The Sydney Tar Ponds were a hazardous waste site on Cape Breton Island in Nova Scotia, Canada. Located on the eastern shore of Sydney Harbour in the former city of Sydney (now amalgamated into the Cape Breton Regional Municipality), the Tar Ponds formed in a tidal estuary at the mouth of Muggah Creek, a freshwater stream that empties into the harbour. Throughout the 20th century, runoff from coke ovens associated with Sydney Steel Corporation's (SYSCO) now-decommissioned steel mill filled the estuary with the typical variety of coal-based contaminants and sludge. Efforts to clean up the waterway were dogged by false starts, delays, and political controversy. The coke ovens closed down but 12 years later, the toxic mess remained. After extensive public consultation and technical studies, a