Adapting Hybrid Green-Blue-Grey Infrastructure (GBGI) Approaches for Better Wastewater Processing
RECLAIM Network Plus funded a workshop on the 27th June at the University of Surrey focusing on integrating green, blue, and grey infrastructures for better wastewater processing and management to enhance sustainability, protect ecosystems, reduce energy consumption, and achieve the water industry's carbon net-zero target.
Workshop Blog Content
Urban water cycle involves multiple infrastructure segments, from drinking water treatment to sewage treatment and storm overflow management. Increasing water demand and aging infrastructure pose significant challenges to water security and safety. Sewage treatment works (STWs), the “gut of the community,” play a critical role in purifying pollutants and returning clean water. Traditionally classified as “grey infrastructure,” STWs are often designed and operated separately from other water infrastructure sections. However, integrating green infrastructure can protect ecosystems, enhance sustainability, and reduce energy consumptions, while grey infrastructure provides efficient and effective management. Adopting a combined Green-Blue-Grey Infrastructure (GBGI) approach is essential for sustainable urbanisation and improving quality of life, helping the water industry achieve its carbon net-zero target by 2030.
This one-day workshop organised and hosted by University of Surrey, which was enlightening and collaborative featured experts from Thames Water, Southern Water, Mott MacDonald, University of Surrey, UK Centre of Ecology & Hydrology (UKCEH), South East Rivers Trust, and Water Rangers. The day was meticulously planned to ensure a comprehensive understanding and interactive engagement with the GBGI concept. Here’s how the day unfolded:
Photo: Prof Prashant Kumar (from University of Surrey) giving the opening talk
Opening Session
Welcome Address: Reclaim Network Plus PI, Prof Prashant Kumar (from University of Surrey) delivered an inspiring opening talk on the RECLAIM network and overview of projects & events completed to date, setting the stage for the day's discussions.
Expert Presentations
The workshop delivered 8 presentations from both industry and academic experts in total.
In the morning session, Dr Bing Guo (from University of Surrey) raised the question of water challenges in the era of Net Zero and One Health, which enlightened the audience with collaborative and systematic thinking. Dr Michael Hutchins (from UKCEH) gave a case study of modelling river eutrophication in mixed-land use basins and quantifying benefits of riparian canopies as a natured-based solution. Craig Boorman (from Thames water) articulated Thames Water’s (the UK's largest water and wastewater services provider) water system perspective via understanding root causes and getting the right solutions, and summarised a key take-away message to all participants:
“If we don’t truly understand the root cause, we risk undermining confidence in the effectiveness of green-blue infrastructure, by implementing the wrong solution that does not achieve the intended outcome, representing poor investment of customers money”
Dr Lewis Campbell (from South East Rivers Trust) followed up with the talk explaining the role of the Rivers Trusts and Catchment Partnerships in the UK water sector, together with inspiring case study of water quality and biodiversity monitoring of the Upper Mole catchment.
In the afternoon session, Dr Nick Mills (from Southern Water) talked about how Southern Water implemented a holistic and sustainable approach to reduce the use of storm overflows, especially via AI and enhanced analysis to understand the dominate cause for storm overflow activation, so that the company could target the right approach and solutions. Dr. Ralitza Nikolova-Kuscu (from Mott McDonald) then explained the development of process selection tool for Nature-based Systems for Scottish Water, to improve the efficiency of the pre-feasibility design stage with short-listing potential options. This was followed by Prof Barry Lloyd who elaborated the hydraulic design, optimisation and evaluation of lagoons as a tertiary polishing stage at a Southern Water's STWs. Kat Kavanagh (from Water Rangers) then ended the expert presentation sessions with a delightful and inspiring demonstration how the NGO build community tools for proactive collaboration in water quality monitoring and education.
Photo: Speakers presenting their talks
(a) Dr Bing Guo (from University of Surrey);
(b) Dr Michael Hutchins (from UKCEH);
(c) Craig Boorman (from Thames Water);
(d) Dr Lewis Campbell (from South East Rivers Trust);
(e) Dr Nick Mills (Southern Water);
(f) Dr Ralitza Nikolova-Kuscu (Mott McDonald);
(g) Prof Barry Lloyd (University of Surrey);
(h) Kat Kavanagh (Water Rangers)
Interactive Sessions
Panel Discussions and Q&A Session:
Between the morning and afternoon presentation sessions, the speakers were invited to join a Panel Discussion, which engaged dialogues between participants and experts, focusing on challenges and best practices to integrate green, blue, and grey infrastructures in wastewater process and management. Both the experts panel and the audience raised various insightful recommendations to promote and enable holistic thinking and system approaches in wastewater management, including more evidence-based policy making, assessing multiple benefits of GBGI, engaging and collaborating with all stakeholders, and promoting more applied research (collaboration and funding application with industry), etc.
Photo: Panel discussion with experts
Group Activity of “Co-creation of system approach for wastewater processing”:
The final session of the workshop, all participants embarked on a journey to tackle the pressing issue of PFAS (Per- and polyfluoroalkyl substances) removal from water and wastewater. This group activity was not just a technical exercise but a comprehensive dive into understanding and addressing the multifaceted challenges surrounding PFAS.
Participants were divided into two groups, each tasked with practicing a system approach to address the focal problem: the removal of PFAS from the water/wastewater cycle. The exercise was designed to encourage holistic and systematic thinking, moving beyond traditional silos to consider a wide array of influencing factors.
Both groups began with a brainstorming session, identifying various factors that impact or are impacted by PFAS in the water/wastewater system. These factors spanned technical, social, economic, political, and ecological domains. This thorough exploration ensured that no stone was left unturned, acknowledging the complexity and interconnectivity of the issue at hand.
The consolidated factors that directly influence or are influenced by PFAS were then meticulously mapped to the focal problem. This mapping process allowed participants to visualise the intricate web of interactions and dependencies, providing a clearer picture of the systemic nature of PFAS contamination and its remediation.
Photo: Group Activity - Co-creation of system approach for wastewater processing
Photo: Group Activity – Group One discussion
Photo: Group Activity – Group Two discussion
Each group selected representatives to present their findings and system maps. These presentations were not just about sharing outcomes but also about learning from each other’s perspectives and approaches. The diversity in thought processes and solutions highlighted the richness of collective brainstorming and the value of varied viewpoints.
The session concluded with a sense of accomplishment and enriched understanding. Participants appreciated the opportunity to think holistically and systematically, learning how to integrate multiple factors and disciplines into solution optioneering. The exercise underscored the importance of a comprehensive approach to complex environmental problems, where technical solutions must be aligned with social, economic, political, and ecological considerations.
Photo: Group Activity – Participants presenting the group discussion outputs
Closing Session
Summary and Reflections: Dr Bing Guo and Xiaobo (Agnes) Shen gave a recap of the day’s key points and discussions.
Acknowledgments: University of Surrey would like to thank RECLAIM Network Plus for sponsoring the event; the speakers who delivered insightful talks to the audience, enhancing our understanding of the complex urban water cycle; and to all who participated the event in person. We would also extend our gratitude to Bing's PGR students and post-doc research fellows for their excellent volunteering work in hosting the event.
Workshop Takeaways
The workshop successfully achieved its aim of bridging stakeholders and co-designing optimised future hybrid GBGI solutions. The key outputs from the event include:
· Innovative GBGI Designs & System Approach: Participants developed overall understanding of the importance to integrate green, blue, and grey components to enhance wastewater processing and urban water quality.
· Collaborative Network: The event fostered a collaborative network of professionals from various sectors, and bridged academia with industry to identify potentials of collaborations in wastewater hybrid GBGI approaches.
· Knowledge Exchange: Attendees gained valuable insights into the complexities of the urban water cycle and the benefits of a hybrid GBGI approach, equipping them with the knowledge to advocate for and implement these solutions in their communities.
The "RECLAIM Network Plus Workshop: Adapting Hybrid GBGI Approaches for Better Wastewater Processing" was a significant step towards a sustainable urban water future. By bringing together diverse stakeholders and facilitating the co-creation of innovative solutions, the workshop highlighted the potential of GBGI to transform wastewater management, enhance urban resilience, and improve quality of life. As we move forward, the collaborative efforts and insights gained from this event will be instrumental in achieving a carbon net-zero water industry by 2030.
This workshop has been supported by the UKRI-funded RECLAIM Network Plus grant (EP/W034034/1).
By Xiaobo (Agnes) Shen and Dr Bing Guo, University of Surrey