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We may take our access to clean water for granted but recent events in Sweden and Europe have shown that a loss of water supply due to contamination does occur and can have large negative effects on society both financially and health wise. These events may become more frequent as the climate changes. This study investigates different aspects of crisis management for drinking water supply in municipalities in Sweden. The data was collected in a questionnaire sent out to the municipalities as a web-survey. The questionnaire included questions about the municipality’s ability to handle a failure in the main water supply and if a crisis in the drinking water supply was included in their risk and vulnerability analysis (RSA). The overall response rate was 15 %. The majority of the municipalities answered that drinking water supply was included in their RSA. Most of the municipalities lacked the ability to connect to a reserve water source, and the majority of those who were able, could not do so within 24 hours. A municipality’s ability to connect to a reserve water source did not vary with population between small (<20 000) and semi large (>20 000<100 000). The study indicates that there are improvments regarding crisis preparedness in the RSA and the ability to connect to a reserve water source compared to older studies however it also indicates that some municipalities are still not well prepared in case their primary water source of drinking water can not be used.

The natural occurrences of high (&gt;10 μg/L) dissolved arsenic (As) in groundwater of Bengal Basin has put millions of people under the threat of chronic As exposure through drinking water. Present study has examined the processes that regulate As mobilization and its distribution in shallow aquifers and the potentiality of finding safe aquifers within shallow depth (&lt;50 m) for drinking water supply. The results indicate that in terms of aquifer sediment colors and water quality two types of aquifer namely brown sand aquifer (BSA) and grey sand aquifer (GSA) can be distinguished within the depth, accessible by low-cost drilling. The redox condition in the BSA is delineated to be Mn oxyhydroxides reducing, not sufficiently lowered for As mobilization resulting in high Mn and low Fe and As in groundwater. While in GSA, currently the reductive dissolution of Fe oxyhydroxides is the prevailing redox process causing As mobilization into groundwater of this aquifer type. It is revealed that the vertical distribution of As and other aqueous redox parameters is related to the redox zonation within aquifer. The decoupling of As and Fe release into groundwater is evident in the shallowest part of aquifer because of Fe enrichment by weathering of silicate minerals especially of biotite, the precipitation of secondary mineral phases like siderite and vivianite and incomplete reduction of Fe oxyhydroxides. It is characterized that the seasonal variations of As and other aqueous solutes are limited within the upper portion of aquifer only (&lt;30 m bgl) and can be related to seasonal cycling of redox status, aggregation and dispersion of As scavenging colloids, local groundwater abstraction and monsoonal recharge. The results of surface complexation modeling indicate that PO43- is the major competitor of As(III) and As(V) adsorption onto Fe oxyhydroxides. This study concludes that the reductive dissolution of Fe oxyhydroxides followed by competitive sorption reactions with the aquifer sediment is the process conducive for As enrichment in groundwater of Bengal Basin. Present study advocates that despite low concentration of As in groundwater, a rigorous assessment of attendant health risk for Mn is necessary prior to considering mass scale exploitation of the BSA for sustainable drinking water supply. This study also validates that TW platform colors can be used as a rapid screening tool for As and Mn in drinking water wells to prioritize As mitigation management. / <p>QC 20130919</p> / EURINDIA 2009-1665

This thesis aims to address factors affecting the sustainability of development projects focusing on water supply in Ethiopia. The thesis identifies main dimensions of sustainability and examines factors within them and their impact on long-term functionality of the studied interventions. The research focuses on the (un)sustainability of the selected water supply projects in Sidama and Alaba, Ethiopia. Ten water supply systems constructed under three projects supported from the Czech development cooperation were examined. Data were collected through semi-structured interviews and direct observations of analyzed water systems. The interviews were conducted with experts, representatives of the implementing organization, representatives of water institutions in Ethiopia (Woreda Water Offices and WASH Committees) and recipients of the interventions, i.e. users of the water supply systems. This was supplemented by the analysis of project documentation. Field research in Ethiopia was conducted in November 2020 and lasted four weeks. The results showed ongoing long-term functionality with only minor problems in the majority of studied systems. One system was nonfunctional at the time of visit and two systems were facing serious problems. The sustainability of studied systems was affected mainly by...

La ville de Bangui, capitale de la République Centrafricaine, est sujette à de grandes difficultés en termes d'alimentation en eau potable. Un moyen de diversifier les ressources est de mettre en exploitation de façon plus importante les eaux souterraines à proximité de la zone urbaine. Deux aquifères existent sur le territoire, un aquifère superficiel dans les niveaux latéritiques et un aquifère en profondeur dans les niveaux carbonatés du Précambrien. L'aquifère superficiel, bien que très exploité, est un réservoir vulnérable et fortement marqué par les sources de pollutions anthropiques. Les caractéristiques isotopiques des eaux indiquent une très forte dépendance aux conditions hydrologiques de recharge et un rôle massif des processus d'évaporation sur la signature des eaux. L'aquifère profond est, quant à lui, dans des conditions semi-confinées et assez bien isolé des influences anthropiques. Les caractéristiques isotopiques des eaux sont en faveur d'une recharge plus homogène, au sein d'un réservoir de taille importante et sur une superficie notable autour de la zone urbaine de Bangui. Les temps de séjour calculés à l'aide du radiocarbone sur les eaux souterraines les plus profondes indiquent des "âges" de l'ordre de plusieurs siècles à environ 3000 ans, traduisant une forte inertie du système aquifère et par là même sont potentiel favorable à une exploitation pérenne et qualitative pour fins de production d'eau potable. / Bangui, capital of the Central African Republic, is subject to great difficulties in terms of drinking water supply. One way to diversify resources is to operate more importantly groundwater near the urban area. Two aquifers exist in the area, a surface water in lateritic levels and a deep aquifer in carbonate levels of the Precambrian. The surface aquifer, although very exploited, is a vulnerable reservoir and is also strongly influenced by anthropogenic sources of pollution. Isotopic characteristics of the water indicate a very strong dependence on hydrological recharge conditions and a massive part of the evaporation of water on the isotopic signature. The deep aquifer is, meanwhile, in a semi-confined situation and relatively well isolated from anthropogenic influences. Isotopic characteristics of the water are in favour of more homogeneous recharge processes, in a large reservoir and over a substantial area around the urban zone of Bangui. The residence times calculated using radiocarbon on the deeper groundwater indicate "ages" of the order of several centuries to about 3000 years, reflecting a strong inertia of the aquifer system and thus favourable exploitation conditions for the development of a sustainable and qualitative drinking water supply from groundwater.

The aim of the thesis is Kateřinice water treatment plant technical condition assessment and ascertained malfunctions elimination project. The documentation is enclosed. Essential part of the thesis is concerned with calculations and variant solutions of the object reconstruction and water treatment technology. Technical drawings of the water treatment plant are included. All the data was processed in accordance with valid laws and standards. The water treatment plant will be restored to its functional state on the grounds of the designed solution.Therefore permanent high quality of drinking water will be guaranteed for the inhabitants of Kateřinice.

Cyanobacteria are a unique organism, a bacterium that develop photosynthesis, thus it contains chlorophyll, a pigment commonly associated to algae. For this reason, cyanobacteria are also known as blue-green algae. One of the secondary metabolites of cyanobacteria is cyanotoxin, a substance which is hepatoxic, neurotoxic, and dermatoxic. The frequency and intensity of cyanobacterial blooms have been of increasing concern in the last decades for drinking water supply. There is a need to improve monitoring of cyanobacteria content at source water for drinking water supply and its indicators and correlation with other chemical, physical and biological parameters. This study aims to identify the potential cyanobacterial bloom risk in Lake Mälaren by determining the influential chemical and physical parameters using Random Forest in classification mode. The classification was done using the WHO Alert Level Frameworks and study cases for lakes in Sweden. The data used to model was downloaded from the website of the Swedish University of Agricultural Science. It comprises 33 monitoring stations from 1964 to 2020, 21 chemical parameters, including cyanobacteria biovolume and chlorophyll content. Given the heterogeneity of data, the monitoring stations were grouped into Clusters. Using the data, statistical, correlation, time series, and principal component analysis were performed. Through these methods, spatial, distribution and temporal analysis were obtained. Afterwards, several models were determined using Random Forest. However, the mean values of cyanobacteria distributed over time indicated a medium risk, the maximum values suggested high risk in several areas of the Lake. Maximum concentrations were present at the west and northeast of the Lake, where the major inflows from the Watershed are discharged. As the water flows through the basin, the concentration of cyanobacteria reduces by half, which suggested that the large and deep bays act as sedimentation ponds. A very high correlation was found between the Cluster 5 and 6, east and middle northeast of the Lake, respectively. Finally, the contributing factors identified after modelling cyanobacteria as target factor were chlorophyll, month, water temperature, oxygen content, transparency, NO2NO3N, TN/TP, Ca, Mg and Cl. / Cyanobakterier är unika organismer, bakterier som utvecklar fotosyntes, så de innehåller klorofyll, ett pigment som vanligtvis förknippas med alger. Av denna anledning är cyanobakterier också kända som blågröna alger. En av de sekundära metaboliterna av cyanobakterier är cyanotoxin, ett ämne som är hepatoxiskt, neurotoxiskt och dermatoxiskt. Frekvensen och intensiteten av cyanobakterieblomningar har varit ett ökande problem under de senaste decennierna för dricksvattenförsörjningen. Många vattenreningsverk mäter inte innehållet av cyanobakterier i vatten; medan andra kemiska, fysikaliska och biologiska parametrar mäts. Denna studie syftar till att identifiera den potentiella risken för cyanobakteriell blomning i Mälaren genom att bestämma de mest inflytelserika kemiska och fysikaliska parametrarna med hjälp av metoden Random Forest i klassificeringsläge. Klassificeringen gjordes med hjälp av WHO Alert Level Frameworks och olika studier av sjöar i Sverige. Data som användes för att modellera laddades ner från Sveriges Lantbruksuniversitets webbplats. Den omfattar 33 övervakningsstationer från 1964 till 2020, med 21 kemiska parametrar, inklusive cyanobakteriers biovolym och klorofyllhalt. Med tanke på heterogeniteten i data grupperades övervakningsstationerna i kluster. Med hjälp av data utfördes statistisk analys, korrelation, tidsserier och huvudkomponentanalys. Genom dessa metoder erhölls rumslig, distribution och tidsanalys. Efteråt bestämdes flera modeller med hjälp av Random Forest. Medelvärdena för cyanobakterier fördelade över tiden indikerade en medelrisk, medan maximivärdena antydde något annat. Maximala koncentrationer fanns i väster och nordost om Mälaren, där de stora inflödena från vattendelaren släpps ut. När vattnet rinner genom bassängen minskar koncentrationen av cyanobakterier till hälften, vilket tyder på att de stora och djupa vikarna fungerar som sedimentationsdammar. En mycket hög korrelation hittades mellan kluster 5 och 6, öster respektive mellan nordost om sjön. Slutligen var de viktigaste faktorerna som identifierades efter modellering av cyanobakterier som målfaktor klorofyll, månad, vattentemperatur, syrehalt, transparens, NO2NO3N, TN/TP, Ca, Mg och Cl.

Shortage of drinking water in most parts of the world has been a growing concern in recent times. The situation has been getting worse in underdeveloped and developing countries due to sudden explosion in population growth and the growth in the industries. The natural resources for potable water are limited and unless a feasible solution is obtained in the near future, the ‘concern situation’ may turn into a ‘panic situation’. A possible solution for the shortage in drinking water is to use water from inexhaustible sources such as oceans and seas and make it potable using desalination process. However, the process of desalination is an energy intensive process which the poor countries can not afford. In recent times, the cost of fossil fuels has been skyrocketing. With the crude oil costing more than Rs.5200 (US$120) a barrel as on September 2008, even the rich countries like USA and the countries in the European Union are feeling the pinch of the energy cost. Alternate energy sources such as solar, wind, geo-thermal, hydrogen etc., have become the order of the day. These sources are renewable and are environmental friendly. More than one third of the populations of the world live in coastal areas. These areas get abundant amount of solar energy throughout the year. Utilization of this energy in desalination process would solve drinking water problem to a very great extent. However, construction of centralized desalination plants requires large amount of capital which the poor countries can ill-afford. An alternate solution would be to construct decentralized smaller plants that would require smaller capital to construct and easier to maintain. If the energy requirement is tapped from renewable sources such as solar, then the operational cost also becomes affordable for the poor countries. By taking care of the water requirement of the coastal areas through this process, one may save large amounts of money in transporting potable water from interior areas to the coastal areas. There would be enough water for the people living in the interior areas. The water bed level in the interior areas would gradually increase, thereby reducing the drinking water concerns significantly. In this thesis, a small scale stand alone power generation system for the desalination process is proposed that is suitable to provide clean potable water from sources such as sea water or brackish water. Solar energy is proposed as a source of energy for the proposed desalination system. This source is available in plenty in arid and semi-arid areas. It is free and is also friendlier to the environment. It is proposed to use solar energy in thermal form to obtain energy equivalent of ‘latent heat of vaporization’ for the vaporization process and in electrical form for operating the dc machines and electronic control units that are integral parts of the desalination system. The proposed desalination unit can be built as small as possible even to feed a single household’s requirement and hence can be conceptualized as decentralized units. These units would require considerably less capital to build, and would require minimum maintenance. The desalination process is based on flash evaporation wherein a heated liquid is subjected to a pressure reduction by passing through a throttling device resulting in an initially superheated state. In the proposed desalination process, the traditional flash evaporator is extended to include continuous dynamic pressure modulation to obtain an optimal flow rate for a specified energy input. The cost function or the performance index for optimization is defined as the ratio of flow rate to the energy spent. The optimal flow rate occurs at a specific chamber pressure for a given inlet water temperature. By operating at optimal pressure, significant energy is saved for a specific flow rate. This principle is validated experimentally and the results are presented and discussed in the thesis. This proposed scheme along with hybrid energy input will prove to be an attractive solution for community drinking water problem. A system needs to have a mathematical representation in order to predict the dynamic behavior of the system. This thesis proposes the bond graph method of modeling the physical system wherein the energy flow across the electrical, thermal and the hydraulic domains are included. A system may comprise of several subsystems and the energy flow in each subsystem may be in a different domain. A desalination system is such a system wherein the energy flow in subsystems is in different domains such as electrical, thermal and hydraulics. The bond graph approach is best suited for modeling of such systems where the power/energy flow across domains can be easily and seamlessly integrated. The thesis proposes a fifth order dynamic model of a single stage flash evaporation with pressure modulation using the bond graph approach. The proposed model incorporates the effects of chamber pressure variation, the entropy flow from the chamber due to conduction, convection, radiation and also the thermal dynamics of the water bodies in the evaporation, condensation and collection chambers. The proposed model is simulated in MATLAB/Simulink environment. The simulation results are compared with the experimental results to validate the model. This proposed model can be used for both analysis and synthesis of a desalination system. The desalination system is a complex system wherein multiple energy domains are involved. The thesis presents a systematic process for the design of the desalination system. Design of the desalination system involves design of multi domain subsystems. The design becomes much more complex if the energy source to run the system is solar/ hybrid solar based. The energy budget has to be carefully evaluated considering the worst case conditions for the availability of solar energy. Hence, the information on the quantum of solar energy available at any location is a critical parameter needed for design of the desalination system. A generic method of developing a solar insolation model for a specific region such as the Indian sub-continent is proposed in this thesis along with the validation of the model by comparing measured value with the values that are obtained from the model. As the insolation model is dependent on the water vapor content in the vertical column at the location, the methodology is further applied to develop a model for estimating the precipitated water vapor content in a vertical column for any location. The model is validated by comparing the computed values to the measured values. The thesis further presents the design and selection of the balance of the system. The selection of the balance of the system includes sizing of solar thermal plate collectors such as flat plate for pre-heating and paraboloid for vaporization, solar PV panels for operating pumps, actuator and control units, and battery for backup source for night loads and during ‘no-sun days’, criteria of selecting centrifugal pump for circulating condensation water, vacuum pump for dynamic pressure modulation and selecting linear actuator for Sun tracking of the paraboloid concentrator. A discussion on the electronic circuits used in the control scheme is presented in this thesis. This includes the circuit for maximum power point tracking, circuit for DC-DC conversion, circuit for pressure modulation, circuit for speed control of linear actuator, and finally the circuit for water level limiter. A discussion on the life cycle costing is also presented in this thesis. This is an important parameter that refers to the accumulated worth of all the costs related to building and operating the desalination plant during its life span. It is emphasized that the objective of the design process is to minimize the life cycle cost while meeting other performance requirements. Thus, life cycle costing is an essential part of the design cycle. The design methodology and the approach used to design the desalination system are implemented in the form of a toolbox in the MATLAB environment. The various functions of the toolbox are highlighted by a detailed step by step presentation of the design modules in the thesis. The modules form the components of the design toolbox for designing the proposed desalination system.

Although the International Drinking Water Supply and Sanitation Decade has generated great interest from foreign aid donors, its impact. in terms of increased service levels has been poor. These disappointing results have been explained by the UN and other donors in terms of inadequate funding and lack of cost recovery, poor operations and maintenance, lack of personnel, unacceptable technology, poor logistics and non involvement of the beneficiaries. However, an alternative explanation revolves around factors contributing to poor project design. These include the lack of understanding of the development process, donor bias and self interest, and poor coordination and commitment by the recipient government. A review of the development and trends of contemporary aid philosophy and its translation in to rural development and water and sanitation projects, which led to the launch of the IDWSSD, provides a number of lessons that can be used to formulate a hybrid model for project design and the sector development process, that defines the relative roles of donors, recipient governments and people themselves. The model is based on coordinated development, community participation, and sector growth from pilot projects to large scale programmes. The developments in the rural water and sanitation sector that took place in Zimbabwe from 1974 to 1987, provide a unique opportunity to test this model using a systems analysis approach. After gaining Independence in 1980, Zimbabwe's development assistance funding grew tenfold with the influx of foreign donors, and major commitments were made by the new Government to rural development and the goals of the IDWSSD. However, the large investments in water and sanitation which included the preparation of a national master plan with external technical assistance, had both positive and negative impacts on the continuing development of the sector, the start of which can be traced back, well before Independence, to small pilot projects sponsored by non government organizations that used appropriate technology developed by the Rhodesian Government. This development process and the changing approach to project design is illustrated by a series of case studies of projects supported by multilateral and bilateral donors, and non government organizations, that were milestones during this period. Finally the project and sector development model is modified based on the practical lessons from Zimbabwe and recommendations for future practice are made together with suggestions for areas of further research.

This diploma thesis describes study of interconnection of Letohrad and Lanškroun water distribution systems. The thesis contains an overview of legislative regulations and technical standards related to the construction, design and directional solution of water supply systems. Following that, there is the description of the current state of the affected water mains. Next part is the design of interconnection including hydraulic analysis in using Epanet 2.0 software. The study contains several variants of the solution. The economic assessment is included.