A survey of the characteristics and maintenance of rainwater tanks in urban areas of South Australia.

Households resident in metropolitan Adelaide and surrounding areas in South Australia were recruited into a randomised controlled trial. A total of 630 rainwater tanks with a total tank capacity of 14.5 ML were installed at the 325 households surveyed. The majority of the tanks were plumbed into the kitchen (64.6%), over 10 years in age (45.5%), over 15,000 L in capacity (42.5%) and composed of galvanised steel (36.9%). Over 90% of the households undertook one or more prevention and maintenance strategies for reducing contamination of collected rainwater. The use of first flush diverters was reported by 30.8% households, the presence of leaf control devices on the tank by 57.2%, and the presence of leaf control screens on gutters by 25.5% households. Most households reported that the rainwater tank was cleaned at some time, with 50.4% of these households stating that tank cleaning occurred 1 to 5 years previously, and 31.9% more than 5 years prior to enrolment Rainwater from the main drinking tank was sampled from a subset of households for turbidity and metals (Al, Ca, Cu, Fe, Mg, Pb, Zn). This information regarding tank characteristics and degree of adherence to recommended maintenance procedures may assist understanding of variability in rainwater quality data and may help determine whether untreated rainwater can be considered a safe water supply for household purposes including drinking.