Page 1. i DECLARATION I declare that this thesis is my own, unaided work. It is being submitted f... more Page 1. i DECLARATION I declare that this thesis is my own, unaided work. It is being submitted for the Degree of Doctor of Philosophy in the University of the Witwatersrand, Johannesburg. It has not been submitted before for any degree or examination in any other University. ...
Stormwater drainage systems discharging non-storm water add substantial pollution to urban waterc... more Stormwater drainage systems discharging non-storm water add substantial pollution to urban watercourses, with negative impacts to water quality and aquatic ecosystems. Thus, the elimination of these discharges can be a highly effective non-structural best management practice (BMP) to improve water quality. This study aimed to guide local municipalities whose task it is to control polluted non-storm water entries into the stormwater drainage system. The study evaluated procedures, methodologies and techniques of illegal discharge detection and elimination (IDDE) programme components, as practised internationally, and applied these in a local condition to verify their feasibility and challenges. The paper provides guidance to identify and prioritise investigations for controlling illegal discharges into stormwater drainage systems. Challenges encountered in the study included lack of legal authority to undertake inspection, surveillance and monitoring at private and corporate properti...
Discharges from informal settlements cause numerous adverse water quality impacts on urban areas ... more Discharges from informal settlements cause numerous adverse water quality impacts on urban areas and on receiving waters. These problems reflect local conditions with respect to economic development, level of environmental protection (including the associated infrastructure), institutional arrangements and public awareness. Development of comprehensive tools for selection of drainage management interventions, even at planning levels, is still at its early stages in South Africa. Municipalities in South Africa face many challenges in identifying, assessing and selecting the right interventions and/or strategies to address the impacts of land use on receiving waters. A spreadsheet-based model was developed in this study specifically to assist in identifying, selecting and evaluating interventions to manage storm-and grey-water quality. The model also consists of modules: to quantify water quality management objectives (load reduction targets) of pollutants of concern, to formulate implementation strategies by combining different mixes of interventions at different levels of implementation, and to cost and select the optimum management strategy. In the Alexandra settlement investigated, the identified interventions to achieve management objectives optimally consist of educational programmes, erosion and sediment control, street sweeping, removal of sanitation system overflows, impervious cover reduction, downspout disconnections, removal of illicit connections to storm drains, establishment of riparian buffers, use of rainwater tanks and exfiltration systems.
Page 1. i DECLARATION I declare that this thesis is my own, unaided work. It is being submitted f... more Page 1. i DECLARATION I declare that this thesis is my own, unaided work. It is being submitted for the Degree of Doctor of Philosophy in the University of the Witwatersrand, Johannesburg. It has not been submitted before for any degree or examination in any other University. ...
Stormwater drainage systems discharging non-storm water add substantial pollution to urban waterc... more Stormwater drainage systems discharging non-storm water add substantial pollution to urban watercourses, with negative impacts to water quality and aquatic ecosystems. Thus, the elimination of these discharges can be a highly effective non-structural best management practice (BMP) to improve water quality. This study aimed to guide local municipalities whose task it is to control polluted non-storm water entries into the stormwater drainage system. The study evaluated procedures, methodologies and techniques of illegal discharge detection and elimination (IDDE) programme components, as practised internationally, and applied these in a local condition to verify their feasibility and challenges. The paper provides guidance to identify and prioritise investigations for controlling illegal discharges into stormwater drainage systems. Challenges encountered in the study included lack of legal authority to undertake inspection, surveillance and monitoring at private and corporate properti...
Discharges from informal settlements cause numerous adverse water quality impacts on urban areas ... more Discharges from informal settlements cause numerous adverse water quality impacts on urban areas and on receiving waters. These problems reflect local conditions with respect to economic development, level of environmental protection (including the associated infrastructure), institutional arrangements and public awareness. Development of comprehensive tools for selection of drainage management interventions, even at planning levels, is still at its early stages in South Africa. Municipalities in South Africa face many challenges in identifying, assessing and selecting the right interventions and/or strategies to address the impacts of land use on receiving waters. A spreadsheet-based model was developed in this study specifically to assist in identifying, selecting and evaluating interventions to manage storm-and grey-water quality. The model also consists of modules: to quantify water quality management objectives (load reduction targets) of pollutants of concern, to formulate implementation strategies by combining different mixes of interventions at different levels of implementation, and to cost and select the optimum management strategy. In the Alexandra settlement investigated, the identified interventions to achieve management objectives optimally consist of educational programmes, erosion and sediment control, street sweeping, removal of sanitation system overflows, impervious cover reduction, downspout disconnections, removal of illicit connections to storm drains, establishment of riparian buffers, use of rainwater tanks and exfiltration systems.
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Papers by Yaw Owusu-Asante