The Ontario government is promising to find and remediate all the mercury contamination that continues to poison people at Grassy Narrows and Wabaseemoong First Nations in the northwestern corner of the province.

"We are completely committed to working with all partners to identify all potentially contaminated sites, and to creating and implementing a comprehensive remediation action plan for the English Wabigoon River," said a statement issued Monday from the minister of environment and the minister of Indigenous relations and reconciliation.

Kathleen Wynne

Premier Kathleen Wynne met with Grassy Narrows Chief Simon Fobister and environmentalist David Suzuki on Friday but wasn't part of Monday's announcement from two Ontario cabinet ministers. (David Donnelly/CBC)

The announcement came after a meeting on Friday between Premier Kathleen Wynne, Grassy Narrows Chief Simon Fobister and environmentalist David Suzuki.

Mercury was dumped in the river that flows through the two northwestern Ontario First Nations by Reed Paper, upstream in Dryden, Ont., in the 1960s and early 1970s. Recent scientific reports show the water is still contaminated.

More than 90 per cent of the population at Grassy Narrows and Wabaseemoong First Nations show signs of mercury poisoning, according to research released in September by Japanese experts who have been studying the health of people there for decades.

'Historic commitment'

"I welcome this historic commitment and I am eager to work to make this promise a reality so that my people can enjoy our culture and our homeland in health again without fear of an invisible poison," Fobister said.

"When our fish are safe to eat, we will know that his promise has been kept."

The First Nations have been calling for a cleanup for more than 40 years and were recently joined by some of the world's leading scientific experts on mercury remediation.

Scientists such as John Rudd and Suzuki countered the premier's claim that any attempt to clean up the mercury could make the contamination worse.

Rudd is now leading the provincially funded team that will determine which remediation options are best for each of the contaminated spots along the English-Wabigoon River system that flows between the mill site and the First Nations, according the Monday's statement.

'Full and rigorous' assessment

The commitment from Ontario also includes dealing with recent revelations from a former mill worker who told CBC News about a hidden mercury dump on the old mill site.

"We are now conducting a full and rigorous mercury contamination assessment of the entire mill site, working closely with First Nations and Domtar," the statement from the province said.

"The results of the assessment will be shared with the communities."

Dryden mill

A 'full and rigorous mercury contamination assessment' is currently underway at this Domtar paper mill in Dryden, Ont., according to the provincial government. (Louis-Phillippe Leblanc/Radio-Canada)

The purpose of the assessment is to determine "unequivocally if the site is an ongoing source of mercury," according to the province, and if it is, what measures need to be taken to stop the mercury from entering the river.

The federal and provincial governments will work with the First Nations as "key partners" on the remediation work, Ontario's statement said.

As well, the governments will reform the Mercury Disability Board, established in 1986 as part the settlement of a lawsuit over the contamination. Only about a quarter of applications to the board for disability pensions related to mercury poisoning are approved.