Yellowknife (May 04/05) - A federal official says claims of unlicensed arsenic dumping by former Giant Mine workers is news to him.

DIAND's Mark Liskowich, head of technical and environmental services for the Giant Mine remediation project, said his group has conducted numerous studies in recent years to determine the full scope of surface contamination at the mine site, and believe they have a good idea where the problem areas are.

As for the thousands of tonnes of arsenic trioxide dust produced during 60 years of mining operations, he believes most of it is where it should be - sealed underground in chambers, or in barrels at a "secured site."

"There's no records to indicate any uncontrolled or unlicensed dumping across the property," said Liskowich.

"What we do know is that we got a good, solid understanding across the entire property."

He said he has never heard any reports of the arsenic chamber next to the B-1 pit near the smoke stack - Chamber 208 - of ever being breached in an explosion.

He said the department cleaned garbage out of the pit last summer and installed a liner to prevent water from leaching into the ground. He said rules were imposed during the mine's lifetime prohibiting blasting near arsenic chambers.

Emery Paquin, the territorial government's director of environmental protection, said his department isn't disputing claims that arsenic trioxide was illegally dumped into the tailings ponds.

The territorial government is partnering with DIAND in cleaning up the mine surface, which Paquin estimates will eventually cost taxpayers $100 million.

"Many types of waste could have been put into the tailings ponds, including barrels," said Paquin.

He said any barrels containing arsenic will likely stay there because disturbing them would be too risky.

Paquin admitted that the stability of the tailings ponds - which are full of mostly muck - is a concern.

"Tailings ponds have collapsed in other parts of the world," said Paquin.

"Again, we have to make sure they're stable for the long term."

He said the ponds will probably be capped with some sort of material, perhaps earth and sod.

The two governments plan to demolish arsenic-contaminated buildings, but they haven't decided what will be done with the demolition waste.

Meanwhile, Paquin urged anyone who may have worked at the mine and has information about contaminated areas there to contact them.

"Come forward now so they can be built into the plan," said Paquin.