Building capacity for rainwater harvesting in Ontario: rainwater quality and performance of RWH systems
To promote the practice of rainwater harvesting (RWH) in Ontario, two issues surrounding urban rainwater use were examined: the performance aspects of RWH systems, and rainwater quality. This study found RWH to be a practical solution for augmenting municipal water supplies; decreasing the annual mains water use of a five person water-conserving household by 30% (65 m 3) when used for toilet flushing, laundry and outdoor use. Monitoring of RWH systems during periods of cold weather indicates that these systems can operate during winter conditions, provided that the rainwater cistern is buried below the frost penetration depth, or placed in a temperature controlled environment. A significant variation in rainwater quality was observed between sites, over time, and with treatment. The absence of heavy metals, PAHs, ' Legionella,' or 'Campylobacter' in any of the rainwater samples indicates that given post-cistern treatment, rainwater end-uses could be expanded beyond those permitted by the Ontario Building Code.