Sydney Tar Ponds cleanup will have no major adverse impacts provided mitigation measures are followed, says EIS
Dozens of scientists, engineers, and technical specialists from three environmental engineering firms say the $400-million Sydney Tar Ponds cleanup project will have no significant negative effects on the environment or on human health, provided the mitigation measures outlined in the project Environmental Impact Statement (EIS) are followed.
"Construction practices identified in the report can successfully manage all potential negative effects of the project," Gregory Gillis, senior project manager with AMEC Earth and Environmental, told a technical briefing on January 3. AMEC is the lead firm in the consortium that prepared the EIS on behalf of the proponent, the Sydney Tar Ponds Agency (STPA), for the joint panel review of the cleanup project. Two other environmental consulting firms, Jacques Whitford and ADI, contributed to the seven-volume, 3,000-page report.
"This is a very reassuring report," said Frank Potter, the Sydney native just appointed acting CEO of the STPA. "It confirms that the impact of the cleanup will be overwhelmingly positive. It will make Sydney a better place to live, work, play, and invest."
The EIS has concluded that the few disruptions that may occur during the course of the cleanup will affect only small areas for short periods of time, and all potential negative impacts can be successfully managed. In fact, says the report, the project will have positive effects on the economy of the region and nearby communities, making 100 hectares of land in the centre of Sydney available for recreation or light industry and speeding the recovery of Sydney Harbour. Monitoring during construction and operations will help check the predictions made in the EIS and enable corrective action to be taken if needed.
The overall cleanup plan is based on the use of proven technologies and includes the following steps:
*use of biological remediation techniques, including land-farming, to break down hydrocarbon contaminants in soil;
*removal and incineration (in an approved, temporary incinerator) of some 120,000 tonnes of PCB-contaminated sediment from the Tar Ponds and approximately 26,300 tonnes of sediment containing polyaromatic hydrocarbons (PAH) from the coke ovens site;
*stabilization and solidification of remaining materials using a process that mixes hardening agents like Portland cement powder into wet sediments;
*construction of permanent engineered caps;
*installation of permanent surface and groundwater controls; and
*restoration of the site for future use.
In addition to evaluating the project's impacts on standard environmental compartments such as air quality, surface and groundwater quality, land and wetlands, the marine environment, fish and aquatic habitat, and noise, the EIS examined other important factors in the environmental setting, such as noise, public safety, community health and well-being, property values, labour and economy, land and resource use (including traditional aboriginal resource use), and infrastructure and services.
At the same time, the EIS took into account the effects of the environment on the project, giving consideration to factors such as seasonal temperature extremes, flooding and potential effects of climate change, e.g. extreme weather patterns and increased sea levels and storm surges. Each environmental component was analyzed to determine its current status, possible effects due to the project, ways of mitigating these effects, and whether any remaining effects are significant.
The Tar Ponds and coke ovens sites currently have little impact on Sydney's air quality, a fact confirmed by extensive air monitoring done by the STPA. While the cleanup will even further improve local air quality, some project activities have the potential to result in odours and emissions of dust and gases.
These potential impacts will be managed in a number of ways, such as: cleaning the area around stored materials and covering these materials as needed; applying dust suppressant and paving roads if necessary; using wind screens or land covers as needed; controlling the loading and unloading of material; and enclosing the Tar Cell during excavation and filtering air from the enclosure.
Groundwater impacts are another important concern, as the project directly interacts with groundwater resources. Groundwater under the Tar Ponds and coke ovens site, and under the incinerator site, flows to surface water streams and represents a pathway to other environmental components such as human health, notes the report.
Planned mitigation measures to address potential groundwater impacts include: monitoring to ensure containment of groundwater contamination during operations; using drains to divert contaminated groundwater from streams, plus a treatment plant to treat the diverted water. Sediments in the bed of the Coke Ovens Brooke connector will be cleaned, and all groundwater collection and water treatment systems will be designed to operate for at least 25 years.
In addition to several freshwater and brackish streams, other surface waters in the project area include the new Coke Ovens Brook channels and their tributaries, designed for fish habitat. A man-made channel will be constructed through the Tar Ponds as well. The cleanup will reduce contaminants in these surface waters, although there is the potential for recontamination by inadequately treated effluents discharged from water treatment plants or as a result of incomplete cleanup.
Measures to protect groundwater quality will also be applied to surface waters, together with implementation of erosion and sedimentation control from waste and material piles. The project will also ensure that all treated discharges meet standards specified in the federal Fisheries Act, as well as acute lethality tests.
Land-based, freshwater and marine habitat will also benefit from the cleanup in the long-term, although there may be temporary disturbances during the project. The report notes that while the area hosts at least 223 species of trees, shrubs, plants, mosses and herbs, there is no diverse, unique or extensive land-based habitat within the project boundaries.
A number of actions are outlined in the EIS to minimize potential adverse impacts on all habitats, such as: conducting any necessary disturbance of bird nesting habitat (including clearing of vegetation) only during periods when birds are not nesting; maintaining incinerator emissions within regulatory guidelines; controlling erosion from waste and material piles; evaluating fish rescue operations during rerouting of watercourses; and containment of Tar Ponds material during excavation and stabilization/solidification.
The EIS also discusses the project's potential impacts and mitigating measures relating to labour and economy, the transportation network, human health, community health and well-being, and archaeology and heritage resources.
The full report has been condensed into a plain-language 27-page summary. Both are available on the STPA Web site, www.TarPondsCleanup.ca.
Public comments on the EIS are being accepted until February 16, 2006. The STPA will than have 14 days to respond to the comments, after which the joint review panel will decide whether the EIS fulfils its requirements. If so, public hearings will be scheduled. Following the public hearings, the panel will submit a report to the federal government, along with its recommendations; the report is expected to be submitted by June 30, 2006.
Comments on the EIS should be addressed to the Joint Panel Review, P.O. Box 431, Sydney, N.S. B1P 6G9.