Notable case, Sydney, Cape Breton, Nova Scotia, Canada
Sydney Tar Ponds
An estuary that for nearly a century received the effluent of Sydney's coke ovens and steelworks: about 700,000 tonnes of sludge with PAHs and PCBs. After a failed first attempt at incineration, it was stabilised with cement.
Contaminants
Organic compounds
Status
Contained
The sediment was solidified and stabilised in place with cement; work ended in 2013 and the area is now Open Hearth Park. The contaminants remain in place, immobilised.
Story
Sydney's steel plant opened in 1901 and produced until 2000; the coke ovens closed in 1988 after 88 years, and a Domtar coal-tar plant ran from 1903 to 1962. Effluent drained into the estuary, where about 500,000 tonnes of contaminated sediment built up; a further 560,000 tonnes of contaminated soil lie on the coke ovens site.
A first project in 1986, costing $34 million, was to dredge and incinerate the sludge: it was abandoned in 1995 because of pipeline failures and other technical problems. In 2004 the federal and provincial governments committed $400 million to solidification and stabilisation with Portland cement, completed in 2013.
Timeline
- 1901The steel plant opens.
- 1986First dredging and incineration project.
- 1988The coke ovens close.
- 1995The incineration project is abandoned.
- 2004C$400 million funding announced.
- 2013Work completed; Open Hearth Park opens.
Health
Wikipedia reports a cancer rate for the Sydney area 45% above the Nova Scotia average; the figure has not been checked against a primary source.
Remediation
- 2013solidification/stabilisationIn-place mixing of the sediment with Portland cement (contract awarded 2009, work completed 2013).
Plants and fungi at this site
Microbial bioremediationField scale
Landfarming on the coke ovens site: soil treated with hydrocarbon-degrading bacteria. Wikipedia mentions it as the only biological method used in the project, without dates or results.
- Sydney Tar Ponds, en.wikipedia.org, 2026
From the literature
Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.
Plants
- Medicago sativaAlfalfa, lucernePolychlorinated biphenylsPolycyclic aromatic hydrocarbonsEvidence: field
- Cucurbita pepoZucchini, pumpkinPolychlorinated biphenylsEvidence: field
- Populus × generosaHybrid poplar (P. trichocarpa × P. deltoides)Polychlorinated biphenylsEvidence: field
- Lolium perennePerennial ryegrassPolycyclic aromatic hydrocarbonsEvidence: greenhouse
- Miscanthus × giganteusGiant miscanthusPolycyclic aromatic hydrocarbonsEvidence: greenhouse
- Morus spp.MulberryPolychlorinated biphenylsEvidence: laboratory
Fungi
- Funneliformis mosseaePolycyclic aromatic hydrocarbonsEvidence: greenhouse
- Irpex lacteusMilk-white toothed polyporePolycyclic aromatic hydrocarbonsPolychlorinated biphenylsEvidence: laboratory
- Pleurotus ostreatusOyster mushroomPolycyclic aromatic hydrocarbonsPolychlorinated biphenylsEvidence: laboratory
- Agaricus bisporusButton mushroomPolycyclic aromatic hydrocarbonsEvidence: laboratory
- Bjerkandera adustaSmoky bracketPolycyclic aromatic hydrocarbonsEvidence: laboratory
- Cladosporium sphaerospermumPolycyclic aromatic hydrocarbonsEvidence: laboratory
The rest are on the contaminant pages.
Sources
- Sydney Tar Ponds, Wikipedia, 2026
Draft compiled from public sources, not yet reviewed.