There is a growing problem with people dumping toxic waste and other rubbish in New South Wales north coast public forests.
State Forests, the National Parks Service and local councils believe the main culprits are people trying to avoid paying tip fees.
David Wilson from Forest New South Wales says a significant issue is with people dumping old fibro which contains hazardous asbestos particles.
He says it is hard to believe the type of rubbish that ends up in public forests.
"A lot comes from just local residents, just kitchen and general household rubbish," he said.
"Then we have people who are leaving the district, want to dump a couple of trailer-loads of old furniture.
"Others who bring hazardous waste, unknown liquids dumped in drums.
"It can be anything from chip oil from fish and chip shops - there can be agricultural chemicals out of date being dumped."
Mr Wilson says dumped garden waste can release invasive weeds into national parks and state forests.
However, he says it is the dangerous waste that is the most significant issue.
"Pressurised cans, we can be out doing hazard reduction burning or controlling fires and we have explosions out in the fires, so it becomes dangerous for our staff," he said.
"But some of them we've found in 200 litre drums leaking into the environment.
"We advise the EPA [Environment Protection Authority] when we find materials like that.
"There are very heavy fines and jail sentences when it comes to hazardous waste dumping."