Reusing Haemodialysis Reverse Osmosis Reject Water: A Case Report From a Sydney Metropolitan Hospital, Australia

Dialysis services are among health care’s most resource-intensive modalities, consuming large volumes of water and generating substantial greenhouse gas emissions. Water stewardship in health care is often overlooked despite growing global water scarcity. This case report details the design and implementation of a reverse osmosis reject water repurposing system for a 17-station, in-centre haemodialysis service in a metropolitan hospital in Sydney, Australia. With 100% capture efficiency, the system has reused over 1.33 mL of water, reducing emissions by 294.43 kg carbon dioxide equivalents (CO ₂ e) and saving AUD$3449, annually. This project is an example of a system-level success in lowering the environmental impacts of a vital health service, without compromising the quality of clinical care.