bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Thames Water Ring Main: The Future
Authors: Bensted I. H 
Published: July 2007

ABSTRACTCommissioning of the Thames Water ring main Phase 2 tunnels in the spring of 1994 signalled an important milestone for major investment on London's watertreatment and trunk distribution systems. This included not only the ring main itself, but also the progressive installation of advanced water treatment processes in the water‐treatment works supplying the city, due for completion at the end of 1998.This paper reviews the benefits of the ring main and looks at future developments, focused largely in local distribution rehabilitation and leakage control. The objectives and benefits of future possible extensions of the ring main are discussed, and a configuration is put forward as potential for development in the long term.
Gross Solids' Movement in Sewers: Laboratory Studies as a Basis for a Model
Authors: Davies J. W , Butler D. , Xu Y. L 
Published: July 2007

ABSTRACTA simple model of gross solids' movement in sewers is proposed, based upon the results of studies of part‐full pipe flow in two laboratory installations, under steady and unsteady flow conditions. The model covers advection and deposition, and is intended as one component in a comprehensive model of the behaviour of gross solids in sewers. Such a model is needed because gross solids are not included in the currently available sewer‐flow quality models, even though they can cause pollution which is of particular concern to the publicThe paper describes the laboratory studies and their results. It sets out the principles of the proposed model and explains why these differ from existing models of dissolved and fine suspended pollutants.
Evaluation of Lake Vyrnwy within the Integrated Water Supply Systems of North West Water
Authors: Ringham J. E. , Walker S. , Wyatt T. 
Published: July 2007

ABSTRACT In 1992, the National Rivers Authority published a discussion document on the National Water Resource Strategy which highlighted the future probability of a water‐supply deficit in the south‐east and a surplus in the north and west of England and Wales. One suggestion for rectifying this imbalance was to divert Lake Vyrnwy water which, at present, supplies Liverpool. This would allow further regulation of the River Severn, and subsequent transfer to the River Thames. Joint investigations by the National Rivers Authority and North West Water have established the implications of this diversion on the existing water resources and supply systems of North West Water.The studies considered (a) the relationship between increased regulation releases, and reduced direct supply rates from Lake Vyrnwy, (b) the investment and operating cost implications of replacing Lake Vyrnwy supplies from sources within the southern command zone or by transfer from the northern command zone, and (c) the potential operational difficulties.The paper describes how each of these aspects has been addressed. The results demonstrate the necessity of evaluating Lake Vyrnwy as a component of the integrated water supply systems of North West Water, and of other parts of the country.
The Management of Sediment in Reservoired Catchments
Authors: White P. , Labadz J. C. , Butcher D. P. 
Published: July 2007

AbstractThe rates of sedimentation in Yorkshire reservoirs are high for the UK but low compared with those reported globally. Whilst not likely to jeopardize supply, the behaviour and properties of reservoir sediments have implications for the quantity and quality of the water.Data suggest that the use of control and diversion structures reduces average sedimentation by 53m3/km2 per annum in the case of residuum lodges, and also modifies the nature of the sediment considerably, tending to allow the finer, organic particles into the reservoir. Trapping may be minimized by the diversion of high flows where such facilities exist, or by maintaining water levels at the maximum possible in supply reservoirs.Management strategies to reduce sedimentation would, in many cases, require fairly simple routine maintenance of existing structures. The short‐term cost of discarded water must be weighed against the longer‐term benefits of improved quality and reservoir capacity.
The Microbiology of Lubricants and Oils for Water Supply Applications
Authors: Sidorowicz S. V. 
Published: July 2007

AbstractRecent work in the US has shown that contact between lubricants and oils and drinking water can promote the growth of heterotrophic micro‐organisms. It is unlikely that these species are pathogenic, and therefore harmful to man. However, the hygienic status of water distribution systems could be affected, leading to higher heterotrophic plate counts during routine sampling. Experimental work has been undertaken to study the microbiological impact of a range of lubricants and oils on drinking water. The methods have been based on an existing procedure for the assessment of the growth potential of drinking water, i.e. the ‘assimilable organic carbon’test. The results of this work could serve as the basis of a future standard method for the rapid and inexpensive screening of oils and lubricants for their microbiological suitability in potable‐water applications.
The Removal of Bromate from Potable Water Using Granular Activated Carbon
Authors: Mills A. , Belghazi A. , Rodman D. , Hitchins P. 
Published: July 2007

AbstractBromate in drinking water, at a level of microgrammes/litre, is a problem in ozonated waters but can be adsorbed, to a certain extent, by granular activated carbon. The adsorption capacity of granular activated carbon for bromate is significantly lowered when there are high concentrations of other anions, most notably chloride and sulphate, present in the water.
Developments in UK Reservoir Engineering and Management
Authors: Johnston T. A. , Millmore J. P. , Macdonald A. 
Published: July 2007

AbstractThis paper presents an overview of recent developments in reservoir construction and maintenance in the UK. It highlights the increasing importance of environmental issues to successful scheme promotion and provides advice on the key issues which need to be addressed. Research into dam safety is leading to further guidance for engineers in assessing existing structures. Comments are made on future capital expenditure on the existing stock of dams, and the status of dam safety legislation is reviewed.
The Effect of Agitator Impeller Design on Maximum Shear Stress, and the Resulting Impact on the Flocculation Process
Authors: Griffiths S. 
Published: July 2007

AbstractAlthough it is extensively researched, flocculation in the water‐treatment industry lacks a design procedure to assess accurately the performance of the different types of agitator impeller which are available. New high‐efficiency, hydrofoil‐type impellers offer substantial potential for flocculation duties in many areas, provided that they are applied correctly. This paper highlights the importance of the ‘velocity gradient’and the distribution of shear within the agitation system. The objective of the paper is to help engineers to evaluate different types of proprietary impeller designs, using various techniques to examine the shear distribution applied to the system.
Implementing Environmental Management Systems in the Finfish Aquaculture Industry
Authors: Gavine F. M. , Rennis D. S. , Windmill D. 
Published: July 2007

AbstractEnvironmental management systems are being implemented in many sectors of industry in order to assist organizations to (a) comply with legal requirements minimizing impacts on the environment, (b) reduce waste, and (c) gain an advantage in the market place. This paper provides guidance on the elements which should be incorporated into an environmental management system for finfish aquaculture operations in the UK.
The Channel Tunnel's Marine Works for Spoil Disposal
Authors: Maddrell R. J. 
Published: July 2007

AbstractAfter many trials and about 10 000 years, land access between Britain and the Continent was re‐established in 1991 by the Channel Tunnel link, owned by Eurotunnel and built by a consortium of contractors, Transmanche‐Link.The Channel Tunnel Act allowed Eurotunnel to construct two 8.5 m dia. running tunnels and a 5.4 m service tunnel, with the chalk spoil disposed of as a platform at the toe of Shakespeare cliff. The platform was on the critical path because it was also the main marshalling area for tunnel construction.Spoil disposal was a major logistic and planning issue and required nine consents from various statutory bodies. Environmental issues were important and formed part of the 121 design‐related studies which included site investigations.About 5 million m3 of spoil were disposed of in five sequentially developed lagoons, all of which had to be closed before the spoil could be placed. The completed platform, now known as Samphire platform, is a nature area with a small area for Eurotunnel's cooling plant.
A Simple Aid for Designing Sewers
Authors: Broome J. M. 
Published: July 2007

AbstractA method for constructing design charts for the rapid selection of sewer diameter and gradient is described. A variety of design criteria for sewer capacity and minimum gradient can be incorporated in the chart, which may be adapted for different ranges of pipe diameter and material. The use of the chart should ensure that the most economical combination of pipe diameter and gradient can be chosen without the need for calculation.
River Thames Flood Hydrology Design Curves
Authors: Dunsmore S. J. 
Published: July 2007

AbstractA quick method of defining design peak flows and hydrographs for any point on the River Thames between Days weir and Teddington is offered as a design tool for flood analysis. This paper presents the findings of a flood frequency and flood hydrograph analysis for the River Thames. The results were used in a hydraulic analysis of the river and its floodplain at Reading, but showed a wider application of the method on the river.
Sewage Sludge Recycling to Agricultural Land: the Environmental Scientist's Perspective
Authors: Towers W. , Horne P. 
Published: July 2007

AbstractDuring the next fifteen years, the recycling of sewage sludge to agricultural land will increase significantly in Scotland as a result of EC regulations. This paper describes how soils and related environmental data around Edinburgh can be interrogated and interpreted to assess (a) the suitability of land for sludge utilization, (b) the risk of water pollution in relation to different soil conditions, (c) the ability of soils to adsorb potentially toxic elements in the sludge to prevent transfer to water or plants, and (d) the operational security and environmental sustainability of sludge recycling. The interpretations can make a valuable contribution to the appraisal of sludge disposal policy and implementation, and provide a framework for technology transfer between engineering, environmental and agricultural interests.
Managing Emergencies: Be Prepared!
Authors: Buckley C. B. 
Published: July 2007

AbstractThe successful management and resolution of emergencies affecting water quality is dependent upon easily accessible and well‐documented, user‐friendly information systems to support the decision‐making process. Well‐rehearsed emergency procedures must remain a vital component in the liaison and communication matrix of all organizations to ensure that the emergency is being managed in a competent and professional manner, particularly when public health is at risk.Careful planning is needed to ensure that the necessary facilities and resources are readily available, and this aspect may have significant budgetary implications. Arrangements, to ensure that staff (at all levels) are fully aware of their responsibilities and roles during emergencies, must be secured by a well‐structured training programme, supplemented by periodic refresher courses and planned exercises accompanied by structured debriefing sessions.
Shipping and Handling of Pesticide Cargoes: the Need for Change
Authors: Johnston P. , Marquardt S. , Keys J. , Jewell I 
Published: July 2007

AbstractOf all the dangerous goods carried at sea, pesticide cargoes are unique in the dangers which they pose to the environment. In 1991, the UN International Maritime Goods Code was amended to require that specified chemicals be labelled as ‘marine pollutants’. In addition, packaging must now allow for immersion in seawater and include attempts at salvage. The potential hazards of pesticide cargoes have been illustrated by a number of accidents involving shipping and there is an urgent need to expedite the provisions of the code. Also, many pesticides which are exported are not registered for use in the country of origin. A good case exists for linking the provisions of the code to the registration process and to the ‘prior informed consent’procedure and developing ‘convention’.
Tradeable Rights for Water Abstraction
Authors: Streeter R. 
Published: July 2007

AbstractThe Environment Agency has a statutory duty to secure the proper use of water resources, which is now considered inter alia to include an economically efficient allocation of resources as far as is possible within the current legislation. This paper considers the practical extent to which water rights can be traded within the existing system of regulation as a means of (a) improving the economic efficiency of resource allocation, and (b) satisfying customer demand for additional supplies. Outline proposals are also made for deregulation of current legislation to encourage further trading through less restrictive regulation.
Recent Developments in the Biological Filtration of Sewage to Produce High‐Quality Nitrified Effluents
Authors: Boon A. G. , Hemfrey J. , Boon K. , Brown M. 
Published: July 2007

AbstractThe biological filtration of sewage remains the process which is most commonly used for small works in rural areas throughout the UK. In many cases, the need to produce an effluent of high quality with full nitrification is essential in order to comply with the standards set by the Environment Agency. Traditionally, design loading rates of biological filters have been based on historical experience of performance, and on relatively short‐term statistical evaluation of the performance of a large number of treatment works, using average and maximum values for flow and loading rates. Many works which were designed on such information have failed to nitrify consistently, particularly during the winter and spring months.This paper describes the detailed evaluation of six full‐scale, biological‐filtration sewage‐treatment works over a period of two years, in which there were significant changes in sewage flow rate, composition and temperature, from summer to winter. The key parameters which influence the production of high‐quality nitrified effluents were determined. The conclusions are used to provide a detailed guide on the design of conventional‐media biological filters to produce, consistently, fully‐nitrified effluents.
The Benefit: Cost Analysis of River Maintenance
Authors: Dunderdale J. A. L. , Morris J. 
Published: July 2007

AbstractRiver maintenance, involving vegetation control and channel clearance, is carried out to facilitate flood alleviation and land drainage; increasingly there is a need to justify this expenditure against the benefits obtained. This paper presents the results of a study which was carried out to assess the economic performance of river maintenance on selected rural sites in England and Wales. The evaluation methods have been simplified to provide standard data and routines for river maintenance justification in the form of guidelines, elements of which have been incorporated into‘flood defence management system’methodology.
The Impact of Micro‐Hydropower on the Aquatic Environment
Authors: Copeman V. A. 
Published: July 2007

AbstractThis paper considers the impact of‘run‐of‐river’micro‐hydropower on the aquatic environment, focusing on the Afon Ty'n‐y‐Ddol in Snowdonia. Hydrological modelling of the abstracted reach shows that up to 50% of the annual flow is abstracted for power generation. A sediment and benthic macro‐invertebrate study down the reach showed no significant adverse consequences due to the altered hydrological conditions when subjected to individual taxa, diversity, or quality index analysis. A reduction in‘average score per taxa’immediately below the abstraction point may require further research.
Quantitative Risk Assessment for Incineration: Is It Appropriate for the UK?
Authors: Harrop D. O. , Pollard S. J. T. 
Published: July 2007

AbstractThe economic benefits of waste‐to‐energy plants are well known, but what are the environmental concerns? Public anxiety with regard to the development of incineration plants has focused attention on the need for informed and transparent assessment procedures based on sound science, to ensure that the impact of such developments is acceptable from an environmental perspective.
Reconstruction of Bray Weir on the River Thames
Authors: Higgs A. W. , Campbell G. G. , Dunn P. J. 
Published: July 2007

AbstractBray Weir on the River Thames near Maidenhead was refurbished during the summers of 1993 and 1994. The existing structure, which had become unsound and unsafe to operate, was replaced by nine vertical‐lift (or buck) gates. Construction works within a cofferdam and utilizing floating plant were undertaken in two phases. Following demolition of the existing weir, a network of reinforced concrete beams was supported on new driven piled foundations. Twin leaf gates slide in guides and span between new steel A‐frames, and are lifted by pairs of threaded spindles rotated by actuators operating through gearboxes. Fine flow control is achieved by allowing overtopping of the upper leaves of the gates. Following commissioning, operational difficulties resulting from seal vibration and excessive friction on the spindles necessitated design modifications.This paper outlines a brief history of the site, the design options considered, the contract strategy employed, and includes a description of the construction phase and subsequent postcommissioning aspects.
The Wansbeck Barrage Scheme: Twenty‐One Years of Environmental Impact
Authors: Worrall F. , McIntyre P. 
Published: July 2007

AbstractThe Wansbeck barrage (in Northumberland), which was completed in 1975, was envisaged as a means of removing unsightly saltmarsh and creating an amenity lake and country park. This study examines the effect of the scheme on the estuarine environment and focuses on (a) the nature of the habitat, (b) the rate of sedimentation, (c) the control on water quality within the impoundment, and (d) amenity use.
Pumps as Turbines and Induction Motors as Generators for Energy Recovery in Water Supply Systems
Authors: Williams A. A. , Smith N. P. A. , Bird C. , Howard M. 
Published: July 2007

AbstractPressure‐reducing valves, which dissipate energy, are often used in water supply systems to regulate the downstream pressure levels. If a reverse running pumpset is installed alongside such a valve, most of the dissipated energy can be recovered.This paper describes a system of this type which has recently been installed by North West Water, with advice and specialized equipment supplied by the Nottingham Trent University Micro‐Hydro Group. The power produced by the energy‐recovery system is used to run and monitor a remote potable‐water dosing plant.
Refurbishment of Five Ancient Weirs on the River Avon
Authors: Hindle J. , Kirby I. , Treadgold P. 
Published: July 2007

AbstractThis paper reviews the work which was carried out during the Avon Weirs Project ‐ from feasibility through site investigation and detailed design, to construction. The design included measures to (a) ensure the stability of the structures against uplift and piping failure, and (b) provide protection to the bank and bed of the river. In addition, the design satisfied the requirement to provide fish passes at all weirs and canoe ramps at Evesham and Chadbury weirs. Most of the funding was provided by the River Avon Weirs’Trust.
Stable Foams and Sludge Bulking: The Largest Remaining Problems (Abridged)
Authors: Wanner J. 
Published: July 2007

AbstractThe separation of activated sludge in secondary settling tanks is the crucial step in biological wastewater treatment from the point of view of both final effluent quality and operation of the aeration plant. The sludge‐separation problems of bulking and foaming are connected with an excessive growth of filamentous micro‐organisms in the biocenosis of activated sludge.This paper (a) describes the methods which are used for the quantification of activated‐sludge separation problems, and (b) summarizes the design recommendations for bulking and foaming control.
Grey‐Water Reclamation for Non‐Potable Re‐Use
Authors: Surendran S. , Wheatley A. D. 
Published: July 2007

AbstractDirect water recycling has become an important part of water conservation in the dry areas of the world and is now being seriously considered for the UK. This paper reviews current demands in large buildings and balances these against non‐potable re‐use. Work is also described on the development of a sustainable low running cost treatment unit. Results are presented from a 751/day prototype biological process operated with a synthetic sewage, which achieved a near potable standard at a cost of 25 p/m3. The design, performance and costings of a 40 ‘population equivalent’demonstration unit are also given.
The Effect of Regional Factors on Leakage Levels and the Role of Performance Indicators
Authors: Skipworth P. J. , Saul A. J. , Machell J. 
Published: July 2007

ABSTRACTIn 1997, the Government introduced mandatory leakage targets for water companies, which were designed to (a) preserve water resources, (b) guarantee security of supply, and (c) promote efficiency within the water industry. It is intended that each target should reflect the individual situation of the company and that the targets should be achievable within reasonable economic constraints.This paper examines the numerous factors which affect leakage levels and describes how these vary regionally. The evidence demonstrates that a company's level of leakage is dependent upon the local situation and that, at present, there is no basis for comparison which ensures equality in the stringency of leakage targets.
Computational Fluid Dynamics and the Design of Sewage Storage Chambers
Authors: Stovin V. R. , Saul A. J. 
Published: July 2007

AbstractRecently in the UK, there has been significant interest in the design of combined sewer overflow chambers and storage tanks. This paper describes an extensive laboratory and computational fluid dynamics study into the hydraulic performance and sediment retention efficiency of tanks. The work has shown that (i) it is possible to predict the flow field which is measured in the laboratory using computational fluid dynamics, and (ii) a critical bed shear stress may be used to determine the extent of sediment deposition. Subsequently a bed shear stress model and the particle tracking routine in ‘FLUENT’have been used to compare the sediment retention efficiency of eight different chamber designs. The results showed that the length to breadth ratio of the chamber was the most important parameter to influence sediment deposition, and that changes to the benching and longitudinal gradient of the tank had minimal effect.
Predicting the Mean Annual Flood for Small Catchments: Experience in Northern Ireland
Authors: Gardner C. M. K. , Wilcock D. N. 
Published: July 2007

AbstractThe paper describes six alternative equations for predicting mean annual flood from catchment characteristics, developed in and subsequent to the UK Flood Studies Report and tested for ten small catchments in Northern Ireland. The most satisfactory equation was found to be one developed in the mid‐1980s for large catchments in the Province. Equations which were developed using small‐catchment data from elsewhere in the UK performed less well. The paper considers whether there is a real difference in the behaviour of small and large catchments in Northern Ireland, and examines alternative methods of estimating the mean annual flood in partly‐urbanised areas.