Tar ponds cleanup moves closer to solidification, stabilization

By Debbie Gwynn
Cape Breton Post
Fri., May 16, 2008

Sydney - Before moving ahead with the full scale solidification and stabilization of the cooling pond project a small field demonstration was carried out in January 2008.

The Sydney Tar Ponds Agency held an open house Thursday to update residents of the Cape Breton Regional Municipality with the results of the testing.

The field demonstration, led by Chris Holt, senior remediation engineer with Earth Tech, helped engineers to select which mix recipes would work best on the cooling pond sediment when the full-scale solidification and stabilization technology is applied.

Twelve cells were treated during the testing. The total volume of contaminated sediment treated was about 1850m3 (enough sediment to fill about 2,100 domestic oil tanks). "This is pilot-scale work and is needed before we can go ahead with full scale solidification/stabilization," said Tanya Collier MacDonald, communications officer for the tar ponds agency, "where they (Earth Tech) show their results meet the criteria regulators have identified before moving ahead with the full scale project."

Members of Sierra Club’s Cape Breton Group issued a press release Thursday demanding the results of bench scale testing of the stabilization and solidification of the Sydney tar ponds sludge completed in May 2007, be released to the public immediately.

"This technology holds no promise of success with tar ponds sludge," said Dan McMullin, chair of Sierra Club’s Cape Breton Group in the release. "Once again, government will squander hundreds of millions on a proposal that may well make matters worse."

Reports from the testing carried out in 2007 along with results from the pilot-scale work will be sent to the regulators, Nova Scotia Environment and Public Works and Government Services Canada upon completion.

Collier MacDonald anticipates it will be four to six months before all results are in, the regulators approve it and the agency can move forward. "We will release the results of the reports of the bench-scale and pilotscale work at that time," said Collier MacDonald.

Although exact figures were not available, Collier MacDonald believes that during peak construction periods approximately 120 people will be involved on the construction side of the project — but added the numbers will fluctuate.

Upon approval, full-scale stabilization and solidification of the Sydney tar ponds is expected to be completed by 2014.


Chris Holt (left), design engineer with Earth Tech, fields questions from concerned citizens on the proposed plan of solidification and stabilization of the Sydney tar ponds. The group gathered at a Sydney Tar Ponds Agency open house at the Royal Canadian Legion Branch 12 in Sydney, Thursday. From right, chair of the Sierra Club of Cape Breton Group Dan McMullin, former Frederick Street resident Debbie Ouellette, Aubrey Rodgers, Marlene Kane and Richard Barrington. Steve Wadden - Cape Breton Post


The pre-selected performance criteria included the measuring of the following characteristics:
  • Strength - results were typically 3-4 times greater than specified criteria.
  • Permeability (the ability for water to pass through the treated sediment) - results confirmed that the treated sediment was impermeable and surpassed all criteria requirements.
  • Leachate (the ability for contaminants to be released from the treated sediment)- results easily achieved adopted criteria.