bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statutory Water Quality Objectives and River Water Quality
Authors: SEAGER J. 
Published: July 2007

AbstractThis paper summarizes some of the key issues which have been considered in developing proposals for a scheme of classifying river quality for the purpose of setting water quality objectives on a statutory basis. Particular attention is given to (a) the relationship between use‐related and general water quality targets, (b) the role of biological assessment, and (c) the requirements of EC directives. Following widespread consultation on the proposals, it was concluded that a clear distinction should be made between sets of ‘use classes’which would serve to set statutory water quality objectives (SWQOs) and a general quality assessment scheme which would be applied independently to assess trends and general progress over a period of time. Once the classification scheme has been established by the Secretaries of State through regulations, SWQOs will be introduced to river stretches in a number of ‘pilot’catchments across England and Wales, following local consultation. The setting of SWQOs will provide the focus for local decision‐making on what the appropriate level of water quality should be – taking into account the desired uses of rivers, what will be required to achieve them, and the associated costs.
Automatic Monitoring of Activated Sludge Settling Characteristics and Plant Control Applications
Authors: C. REID J. M. , NASON R. B. 
Published: July 2007

AbstractA fully automatic instrument has been developed to allow the on‐line measurement of activated sludge settling characteristics. The monitor uses the derived data to calculate final sedimentation tank solids loadings and the required rates of returned activated sludge pumping. The instrument has been developed by Thames Water Utilities Limited and is now manufactured under licence by Phox Systems Ltd. It samples mixed liquor and returned sludge alternately and measures solids concentration, the initial settling rate (or rate of hindered settlement) and the stirred specific volume index. The stirred specific volume index at a standard solids concentration of 3.5 g/l is derived from the data. Actual and maximum final sedimentation tank loadings (kg/m2h) are calculated, and the required returned sludge pumping rate is predicted and may be controlled by the monitor. Tests have been carried out on a number of sewage‐treatment works during several years of development, and some of the results are presented and discussed.
Charging for Discharges and Integrated Pollution Control in Scotland
Authors: LEATHERLAND T. M. 
Published: July 2007

ABSTRACTThe year 1992 saw the successful implementation in Scotland of charging schemes which recover the cost of regulating authorized discharges into water and into the atmosphere. The new schemes recover from dischargers those costs of the regulatory authorities arising directly from the regulation of consented and authorized discharges. These costs were previously part of the country's overall public expenditure. The schemes operated by the river purification authorities are particularly fair because costs and charges are balanced for every individual discharger, rather than across the regulatory function as a whole. Charges therefore vary substantially both within and between river purification board areas, but a comparison of actual charges raised by the Forth River Purification Board with estimated National Rivers Authority charges indicates that the Scottish charges are generally lower. The absence of an incentive charging element contrasts with a recent recommendation of the Royal Commission on Environmental Pollution.
Controlling the Artesian Boreholes of the South Lincolnshire Limestone
Authors: BARTON B. M. J. , PERKINS M. A. 
Published: July 2007

ABSTRACTThis paper describes (i) a long‐established, serious and growing problem in a part of the Anglian Region of the National Rivers Authority due to uncontrolled leakage of groundwater from old artesian boreholes (‘wild bores’) in the South Lincolnshire Limestone aquifer, and (ii) a remedial project recently undertaken by the Authority. The paper discusses (a) the nature of the problem and its implications for water resources, (b) the means employed to carry out the work, (c) environmental considerations, and (d) the results of the project.
Accounting for Losses: The Bursts and Background Concept
Authors: LAMBERT A. 
Published: July 2007

ABSTRACTLosses of treated water occur through leakage and overflows from the pressurized pipes and fittings in water undertakers’distribution systems and customers’private supply pipes. The UK National Leakage Control Initiative was formed in 1991 to update previous published work on leakage control policy and practice in the UK.Although some published technical relationships exist, there has been no overall methodology which attempts to provide a component‐based estimate of annual losses in different parts of the distribution system for any particular combination of local circumstances, i.e. pressure, burst frequency, burst flow rate, number of properties, length of mains, method of leakage control, standards of service, and waste notice service/enforcement policy.The ‘bursts and background estimate’spreadsheet‐based methodology is designed to provide such estimates. It links ‘night‐flow’and ‘annual losses’concepts, and can be used for a variety of purposes. These include (a) assessment of the likely incidence of losses for different leakage control and waste notice policies, (b) identification (from night flows) of districts in which there are unreported bursts, and (c) assessment of economic target levels for leakage control. The substantial element of annual losses from service pipes, and the considerable influence of pressure on annual losses, are also discussed.
Statutory Water Quality Objectives on the River Cam
Authors: TESTER D. J. 
Published: July 2007

ABSTRACTThe Government has announced its wishes to gradually introduce statutory water quality objectives in pilot catchments, commencing in late 1993. The River Cam is one of the catchments under consideration.The paper describes the main physical features of the River Cam and its uses, which include salmonid and cyprinid fisheries, agricultural and industrial abstraction, and recreational pursuits.Significant sewage and industrial discharges in the catchment, and their impact on water quality, are discussed, and current river quality is compared with established river quality objectives, EC requirements and proposed statutory water quality objectives. Procedures for setting the latter objectives are considered, together with monitoring and compliance assessment. Future effluent discharge standards are proposed, and options to achieve long‐term water quality targets are suggested as part of a catchment management action plan.
Wastewater Rapid‐Gravity Filtration in Severn Trent Water
Authors: LANDER J. 
Published: July 2007

ABSTRACTIn Severn Trent Water, rapid‐gravity filtration is used as a tertiary treatment process on a number of large sewage‐treatment works, and is likely to find further use in meeting more stringent discharge quality limits in the future. Design maximum hydraulic loadings and average suspended‐solids loadings are identified, and average hydraulic and solids loadings for 1989–91 are presented. Established filters are hydraulically underloaded, but on average suspended‐solids loadings they are mostly overloaded due to relatively poor quality influents. High mean solids and BOD removals are achieved. Reduced medium relative density has been found to vary with the degree of fouling and causes over‐expansion of the bed and medium loss. A correlation has been demonstrated between relative density and percentage dry matter, which could be used to assess the degree of medium fouling.
The Treatment of Weathered Crude Oil in Kuwait
Authors: SHABAN H. I. 
Published: July 2007

ABSTRACTDuring the Gulf War about 740 oil wells were blown up by the Iraqi forces, and the unburnt oil flooded from these wells to form oil lakes. This resulted in one of the largest oil slicks in the world, causing serious damage to the marine life in the Gulf region. The oil which is exposed to atmospheric weather over a period is called ‘weathered crude oil feed stock’, and it is important to treat this oil not only from the economical point of view but also to consider the environmental pollution which is created. The Government of Kuwait, represented by Kuwait Oil Company (KOC) has made its best attempts to treat this oil, and most of the oil lakes have now been cleared. The objective of this study is to report and evaluate different treatment methods and measures to control and manage these oil lakes.
Managing Agricultural Pollution Using a Linked Geographical Information System and Non‐Point Source Pollution Model
Authors: MORSE G. , EATHERALL A. , JENKINS A. 
Published: July 2007

ABSTRACTThis study documents the development of a link between a geographical information system (GIS) and a non‐point source pollution model. The GIS ARC/INFO was linked to the agricultural non‐point source pollution model and ORACLE data sources. Application of the system is demonstrated using the Bedford‐Ouse catchment as a suitable case study. Water quality impacts are predicted from source data describing topography, soils, land use and river network. The model results were in agreement with observed nitrate concentrations at the catchment outlet, and more appropriate data sources are considered to be the main priority for improving model predictive ability. Management scenarios were established to assess the impact of changing agricultural management practices on predicted water quality. The approach has significant potential for the management of agricultural pollution in the UK.
Seasonal Variations in the Quality of Spring Waters Used as Private Supplies
Authors: PETRIE A. S. , HORAN N. J. , CLAPHAM D. B. , CRAM A. G. 
Published: July 2007

ABSTRACTThe quality of water issuing from four springs which act as private water supplies was monitored regularly over a twelve‐month period. Bacteriological analyses for faecal coliforms and chemical analyses for iron, manganese, aluminium and lead were carried out and related to meteorological conditions. Bacteriological quality, which was influenced by the amount and duration of rainfall, deteriorated rapidly after heavy rain and improved markedly during dry periods. Chemical quality was a function of both the rainfall and atmospheric pollution emanating from the nearby urban conurbation. The results are discussed with relation to the statutory requirements for local authorities to monitor small private water supplies.
The Effect of Chlorinated Water on the Pesticides Prometryn and Terbutryn
Authors: FAIRHEAD A. P. 
Published: July 2007

ABSTRACTThe pesticides prometryn and terbutryn are shown to be broken down by the chlorination process. The reaction is rapid and pH‐dependent. By analogy, a number of similar compounds are expected to be affected in the same way. The importance of considering the breakdown products of pesticides is discussed.
An Assessment of the Impact of Inland Surface Water Input to the Bacteriological Quality of Coastal Waters
Authors: WYER M. D. , JACKSON G. , KAY D. , YEO J. , DAWSON H. 
Published: July 2007

ABSTRACTThe introduction of ultraviolet disinfection in Jersey has achieved significant improvements in water quality. However, bathing waters in St Aubin's Bay and shellfish flesh have failed to comply with microbial standards. Streams and seepages from coastal structures were investigated as potential indicator organism sources (total and faecal coliforms, faecal streptococci). Seepages were an unimportant bacterial source as concentrations were low. Geometric mean concentrations in streams were up to four orders of magnitude higher than in final sewage‐treatment works effluent, and concentrations increased significantly at high stream discharge. Rainfall‐induced pulses of poor water quality occurred two to three times per week during the 1993 summer season. Natural discharges from island catchments thus contribute significantly to the bacterial load received at the coast, especially during high flow events. These observations have implications for other UK and European schemes using tertiary disinfection technology to attain water quality targets in coastal waters.
Low‐Cost Remote‐Sensing Techniques Applied to Drainage Area Studies
Authors: SCOTT A. 
Published: July 2007

ABSTRACTThe paper describes a project in which colour and infra‐red video images were used as the basis for assessing the percentage impermeability of subcatchments for a WALLRUS model. The imagery was obtained from helicopter‐mounted video cameras. Computer processes were developed to convert raw data, which were in analogue format, into a format which could be manipulated and displayed by the computer. The computer was able to assess the total permeable and impermeable areas in each subcatchment. These data were used in the WALLRUS model and compared with the results obtained using manually derived data and results from the flow verification survey.
Aqueduct Management Planning: Thirlmere, Haweswater and Vyrnwy Aqueducts
Authors: CRITCHLEY R. F. , AIKMAN D. I. 
Published: July 2007

ABSTRACTBetween 1988 and 1992, an asset study of North West Water Limited's three largest aqueducts was carried out to assess their condition and rehabilitation needs. About 360 km of the aqueduct system, including approximately 1700 structures, 160 km of tunnel and conduit, 700 km of pipeline and 4000 valves, were covered by the study. A wide range of survey techniques was used, some being specially developed as part of the study, and a unified system of condition assessment and prioritization of rehabilitation needs was devised.The paper (a) describes the overall approach and survey techniques, (b) discusses the methods of assessment used, (c) summarizes the conditions of the assets whose ages vary from 20–100 years, and (d) reviews some of the rehabilitation works proposed and executed.
Foam Formation, Anaerobiosis and Microthrix Parvicella
Authors: CHACIN E. , KOCIANOVA E. , FORSTER C. F. 
Published: July 2007

ABSTRACTMicroscopic examinations of the sludges associated with two incidents of foam formation in anaerobic digesters are described. In both cases, the dominant filamentous species was Microthrix parvicella. Preliminary growth studies with this species indicated that it could grow in both aerobic and anaerobic environments, but that in an anaerobic regime it did not produce polyphosphate granules. This suggests that M. parvicella may be involved in the luxury uptake of phosphate and, under strict anaerobic conditions, could compete with acetoclastic methanogens for acetate.
Sea‐Water Infiltration: The Dramatic Corrosion of Ductile‐Iron Rising Mains
Authors: LONG M. J. 
Published: July 2007

ABSTRACTRepeated failures of a ductile‐iron sewage rising main, after only three years’ use, led to an investigation into the cause of the problem. Of particular concern was the fact that a pipe failed at an operating pressure of less than a quarter of its nominal 40‐bar rating after such a short period. Serious internal corrosion, concentrated along the soffit of the rising main, resulted in tensile failure under pressure.An analysis of the sewage revealed high concentrations of chloride and sulphate, resulting from major infiltration of sea water into the sewerage system.The combination of the high concentrations of inorganic sulphates, and the presence of sulphate‐reducing bacteria normally found in domestic sewage, is believed to have resulted in the production of a large concentration of hydrogen sulphide which was then oxidized to sulphuric acid by air entrained at the pumping station.
The Development of a Waste Management Policy in Northern Ireland
Authors: WILCOCK D. N. 
Published: July 2007

ABSTRACTWith one or two isolated exceptions, waste management in Northern Ireland is not practised as a sequential process of waste avoidance, recycling and disposal by the best practical option. In order to update waste management practice in the province, the Government proposes to implement most of the waste management provisions contained in the Environmental Policy Act, 1990. Waste regulation will be made the responsibility of central government, while waste disposal and recycling will be the responsibility of central government, while waste disposal and recycling will be the responsibility of local authorities. The policy will have to be implemented within a set of distinctive social, political, geographical and economic factors which raise a number of questions as to the best way forward.
Setting Effluent Consent Standards
Authors: ROSS S. L. 
Published: July 2007

ABSTRACTThe paper outlines how consent standards are normally calculated in Scotland for both river systems and tidal waters. A background is given to the reason why a more statistical approach has been adopted in England and Wales where the use of combining distribution methods is more widespread. Comparison of the two approaches is made, particularly with regard to their potential impact on resources required for treatment plants, and also the problems of taking enforcement action. The setting of standards under the EC urban waste water treatment Directive is considered where, in addition to the implications of primary, secondary and more stringent treatment, consideration is given to storm‐sewage overflows and industrial discharges.
The East Kent Chalk Aquifer during the 1988‐92 Drought
Authors: CROSS G. A. , RUSHTON K. R. , TOMLINSON L. M. 
Published: July 2007

ABSTRACTGroundwater resources of Chalk aquifers may become depleted during drought periods; major causes of this depletion include reductions in the aquifer transmissivity and the interaction between aquifers and rivers. In the East Kent aquifer there are certain catchments where difficulties are encountered in maintaining yields but, in other catchments, drought periods have little effect on the available resources. A mathematical model is developed to help understand the flow processes within the aquifer system, and the model is used to predict the consequences of possible abstraction scenarios.
Boat Wash at Channel Banks
Authors: GADD G. E. 
Published: July 2007

ABSTRACTThe general characteristics of boat wash, as affected by boat speed and water depth, are discussed. The classical deep‐water wave pattern, with the most prominent waves at the forward edges of a V‐shaped region of semi‐angle 19 1/2°, becomes modified at high speeds. The effective angle of the V is then reduced and the waves become very long‐crested.In moderately shallow water, the level of the water surface close to the boat (on either side of it) can be depressed by an amount which is greater than the amplitude of the downstream waves. In still shallower water, for boat speeds which would cause appreciable waves in deep water, the boat squats markedly and makes very large waves.Possible implications of these facts for bank erosion are discussed.
Computer Models for Quantifying the Hydro‐Ecology of British Rivers
Authors: JOHNSON I. W , LAW F. M 
Published: July 2007

ABSTRACTIn recent years, the use of models and scoring surveys for assessing the environmental impacts associated with river‐engineering works has increased. This paper discusses the circumstances in which modelling may be needed, and gives details of some of the models currently in use and under development. River corridor surveys, HABSCORE, RIVPACS (River Invertebrate Prediction and Classification System), SERCON (System for Evaluating Rivers for Conservation) and QUASAR (Quality Simulation Along Rivers) are described, and more detailed information is given on the IFIM (Instream Flow Incremental Methodology using PHABSIM), the physical habitat simulation approach being tested for the National Rivers Authority and the Ministry of Agriculture, Fisheries and Food.
Basingstoke Canal Hydrological Study: A Water Balance
Authors: PINKETT A. J 
Published: July 2007

ABSTRACTThe paper describes a hydrological study to investigate causes and potential solutions to a significant shortfall of water in the Basingstoke Canal. Canal inflows and losses were investigated under drought and average summer conditions, and spring yields, streams, piped drainage and pumped inflows were assessed. Losses included evaporation, seepage, weirs and lock usage. A computer model of the complete water balance in the canal was created for the 29 pounds† for different levels of canal usage under three meteorological scenarios. This showed the balance of water stored, and in shortfall or excess, for each month over a year of operation for each pound.Field investigations, which were carried out to verify the model and to refine preliminary estimates, included flow measurement, site investigation, groundwater level monitoring and water‐quality testing. Recommendations were made on potential solutions to the problem of water shortage to achieve different levels of canal usage.
Pumping Machinery in the Mid‐1990s
Authors: GIBSON D. C. 
Published: July 2007

AbstractThe paper by Towler(1) described the design, construction and testing of a pumping installation which incorporated a triple‐expansion Cornish steam engine with an integral three‐ram positive‐displacement pump. This paper contrasts and discusses the developments, with pumping machinery, which have taken place during the last 100 years.
Design of the Thames Water Ring Main
Authors: Farrow J. P , Claye P. M 
Published: July 2007

ABSTRACTThe Thames Water ring main is a 2.5 m dia. tunnel approximately 50 m below ground and 80 km long, which conveys potable water from major treatment works, located west of London, into central London. The scheme was constructed during the late 1980s and early 1990s.In 1985, to meet increasing water demand, a gravityfed system of deep tunnels was devised by Thames Water Utilities Ltd; this involved a full ground investigation and underground obstruction survey to establish the optimum tunnel route, bearing in mind the many and various constraints.A series of shafts was sunk to connect directly into the ring main with the purpose of either introducing water at major water‐treatment works or acting as pumpout shafts at strategic locations around the capital.The tunnels and shafts were designed to be built in two phases. Phase 1 was constructed using conventional wedgeblock techniques, but problems were encountered which resulted in increased costs and delay.Phase 2 therefore necessitated a different approach. The company adopted a completely new strategy by changing the form of contract, purchasing its own tunnel boring machines, and redesigning the tunnel linings.One of the keys to the success of the ring main was the new expanded wedgeblock concrete lining. Design calculations were prepared and finite element analysis work was carried out. The new rings were subjected to build and load tests, both on individual segments and complete rings, using specially designed test rigs.
Commissioning and Operation of the Thames Water Ring Main
Authors: Edwards A.G. , Colbourne J. , Renton P. , Batchelor J.M. 
Published: July 2007

ABSTRACTIn order to achieve the earliest possible benefits of the investment in the Thames Water ring main, in late 1989 it was recognized that it was necessary to establish a commissioning team. The remit for the team was to progressively commission the ring main to match the construction programme, without risking the integrity of the daily water supply.This paper describes the methods, accountability, and achievement of the commissioning project.
Household Hazardous Wastes: Current Issues in the UK
Authors: Heaven S. , Kerrell E. 
Published: July 2007

AbstractAs collection programmes are now being established to manage household hazardous waste in the UK, it has become increasingly apparent that there is an urgent need for clear and consistent definitions. Also, from an assessment of definitions in current use in North America and Europe, it is evident that definitions are likely to be needed at a number of levels. This paper reviews current practice and offers some guidance on the development of definitions in the UK.