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Stormwater provides a direct link between urban infrastructure and the urbanised natural environment. In particular, highway drainage presents a high risk of pollution when compared to other urban land use areas (Ellis et al., 2012); introducing heavy metals, suspended solids and hydrocarbons to urban waterways. This research investigated runoff from the R300 highway, located in the greater Cape Town area. The City of Cape Town Management of Urban Stormwater Impacts Policy requires the treatment and attenuation of stormwater from developments within the city, and proposes Sustainable Drainage Systems (SuDS) as a means to achieve this (CSRM, 2009b). SuDS are structural and process controls that attenuate surface drainage, improve runoff water quality, provide amenity and deliver ecosystem services. This study characterized the R300 runoff through a sampling program and modelling exercise in order to provide an indication of the ability of SuDS to manage highway runoff in South Africa. Sediment and runoff samples were collected from the road surface and an undeveloped parcel of land adjacent to the highway. The sampling results showed that heavy metals, suspended solids and phosphorus are present in significantly greater concentrations in road runoff compared to rainwater from the same area. The concentration of aluminium, copper, lead, zinc and phosphorus exceed the Department of Water and Sanitation's water quality guidelines for aquatic ecosystems in excess of 1000%. The concentration of heavy metals, phosphorus and fats, oils and greases was significantly greater in road sediment compared to sediment from the surrounding area. Barring copper, all contaminant concentrations in the road surface sediment are less than the maximum concentration required to protect ecosystem health. The R300 rainfall-runoff response was modelled in PCSWMM to evaluate the performance of SuDS such as infiltration trenches, bioretention areas and swales for managing highway runoff in terms of quantity and quality. The modelling exercise showed SuDS to be a viable means to attain the City of Cape Town's stormwater objectives, provided that SuDS are implemented in treatment trains along the entire road length.

The critical situation in the water sector continues to jeopardize developmental principles and undermine strategies for poverty eradication. On the assumption that the failure in service provision can be largely attributed to an inability to holistically address all aspects of urban water management, a systems approach was used to develop a relevant and robust sustainability index which assesses the capacity of a city or a portion thereof to be sustainable. This thesis details the process of developing the Sustainability Index (SI) for a multidimensional assessment of urban water systems. In this research, an analysis of the current problems facing developing cities, particularly in Sub-Saharan countries, was undertaken. This was done so as to provide some insight into the current developmental issues hindering sustainable development. An examination of the urban water cycle was also carried out to illustrate the links within the cycle and between the various water uses and services. A process model was developed which addresses the multi-dimensionality of sustainability and the dynamism of urban water systems. This model combines aspects of the iterative procedure for assessing environmental sustainability introduced by Lundin et al. (2002) with the step-wise process proposed by Nardo et al. (2005).

The Bill of Rights in the Constitution of South Africa mandates the promotion of human dignity, equality, and freedom. To attain these three mentioned aspects, the Bill of Rights stipulates that every person has the right to safe water and sanitation and this is done to improve the welfare of every citizen. South Africa has approximately 13% (7.27 million) of its population staying in informal settlements. Most of these informal settlements were formulated during the land invasion and so on and has since been increasing throughout South Africa. This study sought to assess whether informal dwellers have access to safe water and sanitation, what is the state of the water and sanitation facilities. The assessment was conducted in terms of the Bill of Rights in the Constitution of South Africa and WHO. Marikana informal settlement in Cape Town was used as a case study. Safe water and sanitation to all remain a challenge in South Africa, notwithstanding the commendable efforts since 1994, to provide access to safe water and sanitation as a right to all people. Based on empirical findings and analysis of relevant documents, the study views the water and sanitation in SA informal settlements as unsafe. The sanitation facilities are inadequate thus contributing to existing open defecation. The coverage of the water and sanitation facilities is not enough, therefore, compromising the right to access safe water and sanitation. The findings show evidence of non-operational water supply infrastructure. The uncleanliness of the existing sanitation facilities contributes to health issues like water-borne diseases. The sanitation facilities lack the human right factor, for an example, facilities are not designed to accommodate the elderly and physical disable people. Though South Africa made commendable progress in providing access to water and sanitation nationally, the inequality in the provision of safe water and sanitation exists; there is lack of freedom due to the poor safety of public facilities and overcrowded settlements, and the protection of human dignity is still an issue in informal settlements. In general, while the study identifies the existence of comprehensive national legislative and policy frameworks in support of providing safe water and sanitation in informal settlements, there are various challenges such as availability of land, inadequate housing, policy implementation, infrastructure maintenance and so on, that hinder the right to safe water and sanitation and has a possibility to hinder the fulfillment of South Africa's vision 2030 goal to provide access to piped water and flush toilets by all people.

This thesis develops and applies a number of methods for systems analysis and assessment within the field of sustainable urban water. These focus on the evaluation of distributed strategies. In line with arguments made within the thesis, the methods developed assess urban water on a whole-system basis, with the system defined in terms of the services provided. Further, the thesis argues for sustainable urban water planning to take a pluralist stance; both in the conception of sustainable urban water and the strategies considered. The challenges of sustainability and sustainable development are fundamentally problems of complex systems. Planning and assessment of sustainable urban water therefore require a systems-approach. Systems-thinking is not, however, a unified body of knowledge and this thesis develops a unique perspective on systems-thinking which is used to critically review the fields of sustainable urban water and its assessment. Within these reviews, the thesis develops a framework for understanding sustainable urban water in terms of a number of varied approaches, and describes a feasible theoretical basis for assessing sustainable urban water. Many, so called, sustainable strategies are small-scale and distributed in nature. Distributed strategies include decentralised systems, embedded technologies, and local measures for conservation. Traditional systems analysis methods have failed to account for distributed strategies. To adequately include distributed strategies, this thesis argues that assessment methods will need to be based on whole-system modelling, utilise end-use models of service provision, and include - in the form of a demand forecast - a time dimension in relation to service provision. This thesis proposes new methods for microbial risk assessment on a whole-system basis and Least cost planning for (urban water) Sustainable Scenarios (LeSS). A novel evaluation framework for least cost planning for water supply, which provides an equivalent comparison of demand- and supply-side options, is also developed. These methods are illustrated through case studies. These case studies illustrate the potential of distributed strategies. When assessed on an equivalent basis, in various examples, distributed strategies are shown to be particularly cost effective. Decentralised wastewater reuse systems are also shown to impose a theoretically lower level of pathogen risk on the community than equivalent centralised reuse schemes. Despite the advances in assessment methodologies made within the thesis, further development of practical tools for assessing and planning sustainable urban water remains an urgent goal.

This thesis develops and applies a number of methods for systems analysis and assessment within the field of sustainable urban water. These focus on the evaluation of distributed strategies. In line with arguments made within the thesis, the methods developed assess urban water on a whole-system basis, with the system defined in terms of the services provided. Further, the thesis argues for sustainable urban water planning to take a pluralist stance; both in the conception of sustainable urban water and the strategies considered. The challenges of sustainability and sustainable development are fundamentally problems of complex systems. Planning and assessment of sustainable urban water therefore require a systems-approach. Systems-thinking is not, however, a unified body of knowledge and this thesis develops a unique perspective on systems-thinking which is used to critically review the fields of sustainable urban water and its assessment. Within these reviews, the thesis develops a framework for understanding sustainable urban water in terms of a number of varied approaches, and describes a feasible theoretical basis for assessing sustainable urban water. Many, so called, sustainable strategies are small-scale and distributed in nature. Distributed strategies include decentralised systems, embedded technologies, and local measures for conservation. Traditional systems analysis methods have failed to account for distributed strategies. To adequately include distributed strategies, this thesis argues that assessment methods will need to be based on whole-system modelling, utilise end-use models of service provision, and include - in the form of a demand forecast - a time dimension in relation to service provision. This thesis proposes new methods for microbial risk assessment on a whole-system basis and Least cost planning for (urban water) Sustainable Scenarios (LeSS). A novel evaluation framework for least cost planning for water supply, which provides an equivalent comparison of demand- and supply-side options, is also developed. These methods are illustrated through case studies. These case studies illustrate the potential of distributed strategies. When assessed on an equivalent basis, in various examples, distributed strategies are shown to be particularly cost effective. Decentralised wastewater reuse systems are also shown to impose a theoretically lower level of pathogen risk on the community than equivalent centralised reuse schemes. Despite the advances in assessment methodologies made within the thesis, further development of practical tools for assessing and planning sustainable urban water remains an urgent goal.

This study explored the relationship between increased proportions of imperviousness in a watershed on surface water quality and examined the effectiveness of using remote sensing to systematically and accurately determine impervious surfaces. A supervised maximum likelihood algorithm was used to classify the 2008 high resolution National Agriculture Imagery Program (NAIP) imagery into six classifications. A stratified random sampling scheme was conducted to complete an accuracy assessment of the classification. The overall accuracy was 85%, and the kappa coefficient was 0.80. Additionally, field sampling and chemical analysis techniques were used to examine the relationship between impervious surfaces and water quality in a rainfall simulation parking lot study. Results indicated that day since last rain event had the most significant effect on surface water quality. Furthermore, concrete produced higher dissolved organic carbon (DOC), dissolved organic nitrogen (DON), potassium and calcium in runoff concentrations than did asphalt. Finally, a pollutant loading application model was used to estimate pollutant loadings for three watersheds using two scenarios. Results indicated that national data may overestimate annual pollutant loads by approximately 700%. This study employed original techniques and methodology to combine the extraction of impervious surfaces, utilization of local rainfall runoff data and hydrological modeling to increase planners' and scientists' awareness of using local data and remote sensing data to employ predictive hydrological modeling.

Water is one of Earth's most valuable resources and one of Earth's most threatened resources. Continuously increasing population growth coupled with changing climate has resulted in the depletion of water sources. As a result, investigations into alternative water sources are being conducted worldwide. One such alternative water source is groundwater abstraction. Groundwater abstraction involves the abstraction of water from an underground source. The volume of water that can be sustainably abstracted is governed by legislation. Groundwater typically requires treatment before it can be distributed to the general population for use, and thus the implementation of large-scale groundwater abstraction projects involves large capital outlays, as well as monthly operational outlays. The feasibility into the implementation of large-scale groundwater abstraction projects is therefore of interest to stakeholders involved in the water supply industry. The lifecycle of a recently implemented large-scale groundwater abstraction project was analysed in order to determine its feasibility. The project was implemented by Drakenstein Municipality in the Western Cape in 2017. The project involved identifying groundwater abstraction points that could provide sustainable volumes of water. The water quality of each groundwater abstraction point was then investigated for any outlying parameters according to SANS 241-1:2015 guidelines for potable water. Groundwater abstraction water treatment plants were then designed in order to treat the combined sustainable flow rates of water at their specific water qualities. The treated water from each groundwater abstraction water treatment plant was then analysed in order to confirm compliance with the SANS 241- 1:2015 guidelines, before the booster pumps were commissioned and commenced with their continuous supply of potable water into the network. The capital expenditure associated with each of the groundwater abstraction water treatment plants was obtained from the Engineer, Aurecon. In addition, the estimated monthly operational expenditure was computed. These expenditures were used to determine the feasibility of the large-scale groundwater abstraction project by computing the payback period and comparing this period to the design life of each of the groundwater abstraction water treatment plants. In addition, the monthly savings applicable to the municipality as a result of the project's implementation was computed. Finally, the feasibility into varying flow rates of groundwater abstraction water treatment plants, and varying water quality of groundwater abstraction points was investigated. Two sites were identified within the municipal area, each with four groundwater abstraction points capable of delivering a combined 5.18 ML/day and 1.62 ML/day. These sites were identified as Boy Louw Sportsgrounds and Parys Sportsgrounds respectively. Although the sites were only 2.60 kilometres apart, the water quality of the combined flow rates indicated that the groundwater abstraction points were accessing two different water sources. The combined sustainable flow rate at Boy Louw Sportsgrounds required turbidity, iron and manganese removal, as well as disinfection. The combined sustainable flow rate at Parys Sportsgrounds required turbidity removal and disinfection. Groundwater abstraction water treatment plants were then designed to treat the water at Boy Louw Sportsgrounds and Parys Sportsgrounds. Boy Louw Sportsgrounds involved the distribution of equipment across seven shipping containers, whilst Parys Sportsgrounds involved the distribution of equipment across three shipping containers. It was found that the groundwater abstraction project was feasible with a payback period of three years. This payback period fell well within the 10-year design life of each groundwater abstraction water treatment plant. In addition, it was found that the municipality would be subject to a 72% monthly saving in water costs as a result of utilising the groundwater abstraction water treatment plants, as opposed to purchasing water in bulk from the City of Cape Town. It was found that the payback periods of Boy Louw Sportsgrounds and Parys Sportsgrounds were two and five years respectively. Although Boy Louw Sportsgrounds delivered almost three times the potable water flow rate than that of Parys Sportsgrounds, its payback period was three years sooner. In addition, it was found that the municipal savings as a result of Boy Louw Sportsgrounds was 8% more than that of Parys Sportsgrounds. It was therefore concluded that the larger the flow rate of water to be treated, the more financially feasible the project. In addition, it was determined that the more water quality parameters lying above the upper limits of SANS 241-1:2015 guidelines for potable water, the more treatment processes would need to be implemented resulting in additional capital and operational expenditure. It was therefore concluded that the more water quality parameters requiring treatment, the less financially feasible the project. Finally, it was determined that the feasibility of the large-scale groundwater abstraction project is limited by the rate at which the municipality purchases water in bulk from the City of Cape Town. As long as the bulk water purchase tariff remains above R 2.85/m³, the project will remain feasible. Should the bulk water purchase tariff fall below this value, the project no longer remains feasible as the payback period of the project exceeds the design life of the groundwater abstraction water treatment plants.

Dual Digestion is a two-stage system that combines autothermal thermophilic aerobic pre-treatment with conventional anaerobic digestion. The practicability of the system using pure oxygen is well proven. Disadvantages are the high cost of the pure oxygen and the absence of a detailed evaluation of anaerobic digester performance. This report discusses the results of a full-scale investigation into the dual digestion system (184m³ aerobic reactor and 1800m³ anaerobic digester), carried out in two phases: In the first using air alone for oxygenating the aerobic reactor and in the second using a combination of air and pure oxygen. During both phases the performance of the anaerobic digester was also monitored, but in greater detail in the second phase as far as the final sludge product is concerned. In phase I, with air, it was possible to maintain thermophilic temperatures in the aerobic reactor throughout the year. However, the required retention times were relatively long (3-6 days) in comparison with the pure oxygen reactor (~1 day) due to the high vapour heat losses. At long retention times, the volatile solids (VS) destruction was appreciable (~25%) and the reactor tended towards an autothermal thermophilic digester. Foaming, although unpredictable in its occurrence, significantly improved aerobic reactor performance by doubling the oxygen transfer efficiency. From liquid and gas mass and heat balances it was found that the specific biological heat yield and respiration quotient were approximately constant at 12.8 MJ/kg(O₂) and 0. 70 mol(CO₂)/mol(O₂) respectively over a wide range of operating conditions and consistent relationships between VS removal, heat generation, and oxygen utilisation could be established. Based on information collected, it was concluded that increased treatment capacity and greater temperature control of the aerobic reactor could be provided by supplementing air oxygenation with pure oxygen. In phase II, using a combination of air and pure oxygen, much higher loading rates on the aerobic reactor were possible. Thermophilic temperatures could be maintained at short retention times (1-2 days). Unfortunately, no foaming occurred during this period. Consequently, the benefit of improved oxygen transfer efficiency of the air oxygenation system, produced by the foam, could not be exploited. Liquid and gas mass and heat balances confirmed the specific heat yield and respiration quotient values and the relationship between oxygen utilisation, VS destruction and biological heating. During phase II, the anaerobic digester operated at a retention time of ~10 days. The sensible heat content of the hot sludge from the aerobic reactor was sufficient to force the digester into the thermophilic temperature range. The stability of the anaerobic process and final sludge product at this short retention time was monitored with % VS removal and residual specific oxygen utilisation rate tests and found to be similar to that of conventional mesophilic anaerobic digestion at 20 days retention time. Dewaterability as reflected by the specific resistance to filtration (SRF) was found to be poor, but 11ot much worse than for conventional mesophilic digestion. Sufficient information was obtained during phases I and II to allow a mathematical model to be compiled, which could reasonably reliably simulate all the main operating parameters of the dual digestion system. The model provided a means for assessing different system configurations with mesophilic or thermophilic digestion, with and without heat exchange or gas engine external heat sources, allowing technical and economical (capital and operating) feasibility to be evaluated and compared with that for conventional digestion. From both the experimental and modelled results, all the claimed benefits of the dual digestion system were verified with the exception of the claim that aerobic reactor heat pre-treatment of the sludge allows the anaerobic digester to operate at short retention times (~10 days). However, the digester can be operated at 10 days retention provided its temperature is in the thermophilic range, in which case a sufficiently stable sludge is produced; at mesophilic temperatures, a retention time of 15 days or longer is required to produce a sludge of equivalent stability to that from conventional mesophilic digestion. Consequently, it is not the stability of the anaerobic process per se that governs the minimum retention time but the quality required for the final sludge product. The aerobic reactor is an appropriate pre-treatment stage for the thermophilic digester because it provides the necessary temperature and pH buffering to allow stable operation in the thermophilic range. It is concluded that where application of conventional anaerobic digestion is contemplated, whether for new installations or for upgrading existing plants, the dual digestion system should be seriously considered as a possible option. It competes favourably both technically and economically with conventional mesophilic digestion and produces a superior sludge product which can be beneficially utilised in agriculture.

Advanced water metering is part of a much larger movement towards smart networks and intelligent infrastructure. However, where advanced metering technology is focused more towards the need to obtain meter readings without human intervention in other parts of the world, in South Africa and other developing countries, advanced water metering (in the form of prepaid meters or water management devices) has been developing along a parallel path, driven by the need to provide services to previously unserved communities and deal with the problems caused by rapid urbanisation. In this report, conventional water metering is defined as systems using water meters that display their readings on the meters themselves and advanced water metering as systems that add additional components or functionality to a metering system. Advanced metering has the potential to provide substantial benefits if appropriately applied. However, compared with conventional metering, these systems are considerably more expensive and complicated, and often rely on technology that is still being developed. Advanced metering systems therefore carry a higher risk of failure, poor service delivery and financial losses unless the system is implemented with careful design and thorough planning. This report describes a number of case studies of the application of advanced metering in South Africa. The case studies were evaluated according to the evaluation framework described in Appendix A and their detailed evaluations are included in each relevant chapter. Evaluations were done in four areas: technical, environmental, social and economic. The technical evaluation is based on the systems complying with the relevant national metering standards and good metering practice, the environmental evaluations on battery disposal and water savings and the social evaluation on broad socio-economic indicators. It should be recognised that social issues are particularly complex and that no general evaluation framework can accurately predict whether an advanced metering system will be accepted by a particular community. The economic evaluations were based on reductions of the current system cost and not absolute values. Economic performance indicators included the effective surplus (income minus expenses over averaged over the meter service life) and capital repayment period. An overview of lessons learned and conclusions from the case studies are provided in Chapters 8 and 9 of the report.