published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

The United States and Mexico share responsibility in preserving the quality of their international river system, the Rio Grande / Río Bravo, and several international treaties govern the quantity of water each country must give and take. Because no treaty establishes joint standards for the quality of the river, the North American Agreement on Environmental Cooperation (NAAEC) was created in 1993 as a declaration of principles and objectives concerning the conservation and the protection of the environment as well as a guide of concrete measures to further cooperate on these matters. One particular goal of the NAAEC was to improve water quality in the US-Mexico Border Region, ensuring a clean, safe, and reliable water supply for the area. Although the US and Mexican federal governments have made substantial technical and financial commitments through binational agencies like the North American Development Bank (NADB) and the Border Environment Cooperation Commission (BECC), few empirical studies have assessed the impact of binational expenditures on wastewater infrastructure in this region. This report uses longitudinal panel data regression models to estimate the impact of capital expenditures on water quality made by binational, federal, and state water quality management institutions from 1995 to 2012. This analysis considers expenditures made on both sides of the Rio Grande watershed that constitutes the international border, beginning with El Paso, Texas and ending in the Gulf of Mexico. / text

<p>The Eerste River is a river system which has, over the years, been subjected to human interference. The purpose of this study was to investigatge temporal and spatial trends in the water quality of the Eerste River between 1990 and 2005. The study results revealed that the major trends in the water quality of the Eerste River are more spatial than temporal.</p>

M.Sc. / This study aims to assess the potential impacts of intense feedlot activity on the aquatic freshwater environment, with reference to three feedlots, ranging in production size and all situated in the upper Vaal catchment area. Field assessments were done over a high flow and low flow period, while controlled exposures were also done to quantify a potential stress reaction to growth hormone exposure (using Clarias gariepinus as test organism). It was ascertained that water quality variables contributing towards differences between upstream and downstream environmental conditions are NH4 concentrations pH and conductivity. Lead concentrations were also periodically higher downstream from feedlot activity, in comparison with upstream. Taking the sediment assimilation potential of growth hormones into consideration, it was determined that Feedlot C showed the highest assimilation potential, while Feedlot A reflected the lowest. Alterations on family level invertebrate community structures indicated a categorical decline in abundances and species richness at sites situated downstream from feedlots. However, some clear seasonal influences were also observed. Further community and diversity analyses reflected alterations in invertebrate community structures that were not reflected in SASS 5 scores. With regards to the biomarkers applied in this study, it was noted that there was a significant (p<0.05) difference in the cellular energy allocation (CEA) between control and hormone exposed groups. The total amount of energy available (Ea) increased significantly for test organisms exposed to Diethylstilbestrol (DES), while there was a significant increase in energy consumption (Ec) of test organisms exposed to Trenbolone acetate (TBA). In addition to CEA, metabolic profiling of blood plasma was also performed, which indicated a definite ordination in metabolic constituents after fifteen days of exposure. This was established by subjecting the data to principle component analysis (PCA), which accounted for 83 % variance observed. The impacts and biotic responses identified in this study were contextualised with known literature on the effects of feedlot activity and growth hormone exposure on the aquatic environment. Finally, conclusions were drawn and recommendations made with regard to improving feedlot operational activities. The results obtained in this study contribute towards an integrated framework for the environmental management of feedlot activities.

D.Ing. / Measuring the efficiency of water utilities has been a constant challenge to various stakeholders in the water sector. There are several factors that influence the efficiency of utilities. The following study examines the different factors and establishes a model to quantify the efficiency of water utilities using limited number of variables. It utilises Fuzzy Logic to develop the measurement model. The developed method can also be used to configure a new water utility for efficiency. In addition, the research highlights some possible imperfections in the water policies that can result in an inherent inefficiency of a water utility. The developed model can assist in setting ceiling levels for utility's water assets and labour, to ensure efficiency. The model is generic and can be applied to any country or community, and can be used to configure water utilities for the poor. The Model utilised "Matlab Fuzzy Tool Box student version 2009a" software as a tool to develop the Fuzzy Inference Engine for Utility Efficiency. The study is a contribution to the domain of knowledge of water engineering science.

M.Sc. / Water resources in South Africa are scarce and need to be protected and managed in a sustainable way for future generations. Food supply is a great priority worldwide and the pressure to produce enough food has resulted in the expansion of irrigation and the steadily increasing use of fertilizers and pesticides to achieve higher yields. Rivers are impacted by agriculture through increased suspended sediment loads (which affects primary production, habitat reduction and introduction of absorbed pollutants), elevated nutrient inputs (which may increase the abundances of algae and aquatic plants), salinization and pesticide runoff (which eliminates species intolerant to these conditions and therefore impacts on the normal production of the river system). Aquatic biota plays an integral part in the functioning of aquatic ecosystems. Biological monitoring is used to assess ecosystem health and integrity. Biological communities reflect the overall integrity of the river ecosystem by integrating various stressors and therefore provide a broad measure of their synergistic effects. The research area falls within the Lower Vaal Water Management Area (WMA), which lies in the North-West and Northern Cape Provinces. The lower Vaal River and the Harts River (one of the tributaries of the Vaal) are the river systems under investigation in this study. Farming activities ranges from extensive livestock production and rain fed cultivation to intensive irrigation enterprises at Vaalharts (such as maize, cotton and groundnuts). The Vaalharts is the largest irrigation scheme in South Africa. Salinity is of concern in the lower reaches of the Harts- and Vaal Rivers, due to saline leachate from the Vaalharts irrigation scheme. Agricultural inputs are known to affect aquatic communities and chemicals (e.g. pesticides, herbicides, fertilizers) are extensively used in the Vaalharts irrigation scheme. At present there are no data on the effect of these chemicals on the aquatic biota of the lower Harts- and Vaal Rivers. The aims of this study were to assess the diatom- and macroinvertebrate community structures, ecosystem integrity and macroinvertebrate feeding traits (functional feeding groups – FFGs) in relation to land use.

A research report submitted to the Faculty of Engineering an the built environment, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, October 2016. / The study investigates the effectiveness of Rand Water’s Scientific Services’ skills development strategy for the assurance of quality drinking water as prescribed by the SANS 0241 National Drinking Water Quality Standard. The aim is to establish whether: 1) the present skills are adequate to provide the scientific data required for affirming drinking water quality and 2) the skills development taking place in the Scientific Services division is adequate for the level and quantity of scientific skills required for the future. There is also some discussion to understand the motivation for maintaining and increasing skills within the Scientific Services division for Rand Water. Assuring drinking water quality within Rand Water is the sole responsibility of the Scientific Services division. The division provides regular routine and non-routine drinking water quality monitoring, testing, data collection, analyses and reporting on the organisation’s performance against the SANS 0241 Drinking Water Quality Standards (SANS, 2006).The focus of the analysis is Scientific Services Division in Rand Water, although the discussion in view of the topic is not limited to the division. Production of drinking water encompasses two key aspects that must be investigated they are quality and quantity, however the close up analyses could only be successful completed for quality in the context of the quantity produced. Skills development planning within Scientific Services has always been based on the division’s feeder pipelines to be able to recruit from and retain scientific skills within the organisation. The division concentrates on Graduate, Bursar and Experiential Learner development ensuring a sustainable, trained and readily available pipeline of skills from which to recruit. Employees currently within the division both permanent and temporary form the type of scientific skills required for water quality monitoring and drinking water standard production and assurance. Employees have been placed within the functional scientific streams of the division and further by their levels of appointment and qualifications. The data analysis has also been done for the increasing of skills using the same framework. Age and gender was also included to show performance of the division in respect to transformation and equity. Equity in relation to growth is currently a global matter that is under scrutiny. The World Economic Forum has put equity in the spotlight to ensure countries look at their performance. The significance is that it has an impact on how the water resources in a country are distributed and managed. The Water Reforms in most developing countries have sparked large scale discussions around provisioning of water for all. Human Development and Water Resource Management are agendas that countries need to handle collectively with the ultimate outcome being achieving equity for all (UNDP, 2013). Rand Water’s Scientific Service skills data indicates that it has adequate scientific capacity to meet its present mandate of providing drinking water quality assurance for the organisation. There is some concern that the aging workforce is concentrated at management and specialists levels, therefore developing these skills for the next 5 to 10 years requires immediate attention. Transfer of skills and retention of skills requires careful strategic planning in order to attract a younger transformed workforce. The study shows that in as much as routine quality assurance is core, it is also equally critical to have employees who can troubleshoot within the context of the new environmental pressures and diverse operational conditions. The demand for quality drinking water over the last 110 years has increased throughout the country. The mandatory expansion of the organisation translates into sharing of human resources with other parts of the country to produce quality drinking water. Rand Water has been entrusted to take on the responsibility of other water utilities in the country and ensure that they reach the required standard for the production of quality drinking water. The full scope of the organisation’s mandate requires that it provide skills to handle the treatment of drinking water and wastewater in the near future. Although wastewater treatment is currently managed by the local municipalities, Rand Water will be having an active role to improve services. This would mean distributing the existing capacity within the organisation over a greater area of work along with a significant increase in the demand for scientific analyses of drinking water quality. The pace at which skills development takes place in Rand Water Scientific Services division shows that it will be able to meet the present needs. There are questions raised on the sustainability of the skills for the future. Maintaining and developing skills within the division is critical to be able to sustain the nature, structure and functioning of the division in its current form. The other factor that must also be maintained is the transformational equity demands of the country. The notion that there is a lack of experienced previously disadvantages scientists must be addressed directly to meet all the future demands of the sector, region and continent in a short space of time. / MT2017