PUBLICATIONS & RESEARCH
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Abbott, S., Caughley, B. 2012. “Roof-Collected Rainwater Consumption and Health.” Paper presented at the 5th Pacific Water Conference. Nov 1, 2012. Auckland, NZ. Available online: http://www.pwwa.ws/pdfs/Stan_Abbott_RWH_Consumption_Health_Handout.pdf.
Page 10.
Because of the many benefits roof water harvesting should unquestionably be encouraged for both urban and rural environments since rainwater tanks are a visible and high profile method of conserving water and can be used to reinforce and promote water conservation policies and practices. However, there must be an awareness among the general public, local authorities, and regional public health services about the health risks associated with contaminated roof water. Providing the roof-collected rainwater is clear, has little taste or smell and is collected from a well-maintained system, it is probably safe and unlikely to cause any illness in most users. The health risks of roof- collected rainwater can be minimised by sensible preventative management procedures. Some of the preventative measures are associated with design and installation while others are associated with ongoing maintenance. Well-designed systems are low maintenance and will generally prevent problems occurring so that corrective action to restore safe rainwater quality will be needed infrequently.
American Water Works Association (AWWA). 2012. “Buried No Longer: Confronting America’s Water Infrastructure Challenge.” Available online: https://www.awwa.org/Portals/0/files/legreg/documents/BuriedNoLonger.pdf
As documented in this report, restoring existing water systems as they reach the end of their useful lives and expanding them to serve a growing population will cost at least $1 trillion over the next 25 years, if we are to maintain current levels of water service.
Coombes, P.J., Barry, M., Smit, M. 2018. “Systems Analysis and Big Data Reveals Benefits of New Economy Solutions at Multiple Scales.” Paper presented at WSUD 2018 and Hydropolis 2018. Feb 12–15, 2018. Perth, Western Australia.
Coombes, P.J. 2016. “Response to Reply by AR Ladson and MI Magyar,” in Vol 19, No.1, pp. 88–90, Australian Journal of Water Resources, DOI. Available online: http://dx.doi.org/10.1080/13241583.2015.1131597
Page 2, on using e.Coli as an indicator of water quality:
Use of e. coli as an indicator of possible faecal contamination of environmental waters is likely to result in overestimation of perceived risk.
Page 2:
Our research has revealed a rainwater treatment train (for example: Coombes 2002; Spinks 2007; Morrow 2012) and has confirmed that the quality of rainwater varies at divergent points in the rainwater harvesting systems from roof to storage to tap (for example: Morrow 2012, Morrow et al. 2010; Evans 2010; Martin et al. 2010; Spinks 2007, Coombes 2002). The assessment of water quality from rainwater harvesting systems is critically dependent on the sample location within the treatment train, position in the rainwater storage and on repeated sampling protocols. It was a key finnding by Morrow (2012) and Coombes (2002) that that the general nature of rainwater sampling investigations obscures actual water quality outcomes.
Coombes, P.J. 2015. Discussion on “Influence of Roofing Materials and Lead Flashing on Rainwater Tank Contamination by Metals,” by M.I. Magyar, A.R. Ladson, C. Daipe, and V.G. Mitchell. Australian Journal of Water Resources 19(1).
Page 2, on using e.Coli as an indicator of water quality:
Use of e. coli as an indicator of possible faecal contamination of environmental waters is likely to result in overestimation of perceived risk.
Page 2:
Our research has revealed a rainwater treatment train (for example: Coombes 2002; Spinks 2007; Morrow 2012) and has confirmed that the quality of rainwater varies at divergent points in the rainwater harvesting systems from roof to storage to tap (for example: Morrow 2012, Morrow et al. 2010; Evans 2010; Martin et al. 2010; Spinks 2007, Coombes 2002). The assessment of water quality from rainwater harvesting systems is critically dependent on the sample location within the treatment train, position in the rainwater storage and on repeated sampling protocols. It was a key finnding by Morrow (2012) and Coombes (2002) that that the general nature of rainwater sampling investigations obscures actual water quality outcomes.
Coombes, P.J., Barry, M.E. 2007. “The Effect of Selection of Time Steps and Average Assumptions on the Continuous Simulation of Rainwater Harvesting Strategies,” Water Science and Technology Vol 55, No 4, pp. 125–133. IWA Publishing.
Coombes, P.J. et al. 2006. “Key Messages from a Decade of Water Quality Research into Roof Collected Rainwater Supplies.” Paper presented at Hydropolis 2006. Perth, Western Australia.
This paper provides an overview of some key observations from the research program into the quality of water supply from rainwater tanks conducted over the last decade. The research journey provides some key insights into water quality processes in rainwater tanks and highlights the need for continuing scientific endeavour to replace myths and agendas with facts about this important water source. Read more / download.
Dean, J. and Hunter, P.R. 2012. “Risk of Gastrointestinal Illness Associated with the Consumption of Rainwater: A Systematic Review.” Environmental Science and Technology 46, pp. 2501–2507. Available Online: https://pubs.acs.org/doi/abs/10.1021/es203351n
We conclude that the evidence suggests that rainwater is safer than water from unimproved water supplies. Where feasible rainwater harvesting should be encouraged as a step toward achieving millennium development targets.
enHealth. 2010. “Guidance on the Use of Rainwater Tanks,” 3rd Ed. Commonwealth of Australia. Available online: http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-enhealth-raintank-cnt.htm
Pg iii:
Collection and storage of rainwater involves relatively simple systems. A reasonably low level of management can ensure provision of good quality water that can be used for a wide range of purposes including drinking, food preparation, bathing, laundry, toilet flushing and garden watering.
Pg 9, on Legionella:
While rainwater tanks can provide environments for Legionella, they are common environmental organisms. Infection normally follows amplification in warm water and dissemination in aerosols. There is little evidence that rainwater tank supplies are associated with increased public health risk. Tanks should be kept clean and the rainwater, when used in hot water systems, stored and delivered to reduce the likelihood of the growth of Legionella bacteria, and also reduce the likelihood of burns and scalds.
Pg 9, on illness and rainwater tanks:
The relatively frequent detection of faecal indicator bacteria is not surprising, given that roof catchments and guttering are subject to contamination by bird and small animal droppings. However, despite the prevalence of indicator organisms, reports of illness associated with rainwater tanks are relatively infrequent. Although traditional under-reporting of gastrointestinal illness will contribute to a lack of evidence, epidemiological investigations undertaken in South Australia have failed to identify links between rainwater tanks and illness (Heyworth et al. 1999; Heyworth 2001; Rodrigo et al. 2010).
Pg 10, on illness and rainwater tanks:
In summary, the study conducted in South Australia found no measurable difference in rates of gastrointestinal illness in children who drank rainwater compared to those who drank mains water. However, there are examples of Campylobacter and Salmonella enteritis associated with rainwater tanks and one example of cryptosporidiosis/ giardiasis associated with an underground tank. Faults in tank design or poor maintenance were identified as contributory factors in some of the investigations of illness.
P. 26, on testing:
Microbial testing of rainwater from domestic tanks is rarely necessary and in most cases is not recommended. Water quality in rainwater tanks can change rapidly during wet weather and, during dry periods, the concentrations of indicator bacteria (E. coli) and faecal pathogen numbers decrease due to die-off (Edberg et al. 2000). Testing for speci c pathogens is often expensive and is generally only warranted as part of an outbreak investigation. If there are strong concerns about water quality, chlorination of tank water is a suitable alternative to testing. If microbial testing is undertaken, the parameter of choice is E. coli as an indicator of faecal contamination. Tests for total coliforms or heterotrophic plate counts are of little value as indicators of the safety of rainwater for drinking.
Chemical testing should only be required in exceptional circumstances, such as in specific areas where there are concerns about impacts from major industrial or agricultural emissions. In these circumstances the chemicals of concern need to be identifed before testing or large costs can be incurred with limited likelihood of successful detection.
Evans, C.A. et al. 2007. “Coliforms, Biofilms, Microbial Diversity and the Quality of Roof-Harvested Rainwater,” School of Environmental and Life Sciences University of Newcastle, Callaghan NSW, Australia.
Evans, C.A. et al. 2009. “Extensive Bacterial Diversity Indicates the Potential Operation of a Dynamic Micro-Ecology Within Domestic Rainwater Storage Systems,” Science of the Total Environment 407, pp. 5206–5215.
Jones, C. 2010. “Soil Carbon—Can It Save Agriculture’s Bacon?” Paper presented at the Agriculture and Greenhouse Emissions Conference. (http://www.amazingcarbon.com/PDF/JONES-SoilCarbonandAgriculture.pdf (Revised May18, 2010)
Harvie, J., Lent, T. (Draft 2011) “PVC-Free Pipe Purchasers’ Report,” Healthy Building Network Washington, DC. https://healthybuilding.net/uploads/files/pvc-free-pipe-purchasers-report.pdf
Lucas, S.A. et al. 2006. “Rainwater Harvesting: Revealing the Detail,” Water Journal of the Australian Water Association 33. Pp. 50–55.
Heyworth J.S. et al. 2006. “Consumption of Untreated Tank Rainwater and Gastroenteritis Among Young Children in South Australia,” International Journal of Epidemiology 35(4) pp. 1051–1058.
Mack, E.A., Wrase, S. 2017. “A Burgeoning Crisis? A Nationwide Assessment of the Geography of Water Affordability in the United States,” PLoS ONE 12(1): e0169488. https://doi.org/10.1371/journal.pone.0169488
Mechell, J. et al. 2010. “Rainwater Harvesting: System Planning.” Texas AgriLife Extension Service. College Station.
Morrow, A. 2012. “Variations in Inorganic and Organic Composition of Roof-Harvested Rainwater: Studies at the Regional and Individual Site Level in Eastern and Southern Australia.” Doctor of Philosophy thesis submitted to The University of Newcastle, Australia.
Morrow, A. et al. 2007. “Elements in Tank Water—Comparisons with Mains Water and Effects of Locality and Roofing Materials.” Rainwater and Urban Design 07—Incorporating the 13 International Rainwater Catchment Systems Conference and 5th Water Sensitive Urban Design Conference, August 21–23, Sydney Australia.
Regional District of Nanaimo, Rainwater Harvesting Best Practices Guidebook. Free download at www.rdn.bc.ca/rainwater-harvesting.
Rodrigo S. et al. 2009. “Drinking Rainwater: A Double-Blinded, Randomized Controlled Study of Water Treatment Filters and Gastroenteritis Incidence,” American Journal of Public Health 101(5) pp. 842–847.
Spinks, A. 2007. “Water Quality, Incidental Treatment, Train Mechanisms and Health Risks associated with Urban Rainwater Harvesting Systems in Australia.” Doctor of Philosophy thesis submitted to The University of Newcastle, Australia.
TCEQ. 2007. “Harvesting, Storing, and Treating Rainwater for Domestic Indoor Use.” Texas Commission on Environmental Quality (TCEQ). GI- 366. Jan 2007. Available online: http://rainwaterharvesting.tamu.edu/files/2011/05/gi-366_2021994.pdf
USDA National Engineering Handbook. 1997. “Irrigation Guide, Part 652.” Available online: https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17837.wba
