The NSW Environmental Protection Authority has a warning for all owners of vacant lots - install fencing before an illegal dumper strikes.
The warning comes after Austral property owner Michael Porteous was left with a sizeable clean-up bill to remove 12 tonnes of asbestos waste which was dumped onto his vacant lot just before Christmas.
The EPA said illegal dumpers targetted unfenced lands in new subdivisions, where lack of neighbours - witnesses - meant dumping could be carried out largely unnoticed.
With no one around to witness the crime, it is very difficult for the EPA to find and punish the culprits.
Mr Porteous said he was shocked to find the waste dumped on his property.
"It never occurred to me that dumping was a possibility," he said.
"It was just random - someone came in and back their truck onto the block and dumped out all this asbestos.
"Maybe they were working on another site and didn't want to pay the disposal costs, so they just dumped it.
"We asked everyone but the houses are empty and being built, so no one saw anything."
Mr Porteous had to pay $8000 to clean up the hazardous waste illegally dumped on his property.
Following the asbestos removal, he built a fence around his property.
"If you are going to buy a block of land then I recommend you immediately put up some sort of fencing, so no one can drive a truck on to it," Mr Porteous said.
"In new areas where no one is living nearby, they know there is a small chance of someone seeing them.
"It is much less expensive to put up a fence than to have to clean up asbestos."
If dumpers are identified, the EPA can issue fines and penalties ranging from $7500 for individuals to $15,000 for corporations.
Vehicles which have been used for repeated dumping offences can be seized, while repeat offenders can face up to two years in prison.
Court-imposed maximum penalties for illegal dumping are $250,000 for an individual and up to $1 million for corporations.
EPA director of major compliance and investigations Greg Sheehy said dodgy operators favoured isolated blocks in new land releases. Such sites are plentiful in the Macarthur region, which is growing faster than almost anywhere else in the state.
"Illegal dumping is a serious environmental crime and if the dumper can't be identified, the landowner is stuck with the clean-up, which can be very expensive," Mr Sheehy said.
"The community can help the EPA crack down on illegal dumpers by reporting any suspicious activity to our 24/7 Environment Line on 131 500.
"We will actively pursue offenders and will not hesitate to prosecute."
The EPA has been working with the construction industry to ensure waste is disposed of properly. The NSW Government has also released the NSW Asbestos Waste Strategy 2019-21 which aims to reduce illegal asbestos dumping by making it easier and cheaper to dispose of.