Canada's federal environment commisioner is warning that contaminated sites will cost taxpayers billions of dollars. There are more 22- thousand sites in Canada.. and while some have been cleaned up.. there are many that still hold environmental and health risks.

Yellowknife's Giant Mine is a toxic time bomb.
Buried in underground frozen chambers are tonnes of poisonous arsenic tailings -a byproduct of gold mining.
But the permafrost is melting. So taxpayers are footing the bill to keep those tailings permanently frozen.
It's a familiar story for the Environment Commisioner.

WHEN YOU LOOK AT THE THE LEGACY OF CONTIMINATED SITE RIGHT ACROSS THE COUTNRY THIS IS A LEGACY THEY WILL BE PAYING FOR FOR CENTURIES"

Canada has more than 22-thousand contaminated sites.. they're aren't just in places like the north..
They're in cities like Toronto, Montreal. Here in Ottawa for example there are 150 contaminated sites.

And there's a huge price tag
The report says it will cost $7.7 billion dollars to clean up the contaminated sites
The cost could rise because many sites still have to be assessed.

"THESE ARE HEAVILY CITIES POPULATED PEOPLE COULD BE LIVING BESIDE THESE CONTAMINATED SITES WITHOUT EVEN KNOWING."

The sites range from spilled fuel to abandoned industries...many happened before Canada brought in stronger environmental laws.

But Scott Vaughn drew a parallel between the old problems and controversial plans in the federal budget to streamline environmental laws.

"IT'S CAUTIONARY TALE.. IN MOVING FORWRD LETS MAKE SURE WE DON'T RETURN TO THE PAST AND CREATING NEW CONTAMINED SITES AND NEW BILLIONS DOLLARS OF LEGACYS

The government says it has already cleaned up 9000 sites"

Meanwhile back in Yellowknife officials are still working out how they'll keep keep toxic waste frozen for centuries.
The estimated price tag at this point.. 400 million dollars.