bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey to Detect Legionella pneumophila in Potable Waters in North West England
Authors: JONES F. , ASHCROFT CLARE
Published: July 2007

Legionella PNEUMOPHILA is a causative agent of respiratory illness in humans. The organism is ubiquitous and commonly frequents aquatic environments. Incidents of legionellosis have been linked with potable water supplies.

An attempt has been made to determine the degree of contamination, if any, by L. pneumophila in samples of potable water treated and distributed to domestic premises in the north west of England. Sampling was initiated in February 1986 and continued throughout the summer months of 1986 and 1987. The majority of sampling sites were chosen at random, but from areas suspected of having dirty water problems or low chlorine residuals. In a few cases samples were taken where there was a known problem, such as a consumer complaint or bacteriological failure.

Results indicate that public potable water supplied in this area does not constitute a significant health risk in the transmission of the disease. Other environmnental factors appear more significant.
Performance Comparisons Between Water Authorities
Authors: SHEARER D. M.
Published: July 2007

Measurement OF PERFORMANCE in organizations supplying water services has always been difficult because tangible inputs of money and manpower are used to produce outputs of intangible service benefits to customers.

This paper describes the methods which have been developed in the Regional Water Authorities (RWAs) in England and Wales to overcome these difficulties. Performance comparisons have been shown to be a powerful substitute for attempts to measure absolute performance. Particular reference is made to National Performance Ratios (NPRs), the Water Authorities Association (WAA) National Databanks, and to bipartite comparisons between individual authorities and the ways in which the results from these can be usd to improve performance.

The paper concludes with a brief look forward to the future of performance measurement and comparison as the water industry moves towards privatization.
Water Quality Management in the River Calder Catchment
Authors: HUDSON J. A. , MORRIS The Late J. , SWANWICK K. H.
Published: July 2007

The PAPER DESCRIBES the many and complex water and sewage treatment problems in the River Calder valley, followed by summaries of the progress made to date and the plans that have been developed to eliminate these problems in the future. The final section describes how a sludge treatment and disposal strategy was evolved for the whole West Yorkshire conurbation, in effect the Calder valley plus the populous section of the Aire valley including the cities of Bradford and Leeds. The first phase of this strategy, the construction of a new dewatering and incineration facility at Esholt (Bradford) was in progress and plans for a second, larger installation in the Calder valley were being examined.
4. Pollution Risks and Countermeasures for Surface Water Intakes
Authors: COLE J. A. , HAWKER P. J. , LAWSON J. D. , MONTGOMERY H. A. C.
Published: July 2007

The risks and severity of pollution events affecting surface waters have to be assessed from an inventory of pollution threats in each catchment, from regional and national statistics on pollution incidents, and from measurements on the travel and dispersal of pollutants in water courses. Inspection of factory premises, farms, and sewage treatment works commonly reveals ways of stopping potential sources of pollution. Other countermeasures include: bunding of chemical stores and handling areas; processing waste liquors on site; promptly notifying tanker accidents and other spills; broad band monitoring of river water quality; control of intake, buffer storage and water treatment, in light of pollution arrival and chemical data.
Flooding and the Quantification of ‘Intangibles’
Authors: GREEN C. H. , PENNING‐ROWSELL E. C.
Published: July 2007

Sources of both systemic and parameter uncertinties in flood alleviation cost‐benefit analysis are discussed. Cost‐benefit analyses are assessments of the future effects of different scheme options; consequently, there are inherent uncertainties. The omission of consideration of some impacts as ‘intangibles’, because it has not been possible to measure them, is a form of systemic uncertainty.

A significant omission in the past from flood alleviation cost‐benefit analyses has been the non‐monetary impacts of flooding upon households. It is shown that these impacts are both large and more important to the households affected than are the direct monetary losses.
Insurance, Risk Improvement and Management
Authors: SALTHOUSE R. J. W.
Published: July 2007

The importance of adequate insurance in its many and varied forms may often be overlooked in the planning of new projects and developments or the maintenance of existing ones. The consequences can be catastrophic. The insurers are natural risk‐takers, and the emphasis in this paper is on the role to be played by each party in aiming at suitable premiums, cover, terms, and risk and management philosophies.
The Effects of a Timber Preservative Spillage on the Ecology of the River Lossie
Authors: McNEILL A.
Published: July 2007

This study examines the effects of timber preservative spillages on the ecology of the River Lossie whilst the river's quality was recovering following the removal of an unsatisfactory discharge of sewage effluent. The effects of spillages on a minor tributary of the River Lossie are also presented.
Improving Rural Supplies in Northumberland
Authors: JAMES D. B. , DRAGE B. E.
Published: July 2007

A strategy is described which was adopted to ensure compliance with the EC Directive on Drinking Water, at six rural locations in Northumberland. These areas, plus a more widespread community in the Tyne Valley, are served by Catcleugh reservoir, a typical upland coloured source. Treatment of the smaller locations was carried out by single‐stage pressure‐filter plants, and for the larger area by a two‐stage treatment works.

Three of the small pressure‐filtration plants have been closed, and the supply has been replaced from the two‐stage plant. In the other three cases, two improvements are complete: one a dissolved‐air flotation scheme, the other low‐rate single‐stage pressure filtration. Improvements to the third station are in the planning stage.
Laboratory Simulation of Disinfection Regimes for Trihalomethane Control
Authors: GRAHAM N. J. D. , REYNOLDS G. , BUCKLEY D. , PERRY R. , CROLL B.
Published: July 2007

A collaborative project between Anglian Water and Imperial College has been undertaken to investigate alternative disinfection regimes for the control of trihalomethane (THM) formation in lowland surface water treatment. A laboratory experimental protocol has been developed to measure THM formation as a consequence of both pre‐ and post‐disinfection stages with chlorine dioxide, ozone and potassium permanganate, evaluated as alternative pre‐disinfectants in direct comparison with breakpoint and sub‐breakpoint pre‐chlorination. The protocol has been applied to raw water samples from eight locations within the Anglian Water region under winter and summer conditions.

The results have shown that THM formation can be reduced substantially, either by the application of chlorine dioxide and ozone as substitutes to breakpoint pre‐chlorination or by reducing the prechlorination dose. The application of potassium permanganate as a pre‐disinfectant had little effect on diminishing the formation of THM compounds. A further substantial reduction in THM formation can be achieved by diminishing the contact period following post‐chlorination between free‐chlorine and the treated water (e.g. by conversion of free‐chlorine to combined‐chlorine through reaction with ammonium sulphate).
The Management and Control of Urban Runoff Quality
Authors: ELLIS Professor J. B.
Published: July 2007

WaterQUALITY problems from impermeable urban surface runoff are presenting increasingly significant effects at both the short‐term, acute, and longer term, chronic, timescale. The paper identifies the anachronisms in, and the diversity of, historical organizational responsibilities for urban runoff as being a principal mitigating factor in limiting satisfactory, cost‐effective, catchment control. It is recommended that effective source control procedures for stormwater runoff control must form the basis for best practical options for achieving integrated pollution control in urban catchments.
Cement‐based Stabilization of Wastes: Practical and Theoretical Considerations
Authors: SOLLARS C. J. , PERRY R.
Published: July 2007

Rapidly changing public and political attitudes to the environmental implications of industrial waste disposal are forcing a re‐evaluation of the longstanding practice of directly landfilling such waste, either in a mono‐disposal or co‐disposal manner. As a result, more technology‐orientated solutions to industrial waste disposal are being evaluated. This paper describes one such process, cement‐based stabilization/solidification, and examines its physicochemical basis, present‐day application and potential future uses, and outlines areas where research into fundamental and practical aspects of the process are needed.
The Impact of Flue‐gas Desulphurization on the Water Environment
Authors: TAYLOR M. R. G. , HEATON R. , BATY R.
Published: July 2007

Electricity generation in the UK is dominated by fossil fuels, principally coal. In order to reduce emissions of sulphur dioxide to the atmosphere new fossil fuel‐fired power stations will be equipped with flue‐gas desulphurization (FGD) facilities, and in the short term the Central Electricity Generating Board proposes to retrofit FGD systems to 6000 MW of its coal‐fired generation capacity, including the 4000‐MW station at Drax. The first generation of these plants will be based on the limestone‐gypsum process.

In addition to the product gypsum the process generates a liquid effluent as a result of the need to remove chloride from the process inter alia to protect gypsum quality. This effluent also contains other contaminants such as metals, fluoride and nitrate, and a mathematical model has been developed to predict effluent volumes and composition as a function of different coal, limestone and process water combinations. The model also calculates the effect of the discharge of this effluent on a receiving watercourse, both untreated and following treatment based on neutralization and precipitation/sedimentation.

The paper discusses the development of the mathematical model and the impact of treated FGD effluent on power station cooling‐water discharges, via which the effluent would normally be discharged, for both once‐through and recirculating cooling systems used at coastal and inland stations respectively.
The EC Directive on Drinking Water (EEC 80/778)
Authors: BREACH R. A.
Published: July 2007

The background to and technical deficiencies of the EC Drinking Water Directive are discussed. Although the inadequacies of the Directive are becoming increasingly recognized, there is no doubt that it has had a major impact on the UK water industry, much of which will be beneficial in the long term. However, it has provided a significant challenge to water suppliers on technical and environmental issues, as well as in new areas such as publicity and customer awareness. The water industry should be seen to be responding to the situation vigorously and positively to meet the spirit of the Directive, whilst seeking technical refinements which will make it a more practicable piece of legislation for the future.
The Use of Redox Potential to Control Ferric Sulphate Dosing during Phosphate Removal
Authors: KERRISON P. H. , McEWEN B. , PHILLIPS G. L. , CROOK B. V.
Published: July 2007

In recent years, the Norfolk Broads have been enriched with sewage effluent and runoff from heavily fertilized land. Nitrogen and phosphorus compounds from these sources can cause ecological problems by stimulating increase in algal biomass in the water, so part of Anglian Water's programme of research in Broadland has been to remove phosphate from major sewage effluents discharged to the Rivers Ant and Bure. This is achieved by dosing ferric sulphate to secondary effluent and settling the resultant insoluble complex.

At three sites on the River Bure, the performance of timeclock‐ and redox‐based dose control systems was evaluated. Redox control, by restricting dosing when phosphate load was low, increased the efficiency of phosphate removal and produced up to 19 per cent savings in chemical costs. Modifications are described which made the system self‐regulating and ensured that savings were not eroded by maintenance costs. The system now operates efficiently and routinely at major sites on the Rivers Ant and Bure.
Wellfield Development for Urban Water Supplies in PDR Yemen
Authors: DAVEY J. C.
Published: July 2007

Internationally‐funded groundwater projects have recently been completed for the main urban areas of PDR Yemen. The necessary resources to secure potable supplies into the next century have been proved in Cretaceous sandstone, Eocene limestone and Quaternary clastic aquifers, and their investigation has highlighted the importance of comprehensive hydrogeological studies prior to permanent works design and construction. The projects discussed will improve the quantity, quality and accessibility of potable water to nearly one third of the country's population.
Chlorinated Solvents in UK Aquifers
Authors: RIVETT M. O. , LERNER D. N. , LLOYD J. W.
Published: July 2007

The paper reviews background data on chlorinated solvents and all published data on chlorinated solvents in UK groundwaters. New data from an aquifer‐wide survey of the organic water quality of the Birmingham aquifer (carried out by the University of Birmingham and the Water Research Centre (WRc)) show that contamination by chlorinated solvents is extensive and is greater than that observed in previously published UK studies. Trichloroethylene contamination is particularly apparent in the Birmingham aquifer, with 40% of the boreholes sampled containing waters above the new UK limit for this contaminant. Fortunately the Birmingham aquifer is not used for public supply. Land use and hydrogeological factors are shown to influence the contamination observed in particular boreholes. The difficulties associated with locating contaminated zones in aquifers, due to the immiscible flow of chlorinated solvents, are indicated. It is concluded that the occurrence of chlorinated solvents in groundwaters makes a significant contribution to the poor water quality of many UK aquifers that underlie, or are close to, urban and industrial areas.
Water Treatment for Health Hazards
Authors: AINSWORTH R. G.
Published: July 2007

The performance of treatment processes is reviewed for the removal of five potential water contaminants, i.e. pesticides; volatile organic solvents; nitrates; Cryptosporidium oocysts; and Giardia cysts.

Technologies for organic solvents and nitrate removal are well advanced and in operation. Adsorption on activated carbon is available for pesticides removal, but more information is required to assist in selection and operation; new processes are also required. Physicochemical treatment can remove Giardia, but optimization and control are critical factors. Unfortunately little is known about Cryptosporidium removal. Ozone is more effective than chlorine for inactivating both Cryptosporidium and Giardia that have penetrated the treatment train.
Microbiological Aspects of Water Quality and Health
Authors: DADSWELL J. V.
Published: July 2007

Historically, typhoid and cholera are well‐recognized waterborne infections. Advances in laboratory techniques over the past 20 years have enabled a wide range of other faccally‐excreted bacteria, viruses and protozoa to be identified as causing gastrointestinal infections. Record outbreaks are referred to where some of these micro‐organisms have been spread by the contamination of drinking water, either at source or during distribution. This has usually happened when the water was untreated, or where there have been failures of the disinfection process or breaches in the integrity of the distribution system. Recent waterborne outbreaks of cryptosporidiosis have underlined the importance of adequate filtration in the prevention of waterborne transmission of this protozoon, the oocysts of which are completely resistant to the levels of chlorine that can be attained in water treatment practice. An outline is given of the current processes by which pathogenic micro‐organisms are excluded from drinking‐water supplies; their potential deficiencies for dealing with some of the ‘newer’ waterborne pathogens are also discussed.
Trihalomethane Formation during Sludge Bulking Control with Chlorine
Authors: VAN LEEUWEN J. , VAN ROSSUM P. G.
Published: July 2007

Effluent quality implications of bulking control with chlorine in activated‐sludge treatment have been studied on laboratory scale. Batch chlorination of sludge samples led to the formation of trihalomethanes, mainly as chloroform (in hundreds of ùg/l) and even more non‐specified organohalogens. Most organohalogens were formed from substances in the liquid effluent, and fewer out of the sludge solids. The presence of sludge lowered the concentration of extractable trihalomethanes in the effluent. Continuous chlorination in a laboratory‐scale activated‐sludge plant did not produce measurable quantities of any organohalogen compounds.
Excluding Groundwater Infiltration into New Sewers
Authors: FENNER R. A.
Published: July 2007

Much attention has been focused on the need for sewer renovation and rehabilitation of old sewerage systems, but age is not always the reason for sewer failure. Serious problems of performance have also been encountered on sewerage schemes less than 10 years old. This paper considers the problems of groundwater infiltration into new foul sewers, and suggests that deficiencies might exist in some aspects of modern sewer design and construction.

Infiltration is most frequently observed at sewer joints. Results are presented of laboratory tests which show the ability of flexible fixed‐ring joints on clay sewers to withstand both internal and external pressures. Damaged polyester fairings on the spigots of these pipes can act as one‐way valves, and massive infiltration may result. The standard site water test is shown to be inadequate in detecting some of these types of defect which may result from damaged pipes or poor workmanship.
Health Impacts in Developing Countries: New Evidence and New Prospects
Authors: CAIRNCROSS A. M.
Published: July 2007

This review of recent studies of the health impact of water supply and sanitation programmes in developing countries shows that they share many findings, and some methodological problems, with older studies of the subject. Considerable health impacts can occur under appropriate conditions, and it is suggested that the greatest impact can be produced by targeting water and sanitation facilities to those whose existing water sources are furthest away, or whose environment is most faecally polluted.

Another finding is that health benefits stem from the changes in hygiene behaviour which water and sanitation make possible. The measurement of such behavioural changes is a subject in need of development. Nevertheless, it is likely to be easier, more reliable, and more useful to water and sanitation programme managers as an operational evaluation tool than any attempt to measure the health benefits directly.
Red‐List Substances: Selection and Monitoring
Authors: AGG A. R. , ZABEL T. F.
Published: July 2007

The conference of Ministers representing North Sea littoral states, held in November 1987, agreed certain initiatives to reduce inputs of potentially dangerous substances to the North Sea from land‐based sources. The UK Government has responded by proposing reductions of substances on a ‘red list’, selected on the basis of ecotoxicity, persistence, potential for bio‐accumulation and estimated concentration in the environment.

This paper describes the approaches which have been used in selecting candidate substances for the red list and other priority‐setting exercises, highlighting the difficulties presented by the lack of data for individual chemicals and the use of default values.

The estimation of input loads via rivers and direct discharges is discussed, with particular reference to monitoring requirements and analytical performance criteria.
Recent Developments in Oxygenation of the Tidal Thames
Authors: LLOYD P. J. , WHITELAND M. R.
Published: July 2007

Increased polluting loads are discharged to the tidal Thames at times of heavy rainfall. This can lead to a rapid decline in dissolved‐oxygen (DO) concentrations, which, on occasions, has resulted in fish mortality. The problem is caused by the cumulative effect of surface runoff, increased flows from sewage‐treatment works, and storm‐sewage discharges from the combined drainage of Inner London.

An experimental system of in‐river oxygenation has been operated by Thames Water in order to alleviate the problem. This scheme demonstrated that the river oxygenation concept is viable. There was, however, a need to increase the operating reliability of the plant and to provide extra oxygenation capacity. Thames Water carried out a detailed investigation into the various options prior to the acquisition of a new, purpose‐built, self‐propelled, oxygenation vessel, which was delivered to the River Thames in October 1988.
Pre‐Filtration of Very Highly Turbid Waters Using Pebble Matrix Filtration
Authors: RAJAPAKSE J. P. , IVES K. J.
Published: July 2007

As A SOLUTION to very high turbidity problems associated with slow sand filters, a new pretreatment method has been developed at University College, London. Initial experiments with a model using a bed of fine sand (effective diameter d. = 0.32 mm) demonstrated that maximum loadings on slow sand filters should not exceed 25 mg/1 at a filtration velocity of 0.2 m/h for satisfactory run times (approximately 5 weeks). However, a literature survey revealed that many tropical rivers may carry several hundred (or even a few thousand) milligrammes per litre of suspended solids during monssoon periods. A need for pretreatment methods is therefore obvious.

A novel process, called pebble matrix filtration, can protect slow sand filters by reducing the suspended‐solids concentration of monsoon river waters (containing up to 5000 mg/1) to below 25 mg/1. The paper briefly describes the principles lying behind the treatment process of pebble matrix filtration, and suitable operational parameters are given at flow rates of 0.72–1.56 m/h for tested suspended‐solids concentrations of 500, 1000, 2000 and 5000 mg/1 kaolin clay in London tap water, with achieved run times of up to 116 h to head losses not exceeding 1.5 m. Filter cleaning is described by a method called ‘drainage and backwash’.
Comparison of Alternative Operating Modes on the Halifax Activated‐Sludge Plant
Authors: JONES G. A.
Published: July 2007

Since 1981 the activated‐sludge plants at Halifax sewage‐treatment works have been operated in the ‘Halifax’mode, which has successfully prevented previous bulking of the activated sludge. The paper describes an investigation of the ‘Halifax’mode; also the ‘Halifax’mode plus a sludge bypass arrangement. Plant performance, sewage flows, and electricity and oxygen usages were monitored. Practical measurements showed that an increase of 65% in peak final settling tank flow rates could be achieved, and up to twice the BOD load could be treated with the assistance of extra oxygen, using the existing Vitox plant. The improved settling tank performance can be explained in terms of the Water Research Centre's mass loading theory.
Design of Sewage‐Treatment Plants in Brisbane, Australia
Authors: LEVER M. L.
Published: July 2007

Brisbane City Council provides sewage‐treatment facilities for a population of 800 000, together with industrial effluents having an organic loading equivalent to a further 600 000 people. Three projects are described to illustrate some of the different designs and operating parameters used in Brisbane, where the sewage temperatures range from 18°C to 29°C and stormwater is collected separately. The first project is a 400 000 population equivalent augmentation to a conventional activated‐sludge plant located at Luggage Point. The two other plants have to comply, inter alia, with an effluent standard of 10 mg/l for total nitrogen. This requirement, together with site constraints and an economic evaluation of alternatives, resulted in the selection of the extended‐aeration process incorporating anoxic zones and separate mixing and aeration. These contemporary designs are specific to Brisbane conditions, and are intended to facilitate reliable operation as well as being cost effective.
The Avalon Lakes: An Environmental Opportunity
Authors: NEWMAN A. T. , HAWKER P. J.
Published: July 2007

The Avalon Lakes project was a concept to utilize, as water storage reservoirs, shallow basins left by commercial peat exploitation. There are, however, important nature‐conservation interests in the project area. The proposed scheme ultimately incorporated measures to enhance these and, perhaps unusually for a source development, was broadly supported by conservation groups. The related cost was estimated at £4.2M, or 17% of the overall source works’price.

Plans and scientific investigations of the scheme occupied a span of 21 years to 1988. It was eventually abandoned as an option for future water supplies following the restructuring of Wessex Water Authority in preparation for privatization of the water industry. The grounds for terminating the project were substantially concerned with costs, though coloured by lingering apprehension about the consistency of water quality.

There is now a greater public awareness of the adverse environmental effects of water resource developments. It is suggested that this will lead to future schemes, less obviously suited to their surroundings than Avalon, incurring a higher conservation‐related cost in order to gain acceptance.
Design and Construction of the New Bintulu Water Supply, Sarawak, Malaysia
Authors: LAWSON J. D. , BRYANT D. A. W. , HUANG P. WONG HUNG
Published: July 2007

The new Bintulu water supply was built in the early 1980s to serve a major development of the town of Bintulu in Sarawak, East Malaysia, arising from the extraction of natural gas from the South China Sea. The water supply was designed to supply 78 Ml/d. The works comprise earth dams forming a pumped storage reservoir, a river intake, pumping stations, pipelines, a water‐treatment works, treated water storage and a distribution system. The treatment works and distribution system are being built in two phases. The first phase was completed in 1983, and the second phase is to be constructed in 1990–91.

The paper describes the initial planning of the scheme, including water‐demand forecasts, the design and construction of the Phase I works, and problems encountered during its operation. It also highlights the exceptionally rapid implementation programme and stability problems at the main earth dam.
The Blashford Lakes Water Supply Scheme
Authors: EASTWOOD J. C. , ELDER A. J. , PEARSON N.
Published: July 2007

Wessex Water has developed a new 35 Ml/d water supply source, using lakes formed from worked‐out gravel pits, to meet increasing demands for water and to provide security for existing supplies.

Having identified the need for the scheme, an engineering feasibility study was carried out in conjunction with a full environmental assessment. This led to the successful promotion of the Stage I scheme in 1986. Design and construction took place immediately after, and the scheme was officially opened in 1989.

There are opportunities to expand the scheme as more lakes are formed by gravel working, and proposals for this are well advanced. This paper describes all the key elements in the promotion and development of the scheme.
The Wastewater Disposal System of the City of Yokohama, Japan
Authors: MIYAKOSHI S.
Published: July 2007

Modern sewerage system construction in the City of Yokohama dates from 1950. During the ensuing years, the City actively promoted such construction. The first sewage‐treatment plant was commissioned in 1962, and the City's percentage of sewered population (including treatment services) reached 85% in March 1990.

This paper describes the outstanding development and record of the wastewater disposal system in Yokohama (which must be ranked ahead of other Japanese cities in this area), as well as the organization, technology, administrative and financing efforts that made this development possible. It also explains the notable features of these works, which include Japan's first fully‐fledged centralized sludge treatment, improvement of combined sewerage systems, industrial effluent control, effective use of sewage effluent and sludge, and sewer user charges. In addition, it presents comments on the future tasks for the 21st century, including advanced wastewater treatment and the integrated information system on water environment.
Coping with COPA II: Actions to Improve Effluent Quality
Authors: BLACK D. W. , FINDLAY G. E.
Published: July 2007

The paper outlines some of the actions taken by Severn Trent Water to achieve compliance with consent limits since the implementation of the Control of Pollution Act (Part II) in 1985.

Prior to and since 1985, Severn Trent Water has undertaken an extensive programme to analyse the reasons for failure and carry out remedial work. A major feature of this programme, which has been further stimulated by privatization, has been the need to reduce the lead time for carrying out improvements.

The paper discusses the means by which this has been achieved, including the introduction of the ‘fast‐track’initiative and the ‘process matrix’.

Other aspects are outlined including initiatives to develop more robust processes, computerized work scheduling, extensive training programmes and best practice studies.
Estuarine and Coastal Waters: Tenby and Weymouth Case Studies
Authors: NIXON S. C.
Published: July 2007

The use of the sea for sewage disposal has come under increasing scrutiny from the public and from other countries bordering the North Sea. There is a need, therefore, to understand and quantify the environmental impact of sewage discharges from long sea outfalls. Broad‐based environmental surveys were carried out at case‐study outfalls at Tenby and Weymouth over a four‐year period. Studies included (a) sediment sampling on coarse grids and near‐outfall transects, (b) bioassays on mussel scope‐for‐growth and Microtox, and (c) uptake of taint compounds.

Although at both Weymouth and Tenby the whole survey area was affected to some extent by sewage‐derived material, both outfalls were operating within the dispersive and assimilative capacities of the environment, and thus were having minimal effect. The studies indicated that well‐designed and operated long sea outfalls appear to be an acceptable means of domestic waste disposal.
The Occurrence of Coliform Bacteria in the Surface Soils of Two Catchment Areas in the Yorkshire Dales
Authors: HUNTER C. , McDONALD A.
Published: July 2007

The levels of total coliform and Escherichia coli bacteria were determined within the surface soils of two upland catchments in North Yorkshire. The results indicated that enteric bacteria can survive for a sufficient period outside parent faecal material to provide a semi‐permanent land store that might then be capable of contaminating upland waters following transport by hydrological processes. Significant differences in bacterial counts were found between broadly wet and dry soil moisture/vegetation zones in both catchments. This was explained by the more favourable survival conditions found where the soil moisture content was high enough to prevent the rapid desiccation and death of enteric bacteria. Significant differences were also found between the counts of total coliform and Escherichia coli bacteria in surface soils. It was concluded that the use of the total coliform group alone, as an indicator of the degree of sanitary bacterial contamination of soils, may over‐estimate the true extent of contamination.
Developments in Health‐Related Quality Standards for Chemicals in Drinking Water
Authors: FAWELL J. K.
Published: July 2007

Small differences in water quality standards can mean huge differences in costs for water treatment; difficulties which are compounded by standards for which the derivation is unclear, such as the EC drinking water Directive. Such situations give no indication of the margin of safety for a parameter or the significance to consumers of exceedances. The WHO Guidelines are being revised and will be presented so that the precise derivation of the numbers is absolutely clear. The scientific and quasi‐scientific considerations can be separated and the user given the appropriate information to adapt the guidelines to particular circumstances. In deriving standards for toxicological data the factors incorporated reflect uncertainties in the data and extrapolation from animals to man. Understanding the mechanisms of toxicity or carcinogenicity can reduce the uncertainty and improve the quality of the standard, often allowing higher figures to be used with confidence that public health will not be comprised.
The Development of a Control Policy for Fish Farming
Authors: SMITH H. , HAIG A. J. N.
Published: July 2007

The polluting effects of fish farming have been well‐documented, but the scale of the problem and the difficulty in effectively controlling the industry are less well known. In approximately twenty years, production by this industry in Scotland has increased by two orders of magnitude and it has been estimated that the population equivalent of fish farming effluents is as high as 1.5 million.

The development of a pollution control policy for both land‐based and floating‐cage farms is described. The role of other controlling agencies is discussed and legislative weaknesses are identified. In addition, the industry's reaction to pollution control is highlighted.

Polluting discharges are not controlled only through the issuing of consents, but effective monitoring is also required. Resource constraints resulted in a policy which includes the requirement of certain fish farmers to self‐monitor their activities.
The Roadford Scheme: Minimizing Environmental Impact on Affected Catchments
Authors: LAWSON J. D. , SAMBROOK H. T. , SOLOMON D. J. , WEILDING G.
Published: July 2007

Roadford reservoir, located in the River Tamar catchment and commissioned in 1989, operates in conjunction with two other reservoirs and increased abstraction from six rivers in North and South Devon. The scheme affects the flow regime in all rivers, as well as their water quality, ecology and, particularly, their important salmon and sea trout fisheries. The paper describes how the detailed operating rules for the scheme have been designed to minimize the impact on the environment by means of changes to the flow regime, without jeopardizing the yield of the scheme. The complex operating rules include the zoning of the reservoir storage, varying prescribed minimum flows, spate sparing rules, and special releases for fisheries purposes. A programme of environmental monitoring will allow further refinement of the operating rules.
Groundwater Pollution Arising from the Disposal of Creosote Waste
Authors: ARVIN E. , FLYVBJERG J.
Published: July 2007

Creosote‐contaminated groundwater contains a complex mixture of phenols, aromatic hydrocarbons and nitrogen‐, sulphur‐ or oxygen‐containing heterocyclic, aromatic compounds. One of the most important factors that limits the spreading of these contaminants in groundwater aquifers is degradation by subsurface micro‐organisms.

This paper gives an overview of the present knowledge about microbial degradation of creosote contaminants under aerobic and anaerobic conditions. Furthermore, various techniques for biological remediation of creosote‐contaminated groundwater are outlined. These techniques include enhancement of the native population of subsurface micro‐organisms to degrade the contaminants (in situ treatment) and withdrawal of the groundwater followed by treatment by various wastewater treatment processes (above‐ground treatment).
Approaches to the Assessment and Remediation of Polluted Land in Europe and America
Authors: GRIFFITHS C. M. , BOARD N. P.
Published: July 2007

The approach to the investigation of contamination is similar in both Europe and North America. However, the assessment of the resultant data can and does vary significantly. This paper seeks to address the concepts employed in contamination assessment in the UK, mainland Europe, Canada and the US. Details are presented of the relevant legislation in each country and the governmental guidance which is issued. Comparisons are made of the approach to the assessment and remediation that would be adopted for sites with identified levels of chemical contamination. The paper also looks forward and expresses views on how the approaches may progress over the next five years.
The Protection of Urban Groundwater from Pollution
Authors: LERNER D. N. , TELLAM J. H.
Published: July 2007

The serious pollution of groundwater under cities is demonstrated with data from Coventry (UK), Madras (India) and Birmingham (UK). Microbiological organisms, nitrates, and organic chemicals are common, but many other pollutants are also found. The main sources are industry and inadequate sewerage. The provision of sewerage must remain a priority, on health grounds, for cities in the developing world. Virtually all industrial sites pollute the soil and groundwater through careless handling of chemicals. Industrial sites should be treated like landfills: contained and carefully monitored. If industrialists had to use groundwater from below their own sites, they would suffer the consequences of any pollution. This would also clean up the aquifer by pumping out polluted water.
Practical Aspects of Yield Investigations of Groundwater Sources
Authors: GROUT M. W. , ALEXANDER D. W. , SIMPSON R. J.
Published: July 2007

Lee Valley Water plc has, in a joint study with the University of Birmingham, been reassessing the reliable yields of its existing chalk sources in order to make maximum use of the available groundwater resources. An approach to yield assessment was developed which took into account the hydrogeology and flow processes in the vicinity of pumping stations, and within the contributing area. The yield of many sources was found to be very dependent on regional water level conditions. Initial estimates of potential yields were made but future monitoring should aim to clarify the interrelationship between source output and aquifer state.
Impacts of Climatic Change on River Flow Regimes in the UK
Authors: ARNELL N. W.
Published: July 2007

Much has been written in recent years about the potential threats posed by increasing greenhouse gas concentrations. This paper summarizes the implications of global warming for hydrological processes in general and river flow characteristics in the UK in particular, emphasizing the present high degree of uncertainty. Current climate change scenarios for the UK imply that rainfall between autumn and spring will increase, and this may have beneficial implications for UK water resources. However, the effect of this increase may be outweighed by higher evapotranspiration. Average annual runoff in a catchment in southern UK may be reduced by around 5% by the middle of the next century, but this estimate is very uncertain: runoff may reduce by 30% or increase by 30%. Runoff in northern and western UK is likely to show a slight increase (but with similarly large confidence intervals). It is probable that river flows in the UK will be much more concentrated in winter than at present. The effect of a given climate change scenario on monthly flow regimes depends on the current summer water balance and on catchment geological conditions.
The Translocation of Some Herbicides between Soil and Water in a Small Catchment
Authors: MATTHIESSEN P. , ALLCHIN C. , WILLIAMS R. J. , BIRD S. C. , BROOKE D. , GLENDINNING P. J.
Published: July 2007

This paper presents data on the distribution of four herbicides within an agricultural catchment. In the case of mecoprop, 2,4‐dichlorophenoxyacetic acid and simazine, these data include concentrations in the soil, field drains and the stream, before and after applications of the herbicides following good agricultural practice. The concentrations of these herbicides in the soil were found to follow published degradation rates, and their concentrations in the stream and drains were elevated following rainfall with peak concentrations from 0.12 μg/1 to 68.0 μg/1. Atrazine was found at relatively high concentrations (peak 122 μg/1) when it had not been applied to any of the fields draining to the sampling point.

The data will be used to test models that may be used as one of a number of tools for the screening of new pesticides prior to their registration. One approach using the Mackay's fugacity model is outlined.
Sewage Sludge Disposal in the UK: A New Challenge for the Next Twenty Years (Abridged)
Authors: MATTHEWS P. J.
Published: July 2007

The paper attempts to review current and future practices in the UK against a European background.

Sludge disposal has become a subject which is developing rapidly again and, since the presentation of this paper, there have been a number of developments, e.g. the adoption by the EC of its hazardous waste Directive in December 1991. Untreated sludge or sludge which is unsuitable for use in agriculture will be classified as a hazardous waste, subject to certain criteria. This makes the work on sludge classification even more crucial.
The Management and Creation of Beaches for Coastal Defence
Authors: RIDDELL K. J. , YOUNG S. W.
Published: July 2007

The creation and management of beaches using natural mobile materials can often provide a cost‐effective and environmentally appropriate coastal defence. This paper summarizes recent practical endeavours in beach creation and management. Reference is made to the natural sources of beach building materials and to the numerical and physical models that may be employed to assist in the definition both of material transport paths and their magnitude. Risk analysis is noted to be a necessary part of the beach design process together with an appraisal of the coastal hydrodynamics and topographical constraints of the site of interest. The techniques that have been employed to recycle beach materials on some frontages are described, with comments on bypassing materials around obstructions. The paper describes the important considerations to be made when material is being imported to a beach, and notes some of the presently used techniques. Important points are drawn out for the future of beach creation and management, and a number of research needs and administrative difficulties are highlighted.
Asset Management Planning: Theory and Practice
Authors: LINDLEY E.
Published: July 2007

In 1988, water undertakers in England and Wales were charged with producing asset management plans as a prelude to privatization. These plans had to provide an auditable statement with respect to the condition and performance of underground assets, with a view to defining and setting priorities for investment requirements.

Some water authorities were ill‐prepared for producing the required formalized plans, resulting in variable confidence limits being placed on the identified investment requirements. A need existed to refine most plans, which was reinforced by a statutory requirement to update the asset management plans.

This paper deals particularly with water distribution systems and provides an insight into the production of asset management plans. A brief review of the current approach used by a certain major water plc, to update and refine their plans, is also included. The contribution of asset management plans to the effective management of distribution network investment and operation in England and Wales should not be underestimated and is equally relevant in Scotland.
Conservation in a Privatized Water Industry: The Anglian Water Experience
Authors: WOODCOCK P.
Published: July 2007

Anglian Water has adopted a positive approach to conservation. This forms an integral part of the Company's environmental policy which includes a commitment to full compliance with the Code of Practice on Conservation, Access and Recreation and acknowledges the Company's statutory responsibilities towards conservation.

The Company is actively incorporating conservation considerations into routine environmental assessment of a growing capital programme. The implementation of nature conservation and landscaping initiatives is making an important contribution to the wildlife and visual amenity of the Company's sites. Management plans and nature reserve agreements have been prepared for operational sites including the 10% of the Company's land which has been designated by English Nature as of Site of Special Scientific Interest status. Buildings and objects of cultural heritage interest are being restored and displayed, and the Company supports archaeological investigations around the Anglian region.

Anglian is promoting awareness of conservation issues, and of its work, through support for environmental projects within the community. Regular dialogue with conservation organizations forms an important component of the Company's conservation work.
Requirements for Quality System Certification to BS 5750 with Reference to the Water Industry
Authors: BOON EUR. ING. J.
Published: July 2007

Quality assurance for the water industry and its suppliers is being seen to be of ever‐increasing importance as a means of meeting the demands of customers and giving confidence to regulators. The creation of the Water Industry Certification Scheme demonstrates the industry's increased level of commitment to quality assurance.

This paper considers the requirements and benefits of certification of quality systems with particular reference to the BS 5750/EN 29000/ISO 9000 series of standards. The requirements for certification in the water industry are discussed in terms of corporate policy, what is stated in the standard, and how the requirements of some elements of the standard might be interpreted by a certification body.
Health Hazards in the Use of Buildings
Authors: O'SULLIVAN P.
Published: July 2007

The paper addresses the question of what is a ‘healthy’building, and whether the definition normally expressed in terms of occupant well‐being has changed over a period of time. This definition is considered in relation to the relevant physical correlates, and suggested that they support the idea of the light, airy building. Air quality is then investigated to see how it can be, and perhaps more importantly how it is, incorporated into current solutions. Two design approaches are suggested from which a decision can be made as to use and profit from the shape of buildings; these are climatically rejecting and climatically interactive, and the use of either can result in solutions of differing orders of technical complexity. Finally it is suggested that some of these orders of complexity of solution are more difficult to operate healthily than others, and indications are given of possible ways ahead.
Composting Sewage Sludge: Basic Principles and Opportunities in the UK
Authors: CARROLL BARBARA A. , CAUNT P. , CUNLIFFE G.
Published: July 2007

The basic principles of composting are applied to the treatment of sewage sludge. Composting systems are reviewed, and it is demonstrated by reference to international experience that composting is a viable method for sludge treatment. Current attitudes and approaches to the composting option in the UK are discussed and opportunities for further development are identified.