Smart metering and communication interventions reduce significant water leakage by faulty toilets in purpose-built student accommodation

Abstract

Water efficiency is a global sustainability challenge encapsulated in the United Nation’s Sustainable Development Goal 6 (SDG6), target 6.4. We used building level smart metering to investigate low endpoint water use efficiency in purpose-built student accommodation blocks, a rapidly growing residence type in the United Kingdom. Baseflow accounted for up to 42% of the annual water demand in three accommodation blocks housing 240 students at Newcastle University. Audits identified faulty, continuously running toilets as the main reason for these high baseflows. Each faulty toilet wasted between 4,800 to 12,000 litres per day of potable water, equivalent to the baseflow corrected water use of between 47 and 106 students. The median payback period for recovering the cost of toilet repairs via reduced water bills was 2.9 days, less than the median 6-day period of water wastage before a faulty toilet was identified and repaired. Management, maintenance and cleaning staff, and student occupant engagements reduced baseflows in Windsor Terrace from 4,577 cubic meters in the calendar year 2017 to 2,453 cubic meters in the calendar year 2019. These water savings amounted to an annual water bill saving of £4,023, five times higher than the £828 annual smart metering costs. We conclude that rapid identification and repair of faulty appliances supported by smart metering is a cost effective and sustainable water efficiency strategy. With timely repairs of faulty appliances, significant water savings can be achieved without up-front investment into additional infrastructures such as water storage tanks and pipes, which have embedded environmental impacts.