Managing the Risk from Drains and Wastewater in Healthcare Premises
13:00 - 14:00, Wednesday 3rd September 2025
The building drainage system is often overlooked as a key factor in the transmission of pathogens throughout a healthcare building. The fluid mechanics, particularly the movement of air through the system, lends itself to a number of different risk factors which are difficult to predict and measure. While it is known that wastewater can be considered hazardous and toxic, contributing to the spread of anti-microbial resistance, work on hospital specific building drainage systems has been scant and evidence has been hard to come by. This presentation will explore the role of the building drainage system on the spread of pathogens and the potential risk to patients. The main phenomena involved in this transmission route are - aerosolization, turbulence and the generation of air pressure transients which can cause pathogens to emerge from contaminated water trap seals back into the room from a range of appliances.
Chair: Dr Susanne Surman-Lee, Leegionella Ltd.
Dr Surman-Lee is a Consultant Clinical Scientist Registered with the UK Health Professions Council with over 40 years experience in clinical and public health microbiology and practical experience of auditing and investigating over 60 healthcare and non-healthcare premises following incidents, cases and/or outbreaks of water systems and associated equipment nationally and internationally, including from Legionella, Pseudomonas aeruginosa, NTM. She has also worked as a temporary advisor on water hygiene in healthcare for WHO in the Middle East and was a Member of the WHO working and editorial groups which published Legionella and the prevention of legionellosis (2007) and Water Safety in Buildings (2011). Susanne has also for over 20 years had input into national and international standards and guidance on water hygiene including for the Health and Safety Executive and Department of Health as well as chairing committees developing key British Standards Institute Water Hygiene Standards which are supporting the UK to achieve the UN Sustainable Development Goal (SDG 6), Clean water and sanitation. Susanne was also the lead technical author of the new NHS Estates NETB 2024/3 Designing safe spaces for patients at high risk of infection from nontuberculous mycobacteria and other waterborne pathogens.
Speaker: Professor Michael Gormley, Heriot-Watt University
Professor Michael Gormley, Professor of Public Health and Environmental Engineering at Heriot-Watt University, Edinburgh in Scotland. He is a chartered engineer with 40 years' experience in both practise and academia. Since Joining Heriot-Watt University in 2000 he has worked on areas of engineering design and modelling of water and sanitation systems globally. With an extensive track record of attracting research grants from Government research organisations and industry in the areas of sustainability and improving public health for all people. Gormley's work is close to policy and he has been an advisor to the UK Government on the transmission and mitigation of COVID-19 through participation in the Scientific Advisory Group for Emergencies (SAGE), during the COVID-19 pandemic. In addition to research in Fluid Mechanics and sanitation provision he is also an expert on the transmission and fate of aerosolised pathogens found in airflows, particularly in Building Sanitary Plumbing Systems. His most recent work has focussed on the transmission of pathogens from contaminated water trap seals in wash-hand basins in healthcare buildings and the linkages between that transmission pathway, wastewater fluid dynamics and the spread of AMR organisms. He is a named inventor on four international patents in the field of public health engineering.