Most water companies spend more than half of their total budgets to address the problem of rehabilitation. For example, the U.S. Environmental Protection Agency reported in 2001 that $151 billion would be needed for maintenance and replacement of drinking water systems in the USA over 20 years with 55% of this amount dedicated to pipelines. The proposed research addresses the problem of rehabilitation and long term planning for future upgrading of water distribution systems. Water distribution systems are an invaluable component of the critical infrastructure of urban populations worldwide. These systems need to be managed in a cost effective way while ensuring that key performance indicators and regulatory compliance criteria are not breached. The various requirements are extremely difficult to achieve because of their often conflicting nature and the sheer scale and complexities of water distribution systems. Optimization of water distribution systems is extremely challenging and the development of algorithms that are fast enough for routine use in industry is a most pressing issue.The optimal solutions of constrained optimization problems generally occur at the boundary of the feasible region of the solution space. The project will develop a radically different approach for dealing with constraints in evolutionary optimization algorithms for water distribution systems using head driven analysis. Head driven analysis provides the means to quickly and accurately identify the feasible region of the solution space and, more importantly, locate cost-effective solutions along its boundary without recourse to ad-hoc penalty functions. The application of evolutionary algorithms such as genetic algorithms to water distribution systems requires parameters such as the population size, crossover and mutation probabilities and a few empirical guidelines exist for the proper values of some of these parameters. However, information on how to determine suitable values of the penalty factors used to convert the typical water distribution system constrained optimization problem into an unconstrained optimization problem solvable by evolutionary algorithms is extremely scarce. In general the value of a penalty parameter is currently determined by trial and error. This is the principal issue to be addressed in this project, by developing a procedure which does away with the penalty parameter altogether. The goal is to develop fast evolutionary algorithms for use in industry on a routine basis.

The resilience of water systems in the context of climate change, weather extremes, planning and operational decisions is crucial for water infrastructure service delivery and environmental management. In the UK, water systems are under extreme pressure from exceptional droughts like in the summer of 2022, or challenges to manage sewage spills. At the same time, the latest report on river water quality shows that only 14% of rivers in England meet good ecological status. Thus, there is a need to develop resilience assessments to address interlinked challenges of water systems and the environment. This project addresses a critical knowledge gap: What are resilience scenarios for integrated water systems (RIWS) that can be used to evaluate resilience metrics for various stressors, across system components and to inform adaptive planning? The development of RIWS will be supported by the novel Water System Integration Modelling Framework (WSIMOD) developed at the Imperial College London that will be integrated with the DAFNI platform. WSIMOD's flexibility in integrating numerous water system interactions (rural-urban, water supply-wastewater and flow-water quality) and representing a range of water management options with fast simulations times using primarily publicly available data outstand it as an ideal modelling tool for assessing the resilience of integrated water systems. Novel resilience metrics that combine concepts of a critical threshold in performance data with performance metrics evaluation will be informed by Greater London Authority, Thames and Affinity Water and Environment Agency's engagement through participatory workshops. Stressors will be defined as acute (e.g., component failure) and chronic (e.g., climate change) disruptions. The RIWS project aims to develop scenarios that can provide evidence for water companies, planning authorities and environmental regulators on the feasibility of water systems adaptive planning when assessed by resilience metrics, such as structural options (e.g., wastewater treatment plant upgrade) or coordinated operational decisions (e.g., water supply and wastewater systems information exchange to manage river water quality). The project directly contributes to the 'Building a secure and resilient world' strategy focus on 'adaptation to change and robust decision making' and place-based resilience of integrated rural-urban water systems.

Groundwater turbidity above the drinking water limit is a common problem in groundwater supply boreholes that abstract from fractured aquifer systems, such as the Chalk in South East England. Strategies for managing such high turbidity events include blending or filtering the water or temporarily shutting down affected wells or borehole isolating borehole sections, which costs water companies and their customers several 10th of Millions of Pounds every year. While the source of turbidity can vary, the occurrence of turbidity spikes is usually associated with fast groundwater flows through fractures following prolonged rainfall or intensive storm events. The occurrence of such high turbidity events can currently not be predicted, posing a severe financial risk to water companies and limiting the reliability of the available groundwater resource. This project aims to develop an in-borehole monitoring system for continuously observing fracture inflows in boreholes and assessing their linkage to turbidity events. The system is based on Active Distributed Temperature Sensing (A-DTS) technology which uses fibre-optic cables installed in boreholes to continuously monitor the temperature changes within boreholes under ambient temperature conditions and in response to heat pulses, induced by heating a metal core within the cable. The project will therefore: 1. Demonstrate the suitability of A-DTS technology for quantifying in-situ fracture flow to groundwater boreholes. This will include testing different technological setups and monitoring strategies across a range of conditions and validating A-DTS technology against the results of traditional non-continuous borehole characterisation methods. 2. Develop a continuous A-DTS based early warning system of changes in fracture flow and turbidity. Therefore, in long-term (12 month) continuous monitoring of fracture flows additionally turbidity and electrical conductivity (EC) at different depths within the borehole will be monitored. 3. Identify Risk Zones for Borehole Turbidity by developing and applying numerical modelling tools to simulate groundwater (and suspended particles) flow through the subsurface under variable operational and meteorological conditions. This will allow the delineation of the most likely water and particle pathways and the mapping of risk zones that are most likely to deliver particles, and hence turbidity, to the investigated boreholes. The outputs of this study will directly benefit water companies by providing novel tools for identifying and characterising turbidity risk zones within and around existing supply borehole infrastructure. This will inform the design and implementation of risk amelioration measures and will also influence decision on locations, design and operation of new groundwater supply boreholes. The continuous A-DTS monitoring system will provide early warning of imminent turbidity events, providing water companies with an opportunity to adjust operation of their infrastructure prior to the event and thereby reducing the overall impact on their operational and supply infrastructure, hence saving costs for the operators as well as their customers. Modelling tools developed in this project will support the delineation of risk zones for groundwater contamination and thus, not only impact on the management of water resource infrastructure but also on surface infrastructure design, management and operations. Furthermore, the technology also has potential applications in the assessment of salinisation risks (e.g. by identifying and delineating risk zones within and around supply boreholes) as well as for detecting possible impacts of hydraulic fracturing operations on the groundwater flow regime (e.g. through identification of flow regime changes/ new fractures within existing boreholes). Keywords: turbidity, risk, groundwater supply, A-DTS, monitoring, early warning system, water industry, customers, fractured aquifers

Groundwater is a hugely important natural resource, providing the majority of drinking water globally, some 35% of drinking water in the UK, and up to 80% in southern England. High frequency real-time systems are now widely used in water industry for water quality monitoring, however transient microbiological contamination is currently still monitored using traditional spot sampling and culturing techniques. The highly dynamic nature of microbiological contamination necessitates high frequency on-line monitoring for the optimisation of down-stream processes such as treatment and distribution. We propose to pilot and embed within the UK water industry the use of new fluorescence sensors to enable this. In addition, while it is generally understood that high levels of faecal contamination in groundwater may be accompanied by relatively high turbidity, this is often not the case, and depends on the source and pathway of faecal contamination in the subsurface. Differentiation of turbidity derived from aquifer material or induced by pumping and that derived from microbial contaminants has significant potential benefits to the water industry through treatment process optimisation. Water companies in England and Wales have invested £42 million on investigations into source water characterisation and treatment process optimisation from 2010 - 2015 (OFWAT 2009) but understanding transient microbial contamination remains a significant challenge. Recent NERC funded research on in-situ fluorescence spectroscopy, now a well-established technology, offers a highly sensitive method to achieve this for raw groundwater sources. Through a partner led process we have developed a proposal to pilot, embed and develop an implementation strategy for this technology that is relevant for the UK water industry, but is also highly relevant for international water and health sector organisations. As part of this proposal, placement activities within two UK water companies (Affinity Water and Wessex Water) will be carried out to i) pilot and embed the use of tryptophan sensor technology in the UK water industry for improved monitoring of microbiological contamination in vulnerable groundwater sources, ii) provide robust evidence on the suitability of the current turbidity trigger (1NTU) for groundwater quality assessments, iii) provide an implementation strategy for this technology within the UK water sector through user-led collaboration. This will be carried out though visits to all UK water companies to obtain feedback on how this could benefit and be implemented in different parts of the water sector and disseminate findings with potential new end users. Working with key partners from across the UK water industry, including water companies (Affinity Water and Wessex Water) and cross-sector organisations (UKWIR, Water UK and DWI), TryGGER aims to embed within the UK water sector the use of on-line sensors for monitoring dynamic microbiological contamination in groundwater sources for improved use of water resources and optimisation of treatment processes. The application of this sensor technology will be piloted in four case study sites in the UK, through placement activities undertaken by BGS scientist in water industry partners. These have been selected in consultation with water utilities to be representative of vulnerable groundwater settings, with wide applicability both within the UK context and globally. Importantly, a strategy for implementing the use of these sensors for raw water quality monitoring will be developed with end users from across the UK water industry as part of this proposal to enhance wider uptake of this technology. This proposal has the potential for far reaching impact in the UK water industry and further afield. Involvement of the main players in the water industry, as well as utility firms, from early on during proposal development this has ensured that is highly relevant to the end-user community.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.