ALTERNATIVE WATER SOURCES FOR NON POTABLE USES IN HDB

Abstract

Water is a salient aspect for human’s survival. In Singapore where natural water resources are absent, it is crucial for the country to be water independent and to practice water conservation fervently. Within domestic water consumption, Singapore’s Public Utilities Board supplies water of a uniformed quality- drinking water standard to public housing (HDB). This promotes water management inefficiency as non potable water uses does not demand such a high water quality, hence requiring lesser treatment before distribution. This paper explores the possibility of retrofitting HDB with a dual water system obtaining water for non potable uses from alternative water sources that are clean enough for use with little treatment administered and are easily obtained in Singapore. These sources: rainwater, condensate and seawater, are assessed both quantitatively and qualitatively, based on calculations of non potable water consumption of a single HDB block and international water quality standards. It was found that while rainwater and condensate provided high water quality, rainwater was able to better fulfil non potable water consumption. Seawater being more suitable for toilet flushing specifically was also estimated to fulfill specifically toilet flushing requirements but required greater maintenance due to its water quality which encouraged pipe corrosion.