The University of Sydney's Professor Stuart Khan is a co-author of the explainer, titled Closing the Water Gap - Water, Sanitation and Hygiene for Aboriginal and Torres Strait Islander Communities. The School of Civil Engineering head said there is evidence remote communities deal with mineral and chemical contaminations from sodium, uranium, fluoride, arsenic and nitrate that exceed safe thresholds set by the Australian Drinking Water Guidelines. Prof Khan said there is no silver bullet solution to ensure safe water in remote communities, but understanding the extent of the issues was the first step.