Interview with Sarah Bell

Sarah BellSarah Bell is an environmental engineer whose research relates to the sustainability of urban water systems. She is interested policy and social aspects of sustainability, and how they relate to new technologies and infrastructure. Her work addresses water efficiency, water recycling, green infrastructure and options for new water resources. Her ongoing research investigates how to engage communities in infrastructure design to meet needs for food, water and energy. She started her engineering career at an aluminium smelter in Australia, after studying environmental engineering and chemistry. Concerns about carbon emissions and the impact of the industry on climate change led her to a PhD in Sustainability and Technology Policy at Murdoch University. Her PhD research and early academic career focussed on sustainable agriculture and land management. Since joining UCL in 2005 she has returned to engineering and has led projects including the UCLoo Festival of alternative sanitation, and London 2062 which addressed the future of London. She has received awards for her teaching on the MSc Environmental Systems Engineering (RAEng Excellence in Teaching) and the Bachelor of Arts and Sciences (UCL Provost’s Teaching Award). In 2015 she was a British Science Association Media Fellow, covering science, engineering and the environment for Londonist. She is currently director of the UCL Engineering Exchange, which aims to improve engagement between local communities and engineering research.

Tell us about the water reuse project you worked on with Arup

We worked with engineering firm Arup to develop a decision support tool for non-potable reuse networks. The idea is to connect sources of relatively high quality wastewater, such as greywater from showers or laundries, to points of demand for non-potable water, such as for toilet flushing or irrigation. Household scale greywater reuse is relatively well established but connecting supply and demand of non-potable water with minimal treatment between users in different dwellings or buildings is less well known. A major challenge for such a scheme would be the cost and construction of new distribution networks, including local storage and treatment. The project developed an optimization model for designing networks to collect and distribute water of different qualities on a neighbourhood scale. My contribution was to develop a rapid appraisal tool to determine the social and political viability of the scheme prior to undertaking conceptual design and optimization.

What did the project achieve?

The project showed that the concept of non-potable reuse networks is feasible. We tested our tool in neighbourhoods in London and Birmingham and showed that it is possible for non-potable water networks to be economically comparable to conventional networks. Most existing non-potable water networks use municipal wastewater as their starting point, which requires a lot of treatment. By collecting and distributing greywater and other relatively clean sources of wastewater the treatment costs are vastly reduced.

What were some of the biggest challenges you faced during the project?

Optimisation techniques for water networks and resource management have been developing rapidly in recent years, thanks in part of advances in computing power. It is tempting to use these techniques to develop one big decision making model, to include all possible factors influencing water infrastructure decisions. We discussed the possibility of putting social, environmental and political factors into the optimization model, but decided against it. In developing a decision support tool it is important to make the process as transparent as possible, and there is a risk that in trying to quantify social factors we might have introduced bias into the model and made it difficult for users to really understand the assumptions and implications of the outputs. We decided to address social factors as a separate process to the economic optimization. This meant using the mathematical techniques to do what they do best, and leaving social and political factors more open to interpretation and debate.

Do you plan to follow up on this project in the future?

The interplay between numerical modelling and ICT based tools and social, political and management issues in decision support for water infrastructure is an ongoing theme in my research. My PhD students are working with different models and tools in Mexico City, Tehran and Nairobi, and we are building up good data and case studies to allow international comparison.

You work on the intersection of a number of fields. What are some of the problems of working with scientists from different fields?

I always struggled to settle for just one discipline, so working with people from different fields is  fun for me. The main problems I have encountered come from the fear of being misunderstood, more often than genuine misunderstandings. There are also difficulties in how different disciplines recognise and reward research outcomes. If researchers need to publish in specific journals to get recognition in their field then it can be difficult for them to engage in interdisciplinary work. For the most part the people I work with are curious enough to be willing to explore new territory between the disciplines, and we usually manage to work out the details later.

You write a blog and use twitter reasonably prolifically, both to express your personal opinions and talk about work that interests you. Do you find social media a useful tool in connecting with other engineers?

Social media is definitely helpful in making connections. I have projects with engineers in Chile which started out as interactions on twitter. For people at the beginning or middle of their careers it is a good way to get noticed by more senior people. Twitter provides a fairly informal way for people to get to know you and your work. But of course, it can be dangerous for those of us who are prone to procrastination.

Why did you decide to go into engineering?

I picked it out of a hat. As a teenager I couldn’t decide what I wanted to study at university so I wrote all the things I was interested in on small pieces of paper and randomly pulled out engineering. Provided you’ve got a decent set of options in the hat I think this is as good a method as any for choosing what to study. Engineering was in the hat because it used science and maths to solve problems and seemed like it could lead to interesting work. I left engineering for a while to do my PhD and early academic careers, but I am mostly pleased to be back. Some days it is exciting to be working in a field that creates future technologies and systems. Other days it is frustrating to work in a rather conservative profession. 

What are engineers doing at the moment that you think hampers our path to a more sustainable future?

Engineers like to think of themselves as problem solvers. The question is, whose problems are they solving? To create a more sustainable future defining the problem is at least as important as creating a solution. Engineers are sometimes too eager to give quick technological solutions without considering all the alternatives and repercussions. For instance, a lot of engineers seem to think that if we can find a limitless, cheap, zero-carbon source of energy all our sustainability problems will be solved. I think this could create more environmental destruction and social problems – energy prices are a key constraint on a lot of activities that could otherwise be harmful. We don’t necessarily want a new technology that will make it cheaper and faster to cut down rainforests or dig up every last ounce of gold, creating pollution and dangerous working conditions. Engineers too easily jump to big technological fixes instead of asking whether they are solving the right problem.

Is there one thing engineers could do quickly and easily that would make society more sustainable?

I don’t think so. Perhaps engineers need to slow down a bit and listen to a wider range of people rather than jumping in to invent the next big solution to a problem that hasn’t been properly defined. I think society could be more sustainable if engineers presented all the technical options available as openly as possible and engaged users and the public in deciding which option to implement.

Do you have a role model in engineering and why?

Sue Black is a great inspiration for women in tech. She is a computer scientist who was a single mum in her mid-twenties when she went back to night-school so she could get into university. She then went on to do a PhD and became Head of Department at the University of Westminster. More recently she ran the campaign to save Bletchley Park and has started TechMums to teach women IT skills and coding.

My academic hero is Jill Kerr Conway who started life on a sheep station in outback New South Wales and became the first woman president of Smith College in the US. Both of these women came from unlikely backgrounds to make a unique and powerful contribution in their fields and to society.

What’s your favourite phrase?

Sometimes it is better to apologise than ask permission.