A contingent valuation of river water inflows into the Swartkops, Kariega, Mngazi and Mngazana Estuaries in the Eastern Cape
- Authors: Mlangeni, Moses Mbendela
- Date: 2007
- Subjects: Contingent valuation -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Swartkops Estuary (Eastern Cape, South Africa) , Kariega Estuary (Eastern Cape, South Africa) , Mngazi Estuary (Eastern Cape, South Africa) , Mngazana Estuary (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9004 , http://hdl.handle.net/10948/569 , http://hdl.handle.net/10948/d1011690 , Contingent valuation -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Swartkops Estuary (Eastern Cape, South Africa) , Kariega Estuary (Eastern Cape, South Africa) , Mngazi Estuary (Eastern Cape, South Africa) , Mngazana Estuary (Eastern Cape, South Africa)
- Description: Many South African estuaries are currently believed to be generating lower levels of services than they used to in the past due to substantially reduced inflow of river water, among other reasons. The basis by which river water is allocated in South Africa has had to be re-examined. Local authorities are now required to integrate into their development planning sensitivity to the ways estuaries work; the relevant legislation being the Municipal Systems Act No. 32 of 2000. Sound water resource management requires that the benefits and costs of different water allocations be compared and an optimum determined. The Contingent Valuation Method (CVM) is used in this study to estimate the benefits of changing allocations of river water into estuaries. This study builds on a CVM pilot project done at the Keurbooms Estuary in the Southern Cape in year 2000 (Du Preez, 2002). Further CVM studies were conducted at the Knysna, Groot Brak and Klein Brak estuaries (Dimopolous, 2004). The CVM is a valuation technique based on answers given to carefully formulated questions on what people are willing to pay for specified changes of freshwater inflows into estuaries. The CVM depends on there being a close correspondence between expressed answers given to hypothetical questions and voluntary exchanges in competitive markets that would be entered into if money did actually change hands. The fact that it has proved very difficult to establish this correspondence has led to CVM being subject to criticism. However, many aspects of this criticism have been addressed in the form of methods to reduce biases, and the application of the technique has grown steadily in popularity during the past 25 years. Four estuaries, the Swartkops, Kariega, Mngazi and Mngazana, were surveyed as part of this study in order to determine users’ willingness to pay (WTP) for changes in freshwater inflows. Considerable research time was devoted at the estuaries getting to know how things worked around and in the estuaries. The Swartkops estuary is a permanently open system within the Nelson Mandela Bay metropolitan area. The estuary has the third largest salt marsh in South Africa. Its banks are highly developed with residential and industrial property and it is heavily used for both recreation and subsistence fishing by locals. The Kariega estuary is located near the semi-rural town of Kenton-on-sea, between Port Elizabeth and East London. Although it is permanently open, the Kariega estuary has very low inflows of river water. It is mainly used by retired pensioners living in holiday houses at Kenton-on-sea. The Kariega is not heavily used for recreation and subsistence fishing, except during holidays and the festive season because of its proximity to other estuaries such as the Bushmans and the Kleinemond. The Mngazi and the Mngazana estuaries are located in the Wild Coast area of the Eastern Cape, in the Port St Johns Municipal district. The Mngazi is a temporarily open/closed system which does not have high botanical ratings, although it is heavily used by visitors to the well known Mngazi River Bungalows, a highly rated hotel near the mouth of the Mngazi River. The Mngazana estuary is a permanently open system renowned for its Mangrove forests and excellent fishing spots. Both the Mngazi and Mngazana estuaries are located in rural areas and are heavily used by local village residents for subsistence purposes.
- Full Text:
- Date Issued: 2007
- Authors: Mlangeni, Moses Mbendela
- Date: 2007
- Subjects: Contingent valuation -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Swartkops Estuary (Eastern Cape, South Africa) , Kariega Estuary (Eastern Cape, South Africa) , Mngazi Estuary (Eastern Cape, South Africa) , Mngazana Estuary (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9004 , http://hdl.handle.net/10948/569 , http://hdl.handle.net/10948/d1011690 , Contingent valuation -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Swartkops Estuary (Eastern Cape, South Africa) , Kariega Estuary (Eastern Cape, South Africa) , Mngazi Estuary (Eastern Cape, South Africa) , Mngazana Estuary (Eastern Cape, South Africa)
- Description: Many South African estuaries are currently believed to be generating lower levels of services than they used to in the past due to substantially reduced inflow of river water, among other reasons. The basis by which river water is allocated in South Africa has had to be re-examined. Local authorities are now required to integrate into their development planning sensitivity to the ways estuaries work; the relevant legislation being the Municipal Systems Act No. 32 of 2000. Sound water resource management requires that the benefits and costs of different water allocations be compared and an optimum determined. The Contingent Valuation Method (CVM) is used in this study to estimate the benefits of changing allocations of river water into estuaries. This study builds on a CVM pilot project done at the Keurbooms Estuary in the Southern Cape in year 2000 (Du Preez, 2002). Further CVM studies were conducted at the Knysna, Groot Brak and Klein Brak estuaries (Dimopolous, 2004). The CVM is a valuation technique based on answers given to carefully formulated questions on what people are willing to pay for specified changes of freshwater inflows into estuaries. The CVM depends on there being a close correspondence between expressed answers given to hypothetical questions and voluntary exchanges in competitive markets that would be entered into if money did actually change hands. The fact that it has proved very difficult to establish this correspondence has led to CVM being subject to criticism. However, many aspects of this criticism have been addressed in the form of methods to reduce biases, and the application of the technique has grown steadily in popularity during the past 25 years. Four estuaries, the Swartkops, Kariega, Mngazi and Mngazana, were surveyed as part of this study in order to determine users’ willingness to pay (WTP) for changes in freshwater inflows. Considerable research time was devoted at the estuaries getting to know how things worked around and in the estuaries. The Swartkops estuary is a permanently open system within the Nelson Mandela Bay metropolitan area. The estuary has the third largest salt marsh in South Africa. Its banks are highly developed with residential and industrial property and it is heavily used for both recreation and subsistence fishing by locals. The Kariega estuary is located near the semi-rural town of Kenton-on-sea, between Port Elizabeth and East London. Although it is permanently open, the Kariega estuary has very low inflows of river water. It is mainly used by retired pensioners living in holiday houses at Kenton-on-sea. The Kariega is not heavily used for recreation and subsistence fishing, except during holidays and the festive season because of its proximity to other estuaries such as the Bushmans and the Kleinemond. The Mngazi and the Mngazana estuaries are located in the Wild Coast area of the Eastern Cape, in the Port St Johns Municipal district. The Mngazi is a temporarily open/closed system which does not have high botanical ratings, although it is heavily used by visitors to the well known Mngazi River Bungalows, a highly rated hotel near the mouth of the Mngazi River. The Mngazana estuary is a permanently open system renowned for its Mangrove forests and excellent fishing spots. Both the Mngazi and Mngazana estuaries are located in rural areas and are heavily used by local village residents for subsistence purposes.
- Full Text:
- Date Issued: 2007
The design and assessment of an integrated municipal waste beneficiation facility : towards improved sewage sludge management in developing countries
- Authors: Keirungi, Juliana
- Date: 2007
- Subjects: Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4755 , http://hdl.handle.net/10962/d1007138 , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Description: This research aimed to firstly confirm the hypothesis that the current management of sewage sludge generated during the treatment of wastewater in the Eastern Cape Province of South Africa is poor and, as such, this material poses a threat to local environmental and human health. Secondly, through a rational design approach, the current research also aimed to design and assess the suitability of a novel integrated process incorporating appropriate technologies for improved sewage sludge management. The lack of an appropriate tool for the assessment of the integrated process necessitated the development of an appropriate technology assessment (TA) methodology based on environmental, technical, social and economic criteria. A combination of informal participatory methods such as semi-structured interviews and formal research methods including questionnaires, risk assessment exercises and laboratory analyses were used. Based on the above it was estimated that 116 tons dry sludge were generated in the province per day and that the concentration of heavy metals present in the sludge was generally within the limits for reuse on agricultural land. Furthermore the sludge from all sample sewage treatment works (STWs) was found to be free of any detectable pathogens. Despite the above, a preliminary risk assessment and chemical analysis revealed that existing sludge management practices at sample STWs posed a threat to the environment, particularly to water resources and exacerbated the problems associated with the discharge of poorly treated municipal wastewater. The root causes of the poor sludge management were considered to be a lack of non-regulatory incentives and financial resources. Highly integrated ecologically engineered systems were thought to offer a solution to the dual problem of poor sludge management and municipal effluent treatment, while providing necessary economic incentives. To facilitate the design of a system appropriate to local conditions, it was necessary to first develop a rational design methodology, which incorporated a detailed TA step. The result of the design process was an Integrated Waste Beneficiation Facility (IWBF) that incorporated a number of process units comprised of appropriate technologies including composting, vermicomposting, algal ponding technology and aquaculture. A detailed TA indicated that the benefits of the proposed IWBF would, at the majority of sample sites, outweigh the potential negative impacts and it was thus recommended that investigations should continue on pilot-scale facilities. Furthermore, although the proposed TA based on four sustainability criteria categories was thought to provide a more accurate assessment of the true sustainability of a technology, the acquisition of information was problematic highlighting the need to re-think current TA methodologies and to address associated constraints allowing the tool to be used and fully comprehensive.
- Full Text:
- Date Issued: 2007
- Authors: Keirungi, Juliana
- Date: 2007
- Subjects: Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4755 , http://hdl.handle.net/10962/d1007138 , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage sludge -- South Africa -- Eastern Cape -- Management , Water quality management -- South Africa -- Eastern Cape
- Description: This research aimed to firstly confirm the hypothesis that the current management of sewage sludge generated during the treatment of wastewater in the Eastern Cape Province of South Africa is poor and, as such, this material poses a threat to local environmental and human health. Secondly, through a rational design approach, the current research also aimed to design and assess the suitability of a novel integrated process incorporating appropriate technologies for improved sewage sludge management. The lack of an appropriate tool for the assessment of the integrated process necessitated the development of an appropriate technology assessment (TA) methodology based on environmental, technical, social and economic criteria. A combination of informal participatory methods such as semi-structured interviews and formal research methods including questionnaires, risk assessment exercises and laboratory analyses were used. Based on the above it was estimated that 116 tons dry sludge were generated in the province per day and that the concentration of heavy metals present in the sludge was generally within the limits for reuse on agricultural land. Furthermore the sludge from all sample sewage treatment works (STWs) was found to be free of any detectable pathogens. Despite the above, a preliminary risk assessment and chemical analysis revealed that existing sludge management practices at sample STWs posed a threat to the environment, particularly to water resources and exacerbated the problems associated with the discharge of poorly treated municipal wastewater. The root causes of the poor sludge management were considered to be a lack of non-regulatory incentives and financial resources. Highly integrated ecologically engineered systems were thought to offer a solution to the dual problem of poor sludge management and municipal effluent treatment, while providing necessary economic incentives. To facilitate the design of a system appropriate to local conditions, it was necessary to first develop a rational design methodology, which incorporated a detailed TA step. The result of the design process was an Integrated Waste Beneficiation Facility (IWBF) that incorporated a number of process units comprised of appropriate technologies including composting, vermicomposting, algal ponding technology and aquaculture. A detailed TA indicated that the benefits of the proposed IWBF would, at the majority of sample sites, outweigh the potential negative impacts and it was thus recommended that investigations should continue on pilot-scale facilities. Furthermore, although the proposed TA based on four sustainability criteria categories was thought to provide a more accurate assessment of the true sustainability of a technology, the acquisition of information was problematic highlighting the need to re-think current TA methodologies and to address associated constraints allowing the tool to be used and fully comprehensive.
- Full Text:
- Date Issued: 2007
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