Tim O'Halloran always thought rainwater from his tank was clean, that was until he put his water supply to the test during a monitoring project.
A project in south-west NSW found bacteria in 60 per cent of 17 rainwater tanks tested
Guidelines say birds, small animals, and roof debris are the main sources of contamination
There are fears climate change will effect the quality of tank water as organisms thrive in warmer water
"You put your rainwater into a little cup, leave it there for an hour or two, then you watch the water turn a horrible, horrible colour and you know it's full of some sort of germs," he said.
"I know river water is a bit ordinary but I always thought rainwater was pretty pure."
The project, conducted at Balranald in the western Riverina, saw 17 water screening tests carried out on rainwater tanks.
Sixty per cent of those returned a positive recording for types of bacteria that could indicate the presence of viral organisms that can make people sick.
If you are looking to get your rain water tank tested, please contact the team at ALTSA today.