The federal and Nova Scotia governments say contaminants in the former north and south Sydney Tar Ponds have been contained in cement.
Close to 872,000 tonnes of contaminated material have been contained — about the equivalent of stacking up 112 football fields, each a metre deep.
Work began in October to build a park on top of the former hazardous waste site, and the governments say the park is expected to be open to the public in the fall of next year.
They say the cleanup projects remains within its $400-million budget and is scheduled to be complete by March 2014.
The site contains industrial toxins from decades of contaminants spewed from the former Sydney Steel Corp. plant.