bluuebunny/crossref_metadata_2025 huggingface dataset:
CHARM ‐ A Flow Management Model for the Lower River Thames
Authors: Wilkinson J. C. , Von LANY P. H.
Published: July 2007

This PAPER DESCRIBES the development, testing, and implementation of CHARM, a low flow management model for the River Thames between Windsor and Teddington. CHARM has been designed to help operational control staff to regulate river water levels and to define safe abstraction rates for pumping from the river into reservoir storage. Effective management of flows, levels, and abstraction rates is particularly important during periods of low flow when there is a potential conflict of interest between meeting the demand for water and satisfying minimum constraints for residual river flows and levels.

CHARM resides on a microcomputer and evaluates the consequences of a contemplated set of actions, over a 24 hr period, within a matter of seconds. Results are displayed graphically to the operators, showing where constraints have been violated so that control decisions may be adopted or modified as necessary.
Drinking Water Standards and Risk Assessment
Authors: COTRUVO J. A.
Published: July 2007

The role and use of risk assessment methods in the establishment of drinking water standards are described, with emphasis on recent applications in the USA. The process essentially includes an attempt to quantify human exposure from all routes including drinking water, animal toxicology and human epidemiology, when available, to arrive at drinking water concentrations at which exposure would result in ‘no known or anticipated adverse effects on health, with a margin of safety’. The process itself is straightforward; however, the application to decision making for substances which are considered to be potentially non‐threshold acting in their toxicity (e.g. carcinogenic) requires many policy choices beyond the scientific data, and is subject to considerable controversy.
Optimization of Water Supply Systems: Risk Analysis and Reliability of Supply
Authors: WARREN R. P. , COOK S. C. , LUMBERS J. P. , FANNER P.
Published: July 2007

The problem of determining minimum premissible storage in the optimization of water distribution networks is assessed by means of evaluating the reliability of the system operation during range crisis events. Reliability is treated in both a deterministic and probabilistic manner, and an illustration of the analysis given for a typical scenario on an existing network.
EC Directive on the Control of Dangerous Substances (76/464/EEC): Its Impact on the UK Water Industry
Authors: AGG A. R. , ZABEL T. F.
Published: July 2007

This paper discusses the impact on the UK water industry of EC legislation which has been adopted and proposed for the control of dangerous substances discharged to the aquatic environment. The main impact arises from the increased monitoring needs, requiring more sophisticated analytical equipment and skilled staff, together with the increased administrative burden to produce reduction programmes and to set and control consents for dangerous substances. The paper also summarizes recent initiatives which have been taken by the UK towards a more precautionary approach to pollution control, by requiring that ‘red‐list’ substances should be controlled by environmental quality standards and limit values whichever are the more stringent.
The Agricultural Requirement for Irrigation Water
Authors: BAILEY R. J. , MINHINICK J.
Published: July 2007

This paper presents a quantitative analysis of irrigation requirements in different climatic areas of England and Wales. The analysis takes account of the differing requirements of various crops and variation in soil texture. The results include an estimation of irrigation requirement in an average year, a typical dry year for irrigation planning purposes, and an exceptional year such as 1976. The analysis was conducted using a computer programme developed jointly by the Agricultural Development and Advisory Service of the Ministry of Agriculture, Fisheries and Food, together with the Meteorological Office, and a brief description is given of the salient features of the programme.
Optimum Design of Sewage Sludge Consolidation Tanks
Authors: HOYLAND G. , DEE A. , DAY M.
Published: July 2007

Consolidation is potentially the most cost‐effective of all sludge treatment processes. However, traditional design procedures have been oversimplified such that the process has not generally been fully exploited.

The objective of this report is to summarize the Water Research Centre (WRc) procedure for sizing sewage sludge consolidation tanks, and explain the major design aspects which control the effective operation of the plant. The procedure provides a means of sizing tanks to consolidate any particular sewage sludge to any solids concentrations up to the maximum, and is applicable to both the batch and continuous operational modes. To obtain the predicted performance, the essential equipment such as the picket fence and control system, comprising a consolidation plant, must be suitably designed.
Sediments in Sewers
Authors: CRABTREE R. W.
Published: July 2007

A recent survey has suggested that up to 25 000 km of UK sewerage networks may be affected by in‐pipe sediment deposits. Field evidence indicates that, typically, up to 90% of the pollution load discharged from storm sewage overflows may be derived from the erosion of accumulated in‐system sediment, commonly referred to as silt.

A sewer flow quality simulation model is being developed under the aegis of the WRc/Water Industry Collaborative River Basin Management research programme. Such a model will enable sewerage engineers and water quality planners to produce more effective designs for sewerage rehabilitation schemes to control river pollution. In order to produce this model it is necessary to understand the nature, characteristics and controlling mechanisms of in‐pipe sediment deposits.

Field observations, coupled with sampling and analysis of combined sewer sediment deposits, have produced a five category classification for such sediments. Each category has distinctive characteristics in terms of appearance, composition and polluting potential.
Comparison of Disinfection Techniques for Sewage and Sewage Effluents
Authors: RUDD T. , HOPKINSON L. M.
Published: July 2007

This paper reviews operational and experimental disinfection techniques for the removal of pathogens from sewage and secondary effluent prior to marine discharge. Disinfection options considered include chlorine (hypochlorite, chloramines, OSEC), ultraviolet light (UV), ozone, chlorine dioxide, bromine chloride, peracetic acid (PAA) and gamma irradiation. A comparison of alternative systems is made in terms of their inactivation efficiency, safety, environmental impact and cost. Budget costs were obtained from chemical and equipment suppliers for the disinfection of a theoretical case‐study, to enable a direct cost‐comparison to be made.
Water Aid and the Third World ‐ a Partnership in Low‐cost Technology
Authors: RICHARDSON IMELDA A.
Published: July 2007

Wateraid, a registered charity, is working with local partners in Africa and Asia on small‐scale primary water supply projects, basic sanitation and hygiene education, for poor Third‐World communities. Programmes are aimed at lasting development, not disaster relief. Low‐cost technologies are used, preferably including proven local techniques. This, combined with training local staff, increases the probability of replication occurring through WaterAid's local operational partners.

Methods employed fully involve the benefiting community; their participation is of course essential if they are to run and maintain their new supply successfully.

Finally it is expected that poor communities achieving their own protected water supply will gain confidence to tackle other development needs.
Catchment Afforestation and Water Supply in Strathclyde Region
Authors: GREENE L. A. , TAYLOR J. A.
Published: July 2007

The intensive afforestation of the uplands in Strathclyde Region, encouraged by Government policy, has given rise to growing concern about the impact of this significant change in land use on the quality and quantity of water supplies.

The smaller high‐quality upland sources, which historically have minimal treatment, are those most at risk from changes as a result of forestry activity. Problems caused by a reduction in yield at some sources in the Region are discussed. A number of afforested water‐supply catchments have been monitored since 1984 with the aim of identifying trends in water quality, and the results indicate increases in colour, turbidity, acidity and aluminium in supplies after activities such as access road construction, ploughing and draining. Evidence is presented of the continued leaching of phosphate more than six years after the application of fertilizer.

To enable improved advance consultation and planning to protect public water supplies, there is a requirement to be able to indicate the likely sensitivity of individual supplies to the various effects of afforestation.

The Region is committed to a substantial ten‐year capital expenditure programme to upgrade water‐treatment works to comply with the recent European Community (EC) water‐supply standards imposed in 1985. Any significant long‐term changes in water quality associated with forestry activity will make this programme more costly to achieve.
River‐Channel Changes in England and Wales
Authors: HOOKE J. M. , REDMOND CLAIRE E.
Published: July 2007

An investigation of the literature on river‐channel changes in the UK reveals that the rate and extent of changes is much higher than was previously thought. In order to assess how widespread these changes are, and whether the rates and types of changes are typical, an historical survey has been carried out of the streams which drain the upland areas of England and Wales. This survey involved the comparison of Ordnance Survey 1:10,560 maps from approximately 1870 and 1950, and revealed that almost 35% of the rivers draining upland England have shown some pattern instability during this period.

Great variety exists both in the types of channel planform changes and their extent: several rivers possess short isolated reaches of change separated by stable sections. This suggests the operation of thresholds of channel stability, and further research aims to identify these in terms of specific factors and conditions.
A Water Quality Index for River Management
Authors: HOUSE MARGARET A.
Published: July 2007

The theoretical basis underlying the development of a new series of water quality indices is outlined. The main features of their development are the incorporation of legally adopted water quality standards and criteria and the inclusion of information on potential water use and toxic determinands directly within their structural format. Thus an indication of a change in the economic potential of a river through a gradual change in water quality (and hence water use) can be obtained.

The General Water Quality Index (WQI) has been applied to all the data for an annual or longer time series as a means of detecting cycles and trends in river water quality. An examination of the lowest determinand ratings for each data set highlights the specific determinand(s) responsible for these deteriorations. A 5 percentile WQI score has been calculated for the time series of data and 90 per cent upper and lower confidence limits calculated around this score.

The results of these applications indicate the ability of the index accurately to reflect both changes in water quality and potential water use.
Trade Effluent Control: Prospects for the 1990s
Authors: MARTINDALE R. R. , LANE G.
Published: July 2007

The proposed privatization of the ten regional water authorities together with the accompanying reorganization of water pollution control responsibilities between the new National Rivers Authority and Her Majesty's Pollution Inspectorate, as well as the ever tightening environmental standards for the aquatic environment emanating from Brussels and from general environmental pressures, means that dischargers of industrial effluents can expect major changes both in the cost of disposing of their effluents and in terms of the legislative controls which will restrict their content.

The paper examines the various factors which will influence the management of trade effluents in the 1990s and endeavours to give some indication of what the future holds both in terms of disposal costs and environmental regulation from the point of view of the discharger.
An Investigation into the Performance Characteristics of Boundary Boxes Subjected to Vertical Loading
Authors: DICKENS J. G. , MORTIMER G. H.
Published: July 2007

This paper presents the results of a series of load tests carried out on a variety of designs of boundary boxes which are intended for use as stopcock/water meter chanbers at domestic properties. A description is given of a test which has been developed at Loughborough University to measure the performance, under load, of the complete boundary‐box units in simulated site conditions. Three broad classifications of different design types are identified, namely rigid, flexible and sliding; and the load displacement characteristics of each type are presented and discussed. The effects of rate of loading and different backfill conditions are considered, and conclusions are drawn on suitable performance specifications under load.
The Role of Asset Management
Authors: BRITTON R. J. , RUMSEY P. B.
Published: July 2007

The paper describes the role of asset management in the UK water industry. An asset management plan is directed to capital works and other expenditure associated with maintaining the condition and performance of the utility's assets. The six parts of an asset management plan are described, together with an outline of the broad considerations necessary in the preparation of such a plan. This leads to a description of the role of asset management and a consideration of the impact on the utility organization.

It is concluded that asset management planning provides an effective method of determining long‐term investment needs and is of major benefit in the day‐to‐day management of a utility.
Hydrological Information Transfer Using HOMS
Authors: OLIVER H. R. , MILLER J. B.
Published: July 2007

The Hydrological Operational Multipurpose Subprogramme (HOMS) scheme of the World Meteorological Organization (WMO) consists of an international network for the transfer of packages of proven hydrological know‐how, with particular emphasis on helping developing countries. More than one hundred HOMS centres worldwide produce and supply information components and handle requests for components for use in their own countries. Details are presented of the organization and operation of HOMS, together with example case studies to illustrate its successful use.
Odour Control for the 1990s ‐ Hit or Miss?
Authors: TOOGOOD S. J.
Published: July 2007

The growing importance of odour control and the failure of a high proportion of abatement schemes are discussed. A strategy for dealing with nuisance is presented, laying emphasis on a fully integrated approach, involving covering, ventilation design, and odour treatment. Some of the options for treatment are compared.
Low Flow Estimation Based on River Recession Rate
Authors: CURRAN J. C.
Published: July 2007

Successful pollution control in a river is fundamentally based on a reliable knowledge of the flow available for dilution of the polluting discharges. Often there may be no available gauging records within a catchment or subcatchment, and it may be necessary to resort to an estimation procedure. It is shown that low flow can be predicted through consideration of (a) a recession period and its relation to rainfall, and (b) a recession rate and its relation to local soil types. Statistical analysis provides an indication of the accuracy of prediction.
Health Effects of Working in Compressed Air
Authors: HEMPLEMAN H. V. , McCALLUM R. I. , EVANS A. , JARDINE F. M.
Published: July 2007

For more than 50 years, civil engineers, scientists and the medical profession have collaborated to reduce the occupational health risks of working in compressed air. Under the auspices of the Medical Research Council, the Health and Safety Executive and, through the Construction Industry Research and Information Association (CIRIA) of the civil‐engineering industry, the data of the Decompression Sickness Central Registry of exposure and medical records are being analysed in order to identify healthier working practices and disciplines.
Microbiological and Trihalomethane Responses to Booster Chlorination
Authors: GIBBS R. A. , SCUTT J. E. , CROLL B. T.
Published: July 2007

Two zones of a water distribution supply area receiving treated surface water were used to study the effect of booster chlorination on bacterial regrowth. In the first year of the study general patterns of bacterial regrowth were observed, and in the second year one of the areas was booster chlorinated at the outlet from a surface reservoir. In both years of the study the heterotrophic plate counts showed a seasonal pattern. In the second year there was a large increase in plate counts from mid‐July to October in both of the study areas. During this period, booster chlorination was unable to prevent bacterial regrowth. The addition of chlorine to produce an initial free chlorine residual of 0.5 mg/1 resulted in a reduction in bacterial numbers, but with further retention in the distribution system bacterial regrowth occurred. There was little increase in the trihalomethane (THM) concentration following booster chlorination, but booster chlorination appeared to increase the assimilable organic carbon concentration.
The Socio‐Economic Impact of Improved Wells in Rural Sierra Leone
Authors: BAH O. M. , HOLLIS G. E. , RICHARDS. P.
Published: July 2007

The construction of improved wells with the participation of the local communities in rural Sierra Leone is examined. Two chiefdoms were surveyed with four sample villages being examined in depth through questionnaires, interviews, participant observation and quantitative monitoring of water abstraction.

Only 36% of the improved wells were operational in the dry season, and these made a modest contribution to water demand in the villages. Half the water consumption was on the remote farms where improved wells played a negligible role. Social and cultural difficulties with the wells were as important as their dry season desiccation in explaining the minimal impact of the well‐digging scheme.

Post‐project evaluation by a multi‐disciplinary team could provide invaluable inputs to the planning of an ongoing programme.
Blackburn Meadows Sewage‐Treatment Works: Sludge Incineration into the 1990s
Authors: TOLAN D. J. , BENNETT D. , KWIECINSKI J. V.
Published: July 2007

The new sludge‐dewatering and fluidized‐bed incineration plant at Blackburn Meadows sewage‐treatment works, Sheffield, was commissioned in March 1990, replacing the former aged and costly filter presshouse and multiple‐hearth incineration plant. The plant was the second in a ‘new generation’of integrated‐design sewage‐sludge incinerators commissioned by Yorkshire Water to meet the Company's operational, economic and environmental needs for sludge treatment and disposal at the Blackburn Meadows works.

This paper details the work undertaken on the project from historical development and contractual issues to plant commissioning, reviewing the first six months’operating experience.
Public Perception of River‐Corridor Management
Authors: HOUSE MARGARET A. , SANGSTER E. K.
Published: July 2007

Research into the public's perception of water and river‐corridor quality has been undertaken to assess the importance of these aspects to the public's selection of sites for use in recreation.

Preliminary results from two on‐site questionnaire surveys involving a number of river user groups suggested that:

Whilst there was a strong association between perceived water quality and the presence/absence of individual water‐quality variables, the presence of indicators of ‘good’water quality were less likely to influence perceived water quality than the presence of indicators of ‘bad’water quality;

There was an overwhelming desire for trees and a strong preference for vegetational diversity within the public's perceived ideal river corridor setting; and

An equally strong preference for mature, sinuous rivers with natural channels and banks.

These results suggest that there is a close relationship between the type of riverscape preferred by the public in their use of rivers for recreation and amenity, and that desired by conservationists.
Frankley Water‐Treatment Works Redevelopment: Pilot‐Scale Studies
Authors: SCHOFIELD T. , PERKINS R. , SIMMS J. S.
Published: July 2007

The redevelopment of Frankley water‐treatment works (maximum flow 450 Ml/d), which supplies soft upland‐derived water to the Birmingham area, will enable iron, manganese, colour, turbidity and natural aluminium levels to be significantly reduced below the EC drinking water quality Directive.

This paper describes the pilot studies which led to the decision to build what is presently believed to be the largest dissolved‐air flotation plant in the world.

The studies demonstrated, amongst other things, the effectiveness of ferric sulphate for treating coloured upland waters; the viability of stablization using carbon dioxide and lime to prevent pH variation in the distribution system; that a membrane press was the most appropriate dewatering process, and that the treated water would reduce the particulate lead concentrations in properties containing lead service pipes.

Costing £0.5 million and equating to approximately 1% of redevelopment cost, the pilot study was considered to be excellent value.
A Pilot UK Evaluation of a Rapid Defined Substrate Method for Enumeration of Total Coliforms and Escherichia coli in Water
Authors: ARGENT V. A. , BOOTH N. E. , FLYNN T. , JONES C. E. , KENT J. , MAN B. N. , REED R. H.
Published: July 2007

A simple rapid method for determining total coliforms and Escherichia coli in drinking water was evaluated in a preliminary pilot‐scale study at three independent laboratories by comparison with the standard membrane filtration technique. No significant difference was found between the two methods.

The method is based on defined substrate technology. It gives confirmed results within 24 h and requires only limited equipment. It was considered particularly suitable for weekend and emergency use and for on‐site testing at remote sampling points.
Water Quality Implications of an Observed Trend of Rainfall and Runoff
Authors: CURRAN J. C. , ROBERTSON M.
Published: July 2007

The catchment of the upper Clyde estuary has experienced a significant and steady increase of rainfall over the past twenty years. The corresponding increase of runoff has had a positive impact on the water quality both of the individual rivers and of the estuary. Examples are provided to show that approximately one third of some observed improvements are attributable to the additional dilution. It is emphasized that comparisons of water quality data, either by region or by period, should allow for climate variability.
New Treatment Processes for Pesticides and Chlorinated Organics Control in Drinking Water
Authors: FOSTER D. M. , RACHWAL A. J. , WHITE S. L.
Published: July 2007

Sources of pesticides and chlorinated organic compounds potentially found in water sources are reviewed. International and UK drinking water standards for these compounds are discussed and compared with concentrations found in ground and surface waters derived from lowland agricultural and urban areas.

Water soluble herbicides including triazines, phenylamides (urons) and chlorophenoxy acids are the most commonly reported types of pesticide compounds found above 0.1 μg/l in water sources. The more toxic, and less water soluble, organo‐chlorine and organophosphorus pesticides are rarely reported.

Chlorinated organic solvents are reported as contaminants of some groundwaters. Disinfection by‐products, in particular trihalomethanes, formed during the chlorination of waters containing natural organics, are widely reported, sometimes at concentrations above current UK standards.

The effects of conventional water‐treatment processes on the concentrations of these organic compounds are discussed. Additional water‐treatment processes, designed specifically for trace organic micropollutant removal, are identified and reviewed. Ozonation, activated‐carbon adsorption and air stripping are acknowledged as appropriate advanced water‐treatment process solutions. Developments in novel technologies include organics destruction via advanced oxidation processes, biological processes, membrane technology and novel adsorbents.

Thames Water Plc is contributing to research in this area, investing over £5 million in pilot‐ and large‐scale trials prior to a £200‐£300 million capital investment programme in advanced water treatment in the 1990s.
Drainage of a Mountain Road in Nepal
Authors: WILLIAMS L. G.
Published: July 2007

The paper describes the contribution made by the drainage engineer to the design of the Arun Road situated in the Middle Himalaya of Eastern Nepal. A description is given of the way in which a limited amount of hydrometric and meteorological data was synthesized into a relatively simple hydrological model which could be used for drainage design. The mountains crossed by the road are environmentally fragile and populated by subsistence farmers, and this demanded that special care be taken in the hydraulic design of bridges, culverts, and associated works in order to minimize the adverse consequences of the road construction.
Hydrology of Pesticides in a Chalk Catchment: Surface Waters
Authors: GOMME J. W. , SHURVELL S. , HENNINGS S. M. , CLARK L.
Published: July 2007

In an extensive study of pesticides in a Chalk catchment, twenty pesticides were selected for study; and this paper reports the findings of an eighteen‐month programme of river and rainwater sampling. The results of periodic samples and an intensive river monitoring programme over the duration of a flood event are described.

Both rain and river water within the catchment were found to contain significant numbers of pesticides at varying concentrations. The paper describes the values and temporal variations which were discovered. Higher concentrations and greater numbers of pesticides appeared to be brought down by floods and high river flows; however, even during low flows, some pesticides were persistently found in the river.
Environmental Implications of Treatment of Coastal Sewage Discharges
Authors: GAY J. , WEBSTER R. , ROBERTS D. , TRETT M.
Published: July 2007

The environmental implications of implementing the requirement for treatment of coastal sewage prior to discharge, which were put forward in an EC draft Directive on municipal waste‐water treatment, are examined. In order to establish the current situation, the results of a national survey of coastal and estuarine sewage discharges are presented. A review of the impact of sewage discharges on the marine environment is presented in conjunction with an assessment of the impact of sewage‐treatment processes on the land and in the air. These aspects are integrated into overall conclusions about net environmental impact. Finally, a decision‐tree approach to the assignment of priority to additional action required at individual locations is developed.
Disposal of Petrochemical Plant Effluents by Shell UK at Stanlow
Authors: SPARSHOTT M. B.
Published: July 2007

The co‐disposal of petrochemical plant wastewaters with domestic and industrial effluent is described, with emphasis on pretreatment and effluent management aspects, as conducted by the effluent producer. A brief history of the specific development of co‐disposal of Shell Chemicals (Stanlow manufacturing complex) effluent is given, leading to the recently completed investment of £5.2 million in improved pretreatment facilities, allowing full and failure‐free advantage to be taken of the sewage‐treatment facilities installed by North West Water at Ellesmere Port for the disposal of Shell Chemicals effluent, at a cost of £7.5 million, and commissioned in 1985. Effluent quality problems, and the establishment of dedicated effluent monitoring routines, are described together with the installation of quality and volume monitoring of individual effluents, leading to both processing cost allocation and management accountability. A description is given of the original and redeveloped pretreatment unit for neutralization, de‐oiling and clarification of the effluent. Brief reference is made to liaison arrangements between Shell and North West Water and to the training of staff in effluent management.
Genetic Engineering for Wastewater Treatment
Authors: McCLURE N. C. , FRY J. C. , WEIGHTMAN A. J.
Published: July 2007

This paper discusses the application of genetic engineering to improved wastewater treatment, with particular emphasis on the enhanced breakdown of recalcitrant pollutants. The genetic construction of bacterial strains capable of degrading problem compounds, especially chlorinated aromatics, is described. In addition, the problems affecting the functioning of these ‘genetically engineered’laboratory strains in situ is addressed. The results of recent studies into the survival and function of both ‘natural’and ‘genetically engineered’bacteria inoculated into laboratory‐scale activated‐sludge units are presented. These results indicate that several factors may affect the expression of catabolic activities in situ, and that those bacteria which are well adapted to growth and survival in target ecosystems are more likely to be successful inoculants than are laboratory strains.
Protecting Water Resources from the Effects of Landfill Sites: Foxhall Landfill Site
Authors: PALMER C. , YOUNG P. J.
Published: July 2007

This paper describes the work carried out to protect both ground and surface waters close to the Suffolk County Council Foxhall landfill sites. Monitoring of groundwater showed that a deterioration was occurring, likely to impact adversely on water quality in the adjacent stream. The National Rivers Authority expressed their concern, and measures have been introduced to eliminate this pollution risk. Contaminated groundwaters flowing towards a local watercourse are intercepted by a ‘Trammel’type geotextile cut‐off drain and flow to a central collection sump. Automatic monitoring of contaminant levels at this point controls the treatment and disposal options. Where quality is unacceptable for discharge to the local watercourse, the intercepted groundwaters are treated by irrigation onto the capped surface of a restored landfill. If quality remains unacceptable for discharge, further irrigation treatment or discharge to a percolation area utilizing aquifer attenuation properties is possible.
Aspects of Eutrophication in the Venice Lagoon
Authors: DAMIANI A.
Published: July 2007

The Venice lagoon has been the subject of many studies during recent years directed towards the assessment of its ecosystem and to its environmental restoration, as well as to finding a solution to the problem of the high water condition which affects the historical city centre. This paper presents input and output data of the ecosystem and the present situation concering eutrophication and the pollution of the environment.

The analysis of nutrients shows that the biological processes do not occur at the same rate. In fact the variation of phosphate concentrations is wider than that of nitrogen because of the greater biological reactivity of phosphate. The analyses show that it is impossible to determine the dominant eutrophication element in the lagoon, therefore its environmental protection needs action to reduce both nitrogen and phosphorus input.
Some Environmental Aspects of the Management of Water Supplies for the Region of Madrid
Authors: CUBILLO F.
Published: July 2007

In the management of water resources it is essential to ensure a pure, adequate and constant supply to consumers. In recent years, however, increasing attention has been directed to ensuring that water resources have no detrimental effects on the environment. The avoidance of adverse environmental effects becomes more difficult during the management of established systems; some, such as that of Madrid, were designed with old environmental requirements and are often complex in nature.

This paper analyses the effects of such a system upon the aquatic ecosystems and on the supply of drinking water.
Environmental Auditing in the Public Sector: The Lancashire Experience
Authors: TAYLOR D.
Published: July 2007

Lancashire County Council was one of the first local authorities in the UK to audit the environment of its locality and to review the environmental impact of its operations. The paper outlines the reasons for this and how it has been put into effect. The management structure devised to carry forward and coordinate the initiative is outlined first, encompassing elements internal to the County Council and the establishment of a Lancashire Environment Forum. Secondly, the preparation of a county‐wide state‐of‐the‐environment audit is described, together with the implementation stages which have ensued. The paper is completed by an account of the County Council's internal review of the impact of its own activities.
The Impact of Electricity at Work Regulations on the Operation of a Water Company
Authors: STOKER J. M.
Published: July 2007

Since 1 April 1990, the Electricity at Work Regulations 1989 have placed legal requirements on employers, employees and the self‐employed to take precautions against the risk of death or injury from electricity in work activities. This paper (a) examines the requirements, (b) reports on an initiative by the Lee Valley Water Company, and (c) proposes a management strategy for an organization to comply with the legislation.
Middleton‐in‐Teesdale Supply Area: Improvements to the Supply Network
Authors: ANDREWS T. R.
Published: July 2007

The paper covers the design of improvements to a water distribution system serving a rural area to eliminate low chlorine residuals and to cater for large potential increases in demand from an agricultural estate. A model of the existing system was analysed at current and increased demands to identify weaknesses in the system. The model was altered by the addition of pumping mains, two storage reservoirs at new locations, and the strengthening of distribution mains to provide a solution to meet the client's requirements.

The location and size of the proposed reservoirs were optimized with respect to the construction costs of the reservoirs, pumping and distribution pipelines, and pump running costs.

Areas were zoned to provide better strategic storage, whilst also reducing retention times, thus eliminating the problems of low chlorine residuals.
Wellhead Protection Zones in Germany: Delineation, Research and Management
Authors: SCHLEYER R. , MILDE G. , MILDE KARIN
Published: July 2007

In Germany there is much legislation to guarantee adequate protection of groundwater quality and quantity. The main objective of the legislation is to maintain the natural high quality of groundwater. The most important Act in this context is the Water Resources Policy Act.

One aspect of German groundwater protection is the possibility to delineate up to four wellhead protection zones in the recharge area of a drinking‐water well. The time‐distance integrated protection zone concept, with bans and limitations on use increasing towards the well, was developed in the 1930s. It has guaranteed for decades a safe drinking water supply from the point of view of quality. However, recent scientific investigations have shown gaps especially with regard to (a) the importance of the 50‐days line, (b) the behaviour of micro‐organisms and (c) the mobility and persistence of man‐made pollutants.
Leachate Collection, Treatment and Disposal
Authors: ROBINSON H. D. , BARR M. J. , LAST S. D.
Published: July 2007

As landfills become larger, the enormous quantities of putrescible wastes which they contain have increased the potential to generate highly polluting leachates as they decompose anaerobically over many years. If severe environmental impacts are to be avoided, operators must control these liquors: many landfill proposals stand or fall on the ability of the operator to demonstrate that leachate can be collected, managed and disposed of in an environmentally acceptable manner. During the early years of tipping in containment cells, high BOD and COD values (to 50 000 mg/l or more) are measured, with very high ammonia concentrations (to more than 1000 mg/l as N) persisting for many years.

The authors have been involved with the full‐scale on‐site treatment of leachates to high standards in automated aerated lagoon plants since the early 1980s. The first plant was constructed in 1982, and a further seven have since been built at landfills throughout the UK, with many more at various stages of design and construction – both in the UK and overseas.

This paper describes detailed operational experiences from several of these landfill sites, with particular emphasis on the reduction of ammonia concentrations to low values. The use of reed‐bed treatment schemes as effluent polishing facilities is also discussed.
Reservoir Sedimentation and Colour Problems in Southern Pennine Reservoirs
Authors: BUTCHER D. P. , CLAYDON J. , LABADZ J. C. , PATTINSON V. A. , POTTER A. W. R. , WHITE P.
Published: July 2007

A study of two major environmental issues in upland water management is presented. Discolouration and reservoir sedimentation are seen to affect water managers on different timescales and to different degrees. Rates of reservoir sedimentation, adjusted for empirically derived trap efficiency, are measured and found to be higher than previously believed. A link between sediments found within the reservoir basin and the generation of colour is described.
Environmental Auditing and Management in Local Government
Authors: JACOBS M.
Published: July 2007

New holistic approaches to environmental management by local authorities are described. Two kinds of audit, the state of the environment report and the internal audit, are defined. State of the environment reports are assessments of the condition of the local environment, generally based on existing data. They provide information about the environment to the general public and enable councils to determine environmental strategy priorities. They are giving local authorities a new environmental stewardship function. An internal audit is an assessment not only of the authority's impacts as a producer but of its environmental interactions as a regulator, influencer and manager of the environment. For some councils, auditing is becoming a continuous process through which environmental factors can be taken into account as a routine part of policy making and implementation.

Both kinds of audit are changing the relationships of local authorities, reducing internal departmentalism and leading to wider consultation and partnership with local communities.
An Incidence of Massive Biofouling of Sand Filters: A Biochemical Detective Story
Authors: G. WALTON N. R.
Published: July 2007

A serious biofouling incident at an overseas water treatment plant is described, together with the background information and recorded operational data which provided the subtle, but unheeded, physicochemical clues to the developing biological problem. At the time, however, it was not realised just what was causing the serious filtration problems and even upon discovery of the filter‐clogging algae it was not immediately obvious what had caused their appearance, growth and subsequent rapid death within a sealed groundwater system. However, piecing together the story with hindsight from all the available clues has proved to be a fascinating and illuminating piece of biochemical detective work with unexpected conclusions which have wider ramifications within the water industry.
Atmospheric Inputs to the North Sea and Coastal Waters
Authors: Van JAARSVELD J. A.
Published: July 2007

The importance of the atmospheric pathway to the pollution of surface waters, and in particular the North Sea, has been confirmed by studies carried out during the last decacde. However, there are still large uncertainties associated, not only with the quantities of pollutants measured, but also with the methodologies followed to obtain estimates for large areas such as the North Sea. A large part of the uncertainties can be attributed to the lack of representative and reliable measurements at open sea. This paper discusses methodologies which have been used and gives an overview of results reported so far. Some model results on the deposition distribution over the North Sea of nitrogen and lead are presented, and the paper considers the research needs to improve the understanding of air–sea exchange processes and the research which is currently being carried out.
Environmental Auditing Practice
Authors: CARGILL J. D.
Published: July 2007

The various types of environmental audits are discussed, and the steps to be taken when carrying out pre‐acquisition environmental audits are outlined. A comparison is made with due diligence audits and the proposed Eco‐audit.
Contrasting Problems of Implementing European Community Water Protection Zone Policies in Ireland and the UK
Authors: L. FOSTER I. D. , THORN R. H.
Published: July 2007

The 1991 EC nitrate Directive has significant implications for agricultural and pollution prevention enforcement agencies throughout the European Community. Contrasting physical backgrounds, water supply sources and leaching rates, together with pre‐existing nationally‐based pollution control policies, means that implementing the Directive will cause different problems for member states. This paper examines the contrasting physical and legislative backgrounds in Ireland and the UK and looks at some of the problems in implementing EC policy.
Water Treatment in Europe and North America
Authors: CROWLEY F. W. , PACKHAM R. F.
Published: July 2007

Significant differences in the way that basic water‐treatment processes are engineered in Europe and the US have been apparent for nearly 50 years. In the US, standardized and rather conservative treatment works have been in wide use for decades, whereas in Europe there is a wide range of designs, many having important advantages in terms of cost and efficiency. It is significant that in Europe, specialist treatment plant contractors make a major contribution to the development of new designs, whereas in the US this is mainly the responsibility of consultants. Drinking water quality standards are becoming more complex, and it is considered that the technologies used on the two continents for dealing with the newer contaminants will be similar. The system used in the US for developing water quality regulations, which is scientifically based and involves considerable consultation with the water industry, has major advantages over that used in the European Community.
Satisfying the Water Supply Demand of the Channel Tunnel
Authors: CROSS G. A. , TURNER A. G.
Published: July 2007

When Europe's largest civil‐engineering construction site, the Channel Tunnel, requested a guaranteed source of water during 1988, the Folkestone District Water Company was experiencing the first signs of the drought conditions which were to prevail for the next three years. Whilst infrastructure changes allowed for supplies to be made available to the Channel Tunnel contractors, the increasing reduction of resources meant that an alternative supply of water was required.

The solution to the problem was to utilize desalination by reverse osmosis of sea water taken from the English Channel. The process design and operation of this most arduous of feed water is discussed, demonstrating the successful application of this technology.
Upgrading Miskolc Sewage‐Treatment Works, Hungary
Authors: DAWSON J. B. , SUMMERFIELD M. T. , HALL J. E.
Published: July 2007

Traditionally, sewage‐works design in Hungary has been based on rigid national standards with little consideration being given to the requirements of individual situations. This has resulted in plants that performed poorly and were expensive to construct and operate.

The paper describes measures to improve the environment by upgrading Miskolc sewage‐treatment works, and the conflict between the cost of those facilities, and the ability to pay against a background of changing economic conditions.
Protection of Buildings from Hazardous Gases
Authors: TOWLER PHILIPPA A. , YOUNG P. J.
Published: July 2007

The stringency of building protection measures which are required to mitigate the accumulation of the hazardous gases carbon dioxide, methane and radon is a reflection of the perceived risk. About 2500 deaths per year in the UK are attributed to radon, while incidents of deaths involving methane and carbon dioxide derived from landfills and mine gas average less than one per year. Potentially about 5% of all UK premises are at risk from contamination by these hazardous gases. This compares with a lower proportion of buildings affected by forms of previously contaminative use, which are to be collated into a register of potentially contaminated land when s. 143 of the Enviromental Protection Act 1990 is implemented. The potential hazard, migration, principles of control, and design of building protection measures, are reviewed for all three gases.
National Rivers Authority National Strategy and Planning for the Future
Authors: SWINNERTON C. J. , F. SHERRIFF J. D.
Published: July 2007

The protracted drought from 1988 to 1992 has focused attention upon the availability of water sources in England and Wales. The drought was most severe in the east and south‐east parts of England, which also coincides with the areas having (a) the least available water resources, (b) the greatest forecast increase in demand, and (c) the majority of low‐flow problems due to excessive authorized abstraction. Even with increasing attention being paid to demand management, there is a need to develop further water‐resource schemes. Once local options have been developed it is likely that inter‐basin transfers will be required.
Water Resources Development: A Balanced Approach
Authors: McINTOSH P. T.
Published: July 2007

Customers, the public generally, the water industry, its regulators and the government are aware that water can be a scarce and costly product. Resource planning and development must increasingly be viewed as a combined package of water efficiency in (a) use, (b) metering and tariff policy, (c) leakage reduction, and (d) physical schemes.

Droughts, fears over possible climate change, concerns about resources and the environment, a greater awareness of the role and costs of the water industry and statements by the Department of the Environment, the Office of Water Services, and the National Rivers Authority have added weight to this sensible shift in emphasis.

However, society needs reliable water supplies and cannot completely rely upon the uncertain impact that demand side‐measures may bring about – nor, even where achieved and cost‐effective, on the important savings in losses. New resource schemes can take many years to implement. Therefore, in order to ensure adequate and reliable supplies, plans for new schemes must be brought to a state of readiness, and, in many cases, implemented.
Effluent and River Quality: How the UK Compares with Other EC Countries
Authors: Mance G.
Published: July 2007

This paper examines the limited information on the actual performance of sewage‐treatment works as reflected in discharge quality from European Community member states. The control regimes for such effluents as well as the proportion of population served by sewerage and various levels of sewage treatment are contrasted between member states. Standards for river water quality and an assessment of actual river quality are then contrasted. These suggest that in the UK, river quality is considerably better overall than in other member states.