We work across the whole sanitation service chain, from the toilet to treatment and reuse, and across the technical, financial, institutional and political decisions that decide whether a city's waste protects its people or harms them. The work reaches from Leeds into national sanitation planning across the global south, into a Lancet Commission reshaping global WASH policy, and into questions of water poverty much closer to home.

For seventy years, sanitation planning defaulted to one answer: sewerage. Sewers are expensive, slow, and in most fast-growing cities of the global south they serve only the old centre. Everyone else, the large majority, relies on pit latrines, septic tanks and on-site systems that no one planned, funded or emptied safely. The waste of millions was, in effect, invisible to the institutions meant to manage it.

Our research made it visible, and the argument has moved on since. Three convictions now drive this work. First, that sanitation is a problem of systems, evidence, finance and politics at least as much as engineering, and that progress comes from giving decision-makers an honest picture of an entire city and helping them act on it. Second, that the sector's long focus on cheap household-level fixes has reached its limits, and that the real task is building institutions capable of delivering safely managed services to everyone. Third, that treating water and sanitation insecurity as something that happens only in low-income countries is a mistake, because the same failures of affordability, access and dignity exist in high-income countries, including this one.

• 2.4 billion people live where sanitation planning embeds tools developed here
• Investment influenced in over 100 cities, benefiting over a million people directly
• 8,000 professional and government staff trained in using them
• Helped embed sanitation in the UN Sustainable Development Goals in 2015
• Leeds leads the EPSRC Water-WISER Centre for Doctoral Training
• Active research in Uganda, Tanzania, Bangladesh, Rwanda and Colombia

[Figures are taken from the REF2021 impact case study and are current as of January 2021. Worth refreshing with Barbara before publication.]

Making sanitation visible

The Shit-Flow Diagram (SFD), supported by the Service Delivery Assessment (SDA), sits at the centre of this work, developed by Barbara Evans, Professor of Public Health Engineering, with the World Bank. The name is deliberately blunt and so is its effect. The SFD shows in a single image how much of a city's faecal waste is managed safely and how much is not, while the SDA exposes the economic and institutional reasons why. Together they turn an invisible and politically awkward problem into something a mayor or a ministry can see, argue about and plan around. India, Indonesia and South Africa have built SFDs into national sanitation planning, and the approach now underpins Citywide Inclusive Sanitation, a global call to action Leeds co-authored with the Bill and Melinda Gates Foundation, Emory University, Plan International, WaterAid and the World Bank.

Sanitation and the climate

Sanitation systems are a significant and badly quantified source of greenhouse gas emissions, and they are also on the front line of climate impacts. Our current work measures emissions from sanitation systems and links them to the microbiological processes that produce them, asks how the costs and carbon of different sanitation options compare, and examines how existing systems will cope as flooding and extreme weather intensify, particularly across African cities. This is one of the fastest-moving parts of our research and it connects sanitation directly to the net zero agenda.

Systems, institutions and why services fail

Sanitation succeeds or fails on human systems as much as physical ones. Paul Hutchings, Associate Professor of Water, Sanitation and Health, is a social scientist who asks why water and sanitation systems behave as they do, and what pathways lead to more resilient and equitable services.

His particular interest is systems in transition: the point at which provision shifts from household self-supply and locally managed arrangements towards integrated, regulated services capable of delivering something better. That transition is rarely tidy. In most fast-growing cities, households, informal providers and utilities all operate at once, in a hybrid service ecosystem that no single plan governs. His research examines how governance, finance and organisational arrangements shape those transitions, how systems absorb climate shocks, and what water and sanitation insecurity actually does to the people living with it. Increasingly he applies the same lens to the UK water sector as it confronts ageing infrastructure, environmental pressure and changing public expectations.

He leads two programmes as principal investigator: WASH Systems for Health, a five-year FCDO programme running to 2028, and RESHAPE, on the resilience of health systems after extreme weather events. Through an FCDO research and learning programme he directs, our work supports NGOs strengthening water and sanitation systems across six countries in South Asia and Africa. He is Programme Leader for our Water, Sanitation and Health Engineering MSc, sits on the Water-WISER CDT management board, and is an Associate Director of water@leeds.

Ruth Sylvester, Research Fellow in Water and Health Governance, works on water and health governance in both global and UK settings, including the resilience of health systems to extreme weather and the lived experience of water insecurity at home.

Water insecurity at home

Water poverty is not only a global-south story. Around a fifth of households in England and Wales were affected by water poverty in 2020, and a much larger share now report difficulty paying their bills. Our research on lived experience, affordability and the political processes that produce these inequities brings the same analytical lens to the UK that we apply internationally, and it reflects a wider argument that the global WASH sector's exclusive focus on low- and middle-income countries has left real deprivation in wealthy countries unexamined.

Treatment, reuse and the circular economy

Safe sanitation does not end at the toilet. It depends on containment, emptying, transport, treatment and safe reuse or disposal. Miller Camargo-Valero, Associate Professor of BioResource Systems, leads research on faecal sludge and wastewater treatment and on recovering energy and nutrients from what those systems collect, linking this theme directly to our work on bioresources and the circular economy. Getting the whole chain right is what separates a sanitation system that works on paper from one that works in practice.

This is research defined by its reach beyond the university. Professor Barbara Evans serves as a Commissioner on the Lancet Commission on Water, Sanitation and Hygiene, and Health, which is reassessing WASH as a pillar of public health and a route to gender equality and social justice. She also sits on the Strategic Advisory Group of the WHO/UNICEF Joint Monitoring Programme, the body that reports global progress against SDG 6, and on the Royal Academy of Engineering's International Committee.

Our researchers lead and contribute to major international programmes, including WASH Systems for Health, a five-year FCDO programme led from Leeds by Paul Hutchings and launched at the UN Water Conference. The work is built on long partnerships with the World Bank and the Bill and Melinda Gates Foundation, and sits within water@leeds, one of the largest interdisciplinary water research centres in any university in the world, and the Centre for Global Development.

We train sanitation and WASH researchers and practitioners through our postgraduate programmes, including the cross-faculty MSc in Water, Sanitation and Health Engineering, led by Paul Hutchings and taught jointly with the Nuffield Centre for International Health and Development, and through PhD supervision across the theme. Leeds leads the EPSRC Water-WISER Centre for Doctoral Training in partnership with Loughborough and Cranfield, which has trained a cohort of doctoral researchers in water and waste infrastructure for the global south.

We welcome enquiries from prospective PhD researchers with backgrounds in engineering, environmental science, social science and public health.

[Water-WISER's own site states that no funded studentships have been available since January 2024 and that new funding is being sought. This section deliberately does not advertise open funded places. Confirm current status before publication.]

PhD opportunities · Meet the team

If you are a government, funder, utility or NGO working on sanitation, or a researcher who wants to collaborate, we would like to hear from you.

Contact the group