The housing development boom in the GTA has spawned an accompanying, much more dangerous business: illegal dumping of unwanted, and sometimes toxic, soil.

The dirt dumps are popping up on farmers' fields and vacant lots across the region, according to the Lake Simcoe Region Conservation Authority — one of the organizations that's trying to curb the burgeoning trade in illegal soil.

"I've seen trucks — 10, 20 deep — parked along the road coming in and dumping every couple of minutes. If you can generate 30 loads an hour at $100, that's three grand an hour," said Rob Baldwin, planning head at the LSRCA.

It absolutely creates a black market. - Rob Baldwin, LSRCA planning head

"If that's half the cost of a legal tipping site, that's the lucrative side for those companies that are disposing of the fill. It absolutely creates a black market."

The problem arises from the fact that every time another basement in a new subdivision is excavated, the dirt has to be dumped somewhere. Rather than using the province's regulated, and costly, soil dump sites, some contractors are turning to soil brokers — middlemen who, for a fee, match builders with willing landowners.

Lake Simcoe Region Conservation Authority planning head Rob Baldwin wants increased powers to investigate properties that he suspects are being used as illegal dump sites. (Tina Mackenzie/CBC)

And those middlemen, Baldwin says, are often members of organized crime groups.

"We've heard a lot of stories about certain organized crime entities, whether it's the the local biker gangs, as well as the Mafia being involved," he said.

"It's a very cash heavy business."

The LSRCA has become involved because wetlands and shorelines, which are often tantalizingly vacant, have become favourite options for illegal dumpers, Baldwin says.

And there are serious risks to the public, he adds.

When tonnes of dirt, toxic or clean, are dumped onto a flood plain, it raises the risk that the next heavy rainfall could lead to a serious flood.

"If you have a thousand dump truck loads in the flood plain that take up all the space for the water, where is that water going to go? To the house next door?"

Linda Kapeleris says she's fed up with dump trucks travelling day and night to illegal soil dump sites near her home. (Tina Mackenzie/CBC)

As well, he says, landowners who illegally accept soil for a price — usually $75 to $100 a truckload — have no way of knowing if it contains contaminants. If it does, the landowner is on the hook for the clean-up price, which can be tens of thousands of dollars.

In an area as fertile as the Holland Marsh, which the LSRCA regulates, Baldwin says there's also a real danger that the food supply could become contaminated.

The public in some of these areas appears to be taking notice. Baldwin recently identified a property on Ravenshoe Road in Georgina Township, near Keswick, that was being used a dump site.

Neighbour Linda Kapeleris has lived on Ravenshoe Road for 27 years and she says it's obvious that the area has become a hotbed for illegal dumping:

"They've even started dumping at night," she told CBC Toronto.

"A dozen dump trucks racing along there at midnight, 1 a.m. I've gotten up at 3 a.m. to see if they're ever going to stop."

It is legal for developers to dump waste soil from new subdivisions on private land, provided the owner of the property has received a permit from either the local conservation authority or the municipality, according to Ian McLaurin, an engineer who heads a watchdog group called the Ontario Soil Regulation Task Force. Those permits are rarely granted, however.

Excess soil lies in a pile near the site of a new subdivision in Queensville, just north of Toronto. (Mike Smee/CBC)

And there is a lot of waste soil being generated.

"We do know that there's about 25 million cubic metres of soil looking for a place to go every single year in Ontario," he says.

"You can imagine the Rogers Centre? Sixteen of those filled with dirt every year. Some of it's contaminated, some of it's not."

Legal dumps too pricey

But at a cost of $150 or more per truckload, legitimate sites can be expensive for developers, compared to the prices charged by unregulated dump site, even when the broker's fee is tacked on.

In the case he's investigating on Ravenshoe Road, Baldwin says the landowner had obtained a permit from the LSRCA that allowed him to accept eight inches of soil.

Baldwin says the landowner took significantly more than was allowed but declined to say how much more.

Ian McLaurin, of the Ontario Soil Regulation Task Force, says new construction in Ontario creates enough excess soil to fill 16 Rogers Centres annually. (Tina Mackenzie/CBC)

"Unfortunately it's a scenario that's common around the watershed," he explains.

It's the disregard for local wetlands and fertile fields that most bothers Kapeleris.

"Supposedly it;s the best farming soil around, so why are you dumping on it," she says.

New rules coming?

Both McLaurin and Baldwin say they're optimistic about new regulations approved by the previous provincial government, but not yet enacted by the newly elected Progressive Conservatives.

Those rules would require that all soil removed from construction sites be tested for contaminants. It would also put in place mechanisms for tracking where the soil is shipped.

As well, Baldwin says the new rules would increase fines for illegal dumping, and give the LSRCA more power to enter private properties that he believes are harbouring illegal soil dumps.