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A basic model to predict water quality changes in the Vaal DamKneidinger, Tanya Michaela 06 February 2012 (has links)
M.Sc. / The Vaal Dam (South Africa) and its tributaries have been extensively affected by domestic, mining, agricultural and industrial activities, as well as the release of effluents. These practices have contributed to large-scale algal blooms that have caused serious ecological, aesthetic, water purification and water distribution problems. This study addresses the need to develop a system that enables forecasts to be made regarding potential changes in the water quality ofthe Vaal Dam, especially with regards to predicting algal blooms. The primary aim was to develop a simple spreadsheet based model to predict the occurrence of algal blooms and other water quality changes in the Vaal Dam, making use of environmental parameters recorded at several sites located upstream of the Rand Water intake point at the Vaal Dam wall. Accurately forecasting sudden changes in water quality would enable proactive resource management, ensuring that Rand Water maintains a high standard of potable water delivered to its customers. Statistical model equations, to predict the concentrations of various water quality constituents, were obtained by step-wise regression analysis. These equations were then entered into MS-Excel spreadsheets. This allowed the input of environmental data and the subsequent calculation of the predicted value. This also allowed for the manipulation of various parameters to forecast the effects any changing values will have on the water quality. These "if-then'' scenarios would be of considerable use in implementing management measures to achieve the desired water quality. The performance of the model was statistically tested to determine if it adequately represents the study system. The models to determine chlorophyll-a concentration and several other water quality constituents proved to be fairly accurate in representing the study system. However, the model to predict nitrate concentrations did not perform satisfactorily. The limitations in model performance were attributed to the low frequency of water quality sampling and the effects of undetermined variables not represented by the water quality parameters selected for model development. The model is compact, does not require specialised software, and is applicable in practice. The predictive and scenario forecasting abilities make this model useful for the identification, monitoring and prediction of changes or trends in water quality over time. The benefits arising from this model will thus contribute to more cost efficient water treatment, improved response times to algal blooms, improved decision-making and proactive water resource management.
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Water loss reduction in community water supply schemes: a case study investigating the identification of effective techniquesNthutang, Pholo 25 March 2010 (has links)
M.Tech. / The Water Services Authorities in South africa are currently responsible for the management and operation of rural water supply in the country.Many of these comunity water supply schemes are in poor conditions due to lack of proper operation, maintenance, poor design and/or poor construction with the result that they experience serious water losses through physical losses(leakage)and apparent losses, and often fail to meet the consumer's demand during peak periods.Indications are that substantial quantities of water are lost in the systems due to leakage, wasteful use, illegal connections and meter errors. As a result of these problems, the levels of service delivery are often very poor leading to low cost recovery resulting in water services institutions becoming ineffective and inefficient businesses. The investigation attempted to identify effective techniques and/or strategies for water loss reduction in Dinokana Village (Central District Municipality). The study identified and defined various procedures/methodologies for managing Non Revenue Water in community water supply schemes. Some of the strategies developed from the findings of this research have been implemented with a view of quantitatively verifying their effectiveness.
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Improved access to small community drinking water supply systems and its effect on the probability of bacterial infection posed by water in household drinking water containersMokoena, Matodzi Michael 08 April 2010 (has links)
M. Tech. / The study assessed the risk of infection introduced by containers in which households collect water from different sources. The study area was in rural villages in the Vhembe region of the Limpopo Province. Each village had its own unique water sources consisting mainly of untreated ground waters and untreated surface waters. Randomly selected household members use their containers to collect water from these different sources. Two of the three villages received new small water supply systems within the study period, proving the villagers with water of good health-related microbial quality. The remaining village continued to use contaminated water from their untreated surface water sources. The water supply intervention in two of the three villages provided the opportunity to assess the impact these interventions would have on the risk of infection i.e. whether the risk could be reduced for the villagers no having access to good quality water. A customized quantitative microbial risk assessment was done based on the health-related quality of the water that people ingested before and after the intervention. This assessment was based on exposure of, consequence to and impact on an individual water consumer. Exposure included variables such as daily quantities of unheated drinking water consumed per individual (in litres) available at the point of use (in the dwelling) for ingestion, numbers of diarrhoeagenic E. coli (Dec) per litre in water sampled from containers derived from water samples positive for indicator E. coli and daily doses of DEc per litre ingested by an individual in the target population. Consequence was assessed by calculating the probability of infection per day from diarrhoeagenic E. coli for an individual and from there the annual infection per individual. The impact of the small water supply system was determined by assessing changes in annual individual risk of infection from before to after the interventions per village. In terms of daily water volumes consumed per individual, there were no significant differences in consumption amongst the three villages. At 1.26 ℓcd (at the upper limit of the 95% confidence interval) the consumption was slightly higher than the one litre suggested by WHO 2003. The container water collected from sources before the intervention in the two villages was significantly more contaminated by indicator E. coli (iEc) and diarrhoeagenic E. coli (DEc) than their container waters after the intervention. In terms of impact, the risk of infections was substantially reduced by the interventions. For Village 1 the risk of infection was reduced from 646 infections to 135 infections per 10,000 of the population. If these are converted to 10% as disease manifesting, then there could have been 65 cases of enteric disease attributable to water before the intervention, which was then reduced to 14 cases after the intervention. For Village 2 the population risk was reduced from 110 to 67 cases after the intervention. For Village 3 the population risk remained at 2,778 infections or 278 cases of enteric waterborne disease because of their continued use of untreated water. The study findings indicated that for Village 1, the population risk of infection would be 135 infections per 10,000, for Village 2 it would be 167 and for Village 3 - 234. If the hypothetical conversion rate of one case of enteric waterborne disease for every 10 infections of Howard et al. (2006) is used, then this would mean 14 cases of disease per 10,000 for the population for Village 1, 17 cases for Village 2 and 24 cases for Village 3. Relating this to the WHO (2003) suggestion of one case per 1,000 as an acceptable, it would mean 1.3 cases for Village 1, 1.7 for Village 2 and 2.4 for Village 3. For Village 1 the risk of contracting waterborne enteric disease was close to acceptable, but not at all acceptable for the other two villages, even for Village group 2 after the intervention. The water system in Village 2 failed often during the study which was probably the cause of the persistently higher risk of disease. It can be concluded that providing a well maintained small water supply system reduced the risk to and maintained it at an acceptable level. Table
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An analysis of water pricing and consumption variations within the occupied West BankMcIntyre, Graham 05 1900 (has links)
International disputes over access to water resources can act as a catalyst for conflict or cooperation amongst nations. In the case of Israel and the occupied West Bank, water conflict further exacerbates preexisting political tension, and yet a peaceful and equitable solution between these countries could spark further negotiation.
Within this context, the Palestinian Hydrology Group conducted a water questionnaire amongst Palestinian households in the occupied West Bank in 2001. The aim of the PHG’s survey was to investigate which water management system would be the most suitable in terms of equity, cost-recovery, and long-term development of the resource. Ultimately the water pricing system that was recommended was an increasing block-tariff system, which prioritizes the delivery of necessary amounts of water used for basic needs amongst all users before further allocating water to other uses. However, most of the work conducted by the PHG was qualitative and based entirely on descriptive statistics. Analysis regarding the relationships between water pricing, water consumption, and water needs, and how these relationships change over different scales, was not present in the final report.
The purpose of this thesis to continue the research conducted by the PHG by analyzing the water questionnaire database as a means to further advise and direct water services within the occupied West Bank. In order to discern relationships between seasonal patterns of water pricing and consumption, an in-depth analysis of that data was conducted. In addition, perceived water needs were also examined. This analysis was performed at a variety of scales, including amongst districts, average monthly income levels, and connection/non-connection to a water network.
Results indicate that some districts in the occupied West Bank are comparatively under-serviced. The economically poor district of Jenin seems to be in greatest need of stabilized and equitable water resources, followed by Hebron, Nablus and Ramallah. It was also observed that those within lower income brackets bear a disproportionate share of pricing fluctuations and, not surprisingly, low consumption levels. Connection/non-connection to a water network indicates that not only is consumption amongst non-connected households significantly low, but also that the difference between perceived water needs and water consumption is much greater than amongst connected households. This thesis supports the PHG’s recommendation for an increasing block-tariff system, since regression analysis indicates inequitable distribution and pricing amongst districts and income levels. / Arts, Faculty of / Geography, Department of / Graduate
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Feasibility of groundwater abstraction and treatment for urban water supplyBlignault, Samantha Paige January 2020 (has links)
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.
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Case study review of advanced water metering applications in South AfricaNgabirano, Lillian January 2017 (has links)
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.
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Spatial Variations in Tap Water Isotopes Across Canada: Tracing Water from Precipitation to Distribution and Assess Regional Water ResourcesBhuiyan, Shelina Akter 19 May 2022 (has links)
Tap water supply is an essential resource for human societies. However with increasing water use and global warming, this resource needs to be monitored and managed sustainably. Here we use stable isotopes to identify potential issues associated with tap water resources in Canada. We analyze isotopes of 576 tap water samples collected from across Canada and classified them based on their supply sources including groundwater (TapGroundwater), river (TapRiver) and lake (TapLake). We found, isotopic values in tap water correlate strongly with those predicted in local precipitation across Canada, suggesting precipitation is the parent source of tap water. However, this correlation is stronger for TapGroundwater and TapRiver than TapLake. To explain this difference, we constructed a series of water balance models to predict isotopic values of surface water across Canada validated against Canadian rivers isotopes data. We then compared the tap water isotopic values to those predicted in local surface water, which improved the predictability of TapRiver and TapLake but not TapGroundwater. We suggest, TapGroundwater usually reflects isotopic values of annually averaged precipitation whereas TapRiver and TapLake reflect post-precipitation processes. We used the residuals between our observed and predicted isotope data to assess regional sources and processes influencing tap water isotopes across Canada. Regionally, snow/glacier melt from the Rockies contributes to groundwater recharge across Western Canada as well as to some rivers and lakes in Alberta and British Columbia. Also, tap water are highly evaporated across Western Canada irrespective of their sources. Across the Great Lakes and East Coast regions, lakes undergo high evaporative losses. Also, many localities in the East Coast pump and store groundwater in small lakes or ponds exposing them to evaporation. Our data and models provide a baseline for isotope monitoring of tap water resources and isotope forensic studies across Canada.
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Bacterial Survey of Representative Denton County Wells with Special Reference to SanitationRoberts, Sally Stevens 06 1900 (has links)
This thesis aimed to study the seventy-two representative wells of Denton County and to determine the possibilities of infection with typhoid organism. The sanitary survey and the test for Colon-Aerogenes bacteria show that 55% of the 72 wells studied are unsanitary, 27% are sanitary, and 18% are doubtful.
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Impact of Water Management Strategies on Populations of Rice Water Weevil, (Coleoptera: Curculionidae)Kelly, Franklin Read 03 May 2019 (has links)
Experiments were conducted to determine the impact of water management strategies on populations of rice water weevil, Lissorhoptrus oryzophilus Kuschel. One experiment was conducted at the Delta Research and Extension Center during 2017 and 2018. The performance of chlorantraniliprole and thiamethoxam was evaluated in combination with flood removal of a field as a cultural control tactic for rice water weevil. Seed treatments significantly reduced rice water weevil populations at the prelood sample timing, only chlorantraniliprole reduced populations at the post-drainage sample timing. Overall, flood removal had little impact on rice water weevil management. An experiment was also conducted to determine the spatial and temporal distribution of rice water weevil larvae within a furrow irrigated rice production system. This experiment was established across eleven grower fields in major rice producing counties across the Mississippi Delta from 2017 to 2018. Fields were divided into three zones based on free standing water within that portion of the field between irrigation events. Rice water weevil larval populations were reduced in portions of the field that did not remain at two of the three sample timings. An experiment was conducted at the Delta Research and Extension Center during 2017 to determine the impact of various water management strategies and insecticide seed treatments on rice water weevil populations. The –10 cm free standing water management strategy significantly reduced rice water weevil populations from the untreated control. Chlorantraniliprole had significantly higher yields across all water management strategies compared to other seed treatments and the untreated control.
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Water governance: a solution to all problemsFranks, Tom R. January 2006 (has links)
Yes / Water governance is a widely-used but ill-defined term. Our objective throughout this seminar series has been to analyse what it does mean and to question the consensus that seems to attach to it. In this paper for the final seminar I discuss what governance is not, I suggest what it is and I consider some propositions and issues that seem to have emerged from our meetings. In doing this, I appreciate that governance can mean different things to different people, but I suggest that, used in a specific way, it is a concept with particular value and significance for water development. / ESRC
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