Quality Issues in Rainwater Harvesting-A Review on Current State of Knowledge and Practice

Knowledge about quality of rainwater is crutial for safeguarding human health. This review investigated harvested rainwater quality and hazardous health risk associated with it. Rain water results to physicochemical contamination and microbial contamination as it passes through atmosphere, also due to weathering and washing of roof materials, storage, faecal contamination and conveyance utilities. Rainwater is relatively free from impurities but it picks up impurities from atmosphere, also the rainwater quality deteriorates during harvesting and collection. Wind-blown dirt, faecal droppings from animals and birds, leaves, insects, contaminated litter on the catchment area are the sources of contamination of rainwater, leading some of the health risks. Coliform and E. coli were detected when the harvested rainwater was not treated with ultraviolet (UV) light. Results have shown apparent variation in the quality of rainwater by using different collection alternatives. The study shows that without proper treatment harvested rainwater may not be suitable for direct drinking, but could be used for other domestic purposes, but for direct drinking purpose it should be treated or disinfected .There are very many treatment methods, in which this review considers Solar Disinfection for investigation of its suitability in treated rainwater for portable water standards.