Managing biofilms and disinfection residuals to protecting drinking water safety

The use of full scale pipe loop facilities under different and changing disinfection regimes will be central and essential to addressing the aims of this research.

The pipe loop facilities will recreate the physical (surface to volume ratio, hydraulic including shear stress and turbulence exchange) chemical (representative final water quality and change in residual) and biological (natural inoculum) conditions of operational systems such that the resulting understanding is meaningful and applicable.

A typical experiment programme for a given pipe loop facility would be:

1. Develop the biofilm for a given disinfection regime.
2. Change the disinfection regime from chlorine to chloramination to investigate the impact of change on eth biofilm.
3. Annual 'shock' loading of free chlorine to evaluate control of nitrifying bacteria. This is often used in US systems intended to alleviate the nitrification problems that can occur in the longer term in chloraminated systems (Option / selected Chloramine regimes only).
4. Characterise the biofilm and bulk water microbiology under different chlorination regimes and it's response to hydraulic changes, i.e. it's adhesion, trapping and release properties that influence water quality in distribution, etc.
5. Characterise the planktonic phase and overall bulk water quality both prior to and post changes to disinfection regimes
6. Investigate links to carbon levels (TOC/AOC) and adhesion / release properties with particular regards to changing disinfection regimes

It is anticipated that one of the pipe loops will be located on a site where a disinfection change is planned as part of operational practice. Results to be compared and contrasted between pipe loop and operational network to confirm applicability of resulting knowledge.

Graduates from the WRIC programme will produce new knowledge across the disciplinary landscape and graduate to occupy professional roles of influence and authority which require a thorough understanding of the pathways by which knowledge and technology are adopted and put to socially significant use. The people and knowledge delivered through the CDT will improve the efficiency and effectiveness of the nation's >£5bn annual spend on water and water related infrastructure (OFWAT, 2017), improving its resilience and securing its value for society for generations to come. With ambitions to nurture domain experts who can flourish at the interfaces of scientific disciplines and economic/industry sectors, the impact imperative is a significant but stimulating challenge for the WRIC CDT. Our impact strategy seeks to; (i) ensure rapid dissemination of scientific insights, (ii) maximise awareness and uptake of research sponsored through the CDT, and (iii) improve professional and lay understandings of the water infrastructure challenges facing society and the science behind candidate solutions. This strategy has been developed with project and Centre stakeholders so as to leverage additional resources, and maximise impact.
Improving the resilience of water infrastructure systems will be of benefit to a wide range of stakeholders. Given the CDT's bold intention to tackle knowledge gaps at the interfaces between disciplines and problems, new scientific understandings generated through WRIC will be of value to the knowledge users in the public sector (local authorities, regulators) and private sector (utilities, consultancies, technology providers), ultimately benefiting both lives and livelihoods across the UK and beyond. The UK economy will benefit from robust and resilient water infrastructure, in-line with the UK Government's Industrial Strategy for cleaner economic growth, the efficient use of resources, and building a regenerative circular economy. In the next Price Review PR19 (2020-25), water companies will be financially rewarded for implementing enhanced system resilience and innovation. Research outputs from WRIC will enable water companies to be able to meet these demands, alongside ambitious industry targets for zero water and wastewater quality failures, demand reduction and chemical recycling (OFWAT, 2017; UKWIR, 2017). These developments will facilitate inward international investment, development of new technology providers and supply chains, and opportunities for exporting intellectual property and know-how worldwide, further benefiting the UK economy. Project partners, including Thames Water, Severn Trent Water, Atkins, Stantec, Datatecnics also benefit from access to high quality graduates and facilities. Furthermore, regulatory agencies (Environment Agency, Drinking Water Inspectorate) and the European Commission will see benefits from improved compliance to regulations and sustainability agendas (Water Framework Directive 2008/32/EC and Drinking Water Directive 2017/0332(COD)).
The CDT programme will benefit the UK Collaboratorium for Research on Infrastructure and Cities (UKCRIC) government investments (£138M). Sheffield, Cranfield and Newcastle Universities have all received capital grants through UKCRIC to fund industrial scale test facility and observatory facilities to form an Urban Water Hub. The CDT will supply the resources to use and maximise the benefits and outputs from these facilities. Cooperation with other UKCRIC CDTs will help students better understand contemporary challenges for infrastructure and cities will catalyse horizontal innovation transfer and elevate the transformative potential of WRIC graduates.