Randle Reef project enters new phase
This summer, contaminated sediments will be dredged and placed inside a walled-off, rectangular section of the harbour that will eventually be capped
THE SECOND PHASE of the massive $138.9-million Randle Reef remediation project is set to begin as the multi-year project moves closer to being half completed.
Starting in mid-July and through the rest of this year and next, contaminated sediment will be dredged and placed inside a walled off-area of the harbour, known as the Engineered Containment Facility, which was constructed as part of the first phase of the project.
The enclosure — that encapsulates a 6.2-hectare area (about the size of seven football fields) — will ultimately be capped over and used for docking facilities. The facility has a double steel wall — with rock in-between — constructed around a section of the harbour where sediments are most contaminated with polycyclic aromatic hydrocarbon (PAH) and heavy metals.
Now, less contaminated material from around the site will be dredged and pumped into the facility.
“It’s basically like an underwater vacuum that vacuums the sediments into the facility. Then, the excess water is pumped into a treatment
facility where it is treated and pumped back into the harbour,” said Matt Graham, a sediment remediation specialist with Environment Canada.
The three-phase remediation project comes 30 years after an Environmental Canada scientist discovered a “black, oily, oozing mousse” while taking core samples from sediments near Stelco property in the harbour.
Later studies determined the area was a massive blob of coal tar, heavily contaminated with PAHs and heavy metals that were constantly leaching into the water. Eventually a plan was drafted to contain, rather than remove the contaminants.
Roger Santiago, head of the sediment remediation unit at Environment and Climate Change Canada, says “Phase 1 is wrapping up now. They have some welding work to take care of. That work is expected to be completed within the next two weeks. After that, they will spend the next month testing out the water treatment plant and the dredge.”
Last year, workers drove 33-metre sheet piles into the bay bottom forming a double wall in a rectangular shape.
High water levels complicated welding work, which is one of the reasons why some of the welding is being completed this summer.
By July, harbour watchers should see a floating dredge — and possibly second one — moving around Randle Reef, pumping sediments into the containment facility through a large hose.
They’ll also see another hose drawing water from the facility into the treatment facility on land.
Santiago said the project is something that has never been done before.
“If you look at all of the components of what we are doing here, it is a first of its kind. Various parts have been done at other sites. But never all the parts together.”