DGGE gels with greater number of bands (species richness – S) and stronger band signal intensities. Captured DGGE fingerprints generated data that were subjected to the Shannon-Weaver Index (H’) and the associated Shannon-Weaver Evenness Index (EH) to measure the change in spatial and temporal bacterial diversity. There was a significant shift in S and H’ for both HLRs but a significant change in EH was only observed for HLRh. Furthermore, a temporal comparison of S and H’ between both HLRs revealed significant differences throughout the investigation. Canonical Correspondence Analysis (CCA) revealed spatial distribution of bacterial community diversity with depth. Effects of phenol concentration, redox potential, and pH of the effluent leachate on bacterial community diversity was tentatively assessed by three-dimensional graphical representation on PlotIT 3.2 software. Bacterial community diversity showed a decrease with elevated pH and phenol concentration along with decreasing redox potentials for both HLRs. While this study reveals the spatial and temporal dynamics of bacterial community diversity in situ, it provides important evidence with respect to: (i) the effects of rainfall / leaching rates (HLR) on spatial and temporal bacterial community succession; (ii) the importance of the biological component in natural attenuation; (iii) the ability of soil, previously unexposed to landfill leachate, to initiate natural attenuation of phenol and other leachate constituents; (iv) the capacity of PCRDGGE to fingerprint successional changes in bacterial community diversity, (v) and the potential to clone and sequence selected members of bacterial associations for future reference in environmental remediation strategies. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Submitted in fulfillment of the requirements of the degree of Master of Health Sciences in Environmental Health, Durban University of Technology, Durban, South Africa, 2016. / In South Africa, under-five childhood morbidity and mortality rates have increased due to diarrhoea with acute diarrhoea posing a major public health threat especially, in informal settlements. Therefore this study sought to, a) investigate community knowledge, attitudes, behaviour and practices (KABP) regarding domestic waste and childhood diarrhoeal management, b) to enumerate and identify diarrhoeagenic E.coli species from soil samples extracted from open waste dump sites and c) to investigate any association(s) with diarrhoeagenic E.coli and potential risk of contracting diarrhoea. This two-phased cross-sectional study in six informal settlements in the greater Durban area constituted, respectively, of the administering of questionnaires to 360 primary caregivers and; sampling the prevalence of diarrhoeagenic E.coli (DEC) in waste dumps using quantitative polymerase chain reaction methodologies. Relationships between socio-demographic and educational status to determine potential household risk factors towards under-five diarrhoea prevalence were assessed. The KABP results identified domestic waste and greywater disposal, mother and child method of sanitation, personal and domestic hygiene practices and mechanical vectors as significant contributory risk factors. Of concern is that more than 80% of under-five children played in or near faecally-contaminated waste dump sites. The recovery of four DEC pathotypes including enterohaemorrhagic E.coli, enteropathogenic E.coli, enterotoxigenic E.coli and enteroaggregative E.coli suggest that its persistence in waste-dump soil has the ability to cause under-five diarrhoea in both sporadic and endemic settings. This commonly transmitted hand-to-mouth illness will necessitate and place huge demands on the primary catalysts of change i.e. local governmental role players and caregivers. These change agents have to ensure highly consistent levels of domestic and personal hygiene and implement feasible reduction strategies to waste-dump exposure of diarrhoeal-causing pathogens, particularly among under-five children living in Durban’s informal settlements. / M

This study investigated the establishment of vegetation cover planted in plug and seedling form in the closure phases of the Umlazi Landfill. It also investigated the various facets of the closure process of the Umlazi Landfill and the effect these have on the establishment and choice of vegetative cover, and the grass technology used to make the establishment of vegetation a success. The setting up of trials and the gathering of basic data were undertaken to assess the alternative vegetation options available to researchers. The cover provided by the grasses was assessed in the investigation. The capping of landfill sites is a relatively new approach and it is soon to become a mandatory requirement by the Department of Water Affairs and Forestry (Minimum Requirements for Waste Disposal) (DWAF, 1998). This systematic investigation used in the closure of the Umlazi Landfill, will provide a model for the capping of landfills in South Africa. Seeing that this was the first hazardous (H:h) landfill site in the country to be closed according to the Minimum Requirements for Waste Disposal (DWAF, 1998), every attempt was made to ensure that all aspects in the closure of the site met with the Minimum Requirements. The Minimum Requirements document mentions only briefly that the landfill must be vegetated with some grass type. Prior to 1994, capped landfill sites were usually planted with traditional grass seed mixes and these were not widely successful, as seen on many older landfills that have been partially or completely capped, and where vegetation cover is sparse. There is much literature in the developed countries on the closure of landfills (e.g., Erickson, During the site inspections in June 2001 and February 2002, it was noted that many species of alien plants had established themselves in the poor soil conditions. This made it even more important to find indigenous vegetation to vigorously establish itself that would prevent the establishment of alien invaders. Samples of grass species established on some part of the site were also taken for identification. The dominant grass was identified as Cynodon dactylon. In view of establishing a balanced vegetative cover on top of the Umlazi Landfill, Acacia karoo trees (in seedling form) were also planted. Three bunch grass species, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, were tested to see if thatching grass could be grown on the site to generate a cash crop for local residents of Umlazi township. Preparation and planting of the capped areas took place in the latter part of 2003 and were completed in early 2004. Measurements and field data were recorded and statistically analysed. The trials revealed three key findings: Firstly, both creeping grasses studied, namely Cynodon dactylon var. “Sea Green” and Panicum natalense var. ”Natal Buffalo Grass” grew well on the site. Initially P. natalense grew faster but after a month, C. dactylon overtook it. At the end of the trial (six months, P. natalense provided a higher level of soil cover. However, C. dactylon grew more consistently over this period. Hence both species provided good growth and cover on this site. Secondly the three bunch grasses, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, all grew well and had similar survival rates. Hence the potential for growing these grasses as a cash crop has potential. Thirdly, all the Acacia karoo trees survived, i.e., they achieved 100% survival. The average height increase and stem width was similar in all trials and growth was consistent over the six month growing period. Hence the tree species would be a good choice for planting on landfills in its ecologically suitable zones. It is therefore feasible to envisage the planting of a mixture of grasses under the cover of A. karoo trees, to provide a balanced mixture of indigenous grasses to cover a freshly capped landfill. Such a system should provide for stable growth of vegetation for many years. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008

Altered flows that are low-MgO chemical types of the Grande Ronde Basalt crop out in the steep walls of the Grande Ronde River canyon near Troy, Wallowa County, Oregon. The alteration effects in these flows are being investigated as a natural analog system to a high level nuclear waste repository in basalt. The flows within the study are referred to as the analog flow, in which the alteration effects are the strongest, and the superjacent flow. The analog flow crops out at Grande Ronde River level and a roadcut-outcrop is developed in the flow-top breccia of this flow. The two flows have been divided into flow zones based on intraflow structures observed in the field and primary igneous textures observed in thin section. These zones include, from the base upward, the flow interior, transition, and flow-top breccia zones of the analog flow, the interflow contact zone, and the flow interior and flow-top breccia zone of the superjacent flow. The intraflow structures and textures of the transition and interflow contact zones are atypical of Grande Ronde Basalt flows. The transition zone is transitional in textures between the flow interior zone and flow-top breccia zone, and includes holocrystalline spines mantled with fused in situ breccias. The interflow contact zone reflects the dynamic interaction during the emplacement of the superjacent flow manifested as invasive basalt tongues, clasts shed from tongues, pipe vesicles and tree molds, and pockets of breccia caught up in the base of the superjacent flow.