The Ontario government is conducting expanded mercury testing around the site of an old paper mill in the province’s northwest in the hopes of cleaning up an area that has left a First Nation plagued with mercury poisoning for more than 50 years.

The commitment follows testing done by volunteers with an environmental group last year that found high levels of mercury in soil samples taken near the mill in Dryden, Ont.

The Grassy Narrows community, near the Manitoba border, has dealt with mercury poisoning since the mill dumped 9,000 kilograms of the substance into the Wabigoon and English River systems during the 1960s.

But mercury concentrations haven’t decreased in 30 years and dangerous levels are still present in sediment and fish, causing ongoing health and economic impacts in the community. Researchers have reported that more than 90 per cent of the people in Grassy Narrows and the Wabaseemoong (White Dog) First Nation show signs of mercury poisoning.

The Ontario government previously conducted testing near the mill, when a former worker came forward to say he had buried more than 50 barrels of mercury and salt in a pit in 1972.

No barrels were found, but volunteers with the environmental group Earthroots later found high levels of mercury in soil samples.

After those results were made public, the government said their tests had been conducted in a different area, so it is now testing the entire mill site.

“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,” Ontario Environment Minister Glen Murray and Indigenous Relations and Reconciliation Minister David Zimmer said in a statement.

“We need to be sure unequivocally if the site is an ongoing source of mercury, and if it is, then we need to work with partners to take all measures to stop further mercury from entering the river.”

Ontario Premier Kathleen Wynne and the province’s environment minister met Friday with the chief of Grassy Narrows and environmentalist David Suzuki.

Judy Da Silva, the environmental health co-ordinator for Grassy Narrows and a member of its mercury working group, was skeptical but hopeful that the new commitment would lead to action.

“With elections getting close for the province of Ontario I’m kind of wary of anything actually happening and I guess I’ll believe it when I see it,” she said. “To me, when I hear full assessment of the entire mill site and committing to identify and remediation plans, to me it all sounds like words…I’m hoping I’ll live to see the day it is cleaned up.”

Ontario NDP critic Michael Mantha said the people of the Grassy Narrows and Wabaseemoong First Nations have waited far too long for the government to act.

“The NDP caucus will be watching closely to ensure there’s follow through on these commitments, and my colleagues and I will continue to press the Liberal government on this promise until the fish are safe to eat,” he said.