Fish return to Sydney, N.S., brooks after $400-million industrial cleanup

SYDNEY · Fish are returning to the waterways around Sydney's former industrial sites, a positive sign following a $400-million cleanup of waste left by a century of steel and coal production. The remediation was overseen by the Sydney Tar Ponds Agency, now part of Build Nova Scotia, which continues to monitor water quality in the area. Donnie Burke, a senior director with the agency, said independent engineering reports confirm the work is effective. "Everything that we're seeing to date is trending stable or improving, so that's a wonderful thing," Burke said.

The cleanup involved encasing the notorious tar ponds, once considered Canada's most toxic site, in concrete and covering the adjacent coke ovens ground with slag rock. Three brooks running through the area were cleaned, and the landscape was reshaped to direct surface water into them. Groundwater from the coke ovens site is treated before being released back into the brooks. Both sites were then capped with topsoil and grass, creating new public spaces.

Regular water testing indicates the concrete cap over the tar ponds is successfully containing toxins, Burke said. At the former coke ovens site, heavy metals or chemicals sometimes spike after heavy rainfall, but the monitoring system detects these events and the treatment process is adjusted. "There's all kinds of little anomalies," Burke noted. "We see a little more fluctuation here, but for all intents and purposes, this has been stable or improving since the cover has gone on."

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The remediated land now includes Open Hearth Park, with sports fields and walking paths, and an open field used for activities like cricket and snowmobiling. A recent Cape Breton University study found a small fish species had returned to the brooks. Provincial staff have also observed trout eggs and young fish in Coke Ovens Brook. "Who would have thought that 20 years ago, that trout would live here?" Burke said.

Katherine Jones, a biology professor at CBU, had previously studied mummichog fish that showed poor health in the contaminated tar ponds. A pilot study she supervised last year found those fish no longer display the earlier symptoms. "We didn't see fin rot or fin erosion or bone abnormalities, so overall, the state of the health of these fish seems to be much better than prior to the remediation," Jones said. Jones said more research is needed to understand if fish are still affected by the sites and to learn if current populations are descendants of past residents or new arrivals. The provincial government committed to 25 years of post-cleanup monitoring, with results publicly posted online. Burke said the program is about halfway through its term. "And everything seems to be trending in the right direction," he said.

With files from CBC News