Lead, zinc and silver have been mined at Broken Hill since the 1880s. The dry climate leads to dust clouds, which contain traces of heavy metals. That dust settles on roofs and washes into rainwater tanks. Australian drinking water guidelines state that anything above 0.01 mg of lead a litre is hazardous to human health. Dr Ian Wright, an associate professor in environmental science at Western Sydney University, said there is no “safe” level of lead in drinking water. Health departments generally do advise that if you have a reticulated [mains] water supply available, you use that for drinking and you use rainwater tanks for outdoor uses, possibly flushing toilets and things like that,” Khan said. Coombes said while animal faeces may end up in a rainwater tank, this rarely posed a serious health risk.

But reports of heavy metal contamination near Orange last month have triggered some farmers in the NSW central west to rethink their water quality. Community-led testing of the private rainwater supplies for 40 houses within a 10km radius of the Newcrest Cadia goldmine, sparked by visible dust clouds from the mine, found one in three samples showed unsafe lead levels. The source of the lead and other heavy metal contaminants has not been confirmed. Rainwater tanks are a standard feature on most Australian farmhouses, which are often not connected to mains water. The majority of rainwater is fit for purpose and good quality. There’s a small amount of problems from time to time, as there is with mains water.”Every health survey that’s ever been done shows rainwater is as good or better than mains water,” said Dr Peter Coombes, professor at the Australian National University.

verifyErrors }}{{ message }}{{ /verifyErrors }}{{ Stuart Khan, professor in the school of civil and environmental engineering at the University of NSW, said people should not assume all rainwater is safe to drink. Access to safe and clean drinking water is a human right and, in Australia, it’s widely assumed all water from a tap is OK. But as water quality warnings in some regional New South Wales towns have shown, both rain and groundwater can become polluted and some scientists say it’s time to have a rethink. But there are many places in Australia that rely on rainwater to drink, places that are not on reticulated water supplies.” If you’ve got bat poo or bird poo on your roof … then there is a real risk of bacterial contamination Stuart KhanWith heywell, function meets flavor. Our sparkling waters are a balance of tart and sweet, low in sugar and calories, and made with premium plant-based organic ingredients. Non-GMO, gluten free, dairy free and vegan. Other researchers who spoke to Guardian Australia said while there were some risks associated with rainwater, it often scored better than mains water. Australian drinking water guidelines state anything above 0.01 mg of lead a litre is hazardous to human health. Photograph: Jason Edwards/Getty Images Groundwater drawn from more shallow aquifers is often contaminated with surface pollutants, Khan said. It’s not just mining that can cause a problem for rainwater. Water Research Australia, an organisation comprised of academics, scientists and representatives from state and federal water agencies, has also investigated the health impacts of bacteria and other pathogens in rainwater.