Harvested rainwater quality: The importance of appropriate design

Ward, S.; Memon, F. A.; Butler, D.

Abstract

This paper summarises the physicochemical and microbiological quality of water from a rainwater harvesting (RWH) system in a UK-based office building. 7 microbiological and 34 physicochemical parameters were analysed during an 8 month period. Physicochemically, harvested rainwater quality posed little health risk; most parameters showed concentrations below widely used guideline levels for drinking water. However, RWH system components (e.g. fittings and down pipes) appear to be affected soft water corrosion, resulting in high concentrations of some metals (copper, zinc and aluminium). This suggests the material selection of such fittings should be considered keeping in view the hardness of rainwater of an area. Microbiologically, Cryptosporidium, Salmonella and Legionella were not present in the samples analysed. However, faecal coliform counts were high at the beginning of the study, but did decrease over time in weak correlation with increasing pH. Enterococcus faecalis displayed counts consistently above UK rainwater harvesting standards. Inappropriate roof and rainwater good design, as well as material selection appear to be responsible for the reduced microbial quality, as they promoted contributions from avian sources and inhibited cleaning activities. Building and RWH system designs require greater consideration of local factors, which are critical for optimising harvested rainwater quality, to prevent both the development of contaminated sediments and health impacts. © IWA Publishing 2010.

Citation

Ward, S., Memon, F. A., & Butler, D. (2010). Harvested rainwater quality: The importance of appropriate design. Water Science and Technology, 61(7), 1707-1714. https://doi.org/10.2166/wst.2010.102

• Journal Article Type: Article
• Acceptance Date: Jun 8, 2019
• Publication Date: Jul 20, 2010
• Deposit Date: Nov 6, 2018
• Publicly Available Date: Nov 6, 2018
• Journal: Water Science and Technology
• Print ISSN: 0273-1223
• Publisher: IWA Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 61
• Issue: 7
• Pages: 1707-1714
• DOI: https://doi.org/10.2166/wst.2010.102
• Keywords: harvested rainwater, water demand management, water quality
• Public URL: https://uwe-repository.worktribe.com/output/979948
• Publisher URL: http://doi.org/10.2166/wst.2010.102
• Additional Information: Additional Information : ©IWA Publishing (2010). The definitive peer-reviewed and edited version of this article is published in Water Science & Technology, 61, 7, 1707-1714, 2010, 10.2166/wst.2010.102 and is available at www.iwapublishing.com.