Detailed cleanup plan launches EA process for Sydney Tar Ponds, coke ovens site project
Public Works and Government Services Canada (PWGSC) and the Sydney Tar Ponds Agency (STPA) have just released a detailed description of the ten-year plan to cleanup the Sydney Tar Ponds and coke ovens. The 200-page cleanup plan, produced by AMEC Earth and Environmental, was developed jointly by Environment Canada and the STPA.
Its release kicks off the environmental assessment (EA) process for the project required by federal and provincial legislation. PWGSC, the lead federal agency for the project, has determined that the project meets the requirements for a comprehensive study assessment track. (Other responsible authorities in respect of the EA include Environment Canada and Transport Canada.)
Accordingly, PWGSC has released for public comment a scoping document outlining the factors to be considered in the environmental assessment. The document discusses the scope of the assessment, the factors and the scope of the factors to be considered, and the ability of the comprehensive study to address issues relating to the project. PWGSC will accept comments until March 9, 2005, and is holding a series of public open houses on the scoping document this week at four locations in the Sydney area.
Comments can be made by phone, at 902/564-2534, FAX 902/564-2597, E-mail firstname.lastname@example.org, or surface mail to Public Works and Government Services Canada, PO Box 1280, Station A , Sydney NS B1P 6J9. More information, including the detailed cleanup plan, open house schedule and feedback comment form, may be found on the STPA Web site, http://tarpondscleanup.ca.
After reviewing the public input, PWGSC, together with Environment Canada and Transport Canada, will submit its findings to the Minister of Environment, who will decide whether the assessment will continue by way of a comprehensive study or a review panel.
The cleanup plan developed by Environment Canada and the STPA is based on hundreds of scientific and engineering studies, along with public consultations carried out since 1996. The overall strategy comprises six work phases, including the use of a temporary, dedicated incinerator to destroy 120,000 tonnes of PCB-contaminated sediments and surrounding sediments from the Tar Ponds, 1,300 tonnes of PAH-contaminated sediments from Coke Ovens Brook and 25,000 tonnes of PAH-contaminated material from the in-ground tar cell. The cleanup plan proposes to excavate or dredge, then dewater these materials before transporting them to an incinerator to be set up off-site.
The preferred location for the proposed incinerator is the Victoria Junction wash plant, as it offers a number of the features required for operation of the incinerator, including rail access and a reliable electrical power supply. Other acceptable sites include the Phalen Mine, North Head and the old landfill site. The plan includes a description of the process used to select the proposed incinerator sites.
The incinerator design will be tailored to the project parameters, although the plan notes that rotary kiln technology is most commonly used for the types of materials and contaminants found at the Tar Ponds and coke ovens sites. Operation of the incinerator would comply with federal mobile PCB treatment and destruction regulations as well as applicable guidelines and standards established by the Canadian Council of Ministers of Environment (CCME). A destruction removal efficiency of 99.9999% would be required as well.
The other cleanup strategies are summarized as follows.
Control of surface water at the Tar Ponds and coke ovens sites and groundwater at the coke ovens site: At the TarPonds, this will involve the construction of watercourse diversion channels to redirect surface water and so isolate brooks and streams from contaminated Tar Ponds sediments. At the coke ovens site, diversion channels and barrier walls will be installed to reroute both surface water and groundwater. This will facilitate the removal and cleanup of contaminated materials, prevent further contamination of surface water and minimize water treatment requirements.
In-situ treatment of selected contaminants at both sites: At the Tar Ponds, the top one to two meteres of sediments remaining following removal of material for incineration will be solidified and stabilized by means of augers or grout injection systems, using a binder such as Portland cement. At the coke ovens site, 253,700 tonnes of remaining PAH-contaminated surface soils will be treated by means of landfarming, a form of bioremediation. Landfarming of the top one-half metre of contaminated soil will be used to promote biological breakdown of contaminants in the surface soils.
Containment of residual contaminants at both sites: Low-permeability barrier walls will be installed around the perimeter of both sites, along with an engineered cap for the Tar Ponds and a soil cover at the coke ovens site designed to facilitate future site use(s).
Site surface restoration and landscaping at both sites, in a manner compatible with natural surroundings and future site uses.
Development of long-term monitoring and maintenance plans for both sites: Air and water quality, sediment, biota and the performance of the containment system will be monitored for 25 years after the cleanup project is completed.
The project timelines are as follows: engineering design and environmental assessment work between 2004 and 2006; elimination of PCB contamination and contamination of the tar cell and Coke Ovens Brook between 2006 and 2010; cleanup and capping of the Tar Ponds and coke ovens site between 2006 and 2013; and decommissioning of facilities in 2013.