bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Survey of Sheep‐Dipping Practices in the River Tweed Catchment
Authors: VIRTUE W. A. , CHURCH A. M. 
Published: July 2007

AbstractFollowing an initial exploratory survey in 1989, a detailed survey was carried out in 1990–91, the results of which indicated that a significant number of sheep dippers in the River Tweed catchment were at risk of polluting adjacent watercourses. Those dippers identified as medium to high risk of causing pollution were re‐inspected in 1992 as a follow‐up to the previous survey and, although in many cases dipping practices had greatly improved, a number were still at risk – emphasizing the importance of continued monitoring.To complement the survey, environmental samples were taken and, in most of the catchments, the dip‐active ingredients diazinon and propetamphos were found, confirming that the leaching of dip into a watercourse was occurring over a wide area throughout the Tweed catchment. The analysis of the environmental samples taken during the main dipping period each year of the survey showed that, in general, there was a significant decrease in diazinon and propetamphos in 1991 and 1992, compared to previous years.
Ozone and the Formation of Bromate in Water Treatment
Authors: BOURGINE F. P. , CHAPMAN J. I. , KERAI H. , GREEN J. G. 
Published: July 2007

AbstractThe ozonation of water is widely used within the drinking‐water industry. The improvement of the performance of the Barcombe water‐treatment works is envisaged. An ozonation stage and granular activated carbon filtration are being considered as an addition to the existing plant. As part of the investigation work, the influence of ozone on bromate formation was studied using a 3 m3/h pilot plant. The bromate production was found to depend upon (a) the applied ozone dose, (b) the contact period, and (c) the pH.Using ozone in an appropriate way will be of benefit to the treatment process as well as meeting the new World Health Organization health guidelines for drinking water.
Streambed Sediment as a Barrier to Groundwater Pollution: Insights from Fieldwork and Modelling in the River Thames Basin
Authors: YOUNGER P. L. , MACKAY R. , CONNORTON B. J. 
Published: July 2007

AbstractIntegrated fieldwork and modelling has been undertaken to assess the vulnerability of riverside wells to pollution when river water is contaminated. Results highlight the importance of streambed sediments as a barrier to groundwater pollution by river water. The bed of the River Thames is lined with brown and grey organic‐rich silts of low hydraulic conductivity (about 0.002 m/d). A 3‐D model for solute transport in stream‐aquifer systems was developed and applied to two riverside sites in the middle Thames valley. Model results indicate that well‐water quality would only breach EC limits if the river was heavily polluted for a week or even a month (clearly an unlikely scenario). Sensitivity analyses showed the models to be far more sensitive to streambed parameters than to aquifer parameters. Thus it would be more sensible to focus fieldwork on the measurement of streambed properties than on the more usually measured aquifer parameters.
An Independent Perception of Regulation in Practice
Authors: WALKER D. L. 
Published: July 2007

AbstractThe paper reviews the regulation of water companies in England and Wales since 1989 by reference to the historical regulation of utilities in these countries. It considers how comparative competition, service standards and charging arrangements are developing. Particular mention is made of the debates over rates of return and household metering. The conclusion is that regulation, to be effective and appropriate, must be capable of evolution.
Reconstruction of British Nuclear Fuel's Drigg Marine Outfall
Authors: CLARK M. W. 
Published: July 2007

ABSTRACTIn 1985 the House of Commons Environment Committee expressed reservations over some of the waste‐management procedures followed by British Nuclear Fuels Ltd at their Drigg low‐level radioactive waste disposal facility near Sellafield in Cumbria. These reservations prompted the company to implement a £20 million programme of improvements aimed at maximizing site usage, reducing trench leachate arisings and redirecting to the Irish Sea.This paper provides information and test results associated with design considerations and initial dilution testing, respectively, of a computercontrolled long sea outfall system designed to discharge leachate to the Irish Sea. Information is also provided on difficulties experienced during construction of the outfall.
Construction and Operation of a Submerged Aerated Filter Sewage‐Treatment Works
Authors: ROBINSON A. B. , BRIGNAL W. J. , SMITH A. J. 
Published: July 2007

ABSTRACTThe capacity of the sewage‐treatment works at Silchester in Hampshire has been enhanced and the effluent quality improved to a high standard by the installation of a new submerged biological aerated filter plant. Ten prefabricated steel submerged aerated filters reduce BOD and fully nitrify settled domestic sewage from a population equivalent of 20 000.Comprehensive operating data are presented to demonstrate the ability of single‐stage submerged downflow aerated biological filters to produce a nitrified effluent. The final effluent quality remains consistently within consent limits at 4.8 mg/l BOD, 7.0 mg/l SS and 0.5 mg/l NH3‐N, all 95 percentiles. (Consent 7 mg/l BOD, 25 mg/l SS, and 5 mg/l NH3‐N, 95 percentiles.)Data are presented on total coliform and E. Coli concentrations through the filter plant, showing better than 3 log reductions in the effluent.
Reconstruction of Windermere Sewage‐Treatment Works
Authors: STOCKS D. , HUNT R. , CONNOR H. , AGAR G. , CROSS R. 
Published: July 2007

ABSTRACTThis sewage‐treatment works, which is located within the Lake District National Park, on the shores of England's largest lake, receives flows from the villages of Windermere, Bowness and Troutbeck and serves a population which can double from winter to summer.The paper describes the logistical and other aspects of undertaking construction works within the confines of an existing site whilst maintaining treatment to incoming flows. The background and regulatory influences on the design of the scheme are covered, together with details of the new treatment units and the provision of facilities to strip phosphate from the effluent.
Treatment of Algal‐Laden Water: Pilot‐Plant Experiences
Authors: KAUR K. , BOTT T. R. , HEATHCOTE G. R. , KEAY G. , LEADBEATER B. S. C. 
Published: July 2007

ABSTRACTIn recent years an increase in the eutrophication of reservoirs has added to the problems of lowland surface‐water treatment. A pilot plant was installed to test the effectiveness of various treatment regimes for a river source which was subject to occasional algal blooms, and a eutrophic reservoir source which was heavily contaminated with cyanobacteria (Oscillatoria sp.). The treatment processes adopted were dissolved‐air flotation for chemical coagulation, sand and anthracite filtration, comparative disinfection stages using ozone and chlorine followed by granular activated carbon filtration.The dissolved‐air flotation plant was not particularly effective for the removal of algae, but the sand/anthracite filtration process was capable of removing 50% of the algae. The ozone disinfection stage was adequate for disinfection and also reduced algal numbers. Overall the chlorine/granular activated carbon method did not perform as effectively as the ozone/granular activated carbon process; the iatter process was +99% effective for algai control, with river and reservoir sources.
Use of Soil Maps to Predict the Incidence of Corrosion and the Need for Iron Mains Renewal
Authors: JARVIS M. G. , HEDGES M. R. 
Published: July 2007

ABSTRACTThe requirement for revised asset management plans from water‐supply companies and the need to prioritize the renewal of buried water‐supply pipework has stimulated an interest in the spatial distribution of corrosion risk and intensity. This paper reports how the relationships between soil corrosion and the spatial distribution of soil types, as displayed on soil maps, can be combined to predict the likely incidence of aggressive soils and thereby identify those water mains which are most likely to need early replacement. The concept is illustrated by a project supported by Portsmouth Water plc.
UK Drinking Water: A European Comparison
Authors: FAWELL J. K. , MILLER D. G. 
Published: July 2007

ABSTRACTIntroduction of the drinking‐water Directive has resulted in a much more quantified approach to drinking‐water quality. Increased attention from environmental groups and the media, together with occasional breaches of the limits, have resulted in a loss of confidence in the product. Infringements depend upon the stringency of the limits and the quality of available raw water. The UK is one of the few EC countries having to use a high proportion of surface water. The Directive has now been fully implemented in all member states, but information on compliance is poor. Only the UK and Ireland produce compliance reports. Published papers indicate that infringement problems exist throughout the Community, particularly for pesticides, nitrate, lead, coliforms and iron. Nevertheless, drinking water is of very high quality within the EC, and UK supplies compare very favourably with the rest.
Process Options for Phosphorus and Nitrogen Removal from Wastewater
Authors: COOPER P. , DAY M. , THOMAS V. 
Published: July 2007

ABSTRACTThe paper reviews the current capabilities of processes for phosphorus and nitrogen removal in relation to the EC urban waste water treatment Directive. The Directive is briefly described and the implications for the UK are discussed. This is followed by a review of biological and chemical processes for nutrient removal with special reference to their current state of application and performance. Particular attention is paid to processes for biological phosphorus removal which, in the past, was said to be less reliable than the chemical options but which is now being more widely applied in other parts of Europe as well as South Africa and North America. Processes for modifying both activated sludge and biological filter systems to meet the Directive are briefly described.
Integrated Catchment Management Planning
Authors: CHANDLER J. 
Published: July 2007

ABSTRACTCatchment management plans represent the National Rivers Authority's vision for the water environment. With the National Rivers Authority being organized by hydrological regions, the catchment is seen as the natural management unit, and catchment plans offer the means to integrate the Authority's work programme with those of other agencies. Catchment plans summarize relevant data and include an agreed action programme to optimize catchment uses, produced after wide consultation; they complement local authority statutory plans, are current for five to ten years, and will be reviewed regularly during this period. The catchment planning process is seen by the National Rivers Authority as a medium for promoting discussion, resolving conflict, assigning priorities, and setting targets by which progress on key issues can be monitored.
Urban Runoff: Nature, Characteristics and Control
Authors: ANDOH R. Y. G. 
Published: July 2007

ABSTRACTThe paper describes the nature and characteristics of urban runoff and the effects of urbanization and industrialization on the hydrologic/hydraulic regime and on water quality. The need for control measures to alleviate and prevent problems caused by urban runoff is highlighted, and this is related to the adverse environmental impacts of urban runoff.Measures and techniques currently available and under development for urban runoff control are described within the framework of regulators, service providers and the general public. The need for an integrated approach to urban runoff control is highlighted, and this is followed by a number of case studies demonstrating the cost‐effectiveness of an integrated approach.
Biological Processes at Saints Hill Water‐Treatment Plant, Kent
Authors: BOURGINE F. P. , GENNERY M. , CHAPMAN J. I. , KERAI H. , GREEN J. G. , RAP R. J. , ELLIS S. , GAUMARD C. 
Published: July 2007

ABSTRACTThe new treatment plant at Saint's Hill has been operating since May 1992 and biologically treats ground‐water to remove iron, ammonium/ammonia and manganese. The paper describes the project, the processes involved, the significance of pilot‐plant studies, the different stages of commissioning and plant efficiency.This method of treatment, although new to the UK, is well‐established in France, and reference to existing plants using the processes is made for purposes of indicating the range of applicability of biological treatment processes.Specific conditions are required for biological processes. Not all raw waters can be economically treated to produce an environment which is appropriate for bacterial activity. Conditions for biological iron and manganese removal are different. The paper illustrates the importance of pilot studies to establish the feasibility of biological processes and to determine the design parameters for industrial‐scale works.
Experimental Work in Continuous Monitoring of Methane in Groundwater
Authors: BRADSHAW K. 
Published: July 2007

ABSTRACTThis paper details a study to investigate the feasibility of continuously monitoring dissolved methane concentrations in groundwater. Diffusion cells have previously been used to measure methane in water but only at very shallow depths, due to the limitations of calibrations at pressures greater than atmospheric. The feasibility of using diffusion cells to determine dissolved methane at greater depths within a borehole has been established by conducting a series of laboratory experiments with a pressurized ‘bomb’. The diffusion cells have been calibrated for a range of pressures, equivalent to a depth of 90 m below water level, and dissolved methane concentrations (0–100%).Further equipment is required and a suitable site has to be identified before field trials are performed. It should then be possible to determine the concentration of dissolved methane at depth within a borehole or reservoir, by (a) installing diffusion cells, (b) monitoring the carrier gas emissions, and (c) back‐calculating the data to determine in situ concentrations of dissolved methane.
The Consent Contract for Effluent Discharges
Authors: BAYES C. D. 
Published: July 2007

ABSTRACTThe consent for the discharge of effluent is a contract between the discharger and the regulator. Its purpose is reviewed and compared with effluent performance characteristics. The evolvement of consent conditions and compliance assessment in Scotland is described, together with the challenge posed by the need to implement the urban waste water treatment Directive. A new framework for the consent contract is proposed for sewage and industrial discharges, which clearly prescribes the required effluent performance, authorizes non‐compliance, and embodies an explicit assessment of compliance.
Barrage Developments in the Welsh Region: The Role of the National Rivers Authority in Protecting the Aquatic Environment
Authors: Jones F. H. 
Published: July 2007

AbstractDuring recent years, barrages and marina developments have increasingly been viewed as a means of improving the aesthetic and recreational qualities of degraded urban areas, thereby encouraging inward investment. However, barrage schemes can have major implications for the National Rivers Authority's statutory responsibility for flood defence, fisheries, recreation, water quality and conservation.The experiences gained by the National Rivers Authority's Welsh Region in its negotiations with promoters of the Tawe, Cardiff Bay and Usk barrages are presented. The paper describes the environmental safeguards secured for the Tawe barrage, together with some initial assessments of its impact on the aquatic environment following its completion in 1992. The experience gained with the Tawe barrage has contributed to a more rigorous approach being applied by the National Rivers Authority to the Cardiff Bay and Usk schemes.
The Specification of Filtering Materials for Rapid‐Gravity Filtration
Authors: STEVENSON D. G. 
Published: July 2007

ABSTRACTA UK standard for the specification, approval and testing of filtering materials has recently been published by British Water (formed by the merger of the British Effluent and Water Association and the British Water Industries Group) in response to an identified need. This paper reviews the considerations during the preparation of the standard and provides a technical background. The approach has been to base the standard on parameters which affect the behaviour of the material during filtration, rather than to specify material composition and appearance, which are unimportant. Standards and specifications are a basis for testing, and the inclusion of irrelevant parameters can lead to unnecessary work.
The Application of Risk Assessment to Contaminated Land: The British Gas Experience
Authors: WALKER P. L. , MUNRO S. , HAWKINGS C. L. , SHEPHERD F. E. 
Published: July 2007

ABSTRACTBritish Gas owns over 900 sites within the UK with a total land area in excess of 5500 ha. Many of the sites are former gasworks, chemical works or associated holder stations.Although serious attempts were made to remove contamination during the last three decades, the operating and demolition standards previously considered to be adequate may no longer be acceptable and may have given rise to sites with the potential to contaminate adjacent land, surface waters and ground‐water. As a result, further actions may now be required on these sites to reach new environmental standards, thereby reducing any chance there may be of legal liability on the Company.This paper describes the advantages and disadvantages of several qualitative and quantitative risk‐assessment methods which can be used to prioritize potentially contaminated sites for further investigation. The use of site investigation data to accurately target risk reduction in site remediation proposals is also discussed.
Integrated Catchment Modelling as a Water Resources Management Tool
Authors: RIPPON P. W. , WYNESS A. J. 
Published: July 2007

ABSTRACTGroundwater models are becoming increasingly important in water resources management. Most aquifers in the UK are closely linked with river systems, to which they contribute baseflow from seepages and springs. As a result, major groundwater abstractions almost inevitably affect river flows. To assess with confidence the effect of utilizing ground‐water resources, an aquifer and river system has to be linked within an integrated model which can simulate varying hydrogeological conditions throughout the catchment.The main features of an integrated catchment management model, which links aquifer and river systems, are described in this paper. The model has been applied to a number of catchments in southern England including the River Darent in Kent, which is probably the most well‐known and worst‐affected of all rivers identified nationally as suffering from over‐abstraction.The process of model preparation and calibration is illustrated with reference to the River Darent. Twenty years of river flow and groundwater hydrograph records were used in producing a close simulation of modelled and actual hydrological conditions. The model was then operated to assess a large number of possible options for restoring flows to the river. Examples of various management strategy simulations are given, leading to formulation of a water resources management plan for the Darent. This involved (a) reductions in selected abstractions, (b) flow augmentation using river support boreholes, and (c) meeting peak groundwater supply demands in drought periods.
Real‐Time Water Allocation for Irrigation
Authors: HANNAN T. C. , COALS V. A. 
Published: July 2007

ABSTRACTThroughout the world the importance of water management is becoming more important as the demand for water increases. As one of the major uses of water, irrigation could benefit from improved management practices. The establishment of a Water Operations Centre in Indonesia has seen the development of a real‐time water‐allocation model for a complex irrigation system covering 60 000 ha. The model uses linear programming (an optimization technique) to determine the best way in which to allocate limited water supplies while keeping crop yield losses to a minimum.
North Tyneside Bathing Waters’ Scheme
Authors: FRITH S. J. , STAPLES K. D. 
Published: July 2007

ABSTRACTThe North Tyneside bathing waters’ scheme reduces the frequency and quality of storm sewage which is discharged inshore from existing interceptor sewers along the coast.Flow‐simulation modelling is applied to the existing system to determine the frequency and volume of interceptor sewer overflow against a range of storm intensity and return periods. The models are extended to an evaluation of new systems of storm‐sewage management.An optimized solution is described in which new storm sewers are utilized for the storage of all storm‐sewage overflow discharges prior to screening and pumping of the storm sewage to sea via an outfall.
Pesticide Transport to Surface Waters within an Agricultural Catchment
Authors: WILLIAMS R. J. , BROOKE D. N. , MATTHIESSEN P. , MILLS M. , TURNBULL A. , HARRISON R. M. 
Published: July 2007

ABSTRACTThis paper presents data on the distribution of seven pesticides in an agricultural catchment which is located within the Agricultural Development and Advisory Service farm at Rosemaund, 11 km north‐east of Hereford, UK. Data for aldicarb, atrazine, carbofuran, dimethoate, MCPA and isoproturon, are available for both the soil and surface waters (drain and stream water), with simazine data available only for the stream. Measurements were taken before and after pesticide application, which was made following normal agricultural practice. Soil residue data showed the degradation rates of the pesticides to be within the range of literature values. Pesticide levels in the stream and drains during runoff events following rainfall ranged from below detection limits (typically 0.02‐0.1 μg/1), to 264 μg/1 (for carbofuran). Over 90% of the events had detectable maximum concentrations. The percentage of pesticide applied, which was removed during individual rainfall events, was calculated. The maximum value estimated was 1.1%, again for carbofuran. Most of the events gave values several orders of magnitude below this value.The data have been used to try to validate a range of models which could be used for screening new pesticides or for informing decisions on the use of existing pesticides. The results of the validations are summarized.
Upgrading the Activated‐Sludge Process for Total Nitrogen Removal in Hong Kong
Authors: WU D. K. C. , LAI H. C. , LAW K. W. , WONG W. C. 
Published: July 2007

ABSTRACTIn order to protect the sensitive waters in Tolo harbour (Hong Kong), Sha Tin and Tai Po sewage‐treatment works were first designed to remove 70% of the nitrogen load from the sewage. Since then, due to continuing serious eutrophication problems in the harbour, both plants have been modified to increase the removal efficiency to 90%.The modifications were based on the Bardenpho process. However, the designers of the two plants adopted different approaches to process intensity, complexity and control of bacterial foam. At Sha Tin, the average monthly results have shown an increase of total nitrogen removal from 60–70% to about 80% since its completion. The addition of methanol was found to be ineffective on further enhancement of the denitrification rate due to difficulties in the apportioning of the second anoxic zone. The overall monthly results for Tai Po have also shown an increase in the removal rate to about 80%, even though 90% was achieved for a short period of time. The major problem encountered at the latter plant was that the process design did not provide an effective control on bacterial foaming, which had affected the smooth operation of the process.