WATER HYGIENE AND SAFETY
Reducing the risks from hospital wastewater
IHEEM-registered Authorising Engineer (Water), Karina Jones, of Eta Projects, discusses some of the risks to patients in hospitals and other healthcare facilities from contaminated wastewater, and suggests a number of often simple-to-implement measures that can be taken to mitigate these risks.
Hospital wastewater (HWW) is characterised by the presence of various emerging contaminants, such as pharmaceutically active compounds (PhACs), several microorganisms, including antibiotic-resistant bacteria (ARB), Carbapenemase-producing Enterobacterales (CPE), antibiotic-resistant genes (ARG), and persistent viruses, etc. It is important to note that Carbapenem antibiotics are often considered a last-resort treatment, as they represent the final suite of antibiotics available. However, increasing bacterial resistance to them underscores the urgent need for antibiotic stewardship. Healthcare is a rapidly growing industry, as medical treatments become more sophisticated and more in demand due to the increasing incidence of chronic disease. I will be exploring the following. n Water Safety Groups: are we aware of wastewater risk to patients, and how are we controlling the processes?
n Water Safety Plan documents, including wastewater vigilance.
n How can we reduce the risk of contaminants from wastewater to patients?
n Hospital clinical waste and wastewater, and how to manage contaminates safely.
n What preventative strategies are available to mitigate the risk from wastewater?
Wastewater and sewers – The superhighway for the movement of organisms across a healthcare setting I would like to begin with the acknowledgement to Professor Joachim Kohn,1
who has explored his interest
in pathology, and was the ‘inventor extraordinary to the Medical Laboratory’; he died in London on 31 March 1987. Born in Poland in 1912, he qualified in medicine there in 1936, served in the Polish forces, and became a prisoner of war in Russia until 1941, being one of the few officers to survive the Katyn massacre. He continued to support the war efforts, and when he moved to the UK, he served bravely in the British 8th Army throughout its campaigns until 1947. In peacetime he became a ship’s surgeon for two years before training at St Mary’s Hospital Roehampton, where he became a Consultant Clinical Pathologist in 1955, and later a Senior Lecturer in Chemical Pathology at the University of London, officially retiring in 1977. You may ask yourself why I have mentioned this
highly driven and altruistic man, and what connection could he possibly have with wastewater and drainage contamination. Professor Joachim Kohn invented a device known as the ‘Kohn trap’ to thermally disinfect sink traps
August 2025 Health Estate Journal 49 in 1970.2 This was to aid the disinfection of the domestic
wastewater system at the point of discharge (washhand basin drain). At the time of his invention it was not recognised that microbial contamination could possibly be passed on to patients from wastewater contaminates. Unfortunately, many years later, the tragic neonatal outbreak of Pseudomonas aeruginosa in Belfast in 2012 forced change in the way we think about contamination of domestic water systems and water outlets such as complex taps, including possible cross-contamination from splashback from drains and the wastewater systems. Tragically, four babies died from an outbreak of Pseudomonas aeruginosa in Northern Ireland – one died at a Londonderry hospital, and three others in Belfast. Due to this event the Department of Health issued the first HTM 04-01 Addendum: Pseudomonas aeruginosa – advice for augmented care units, in 2013. The guidance recommended significant change in the way we adopt water management across healthcare in high-risk areas such as augmented care wards. The requirement to conduct Pseudomonas aeruginosa testing of the domestic water in healthcare was initiated, and this continues today.
Remedial action and regular re-sampling The Pseudomonas aeruginosa sampling regime identifies contaminated outlets which must be addressed through remedial action, with a continuing need for a strict re-sampling schedule to ensure that outlets are
Hospital sites often have limited available space, so tank farm design and layout aim to optimise this space while ensuring safe and manageable access.
All photos used courtesy of Pharmafilter
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