A Review of Water Reuse and Recycling, with Reference to Canadian Practice and Potential: 1. Incentives and Implementation

As a country on the whole, Canada enjoys abundant freshwater resources, yet there remain regions with severe discrepancies between supply and demand. One solution to insufficient water supplies that has been gaining in popularity in other areas of the world is that of water reuse. Reuse or recycling of treated wastewater reduces effluent discharges into receiving waters and offers a reliable alternative supply of water for applications that do not require high-quality water, freeing up limited potable water resources. As compared to other countries worldwide, water reuse is currently practised infrequently in Canada. Use of reclaimed water requires a clear definition of the quality of water required, and while water quality criteria typically focus on pathogen risk to human health, chemical contaminants may also limit suitability for some reuse applications. Both health and environmental risk assessments are important steps in designing criteria for reuse projects. Alberta and British Columbia have recently produced guidance documents for water reuse projects; the permitted applications are discussed and the water quality criteria are compared with other standards and guidelines. Various treatment technologies for on-site and central wastewater reclamation facilities are described. Additional considerations for implementation of water reuse projects include project feasibility and planning, infrastructure needs, economics, and public acceptance.