Tar Ponds cleanup project should be approved, but site may need permanent monitoring, says panel
Remediation of the Sydney Tar Ponds is unlikely to be a permanent, "walk-away" solution. While the coke ovens site, once cleaned up, may eventually need no further monitoring or maintenance, there is a distinct possibility that the Tar Ponds will have to be managed in perpetuity, says the joint federal-Nova Scotia panel reviewing the proposed project.
Its environmental assessment (EA) report on the proposal submitted by the Sydney Tar Ponds Agency (STPA) has concluded that overall, the project, together with the technically and economically feasible means of carrying it out, are unlikely to result in significant adverse impacts, provided the recommendations made by the panel are implemented and subject to the results of a risk-benefit analysis conducted under the terms of Canada's toxic substances management policy.
The report by the independent three-member panel includes 55 recommendations addressing a full range of environmental, technical and socio-economic issues relating to the project. The prospect of managing the Tar Ponds site in perpetuity is one of four key findings arrived at by the panel in the process of reaching its overall conclusion.
Although the STPA envisioned the cleanup as being permanent, the report says the Agency, as well as regulators and the public, should be prepared for the possibility that the Tar Ponds site will require monitoring and/or maintenance indefinitely.
The use of proven technologies to deal with the contaminants on the sites is a cornerstone of the project plan, with containment designated by the STPA as the primary technology for remediation and solidification/stabilization applied as a secondary approach. The panel says it is not convinced that the latter technology is proven for use in the context of the Tar Ponds cleanup, i.e. dealing with organic contaminants in organically enriched sediments, situated in an estuary with potential groundwater and seawater influx.
Accordingly, the report calls for further pilot studies to be done and specific targets reached before solidification/stabilization technology is approved for use in the project.
The panel says the use of incineration on the project is technically feasible, subject to appropriate technology selection and stringent regulation. This conclusion, however, is tempered by the panel's acknowledgement of the community's concerns about the use of incineration and awareness of the stress and anxiety that introduction of this process would induce.
The report notes that Canada's toxic substances management policy requires the federal government to conduct a risk-benefit analysis of in-situ treatment versus removal of contaminated material for off-site destruction. The requirements of this analysis have only been partly met, says the panel, adding its view that a full assessment might favour the "full containment, no incineration" approach proposed by STPA over incineration.
Finally, the report notes that while future uses of the sites is not part of the project, its overall design must ensure that the sites have the capacity to support viable, sustainable uses.
Heading the list of recommendations is approval of the project by the Nova Scotia Minister of Environment and Labour, subject to conditions addressing the report's recommendations. Secondly, the federal and provincial governments should ensure that mitigation measures proposed by STPA as an integral part of the project are put in place.
In the course of its review, which included 17 days of public hearings during April and May, the panel heard about concerns relating to the management and monitoring of air quality impacts associated with excavation, landfarming and solidification/stabilization activities during the cleanup. Consequently, a number of recommendations address, in some detail, further work on estimating total air emissions, a pilot study to examine the potential air quality impacts of the solidification/stabilization process, and requirements for a comprehensive monitoring and follow-up program.
In response to concerns raised about the capping of the Tar Ponds site and extensive areas of the coke ovens site, the report includes recommendations addressing the design, function, durability and monitoring of the caps. The panel has also recommended that the need to undertake landfarming activities at the coke ovens site be re-evaluated, in view of public concerns about air quality effects and the STPA's own information about the uncertainty of success and potential effects on some bird populations.
The report notes a prediction by the STPA that the remediation work will cause a temporary increase in contaminant loadings into Sydney Harbour, to be followed by a significant and permanent decrease once the containment work is complete. The panel has agreed with the federal departments of Environment, of Fisheries and Oceans and of Natural Resources that the STPA should complete an ecological risk assessment for the harbour and further recommends that the Agency collaborate with the three departments in long-term monitoring of improvements in the harbour's water quality.
The STPA has made no decisions as yet about the type of incinerator to be used, and might possibly consider using more than one unit. The Agency carried out extensive health risk assessment studies and its proposal includes measures to prevent and mitigate malfunctions, upsets, spills or other incidents.
Nevertheless, the panel recommends that as a first step, the STPA should conduct a risk-benefit analysis to assess how in-situ management of PCB would compare to removal and destruction by incineration, in terms of ecological and human health effects. If this analysis points to incineration as the preferred approach, the panel has made a series of recommendations to ensure the safe design, operation and regulation of the incinerator.
Once decisions have been made about the exact technology to be used, the report says the STPA should revisit air dispersion and health risk assessment studies to determine what, if any, changes should be made in their conclusions. It also recommends the identification and use of best available techniques and environmental practices and increased regulatory capacity.
With regard to environmental management of the project, the panel notes that regulating it will be a challenge both because of its size and complexity and the mix of jurisdictional responsibilities involved. Accordingly, a recommendation calls for the federal and provincial governments to develop a formal agreement for sharing expertise and co-ordinating regulatory processes.
The panel further recommends that provincial legislation be put in place to guarantee long-term, continuing maintenance and monitoring of contaminants on the sites. The Tar Ponds and Coke Ovens Remediation Maintenance and Monitoring Act would include provisions for reporting and accountability and would specify under what conditions maintenance and monitoring could cease. The panel also recommends that the federal or provincial governments retain ownership of the capped portions of the cleaned up Tar Ponds and coke ovens sites until a cap monitoring program (called for in another recommendation) confirms the integrity of the cap.
Both governments will now take the time required to carefully review the joint panel's recommendations. Nova Scotia Environment Minister Mark Parent will consider the panel conclusions and recommendations and will make public his decision on the project pursuant to the Nova Scotia Environment Act. The federal government (with Public Works and Government Services Canada as the lead department) will prepare a response to the report and submit it to the governor-in-council for approval. The decision will then be made public.
A summary of the report, including all the recommendations, may be viewed on the Canadian Environmental Assessment Agency Web site, www.ceaa-acee.gc.ca.