Framework for assessing the viability of implementing dual water reticulation systems in South Africa

In many settlements across the world (e.g. Pimpama Coomera and Mawson Lakes – Australia, Hong Kong – China, Majuro – Marshall Islands, Tarawa – Kiribati, and Windhoek – Namibia), dual water reticulation systems have been implemented in response to increasing water demands and decreasing freshwater availability. A dual water reticulation system comprises separate pipes that supply different water qualities to the end consumer. A set of pipes supply potable water while another set of pipes supply non-potable water. The non-potable water is targeted at meeting water requirements traditionally met using potable water (e.g. toilet and urinal flushing, landscaping irrigation, and industrial cooling). This therefore frees potable water to be used for previously unmet or increasing potable water requirements. For several reasons including the dearth of relevant national regulatory and guideline documents, consumer and decision-maker perceptions, ignorance, and appropriate decision-making tools, the use of dual water reticulation systems in South Africa has been limited. The aim of this study was therefore to develop a decision-making framework, using robust criteria, for assessing the viability of implementing dual systems in South Africa. This aim was achieved through undertaking literature reviews on the subject, an investigation of non-potable water consumers’ and decision-makers’ perceptions using questionnaires, and the actual development of a framework using data obtained from the literature review and questionnaires. The questionnaires were developed using seven key issues i.e. public health and safety, economics, technical feasibility, legislation/regulations and guidelines, organisational capacity, social acceptance, and public education. The various aspects of the Triple Bottom Line of sustainability (i.e. economic, environmental and social) provided structure to the framework while the Triple Bottom Line approach was utilised in the assessment of the different criteria

Prevalence Of Tsetse Fly And Bovine Trypanosomosis In The Biological Control Of Tsetse Fly Project (Bicot) Within Afia Local Government Area Of Nasarawa State, Nigeria

The prevalence of tsetse fly and bovine trypanosomosis was studied in the biological control of tsetse fly project (BICOT) area within Lafia Local Government Area of Nasarawa state, Nigeria between May and November 2000. The project area, covering approximately 1500 km2 was virtually freed of Glossina palpalis palpalis and to some extent G tachinoides by Dec. 1984. By 1987, however, sterile male releases were suspended and remained so till the time of this study due to lack of funding. Ten biconical traps were set at an interval of 25 meters along each river/stream in the study area. In all, 466 flies were caught out of which 454 were G.p palpalis while the remaining 12 were G.tachinoides. The result of the dissection of the insects showed that 9 (1.9%) of tsetse flies caught were positive for Trypanosoma vivax. All infected flies were G.p palpalis. Also blood samples were collected from 200 cattle in the abattoir and 200 in the sedentary cattle in the area. The blood samples were examined using standard parasitological techniques. The result showed that, in sedentary cattle, 18(9%) were positive for trypanosomes while in the abattoir 21(10.5%) were positive for trypanosomes. There was however no significant difference (p > 0.05) between the numbers of cases defected in sedentary cattle and abattoir cattle. Most of the infections in sedentary cattle (67%) and abattoir cattle (81%) were due to T. congolense. Keywords: Tsetse fly ,bovine trypanosomosis, biological control, LafiaJournal of Agriculture and Social Research Vol. 8 (1) 2008: pp. 8-1

An improved area-based guideline for domestic water demand estimation in South Africa

Increased infrastructural development and potable water consumption have highlighted the importance of accurate waterdemand estimates for effective municipal water services infrastructure planning and design. In the light of evolving water consumption trends, the current guideline for municipal water demand estimation, published in 1983, needs to be revised. This study investigated, using regression analyses, the combined effect of various socio-economic and climatic parameters on municipal water consumption with the objective of determining the dominant influencing parameters and suggesting a new guideline for water-demand estimation. To this end, an initial database comprising more than 2.5 x106 metered water consumption records extracted from 48 municipal treasury databases, which are located within 5 out of the 7 South African water regions was analysed. Each of the 48 municipal treasury databases spanned a period of at least 12 months. The final amalgamated database, after rigorous cleaning and filtering, comprised 1 091 685 consumption records. Single variable and stepwise multiple variable regression analyses were utilised. Results show that stand area, stand value and geographical location are the dominant parameters influencing municipal water consumption, with stand area and stand value positively correlated to water consumption. In suggesting a new municipal water-demand estimation guideline, these three parameters were considered. Stand value, however, fell away as a reliable parameter for estimating water consumption because of the inconsistent basis for predicting stand values due to the constant fluctuations in the value of property, and municipal valuations that often become outdated. Inland and coastal geographical locations exhibited different consumption patterns, with coastal stands of the same stand area and stand value consistently consuming less water than inland stands. These should therefore be treated separately in any design guideline. Stand area then became the best parameter on which to base water-demand estimations. A single guideline curve is therefore proposed which gives various confidence limits for estimating water demand in South Africa, based on stand area.Keywords: domestic water demand estimation, area-based guidelin

Trypanosoma vivax Infections: Pushing Ahead with Mouse Models for the Study of Nagana. II. Immunobiological Dysfunctions

Trypanosoma vivax is the main species involved in trypanosomosis, but very little is known about the immunobiology of the infective process caused by this parasite. Recently we undertook to further characterize the main parasitological, haematological and pathological characteristics of mouse models of T. vivax infection and noted severe anemia and thrombocytopenia coincident with rising parasitemia. To gain more insight into the organism's immunobiology, we studied lymphocyte populations in central (bone marrow) and peripherical (spleen and blood) tissues following mouse infection with T. vivax and showed that the immune system apparatus is affected both quantitatively and qualitatively. More precisely, after an initial increase that primarily involves CD4+ T cells and macrophages, the number of splenic B cells decreases in a step-wise manner. Our results show that while infection triggers the activation and proliferation of Hematopoietic Stem Cells, Granulocyte-Monocyte, Common Myeloid and Megacaryocyte Erythrocyte progenitors decrease in number in the course of the infection. An in-depth analysis of B-cell progenitors also indicated that maturation of pro-B into pre-B precursors seems to be compromised. This interferes with the mature B cell dynamics and renewal in the periphery. Altogether, our results show that T. vivax induces profound immunological alterations in myeloid and lymphoid progenitors which may prevent adequate control of T. vivax trypanosomosis

Undergraduate engineering training through institutional collaboration in the Southern African region

The University of the Witwatersrand (Wits) and The University of Namibia (UNAM) signed an Agreement of Co-operation (AOC) in 2000. This agreement, which formalised an existing informal collaboration, was primarily targeted at facilitating the transfer of potential Unam undergraduate engineering students to pursue engineering studies at the WITS Faculty of Engineering as well as improving staff collaboration in research and teaching. Students from UNAM's pre-engineering programme and science departments have been beneficiaries of this agreement. Four years later, an evaluation of the collaboration reveals critical issues vis-aÁ-vis decreasing student enrolments, unimpressive student graduation rates, and financial and operational complexities affecting student mobility ± all of which have institutional as well as regional implications. This paper presents highlights and pertinent lessons of the collaboration, and recommendations for similar collaboration in the Southern African region both at an institutional and regional level. As a whole, the paper uses the Wits experience to extrapolate principles and strategic issues facing institutions involved in academic collaboration and crossborder movement of students within the Southern Africa region. South African Journal of Higher Education Vol. 19 (4) 2005: pp.735-75

An evaluation of the primary South African standard and guideline for the provision of water for firefighting

In South Africa, as is mostly the norm globally, national legislation and guidelines specify that potable water distribution networks maintain the capacity to provide specified quantities of water for firefighting. This paper addresses the question: is the South African standard and guideline pertaining to fire-flow provision appropriate for firefighting and do these ensure the most efficient balance between providing sufficient fire protection and promoting sustainable water use? In answering this question, this study: (i) reviewed national and international design standards and guidelines; and (ii) captured and analysed 10 years of billable fire incident reports representing 3 859 fire events within the City of Johannesburg. Highlights from the study include: inconsistencies in categories when comparing the SANS 10090 and The Red Book fire tables and violations (in The Red Book) of stipulated Minimum Fire Flows; over the 10 year period, 75% of fire incidents within the City of Johannesburg were extinguished using less than 6.6 kL of water – less than the capacity (6.9 kL) of the City’s conventional pumping tanker during the period; 99.9% of fire incidents within the City were quenched using an average fire flow rate of less than 1 200 L/min, which is the minimum hydrant flow rate for the lowest fire risk category in SANS 10090; and peak fire occurrence did not correspond with typical peak residential water use. Recommendations are proffered in respect of the above

CCWi2017: F64 'ANALYSIS OF SHOWER WATER USE AND TEMPERATURE AT A SOUTH AFRICAN UNIVERSITY CAMPUS'

Earlier research has underlined that household end-uses form building blocks of the residential water demand pattern. Numerous end-use studies have been presented in the past, but none have reported on shower end-uses at Universities in South Africa. This research focuses on shower water use, as part of the first detailed end-use field study conducted in South Africa. An extensive desktop study was conducted regarding South African end-uses, focusing on shower use. Shower flow rate was physically measured under different conditions, while actual shower duration for the same showers was derived from water temperatures recorded over two periods of 5 days each, at 1 min frequency. The changes in temperature were used to estimate actual shower duration and event start times. The total shower event volume was stochastically determined by using Monte Carlo analysis. The average shower duration of the 759 shower events identified as part of this study was 9 min and 33 sec, with a flow rate of 8.7 L/min. The average shower event volume was 83 L/event