Showing papers on "Water supply published in 1975"

Control of Schistosoma mansoni transmission by provision of domestic water supplies. A preliminary report of a study in St Lucia.

Abstract: As an experimental control measure to reduce the transmission of S. mansoni, an individual household water supply was provided in 400 houses in 5 rural settlements of the Riche Fond Valley, St Lucia. This population of about 2 000 had previously been dependent for water on infective streams and rivers. Six other settlements in the valley, all provided with limited piped water from public standpipes, served as the comparison area. After 2 years the incidence, prevalence, and intensity of infection with S. mansoni were significantly lower in the household water supply area, whereas all these indices of infection had increased in the comparison area. An adequate, reliable, and convenient supply of water can reduce the transmission of S. mansoni and should be considered as a control measure in other endemic areas.

Spatial Variation of River Water Quality: A Survey of the River Exe

Abstract: River water quality is of considerable relevance to the geographer and a reconnaissance survey of the spatial variation of the specific conductance of stream water within the basin of the River Exe was undertaken by the authors. The spatial pattern defined by the more than 500 samples collected was mapped and an attempt has been made to interpret the results. Much of the variation was closely related to lithology, but land use was also found to exert a significant influence on levels of conductivity. The data collected have also been used to obtain estimates of the magnitude and spatial pattern of annual solute loads and of chemical denudation rates. DURING the past 25 years, increasing attention has been focused upon spatial and temporal variations in the magnitude of streamflow or river discharge in Great Britain. Regional water resource studies have assessed the volumes of run-off available in particular areas, suggesting ways in which water can be stored and regulated.1 Furthermore, the problems of floods and droughts have stimulated the development of techniques for evaluating and predicting floods and low flows.2 Data on the flow of rivers in the British Isles are now available in the Surface Water Yearbook3 and additional information is being collected from several research basins.4 Geographers have been aware of the opportunities and relevance of this field of study and they have themselves made contributions.5 Much less information is available on the quality, as distinct from the quantity of streamflow. Detailed work in this sphere has previously been the province of the chemist and public health engineer and has been primarily concerned with the potability of sources of water supply and the nature and extent of serious pollution and the various possibilities available for the control or alleviation of this problem.6 With the increasing concern over the optimum use and management of water supplies in this country, more interest is being directed towards collection and interpretation of water quality data. River temperatures have already attracted the investigations of several workers,7 and studies of nitrate levels8 and solute transport by local streams have also been made.9 The quality of river water is not without relevance to the geographer, as Douglaso1 has recently emphasized. Water quality constitutes a valuable environmental indicator, reflecting the interaction of the quality of the incident precipitation with the character of the catchment area, the processes operating in the drainage basin, and the influence of man. It is in this context that Perel'manll has promoted the concept of geochemical environments or landscapes whereby geochemical indicators can be used for landscape classification or regionalization. In turn, water quality is an important control on human activity and resource utilization.12 Minimum quality standards exist for the various uses of water13 and severe negative feedbacks can occur where man-induced deterioration in water quality inhibits continued or more intensive use of water I55 This content downloaded from 207.46.13.111 on Sun, 07 Aug 2016 05:15:25 UTC All use subject to http://about.jstor.org/terms D.E.WALLING AND B.W.WEBB resources. Because of the significance to the operation of geomorphological processes, physical geographers have already made considerable progress towards understanding the solution chemistry and water quality of limestone areas.14 However, there is considerable scope for studies in non-limestone areas. For example, spectral analysis has been shown to be a powerful tool when studying temporal variations in solute concentrations,15 and the evaluation and interpretation of spatial variations in river water quality would seem to be another worthwhile theme for investigation. There are many indices of river water quality including, colour, odour, temperature, turbidity, solute content and other chemical and biological parameters, and these will exhibit spatial and temporal variations to a greater or lesser extent. Solute content and the concentration of individual ions provide a sensitive environmental indicator. For example, Miller16 has shown how solute concentrations can vary according to rock type; classic studies in the Hubbard Brook experimental catchment in New Hampshire, U.S.A.17 have stressed the interdependence of concentrations of individual ions and the nutrient cycle; and Skakalskiyl8 has demonstrated how solute concentrations can be related to the magnitude and origins of different run-off components. In addition, many reports exist of the influence of man on these parameters.19 Temporal variations in solute concentrations have been well documented by workers such as Hendrickson and Krieger20 and Hall,21 and spatial contrasts have been discussed on a world scale by Gibbs,22 on a continental scale by Rainwater,23 at the regional level by Douglas,24 and within a drainage basin by Anderson and George.25

Water Supplies for Low-Income Communities in Developing Countries

Abstract: Examination of data on the availability of adequate water supplies in developing countries reveals an alarming state of affairs. This paper presents an analysis of the potential impact of a water supply in a poor tropical community and examines techniques for the quantification of this impact. Special attention is paid to the impact of a supply on the water collection journey (time and energy saving) and to the anticipated improvements in community health. A classification of water-related disease is presented and the effect of water supplies on various water-related infections is analyzed. A comprehensive table, showing the principal features of the water-related diseases, is included. It is shown how the analysis of water supply impacts, and in particular impacts on water collection and health, can facilitate improved designs and more rational resource allocation for water supply programs in developing countries.

A Multilevel Approach to Planning for Capacity Expansion in Water Resource Systems

Abstract: Supply and demand models are developed as aids in planning future water resource expenditures. The supply model yields least-cost schedules of projects to meet assumed levels of demand. The demand model, conversely, allocates available water supplies within a regional input-output economy to most efficiently utilize the available resource. As more and more water is made available at various future points in time, the extra amount will be used for less important and productive uses. However, as additional water supply is planned, the costs of supplying the resources become excessively high, since less efficient supply projects must be built. For these reasons, the supply and demand models are placed in a hierarchical framework whereby the supply/demand projections are adjusted so that the additional costs of supply match the additional economic value of the supply. This requires a formal extension of classical benefit-cost analysis, which is referred to as dynamic benefit-cost analysis.

Individual household water supplies as a control measure against Schistosoma mansoni. A study in rural St Lucia.

Abstract: As part of a programme to evaluate single control measures for reducing the transmission of Schistosoma mansoni, household water supplies were installed in 5 rural settlements in the Riche Fond Valley of St Lucia. About 2 000 persons who previously were dependent on rivers and streams are now receiving safe water at their homes. The systems provide useful design data on individual water requirements in rural areas. This experience suggests that future rural water systems can be designed more economically and efficiently by using consumption rates that are closer to the actual requirements and by eliminating water wastage at the taps.

Household Technology and the Domestic Demand for Water

Abstract: Forecasts of domestic water demand in the United Kingdom-including those used in early regional planning exercises [UK Government, Water Resources Board, 1966, 1970, 1971] -have traditionally been prepared by local supply undertakings or catchment authorities. Traditionally, these demands have been met in full without recourse to rationing through consumption-related pricing policies. The experience of economic growth since 1950 and the costs now anticipated at new supply schemes are currently calling both these traditions into question, as evidenced by the administrative reorganization and discretionary metering powers envisaged in the 1973 Water Act [UK Government 1973]. The contribution of economic principles to efficiency in public water supply management lies in the demonstration of the interdependence of investment planning, pricing policy and demand projections, and of the influence on demand trends of more general attributes of the growth process. These ideas have been propounded in the context of electricity supply [Turvey 1968], and applications to the water industry have been essayed [Warford 1966; Hirschliefer et al. 1972]. The practical value of refining demand forecasts or of regulating household consumption by metering is, however, an empirical issue. Only if a structural explanation of demand can outperform rules of thumb, and only if the benefits from instituting metering outstrip the costs of such a policy, will resource savings be promoted. Evidence on demand behavior in the United Kingdom is necessarily slender, since in only one areaMalvern, in Worcestershire-is usage by individual households metered and subject to pro-rata charges. Much work aimed at the estimation of income and

The politics of London water.

Abstract: TODAY Londoners enjoy a water supply which has attained a very high standard of both quality and quantity. But this situation has not come in a day. The supply of water in London has always been the subject of political contests of some kind and there is a continuity in London's fight for water. Londoners had to fight protracted battles for control over their water supply in the nineteenth century. In the twentieth century the demand has occasionally come for the organisation of water supply in Greater London under a unified democratic management, but nothing has actually emerged until very recently, when Greater L

Multiobjective analysis in water resource planning and management: A framework for policy evaluation

Abstract: A multiobjective framework for the planning and management of a regional water resource system is presented, considering the conflicting objectives of environmental quality and the cost of water resource development. The regional water resource system is a complex, large-scale system and includes a number of proposed and existing water resource facilities (both water supply projects and wastewater treatment plants.) Treatment alternatives available at each wastewater treatment plant include secondary treatment, tertiary treatment, and recycling of treated effluent (at industrial plants only).

Determining Optimal Well Discharge

Abstract: The cost of pumping ground water is a major factor in water supply. It is necessary to pump a given well at the discharge that maximizes the net benefit of the operation. Previous criteria ignored the economic aspects of the analysis; the writer submits a detailed criterion for obtaining the best discharge for a well. A computer code is included along with an example of the analysis.

WRRCTR No. 94 Water Recycling of Sewage Effluent by Irrigation: A Field Study on Oahu

Abstract: The research reported herein was funded by the Board of Water Supply and the Department of Public Works, City and County of Honolulu, and was conducted with the cooperation of the Hawaiian Sugar Planters' Association and the Oahu Sugar Company.

Water pollution control in low density areas

Abstract: Twenty-eight papers are included on water pollution in the rural environment. The book is divided into six sections: land treatment of wastewater, septic tanks and their effects on the environment, groundwater problems, rural water supply problems, non-point pollution, and low-cost wastewater treatment facilities for rural areas. (JGB)

Economic Assessment of an Activity Analysis Model for Water Supply Planning

Abstract: A mathematical model for assessing the water supply alternatives with the reuse option is described, and its potential to yield results useful for economic analysis and policy making is explored. The results of the model for Salt Lake County, Utah, used as a case study area are shown. The relative marginal values reflecting quality and accessibility of various sources can aid in planning future water resource development. The supply curves derived from the model are useful for pricing policies. The relative locational advantages of water and waste water treatment plants enter importantly into capacity expansion decisions. The least cost solution indicates the necessity of a facility to recycle waste water for municipal use under increased demand conditions.

Waterfowl refuse effect on water quality: I. Bacterial populations.

Abstract: In recent years, it has become obvious that the fixed amount of available water must be reused more and more often as the demand for water increases. Such a situa tion may result in an accumulation of un desirable substances in the water, and iden tifying the sources of unwanted or other extraneous material in water is becoming increasingly essential. This is particularly true in areas of low precipitation, such as the southwestern U. S. In these areas, all potential, major factors affecting water quality should be studied, and their effects should be analyzed. The purpose of this project was to de termine what effects, if any, a major wild life refuge, specializing in waterfowl man agement, would have on water quality within the refuge and on water leaving the refuge. The results would be useful in the management of any refuge of this type and also could prove valuable in determining the effects of duck and goose farms on water quality. This paper considers various bacteriologi cal parameters of the water affected by the refuge. The physiochemical characteristics of the water have been reported elsewhere.1 The Bosque del Apache National Wild life Refuge located on the Rio Grande River system, the most important water source for much of New Mexico, was se lected for this study. The refuge is main tained by the Bureau of Sports Fisheries and Wildlife of the U. S. Department of the Interior. The major part of the Rio Grande River originates from precipitation in south ern Colorado and northern New Mexico. The river receives scant recharge waters throughout most of its length in New Mexico. The water is reused several times within New Mexico for such activities as farming, municipal and industrial needs, and recreation. Any discharge into the Rio Grande that might produce deleterious ef fects on water quality could have serious consequences. The northern limit of the Bosque Refuge is about 12 miles (19.32 km) south of the city of Socorro, N. M ex. [The southern end of the refuge is another 12 miles ( 19.32 km) farther south.] The refuge is an ex cellent study area for several reasons. First, water flows through a controlled system of canals and ditches. Second, the use of fertilizers on that part of the refuge that is farmed is carefully controlled. Third, precipitation is light [annual average of about 8.5 in. (21.59 cm)], particularly dur ing the time of the year when the water fowl are present; any dilution effects are thus reduced. The largest bird populations occur from late October to early March; average figures are 10,500 sandhill cranes, 2,000 Canada geese, 8,300 snow geese, and 26,500 ducks. Geldreich2 has suggested that wildlife refuge areas receive significant fecal con tamination during periods of intense water fowl use and that the resulting pollution would be concentrated in these areas. Any bacterial contaminants, including patho gens, may survive for long periods in bot tom sediments. Thus, refuge waters should not be used for recreational functions, which could lead to resuspension of the bacteria. The parameter used for evaluating the effect of the refuge on the nearby water supply was the total count of coliform bac teria, which are currently considered im portant in water quality evaluation.3 In addition, the number of enterococci was also used to evaluate the water quality,4

Water storage refill system

Abstract: A water system for a mobile vehicle has an intermittent external source of water and uses water from an internal storage tank to provide a continuous supply of water. A water storage refill system automatically refills the internal storage tank whenever there is an external source of water. An inlet conduit is detachably connectable to an external water supply and in communication with the internal storage tank and the remainder of a plumbing system. An electrically actuated valve in the inlet conduit controls the flow of water from the external source of water to the internal storage tank in response to sensing devices indicating the need for water in the storage tank and the availability of water from the external water source.

On the peak‐load pricing of urban water supply

Abstract: Peak-load pricing through seasonal price increases without changes in metering and billing practices may produce distortions in efficiency and equity in urban water systems. Demand management models using parameters to evaluate the effect of seasonal price policy upon maximum day sprinkling demands may be misleading because of behavioral constraints to price responsiveness. Proposed are alternative pricing schemes that are likely candidates for improving the operating cost structure and design capacity of water supply systems without violating popular notions of equity.

Watering-equipment for potted plants - consists of primary, enclosed water-container with water-pipe and air-pipe joined to second open container

Abstract: The first enclosed water-container is positioned on a higher level than the plant-pots and is connected to a second, open water container lower down. A water-pipe extends in both containers to nearly the bottom, so that each end is immersed in the second or first container. The air-pipe begins in the air-space of the first container, and ends on the water-level of the second container and exerts suction. The second water container is connected by means of a water supply device to one or more distributors which, for example, can be one or more clay tapers situated in the centre third of the nutrient in each pot. Each taper is horizontal. The water-level in the second container is from two to eight centimetres higher than the distributor device. The pots may be arranged in a battery-container.

Peak-Load Pricing Through Demand Metering

Abstract: There has been a lapse in the discussion of demand metering of water supply since the AWWA committee meeting in 1959, the results of which were reported in the Journal in December of that year. However, since that time the economic and utility literature on the subject of peakload pricing of urban public services has not been scarce. Utilities other than water supply have incorporated temporal variations in pricing on daily, seasonal, or hourly bases; it appears that the chief reason for the delay of the water-supply industry in adopting such measures is that proper instrumentation has not yet been developed. This article attempts to show the benefits of demand metering, the latest efforts in research and development in this area, and the structure of a proposed tariff. It suggests extending the range of choice of billing options for urban waterutilities managers. Within recent years several significant studies have been published concerning the effect of price on the quantity of water consumed by residential customers for household and sprinkling uses. Wong,1 in a study of water demands in the Chicago metropolitan area, reviews the literature and cites extensively from it. The dependence of consumption upon price introduces a new dimension of complexity into the problems of designing urban water systems, rate schedules, and revenue projections.

Water reuse: A flexible and efficient management alternative for municipal water supply

Abstract: A comparison between the fixed schedule of planned expansion of water supply sources and an alternative expansion program based on a short-term decision from monitoring reservoir levels, water use, and streamflows and employing water reuse capacity and new source development is simulated for the Colorado Springs, Colorado, municipal water system. For this complex, fast growing system with supply based on streamflows and some current reuse capacity the alternative plan postpones major new development an average of 14 years at a cost at present value of half the original planned expansion.

Systems evaluation of village water supply and treatment in Thailand

Abstract: A systematic evaluation was made of 165 village water supply and treatment systems in Northeast Thailand for studying problems involved in the design, construction, operation, administration, and financing of such systems. The evaluation included 1 year of field data collection covering system operation by village operators. This is believed to be the first such evaluation of the effectiveness of a rural water supply development program. Findings include quantification of strengths and weaknesses pertinent to management, and recommendations are developed for guiding governmental agencies operating such programs and international agencies participating in their planning and financing.

Water for the Southwest: Historical Survey and Guide to Historic Sites

Abstract: In this document, a brief narrative history of the effects of the people who lived in the area (prehistoric Indians, the Spanish, and the Anglo-Americans) to secure and maintain water supply systems presented and illustrated by contemporary drawings and photos. This narrative history serves as an introduction to documentary and pictorial summary of early water supply systems in the Southwest. Sixty sites which represent locations of historical and technological significance are presented with supporting references, photos, and drawings. Included in the 60 documentations are sites in Arizona, Colorado, New Mexico, Texas, and Utah.

Screening Model for Conjunctive-Use Water Systems

Abstract: A network model for preliminary screening of alternatives for water supply from conjunctive use of groundwater and surface water in a river basin is presented. The results from the analysis for an example river basin demonstrate how the network analysis procedures can be used to determine optimum investment plans, to test policy constraints, and to develop policies for future development and future constraints.

Models of Land and Water Allocation To Improve Environment and Water Quality Through Soil Loss Controls

Abstract: A model is developed that is applicable to all agricultural land in the United States. The model includes 223 producing areas, 1891 land resource areas, and 51 water supply regions. Different cropping systems and technologies are defined for each crop and livestock system in each of 1891 land resource regions. Hence the programing model is of very large scale, since it also includes a transportation submodel and market regions. As a means of water quality improvement, limits are placed on the per acre per year soil loss as a means of reducing sedimentation and the transport of nitrogen and phosphates into streams. A nitrogen balance equation limits fertilizer purchases and forces utilization of livestock wastes in the region. The model forces a land use system and set of technologies over the country and interregionally that has soil loss unrestricted, at 10 tons per acre, at 5 tons per acre, and at 3 tons per acre. The unrestricted and 5-ton limits are reviewed in this paper in relation to impacts on soil loss (reduced about 25%), crop distribution, technology, water use, and farm prices.