An aerial view of the Sydney tar ponds.
Tar ponds a stinky problem for officials
Controlling dam doesn't always make for sweeter-smelling Sydney
By Matt Hunt Gardner
SYDNEY - The Cape Breton Regional Municipality and the Sydney Tar Ponds Agency
have been using the coffer dam in a bid to flush smelly sewage out of the
Mike MacKeigan of the municipal public works office said the agency has kept the
dam wide open this summer, allowing the ponds' natural tides to flush out the
millions of litres of raw sewage that flow into them each day.
He said if the dam is kept closed, sewage can settle at the bottom of the ponds
and begin to break down, causing foul odours.
But leaving the dam open can cause a big stink if conditions are dry and water
levels in the pond get low. He said that's what happened in June, when the
smell of raw sewage pervaded downtown Sydney.
Frank Potter, an agency engineer, said the agency and municipality have
experimented with opening and closing the dam, trying to combat the odour. But
he said smells develop either way.
Last year, 4.8 kilometres of new sewer pipes were installed to divert Sydney's
sewage out of the ponds, in the centre of the city, and into Sydney Harbour.
But council decided not to use the new pipes until a sewage treatment plant is
built on Battery Point.
The coffer dam was built in 1993 to keep a constant pool of water over the ponds
to facilitate dredging, part of the first attempt to clean up the site.
Mr. Potter said the cleanup of the ponds over the next 10 years won't be slowed
by smells or sewage in the ponds.
The treatment plant is expected to be open by May 2005, at which point sewage
will be diverted from the ponds and the smells should disappear, Mr. MacKeigan