It's at the end of a suburban street, in a spot between a muddy cul-de-sac and the banks of the Werribee River, that bubbles spew out of a hard-to-see drain.
They go unnoticed by a Bacchus Marsh resident as he walks past kicking a ball, but for inspectors from Victoria's Environment Protection Authority, they're a cause for concern.
"What we have observed is some water bubbling out … what looks like a detergent material," explains chief executive Lee Miezis, who has travelled the 60 kilometres north-west of Melbourne to be here with his team.
