Water quality management of rooftop rainwater harvesting systems

The ancient technique of harvesting rainwater falling on rooftops, which had been forgotten after the advent of large-scale centralized water resource systems like dam-based reservoirs, has staged a global comeback in the post-modern era. It is expected that in the near future all dwellings everywhere will be equipped to harvest and use rainwater. Such widespread use of rooftop rainwater harvesting makes it very important that the water quality aspects associated with it are clearly understood and managed. The present paper addresses the related issues. The pathways by which pollutants can enter in a rainwater harvest have been traced and the strategies to manage the water quality, at pre-harvest as well as post-harvest stages, have been discussed.