Historical water pollution along north shore being covered over: research

Monitoring data showing that pollution from mill effluent being covered over in Terrace Bay, Marathon, Ont.

originally posted on November 26, 2016


Environmental monitoring in a pair of north shore communities is showing some good news in terms of ongoing mitigation of historical industrial pollution, according to the Thunder Bay Remedial Action Plan.

Members with the group are involved with the monitoring and remediation of several sites of concern in the Thunder Bay area and along the north shore.

The action plan’s co-ordinator, Jim Bailey, said data was presented from provincial and federal environmental agencies this fall concerning two sites — one in Terrace Bay and the other in Marathon.

In Terrace Bay, the information showed that historical pollution, largely from untreated effluent from the local mill decades ago that ran into a creek that feeds Jackfish Bay, is being covered up by natural processes, including sedimentation.

“That’s not to say that anybody’s quantifying that environmental recovery is indeed taking place, rather they just presented data to show that some of this legacy contamination is actually being covered over,” he said, adding that actual cleanup efforts along the 15 kilometre stretch of creek as well as the bay would likely cost over $100 million.

“Although there was contamination in the creek and also in the bay, it just wasn’t practical to clean up,” he said.

When the toxic runoff was first dispatched into the waterway, Bailey said there were no laws in place saying it couldn’t be done.

“It’s not that environmental regulations were lax, there were no environmental regulations. So, that’s a lot different than nowadays, all the effluent regulations are being met.”

Artificial barrier in Marathon harbour working: Bailey

Further east in Marathon, Bailey said that monitoring around a type of cap that was put into Peninsula Harbour in 2012 is showing some good results.

A chemical plant that used to be attached to the former mill in the community dumped mercury into the harbour decades ago, he said.

The $7 million cap is designed to speed up the naturally-occurring sedimentation process, Bailey said.

The former mill in Marathon, Ont. used to have a chemical plant nearby that dumped mercury into Peninsula Harbour decades ago. (Jeff Walters/CBC)

“A process … to get this sediment layer … down on top of this contaminated area would have [naturally] taken decades and decades, and they estimate something like 70 years,” he said.

“That process was accomplished in one summer, with this laying down of this material,” he said.

In the aftermath of those efforts, Bailey said aquatic vegetation and other small organisms are beginning to re-colonize the area.

Additional monitoring data is expected to be compiled in another two years, Bailey said.

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