EA approval for Tar Ponds cleanup opts for solidification, bans incineration
The governments of Canada and Nova Scotia have opted for solidification, containment and capping of contaminated soils as the preferred approach to cleaning up the Sydney Tar Ponds and coke ovens sites. This will be followed by site development and long-term monitoring and maintenance. Incineration has been rejected as a component of the project, and landfarming at the coke ovens site will be prohibited as well.
The decision, announced January 28, was based on careful consideration of recommendations made by the joint environmental assessment (EA) review panel. The announcement in Sydney also included formal approval by Nova Scotia Environment and Labour Minister Mark Parent of the EA for the cleanup project. Nova Scotia Environment and Labour (NSEL) will be the primary regulator of the cleanup project, and will ensure compliance with environmental approvals.
"I have carefully reviewed the recommendations of the joint panel and I am approving the Sydney Tar Ponds Agency's cleanup proposal," Parent said, adding, "My department will now closely monitor the cleanup to ensure public health and environmental protection at all times."
The Sydney Tar Ponds Agency (STPA) will still be required to obtain industrial and other approvals. These will contain detailed design, engineering and operational plans as required by Part V of the Environment Act.
The independent joint panel submitted its report to the Minister of Environment and Labour and the federal Environment Minister last July (EcoWeek July 31, 2006). The panel's report questioned whether stabilization and solidification (S&S) technology was sufficiently proven to deal with the Tar Ponds contamination.
At the same time, the panel acknowledged community concerns about incineration of the highly contaminated material, along with the STPA's information about uncertainties relating to landfarming. It thus recommended a risk-benefit analysis on S&S technology, which STPW subsequently conducted. This analysis found that S&S is safer, healthier and more cost-effective.
Parent's approval of STPA's cleanup proposal is contained in the response by the Nova Scotia government to the joint panel's report. All 40 recommendations directed to NSEL have been accepted, and are addressed through the terms and conditions of the EA approval. The Minister has also added conditions as part of the province's response to the joint panel's recommendations.
Following up on the risk-benefit analysis done as recommended, the Minister's approval further requires STPA to conduct a series of pilot-scale tests to demonstrate that S&S can be used safely and effectively on the sites. This is intended to address the panel's concerns about the use of S&S technology for materials similar to those found at the Tar Ponds and coke ovens sites.
With regard to a panel recommendation dealing with increased regulatory capacity, NSEL has committed to establishing new dedicated positions within the department with responsibility for work on the Tar Pond and coke ovens remediation project. NSEL will also carry out a panel recommendation calling for the creation of a remediation monitoring oversight board. This board will report to the Environment and Labour Minister on the department's performance as the project's primary regulator.
One of the joint panel's main findings was that the sites, once cleaned up, will likely require monitoring over an indefinite period. In response, NSEL intends to amend the activities designation regulations under the Environment Act to provide authority to establish long-term approval over site activity and to require monitoring and maintenance as long as required. The need to draft new legislation (a Tar Ponds and Coke Ovens Remediation, Maintenance and Monitoring Act) will be assessed as the project nears completion.
A summary of the provincial response document may be viewed on the Environment and Labour Web site, www.gov.ns.ca/enla/tarponds.
The agreement between the federal and Nova Scotia governments provides for diligent and cost-effective management of the remediation project. The sites will be cleaned up on a cost-shared basis over eight years for a total of $400 million, with the federal government contributing $280 million and the province, $120 million. Actual remediation work is expected to begin this spring.
Meanwhile, a core sampling program is under way in the north and south Tar Ponds, using a barge-mounted drill rig to collect a total of 39 core samples. The program is being carried out by Maritime Testing and Boart Longyear.
The core samples will give design engineers a more detailed understanding of the physical properties of the bedrock under channels to be built through the Tar Ponds this summer. The channels will provide a clean corridor for water from Coke Ovens Brook and Wash Brook to flow through the Tar Ponds to Sydney Harbour.
Previous sampling programs concentrated on the environmental properties of sediments throughout the Tar Ponds. This program focuses on a specific route, and will concentrate on bedrock. Earth Tech and CBCL, the engineering firms carrying out the final design of the cleanup, are supervising the work.
Project manager Joe Sullivan said the drilling will provide crucial information about the geology of the bedrock that will anchor the walls of the channels. The barge will drill 1.6 metres into the bedrock. "We need to know the depth at which bedrock starts, and such things as whether it is solid or fractured," Sullivan said. "That information will influence the final design of the sheet pile wall."
The main channel will stretch 2.5 kilometres from the end of Wash Brook at Prince Street, to the gap in the newly built Battery Point barrier. The western shoreline of the Tar Ponds will form one side of the channel. The eastern side of the channel will be built using interlocking steel sheet pile.
A shorter branch channel will connect the main channel with Coke Ovens Brook, on the east side of the south pond. All the channels will be designed to have a natural appearance.