WATER REUSE IN CANADA: OPPORTUNITIES AND CHALLENGES

摘要

Reclamation and reuse of various types of wastewater, including stormwater, greywater, and domestic wastewater, represents an important component of the urban water cycle helping close the loop between water supply and wastewater disposal. Safe and scientifically-based water and wastewater reuse has been practised for about a century, and a great wealth of practical experience with such practices has been reported in the literature. Essential elements of water reuse plans include the selection of categories of reuse, selection of water quality criteria for such specific reuses (in accordance with the existing regulations and guidelines), design of the treatment train providing the effluent of the required quality, and examination of overall feasibility. In Canada, water reuse is generally conducted on a small-scale or experimental basis. While no national guidelines exist at this time, a number of provinces have developed guidelines for specific water reuse applications. The current stresses on water supply, caused by growing population and increasing water demands, depletion of water sources, reduced supply reliability caused by climate change, ageing infrastructure and limited funding for its expansion, as well as the promotion of environmental sustainability and needs to reduce wastewater discharges to sensitive receiving waters, will contribute to further growth and expansion of water and wastewater reclamation and reuse.