Tar ponds will get boring
Engineers need to drill into bedrock beneath north and south ponds
By Tanya Collier Macdonald
Cape Breton Post
Wed. Jan. 10, 2007
SYDNEY - Bedrock under the tar ponds will get numerous pokes over the next
eight weeks as engineers try to get a firmer grasp on what lies
underground.
"They burrow a small hole, it's probably about two and a half inches in
diametre," said Wilf Kaiser, acting director of environmental services for
the Sydney Tar Ponds Agency. Air emissions aren't expected, "but in
keeping with our approach, we'll definitely be doing real-time air
monitoring specific to this activity."
Kaiser said although there are likely small fractures, there is little
risk that contamination will be released from the ponds.
Maritime Testing Ltd., a Dartmouth firm, and Boart Longyear Inc., a
Moncton company employing a local driller, will use a barge-mounted drill
rig to collect 39 core samples from both the north and south tar ponds.
Earth Tech and CBCL will oversee the job.
Although samples were previously taken from the ponds, that work focused
on sludge settled on the bottom of the tar ponds, not the bedrock.
This time, crews will drill 1.6 metres deep and extract samples in areas
along the same route that's been selected to channel water from Coke Ovens
Brook and Wash Brook. The channel will provide a clean path for water
travelling through the tar ponds and into Sydney harbour.
Project manager Joe Sullivan said the samples will provide crucial
information needed when the walls of the channel are anchored to the
bedrock.
Results will influence the final design of the sheet pile wall.
The channel design will use the western shoreline of the tar ponds to form
one side of the channel and the eastern side will be built using
interlocking steel sheet pile.
The barge is expected to arrive at the site Friday and drilling will
likely begin Monday.
tcmacdonald@cbpost.com
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