McGuinty said the Adams mine proposal faces two formidable hurdles.

"We have to have a full environmental assessment, not one that has been narrowly scoped," McGuinty said.

"Secondly, we need the approval of the community that will be affected."

The proposal to use the Adams mine as a dump primarily for Toronto's trash resurfaced this week after the Environment Ministry tentatively approved a water-taking permit for the mine's owner.

The draft approval would allow the company, owned by the Cortellucci family, to pump millions of litres of water a day from the mine near Kirkland Lake.

Ministry documents show that the aim of draining the pit is to enable the company to prepare the site to receive garbage.

The project - endorsed by the previous Conservative government - has already received approval under the Environmental Assessment Act.

However, critics have long argued that assessment was fundamentally flawed because it was far too narrow - a process implemented by the Tories known as "scoping."

"There's all kinds of other evidence by experts that suggest this thing would leak and contaminate the farmers' fields and the water in the area perhaps for hundreds if not thousands of years," said New Democrat Marilyn Churley.

"It's a disaster waiting to happen. This application should have been pulled."

After days of emotional debate in 2000, Toronto voted to truck its trash to Michigan rather than to the mine, and the project appeared dead.

Nevertheless, the idea of using the mine has never gone away despite widespread opposition from area farmers, native groups and environmentalists.

Natural Resources Minister David Ramsay said today he would resign if the project proceeds.

"I could not stay in government if the Adams mine becomes a garbage dump," Ramsay said.

McGuinty said it's premature to talk about such a move, saying he would rather go ahead with an expansion of recycling in the province.

"If we could just divert all of our organics, our table scraps and yard waste and the like, that would take one-half of the trucks off the road that are travelling to Michigan at present," McGuinty said.

"There's a lot more that we can do right here on our own."

Tory John Baird said the Liberals are discovering how tough some of the issues are to deal with, pointing out the Michigan border could close to Toronto's garbage and precipitate a crisis.

That's why the previous Conservative government backed the Adams mine proposal, Baird said.

"What we're seeing now is the government realizing the hard realities of being in government," Baird said.

Environment Minister Leona Dombrowsky would only say the government was reviewing its options.

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