Tests confirm Sonic non-thermal process as feasible for destroying Tar Ponds PCB
Sonic Environmental Solutions reports that treatability studies done on samples of PCB-contaminated materials from the Sydney Tar Ponds using the company's non-thermal technologies successfully destroyed PCB to a non-detectable level in samples taken from the Tar Ponds.
The results of the tests, conducted at Cape Breton University (CBU), were detailed in a report by CBU presented to the federal-provincial joint panel review hearings on the Sydney Tar Ponds cleanup environmental assessment (EA). CBU was an intervenor at the hearings, which began April 29 and ended last week.
Dr Jane Lewis, a dean at CBU, said the goal of the tests was to present an unbiased scientific review of the science behind the proposed methods. In the evaluation of Sonic's technology, the report stated that there was no detectable PCB following Sonic's destruction process. Consequently, she said the Sonic process offers an alternative to incineration for PCB destruction and a viable, proven non-thermal alternative available to the Sydney Tar Ponds Agency (STPA).
Based in Vancouver, Sonic offers Terra-Kleen, a solvent extraction technology for the removal of persistent organic pollutants (POPs) and the Sonoprocess technology for the chemical destruction of POPs. The company develops proprietary Sonoprocess applications using the enhancement of sonic energy generated by its patented industrial-scale sonic generator technology.
Results of the study are available on the joint federal-provincial review panel Web site, www.stpco-review.ca.
The STPA's cleanup plan proposes the use of incineration to destroy up to 125,000 tonnes of PCB-contaminated sludge from the Tar Ponds. Public opposition to PCB incineration of PCB was a key factor leading to the formation in 2005 of the joint review panel for the project EA.
During three weeks of public hearings, the three-member panel heard presentations from some 25 groups, organizations and individuals, beginning with a presentation from the STPA as the project proponent.. The STPA's proposal to incinerate the PCB-contaminated sludge using state-of-the-art technology, is supported by various federal departments, along with CBU and local business and community groups. Opponents of the plan include residents of Grand Lake Road, near the site proposed for the incinerator, and the Sierra Club.
The panel is scheduled to complete its report within the next two months.
Meanwhile, a Nova Scotia company, J&T Van Zutphen Construction, of Port Hood, has been awarded $1.4-million contract for the construction of a rock barrier between the Sydney Tar Ponds and Sydney Harbour. The project is one of four preliminary preventive works intended to prevent environmental damage during preparations for the overall remediation.
"This project marks an important step in preparation for the big cleanup," said Barbara Baillie, director of engineering services for the STPA. "The Battery Point barrier will be essential in preventing the spread of sediments into Sydney Harbour once work begins in the Tar Ponds themselves," she explained.
Consisting of a rubble mound breakwater, the barrier will extend from Battery Point in the north end to the shoreline near the Provincial Energy Ventures property in Harbourside Commercial Park (formerly Sysco). It is designed to prevent contaminants from flowing into the harbour during cleanup of the Tar Ponds.
A 50-metre gap near the midpoint will accommodate water flowing through the Muggah Creek estuary. Reinforced structures, lined with thick steel and filled with slag, will anchor the two sides of this gap.
Van Zutphen will first place a rock mattress across the bottom of the pond, then construct the core of the barrier using steel plant slag. A layer of geotextile fabric will cover the core, followed by a layer of coarse stone. To protect the structure from waves and ice, its harbour face will be lined with armor stone.
Design of the Battery Point barrier, by the engineering firm CBCL, included extensive computer modeling of surface water to ensure that the project does not aggravate flooding in the Townsend Street area of downtown Sydney.
Van Zutphen will begin work on the barrier by June; it should completed by the end of October.
Other preventive projects include: relocation of the Whitney Pier water main, completed last fall; the relocation of Coke Ovens Brook, which began last summer and will be wrapping up this fall; and the cleanup of the Sysco Cooling Pond, which is currently out to tender.