Tar Ponds Project Narrowed to 14 Finalists

?TRANSPORTATION/PUBLIC WORKS--Tar Ponds Project Narrowed to 14 Finalists

Fourteen finalists have been selected from among 31 North American consortia interested in demonstrating that they have technologies capable of cleaning up the Sydney Tar Ponds.

The Nova Scotia Department of Transportation and Public Works now will ask the 14 finalists to submit proposals for what is known as bench-scale testing to determine their effectiveness and costs. The finalists were selected after a screening process conducted by Vaughan Engineering Ltd. The Vaughan firm was hired by the province acting on a resolution from the Joint Action Group (JAG). JAG is a partnership of community members and three levels of government working toward cleaning up the tar ponds.

"We want to make sure we have the right technology or combination of technologies to clean up the tar ponds sediment," said Ron Russell, Minister of Transportation and Public Works. "Moving forward with the bench-scale program will allow us to determine the effectiveness of the different technologies."

Vaughan examined the 31 proposals and looked at worldwide data from nearly 900 projects where these technologies were used.

In the bench-scale demonstrations, sediment samples -- about 100 litres each -- will be extracted from the tar ponds and shipped to the firms for testing. Vaughan will independently evaluate the results. A tender by invitation for this phase is expected shortly.

The 14 firms proposed a variety of cleaning methods, often combining technologies. Among them are: thermal desorption, pyrolysis, incineration, plasma, solvent extraction, bioremediation, encapsulation, stabilization/solidification, soil washing and chemical treatment.

"We are pleased with the progress of Vaughan Engineering on the technology selection process" said Dan Fraser, chair of the Joint Action Group. "We look forward to bringing the results of the bench-scale tests to the community as soon as possible."

The technology demonstration program is part of a $62 million tar-ponds agreement cost-shared by the federal and provincial governments and Cape Breton Regional Municipality.

The 14 finalists are based in Canada and the United States. They are: UMA Industrial Processes Ltd.; Colmac Resources Inc.; IT Corp. (two proposals); TDEnviro Inc.; AMEC Earth and Environmental Ltd.; DRL-UXB Canada Joint Venture; Acres International Ltd. and Roy F. Weston Inc.; Safety-Kleen Ltd.; Science Applications International Corp. (SAIC); Geo-Con Inc.; Kipin Industries Inc.; Surbec-ART; and URS/Powertech/Grace Canada Inc.

The final report on the bench-scale demonstrations is expected to be ready by this fall. It will be presented to JAG members and the community for input.

The Sydney Tar Ponds contain about 700,000 tonnes of contaminated sediments left over from a century of steelmaking and other industrial activity.

NOTE Here is a backgrounder explaining the technologies submitted:

Thermal desorption: This technology involves gradually heating the material to hit the boiling points of the various contaminants. Once vaporized and condensed, these contaminants can be separated and treated. Lower temperatures are used on organics found in sewage waste or petroleum. Hotter temperatures are applied to polycyclic aromatic hydrocarbons (PAHs) or polychlorinated biphenyls (PCBs).

Pyrolysis: Contaminated waste is dried, starved of oxygen and heated in a pressurized kiln or hearth to over 430 @C. This causes organics like PCBs and PAHs as well as dioxins (chemical compounds that can result from industrial combustion involving chlorine) to break down into gases which can be recovered and treated. What's left includes water and oil, which can also be treated, along with a solid residue of carbon and ash for disposal.

Incineration: A widely used technology in which a fuel source and oxygen are used to heat waste material to temperatures up to 1,200 C. That's enough to destroy contaminants, leaving ash residue and off-gases which can then be separated, treated and disposed of safely.

Plasma: Material is zapped with electricity, producing temperatures as high as 28,000 C, instantly destroying contaminants. Any metals melt and then cool into a solid for recycling or disposal. Solvent extraction: A solvent is used to dissolve contaminants so they can be separated from waste material. The solvent can be recycled, while the contaminants are treated and disposed of safely. This process is typically used in combination with other technologies.

Bioremediation: Micro-organisms such as bacteria, fungi or yeast are added to naturally break down organic contaminants into harmless substances. It's a very slow process that's often sped up by boosting levels of oxygen and nutrients. Encapsulation: A chemical sealant is injected in and all around the target material, sealing, solidifying and neutralizing the contaminants. Re-treatment may be needed if the coating wears down over time. Stabilization/solidification: Contaminated material is hardened with heat or chemicals into a mass so solid that water can't penetrate it, and contaminants can't leak out.

Soil washing: Contaminated material is immersed in a water-based solution with additives to dissolve or concentrate contaminants which can then be siphoned off and treated. This process works on metals, fuels and other organic contaminants. Water used in the process is treated before disposal.

Chemical treatment: This process is used specifically on material contaminated with metals, PCBs or PAHs. Chemicals react with the contaminants and break them down to a point where they can be separated, recovered and further treated. Sometimes heat is added to speed up the chemical reaction