published_or_final_version / Architecture / Master / Master of Science in Interdisciplinary Design and Management

Cheap water, massive federal subsidies and political clout have sustained rice farming in the lower Colorado River basin for decades, but now the industry is in a precarious situation. Drought, population growth upstream and economic boom in Austin are pushing out the practice because of increasing demand for Texas’ scarce water resources. The tightening supply of water raised questions about the sustainability of producing such a water intensive crop in the state. Drought has cut off the cheap water to farmers for three years, and a mobilized coalition of upper river basin interests is calling for a permanent end to subsidized water. It’s increasingly clear that the politics of water in a drought-prone future is likely to side with cities, where voters are heavily concentrated. Rice farmers have scrambled to adapt. Larger rice farms have switched to groundwater. Some farmers have swapped rice for corn, milo or soybeans to keep their income. Crop insurance, which made up for at least 55 percent of the money lost in drought, softened the blow for rice farmers. But revenues in rice-related industries in Wharton, Matagorda and Colorado counties have dropped sharply and some businesses have already packed it in. These new realities cast uncertainties throughout the lower river basin, where locals fear this way of life is disappearing. / text

3 pp. / Arizona Well Owner's Guide to Water Supply / To develop a ground water resource, it is necessary to design and construct a well capable of yielding a pumping rate compatible with the needs of the water well owner. Sufficient and sustained well yields are highly dependent on the characteristics of the aquifer, the construction of the well, and the maintenance of the well. Causes of low-yielding wells are explained and practices to restore well performance are recommended.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Sappi's Ngodwana integrated Kraft pulp and paper mill was used as case study for the application and evaluation of the water pinch technique. The technique of water pinch originates from energy pinch, but uses mass flow and contaminant concentration to identify water and effluent reduction opportunities. The classical meaning of pinch, as defmed by energy pinch has however been changed to a more modem meaning. Historically the terms water or energy pinch was used to refer to the points where two composite curves touched on energy or water graphs. This graphical meaning of pinch is gradually being replaced to refer to the optimal po int proposed by a numerical solver beyond which improvement of the water network is no longer possible for the given inputs. The water pinch technique was applied by means of a numerical solver that used mixed integer non-linear programming to optimise to the minimum cost for running the water network under investigation. The problem defmition was defined in terms of costs associated with the use of utilities, raw material, treatment facilities and process units. It was also possible to define factors such as environmental impact, corrosion, fouling, scaling, cooling tower treatment cost, legal risk etc in terms of a penalty cost. The water pinch technique has been refined in software packages that are user friendly, ca~ble of handling multi-contaminants and suitable for varying flows. The software package WaterPinch by Linnhoff March was used. The case study was applied on Ngodwana mill that has an already highly closed water system with effluent generation rates as low 20 kL per ton of pulp and paper. The pinch study included sodium, chloride, calcium, suspended solids and COD as contaminants. The study investigated different applications of the pinch technique. The following was concluded: • The mill's understanding of its current restrictions, ()l pinch points, of its water network was confirmed. No new pinch points have been identified of which the mill was not aware. This indicates that the mill was already highly knowledgeable about its water system. This was expected of a mill that has a very low specific-effluent-generation rate. Water pinch was unable to significantly improve on the effluent generation rate of the mill. • The pinch analysis has identified opportunities of mixing small quantities of waste streams into process water streams to replace fresh water. These changes can introduce minor water savings and new risks to the process that have to be understood better before implementation. • The mill has progressed far with the design and costing of a proposed effluent treatment plant (ERPl). The integration of this treatment plant into the water network was investigated using the pinch technique. The pinch solver suggested a totally different approach to the integration of the ERPI plant compared to design of the mill. The mill's design revolves around the treatment of low chloride streams in the ERPl plant and using of the treated water as make-up to the cooling towers. Sodium was recovered as raw material from the cooling towers' blow-down. Pinch proposed treatment of the high cWoride containing streams and returning the streams to users suitable of using high chloride water. The network proposed by mill's design generates 8.2 MLlday effluent less than the pinch proposal, and recovers sodium as raw material. The proposal presented by pinch is not recommended and points to the difficulty in simulating factors, such as raw material recovery, in a pinch analysis. • Users for the excess storm water were identified using water pinch and will be suitable for implementation. The mill has mwever decided on alternative sinks for the storm water based on considerations such as process inter-dependency, risks associated with contamination and general management philosophy for the different systems in the mill. These considerations could have been included into the pinch solver, but were not because it was of interest what the second best option would be. • The pinch investigation proved useful to confirm certain understandings of the mill. The investigation confirmed the difficulty of improving the water systems of the mill due to the fact that Ngodwana is already a highly closed and integrated mill. Numerous smaller process changes have been identified by the pinch solver and could be investigated further for smaller process improvements. • It i; recommended that pinch technology be applied again when the mill plans to make major process changes or expansions. It is also recommended to use water pinch on a more frequent basis in smaller sections of the mill or for other evaluations in the mill. As a group Sappi could benefit from the use of water pinch, especially in situations where the water network of the mill is not already water efficient. • The recommendations and conclusions in this report have not been subjected to technical and economical feasibility studies. Extensive further studies must be conducted before implementation of any of the results. Further studies must include impacts from process dynamics, long term effects, impacts from other contaminants that have not been simulated, etc. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.

This thesis examines the problems facing many of the rural water projects, especially in terms of their planning and implementation . There is a strong belief that water services in the rural areas are often not sustainable, and this is one of the major questions facing policy-makers over the last few years. The complexity of this problem has necessitated the development of a research project which will enable the assessment of various problems that become a barrier to the sustainability of water projects. The present study was carried out in Emfundweni administrative area of the Umzimkhulu district in the Eastern Cape Province. The methodology was based on a study of opinions, beliefs, ideas and realities as examined through research amongst community members, water department officials, local government staff in the form of the T.L.C's and engineers who were involved with the Emfundweni water project. One of the key aims of the study was to examine what problems affected the sustainability of water projects in rural areas, with the Emfundweni as a case study. The decision to include community members in the study is based on the fact that people involved in this water project hold their own perceptions, attitude and bias regarding what factors constituted problems that led to the lack of sustainability of the water project. The method that was used in the study allowed the researcher to compare the perceptions of the T.L.C's with those held by the community members engineers and water department officials. The findings supported the five hypotheses set out by the researcher in order to test the working model. / Thesis (M.A.)-University of Durban-Westville, 2003.

Delivering improved water services in small towns in low-income countries encompasses particular challenges. Often considered too large to be effectively community managed , small towns may also be too small, with too limited economies, to benefit from utility style professionalism and economies of scale. The most recent paradigm, that financially sustainable water services will be best achieved through the Demand Responsive Approach , has been complemented in Ghana, the focus of this study, through the development of a variety of management models, community, local government, national utility and private providers, to deliver DRA. Taking advantage of this unusual situation, in having a wide range of different functioning models in one country at the same time, this research has sought to investigate these management models with respect to effectiveness, equity, financial sustainability and efficiency of services delivery. However, the context in which all of these models operate relates to consumers effective demand, key to delivering a demand responsive approach. A second objective, necessary to validate any results relating to management models, has therefore been to investigate households actual demand for improved and alternative sources of water. Data for the research was gathered from examples of the four management models in use in Ghana, from eight small towns spread across the length and breadth of the country. The methodology incorporated key-informant interviews, user observations, household surveys and an analysis of relevant documents of operators and policy makers. The fieldwork was undertaken in two separate periods, designed to ensure that any effects of dry and wet season variations, which influence water supply delivery as well as demand, were adequately captured. The research found that none of the management models in use in small towns in Ghana could be considered to be significantly more effective than any other; overall, households demonstrated a limited demand for water supply with even this demand distributed among a number of sources, both formal, improved and alternative, traditional sources; this demand was not so much a function of affordability, rather a clear choice as to where to use limited resources mobile phone access absorbing three times the amount spent on water. Whilst certain management characteristics were found to make a difference, leadership in particular, no one model was able to influence the overarching water source effect, that is the cost of formal supply (surface water costing approximately three times more than ground water), relative to access to alternative, free supplies in the context of limited overall demand for water.

The purpose of this study is to develop a deeper understanding of the formation and performance of the international water management institutions operating in the Orange-Senqu basin shared between Lesotho, South Africa, Botswana, and Namibia. The research examines the influence of interstate interaction on adaptive capacity and the allocation of water and related benefits within the Orange-Senqu basin and provides explanations for how and why particular cooperative arrangements emerged and produce differential effects. By applying a structure-agent approach to regime analysis, this study draws attention to four key factors underpinning the formation and performance of the Orange-Senqu water governance regime: power asymmetry, problem structure (i.e., the combination of interest asymmetry and uncertainty), expert networks, and political context. The study demonstrates that each of these four factors provides important and complementary insight into the process of interaction of and the positive and negative effects produced by international water management institutions in the basin and opportunities for generating change. Among these factors, the study argues, power asymmetry and problem structure are critical for understanding transboundary water governance dynamics and identifying strategies for challenging the status quo.

Water colour is the naturally occurring yellow-brown 'tea like' discolouration which can be observed in freshwaters, and is typically composed of high molecular weight organic carbon. Water discolouration is a major problem for the water industry as over the past 30 years, water colour release has more than doubled, greatly increasing treatment costs and making land management a more feasible option for improving water quality. This project was developed in conjunction with Yorkshire Water Plc, to investigate the mechanisms of water colour production, and the implications that these mechanisms have for land management to improve water quality. In particular, the study aimed to identify the key relationships between drainage water quality and quantity, soil processes and vegetation type that are pivotal to the understanding of water discolouration.

The performance of a novel, visible light-driven photoelectrocatalytic (PEC) batch reactor employing tungsten trioxide (WO₃) as a photocatalyst was assessed by studying the degradation of selected model pollutants (2,4-DCP, chloroform) and the disinfection of a human bacterial pathogen (<i>E. coli </i>O157:H7). Overall efficacy of the batch reactor was assessed by combining biological toxicity assessment (biosensing) with conventional analytical chemistry. Photoelectrocatalytic degradation of the organoxenobiotics (2,4-DCP, chloroform) was monitored toxicologically by applying bacterial <i>lux</i>-marked biosensors and analytically by HPLC. The bacterial biosensor traced the removal of the target, model pollutants during degradation experiments, and also monitored changes in toxicity in the analyte of the PEC batch reactor caused by the possible appearance/disappearance of toxic transient intermediates derived from the breakdown of the parent molecule. Chromosomally <i>lux</i>-marked, non-toxigenic <i>E. coli</i> O157:H7 was selected as a model human pathogenic bacterium to demonstrate the disinfection potential of the batch reactor. Results of disinfection experiments indicated that a substantial decline in the population density of culturable <i>E. coli </i> O157:H7 cells was achieved. Accurate differentiation between the effects of photoelectrocatalysis and photolysis on the cells of <i>E. coli</i> O157:H7 was not achieved. The observed rate of the degradation of the model chemical compounds and the disinfection of the model human pathogen, demonstrated that visible light-driven photoelectrocatalysis offers considerable potential for remediation of contaminated water. Furthermore, toxicological biosensing can bridge the gap between traditional chemical analysis and ecologically relevant sample evaluation and address suitability of reintroduction of treated solution back into mainstream wastewater treatment.