Blair G.,Scottish Water |
Quigley J.,University of Strathclyde |
Walls L.,University of Strathclyde
Safety and Reliability: Methodology and Applications - Proceedings of the European Safety and Reliability Conference, ESREL 2014 | Year: 2015
We develop and evaluate a method to estimate the frequency of an asset failure when experience event data are available for multiple assets of a given type. Typically such data contains information on assets of mixed ages, operating in different environments and in many cases the number of recorded events might be few or even zero. Assets are known to have slow age-related degradation and we have access to engineering experts who are able to provide judgment about the degradation rates. An empirical Bayes method is developed to allow us to estimate the failure rates for an asset on a particular site by using the available observational data pool together with structured engineering judgment of the degradation rate for the asset type. Our method aims to address the challenges of asset pool heterogeneity and environmental conditions across sites. We describe our practical motivation which is informed by a real problem facing a water utility. We explain the principles and mathematics underpinning the new methods, before describing a simulation based evaluation of their accuracy. We show that the empirical Bayes methods provide accurate estimates of the failure intensities for a range of parameters considered in this controlled study and that empirical Bayes estimators can compensate for bias in initial judgmental assessments of degradation rates. We discuss how the method can be applied in the industry context. © 2015 Taylor & Francis Group. Source
Jarvis P.,Cranfield University |
Sharp E.,Severn Trent Water LTD. |
Pidou M.,University of Queensland |
Molinder R.,University of Leeds |
And 2 more authors.
Water Research | Year: 2012
Coagulation in drinking water treatment has relied upon iron (Fe) and aluminium (Al) salts throughout the last century to provide the bulk removal of contaminants from source waters containing natural organic matter (NOM). However, there is now a need for improved treatment of these waters as their quality deteriorates and water quality standards become more difficult to achieve. Alternative coagulant chemicals offer a simple and inexpensive way of doing this. In this work a novel zirconium (Zr) coagulant was compared against traditional Fe and Al coagulants. The Zr coagulant was able to provide between 46 and 150% lower dissolved organic carbon (DOC) residual in comparison to the best traditional coagulant (Fe). In addition floc properties were significantly improved with larger and stronger flocs forming when the Zr coagulant was used with the median floc sizes being 930 μm for Zr; 710 μm for Fe and 450 μm for Al. In pilot scale experiments, a similar improved NOM and particle removal was observed. The results show that when optimised for combined DOC removal and low residual turbidity, the Zr coagulant out-performed the other coagulants tested at both bench and pilot scale. © 2012 Elsevier Ltd. Source
Courtnadge K.M.,Postgate |
Muir A.,Halcrow Group Ltd. |
Sandilands S.,Scottish Water |
Martin J.,Halcrow Group Ltd.
Water Science and Technology: Water Supply | Year: 2010
Background: Granular activated carbon (GAC) and Brimac media has been used for many years in water treatment works to reduce and remove colour and total organic carbon (TOCs). This reduces the formation of trihalomethanes (THMs) formed by disinfection with chlorine. The TOCs arise from humic and fulvic acids found in source waters for many, small, scattered remote communities in Scotland. A number of different configurations and empty bed contact times (EBCTs) of GAC and Brimac media were studied at Scottish Waters Acharacle water treatment works using a purpose built pilot plant of flexible design. This was used to establish the absolute design threshold for colour and TOC to meet Scottish Water's water specifications for their removal. Results: The 50:50 combination of Brimac and GAC in series reduced raw colour of up to 39°Hazen to below 108Hazen and raw TOCs from up to 5.7 mg/l to <2.0 mg/l producing the lowest levels of THMs after chlorine addition of <10μg/l. An EBCT of 5.4 hours produced an average colour removal of 79.2% and average TOC removal of 79.1%. Conclusions: 50:50 Brimac then GAC in series with an EBCT of 5.4 hours was the best configuration for the removal of colour and TOCs and gave rise to the lowest formation of THMs. The trials have successfully proved how the THM precursors can be removed by the GAC once the colour has been removed by the Brimac. This has not only provided a design solution for Acharacle WTW but the "way forward" for Scottish Water with regard to media change out on their numerous existing GAC plants which are faced with similar problems. © IWA Publishing 2010. Source
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 1.19M | Year: 2014
This innovative interdisciplinary project aims to develop an easy-to-use, evidence-based resource which can be used in decision-making in drought risk management. To achieve this, we will bring together information from drought science and scenario-modelling (using mathematical models to forecast the impacts of drought) with stakeholder engagement and narrative storytelling. While previous drought impact studies have often focused on using mathematical modelling, this project is very different. The project will integrate arts, humanities and social science research methods, with hydrological, meteorological, agricultural and ecological science knowledge through multi-partner collaboration. Seven case study catchments (areas linked by a common water resource) in England, Wales and Scotland will be selected to reflect the hydrological, socio-economic and cultural contrasts in the UK. Study of drought impacts will take place at different scales - from small plot experiments to local catchment scale. Citizen science and stakeholder engagement with plot experiments in urban and rural areas will be used as stimuli for conversations about drought risk and its mitigation. The project will: (i) investigate different stakeholder perceptions of when drought occurs and action is needed; (ii) examine how water level and temperature affect drought perception; (iii) explore the impact of policy decisions on drought management; (iv) consider water users behaviours which lead to adverse drought impacts on people and ecosystems and; (v) evaluate water-use conflicts, synergies and trade-offs, drawing on previous drought experiences and community knowledge. The project spans a range of sectors including water supply; health, business, agriculture/horticulture, built environment, extractive industries and ecosystem services, within 7 case-study catchments. Through a storytelling approach, scientists will exchange cutting edge science with different drought stakeholders, and these stakeholders will, in turn, exchange their knowledge. Stakeholders include those in: construction; gardeners and allotment holders; small and large businesses; local authorities; emergency planners; recreational water users; biodiversity managers; public health professionals - both physical and mental health; and local communities/public. The stakeholder meetings will capture various data including: - different stakeholder perceptions of drought and its causes - local knowledge around drought onset and strategies for mitigation (e.g. attitudes to water saving, responses to reduced water availability) - insights into how to live with drought and increase individual/community drought resilience - the impact of alternating floods and droughts The information will be shared within, and between, stakeholder groups in the case-studies and beyond using social media. This information will be analysed, and integrated with drought science to develop an innovative web-based decision-making utility. These data will feedback into the drought modelling and future scenario building with a view to exploring a variety of policy options. This will help ascertain present and future water resources availability, focusing on past, present and future drought periods across N-S and W-E climatic gradients. The project will be as far as possible be open science - maintaining open, real-time access to research questions, data, results, methodologies, narratives, publications and other outputs via the project website, updated as the project progresses. Project outputs will include: the decision-making support utility incorporating science-narrative resources; hydrological models for the 7 case-study catchments; a social media web-platform to share project resources; a database of species responses/management options to mitigate drought/post-drought recovery at different scales, and management guidelines on coping with drought/water scarcity at different scales.
Agency: Cordis | Branch: FP7 | Program: CP | Phase: ICT-2011.6.3 | Award Amount: 4.65M | Year: 2012
Improving the efficiency of water management in Europe was recognised by the EC as essential for overcoming the growing exposure of European countries to Water Scarcity and Droughts. UrbanWater proposes a platform that will enable a better end-to-end water management in urban areas, accounting for 17% of freshwater consumption in the EU.\nThe project will undertake the development, demonstration, and economic up-scaling of an innovative ICT-based platform for the efficient integrated management of water resources. The system will benefit end-users, utilities, public authorities, the environment and the general public, in terms of: (i) providing consumers with comprehensive tools enabling them to use water more efficiently thereby reducing overall consumption; (ii) helping water utilities to meet demand at reduced costs; and (iii) fostering new partnerships between water authorities, utility, equipment and software companies so as to ensure the successful commercialisation of the system and the evolution of the European water sector as a global leader.\nThe system will incorporate advanced metering solutions, real-time communication of consumption data and new data management technologies with real-time predictive capability, demand forecasting, consumption pattern interpretation, decision support systems, adaptive pricing and user empowerment solutions.\nThe UrbanWater consortium includes ICT companies, research organisations, water utilities and authorities with complementary capacities and all the know-how required to oversee the successful completion of the project. Two water distributors included in the group will undertake large-scale validations with their urban users, thus promoting a final outcome that is close to the market and to the end-users.\nThe final outcome of the project will remain open and interoperable with energy and water management schemes, thus positively impacting not only water consumption, but overall usage of natural resources across Europe.