Contaminated hot spots in the seabed around the Esquimalt Graving Dock are 10 to 20 times higher than todays standards allow.
The primary source has been historical industrial activities such as shipbuilding and repair, when work practices were not as carefully managed as they are today,
Contaminants include metals such as arsenic, copper, lead, and zinc), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), said Ruslan Tracz, spokesman for the federal Department of Public Works and Government Services.
Bids are being solicited for a $44-million plan to dredge and take away more than 80 years worth of contaminated sediment and materials at the federally owned graving dock.
The area from which the contaminated sediments will be removed was selected to minimize the Government of Canadas risks and financial liabilities to the greatest extent possible; virtually the entire water lot has contaminant levels exceeding federal and provincial standards, and the hot spots have levels 10 to 20 times higher than the standards, Tracz said.
The highest contamination areas are at the mouth of the graving dock and under and around the south jetty, he said.
Dredging will be the second phase of remediating the 85-year old graving dock where work has been carried out on military and civilian vessels. The value of the project is expected to be about $44 million, the federal government said.
Work will be done at the graving docks water lot and a further area running 30 to 50 metres past the legal boundary, he said. The intent was to include all areas that may contain contamination from historical operations at the graving dock.
In September, Victoria-based Salish Sea Joint Venture won a $6.5-million contract to build a pile wall to stop erosion, the first of three phases in the project.
There is no hazardous waste identified in the water lot area that will be dredged as part of this project. A limited amount of hazardous waste-level contamination has been identified in the area to be contained within the steel sheet pile wall that will be constructed as part of the current project. The containment will allow this portion of the remediation to be undertaken at a future date. Tracz said.
The contractor will dredge about 149,630 cubic metres of contaminated material that will be taken to a licensed land-based disposal facility.
Current operations are required to comply with existing environmental legislation and standards, he said.
To reduce risk from work at the graving dock, environmental management best practices are in place to provide added protection to the marine environment. These practices are taken very seriously and regularly undergo evaluations for continual improvement. he said.
In addition, a separate $101 million in federal money to be spent on modernization over five years. Private companies such as Victoria Shipyards, now refitting frigates and upgrading submarines, lease the graving dock.
© Copyright 2013