Showing papers on "Water supply published in 1982"

Water Distribution Systems: A Spatial and Cost Evaluation

Abstract: Problems associated with maintaining and replacing water supply distribution systems are reviewed. Some of these problems are associated with public health, economic and spatial development of the community, and costs of repair and replacement of system components. A repair frequency analysis has been completed for distribution system maintenance events (leaks and breaks). The economic implication of various replacement strategies and the effect of water quality (corrosivity) on water loss and system cost are examined. This analysis is based on the data acquired from tne large (260 mgd; 11.39 m³/s) and one smaller (20 mgd; 0.88 m³/s) water utility. As this study shows, once a length of pipe begins to require maintenance, its maintenance rate increases exponentially. Maintenance costs soon exceed the costs of replacement. Therefore establishing a timely maintenance and replacement program is extremely important from an economic and public health viewpoint.

Consequences and responsibilities in drought forecasting: The case of Yakima, 1977

Abstract: This study is concerned with the impact of an actual forecast of total water supply available (TWSA) made by the Bureau of Reclamation for irrigators in the Yakima Valley (Washington). Estimates of TWSA (legally calculated by combining natural flow estimates, water storage, and other sources, i.e., return flow) were issued in February 1977, suggesting that less than half of the long-term average water supply would be available for the coming irrigation season. The Bureau allocated the estimated TWSA as follows: those with nonproratable (senior) water rights were to get 98% of their normal water allocation, while those with proratable (junior) rights were to receive about 6%. The TWSA estimate and subsequent water allocations prompted irrigation districts, as well as individual farmers and federal, state, and local government agencies, to take a variety of measures they might not otherwise have taken. By May 1977 the Bureau realized that there was more water in the system than they had expected and that some of their assumptions had in fact distorted their projections of TWSA. Many farmers took legal action against the Bureau to recover costs they claimed were incurred by their responses to the erroneous water supply projections. This study raises questions about societal responses to seasonal water supply estimates and about the benefits to society of good forecasts as well as the costs of erroneous ones. It also raises the issue of who, if anyone, should bear the responsibility for the societal implications of such forecasts.

Estimation of Substitution Possibilities between Water and Other Production Inputs

Abstract: The traditional approach to measuring the demand for water by industries relies upon fixed water-use coefficients. Water supply planners base decisions about system expansion partly upon fixed coefficients applied to projected levels of industrial growth. Among the restrictive assumptions implied by this approach is that producers are generally unresponsive to the relative price of water compared with other factors. Earlier studies focused on industry-by-industry assessments of present and potential water use technologies and the possibilities for substituting other productive inputs for water. Most of these studies are economic engineering in form. Thompson and Young and Russell are analyses of the steam electric-generating industry and the petroleum refining and petrochemical industry, respectively. Because they used linear programming techniques, their results must be interpreted cautiously. The flexible functional forms which have become

The Growth of the Utilities Industries in Italy, 1861–1913

Abstract: This article presents new estimates of the Italian utilities industries' production from 1861 to 1913. The improvements over the currently available series include the restriction of the electricity series to the production of the electric utilities, the extrapolation of the gas production series to 1861, and the calculation of production series for the water supply industry. These new estimates suggest that the existing aggregate production series significantly overstates the utilities' growth rate. The existing utilities series for other countries do not incorporate separate estimates for the water supply industry, and also appear to overstate the industryapos;s growth rate.

Appropriate sanitation alternatives : a technical and economic appraisal

Abstract: The United Nations has designated the 1980's as the International Drinking Water Supply and Sanitation Decade. Its goal is to provide two of the most fundamental human needs - safe water and sanitary disposal of human wastes - to all people. Since the technology for supplying water is better understood, the emphasis in this volume is on sanitation and waste reclamation technologies, their contributions to better health, and how they are affected by water service levels and the ability an willingness of communities to pay for the systems. This volume summarizes the technical, economic, environmental, health, and sociocultural findings of the World Bank's research program on appropriate sanitation alternatives and then discusses the aspects of program planning that are necessary to implement these findings. It is directed primarily toward planning officials and sector policy advisers for developing countries. The most important finding is that there are many different kinds of technology that can be safely and cheaply used on a wide scale. Sanitation sequences - step-by-step improvements in sanitation techmology that can build on eahc other as a community can afford to upgrade its system - are also designed and costed. In addition, a new and promising approach is presented to the problem of linking potential benefits to health with improvements in environmental sanitation.

Cost Estimating for Conventional Water Treatment

Abstract: The Safe Drinking Water Act of 1974 emphasizes the need to take costs into consideration when promulgating regulations This paper presents cost equations that can be used for water treatment unit process cost estimating The need for pre-design estimates is discussed, and the factors affecting the reliability of cost estimates is examined These factors include availability of basic data, stage of development, definition of scope, the time expended on analysis, and experience of the analyst Data for these equations were derived from a carefully designed study to establish water supply unit process costs on a consistent and understandable basis The basis for derivation of these curves is presented Examples of the application of these equations are developed based on a standard layout for a water supply treatment plant and assumed standard values for the input factors for the cost equations

Water from power: water supply and regional growth in the santa clara valley*

Abstract: The principal task is to uncover the origins of water development in a major urban area. The major thesis examined is that the demand for water arising from agricultural and urban growth is the dom...

Reliability, Resiliency, Robustness, and Vulnerability Criteria for Water Resource Systems

Abstract: Three criteria for evaluating the possible performance of water resource systems are discussed. These measures describe how likely a system is to fail (reliability), how quickly it recovers from failure (resiliency), and how severe the consequences of failure may be (vulnerability). These criteria can be used to assist in the evaluation and selection of alternative design and operating policies for a wide variety of water resource projects. The performance of a water supply reservoir with a variety of operating policies illustrates their use. When water resource investments are made there is little assurance that the predicted performance will coincide with the actual performance. Robustness is proposed as a measure of the likelihood that the actual cost of a proposed project will not exceed some fraction of the minimum possible cost of a system designed for the actual conditions that occur in the future. The robustness criterion is illustrated by its application to the planning of water supply systems in southwestern Sweden.

Water for western agriculture

Abstract: The continued increase in American farm productivity depends to a large extent upon the availability and cost of water resources. The report in this book is one of three prepared by Resources for the Future on irrigation. It examines the role of western irrigation and the impacts of the changing water supply situation on the development of western irrigation. Past trends, water-supply conditions, water institutions, economic forces, technological alternatives, and environmental factors are examined for their impact on the course of western irrigation over the next two or three decades. The influence of these institutional and economic forces on resource use and the environment are also considered along with the broad policy implications of the analysis. The report concludes that the West is only running out of low-cost water, and no set of policies and programs will alter the fact that water is becoming increasingly valuable. Reviewing existing laws that helped to foster western development and raising the market value of irrigation are among the suggested approaches. 203 references, 3 figures, 49 tables.

The sanitary condition of rural drinking water in a Nile Delta village II. Bacterial contamination of drinking water in a Nile Delta village

Abstract: Whilst the major danger associated with drinking water is that it may be contaminated with sewage or human excreta, the danger of pollution from animals must not be overlooked. Outbreaks of infection from drinking water are frequently reported (Melnick & Gerba, 1979) and high prevalence rates of diarrhoeal diseases have been found in the Nile Delta (Sallam et al. unpublished data). The supply of potable water is a critically urgent national problem and is of especial importance to communities which must rely on poorly designed supply systems and which lack even the minimum quality control services. The bacteriological control of potable water depends on counting certain micro-organisms as indicators of faecal pollution. Although pathogenic coliforms other than Escherichia coli are found in faecal material, their low frequency makes it difficult to use them as indicators of pollution (Papavasilliou, 1958; Dufour, Strickland & Cabelli, 1975); however counts of E. coli may be relied upon as indicators of pollution (Hufham, 1974). A study of the ratio of E. coli to faecal streptococci provides an indication of the source of pollution, a ratio less than 0.7 indicates an animal source, whilst a ratio over 4 indicates a human source (Geldreich & Kenner, 1969). Although the village studied is supplied with municipal treated water, over 90 % of the villagers still use water after storage in a 'Zir' since this provides cooled water (El Shafhy, unpublished data). The zir is an earthenware, conical-bottomed vessel through which water seeps and evaporates, cooling the remainder. This paper reports a bacteriological study of tap water and zir water in one village.

Analytical Bibliography for Water Supply and Conservation Techniques.

Abstract: : The information contained in this volume is designed to assist planners in the application of the planning methodology described in The Evaluation of Water Conservation for Municipal and Industrial Water Supply: Procedures Manual. The primary objectives of this volume are to update and revise the existing Annotated Bibliography on Water Conservation, making it a more useful reference for planners, and also to identify, describe, and discuss the underlying rationale, special problems, and useful sources of information for each of the required steps in the Procedures Manual. (Author)

Residential Water Conservation in a Noncrisis Setting: Results of a New Jersey Experiment

Abstract: East Brunswick Township, New Jersey, conducted a water conservation program in 1980 by distributing to 564 households free packets of water-saving devices purchased with municipal funds. The program was not a response to a current water supply crisis, and appeals for cooperation were based on the private economic benefits of water conservation. Statistical procedures were developed to measure the proportions of households installing each of the devices distributed, water savings and program costs. Two-thirds of the households receiving the packets installed at least one device. Average annual water savings per home receiving a packet were estimated at 5010 gallons (18.96 kl). Amortized over ten years at a 10% discount rate, the program cost was approximately 35 cents per 1000 gallons of water saved (9.2 cents per kl). The East Brunswick results compare well to the results obtained from similar conservation programs in a pair of California communities during the 1976–1977 drought.

Sizing Farm Reservoirs for Supplemental Irrigation of Corn. Part 11. Economic Analysis

Abstract: A procedure is presented for determining the optimum reservoir size, based on economics, for water supply for supplemental irrigation. The procedure can also be used to evaluate the risk involved in investing in sup-plemental irrigation. The Duncan-SIMAIZ model is used to calculate crop yields under irrigated and nonir-rigated conditions as well as daily irrigation water re-quirements. The Haan water yield model is used to calculate daily water yields into a water supply reservoir. These models are used along with a reservoir water balance and a present worth economics procedure to defme the economics of investing in supplemental irriga-tion as well as determining the optimum reservoir size. The procedures are described and example computations presented.

Rural water supply and health : the need for a new strategy

Abstract: In poor countries there is a linkage between lack of safe water, high levels of infections, and high rates of child mortality. To cope with this world-wide problem, the United Nations has launched ...

Conflict Between Establishment of Instream Flows and Other Water Uses on Western Streams

Abstract: Establishment of minimum stream flows on most streams in arid areas of the west will create serious water conflicts. Much economic activity is dependent upon a limited water supply. to attempt to reallocate water to maintain minimum flows will cause severe disruption to planned uses of water and to weak segments of the economy such as irrigated agriculture.

Urban Water Conservation : Increasing Efficiency-in-Use Residential Water Demand

Abstract: Water supply and wastewater flow problems have resulted in an increasing concern with urban water demand. This report is an assessment of various water conservation measures aimed at reducing residential water usage. Demand reduction alternatives are examined and those applicable to residential areas are identified. Structural means such as water meters, recycle systems, water saving devices and flow reduction devices are examined. System and household leakage reduction as well as water use restrictions are among the operational methods investigated. Social and economic methods of public education, building code modifications, horticultural changes, and pricing policy are also studied. The literature is reviewed to determine the water savings that each conservation method can accomplish. The amount of water savings and the return flow implications for each method are investigated. Estimates of the combined impact of several methods used together in a common program are postulated. An assessment, based on this available data, found that water demand reductions of as much as 35 to 40% are possible through implementation of a combination of water conservation methods without incurring undue hardship on most water users. It is concluded that demand reduction techniques could successfully be incorporated in a water utility's management program.

Land use survey of the Upper Hunyani catchment

Abstract: This study examines the land use patterns within the Upper Hunyani River catchment, an area of 2136 km2. Its purpose is to facilitate the understanding of the ecological system of Lake McIlwaine at the lower limit of the study area. Lake McIlwaine, together with the other large dams on the Hunyani River, the Prince Edward and Henry Hallam Dams and Lake Robertson (Darwendale Dam), are the main sources of the water supply for both domestic and industrial use in the City of Salisbury, Zimbabwe.

Decision analysis for water resources planning

Abstract: Quantitative decision analysis techniques were applied to a particular problem of water resources planning: how should the water supply of the metropolitan Boston area be increased to meet the projected demand for 1990? The analytic approach used a multiattribute value model to evaluate several alternatives from the points of view of different interested constituencies. The model was presented to a number of individuals and groups with responsibility for recommending policy, and they indicated an interest in the findings.

Water and Wastewater Quality Control and the Public Health

Abstract: This paper describes the public health hazards associated with the use of water and the protection provided by engineering control of such hazards. It presents first the problems of drinking water supply, and then those of wastewater management. It discusses the engineering approaches to con­ trolling the microbial agents of water-borne diseases and the chemicals that have been actually or potentially implicated in producing human illness through the water route. It focuses on chemical contaminants of industrial origin; on trihalomethanes, which result from the reaction of chlorine and natural humic substances; and on inorganic compounds of special health interest. The future role of dual water supplies in communities is consid­ ered. The paper describes the sharply increasing concern with deteriorating quality of groundwater sources. The following major components of a wastewater management program are described in some detail: water qUality objectives, wastewater treatment, and water quality surveillance. The paper discusses the effects of disposing of wastewaters by application on land. It examines the problems of com­ bined sewer overfl ows and nonpoint pollution, the latter having emerged as a perhaps more frustrating and, from a public health point of view, more significant problem than the point source of pollution. Finally, the paper describes the important problem of wastewater residuals management, namely, control of sludges and industrial waste liquor concentrates.