The Canadian and Nova Scotia governments have announced a $400-million plan in Sydney, Nova Scotia to clean up the famous “Sydney Tar Ponds” hazardous waste site The new plan involves encapsulation and capping the toxic materials — the residue of more than a century of steel-making and coke-production. Ottawa will provide up to $280-million for the cleanup and with the province will put in $120-million. The plan also drops a dimension that would have seen some of the waste incinerated.
The Sydney Tar Ponds are considered the worst contaminated waste in Canada. The pit holds about one million tonnes of toxic industrial by-products. Nearby residents have complained for years about noxious odours and health concerns, including high cancer and birth-defect rates.
The latest cleanup scheme follows previous failed attempts to rehabilitate the site. In 1986, Ottawa and Nova Scotia announced they would dredge and incinerate the waste; the project came to a stop after it was determined the incinerator couldn’t burn PCBs. Another plan, also involving burial of the contaminants, was announced in 1996 but went nowhere.
In the new plan, engineers will build two kilometres of channels through the tar ponds to allow clean water to pass through without transporting contaminants. The major portion of the cleanup will occur between 2008 and 2012; sediments in the tar ponds will be stabilized and solidified using a process that involves mixing the sediments with cement powder and other hardening agents. Those areas will then be covered with a cap consisting of a high-density polyethylene liner or clay, followed by layers of gravel and soil. The surface, in turn, will be planted with grass and other vegetation. Engineers will build a layered cap over contaminated sections of the coke ovens.
The announcement was welcomed by many residents, but some remain critical. Elizabeth May, federal Green Party Leader, says the proposal relies on unproven technology that poses a risk to the public’s health.
“Even if it works, we’re building a concrete sarcophagus in the middle of Sydney that will forever hold the risk of leaching toxic waste. It’s not a cleanup, it’s a cover-up,” she said. May is the former head of the Sierra Club of Canada. She added that an independent review panel questioned the effectiveness of mixing concrete with waste including coal.