Showing papers on "Water supply published in 1988"

The Environmental Impact

Abstract: Western scientists, using data from both Soviet and non-Soviet sources, have estimated the future cancer rates as a result of the disaster. They are on less secure ground when trying to assess the environmental impact of the accident. As the above quotation reveals, some Soviet citizens themselves remain uncertain about the consequences. The situation was complicated by the unevenness of the fallout and the contradictory statements issued by the authorities regarding the need for precautions. This chapter will also examine the question of the water supply in the Chernobyl area, but it should be stated at the outset that no figures on water contamination have been made available.

Scarcity Rents for Water: A Valuation and Pricing Model

Abstract: For most natural resources, the existence of scarcity and the extent of the scarcity rent can be readily determined, at least conceptually That portion of the resource price in excess of extraction costs signals scarcity and defines the value of the resource in situ Drawing on Hotelling's (1931) treatment, Heal (1976), Pindyck (1978), and Hanson (1980), among others, have used various forms of this relationship to analyze efficient extraction and consumption of natural resources Given clear ownership, no externalities, and the existence of viable markets, competitive market processes will establish the efficient level of this rent and, thus, the efficient time path of extraction and consumption In the absence of clear ownership rights and markets, however, scarcity value frequently goes unrecognized Water resources provide an important example of this phenomenon, given the growing apparent shortages in both urban and agricultural uses Government agencies typically "own" the resource or otherwise have free access to it and need only cover extraction, treatment, and distribution costs Ignoring scarcity rents in water pricing means that water prices are too low, thereby inducing excessive extraction, capacity investment, and consumption Even if water utilities were aware of the concept and importance of scarcity rent, the absence of marketdetermined water prices makes the valuation of scarcity rents very difficult Most water supply utilities obtain water from sources that have a recognized, finite capacity This occurs where the withdrawal rates exceed the current rate of recharge A similar situation exists when utilities approach their legal entitlement to some given water source, such as California water authorities now face with respect to their Colorado River rights The anticipated higher cost for water implies a scarcity rent (Howe 1979, 78ff) on use of existing cheaper water sources today The usual lack of markets in water makes this rent implicit, but it exists just as with oil or diamonds or any scarce natural resource This c st is completely distinct from outlays for exploration, development, transmission, treatment, and distribution which, as out-ofpocket costs, readily become embedded in conventional water prices Scarcity rent could arise with or without economies or diseconomies of scale in extraction or distribution It

A Neglected Water Resource: The Camanchaca of South America

Abstract: Many parts of the world are currently suffering water shortages. Few areas, however, have as little precipitation and groundwater available to alleviate the problem as does the northern coast of Chile. The historical background of the attempts to collect water directly from the coastal stratocumulus decks is reviewed in this paper as are the meteorological and geographical considerations important to the collection of the cloud water. Calculations of water availability and cost indicate that this may well be an important source of water for some coastal regions. A combined research and applied project to study the properties of high-elevation fogs and their use as a water supply will be conducted by Chilean and Canadian agencies from late 1987 to the end of 1988.

Coping with Crisis? The Diffusion of Waterworks in Late Nineteenth-Century German Towns

Abstract: The article examines the diffusion of waterworks in one hundred Rhenish Prussian towns. It exploits features of the institutions of local political representation to develop and estimate a median voter model of demand for water capacity. The results suggest that rising income of the median voter and demand of industrial users, rather than crises in public health, spurred the installation of improved water supply.

Epidemic giardiasis caused by a contaminated public water supply.

Abstract: In the period November 1, 1985 to January 31, 1986, 703 cases of giardiasis were reported in Pittsfield, Massachusetts (population 50,265). The community obtained its water from two main reservoirs (A and B) and an auxiliary reservoir (C). Potable water was chlorinated but not filtered. The incidence of illness peaked approximately two weeks after the city began obtaining a major portion of its water from reservoir C, which had not been used for three years. The attack rate of giardiasis for residents of areas supplied by reservoir C was 14.3/1000, compared with 7.0/1000 in areas that received no water from reservoir C. A case-control study showed that persons with giardiasis were more likely to be older and to have drunk more municipal water than household controls. A community telephone survey indicated that over 3,800 people could have had diarrhea that might have been caused by Giardia, and 95 per cent of households were either using alternate sources of drinking water or boiling municipal water. Environmental studies identified Giardia cysts in the water of reservoir C. Cysts were also detected in the two other reservoirs supplying the city, but at lower concentrations. This investigation highlights the risk of giardiasis associated with unfiltered surface water systems.

Groundwater Dams for Small-Scale Water Supply

Abstract: Looking at inexpensive methods for water supply schemes in rural areas of developing countries, this book examines the suitable conditions and economic factors for different types of groundwater dam and describes planning and investigation methods.

Bacteriological contamination of water in rural areas: an intervention study from Malawi.

Abstract: The bacteriological quality of drinking water sources and of stored household water was examined in a rural area of Malawi, before and after improvement of the method of water supply. Among the traditional water sources, water quality was better in springs than in wells and rivers. During the rainy season, there was a considerable deterioration of water quality, which was most pronounced in wells. The improved water supply system consisted of piped, untreated surface water from an uninhabited mountain area. This water contained a mean value of 54 faecal coliforms per 100 ml which can be regarded as acceptable in this setting. During collection of drinking water and during household storage, there was considerable contamination, which mirrored the unhygienic environment. Contamination was worse during the rainy season than during the dry season. Technical interventions aimed at improving water supply in rural areas of developing countries will probably not become effective unless combined with comprehensive health education programmes for the population concerned.

Watering white elephants?: Lessons from donor funded planning and implementation of rural water supplies in Tanzania

Abstract: The book presents five case studies on various donor approaches to the preparation of long-term regional water supply plans in Tanzania and their subsequent implementation (Denmark, Finland, Hollan ...

A case-control study of the effect of environmental sanitation on diarrhoea morbidity in Malawi.

Abstract: A case-control design has been applied in the evaluation of improved environmental sanitation on diarrhoeal diseases in rural Malawi. The study demonstrates the feasibility of using such an approach to evaluate two levels of water supply and sanitation service quickly and at moderate cost. Sample sizes would need to be increased substantially to evaluate multiple levels of service or to investigate interactions between water supply and sanitation. The results indicate that children living in families who use good quality water supplies and latrines experience 20% less diarrhoea as reported to the health clinics during the warm, rainy season.

Contaminant Propagation in Distribution Systems

Abstract: The Safe Drinking Water Act (SDWA) of 1974 requires that the U.S. Environmental Protection Agency (EPA) establish maximum contaminant levels (MCLs) for each contaminant which may have an adverse effect on the health of persons. The SDWA clearly specifies that these MCLs shall be met at the consumers tap. Nevertheless most regulatory concern has been focused on water as it leaves the treatment plant before entering the distribution system. There is, however, growing interest in determining the factors that cause water quality variations in drinking water distribution systems. In order to study this effect, the Drinking Water Research Division of EPA initiated a cooperative agreement with the North Penn Water Authority. This cooperative agreement has resulted in a series of field monitoring and systems modeling studies that lend insight into the movement of contaminants in distribution systems. Previous research has resulted in development of a steady-state model, a quasi-steady-state model and dynamic model that have provided useful approaches to modeling the general propagation of contaminants in distribution systems. In this paper, results from the steady-state model are utilized to examine the actual pathways of water flow and the time of passage and percentage of water that flows from a given source to a given node in a distribution system. The contaminant propagation technique developed from this extension of the steady-state model provides a useful technique for analyzing many of the factors that affect water quality in a distribution system. A major finding of this research study is the importance of adequate hydraulic modeling of the systems being studied and the importance of field studies in verifying systems performance. The approach suggested in this research will provide useful insight into the water quality variations that may impact consumers at the tap and the development of time and spatially sensitive monitoring strategies.

A model of daily municipal water use for short‐term forecasting

Abstract: A time series model of daily municipal water use is developed. The model is termed a conditional autoregressive process and can be interpreted as an autoregressive process with randomly varying mean. The randomly varying mean accounts for changes in water use that result from the complex interaction over time of “structural features” of the water use system. These features may include the price of water, total service area connections, plumbing code provisions, and customer income, among many others. The modeling approach is semiparametric. The model can be split into a component that is treated in a nonparametric framework and a component that is treated parametrically. The random mean process, which represents long-term trend in water use, is treated in a nonparametric framework. Conditional on the random mean water use, the model reduces to a Gaussian autoregressive process with a modest number of parameters. The water use model is the core of a forecast system which is used to schedule releases from two water supply reservoirs which serve the Washington, D.C., Metropolitan Area. Model structure dictates that the key step in producing a water use forecast is an updating step in which a revised estimate of current mean water use is computed.

Agriculture and water quality

Abstract: Agriculture generates byproducts that may contribute to the contamination of our Nation's water supply. Any effective regulations to ban or restrict agricultural chemical or land use practices in order to improve water quality will affect the farm economy. Some farmers will benefit; some will not. Most agricultural pollutants reach surface waterways in runoff; some leach through soil into ground water. Because surface water systems and ground water systems are interrelated, farm management practices need to focus on water quality in both systems. Modifying farm management practices may raise production costs in some areas. Farmers can reduce runoff losses by reducing input use, implementing soil conservation practices, and changing land use. Also at issue is who should pay for improving water quality: farmers, governments, consumers, or those who benefit from improved water quality.

Adjusting water resources management to climate change

Abstract: The nature of climate impacts and adjustment in water supply and flood management is discussed, and a case study of water manager response to climate fluctuation in California's Sacramento Basin is presented. The case illuminates the effect on climate impact and response of traditional management approaches, the dynamic qualities of maturing water systems, socially imposed constraints, and climate extremes. A dual pattern of crisisresponse and gradual adjustment emerges, and specific mechanisms for effecting adjustment of water management systems are identified. The case study, and broader trends in U.S. water development, suggest that oversized structural capacity, the traditional adjustment to climate variability in water resources, may prove less feasible in the future as projects become smaller and new facilities are delayed by economic and environmental concerns.

The effects of future climatic changes on international water resources: the Colorado River, the United States, and Mexico

Abstract: International water resources have been a source of contention in many parts of the world over the last few decades and such conflicts may grow in frequency and severity as future climatic changes alter the quantity or quality of limited water resources. Indeed, some future climatic changes appear inevitable due to growing atmospheric concentrations of carbon dioxide and other trace gases. Unless mechanisms for incorporating climatic changes into water agreements can be worked out, these changes may provoke further frictions and conflicts. One region with a history of political conflict over shared water resources is the Colorado River Basin in the United States and Mexico. While past disagreements over water have mostly been resolved, future climatic changes that adversely affect the existing hydrologic regime of the basin cannot be discounted. This paper examines the possibility that future long-term climatic changes may exacerbate shortages in the Colorado River. Political conflicts and tensions that arise from reductions in water supply in both the United States and Mexico are evaluated and discussed, together with recommendations for incorporating the issue of climatic change into existing international treaties and agreements.

On-board water supply

Abstract: Water supply in aircraft for on-board use in conjunction with water outlets in lavatories and a galley, includes a waste water tank connected to at least some of the waste discharge outlets on board of the aircraft; a water purifying plant connected to and receiving water from the waste water tank; and a fresh water tank having outlet means, connected at least to some of the water outlets, and having an inlet connected to said water purification plant, for receiving therefrom purified waste water; an additional tank for drinking water may be provided as well as a separate supply line therefrom leading to drinking water outlets on board of the aircraft.

Information, the decision forum, and third-party effects in water transfers

Abstract: Transfers of water from irrigation to municipal and industrial uses are seen as a low-cost approach to the water supply problems of western cities. Rural areas of origin protest that market transfers ignore indirect economic, political, social, fiscal, and environmental effects of changes in water use. The capacity of five different water transfer institutions: the market, courts, legislature, special purpose districts, and administrative agencies, to develop and weigh information about indirect and nonuser impacts is analyzed and compared. All five forums are found to have biases regarding the type of information used. Markets process information on direct economic costs and benefits well but ignore third-party costs; legislative bodies are sensitive to information about indirect and nonuser impacts but distort information on direct benefits and costs; neither the judiciary nor the water agency is likely to consider community and social impacts of water transfers. Special districts could consider both direct and indirect values but are often controlled by a leadership elite, pursuing narrow goals with minimum membership participation. The appropriate forum for decision making depends upon our priorities among values and on the values that are at stake in particular issues.

Irrigation Optimization Under Limited Water Supply

Abstract: Atwo-stage simulation/mathematical programming model was developed to determine the optimal intraseasonal allocation of irrigation water under conditions of limited water availability. The model was applied to a representative surface irrigated farm in Washington State's Columbia River Basin. Results from applying the model to a series of incifeasingly severe water shortage conditions indicated a large potential for water conservation in the assumed production setting. Farm-level water supply reductions of 40% translated to about 10% decrease in economic returns. Income losses resulting from water shortages were minimized through the conjunctive management of irrigation scheduling, irrigation labor practices, and several other short-run responses to water deficits. The combination of crop water simulation and farm-level economic optimization models was shown to be a compatible merger of techniques for representing the engineering and economic irrigation environment.

Volume sharing of reservoir water

Abstract: Previous models optimize short-, intermediate-, and long-run irrigation decision making in a simplified river valley system characterized by highly variable water supplies and demands for a single decision maker controlling both reservoir releases and farm water use. A major problem in relaxing the assumption of one decision maker is communicating the stochastic nature of supplies and demands between reservoir and farm managers. In this paper, an optimizing model is used to develop release rules for reservoir management when all users share equally in releases, and computer simulation is used to generate an historical time sequence of announced releases. These announced releases become a state variable in a farm management model which optimizes farm area-to-irrigate decisions through time. Such modeling envisages the use of growing area climatic data by the reservoir authority to gauge water demand and the transfer of water supply data from reservoir to farm managers via computer data files. Alternative model forms, including allocating water on a priority basis, are discussed briefly. Results show lower mean aggregate farm income and lower variance of aggregate farm income than in the single decision-maker case. This short-run economic efficiency loss coupled with likely long-run economic efficiency losses due to the attenuated nature of property rights indicates the need for quite different ways of integrating reservoir and farm management.

Assessing Preferences in Cost‐Benefit Analysis: Reflections on Rural Water Supply Evaluation in Haiti

Abstract: This article examines an area of cost-benefit methodology which has come under increasing philosophical scrutiny in recent years: the appropriate treatment of individuals' preferences. We illustrate some of the difficulties involved in assessing preferences in the context of a concrete example: the evaluation of a rural water supply project in southern Haiti. Four problems in the application of cost-benefit principles are discussed: (1) how to count the social value of private water taps connected to homes if they are preferred for prestige reasons, (2) how to assess husbands' preferences concerning the time savings by wives who previously carried water from more distant sources, (3) how to count preferences based on a respondent's desire to support general community welfare, and (4) how to evaluate a water project when people's preferences may change after the new water system is installed. We argue that policy analysis will be improved by presenting philosophical arguments as to why some preferences should be included in the evaluation and others ignored.

Planning now for irrigation and drainage in the 21st century

Abstract: The theme for the conference was Planning Now for Irrigation and Drainage in the 21st Century. Many of the regions of the Country are experiencing water supply declines and/or increasing competition for water. Planning is required now to assure that adequate water supplies will be available in the future. The impact of irrigation and drainage on water quality is a major concern. This concern must be addressed in order to be sure of that effective irrigation and drainage practices can be used to serve agriculture. Many of the papers directly address some of the issues.

The Bramham Incident, 1980 ‐ An Outbreak of Water‐borne Infection

Abstract: SYNOPSIS AN OUTBREAK OF gastro-enteritis in several villages to the North East of Leeds, England, in July 1980 was rapidly traced to the water supply One of the source boreholes was found to be contaminated by sewage from faulty sewers, via the Magnesian limestone The combination of circumstances which allowed the contaminated water to enter the supply are described, as are the ways in which systems were improved to prevent any similar incident occurring

Water supply and drainage

Abstract: Kaj Ovesen of the Danish Building Institute and former co‐ordinator of the CIB Commission discusses harmonization of the European water and drainage building regulations.

Water balance analysis for Ghana

Abstract: In this study a comparison of the mean monthly values of potential evapotranspirauon (PE) and rainfall is made for Ghana. From this comparison, the quantity of water that actually evaporates from the soils and open water surfaces and transpires from plants, the quantity of water that is stored by the soils, and the surplus water at anyplace and month in the country are known. As rainfall and PE are two independent climatic variables, their annual courses hardly coincide; as a result there are periods in the country when the necessity for water is satisfied by rainfall and other periods when there is scarcity of water. Some months certain places in the country therefore have adequate water supply and others have excess or deficit. There are also extreme cases in which in nearly all the months of the year, rainfall exceeds PE and vice versa.