The world-heritage listed Wollangambe River, which runs through spectacular canyons in the Blue Mountains, is under threat from pollution flowing into its upper reaches from a Lithgow coal mine.

The river is being pumped with waste water discharged from the Clarence Collier coal mine, which is harming the ecology of the waterway.

The Wollangambe River in the Blue Mountians. Credit:Mark Finney

Scientists from the University of Western Sydney School of Science and Health, claim licence restrictions placed by the Environmental Protection Authority (EPA) on mine pollution are not enough. They want an investigation to identify all the contaminants that are flowing from the mine.

"The river is beautiful - it really is a scenically amazing place, but the sad reality is that the mine is silently poisoning the place and we have no idea how this is affecting the wildlife," said Dr Ian Wright from UWS.