bluuebunny/crossref_metadata_2025 huggingface dataset:
PREDICTIVE MODELING APPLIED TO GROWTH OF SPOILAGE VIRGIBACILLUS PANTOTHENTICUS ON INDUSTRIAL CRÈME CARAMEL
Authors: GONZÁLEZ RUBEN DARIO , HUNZICKER GRETHEL MARA , DE SOUSA GLADYS BEATRIZ , TAMAGNINI LUCIA MARÍA , BUDDE CARLOS ERNESTO
Published: July 2007

The aim of this work was to identify the spoilage microorganisms in commercially produced crème caramel and to study their growth kinetic in different conservation conditions. Fifty‐four randomly selected strains were isolated from altered crème caramel samples with typical “medicine smell.” In order to detect the strains that cause the smell alterations, an experimental medium (PM) was prepared with crème caramel. Nineteen out of 28 isolated strains of gram‐positive spore‐former bacteria developed “medicine smell” in PM medium. Of the 19 isolated strains, five were identified as Virgibacillus pantothenticus. One was studied in a fermenter in aerobiosis at 4, 12 and 30C and in anaerobiosis at 30C. The modified Gompertz model was applied. In aerobic conditions, the maximum growth rate decreased with the temperature: μ = 1.68 at 30C and μ = 0.28 at 12C; at 4C, there was neither growth nor alteration. In anaerobic conditions, at 30C the maximum growth rate was lower than in aerobiosis (μ = 0.90), and there was no smell alteration. The appearance of these alterations was independent of the maximum growth rate. “Medicine smell” was a result of piperonal alterations. Microbiological spoilage risk could be reduced with tight control of the temperature in the production chain.
Groundwater Investigations in the Lower Spey Valley, near Fochabers
Authors: WATT G. D. , MELLANBY J. F. , van WONDEREN J. J. , BURLEY M. J.
Published: July 2007

SYNOPSIS

A Series of: comprehensive studies have been carried out to identify potential water abstraction sources to meet future demands throughout the Grampian area, in Scotland. In the Moray and Banff coastal areas a new supply is to be developed to meet future increases in demand which have been predicted to be about 9 MVd by the year 2001, increasing to about 18.5 Ml/d by the year 2011.

Grampian Regional Council has engaged Sir M. MacDonald & Partners, consulting engineers, to examine various options within the area and the consultant has concluded that the development of the alluvial gravels on the west bank of the river Spey immediately upstream of Fochabers would provide the Council with the best solution.

The paper describes the various investigations undertaken. The main conclusions and results of the studies are briefly outlined in the following paragraphs.

The alluvium was shown to have good water‐transmitting properties. The seismic refraction and borehole investigations confirmed the superficial deposits to be about 10 to 15 m. Test pumping of wells with associated piezometers proved the transmissivity values and storage coefficients of the aquifer and hence a suitable wellfield.

The wellfield so identified extends some 2.8 km upstream on the west bank from the bridge across the river Spey at Fochabers, with an estimated reliable yield of 20 MVd. The water abstracted from the test wells was shown to be about 80 per cent river water which had been drawn into the aquifer. The contribution from the landward side could result in a reduction of the watertable affecting the yield of deep rooted crops (cereals and grass) over about one‐half the area one year in three.

Examination of the water drawn from the wells confirmed it to be low in colour, iron, and manganese. The results were consistent and were of drinking quality. The mechanism causing the dramatic change in the water from river to well was thoroughly explored and found to be a biological process so ensuring that water qualities would be sustained.

In conclusion, the various studies undertaken have shown that a consistent high quality water can be produced from the alluvial gravels of the river Spey near Fochabers in sufficient quantity to meet the needs of the lower Moray and Banff coastal areas of Grampian Region to the year 2011.
The SERC Flood Channel Facility
Authors: KNIGHT D. W. , SELLIN R. H. J.
Published: July 2007

SYNOPSIS

The Paper describes a new large central experimental facility which has recently been built to investigate the hydraulic behaviour of rivers and flood alleviation channels when they flow in an out‐of‐bank condition. The SERC flood channel facility is jointly funded by the Science and Engineering Research Council (SERC) and Hydraulics Research Ltd (HR), on whose premises the facility has been built.

A five‐year research programme has been identified and will be supported by the SERC together with a contribution from the Ministry of Agriculture, Fisheries and Food (MAFF). The authors outline the need for such a facility in flood channel research, the background to the design, construction and instrumentation of the facility, and give brief details of the initial phase of the research programme, which involves four university research teams.

It is hoped that the SERC flood channel facility will be a focus for other experimental researchers and will bring together theoreticians, numerical modellers and experimentalists concerned with river channel hydraulics. At present seven UK universities are involved in the SERC Working Party on Flood Channels, along with representatives from HR, MAFF and consultants.
Investigation of Petroleum Refinery Effluent Treatment in an Aerobic Fixed‐film Biological System
Authors: HAMODA M. F. , AL‐HADDAD A. A.
Published: July 2007

SYNOPSIS

The feasibility of treating a synthetic toxic waste and a petroleum refinery effluent was evaluated using a four‐stage, fixed‐film aerated bioreactor with a 50 I capacity and a surface area‐to‐volume ratio of 72. The process performance at various waste strengths and influent flow rates was found satisfactory.

Organic loading proved to be a better operational or design parameter. Treatment efficiency decreased as the loading was increased. An organic loading of 42 g COD/m2d or less is recommended to ensure good quality effluent. The reactor coped with organic and hydraulic overloads because of the good oxygen transfer capacity and the considerable quantity of attached biomass attained. Staging of the reactor was effective in damping excessive loadings.

Treatment of the refinery waste in the bioreactor removed up to 80 per cent of the COD and reduced the oil, sulphide and amm.N concentrations substantially, but polishing of reactor effluent using alum treatment improved effluent quality for potential reuse.
Groundwater Model of Conditions in Liverpool Sandstone Aquifer
Authors: RUSHTON K. R. , KAWECKI M. W. , BRASSINGTON F. C.
Published: July 2007

SYNOPSIS

This study considers the groundwater conditions for the period 1948–82 in the Permo‐Triassic Sandstone aquifer of the Liverpool area. During this period, significant changes have occurred in the abstraction patterns and a new railway tunnel has been constructed below sea level in Central Liverpool. To understand the flow conditions within the aquifer, detailed studies have been carried out into the aquifer properties, the influence of rivers and tunnels, and the estimation of recharge. It is found that conventional rainfall recharge accounts for only one‐third of the total recharge.

Numerical model solutions were used to check the adequacy of the understanding of the flow processes and the solutions have confirmed that the rising water levels in Central Liverpool result from high recharge and a reduction in abstraction. Having validated the model by comparisons with field data, the model was then used to predict the probable future water level changes.
Groundwater Quality Beneath the City of London ‐ Overview and Long‐term Changes
Authors: PAYNE JUDY A. , THOMAS W. M. , COOKE J. E. , ENGLISH E.
Published: July 2007

The quality of groundwater from the chalk beneath the City of London is discussed in relation to the geology and overpumping of the aquifer in the nineteenth and early twentieth centuries. The current quality of the water is describd with reference to analyses carried out, and reasons for variation in quality between boreholes are suggested. Current quality is compared with that of 50 years ago, revealing major changes in the chemical characteristics of the water which are explained in terms of changing groundwater levels.
The Application of Bacteriophage Tracer Techniques in South West Water
Authors: Martin C.
Published: July 2007

The Application of bacteriophages as tracers in various aquatic systems is described with examples of three specific applications in the South West Water Authority area.

The first two examples illustrate the use of bacteriophage for leak detection of a sewer and an impounding dam. The third example compares bacteriophage with fluorescein for the determination of time of travel in a river.
Water Recreation and Risk
Authors: LACEY R. F. , PIKE E. B.
Published: July 2007

This paper deals with concepts and methods that may be used in the assessment and management of risks associated with aquatic recreation. It aims to explore potential approaches and to indicate their strengths and weaknesses. The paper concentrates on hazards encountered in bathing, swimming and water‐contact sports that may be affected by water quality. Aspects discussed include: the role of society in regulating risks that are taken voluntarily by individuals; the difficulties of measuring those risks by means of epidemiological studies; the questionable predictive power of bacterial indicators and the problem of finding a satisfactory rationale for determining the standards for recreational waters.
Groundwater Pollution and the Disposal of Hazardous and Radioactive Wastes
Authors: MATHER J. D.
Published: July 2007

The demand for‘Rolls‐Royce’ solutions to the disposal of hazardous and radioactive wastes has seen a continuing move towards more sophisticated disposal concepts. If a disposal site for radioactive wastes meets the strict requirements laid down by Government departments it is difficult to see why there should be any impact to groundwater of concern to the water industry. Hazardous wastes are a much more significant problem, and the large size of many landfills, other pressures on groundwater quality and current EC directives are all contributing to a move away from the use of ‘dilute and disperse’ sites. It is argued that the long‐term performance of containment sites needs to be carefully evaluated over timescales of 2‐3 decades, as over such periods a correctly‐managed policy of ‘dilute and disperse’ may result in less of an overall impact to the environment than a policy of ‘concentrate and contain’.
Operating Experiences at Langsett Water Treatment Works
Authors: BRIENS P. J. , LYON D. K. , BAGGALEY R.
Published: July 2007

The new treatment works at Langsett, in the Pennine foothills of South Yorkshire, was commissioned by Yorkshire Water in July 1985. The works represented a fresh approach to the treatment of highly‐coloured upland Pennine waters utilizing a chemical process.

This paper describes the treatment process and reviews the experience which was gained during the first two years of operation. The process has occasionally suffered due to failure of the supporting equipment, and some important lessons have been learned. Subsequent modifications to the treatment plant and method of operation are described.
Instrumentation, Control and Automation: the Grampian Way
Authors: GORDON A. L.
Published: July 2007

The paper describes the experiences of Grampian Regional Council's Department of Water Services in designing, testing, and installing a regional telemetry system, together with the philosophy behind some of the decisions. The paper also describes the hardware involved and some of its capabilities.
Screening at Marine Outfall Headworks
Authors: THOMAS D. K. , BROWN S. J. , HARRINGTON D. W.
Published: July 2007

The UK approach to pollution control in tidal waters places considerable emphasis on balancing the contrasting needs of utilization of the waters for the assimilation of effluents with the protection of all identified uses, i.e. the Environmental Quality Objective/Environmental Quality Standard (EQO/EQS) approach. In order to protect uses of the waters for bathing and general amenity, this approach in the design of improvement schemes necessary for marine sewage discharges is examined. However, recent guidelines for consent applications dealing with schemes designed to protect bathing use suggest a departure from the EQO/EQS approach towards an emission standard when dealing with the solid phase of the sewage effluent. The implications of these approaches are discussed from the design (scientific and engineering) viewpoints.

A summary of headworks processes and the current practice for preliminary treatment at marine outfall sites in the UK is reviewed, together with comments on their effectiveness. The terms of reference and work of a joint working group to examine the efficiency of screening equipment at marine outfall headworks is described, together with a technical summary of results collected at a range of sites and with various types of equipment. Recommendations for future research are given, and a strategy for screening is developed.
The Application of Remote Sensing to Estimate Land Cover for Urban Drainage Catchment Modelling
Authors: FINCH J. , REID A. , ROBERTS G.
Published: July 2007

This paper compares the estimates of percentage land cover derived from airborne thematic mapper data with those from a traditional survey method. The latter include existing Ordnance Survey maps and an on‐the‐ground survey supplemented by aerial photographs. The thematic mapper data are segmented using two methods: thresholding and classification. Nine catchments are surveyed using the three methods. The different results are discussed, and their implications for the calculation of surface runoff are investigated. Estimates of the relative costs in the traditional and remote‐sensing methods are compared, simulated satellite images of the study are analysed, and the potential use of satellite data in this application is discussed.
Operating Experiences of Full‐Scale Biological and Ion‐Exchange Denitrification Plants in France
Authors: RICHARD Y. R.
Published: July 2007

In France, nitrate removal by biological means was authorized in 1981 and by ion exchange in 1985. To date, four installations use the biological process and six plants incorporate ion‐exchange techniques. Details of the plant are explained. The first conclusions can now be drawn from the results of the startup period as well as from operation. The existing facilities produce water in compliance with laid‐down regulations, and in a reliable manner throughout the year. The average capital costs of all the French facilities are given, together with typical operational costs.
Use of Mixing Zone to Derive a Toxicity Test Consent Condition
Authors: HAIG A. J. N. , CURRAN J. C. , REDSHAW C. J. , KERR R.
Published: July 2007

This paper describes how the Clyde River Purification Board (the regulatory authority) and Bee‐cham Pharmaceuticals (the identified discharger) agreed and adopted a novel means of controlling a pharmaceutical plant effluent which is discharged to Irvine Bay, Scotland. Control was achieved by means of a consent (licence) condition requiring compliance with a laboratory test of acute toxicity, which was added to the more orthodox conditions already imposed upon the discharge. The new condition was derived using the concept, explicit in the environmental quality objective/environmental quality standard approach to pollution control, of an allowable mixing zone around the outfall. The derivation and validation of the condition necessitated laboratory and field bioassay, current measurements and dye releases, and the use of a plume development model.
The White Cart Water Flood Alleviation Study using Hydrodynamic Mathematical‐Modelling Techniques
Authors: BANKS D. J. , FALCONER R. H.
Published: July 2007

This paper describes a hydrodynamic mathematical‐modelling study to investigate the flooding problem and to recommend various flood‐alleviation measures for the White Cart Water on the southern side of Glasgow. The mathematical model covers 36 km of the White Cart to the tidal reaches at the confluence with the River Clyde, and includes 7 km of one of the major tributaries where regular flooding is also a problem. A key aspect of the study was the close proximity of the modelling team which permitted a close scrutiny of the river during high‐flow events. From these observations the team obtained a thorough appreciation of river behaviour during potential flood situations, which provided a reliable and comprehensive set of data for model calibration over a wide range of conditions. The proposals for flood alleviation have far‐reaching implications and require major capital expenditure. At present they are being examined by Strathclyde Regional Council in consultation with the many interested parties.
The Pollution Aspects of Storm‐Sewage Overflows
Authors: BALMFORTH D. J.
Published: July 2007

Storm‐sewage overflows are one of the principal sources of urban river pollution in the UK. The paper (a) outlines the various possible pollutants and their effect on the receiving stream, and (b) identifies the features of individual overflow structures which are likely to lead to unsatisfactory performance. Since the rationalization and rehabilitation of storm‐sewage overflows should only be considered as part of a more general drainage area study, a strategy for rationalization is presented which identifies objectives for effective design and operation; it discusses, in particular, how chambers may be proportioned to give effective separation of visible pollutants. By combining field data with the results of model tests, a comparison of the performance of the main recommended types of overflow structure is given, together with a discussion of maintenance and safety aspects.
The Application of Water‐Quality Standards to UK Bathing Waters
Authors: KAY D. , WYER M. , McDONALD A. , WOODS N.
Published: July 2007

Data for 425 sampling locations in England and Wales, covering the 1987 bathing season, were analysed against a range of six water‐quality standards used by European and North American agencies. The following order of relative stringency was established: EEC guide level > US Environmental Protection Agency† > Toronto†> Canadian Federal† > Modified EEC standard > EEC imperative level†.

All European Community (EC) countries, at present abiding by the‘imperative’bacteriological standards of the bathing waters Directive, would experience a significant increase in non‐compliance for the faecal coliform parameter if standards were altered from the current EEC imperative criteria to any of the existing alternative beach management standards.
The Chadwick Centenary Lecture ‐ A Review of Two Centuries of Public Health
Authors: ACHESON M. A.
Published: July 2007

Sir Edwin Chadwick, who has been recognized as the father of British sanitary science, died in 1890. This lecture commemorates the centenary of his death. It describes the appalling sanitary conditions existing in the early nineteenth century, traces the achievements made during the life of Chadwick, and reviews the influence these have had on the development of public‐health engineering in the UK and internationally in the nineteenth and twentieth centuries. The lecture concludes with some reflections on contemporary issues related to environmental health and the future role of the environmental engineer.
Occupational Risks from Infectious Diseases in the Water Industry
Authors: WEST P. A. , LOCKE R.
Published: July 2007

Workers in the water industry are sometimes exposed to infectious micro‐organisms, particularly during the treatment and disposal of sewage. There is a legal requirement for water companies to appraise the degree of risk to which employees are exposed and then take appropriate action to minimize such risks. This is accomplished, to a large extent, by first understanding how infectious diseases are spread, and then devising safety practices to minimize occupational exposure to pathogenic micro‐organisms. Examples are given of types of communicable disease potentially associated with drinking water treatment (Legionnaires' disease and leptospirosis), as well as sewage treatment (viral gastroenteritis, AIDS and hepatitis B). The degree of perceived occupational risk associated with these pathogenic micro‐organisms is discussed along with preventative measures that can be implemented to minimize actual risk. There is no justification for enhanced immunization of water industry employees.
Automatic Coagulation Control at Water‐Treatment Plants in the North‐West Region of England
Authors: CRITCHLEY R. F. , SMITH E. O. , PETTIT P.
Published: July 2007

North West Water has evaluated several automatic coagulation control systems covering a range of raw waters and treatment facilities.

The experiences have shown that streaming‐current type systems are effective in controlling coagulant dose automatically, provided that appropriate plant conditions exist. In particular, rapid fluctuations in flow or poor mixing of chemicals can lead to unstable signals. Recent investigations indicate that for some waters streaming‐current voltage is sensitive to small changes in pH, and precise control of pH is therefore necessary.

The main observed benefits have been treated water of a more consistent high quality, together with improved security of service, as the systems will respond reliably and effectively over long periods. Significant savings in coagulant usage can be obtained in certain cases.
Particulate Lead in Water Supplies
Authors: HULSMANN ADRIANA D.
Published: July 2007

This paper describes research in areas where the occasional failure to meet the EC standard for lead in drinking water is due to the presence of particulate lead. A method is described to disinguish between soluble, particulate and colloidal lead in tap water, and characteristics are given of water sources which are most likely to suffer from this form of lead problem. At least two types of particulate (insoluble) lead in tap water have been identified, and some factors are discussed which cause the occurrence of both types. Interim results of trials are presented, with remedial actions.
Performance of Fabric‐Protected Slow Sand Filters Treating a Lowland Surface Water
Authors: MBWETTE T. S. A. , STEITIEH M. A. R. , GRAHAM N. J. D.
Published: July 2007

The performance of slow sand nitration can be; substantially improved by the application of a non‐woven synthetic fabric layer to the surface of the sand. By means of pilot‐scale experiments, using the i River Thames as the source water and pretreatment by sludge blanket clarifiers, the comparative performance of fabric‐protected slow sand filters has been evaluated over an eight‐month period. Under conditions designed to simulate poorly‐controlled pretreatment, a correctly‐specified fabric type, configuration and thickness can extend filter run times by a factor of 3–5 compared to a conventional slow sand filter. Furthermore, this can be achieved, together with the avoidance of any significant change in the hydraulic behaviour of the underlying sand, thereby avoiding the need to remove and clean sand. Fabric washing is relatively simple and efficient.
Rivmer Basin Management: Developing the Tools
Authors: FIDDES D. , CLIFFORDE I. T.
Published: July 2007

A coordinated research and implementation programme (the River Basin Management programme) involving a number of funding organizations is described, which sets out to bridge the gap between academic research and practical application of the findings in upgrading sewerage systems. The key to success is seen to be involving the end user as soon as possible in field trials, to assist the researchers in proving and enhancing the methodology. Using these tools, an integrated approach to receiving‐water quality standards achievement is possible, which is seen to give substantial environmental benefits and capital cost savings when compared to the rigid application of best available technology.
Trenchless Technology
Authors: FLAXMAN E. W.
Published: July 2007

This paper outlines some of the technical developments which have given rise to the rapid advance in trenchless construction. The paper then discusses some of the other factors ‐ political, administrative, and legal ‐ which affect the adoption of the new technology.
Abbeystead Outfall Works: Background to Repairs and Modifications – and Lessons Learned
Authors: ORR W. E. , WOOD SIR ALAN MUIR , BEAVER J. L. , IRELAND R. J. , BEAGLEY D. P.
Published: July 2007

The explosion at the Abbeystead valve house in May 1984, with its attendant loss of life and injury, forcibly drew the attention of the public to the dangers of methane and other natural gases. It also reaffirmed to the water industry and engineering professions the pervasive nature of the gas and the need to take appropriate measures in the construction, design and operation of any scheme which involves a possible methane presence. The investigations into the source and mechanism of the methane gas ingress, and the design of the permanent repairs and modifications to the scheme, have illustrated many of the risks and problems associated with methane and the measures for dealing with them.

The paper describes the essential repairs and modifications which had to be carried out, the main lessons learned, and the recommendations which are felt to be applicable to new and existing water schemes where methane may be present.
Liquid Effluents: New Solutions to Old Problems
Authors: PhD E. K. MACDONALD
Published: July 2007

Effluent discharges from industrial processes will come under increasingly close scrutiny in the future, as legislation reduces the limits for discharges. Existing processes will, in many cases, be unable to meet the more stringent controls. Therefore a new generation of processes, capable of removing chemical pollutants from waste streams to nanogram levels, needs to be developed. Already the nuclear industry has extensive experience of applying some of these emerging technologies to control radioactive discharges, and is developing these processes further through the collaborative forum of AEA Technology's Effluent Processing Club so that they may be economically applied in the non‐nuclear process and manufacturing industries.
Fenay Beck Flood‐Alleviation Scheme
Authors: WINDERS J. D.
Published: July 2007

The paper describes flood detention and channel improvement schemes which have been designed to alleviate the flooding of domestic and industrial properties to a 50‐year standard of protection. Landscape architects were incorporated into the design teams to cover environmental aspects.

The flood‐detention dam would have been constructed mainly of colliery waste, and the design of the concrete horseshoe spillway and stilling basin was checked using a 1 : 40 physical model. River regulation would be by an automatic vertical gate activated by downstream water levels.

Following planning refusal, a channel‐improvement scheme was adopted, which is presently under construction. Reduction in valley storage increased downstream flows, necessitating the enlargement of an old brick and concrete culvert within the ICI works to ensure that there were no detrimental effects within their boundary. An increased benefit/cost ratio of 3.46, as compared with 2.55 obtained for the detention scheme, was partly due to the application of new standards.
Reservoir Storage/Yield Analysis Using the Annual Failure Method
Authors: BROWN R. P. C.
Published: July 2007

The ‘annual failure method’is presented as a new method for estimating the relationship between reservoir storage, yield, and frequency of failure. It is based on ‘semi‐infinite storage analysis’to determine critical storage volumes from the flow record for the given yield. ‘Behaviour analysis’performed on these storages allows estimation of the frequency of annual failure by counting the number of years in which a storage volume is exceeded. The method has been developed using data from flow records in northern and western Europe.
Mechanisms of Groundwater Pollution by Pesticides
Authors: FOSTER S. S. D. , CHILTON P. J. , STUART MARIANNE E.
Published: July 2007

An increasing number of pesticide compounds are being detected in groundwater supplies worldwide. There has, nevertheless, been little research into the mechanisms by which such pollution occurs and the routes via which pesticides move from the land surface into aquifers. In view of the potential time‐lag in the response of groundwater systems to pollution inputs, such knowledge is essential if the current situation is to be appraised adequately and if any necessary controls on pesticide use are to be introduced.

From basic data on the physicochemical properties of pesticide compounds and on groundwater flow and pollutant transport in the principal British aquifers, some useful observations can be made about the relative significance of different mechanisms of potential groundwater pollution. These mechanisms and their implications for field research on pesticide pollution of groundwater are discussed. This problem is compared and contrasted to that of nitrate pollution from agricultural land‐use practices.
Environmental Impact Assessment and the Water Industry: Implications for Nature Conservation
Authors: BOON P. J.
Published: July 2007

The Nature Conservancy Council has welcomed the implementation of the EC Directive on the assessment of the effects of certain projects on the environment. This paper discusses its implications for nature conservation in fresh waters, particularly with reference to the land‐drainage and flood‐defence work carried out by the National Rivers Authority and its predecessors, to which the regulations SI 1217 apply. Environmental statements have been deemed necessary for only a small proportion of capital schemes initiated by the water industry since the Regulations came into force in 1988. The author has evaluated the nature‐conservation content of 15 of these statements against a combined set of objective and subjective criteria. The statements examined showed a high degree of variability in length, scope, style and presentation. In general, survey and data acquisition were poorly covered. The weakest area was considered to be the evaluation and prediction of potential impacts, and this is discussed in relation to the uncertainty and complexity inherent in biological systems. The need for monitoring the accuracy of predictions after the completion of a scheme received little attention, despite its fundamental importance in improving future project design, and in extending scientific understanding.
Design and Construction Quality Assurance
Authors: CLAPHAM G. S.
Published: July 2007

The paper describes the development, introduction and operation of quality assurance, with specific application to the design and construction industry and the consequential benefits which can be derived from the adoption of formalized quality assurance supported by third‐party certification.

The main objectives of formalized third‐party quality‐assurance certification are in respect of: (i) quality‐management systems of firms who provide a service to the industry and who meet the requirements of BS 57501, EN 290002, ISO 90003; and (ii) product conformity to firms who show compliance with a national or other approved specification and who operate a BS5750 quality‐management system.
The Procurement and Testing of Process Plant for the Water Industry
Authors: CLAPHAM G. S. , LOWE P.
Published: July 2007

The paper describes contractual procedures necessary when performance guarantees are required for process plant. It shows how the Institution of Chemical Engineers Model Form of Conditions of Contract for Process Plants (Red Book) can be suitably modified to meet the needs of the water industry.

Particular attention is given to devising suitable testing regimes to meet the contract stages – construction, completion, take‐over, and performance tests. The principles underlying the proposed testing procedures are stated.
Design and Construction of an Ion‐Exchange Denitrification Plant in South Staffordshire
Authors: FLETCHER I. J. , Woodward A. J. , HENWOOD N. G.
Published: July 2007

Increasing concern about rising levels of nitrate in groundwater supplies and their subsequent removal to comply with EC drinking water standards has led to the construction of the first full‐scale ion‐exchange nitrate‐removal plant in the UK by the South Staffordshire Waterworks Company.

This paper describes the development of the project from concept, through pilot‐plant studies to final design, installation and commissioning. It explains the role of ion‐exchange technologies, the use of recently developed nitrate‐selective resins and the development of a novel dual regeneration system. The initial performance of the full‐scale plant is discussed.
Ultra‐Violet Disinfection of Sewage Effluents: A Pilot Study at Bellozanne, Jersey
Authors: GROSS T. S. C. , DAVIS M. K.
Published: July 2007

In March 1990 a pilot ultra‐violet disinfection plant was installed at the sewage‐treatment works in Bellozanne, Jersey. The pilot plant was set up to test the ability of the process to meet certain defined objectives and, ultimately, to enable the island authorities to satisfy stringent water quality objectives in the receiving waters of St Aubins Bay.

The pilot study simulated an open channel installation using medium pressure ultra‐violet lamps parallel to the direction of flow. The pilot plant was supplied by Trojan Technologies Inc.

The pilot study met its objectives and confirmed the design parameters for a full‐scale plant installation to follow.
Measurements of Head Variations within Observation Boreholes and their Implications for Groundwater Monitoring
Authors: BRASSINGTON F. C.
Published: July 2007

As part of several groundwater investigations of the Permo‐Triassic Sandstone aquifers in north west England, a detailed measurement of piezometric heads and groundwater flow within observation boreholes was made which showed that vertical differences of groundwater heads persist within aquifers. A number of case histories of these studies are presented, which are used to consider the impact of head variations on typical groundwater level and groundwater quality measurements taken in observation boreholes, with a view to recommending design criteria for observation boreholes and groundwater monitoring programmes.
Examples of Recent Models in Environmental Impact Assessment
Authors: WHITEHEAD P.
Published: July 2007

Models are being used extensively to study the impact on the environment of a wide range of man‐made influences. These include land‐use change (e.g. afforestation), effluent discharges, flood‐relief channels, reservoir developments, atmospheric pollution and the impacts of agrochemicals. In this paper several models are described which are being used by the Institute of Hydrology for environmental impact assessment. These models include MAGIC (Model of Acidification of Groundwater in Catchments), QUASAR (Quality Simulation Along Rivers) and a nitrogen simulation model for investigating the behaviour of nitrate in reservoirs.
Paying for Water: Policy Options and their Practical Implications
Authors: THACKRAY J. E.
Published: July 2007

Paying for water supply, wastewater and surface water sewerage and treatment, and river basin management, is considered against the four strategic options of using taxation, charges to users, accepting environmental damage, and charitable funding. The different social consequences of each are addressed. A fundamental appraisal of issues of cost analysis is provided, and often overlooked factors are identified. The merits of (a) alternative tariff forms including rising and falling blocks, (b) seasonal and time‐of‐day tariffs, and (c) cover/fixed charge approaches are analysed, together with the often more cost‐effective use of tariffs without meters for households. The important role of the engineering elasticity of demand is set alongside the more often discussed concept of economic elasticity.
Japanese Sewage Sludge Treatment, Utilization and Disposal – Report on IWEM/JSWA Technology Exchange Programme, November 1991
Authors: TEBBUTT T. H. Y.
Published: July 2007

The report describes visits made as part of a mission to Japan which included, under the IWEM/JSWA Technology Exchange Programme, a Technical Workshop on sewage sludge technology held in Tokyo on 11–18 November 1991.
Asset Appraisal of Trunk Mains
Authors: AIKMAN D. I.
Published: July 2007

Over the past decade, much attention has been paid to the assessment of water distribution networks. Attention now is turning towards the larger diameter trunk mains. The increased scale and cost of investigative work means that a change of approach is needed and, in some cases, new investigative techniques.

This paper discusses the general approach to the appraisal of trunk mains (and aqueducts) and, based on practical experience, considers solutions to a number of problems associated with inspection work.

A case study is presented, based upon a preliminary appraisal of the Vyrnwy Aqueduct, which was carried out in 1988–89. The aqueduct was first commissioned in 1891, and now contains some 325 km of large diameter pipes, in both cast iron and steel.
Financial and Economic Measurement of Environmental Factors
Authors: B. BODDINGTON M. A.
Published: July 2007

The paper describes how financial and economic aspects can be analysed and quantified in environmental assessment, and how this can be related to the losses or gains in any given project. Projects which require environmental assessment often have the image of being harmful to the environment ‐ as is the case of new roads, railways or developments which either take land out of agriculture or attract an environmentally damaging image. Many projects involve resources which are not traded and which are not always valued in financial or economic terms. Nonetheless, they are capable of being valued in this way, and their evaluation leads to greater understanding in decision‐making. The study, undertaken to assess the costs and benefits of drainage for the middle and south level barrier banks on the Ouse Washes, demonstrates how (a) financial and economic analysis of the cost, and (b) the gains of a project, can guide the allocation of public resources to the benefit of the environment.
The Effect of Leakage Control and Domestic Metering on Water Consumption in the Isle of Wight
Authors: DOVEY W. J. , ROGERS D. V.
Published: July 2007

The paper presents a brief background to the national metering trial on the Isle of Wight, for which installation was completed in early 1991. Various aspects of the meter installation policy are relevant in terms of their effect on leakage. The main part of the paper describes some early indications of the impact of domestic metering on leakage and consumption in the Isle of Wight Division of Southern Water Services Ltd.
Environmental Management of Landfill Sites
Authors: V. CAMPBELL D. J.
Published: July 2007

The paper reviews various options adopted in the UK for engineered protection measures aimed at preventing pollution to the environs of landfill sites. The advantages and limitations of both natural and synthetic lining materials are discussed, recognizing the constraints posed by the geometry and geology of prospective landfill sites. Particular attention is given to the Environmental Safety Centre experience with techniques designed to minimize both leachate and gaseous emissions, and hence prevent pollution of ground and surface waters, and reduce hazards to nearby property. Options for operational practices and restoration procedures are discussed in relation to the control of degradation processes and polluting potential. Included in these options are design and operation of leachate and gas collection/treatment systems, phasing of landfilling operations, and progressive restoration of sites. Monitoring requirements are emphasized as a vital measure of the success or failure of site designs and operational practices in ensuring that appropriate environmental protection is achieved and maintained.
Design Water Levels in Tidal River Systems under the Influence of Typhoons
Authors: WEBSTER P. , WARDLAW R. B.
Published: July 2007

Water levels in tidal rivers are subject to the influence of both fluvial and tidal factors. The interaction between these factors is rendered more complex in regions affected by typhoons, which typically result in the combined occurrence of heavy rainfall and high sea levels.

Previous studies have outlined an analytical approach for calculating design water levels based on dividing the fluvial and tidal series into a typhoon and a non‐typhoon component. This paper illustrates the steps involved in the analytical approach and describes its application to drainage basins in Hong Kong.

The approach provides a practical means for calculating design water levels, and is recommended for final design purposes. The results of using the full analysis may be approximated by using a sub‐set of analytical results, and should prove satisfactory for the purposes of outline design.
King's Lynn Sewer Improvements
Authors: THOMPSON J. L. , MARTIN P.
Published: July 2007

King's Lynn is a typical English port and market town, located at the edge of the very flat fenland area in East Anglia. The town doubled in size to its present population of 40000 from the end of the Second World War. Although the sewerage system expanded with the growth of the town, the prevailing flat gradients gave rise to much sedimentation and loss of capacity, while tide‐locked outfalls restricted freedom of flow from the storm‐overflow facilities. The result was widespread flooding in many areas of the town during relatively minor storms. This paper describes the studies which were carried out using computer simulation methods to identify the weaknesses and deficiencies of the complex sewerage system, and the innovative tunnelling solution which was adopted to overcome the problems. An indication is also given of the benefits of good public relations when working across the urban environment.
Possible Environmental Impact of the Closure of Two Collieries in County Durham
Authors: YOUNGER P. L.
Published: July 2007

In County Durham the forthcoming closure of two coastal collieries is, in effect, the final closure of a large hydraulically interconnected coalfield which has been progressively dewatered over three centuries. Groundwater will gradually rise through the previously worked strata after the cessation of coalfield dewatering. Past experience shows that the rising groundwater will develop high acidity and heavy metal loadings as oxidized pyrite remnants are dissolved. Conceptual modelling suggests that this acidic groundwater will ultimately discharge into the River Wear and its tributaries, with serious consequences for the aquatic ecology and human use of the River Wear system. Further environmental impacts may include (a) groundwater pollution in the adjacent Basal Permian Sands aquifer, (b) leaching from landfills intersected by the rising water table, (c) compromised integrity of foundations, (d) increased flows in old sewers below the new rest water level (leading to problems at sewagetreatment works and combined sewer overflows), (e) corrosion of other buried services, (f) surface gas emissions, and (g) long‐term subsidence risk from old workings. The prevention of these impacts would involve long‐term maintenance of regional dewatering, although local mitigation of most effects could be arranged – albeit at considerable cost. Current legislation fails to place responsibility for the prevention of such environmental impacts in the hands of any one organization; this ‘vacuum of responsibility’needs to be addressed urgently if a pragmatic, consensual approach to environmental protection in abandoned coalfields is to be pursued.
Drinking Water: Future Quality Requirements
Authors: PACKHAM R. F.
Published: July 2007

Regulations governing the quality of drinking water within the European Community must be based on Directive 80/778/EC, although Member States may impose tighter or additional limits if they so wish. The Directive is substantially derived from standards set by the World Health Organisation (WHO) in 1970. Revised ‘Guidelines Values’for water contaminants were issued by WHO in 1984, and a further revision will be published in 1993. Modest changes in the guidelines set by WHO for microbiological parameters since 1970 have been accompanied by a large increase in the number of limits set for chemical parameters. This is particularly marked for organic compounds including pesticides and disinfection byproducts. The new WHO guidelines will inevitably have an impact on water supplies in the UK, but the timescale for a significant change in the outmoded EC Directive is uncertain.
Contaminated Land and Aquifer Protection
Authors: PATRICIA HENTON M. , YOUNG P. J.
Published: July 2007

The paper discusses the definition of contaminated land, its legislative controls, how it is identified and how a hazard ranking exercise may be carried out on a property portfolio in order to deal constructively with the problem of contaminated land. Such land is important because it can have substantial financial penalties attached to its investigation and remediation. The potential liabilities now arising from environmental impairment are such that anyone involved in the acquisition, ownership or disposal of land has to take an interest in it. The legislative background and environmental policy considerations which affect contaminated land are described, as well as the role of the National Rivers Authority in dealing with the subject. The principal types and sources of contaminated land are identified and current guidelines and standards for dealing with it are discussed. A technique developed for Scottish Enterprise whereby a property portfolio can be ranked in order of its potential hazard by combining the sensitivity of a site with its contamination potential in order to define environmental risk is described, and the necessity to seek professional and experienced advice in evaluating the consequences of contaminated land is highlighted.
Statutory Water Quality Objectives and River Water Quality
Authors: SEAGER J.
Published: July 2007

This paper summarizes some of the key issues which have been considered in developing proposals for a scheme of classifying river quality for the purpose of setting water quality objectives on a statutory basis. Particular attention is given to (a) the relationship between use‐related and general water quality targets, (b) the role of biological assessment, and (c) the requirements of EC directives. Following widespread consultation on the proposals, it was concluded that a clear distinction should be made between sets of ‘use classes’which would serve to set statutory water quality objectives (SWQOs) and a general quality assessment scheme which would be applied independently to assess trends and general progress over a period of time. Once the classification scheme has been established by the Secretaries of State through regulations, SWQOs will be introduced to river stretches in a number of ‘pilot’catchments across England and Wales, following local consultation. The setting of SWQOs will provide the focus for local decision‐making on what the appropriate level of water quality should be – taking into account the desired uses of rivers, what will be required to achieve them, and the associated costs.