Climate change is now considered to be a major global public health concern. However, the very provision of health care itself has a significant impact upon the environment. Action must be taken to reduce this impact. Water is a precious and finite natural resource. Vast quantities of high-grade water are required to provide haemodialysis. The reverse osmosis systems used in the purification process reject approximately two-thirds of the water presented to them. Therefore, around 250 litres of 'reject water' result from the production of the dialysate required for one treatment. This good quality reject water is lost-to-drain in the vast majority of centres worldwide. Simple methodologies exist to recycle this water for alternative purposes. We describe here a case study of the only UK renal service we know to have implemented such water-saving methodologies. We outline the benefits in terms of financial and environmental savings.