About 100 people came to see the official opening of the Ferry Street Bridge over the former Sydney Tar Ponds site in the city's north end Saturday.

The opening of the bridge is a significant step in the $400-million cleanup of the tar ponds.

The tar ponds and the former Sydney Steel coke ovens have long been considered one of Canada's worst toxic waste sites.

At one point the site contained 700,000 tonnes of soil contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), solvents and various heavy metals.

There was a bridge there before, but it wasn't accessible while the cleanup took place.

As part of the opening, children were asked to make boats out of recycled materials.

A Mi'kmaq elder blessed the bridge in a smudging ceremony.

The 33-metre bridge is now open to pedestrians and cars will be allowed on Monday.

"The people in the [Whitney] Pier, on this bridge and on the trails in the park can commute to work in the downtown of Sydney, so a couple could get by with one car, they can cycle, they can walk, they can jog," said Alastair MacLeod, chair of the Citizens Liaison Committee for the tar ponds cleanup.

"This is something new and we're really, really proud of it."

Organizers says the cleanup, which began five years ago, is on schedule and will be completely finished in 2014.