bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Fog Collection in Jordan
Authors: Al‐Jayyousi O. R. , Mohsen M. S.
Published: July 2007

Water‐supply augmentation along with supply and demand management in Jordan have been considered to meet the water demand. This paper evaluates the feasibility of fog collection in Jordan using various low‐cost materials. Experiments were conducted using four standard fog collectors with different local materials. An analysis of fog‐collection effectiveness was carried out and compared with international experience, and showed that local sacking material was the most effective. Recommendations for applying this technique are outlined.
The Role of Geographical Information Systems in Urban Hydrological Modelling
Authors: Goonetilleke A. , Jenkins G. A.
Published: July 2007

‘Geographical information systems’(GIS) technology holds considerable benefits to urban hydrology because of the spatial nature of catchment analysis. The availability of a spatio‐temporal database of catchment characteristics can eliminate the adoption of simplifying assumptions, which reduce the quality of a research study. This research study was undertaken to demonstrate the need for accurate spatial and temporal accounting of land‐use in an urbanizing catchment. The definition of the extent of GIS use, the approach to its integration into a study, and spatial database development, are crucial for eventual success.
Small‐Scale Hydro‐Power in the UK
Authors: Kirk T.
Published: July 2007

Small hydro‐power technology is well established in the UK. A relatively recent renewal of interest in the development of mini hydro‐electric projects may be attributed in part to the privatization of the electricity supply industry, various changes in legislation, and the provision of Government grant funding.

With particular reference to potential applications in the water‐supply industry, this paper describes (a) considerations dictating site identification, (b) the establishment of potential power and energy outputs, (c) the selection and arrangement of plant, and (d) the connection of the generating sets to the electrical system. Typical plant and project costs, together with aspects of economic viability, are outlined.
Evaluating Water‐Importation Options in Jordan: Opportunities and Constraints
Authors: Hussein I. , Al‐Jayyousi O.
Published: July 2007

The future management and development of water in Jordan presents a challenge for decision makers and water‐sector planners. The gap between the available water supply and demand has opened in the agricultural and domestic sectors and is likely to widen unless adequate measures are taken. Water importation for Jordan is a sound future option in water‐resources planning. The options are (a) the Peace pipeline from Turkey, (b) the Litani River pipeline, (c) the Euphrates River pipeline, and (d) a pipeline from Egypt. An analysis and evaluation of the options reveals that the most viable scheme is the Litani River, followed by the Peace pipeline from Turkey.
Design, Construction and Performance of a Full‐Scale Compost Wetland for Mine‐Spoil Drainage Treatment at Quaking Houses
Authors: Jarvis A. P. , Younger P. L.
Published: July 2007

Acidic spoil‐heap drainage, containing elevated concentrations of iron, aluminium and manganese, has been polluting the Stanley Burn in County Durham for nearly two decades. Following the success of a pilot‐scale wetland (the first application of its kind in Europe), a full‐scale wetland was installed. Waste manures and composts have been used as the main substrate which is contained within embankments constructed from compacted pulverized fuel ash. The constructed wetland, which cost less than £20000 to build, has consistently reduced iron and aluminium concentrations and has markedly lowered the acidity of the drainage. A third phase of activities at the site aims to identify and eliminate pollutant‐release ‘hot spots’ within the spoil.
The Danube Programme: The Challenge of International River‐Basin Management
Authors: West E.
Published: July 2007

This paper highlights the key issues which affected the design and implementation of water policy within the first phase of the Environmental Programme for the Danube River Basin. The programme represents one of several regional environmental initiatives in Eastern Europe which were designed to control pollution through the coordinated actions of national governments, international organizations, international financial institutions and non‐governmental organizations.

The paper identifies three key controversial findings. Firstly, although the programme has been a valuable tool for the skills and technology transfer which are necessary to enable the Danube states to control water pollution, it has failed to generate the anticipated levels of capital investment or establish itself as a cornerstone of Danube basin management. Secondly, the policy process has been beset by political, economic, social and historical conflicts and power struggles between the participating parties. Thirdly, valuable lessons for the strategic and sustainable management of international river basins can be learned from the operational experiences of the Danube programme.
Derivation of an 88‐Year Inflow Record for Talla Reservoir, Scotland, with Special Reference to Low Flows
Authors: Black A. R. , Cranston M. D.
Published: July 2007

A new synthetic inflow record for Talla Reservoir is derived from reservoir log data for the period 1907–94. The paper describes (i) the procedures which were adopted for the derivation, based upon a reservoir water balance, and (ii) the changes in contributing area. For the years since construction of an upstream reservoir in 1968, the summer analysis draws on data from a neighbouring catchment in order to provide analysis of a more homogeneous time series. The paper also discusses the possibility of undertaking similar work for other reservoirs, as a means of improving the knowledge of the past variability of UK water resources.
Ozone Treatment of Sewage Works' Final Effluent
Authors: Paraskeva P. , Lambert S. D. , Graham N. J. D.
Published: July 2007

This paper describes a laboratory‐based study which was designed to investigate (a) the changes in selected physico‐chemical properties of a sewage‐works' final effluent after ozonation, and (b) the effect of ozone on the concentration of organic halides and effluent toxicity and mutagenicity. Different conditions were studied involving the application of ozone concentrations up to 13.5% w/w and the ozonation of the effluent under both constant and variable ozonation rates.
The Benefits of Flood Warnings: Real But Elusive, and Politically Significant
Authors: Penning‐Rowsell E. C. , Tunstall S. M. , Tapsell S. M. , Parker D. J.
Published: July 2007

Flood‐warning systems need to be seen as providing (a) forecasts of floods, (b) warnings to those at risk, and (c) in‐between arrangements for disseminating warning messages to those who need the information as a basis for their response. This ‘whole‐system’approach reveals that warning dissemination and public response are weak links in the communication chain, and that the public remains dissatisfied with the service which should be seamless and reflect an integrated approach. Research on several aspects of this system reveals significant and continuing problems of low performance, leading to the question as to whether the present institutional arrangements in the UK for flood warning are satisfactory.
Infiltration Systems: A Sustainable Source‐Control Option for Urban Stormwater Quality Management?
Authors: Ellis J. B.
Published: July 2007

Source control is regarded as a key principle in supporting concepts of sustainable management and integrated pollution control for diffuse non‐point stormwater runoff, with infiltration procedures being a prime component of such source‐control systems. The potential conflicts between the benefits of groundwater recharge and the risks to long‐term groundwater quality uncertainties associated with infiltration disposal are considered. The long‐term performance of a number of infiltration systems is reported in terms of their pollutant removal efficiencies, and the utility of an infiltration acceptability matrix approach is reviewed.
Gasification As An Innovative Method of Sewage‐Sludge Disposal
Authors: Hamilton C. J.
Published: July 2007

There is a significant amount of energy in the carbonaceous component of sewage sludge. Effective use can be made of this energy through conversion to the gaseous state followed by gas cleaning and subsequent firing of a gas turbine.

This paper (a) compares the technology for the gasification of dried sewage sludge, noting the advantages in favour of fuelling a gas turbine, (b) reviews the significance of the individual components in sewage sludge, and (c) provides a brief introduction to a demonstration project which was embarked upon by Northumbrian Water in conjunction with Lurgi, with the financial support of an ECU Thermie Grant.
Does Groundwater Abstraction Cause Degradation of Rivers and Wetlands?
Authors: Acreman M. C. , Adams B. , Birchall P. , Connorton B.
Published: July 2007

There is a widely held belief that, over the last few decades, many rivers and wetlands have been significantly degraded. Clearly, groundwater abstraction has had a detrimental effect. However, other pressures such as channelisation, sedimentation, reduced rainfall, poor site management or land‐use change can be contributing factors. Various policy responses are reviewed and some examples are given. It is concluded that, whilst groundwater abstraction does cause river and wetland degradation, the degree of degradation often depends upon the individual perspective; therefore a rigorous approach is required in quantifying such degradation and its actual causes, beginning with the establishment of clear objectives and the collection of appropriate data.
Investigation of Rosette Corrosion in Copper Hot‐Water Cylinders
Authors: Oliphant R. J.
Published: July 2007

This paper reports upon the premature failure of copper hot‐water cylinders fitted with aluminium protector rods, so‐called ‘Rosette’corrosion. The purpose of the protector rod is to prevent Type 1 copper pitting and has been used successfully for nearly thirty years. The change in composition of waters in contact with cylinders fitted with protector rods, which was monitored over a 12‐month period, established that various species which were aggressive to copper, i.e. nitrite, ammonia and possibly sulphide, were being produced. The potential mechanism for the creation of these ions, and hence the water compositions which are likely to promote Rosette corrosion, are discussed. The change in cylinder design, which is being adopted by manufacturers to overcome this problem in the future, is outlined.
Conservation Objectives and Targets for Freshwater Sites
Authors: Brown A. E.
Published: July 2007

Conservation objectives and targets, which play a vital role in conserving freshwater biodiversity, have been developed on many different scales according to the roles and responsibilities of the organisations involved. The EU birds and habitats Directives, the national system of ‘sites of special scientific interest’and the UK Biodiversity Action Plan, have all influenced the development of a new approach in defining conservation objectives and targets for designated sites in the UK. The UK conservation agencies have agreed common standards for setting conservation objectives and targets as part of an overall monitoring and reporting framework. The rationale behind the approach and the common standards are described, together with some examples relating to freshwater habitats and species. Challenges for the future are identified and discussed.
Considerations for Recycling Sewage Effluent in the UK
Authors: Wishart S. J. , Mills S. W. , Elliott J. C.
Published: July 2007

Technical, environmental, legislative and institutional considerations in relation to effluent re‐use are described, with specific reference to experiences gained through the development of a scheme to augment Essex and Suffolk Water's Hanningfield reservoir with effluent from Chelmsford sewage‐treatment works. Effluent standards are driven by a number of EU directives associated with protection of fisheries, recreational water quality, eutrophication and nitrate control for designated sensitive areas, and surface‐water abstraction. The selection of the most appropriate strategy for re‐use needs to consider public perception issues, in addition to technical feasibility and environmental concerns.
Phosphorus Removal from Sidestreams by Crystallisation of Magnesium‐Ammonium‐Phosphate Using Seawater
Authors: Matsumiya Y. , Yamasita T. , Nawamura Y.
Published: July 2007

In recent years, a number of biological‐treatment processes have been developed for phosphorus removal, alone or in combination with nitrogen. In anaerobic/oxic and anaerobic/anoxic/oxic processes, it is necessary to lower the concentration of phosphorus in the sidestream from the sludge‐disposal processes. To do this, the magnesium‐ammonium‐phosphate system has been developed in which phosphorus is removed in a side‐stream process.

Alternative systems require chemicals such as magnesium chloride as the source of magnesium and sodium hydroxide for pH control, and are economically less viable than that described in this paper in which seawater is substituted for the chemicals.

Dissolved phosphorus removal of over 70% was achieved without pH control by feeding the sidestream which contained 50–111 mg/l dissolved phosphorus and had a pH greater than 7.77, together with a 9–10% flow of seawater into the reactor containing 4–13% of magnesium ammonium phosphate and which provided a retention of 29 mins.
External Quality Assessment of Microbial Counts from Water: To Score or Not to Score for Proficiency
Authors: Tillett H. E. , Lightfoot N. F. , Eaton S. , Place B. M.
Published: July 2007

Scoring schemes were first introduced in water‐chemistry inter‐laboratory proficiency tests. Such scoring does not behave in a comparable manner when applied to microbiology external quality assessment. Conventional scores can become a lottery. This poses a challenge to (a) find helpful statistical methods which will look beyond this natural variation and (b) attempt to identify any poor performance by the participants. The aim is to provide useful management tools.

In the Public Health Laboratory Service, water external quality assessment scheme participants have detected methodology problems. Formal analyses are carried out on cumulated results in two stages, first demonstrating whether there is any systematic difference between laboratories of microbiological as well as statistical significance and only then allocating participants to categories of acceptable, or poor, performance. The scheme has been operating for several years and performance improvements are evident.
Modelling the impact of Land‐Use Change to Water Resources in the Uplands of Scotland
Authors: Price D. J.
Published: July 2007

The predictions of a semi‐empirical evaporation model, and their implications to water resources for the uplands of Scotland, are presented for a range of land‐use and climatic scenarios. Three principal vegetation types (coniferous plantation forest, heather and upland grasses) are assessed. The model only requires daily rainfall, Penman potential evaporation, and snow line information as input data. A description of the modelling approach is given, and its performance is assessed by comparing its predictions to the water balances of nine partially afforested Scottish upland catchments.
New Insights into the Appraisal of Flood‐Alleviation Benefits: (1) Flood Damage and Flood Loss Information
Authors: Penning‐Rowsell E. C. , Green C.
Published: July 2007

New approaches to the appraisal of flood‐alleviation investment have been developed over the last twenty‐five years. This has led to (a) increased precision in benefit‐cost analysis, as better data have become available, and (b) a more rational approach to decision making as the UK Government has clarified and enhanced the decision criteria. This paper presents a detailed account of some of these developments, with an emphasis on the data on flood damages and losses avoided by flood‐alleviation schemes, and draws out lessons for those involved in this form of investment appraisal.
River Restoration: Public Attitudes and Expectations
Authors: Tunstall S. M. , Penning‐Rowsell E. C. , Tapsell S. M. , Eden S. E.
Published: July 2007

Public attitudes to restoration works on three rivers have been assessed using questionnaires and in‐depth interviews with local residents and restoration‐scheme managers, which were carried out after the implementation of the schemes. The results indicate that the restored rivers were well used and highly valued by the local public. At all three sites, the residents approved of the restoration work, and at two sites they considered that the schemes offered ‘value for money’. There were differences in the responses to the schemes at the different locations. The research suggests that greater benefits may be perceived in restoring urban rivers such as the Skerne.

Local residents attached importance to public consultation and expected to be consulted about river‐restoration works. On the basis of the three case studies and on the experiences of restoration practitioners, conclusions are drawn regarding consultation and involving local people in restoring and enhancing rivers.
The Use of Particle‐Size Counting in Minimising Cryptosporidium Risk at a Groundwater Supply Works
Authors: Hamilton P. D. , Standen G. , Evans A. D. , Doyle J. D. , Parsons S. A.
Published: July 2007

This paper examines the value of particle‐size counting and turbidimeters at a groundwater supply works in various modes, from the early commissioning of a full‐scale microfiltration plant through to process optimisation and monitoring. The relative strengths and weaknesses of particle‐size counters and turbidimeters are discussed in terms of their application.
Ammoniacal Nitrogen Removal in Biological Aerated Filters: The Effect of Media Size
Authors: Kent T. D. , Williams S. C. , Fitzpatrick C. S. B.
Published: July 2007

Recent legislation has led to stringent ammoniacal‐nitrogen consents and the need for first‐time sewage treatment in coastal areas where land is limited. This has led to the need to improve ‘small footprint’sewage‐treatment processes (such as biological aerated filters) which can be used for carbonaceous treatment, nitrification, or for combined treatment. The removal of ammoniacal nitrogen in filters containing different sizes of Lytag medium and operated for combined carbonaceous treatment and nitrification, was compared at different hydraulic and volumetric loading rates. The results suggest that filters containing the smallest media size (2–4 mm), gave optimum nitrification at ammoniacal‐nitrogen loading rates up to 0.6 kg/m3. d. At higher loading rates there was a rapid decrease in nitrification for this size of medium but, with 2.8–5.6 mm medium, nitrification continued at loading rates up to 1 kg amm. N/m3 d. The filters containing larger media sizes (4–8 mm and 5.6–11.2 mm) exhibited low levels of nitrification above a loading rate of 0.2–0.4 kg amm. N/m3. d.
Oestrogenicity and Wastewater Recycling: Experience from Essex and Suffolk Water
Authors: Walker D.
Published: July 2007

Research into possible endocrine disrupters and their effects, which is necessary to prove the safety of recycling schemes, is described. The research concentrated on the analysis of three steroid oestrogens and on trout bioassay (vitellogenin). The work was carried out in (a) experimental fish tanks using various mixtures of river water and treated wastewater, (b) pilot plants for wastewater and potable water treatment, and (c) monitoring the oestrogenic effects of discharging disinfected treated wastewater into Hanningfield reservoir during the 1995–98 drought. The overall conclusion is that the presence of minute traces of oestrogens in wastewater is not an insurmountable problem because they can be removed by dilution and self‐purification in rivers and reservoirs, by activated carbon and ultraviolet radiation in the recycling plant, and by ozone and activated carbon in water‐treatment plants.
The Impact of Disinfected Treated Wastewater in a Raw‐Water Reservoir
Authors: Walker D.
Published: July 2007

During the 1995–97 drought, serious difficulties were experienced by Essex and Suffolk Water in obtaining sufficient water to meet demand. As an emergency measure, a consent to discharge up to 30 Ml/d of ultraviolet disinfected treated wastewater into a raw‐water reservoir was obtained from the Environment Agency. Performance of the ultraviolet plant and results of monitoring are reported, reporting procedures are outlined, and the reaction of media and water consumers are described.
Additional Pollutants and Deposition Potential from Garbage Disposers
Authors: Galil N. , Shpiner R.
Published: July 2007

The objectives of this study were to (a) characterise the quantity and quality of crude sewage, as might be influenced by the use of domestic garbage disposers, and (b) examine the deposition potential of wastewater solids in gravitational sewerage systems.

Ground particles of organic origin require relatively low self‐cleansing velocities, and therefore conform with the usual design recommendations of gravitational sewers, with no expected deposition problems. However, ‘heavy’particles which are characterised by specific densities exceeding 2 and with sizes >1 mm, might cause deposition and associated problems. Where sewers are manufactured from smooth material, calculations indicate that higher scouring velocities than those recommended in the literature are required. Minimising the size of ground material by regulating the particle‐size distribution produced by approved garbage disposers should mitigate the problem which is caused by deposition.
Control and Stabilisation of Odorous Sludge from Fleetwood Sewage‐Treatment Works
Authors: Farrell P. D. , Nair A. , Palmer S. , Davies W. J.
Published: July 2007

Following completion of the construction of Fleetwood sewage‐treatment works in 1996, the sludge (from the plant) was causing health and safety problems for the workforce and there were complaints of odour from the local community. Problems arose due to overloading of the biological‐treatment units, resulting in little or no dissolved oxygen in parts of the process. There was a need to stabilise the sludge in the short term, culminating in the need for chemical conditioning, and an investigation into operational procedures to stabilise the sludge in the long term. The sludge was successfully stabilised using ferric chloride and sodium hydroxide. The long‐term stability of the sludge was further improved using operational changes (such as the inclusion of step feeding and by demonstrating the effect of load removal upstream from the existing biological process) via pilot‐plant studies.
A Comparison of International Standards for the Beneficial Use of Biomaterials: Can We See Where We Might Be Going?
Authors: Evans T.
Published: July 2007

Stakeholder confidence, environmental protection, and due diligence are fundamental to the sustainable recycling of biosolids and other organic residuals. Open, independent, expert validation of recycling should be an important support to, and underpin, the entire process.

This paper (a) draws from information gathered during European Standards’work, and from other sources, to explore the consistencies and differences which exist between countries, (b) explores why some of these differences have arisen, (c) discusses the recommendations for future improvements, and (d) recommends that the recyclers of residuals should be more proactive in order to maximise their opportunity to influence and direct their destinies.
Sources and Implications of Uncertainty for Coastal Managers
Authors: Hall J. W. , Davis J. P.
Published: July 2007

This study included semi‐structured interviews with eight practitioners who have key roles in UK coastal management. Data from the interviews were analysed using ‘grounded theory’, which established that sources of uncertainty in decision making are diverse but can be categorised as being modelling issues, values issues, communication and ‘externalities’. At present, intuitive and implicit methods of taking uncertainty into account in decision making are much more prevalent than explicit methods. By identifying sources and implications of uncertainty, coastal managers will be in a stronger position to promote resilient systems that can cope with changing natural and social conditions.
Application of a Biological Iron Removal Process at Grove Water‐Treatment Works
Authors: Morris T. , Siviter C. L.
Published: July 2007

This paper describes the process of biological iron removal with specific reference to the new water‐treatment plant at Grove (near Retford), operated by Anglian Water Services. The reasons for selection of a biological‐treatment process are discussed together with process design, commissioning experiences, and details of plant performance.

The raw‐water data suggested that a biological removal process would be feasible and would offer capital cost savings over a conventional aeration and filtration process. Further investigations were carried out in a pilot plant. A summary of the data which were collected during the performance trials is presented, which demonstrates the successful application of the process.
Water Resources in the Twenty‐First Century: A Global Challenge
Authors: Macdonald A.
Published: July 2007

This paper reviews the global demand for water resources in the first part of the twenty‐first century and draws attention to initiatives to improve access to safe water for the world's population. It highlights the benefits of the adoption of an integrated water‐resources management strategy, drawing on a recent case study in Africa, and suggests guidelines for the framework to be adopted in such a strategy. The role of private‐sector participation in water‐resource development in developing and emerging economies is reviewed, and key aspects (related to its success) are highlighted.
Integrated Lake and Catchment Phosphorus Model– A Eutrophication Management Tool. I: Model Theory
Authors: Daldorph P. W. G. , Lees M. J. , Wheater H. S. , Chapra S. C.
Published: July 2007

The paper describes an integrated lake and catchment model which was developed and tested against data from the Rutland Water catchment (River Nene and Welland) in Eastern England. The model uses export coefficients to predict annual diffuse losses of phosphorus from catchment land use, which are temporally disaggregated using empirical relationships between phosphorus load and discharge in headwater streams. Dynamic inputs of phosphorus are incorporated into a hydrologically based, multi‐reach distributed catchment model which also simulates sewage discharges, abstractions and reservoirs/ lakes. The model allows a comparison of simulated output with observed discharge and water‐quality data from various points within the river system.
Factors Affecting the Performance of a Packaged Sewage‐Treatment Plant
Authors: Hodkinson B. J. , Williams J. B. , Butler J. E. , May E.
Published: July 2007

This paper describes the performance of a small packaged plant serving about 70 people and incorporating submerged aerated filters. The diurnal variation was typical of a small sewage‐treatment works, and the final effluent was well stabilised with average BOD and amm.‐N concentrations of 12 mg/l and 3.8 mg/l respectively.
Development of a UK Database for Predicting Flood Levels for Overbank Flows
Authors: Babaeyan‐Koopaei K. , Ervine D. A. , Sellin R. H. J.
Published: July 2007

Every year, major disasters and the associated damage and loss in the UK cost millions of pounds. One of the many ways that river engineers have responded to this is to collect and upgrade the amount, and quality, of the information about floods (inland and coastal). This paper reports on a research project which aims to (a) consolidate all existing data on overbank flows over a range of scales, and (b) prepare them for publication on the ‘worldwide web’. The data are classified into three major groups, i.e. small‐scale models, large‐scale models, and field data. The data contain information on stage discharge, cross‐section geometry, channel‐plan form, sinuosity, and channel boundary roughness. Using the collected data, a simplified dimensionless stage‐discharge relationship is developed. The results reveal that, using this equation, the stage within 10%, and discharge within 20%, of the measured values can be predicted.
The Use of Sediment Modelling Techniques to Address the Differing Needs of Management on the River Eden, Cumbria, UK
Authors: Walker J.
Published: July 2007

Sediment modelling techniques are applied to the River Eden at Great Musgrave (in Cumbria) utilising (for the first time) the software ISIS‐Sediment for UK gravel‐bed rivers. This work was undertaken in an attempt to determine any potential adverse geomorphological impacts which may result from the development of a weir for flood‐warning purposes. The modelling exercise found that the development of the weir was unlikely to significantly affect sediment transport, and therefore would not impact upon the morphological characteristics of the river bed in the vicinity of the weir. Site investigation, subsequent to the construction of the weir, confirmed that the findings of the modelling exercise were fundamentally correct.
Practical Implications of the Use of Groundwater‐Protection Tools in Water‐Supply Risk Assessment
Authors: Morris B. L.
Published: July 2007

The tools of vulnerability mapping and groundwater‐protection zoning were developed during the early 1990s to enable the National Rivers Authority and its successor (the Environment Agency) to realise a national ground‐water‐protection policy for England and Wales. The resultant maps and protection zones cover more than 2250 public water supplies, tapping over 160 aquifers, and took almost five years to prepare. An opportunity for the UK water industry to assess their usefulness arose in 1999 when new Government regulations required water companies to conduct risk assessments for the troublesome parasite Cryptosporidium, and this paper reviews some results of that exercise. In the light of widespread doubts about the effectiveness of sporadic monitoring alone, in protecting the health of users of private ground‐water supplies, a simple and pragmatic pollution hazard assessment procedure is suggested, employing combined use of sanitary surveys with an aquifer vulnerability flowchart.
Comparison of Vertical‐Flow Constructed Wetlands for the Treatment of Wastewater Containing Lead and Copper
Authors: Scholz M. , Xu J.
Published: July 2007

This paper describes an investigation into the treatment efficiency and capital cost of vertical‐flow constructed‐wetland filters containing different plant communities and granular media with different adsorption capacities. The media included gravel, sand, granular‐activated carbon, charcoal and filtralite (light expanded clay). Lead and copper sulphate were added to a polluted urban beck inflow water to simulate pretreated minewater or highway runoff. The interactions between growth media, microbial and plant composition and the reduction of lead, copper and BOD were investigated. For filters containing traditional media, a breakthrough of copper was recorded during the first nine weeks. After maturation of the biofilm, the wetlands performed well.
The Role of Coal Recovery in the Reclamation of the Merthyr Vale Colliery Site, South Wales, UK
Authors: Brooks C. , Davies A. J. , Williams K. P.
Published: July 2007

This paper describes the reclamation of the Merthyr Vale colliery site and shows that the incorporation of coal recovery produced economic, as well as environmental, benefits. The optimum plant throughput for a 2.1 m dia. barrel washer was 120 t/h at an operating density of 1200 kg/m3. Coal and discard qualities were acceptable, and the final landform was suitable for development with few restrictions.
Modelling the Performance of Combined‐Sewer Overflow Chambers
Authors: Harwood R. , Saul A. J.
Published: July 2007

This paper reviews some of the physical model studies which have been carried out in the UK to determine the performance of combined‐sewer overflow chambers. The topic of computational fluid dynamics is introduced and identified as a viable alternative to physical modelling. The limitations of both modelling approaches are discussed. It is concluded that the future of chamber modelling will be a combination of computational fluid dynamics and physical techniques.
Economics of Recovering Value from Recycling Treated Biosolids to Land
Authors: Soulsby P. G. , Hickman G. A. W. , McMahon P. L.
Published: July 2007

This paper demonstrates the economic value of recycling treated biosolids to land in terms of (a) the effect on agricultural yield and (b) the avoidance of environmental and social costs of using conventional mineral fertilisers. Replicated field trials show that yield increases can be achieved when biosolids are used in conjunction with mineral fertilisers, compared with using conventional fertilisers. Relevant environmental and social costs of the production and use of both nitrogen and phosphate fertilisers and recycled biosolids are estimated. By recycling biosolids to agricultural land, the external costs associated with conventional mineral fertilisers can be fully recovered. The total replacement value of biosolids is the sum of the values of the increased yields and the replaced external costs. For digested cake this is equal to £2.64/tonne and for granules £10.85/tonne; in both cases the replacement value exceeds the external costs of biosolids. These costs and benefits should be taken into account in the development of environmental policy related to wastewater treatment.
Water‐Supply Management in Sudan: 2000 Onwards (Abridged)
Authors: Omer A. M.
Published: July 2007

Thirty‐four million people live in Sudan, and environmental pollution is a major concern throughout the country; therefore, an integrated approach should be adopted by industry, communities, local authorities and central government, to deal with pollution issues. Most polluters pay little or no attention to the control and proper management of polluting effluents: furthermore, the imposed fines are generally too low and do not deter potential offenders.

The paper discusses the overall problem and identifies possible solutions.
Cost‐Effective Integrated Drainage and Wastewater Management Systems
Authors: Iwugo K. O. , Andoh R. Y. G. , Feest A. F.
Published: July 2007

This paper presents an overview of the components of wastewater management systems with particular reference to the emerging ‘pollution preventative’source‐control system which accords more with ‘nature's way’and sustainable‐development principles. The types and characteristics of pollutants, and also the ease of the removal of pollutants from wastewaters and the aquatic environment, are discussed. The source‐control system is compared with the traditional conventional system on the basis of technical, economic, socio‐cultural and environmental appropriateness in order to aid integrated drainage and wastewater treatment system selection and decision making ‐ particularly in developing countries.
Permeation of Organic Chemicals Through Plastic Water‐Supply Pipes
Authors: Goodfellow F. , Ouki S. K. , Murray V.
Published: July 2007

This paper discusses the problem of permeation of organic chemicals through plastic water‐supply pipes, resulting in drinking‐water contamination. Case studies are reported where contamination has resulted in taste and odour problems for customers, and might pose a risk to health. It is therefore recommended that (a) guidance is provided for water companies and building contractors, specifying when it is inappropriate to use unprotected plastic pipes for the provision of drinking water, and (b) measures are taken to ensure adherence to this guidance.
Colecott Hybrid Reed‐Bed Treatment System: Design, Construction and Operation
Authors: O'Hogain S. , Gray N. F.
Published: July 2007

The use of hybrid reed‐bed treatment systems to treat domestic sewage has become widespread in mainland Europe and the UK. However, in Ireland, the application of combined vertical and horizontal beds is still at an experimental stage. The existing septic‐tank system at Colecott (County Dublin) was upgraded by the construction of vertical and horizontal reed‐beds in series. This paper discusses the rationale behind its selection, design, construction and operation.
Water‐Quality Monitoring in Anguilla
Authors: Parr J. , Rogers J.
Published: July 2007

Anguilla is a UK overseas (non‐independent) territory in the Caribbean. It is a small middle‐income island with a population of 13 000, and recent statistics indicate that it is more dependent on tourism than any other country or territory in the world. Rapid population growth and development have placed more emphasis on the need for human health and environmental protection. For the first time, a systematic water‐quality monitoring programme has been developed, based on the realities of the local situation, e.g. low resource base, limited capabilities, dependence on household rainwater catchment, storage cisterns, and a poor water‐supply network. Development of the programme incorporated the key themes of pragmatic, realistic, incremental, responsive, and consultative approaches.
Phosphorus Release and Fertiliser Value of Enhanced‐Treated and Nutrient‐Removal Biosolids
Authors: Smith S. R. , Triner N. G. , Knight J. J.
Published: July 2007

This paper describes a soil‐incubation study which was carried out to examine the effects of (a) phosphorus removal during the treatment of domestic sewage and (b) treating sewage sludge to an enhanced status, on the phosphorus fertiliser value of biosolids which are used in agriculture. Phosphorus‐enriched and conventional dewatered digested biosolids, thermally‐dried pellets and granules, and digested and thermally‐hydrolysed liquid sludges were incorporated into two soil types with contrasting physico‐chemical properties. Plant‐available phosphorus in soil was assessed after incubation by a standard chemical‐extraction procedure. Sludge from biological‐P removal had the highest phosphorus extract‐ability in soil whereas iron dosing slightly reduced or had no effect on phosphorus release from conventionally‐treated biosolids, depending upon the type of soil. High‐temperature drying significantly reduced the extractable‐P content in sludge by 20–60%, compared with dewatered digested cake, and release from thermally‐dried biosolids declined further with iron enrichment. Extractable‐P recovery was greater from all types of biosolids when mixed with calcareous soil, compared with a loamy sand. A preliminary investigation of phosphorus mineralogy in biosolids, using advanced analytical techniques, is also described.
The Use and Application of Particle‐Count Data in Water Treatment
Authors: Bridgeman J. , Simms J. S. , Parsons S. A.
Published: July 2007

Particle counters are widely used in the water industry and generate a significant amount of data. To be useful to operators, such data need rapid interpretation. This paper describes how poor individual filter performance can be detected from particle‐size analysis of the combined filtrate from a block of six rapid‐gravity filters. Relationships between particle counts in the 2–5 μm size range and total count are explored, and the concept of an onsite real‐time alarm system, monitoring differential particle‐count data from combined filtrate, is developed.

Consideration is given to the frequency of data collection. Whilst all major events were detected by collecting regimes with collection frequencies varying from 5 to 45 mins, it was found that the governing factor in determining collection frequency is the response time required by the operator to an incident.
Evaluation of the FEH Rainfall‐Runoff Method for Catchments in the UK
Authors: Ashfaq A. , Webster P.
Published: July 2007

The Flood Estimation Handbook, which was published in 1999, has substantially replaced the Flood Studies Report for design flood estimation in the UK. Although there are substantial differences between the handbook and the report, the philosophy of the rainfall‐runoff method has been retained in the handbook. However, there are differences in the equations that have been used to estimate parameters of the rainfall‐runoff method.

This paper provides a comprehensive evaluation of the performance of the Flood Estimation Handbook rainfall‐runoff method for flood‐frequency estimation, using data from eighty‐eight catchments in the UK. The performance is evaluated by reference to the flood quantiles obtained from single‐site frequency analysis, and comparison is made with the performance of the Flood Studies Report methodology. In general terms, the handbook over‐estimates flood quantiles, with respect to (a) those estimated from observed records and (b) the report's quantiles. The paper explores the causes of these over‐estimations and seeks linkages with particular catchment characteristics.
Domestic Water Demand Forecasting: A Static Microsimulation Approach
Authors: Williamson P. , Mitchell G. , McDonald A. T.
Published: July 2007

Planning the provision of a future water supply depends upon forecasts of likely demand. Existing forecasting techniques suffer from a lack of spatially relevant information on likely trends in the micro‐components of demand. At a sub‐regional level, current approaches also understate between‐area variability. A static micro‐simulation model is described, which makes more efficient use of existing data in producing forecasts of domestic water consumption. Spatially detailed synthetic microdata are reweighted towards level population estimates which are derived from official Government population projections. A 30% increase in domestic consumption between 1991 and 2025 is forecast for the Yorkshire Water region, three‐quarters of which is attributable to changes in consumer behaviour.
Sludge to Land: Microbiological Double Standards
Authors: Mara D. D. , Horan N. J.
Published: July 2007

The microbiological requirements for enhanced treated sludge in the Safe Sludge Matrix are reviewed and compared with those for foods, which are much less stringent. Quantitative microbial risk analysis shows that the risks to human health from disease transmission through sewage sludge to grazing animals or food crops are very low, indicating that the strict requirements of the Safe Sludge Matrix are not really justifiable.
The Hydro‐Ecology of Limestone Springs in the Wye Valley, Derbyshire
Authors: Smith H.
Published: July 2007

Springs are unique freshwater habitats and represent ideal sites in which to examine the relationship between environmental variables and macro‐invertebrate communities. The results of three case studies infer that species assemblages are determined by the physical habitat conditions within a spring and the ecological requirements of the component species. The composition of the macro‐invertebrate community changes significantly along the longitudinal gradient of a spring‐brook, as predicted by ecological theory. The results of the case studies are examined in relation to the conservation and protection of these little‐studied habitats, and suggestions are made as to how to achieve this in the Wye Valley.
Low‐Cost Solutions for Trihalomethane Compliance
Authors: Banks J. , Wilson D.
Published: July 2007

Compliance with the new trihalomethane standard is a major item in Yorkshire Water's water‐quality capital programme using conventional granular activated‐carbon filters as the final stage of treatment. Detailed investigations were carried out at three water‐treatment works to find an alternative solution which would ensure compliance at a lower cost and with minimum disruption to the existing treatment process. Low‐cost solutions were tailor made at each site, where possible modifying the existing process to improve the removal of organic material.

The key to the success of this work was the use of ultraviolet light absorbance at 254 nm as a surrogate for precursors for the investigatory phase, making modifications easy and quick to evaluate, for modelling trihalomethane formation and, ultimately, by the plant engineer.
Challenges to the Implementation of the Water Framework Directive in Scotland: A Personal View
Authors: Walker S.
Published: July 2007

The Water Framework Directive was implemented in December 2000 and has to be transposed into Scottish legislation by 2003. The Directive provides a major opportunity to enhance the water environment of Scotland and to improve its management through the implementation of river‐basin management planning with stakeholder and public engagement and the delivery of a programme of environmental‐improvement measures to deliver good ecological status. Whilst the Directive provides unparalleled opportunities, there are significant challenges to its successful implementation in Scotland, where a step‐change in managing the water environment will be required. This paper explores some of the challenges which include technical aspects, scale and timing issues, and capacity limitations.
Water‐Treatment Works’Sludge Management
Authors: Owen P. G.
Published: July 2007

In the UK, the disposal of wastes from the production of potable water has been an increasing problem for water companies since the introduction of the Waste Management Licensing Regulations in 1994. This paper considers alternative management strategies. The importance of investigating each works individually is stressed because of variations in sludge properties and disposal costs. Of the disposal options, the growing of turf is environmentally sustainable and economically attractive, whereas direct spreading on agricultural land and use in soil production can be successful. Other uses, e.g. in ceramics, are at various stages of development; co‐disposal with sewage is an option, but hidden costs need to be assessed.
Water‐Availability Assessment and Corresponding Public‐Health Implications for a Rural Area in Nigeria
Authors: Uzomah V. C. , Scholz M.
Published: July 2007

This paper presents a case study which describes water‐availability problems and corresponding public‐health implications for a rural area in Nigeria. A water‐availability assessment was carried out in eight villages which are controlled by the Jalingo Local Government of Taraba State. Questionnaires were used to obtain data from sixty households (approximately 650 participants) concerning issues of water‐supply sources, water quantity, water quality and community participation in water‐resources projects. It was found that (i) community well water is the major source of water, (ii) 35% of the inhabitants depend on well water during the wet season, and (iii) 69% depend on it during the dry season. About 80% of the households have access to less than 30 litres of water per person per day and, because of low water availability, there is a prevalence of water‐related diseases.
DECAY OF ESCHERICHIA COLI IN SOIL FOLLOWING THE APPLICATION OF BIOSOLIDS TO AGRICULTURAL LAND
Authors: Lang N. L. , Smith S. R. , Bellett‐Travers D. M. , Pike E. B. , Rowlands C. L.
Published: July 2007

The decay of Escherichia coli in a sandy loam soil, amended with enhanced and conventionally treated biosolids, was investigated in a field experiment following spring and autumn applications of sewage sludge. Control soils, without the application of biosolids, were also examined to determine the background indigenous populations of E. coli which are present in the environment. The survival of indigenous E coli and populations of E coli applied to soil in biosolids, is assessed in relation to environmental factors influencing pathogen‐decay processes in soil.