The aim of this work is to develop a new test to monitor the formation and breakage of particles in water treatment processes. Before water reaches a customer's tap, it must pass through a train of processes to remove the impurities from the water before it is safe to drink. The bulk of the contaminants are removed from the water in the process of coagulation and flocculation. Here, a destabilising chemical, such as an iron or aluminium salt is added to the water which enables dissolved, colloidal and particulate material to aggregate into large, fragile particles called flocs. In most water treatment plants in the world, these particles are removed by a sedimentation or flotation process. Any fine residual particles remaining are then usually removed by a sand filter. Failure to remove these particles results in high turbidity in the filtered water, which can reduce the efficacy of disinfection and the particles can be a vehicle for more toxic compounds entering drinking water. For this reason, turbidity in drinking water is strictly controlled. In the UK, a target value for turbidity in drinking water is 1 nephelometric turbidity unit (NTU). Recent revision documents from the European Commission indicate that this will soon move to a mandatory value of 1 NTU, with a target value of 0.5 NTU.The properties of the floc particles that form has a strong influence on how well they are removed by the clarification and filtration processes. If the flocs are too small or break apart too easily, water quality is compromised. The composition and structure of the floc is a function of a number of factors, including the source water matrix, the coagulant and flocculation chemicals used and the mixing regime deployed. Measuring the character and the strength of the flocs can therefore provide some very useful information on how well they may be removed in water treatment systems. To date, floc strength tests have concentrated on characterisation of large scale floc breakage products. This can significantly underestimate the concentration of small particles in a heterogeneous system containing a wide range of particle sizes. However, it is the small particles (normally centred around 1 um for most filtration conditions used in practice) that can cause operational difficulties because they are least well removed in a filter. The intellectual contribution of this work is in developing an operationally applicable and relevant floc strength test that integrates particle size and particle removal in depth filtration. For the first time we will investigate floc strength in terms of the formation and concentration of small particles before and after floc breakage by measuring floc strength in terms of the small particles around 1 um. The project will therefore deliver a methodology to determine floc strength through understanding the formation of problem particles. In addition we will establish how the system water quality and coagulation conditions influence floc strength and the formation of particles that cause turbidity in drinking water. Finally we will develop coagulation control strategies to limit the formation of FBP to enable longer filter run times and more effective filtration which could be applied on full-scale water treatment systems.

In the UK, the sewer system is ageing, poorly monitored and around 300,000 km long. The system is subject to increasing capacity demands because of increased urbanisation, more stringent environmental regulation and the consequences of climate change in the form of more frequent and intense rainfall events. OFWAT, the economic regulator for the water industry, imposes a legal duty on water companies to maintain the structural and operational conditions of their sewer systems and also to progressively reduce flooding incidents from sewers. In 2004 OFWAT identified 5700 sewer flooding incidents and an additional 11600 properties with a 10% annual risk of flooding. In approximately 90% of these cases, flooding was caused by an obstruction in a section of sewer pipe. Consequently, monitoring pipes for obstructions and then rapidly removing them could form an important part of an effective programme to reduce sewer flooding. The aim of this project is to develop novel acoustic technology (sensor and software) to produce a near market prototype that can be used in a live sewer to measure rapidly and objectively in-pipe condition and identify blockages and damage. Sewer monitoring is currently limited to the interpretation of CCTV pictures or the use of LightLine surveys. These methods require a mobile trolley with camera to be inserted and travel up a pipe section acquiring images which are then manually examined and defects/obstructions classified according to the standard Sewer Rehabilitation Manual document. Discussions with sewer operators in the UK indicate that they CCTV survey around 2% of their networks every 5 years. This project will develop an alternative fast method for analysing objectively the condition of a sewer and locating blockages. Recent research at the University of Bradford (EPSRC grant EP/D058589/1) has proved that the area of pipe blockage, extent of cracks, water level and positions of lateral connections can be measured in the laboratory pipes using an acoustic method of inspection. In this way the pipe condition of a sewer could be determined between manholes in the airborne regime. The key element of this acoustic device is a small multi-sensor array and advanced, real-time signal processing algorithm which overcome the effects of ambient noise and reverberation in the manhole environment. The key barriers to transferring this technology to the commercial sector are: (i) construction of an intrinsically safe, robust instrument; (ii) acquisition of sufficient field data to demonstrate clearly to potential users that acoustic sensors can reliably identify defects and obstructions in sewers (iii) demonstration that the acoustic technology can provide data that is compatible with the conventional CCTV methods and can be mapped onto the existing sewer condition classifications and sewer databases used by UK water companies. The data collected in the field will be critical in determining the nature and extent of the industrial funding and commercial interest from potential stakeholders. The investigators are in contact with four commercial organisations who support this work: Richard Long Associates, Mouchel Parkman, Yorkshire Water Services and Thames Water. It is generally agreed that CCTV surveys take between 2 and 4 hours per 100m length for measurement with a similar time for image analysis. This costs between 2 and 40 per linear metre depending on the access constraints. Acoustic measurement potentially reduces the measurement and analysis time to tens of minutes per 100m. Significant efficiencies can be achieved. This would enable operators to survey more of their network more frequently so would allow for better monitoring strategies to be developed, the earlier identification of defects and especially blockages leading to fewer flooding incidents and better planned maintenance.

The problem: The use of engineered nanoparticles (NP) in cosmetics, pharmaceuticals, sensors and many other commercial applications has been growing exponentially over the past decade. Because of their increasing application many NP are discharged to the watercourse both by industrial companies and through domestic use. The technology for monitoring the environmental impact of these materials, particularly in aquatic systems, is not well developed. It is not only sufficient to be able to determine the NP in water but also it is crucial to have some understanding of their toxicity or biological activity. At the same time, a high throughput screener is urgently required to report on the biomembrane activity (ability to bind to/adsorb on/penetrate biological membranes) of different NP and/or products containing NP dispersed in water. A screening system for NP is therefore required which reports routinely on the level of biologically active NP in raw, waste and drinking waters. At the same time the presence of heavy metal ions in water is always a concern due to their implicit toxicity. These heavy metal ions can be derived from industrial and/or domestic use and in spite of the tremendous advances in the analysis of heavy metal ions in water in the past 50 years, there is currently no routine heavy metal ion screener available for natural and potable waters. A combined NP and heavy metal ion screener therefore would have immediate application in any organisation concerned about the quality of water which comes into contact with human activity. Addressing the problem: The proposed technology offers a device which has a dual capability as follows: (1) To screen waters for NP which are biomembrane active and hence are putatively toxic and, (2) To detect toxic heavy metal ions (Cu2+, Pb2+, Cd2+ and Zn2+) in water. The system can also be used to test samples of NP or products containing NP dispersed in water for biomembrane activity. The screening for NP in water is rapid, on-line and high throughput and takes 10 minutes to test each sample. Similarly heavy metal ions in the water can be measured together simultaneously and quantitatively. The NP screener works by looking at the interaction of NP with a phospholipid layer coated on a chip based Pt/Hg microelectrode in a flow cell. This is a development of a previous technology which uses the same device to screen waters for biomembrane active compounds. The heavy metal ions are determined using anodic stripping voltammetry which is a well established analytical technique. The development of the chip-based Pt/Hg electrode in flow cell with flow injection techniques enables both techniques to be used in a high throughput configuration. The switchover from one technique to the other can be readily software controlled. Benefits which end-users will derive by adopting it: (1) Screening waters for the presence of biomembrane active NP (2) Screening products containing NP dispersed in water for biomembrane activity (3) Screening commercially produced NP dispersed in water for biomembrane activity (4) Detecting, identifying and quantitatively measuring toxic heavy metal ions in water

Yorkshire Water (YW), Scottish Water and Dwr Cymru Welsh Water (WW) have extensive networks of clean/waste water pipes made of a variety of materials (ferrous, plastics). It is recognized that pipe failure occurs through a complex set of interactions including corrosion, factors such as geohazards (ground movements), environmental factors (e.g. slope) and other external factors (e.g. traffic vibration, surge demand). When these failures occur it results in loss of supply to properties, causes public highway closures and potentially long-term inconvenience to business and the general public. Changing ground moisture and thermal profiles caused by environmental change may enhance the probability of drought or flooding. In particular, this may increase the impact of ground conditions on the pipe network, exacerbating future failures (causing asset loss, exfiltration undermining of infrastructure and contamination). Increased leakages, particularly in drought years are a potential major concern to the regulator, OFWAT. This project aims to help water companies manage the repair and maintenance of their pipe networks through the development of a spatial model relating pipe failure data to a range of environmental, geohazard and external factors. The model will provide evidence about the primary factors in pipe failure which water companies can use to improve pipe network infrastructure management and resilience within a changing climate. These outputs can be used by water company engineers (i) to provide information regarding pipe failure that can be used to improve design standards for different pipe materials (e.g. plastic, ferrous, concrete) and installation, (ii) to be used as a screening tool to identify areas where additional factors not related to model covariates are causing high incidences of pipe failure and (iii) to identify areas where additional engineering solutions can be used to build climate resilience into the network, particularly in relation to those geo-hazards most influenced by climate (e.g. shrink-swell clays). The proposed work includes a scoping study and exemplar of how those outputs can be delivered to the for water companies. Advice on functionality and content will be sought from YW and WW. Options include the possible integration of outputs into existing company systems or a stand-alone web based system. The output data could be presented as maps, GIS layers or digital services and will be based on significant model covariates presented as individual factors (GIS layers) or combined maps and hazard information. If a web based system is considered preferable we will provide an exemplar service to the water companies demonstrating how their data may be accessed either on a public good basis (via a public portal such as UKSO.org) or via a secure service to commercial users (secure web map services). Keywords: pipe network, water leakage, geo-hazards, spatial model,

The water industry faces intensifying risks to its water treatment systems through rising dissolved organic matter (DOM) concentrations, especially in upland raw water supplies which provide 70% of the UK's drinking water. Rain and meltwater percolating through soils transports DOM to reservoirs. The water industry has to restrict DOM concentrations to minimise taste and odour problems, reduce the potential for algal growth, and prevent the generation of potentially harmful levels of disinfection bi-products, formed from reactions between DOM and chemical disinfectants. DOM concentrations are increasing primarily as a result of an increase in soil organic matter solubility in response to regional reductions in atmospheric pollutants to soils. However, DOM levels in upland waters are also sensitive to variation, and long-term change, in soil temperatures, amounts and intensity of precipitation, the ionic strength of soil waters, the residence time of reservoirs, and seasalt deposition events during winter storms. The influence of these climate-related effects is increasing as organic matter continues to become more soluble. Currently, the primary industry approach to reduce DOM concentrations is the application of coagulant to precipitate the organic matter from the water, but additional filtration may also be required to remove DOM compounds that are less sensitive to this chemical effect. Both processes have a significant carbon footprint and are estimated to have already cost the industry hundreds of millions of pounds through the installation of new equipment where existing infrastructure was no longer able to deal with rising DOM concentrations. There is a pressing need, therefore, to foster a Climate Change Resilience Community that will combine the extensive expertise of the research and industry communities in the UK in order to address this challenge. FREEDOM-BCCR will develop an entirely new approach to understanding, managing, and planning responses to DOM increases in response to climate change. The community will provide the basis of support for decision making and will deliver adaptive (e.g. infrastructure investment) and mitigative (e.g. land-use interventions) approaches with which to build resilience in the upland water supply. We will augment the capability of a prototype Decision Support tool (DSt), developed by the current NERC FREEDOM Project with support from for Scottish Water, by incorporating catchment-specific climate change projections, predictive models and industry knowledge. This development of the FREEDOM DSt will fill critical knowledge gaps in model functionality including climate change impacts on soil and in-reservoir processing of DOM. We will define operational thresholds for DOM quantity and quality across the treatment chain and combine these to produce forecasts, at a UK scale, of DOM risk to drinking water supply. Proposed activities and respective Work Packages include: generation of UKCP18-based climate change projections using Hydro-JULES downscaled to specific catchments (WP1); Coupling of downscaled climate predictions with catchment and lake/reservoir models to explore the potential impact of climate change in influencing seasonal variation in DOM quantity, quality and vertical distribution in priority intensively monitored drinking water reservoirs and their catchments (WP2); validation of predictions of DOM quantity and quality produced by the FREEDOM DSt, beyond the parameterisation data set from Scottish Water, using hind-casting informed by wider UK industry data (WP3); upscaling application of the FREEDOM-UK DSt to provide predictions of the effects of climate change, land-use change and air pollution scenarios on DOM quantity and quality in other regions of the UK (WP4); and, foster the FREEDOM Climate Change Resilience Community focussing on co-development, application, and show-casing the FREEDOM-UK DSt through a programme of knowledge exchange activities (WP5).