Ontario vows transparency as testing at Dryden, Ont., mill site continues

Officials with Ontario's Ministry of the Environment say all "methods, data and results" from an ongoing probe at the site of a Dryden, Ont., mill will be made public.

The assessment that's underway at the complex in Dryden is attempting to answer whether it is a continuing source of mercury contamination for the English-Wabigoon River system.

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"The site assessment is being completed through a transparent process that includes the involvement of First Nations," said Gary Wheeler, a spokesperson for the Ministry of the Environment and Climate Change in an email to CBC News.

"As part of this process, all methods, data and results from the assessment will be transparently shared with First Nations, stakeholders and members of the public," he continued.

"The ministry is of the view that all information related to mercury at the site and in the rivers should be transparently shared."

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That will include a 2016 report completed by True Grit consulting and commissioned by Domtar, the mill's current owner, Wheeler said. The study attempted to determine if mercury is still making its way from the property into the nearby Wabigoon River. Grassy Narrows First Nation and Wabaseemoong Independent Nations are located downstream from the site.

Both communities have had a long history of mercury poisoning dating back to when Reed Paper, one of the mill's former owners, dumped several tonnes of the toxic chemical element into the river in the 1960s and early 1970s. Residents of both communities became sick from eating fish caught from the waterway.

The report prepared for Domtar noted that elevated levels of mercury have been recorded on the property over the years, particularly around a former chlor-alkali plant that used mercury as part of its process. However, the study noted that data available as of 2016 was insufficient to determine if mercury is still leaching into the river and recommended further study.

A team of scientists has already released a report suggesting ongoing mercury contamination is happening.

Premier says Domtar report 'new information for me'

While the environment ministry is pledging transparency in how the results of ongoing studies will be shared, Ontario Premier Kathleen Wynne told reporters Wednesday she was only told recently about the engineering report commissioned by Domtar.

The company said it provided the findings to the province in July 2016.

"The specifics of this latest report are new information for me," she said, adding that "we're not sure exactly how that ... information hadn't made it to my desk."

"We're asking that question."

Site work in Dryden continues, environment ministry says

The investigation recommended by True Grit in its report continues, the ministry said, adding that heavy equipment is being used to install new groundwater monitoring wells which will be tested; as well, soil samples are being taken.

The True Grit report noted that a number of wells have existed on the property over the years but some have been "lost or destroyed," and others "may not have produced quantitatively reliable data" based on their construction or depth.

The ministry said those existing wells were installed by company owners prior to Domtar "for their own purposes," and environmental officials weren't aware they existed until 2016 when Domtar provided the province with historical data from them.

Domtar took ownership of the complex in 2007.  A spokesperson told CBC News in an email that the company can't speak to "the purpose, quality or relevance of ... historical data."

"This [ongoing] work will allow for a better understanding of groundwater characteristics and flow patterns on the mill property and help assess whether there is an ongoing source of mercury to the river," the statement from the environment ministry said.