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1.
Financing investments in water supply and sanitation has been a perennial problem in all countries of Latin America and the Caribbean. The contribution to capital funding derived from the income of operating companies has been very small, a direct consequence of unrealistically low tariffs. The situation has worsened with the increasing need to provide sewage treatment to reduce the gross pollution of most water bodies in the vicinity of large cities. This paper, on the basis of recent studies conducted in EC LAC, explores the practicability of the self-financing of water supply and sanitation services, including sewage treatment, through the income derived from tariffs. If this is to be achieved then it is important that the entire population pays for services, an issue of some importance given the unequal distribution of income in most cities of the region. The conclusion reached is that on the basis of the available information on costs, together with the experience of some countries, financing through tariffs is feasible, particularly if subsidies are provided to the poorest households. Tariff based financing is probably the only means of achieving universal coverage by the year 2000 as well as sewage treatment, the rehabilitation of existing systems, maintenance and the necessary institutional development .  相似文献   

2.
This paper describes the use of systems analysis and operations research techniques for the planning, design, and operation of specific parts of a water supply system. Only two areas of interest are emphasized and results of current research studies are indicated. The first topic deals with the optimal design and development of ground water sources, particularly the operation of well fields. The second topic deals with regional development of future supply sources. The question of which supplies should be developed, at what time, to what degree, and which transmission lines should be built to minimize the costs of regional water supply, are formulated mathematically. KEY WORDS: ground water; optimal design; systems; water supply  相似文献   

3.
Many countries in sub‐Saharan Africa have adopted similar approaches to tackle the challenges of rural water supply, including community‐based management, community participation and the demand‐responsive approach. These are often combined with nationwide programmes of capacity‐building and decentralization. This paper first shows how Uganda has adopted these approaches in its rural water supply programme. Based on Government documents, we construct an organizational framework that illustrates the overall programme and outlines the roles and responsibilities which actors are expected to fulfil. Second, based on interviews with sector staff and a review of Government documents, the paper examines challenges to successfully “walk the talk”; that is, it provides insight into challenges affecting programme implementation. Among numerous difficulties, two key issues are highlighted: local political interference and the weak capacity of local governments. Concerning local political interference, local planning processes need to be reformed so that local politicians commit more strongly to improving water supply. Regarding local government capacity, the Government department responsible for the programme has established eight regional units that provide support to local governments. This promising strategy, combined with more appropriate engagement and the commitment of local politicians, should help to improve the implementation of the rural water supply programme in Uganda.  相似文献   

4.
Wastewater irrigation is an environmentally sound wastewater disposal practice, but sewage is more saline than the supplied fresh water and the salts are recycled together with the water. Salts have negative environmental effects on crops, soils, and groundwater. There are no inexpensive ways to remove the salts once they enter sewage, and the prevention of sewage salt enrichment is the most immediately available solution. The body of initiatives presently structured by the Ministry of the Environment of Israel are herein described, with the aim to contribute to the search for a long-term solution of salinity problems in arid countries. The new initiatives are based on: (1) search for new technologies to reduce salt consumption and discharge into sewage; (2) different technologies to cope with different situations; (3) raising the awareness of the public and industry on the environmental implications of salinity pollution; and (4) an elastic legal approach expressed through new state-of-the-art regulations. The main contributor to the salinity of sewage in Israel is the watersoftening process followed by the meat koshering process. Some of the adopted technical solutions are: the discharge of the brine into the sea, the substitution of sodium by potassium salts in the ion-exchangers, the construction of centralized systems for the supply of soft water in industrial areas, the precipitation of Ca and Mg in the effluents from ion-exchangers and recycling of the NaCI solution, a reduction of the discharge of salts by the meat koshering process, and new membrane technology for salt recovery.  相似文献   

5.
Summary In the past, the water supply and sewage services for the urban regions of developing countries have been provided, in the main, only for the more affluent areas of these cities. This paper, dealing especially with those countries with tropical monsoon climates, advocates the construction of more comprehensive systems.Experience drawn from a wide range of projects and a review of the relevant literature provokes the authors to emphasise the need for suitable manuals of appropriate technology for use in these developing countries. These manuals should provide a full set of environmental guidelines for the design of water supply and sewage/sanitation systems for use in these countries.Dr Harvey F. Ludwig is Chairman and Greg Browder is Environmental Engineer for SEATEC International Consulting Engineers, Bangkok, Thailand.  相似文献   

6.
District heating (DH) is an important part of the Swedish energy system and one of the most important climate measures at the municipal level. The Swedish planning system gives a large amount of power to municipalities, thus leaving the regional level weak. Despite this, the DH systems in Stockholm have developed into regional systems; how has this development occurred and what made it possible? Regional and municipal strategies concerning DH and energy from 1978 to 2010 have been studied through Regional plans and comprehensive plans. The conclusions show that the municipal DH systems have grown and become interconnected, thus fulfilling one of the most important regional strategies: to expand and interconnect the systems to be able to build combined heat and power plants. This is not entirely due to the regional strategies, however; the local importance of the system, economic reasons and supply security are other explanations. The study shows that regional importance generally has grown, and thus also the regional focus on DH. As environmental and climate issues have risen on the agenda, the importance of DH from the municipal perspective has become more evident, as well as a shift from supply orientation to more focus on energy efficiency.  相似文献   

7.
This paper assesses the financing challenges which have to be met by developing countries if water resources are to be managed efficiently, if the quality of the aquatic environment is to be improved and if water related services are to be delivered in a responsive, efficient and equitable way. This paper takes the view that attaching 'price tags' to water supply and sanitation, as was tentatively done in Agenda 21, is a misguided approach and that what is needed is articulation of clear principles which should underpin the financing of water supply and sanitation investments. To illustrate the approach the paper focuses heavily on experiences from World Bank water supply, sanitation and urban development projects over the past 30 years. The challenge is to develop appropriate institutional and financial arrangements. The essence of such arrangements is that they ensure that societies mobilize appropriate levels of resources for providing water related environmental services and that these resources are used in the most efficient and effective way possible .  相似文献   

8.
ABSTRACT: It is estimated that by about 1984 water demand in the District will nearly equal Nature's average annual replenishment of the supply and that, thereafter, unless means are developed to augment our in-District resources, water mining will be required on a grand scale. Sources of augmentation include: (1) reduction of wastes; (2) industrial recycling of previously-used water; (3) use of municipal sewage effluents; (4) desalination of brackish ground water; (5) aquifer recharge from all available, high-quality sources, particularly flood waters; and (6) importation of excess waters from such out-of-District sources as the lower courses of the Suwannee and Apalachicola Rivers. To achieve maximum beneficial uses of in-District sources a regional water and sewer authority is needed that can develop and transmit water from all available sources to the various county and city systems on a wholesale basis. It is envisioned that such a supply system would tie together all production sources, much as the electrical generation and supply systems are currently organized into regional electric power hookups. At least two bills are currently before the Florida Legislature to achieve these goals.  相似文献   

9.
ABSTRACT: Proper economic evaluation of alternative plans will maximize the utility achieved from the resources available for water resource management. A knowledge of the frequency of occurrence of the events under study is necessary to fully utilize the advantages of economic evaluation in planning. Frequency information is widely used in flood control and water supply, but relatively unknown in water quality planning. A continuous, dynamic hydrologic and water quality model is presented to develop frequency curves for various water quality criteria. Results from the Denver Regional Water Quality Management Study are discussed as an example of the use of frequency analysis for economic evaluation of water quality management.  相似文献   

10.
Industrial ecology (IE) promotes the development of industrial systems based on recycling of matter and cascading of energy through cooperation. In this paper, the local/regional industrial ecosystem approach is reflected in two examples from Finland. The local forest industry system is based on renewable resources, waste materials and energy utilisation between forestry companies, a saw-mill, a pulp mill, a paper mill and a forest industry power plant. Waste energy from electricity production is used for production of heat and process steam. Regional city energy supply systems in Finland are also to a large extent arranged around power plants that utilise waste energy. The potential of combining the forest industry system with the energy supply systems of cities is considered and the conditions for success in the Finnish case are discussed.  相似文献   

11.
Community water supply programmes are seen as instrumental in achieving the goal of ‘safe’ water for all. Women, a principal target group of these programmes, are to be benefited with greater convenience, enhanced socio‐cultural opportunities and better health for themselves and their families, provided through improved water facilities. Water supply programmes largely consist of three essential components, namely: technology, people and institutions. Although such programmes are intended to benefit women members of local communities, scant attention is paid to the impacts of the socio‐cultural context of the community on these programmes. This article explores the influence of social and cultural intricacies on the implementation of community water supply programmes, and assesses their effectiveness. The article offers important lessons for the design and implementation of this type of programme. It concludes that the local socio‐cultural context sets the stage for programme implementation, being a dynamic factor that determines actual access to water sources, more so than mere physical availability, which is often used as a criterion for programme performance. The article stresses the urgent need to integrate socio‐cultural factors as a fourth dimension in designing community water supply programmes, and suggests practical measures for enhancing the effectiveness of such programmes.  相似文献   

12.
文章分析了目前长庆油田站场生活污水处理工艺存在的问题,对生活污水处理工艺进行了改进,采用膜生物反应器工艺处理生活污水以得到优质的中水,从而回收利用。通过对实际工程进行水质监测,COD、氨氮、浊度的去除效果好于GB 18920-2002《城市污水再生利用城市杂用水水质》中冲厕、绿化等用水要求。通过中水回用,形成"给水→利用→处理→循环利用"的中水回用模式,既节约了新鲜水,又减少了污水排放,保护了油区生态环境。  相似文献   

13.
Environmental legislation is increasing the amounts of bought-in electricity required for sewage treatment, and generating larger volumes of sewage sludge to be treated and disposed of. Concurrently, concerns over global warming and food safety from sewage sludge recycling on agricultural land is augmenting the costs of conventional sewage and sludge treatment technologies and practices. This paper reviews some emerging technologies and practices that may assist in mitigating these problems in the future. In addition, a number of potential renewable energy technologies available to water companies are reviewed. Results suggest that through the take-up of new technologies, current and future water quality standards could be delivered in a more sustainable way. However, this series of papers also highlights that institutional and political conflicts may have inadvertently failed to recognise the wider effects of improving water quality and lessened the financial support necessary for their widespread take-up. It is also suggested that through the use of a Strategic Environmental Assessment (SEA) approach, stakeholders could gain a better understanding of the broader environmental effects of achieving certain water quality standards and develop policy and long-term investment strategies accordingly. However, to fulfill the information requirements of an SEA, an appropriate appraisal tool that considers many of these factors in unison is required, and a possible technique is suggested.  相似文献   

14.
The traditional approach to water resources management for urban areas has been based on the examination of needs and the design of separate facilities for water supply, drainage, and waste water collection and treatment. The complexity and interaction among the separate systems required by a metropolitan area has complicated their management and promoted research interest in developing a methodology for better coordination. However, a more thorough evaluation of the problem reveals the real research need to be both more complicated and different in character than the problem in systems analysis suggested by the first superficial glance. Water management relates to the much broader problem of community design; when, where, and in what manner should new urban development take place. Furthermore, the character and needs of areas within the metropolis are constantly changing. The key distinctiveness of urban water management is the imperative for design and operation flexibility. The key research need is to develop new designs, operation procedures, and institutional arrangements to make the flexibility demanded by a dynamic urban community possible.  相似文献   

15.
Non-sustainability of programmes and projects has become an overriding concern for the water supply and sanitation sector. Poor programme conceptualization, unimaginative planning, use of inappropriate technologies and rigid management approaches have contributed to high rates of programme failure. Five major water supply programmes undertaken during the UN Water Decade in the Western Sudan were analysed for their management approaches, appropriateness and sustainability. Results prompt the conclusion that sustainable projects need to adopt an adaptive and flexible management approach and to employ a conceptual framework which emphasizes community management, the empowerment of women, selection of appropriate low cost technologies, built in operation and maintenance strategies, cost recovery and institutional support to government.  相似文献   

16.
17.
Abstract: This paper describes an interactive data and model generator that is intended to bridge the gap between the water resource enginner and planner and the mathematical progrmming systems approach to regional water supply planning. The optimization objective is to minimize total annual cost with respect to capital investment and operation and maintenance costs. The matrix generator formulates the necessary hydrologic, demographic and programming problem for system optimization. The interactive program guides the user through the input and optimization segments, totally eliminates the chore of manually structuring the model matrix aides in eliminating errors, and allows use by planners without skill in mathematical programming.  相似文献   

18.
ABSTRACT: A model consisting of closed water reuse and productive use of various types of wastes for energy generation is presented. The sewage after treatment would be used as the cooling water for power plants, and the condenser discharge therefrom be used as heating water for sludge digesters. The water is then purified for municipal water supply for continuous use. The advantages of this system are that water resources and energy are conserved while various types of wastes including waste heat are controlled. With a preliminary system analysis, it appears that the design for power plant based on the total heating value of wastes and digester capacity based on sewage sludge generation is feasible in terms of acquisition and full utilization of various types of wastes as generated in a single metropolitan area. The system as shown in this design is in balance among various factors such as the generation rate of municipal refuse, municipal sewage, waste heat in the condenser discharge, and raw sewage sludge.  相似文献   

19.
The United Nations ground water exploration and development programme during 15 years of active life, has resulted in substantial socio-economic benefits to 57 developing countries through some 100 ground water projects. Systematic study, development and use of this important resource have contributed to intensification of agricultural production through supplemental irrigation from ground water; alleviation of water shortages in urban and industrial areas through construction of supply wells; improvement and stabilization of pastoral and rural economies, thereby counteracting in some measure adverse demographic trends of migration to the cities; and other related benefits in training, institutional development, and development of national water policies and plans.  相似文献   

20.
An 11-year period of water quality data, collected by the Directorate of Sate Water Works of Turkey are thoroughly analyzed for the purpose of implementing water quality classes to water resources in the Meric Basin, located on the European land mass of Turkey. Water quality parameters are divided into four groups as physical, organic, inorganic, and bacteriological. The quality class of each group is evaluated by taking into account the poorest quality of any parameter in the group, after which a quality rank is assigned to the sampling station and the waterbody in question. This method of water quality classification imposed by the Turkish Water Quality Act, is then criticized with respect to a statistical approach.  相似文献   

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