Alleviating health risks associated with rainwater harvesting

Perceived and real public health risks associated with the quality of water from alternative water sources and supply systems, such as rainwater harvesting (RWH) and grey water reuse, continue to restrict their uptake in many countries. One option to alleviate these health risks is to treat alternative water to potable standard at the point of use (POU) as opposed to the point of supply, as undertaken in centralised systems. This paper presents the results of three international empirical field trials of a novel POU RWH treatment device. The results indicate that where the harvested rainwater did not contain elevated levels of pesticides or physico-chemical determinands, the POU device was able to reduce levels in outlet water to meet UK, EU and World Health Organization potable standards. Regarding microbiological determinands, such as total viable counts and coliforms, and microbial pathogens, such as Pseudomonas aeruginosa and Legionella spp., the device achieved reduction to potable standard and full pathogen removal, respectively. Thus, while it is possible to treat harvested rainwater to potable standard with a POU device, whether it is desirable to do so to alleviate risks for all end uses remains a question for further debate

Impact of UV–H 2

Cyanobacteria and their taste and odor (T&O) compounds are a growing concern in water sources globally. Geosmin and 2-methylisoborneol (MIB) are the most commonly detected T&O compounds associated with cyanobacterial presence in drinking water sources. The use of ultraviolet and hydrogen peroxide (H 2 O 2 ) as an advanced oxidation treatment for T&O control is an emerging technology. However, residual H 2 O 2 (>80% of the initial dose) has to be removed from water prior final disinfection. Recently, granular activated carbon (GAC) is used to remove H 2 O 2 residual. The objective of this study is to assess the impact of H 2 O 2 quenching and aging processes on GAC capacity for the removal of geosmin and MIB. Pilot columns with different types of GAC and presence/absence of H 2 O 2 have been used for this study. H 2 O 2 removal for the operational period of 6 months has no significant impact on GAC capacity to remove the geosmin and MIB from water

Consumption of nonpublic water: implications for children's caries experience

The definitive version is available at www.blackwell-synergy.com Copyright © 2006 International Association for the Study of Pain Published by Elsevier B.V. Copyright © 2006 Blackwell MunksgaardAbstract – There are concerns that the consumption of unfluoridated bottled and tank water may put children at increased risk of developing caries. Objectives: The aim of this study was to investigate the relationship between nonpublic water consumption (either from bottles or rainwater tanks) and socioeconomic status (SES) and both deciduous and permanent caries experience. Methods: A random sample of children enrolled in the School Dental Service of South Australia participated in the study (response rate = 71.8%, n = 9988). Results: Forty-five per cent of children had greater than 50% lifetime consumption of nonpublic water while 36% of children had 0% lifetime consumption. Increased use of nonpublic water occurred for children from lower socioeconomic groups, two-parent families and children from nonmetropolitan areas, with these results most likely a result of the residential location of the children. Multivariate modelling revealed a significant positive relationship between deciduous caries experience and consumption of nonpublic water, even after controlling for the age and sex of the child, SES and residential location. This relationship was significant only for those children with 100% lifetime availability of fluoridated water. The effect of consumption of nonpublic water on permanent caries experience was not significant. It is postulated that these findings may result from the lower caries activity in the permanent dentition of children aged 10–15 and possible dietary confounders. Conclusion: Recommendations are made for the addition of fluoride to bottled water, especially with regard to the oral health of younger children.Jason M. Armfield and A. John Spence