Service Reservoirs Research Articles

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates.

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.

Isolation of Aeromonas spp. from an unchlorinated domestic water supply.

The recovery of Aeromonas spp. from the unchlorinated water supply for a Western Australian city of 21,000 people was monitored at several sampling points during a period of 1 year. Membrane filtration techniques were used to count colonies of Aeromonas spp., coliforms, and Escherichia coli in water sampled before entry to service reservoirs, during storage in service reservoirs, and in distribution systems. Aeromonas spp. were identified by subculture on blood agar with ampicillin, oxidase tests, and the use of Kaper medium and then were tested for production of enterotoxins and hemolysins. During the same period, two-thirds of all fecal specimens sent for microbiological examination were cultured on ampicillin-blood agar for Aeromonas spp. Recovery of Aeromonas spp. from water supplies at distribution points correlated with fecal isolations and continued during autumn and winter. Coliforms and E. coli were found most commonly in late summer to autumn. This pattern differs from the summer peak of Aeromonas isolations both from water and from patients with Aeromonas spp.-associated gastroenteritis in Perth, Western Australia, a city with a chlorinated domestic water supply. Of the Aeromonas strains from water, 61% were enterotoxigenic, and 64% produced hemolysins.

Optimal Layout for Branching Distribution Networks

A branching network consisting of several sources and demand nodes is considered to find its optimal geometrical layout. Initially a one‐source two‐demand‐node network is considered and for it, optimality criteria are developed, a procedure is evolved and then illustrated through an example. It is shown that the optimal layout of one‐source two‐demand‐node network is mostly the one in which the demands of the two demand nodes are first jointly transported to a junction point through one link and then from the junction point to the two demand nodes through two separate links. The junction point generally lies within the triangle formed by the nodes but exceptionally may coincide with one of the nodes. The procedure is then extended to a multiplenode system consisting of several sources and demand nodes and can be applied to water supply systems for large urban areas in which the several service reservoirs are supplied from one or more sources.

Optimal Irrigation Distribution Systems with Internal Storage

ABSTRACT A method was developed to specify the optimal sizes and locations of farm service reservoirs within an irrigation system. The resulting optimal plan is the least cost system for temporarily storing water so that irrigators can obtain irrigation water upon demand during a fraction of each day and thereby use water more effectively. The procedure was effective in incorporating specified constraints such as reservoir location, use of runoff water, and water cost into the analysis.

THE APPLICATION OF OPTIMIZATION TECHNIQUES IN THE PROFESSIONAL PRACTICE

Abstract The paper discusses practical experience of incorporating optimization techniques in the design process. Methods of optimization often assume that a continuous spectrum of solutions is available to the designer, but in practice the engineer is generally confronted with a finite set of discrete alternatives. The ease and merit of applying experience orientated computations with a pre-planned lattice search method is demonstrated. This approach is illustrated through its application to a specific structural element within a building; and the results are compared with those obtained from a direct search method which incorporates an acceleration strategy and which assumes a continuous spectrum. The application of the method to the synthesis of reinforced concrete rectangular service reservoirs is considered. The results and experience gained from the use of this algorithm indicates the difficulties and advantages which designers have experienced in incorporating optimization within the decision process.

Optimization in Design of Hydraulic Network

A new method termed as equivalent diameter method for the direct least-cost solution of pipe sizes of the different branches of the network consisting of pumps, elevated service reservoir and the n...

Reconstruction of the Halifax High Service Reservoir

Journal AWWAVolume 39, Issue 6 p. 503-514 Article Reconstruction of the Halifax High Service Reservoir R. M. Doull, R. M. DoullSearch for more papers by this authorJ. D. Kline, J. D. KlineSearch for more papers by this author R. M. Doull, R. M. DoullSearch for more papers by this authorJ. D. Kline, J. D. KlineSearch for more papers by this author First published: 01 June 1947 https://doi.org/10.1002/j.1551-8833.1947.tb17689.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume39, Issue6June 1947Pages 503-514 RelatedInformation

Surveys for water conservation

Abstract Water conservation schemes are carried out for various purposes, chief of which are water supply, irrigation and development of hydro-electric power, and it is the duty of the surveyor to supply the engineer with all the data to be collected in the field which are required to produce the final scheme. These data include, amongst others, discharge of streams, rainfall data, evaporation data, surveys of catchments, location of dam sites, including provision for spillways, measurements of storage capacities, surveys for pipe lines, investigation of access for various proposed works, location of irrigation channels, power transmission lines, service reservoirs, soil and timber surveys, etc.

Water Supply of London

IN a lecture delivered before the Junior Institution of Engineers on Jan. 17, Mr. G. Andrew-Marshall gave some interesting figures indicating the immensity of the responsibility involved in undertaking the supply of water to so great an area and population as is comprised in the district served by the Metropolitan Water Board. Thus the area supplied is about 560 square miles in extent; the population 7,381,000; and the quantity of water distributed last year was 100,723 million gallons, the average daily supply being 276 million gallons; a little more than the half of which quantity was equivalent to the combined supply for Manchester, Liverpool, Birmingham, Sheffield, Nottingham, Leeds, and Brighton. The net amount received for water rental amounts to about £4,500,000 a year, and the capital debt is £53,856,000. The number of officers employed by the Board is about 950 and of workmen 4290. The capacity of the storage reservoirs is 19,657 million gallons, and of service reservoirs there are 92, holding 321 million gallons; there are 176 acres of filter beds; about 7000 miles of mains, and a total horse-power of 27,270 is required to pump water through the system.

Increasing the Water Supply of Washington, D. C.

That the city of Washington is increasing its water supply is not nearly so remarkable as that it has not increased it since the present supply was built. A brief mention of the present system, because of its intimate relation with the new system now being constructed, may be of interest. Back in 1859 the first water was turned into the conduit to supply a population of 58,000. The estimated daily capacity of the aqueduct was 67? million gallons or sufficient to give every being in the city a quantity of water that even some of our moderns, accustomed to waste it, could not possibly have consumed. The vision of the engineers who built this system is further emphasized by the fact that, at the time of its completion, the 9-foot diameter supply conduit was reduced to a 12-inch diameter main to supply the entire city, and the same conduit now supplies a population increased over 800 per cent. The present system consists of a dam across the Potomac river; a circular masonry conduit 9 feet in diameter and 12 miles long having a fall of 9 inches to the mile, 3 storage and sedimentation reservoirs, a tunnel 4 miles long under the city, a pumping station, a slow sand filtration plant of 29 one-acre beds and a clear water reservoir. In addition there are the distribution mains, pumping stations and high service reservoirs. The water supply and purification works are vested in the Chief of Engineers, United States Army, while the distribution is vested in the city government. After various projects for new supplies were investigated Congress, in 1921, appropriated funds to begin the construction of an increased water supply. This project takes its supply from the Potomac river through a new intake gate house about 100 feet above the present intake at Great Falls, Md.

Lining and Covering of the High Service Reservoir at Quincy Illinois

Journal AWWAVolume 16, Issue 6 p. 769-777 Article Lining and Covering of the High Service Reservoir at Quincy Illinois† Paul Hansen, Paul HansenPearse, Greeley and Hansen, Engineers, Chicago.Search for more papers by this author Paul Hansen, Paul HansenPearse, Greeley and Hansen, Engineers, Chicago.Search for more papers by this author First published: 01 December 1926 https://doi.org/10.1002/j.1551-8833.1926.tb12593.x †Presented before the Illinois Section meeting, March 24, 1925. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume16, Issue6December 1926Pages 769-777 RelatedInformation

The Effect of Covering a Service Reservoir

It is hardly necessary to say that no one at the present time expects to hear of such highly developed animals as fish or eels in a municipal water supply, especially after it has been filtered, yet in талу communities where filtration has been adopted the water is served to the consumer from an open reservoir, thus permitting all manner of dust, droppings from birds, insects, microscopic growths and many other influences tending toward deterioration, to cause much trouble and anxiety. Although it may be possible to account for these various troubles and it may be shown that the water has been filtered properly, yet the layman will be of the opinion that the supply is not cared for in the proper manner and hence the usual complaint, whereas if the reservoir had been covered or protected in some way, everything would have been satisfactory. The open surfaces of water, whether in service reservoirs, clearwater tanks or basins or channels, lend themselves primarily to the introduction and development of algae and insects. The latter lay their eggs on the borders of the open bodies of water, in which when hatched the larvae spend one part of their existence as freeswimming animals before reaching a further stage in their development, thus permitting, sometimes, the consumer to obtain some of the larvae from the spigot in his home. Fortunately, many of these larvae and algae do not make the water-mains their permanent abode, and hence may be regarded as occasional passengers on an unknown journey. Especially is this so with algae, since they thrive best in the sunlight, and yet it should not be forgotten that such forms as Sponge and Crenothrix are met primarily in iron pipes. As a result of the presence of algae in water basins, the water becomes subject to disagreeable tastes and odors resulting from the growth and decay of the organisms. Again, small organisms visible to the naked eye, such as Daphnia and Cyclops cause much worry on the part of the consumer when seen in the glass of water as

Notes on the use, construction, and cost of service reservoirs in New South Wales

Notes on the use, construction, and cost of service reservoirs in New South Wales