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Great Sankey, United Kingdom

Portfolio risk assessments (PRAs) have indicated that some dams built at the turn of the nineteenth century to supply water for the Rochdale canal are particularly vulnerable to internal erosion. The canal is served by a series of dams built between 1794 and 1857. United Utilities (UU), who now own the dams, have recognised that the PRA was a high-level screening tool, and that a more rigorous method was required to provide a more detailed assessment of all potential failure modes. This led to the development of a more robust approach using the unified method of risk analysis (internal erosion toolbox), which utilises a generic event tree approach to assessing potential seepage and piping failure paths. This paper describes some lessons learnt in applying the toolbox to canal dams. It identifies a number of issues that application of the toolbox posed and the research undertaken to overcome these in order to make credible assessments of probability of failure so as to identify dams with an unacceptable level of risk and to help UU to prioritise its capital expenditure on reservoir remedial works. The paper is in two parts: Part 1 consists of an introduction to the dams under consideration and the toolbox. It then considers how to overcome bias in estimation of the probability of initiation of internal erosion. Part 2 considers ways to assess the time for development and likely detection of internal erosion. © 2013 ICE Publishing: All rights reserved. Source

Eddleston M.,MWH | Gardiner K.D.,United Utilities
Managing Dams: Challenges in a Time of Change - Proceedings of the 16th Conference of the British Dam Society

United Utilities has been using Portfolio Risk Assessment (PRA) since 2002 to evaluate the vulnerability of their dams to piping and internal erosion. Remedial works have been proposed on a number of dams but the degree of risk reduction likely to be achieved by these works cannot be ascertained at Portfolio level. It was recognized that a method was needed to estimate dam performance before and after remedial works to justify the expenditure. Therefore UU engaged their engineering service provider, MWH, to research and develop a methodology based on event tree methods. Research by MWH in the UK and America indicated that the recently developed "Unified Method of Risk Analysis for Dam Safety" (referred to as a Toolbox) would provide the required methodology. The paper outlines UU's approach to risk assessment, summarises the history and the principles behind the Toolbox, and describes the experience of UU/MWH in using it on a trial dam. Source

Agency: GTR | Branch: EPSRC | Program: | Phase: Training Grant | Award Amount: 3.68M | Year: 2014

The UK water sector is experiencing a period of profound change with both public and private sector actors seeking evidence-based responses to a host of emerging global, regional and national challenges which are driven by demographic, climatic, and land use changes as well as regulatory pressures for more efficient delivery of services. Although the UK Water Industry is keen to embrace the challenge and well placed to innovate, it lacks the financial resources to support longer term skills and knowledge generation. A new cadre of engineers is required for the water industry to not only make our society more sustainable and profitable but to develop a new suite of goods and services for a rapidly urbanising world. EPSRC Centres for Doctoral Training provide an ideal mechanism with which to remediate the emerging shortfall in advanced engineering skills within the sector. In particular, the training of next-generation engineering leaders for the sector requires a subtle balance between industrial and academic contributions; calling for a funding mechanism which privileges industrial need but provides for significant academic inputs to training and research. The STREAM initiative draws together five of the UKs leading water research and training groups to secure the future supply of advanced engineering professionals in this area of vital importance to the UK. Led by the Centre for Water Science at Cranfield University, the consortium also draws on expertise from the Universities of Sheffield and Bradford, Imperial College London, Newcastle University, and the University of Exeter. STREAM offers Engineering Doctorate and PhD awards through a programme which incorporates; (i) acquisition of advanced technical skills through attendance at masters level training courses, (ii) tuition in the competencies and abilities expected of senior engineers, and (iii) doctoral level research projects. Our EngD students spend at least 75% of their time working in industry or on industry specified research problems. Example research topics to be addressed by the schemes students include; delivering drinking water quality and protecting public health; reducing carbon footprint; reducing water demand; improving service resilience and reliability; protecting natural water bodies; reducing sewer flooding, developing and implementing strategies for Integrated Water Management, and delivering new approaches to characterising, communicating and mitigating risk and uncertainty. Fifteen studentships per year for five years will be offered with each position being sponsored by an industrial partner from the water sector. A series of common attendance events will underpin programme and group identity. These include, (i) an initial three-month taught programme based at Cranfield University, (ii) an open invitation STREAM symposium and (iii) a Challenge Week to take place each summer including transferrable skills training and guest lectures from leading industrialists and scientists. Outreach activities will extend participation in the programme, pursue collaboration with associated initiatives, promote brand awareness of the EngD qualification, and engage with a wide range of stakeholder groups (including the public) to promote engagement with and understanding of STREAM activities. Strategic direction for the programme will be formulated through an Industry Advisory Board comprising representatives from professional bodies, employers, and regulators. This body will provide strategic guidance informed by sector needs, review the operational aspects of the taught and research components as a quality control, and conduct foresight studies of relevant research areas. A small International Steering Committee will ensure global relevance for the programme. The total cost of the STREAM programme is £9m, £2.8m of which is being invested by industry and £1.8m by the five collaborating universities. Just under £4.4m is being requested from EPSRC

O'Brien M.,Perceptive Engineering Ltd. | Mack J.,Perceptive Engineering Ltd. | Lennox B.,University of Manchester | Lovett D.,Perceptive Engineering Ltd. | Wall A.,United Utilities
Control Engineering Practice

This paper details a case study application of model predictive control for a wastewater treatment process in Lancaster, North England. The control system was implemented in real time, together with a plant monitoring system for the purposes of process supervision. Following implementation, the model predictive control system provided significant benefits compared with the previously applied control system. These benefits included a reduction of over 25% in power usage and a similar increase in plant efficiency. The system therefore represents a useful tool in helping the water industry to reach its goal of significantly reducing its carbon footprint. © 2010 Elsevier Ltd. Source

Santos A.,Cranfield University | Reif R.,University of Santiago de Compostela | Hillis P.,United Utilities | Judd S.J.,Cranfield University
Environmental Technology

The fate and removal of permethrin during conventional wastewater treatment were evaluated at pilot-plant scale at different concentrations of mixed liquor suspended solids (MLSS) and, hence, different solids retention times (SRT). At feed concentrations of 0.26-0.86 g L-1, the permethrin was removed by primary treatment at an efficiency rate of 37%, similar to previously reported data, and from 40% to 83% for secondary treatment, decreasing with decreasing SRT. Comparable ranges, from 37% up to 98%, have been reported for micropollutants with similar physicochemical properties to permethrin, such as galaxolide and tonalide. Little difference in removal was noted between the medium and low MLSS concentrations trials, the main difference in treated effluent permethrin concentration arising on changing from high to medium MLSS levels. This was attributed to the limited acclimatization period employed in these two trials, leading to higher levels of soluble organic matter in the treated water, with which the permethrin appeared to be associated. © 2011 Taylor & Francis. Source

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