Five Island Lake

Five Island Lake
Community Liaison Committee

Newsletter #6, October 1998

In November, 1994, Five island Lake Community Liaison Committee was established to provide a forum for community and government representatives to work together on securing and remediating the PCB contaminated site at Five Island Lake. Our goal has been to ensure that the plan is environmentally sound, technically viable, and acceptable to the community.

In November 1996, after consultation with the community, we recommended a 13 point Cleanup Strategy to deal with the PCB contaminated sediments in Five Island Lake. This Strategy involves dredging a layer of sediments out of North Bay. The strategy laid down some basic principles to be followed in planning the clean-up. It also recognized that before final decisions could be made, more information was needed about the technical viability of some options and their costs.

In December, 1996, the Strategy was presented to Wayne Adams, then Minister of Environment, and Don Downe, then Minister of Transportation and Public Works. Since then further information has been collected on various environmental conditions in North Bay, and a boat launch and control weir have been constructed. More recently, 'bench scale'testing of PCB removal technologies has been carried out, and a pilot dredging test completed. Reports of these two activities are described below.

At the time Newsletter #5 was sent out (November 1997), we needed to obtain a response from the provincial government on funding before we could proceed with any further remediation activities. The response from the Premier indicated that the funds would not be available to support a rapid cleanup of the site, so we have had to revise our approach. We can still move forward but we recognize that the clean-up plan needs to be set in a time frame that is longer than we originally hoped. This newsletter is intended to bring you up to date with where we are now, both in terms of the long term plans we want to implement, and the next phase of activity.

We have now developed three recommendations to guide our long term planning process, and a short term proposal for action. We need to hear your views on the recommendations and action plan proposal, so please either return the feedback form or call the community representative who lives nearest you (see contact information on
page 7).

Letter from Premier Russell MacLellan, July 1998
. . . "I would like to take this opportunity to assure you the commitment to deal with the PCB contamination in the North Bay of Five Island lake is as strong as ever. I am sure you can appreciate the Province is operating on a very strict budget. This has unfortunately resulted in a temporary delay in scheduling the clean-up of North Bay.

The Province presently is looking at options for securing the funding necessary to carry out these works. Meanwhile, on-site work will continue in preparation for the removal of PCB from North Bay."

Pilot Dredge Test A Success!
The demonstration dredging project in North Bay is now complete and the results have been evaluated. The Nova Scotia Department of Transportation and Public Works, together with their contractors Laidlaw Environmental, tested different equipment and processes over a ten week period ending in early January 1998. Their goal was to see if the PCB contaminated sediments which have accumulated in the North Bay of Five Island Lake could be effectively dredged and dewatered.

The answer is yes. Using a small dredge unit, mounted on a barge, Laidlaw was able to remove a 30 centimetre layer from the top of the sediments in the lake. This material was then dewatered on land, using a plate filter press. This left a much firmer sediment 'cake' which could be easily handled and transported.

After this more highly contaminated layer of sediments (containing between 50 and 100 parts per million PCBs) was removed, the remaining sediments in the pilot test area in most cases had less than 1 ppm PCBs.

The dredging process resulted in only minimal sediment resuspension. Water quality tests carried out beyond the silt curtain showed very little variation from the normal water chemistry.

Significant Findings from the Dredge ...

  • The dredging process, using a suction cutter head, works best on an open mud or sand bottom. But good results were also obtained in weed beds by making two passes: one to remove most of the weeds, and one to dig out the root mat and the sediments.
  • Dredging on a rocky bottom, using a rotating brush system, was not effective because weed roots appeared to hold the sediments in the deeper rock crevices.
  • During the demonstration about one hundred cubic metres of sediments were removed and put through a plate filter press which filters the sediment out of the water. This produced 150,000 litres of process water and about 65 cubic metres of filter 'cake' weighing 40 tonnes.
  • The process water was very clear. It was put in containers and taken off-site for disposal by a licensed waste contractor, but tests showed that it could easily be treated and discharged back into the lake.
  • A centrifuge was also tested as an alternative dewatering technology, but it was much less effective. It left so much water in the sediments that they could not be handled without further treatment. The process water from the centrifuge still contained significant levels of suspended solids and would also require further treatment.

Lake Clean-Up Strategy: Basic Principles

Dredge the contaminated sediments out of North Bay…
There is no other reliable, long term method of keeping the PCBs from spreading further up the food chain and through the lake system.

Make sure that the dredging doesn't make things worse.
Test to make sure it can be done safely and use all necessary environmental controls.

Investigate the viability of separating the PCBs from the dredged sediments using thermal desorption.
Transporting all of the sediments (potentially enough to fill 400 dump trucks) a long distance could be prohibitively expensive and risky. Thermal desorption, a non-burn separation process (now proven to work on Five Island Lake sediments) could reduce volumes and costs significantly.

Treat the contents of the 49 containers on the site of the former salvage yard at the same time.
The containers were only intended to be a temporary solution, and they could be a problem if access was needed to the contaminated site beneath them. Therefore, if practical, the contents should be disposed of at the same time as the lake sediments are dealt with.

Send the PCBs away to be destroyed off-site
Destruction through incineration at licensed facilities is the only permanent solution.

The 13 Point Strategy: How are we getting on?
1. Focus on North Bay sediments

Jacques Whitford personnel have been collecting information on North Bay such as water depths and quality, the distribution of aquatic vegetation, and debris on the lake bottom. The pilot dredge test also took place in there.

2. Include plans to deal with the 49 containers stored on the site of the former scrapyard
This continues to be one of the criteria used to evaluate options.

3. Final strategy must meet certain criteria
Now that the pilot dredge test has shown that removing the sediments from North Bay is both practical and environmentally acceptable, we know that two of the key criteria can be met: dredging the sediments will prevent the escape of more PCB-bearing sediments from North Bay into the rest of the lake, and reduce the further movement of PCBs into the food chain.

4. Take cost into consideration after environmental, regulatory and community criteria have been met.
We do not know the exact costs for the recovery and destruction of PCB sediments, but the pilot dredge test has provided enough information to establish estimates which will assist the Province in establishing budgets to undertake full remediation of North Bay.

5. Remove contaminated sediments from North Bay
The dredge test has now proven that this is technically and environmentally feasible.

6. The removal process must not permit further escape of PCBs from North Bay
Some residents have expressed concerns that dredging could stir up contaminated sediments and allow them to disperse further down the lake. The dredge test has shown that very little of the sediment is re-suspended in the water and this can be controlled by the use of silt curtains.

7. Provide water access and construct a temporary control weir.
A new boat launch has been built for use by property owners who have lost their access to North Bay. A control weir has also been installed. Water continues to flow through the opening in the weir but, if necessary, North Bay can now be temporarily isolated from the rest of the lake.

8. PCBs in North Bay sediments should be destroyed not stored.
In Newsletter #5 it was reported that the only licensed PCB destruction facility in Canada at Swan Hills Alberta was temporarily closed. It is currently accepting shipments again, but at reduced capacity. In addition, a second facility in Quebec is now accepting PCBs. The Province continues to monitor developments in the field of PCB destruction.

If thermal desorption can be carried out (see #10) and the Quebec facility can be used, the concentrated PCB liquid could be shipped there directly after extraction.

9. The transportation of sediments to the Swan Hills incinerator is an acceptable option but costly.
Since the new treatment facility in Quebec is closer, the transportation costs would be lower. However, the overall costs are still high and require further investigation.

10. Carry out pilot tests to investigate the feasibility of thermal desorption in order to cut costs.
Thermal desorption is a non-burn process which separates out the PCBs from the sediments in the form of an oil. Bench-scale tests (using small amounts of sediments in a laboratory) have been completed. The results were so successful that the consultants have advised that further testing is unnecessary at this stage.

11. If thermal desorption is not viable, a secure containment berm should be considered but only as a last resort.
Thermal desorption is technically viable but costs are still uncertain and the process has not yet been approved for use in Nova Scotia. If the sediments are removed from the lake either before thermal desorption is approved or before funding can be secured for transportation and destruction, there may be no option but to provide secure temporary storage for the contaminated sediments on site.

12. Time is of the essence.
The Committee pressed to have the clean-up of North Bay begin in 1997 in order to reduce the risk of negative environmental effects and to restore community confidence. Another year has gone by and significant progress has been made in implementing the strategy, but the contaminated sediments are still in North Bay.

13. The Community Liaison Committee should continue to be involved.
The Committee continues to meet and monitor developments.

The Next Steps:
Three Recommendations For The Community To Consider.
The Community Liaison Committee has reviewed this new information and reached a unanimous conclusion. Now we are making three new recommendations which will form the foundation of our long term plan. We are asking you, the community, for feedback:

Recommendation #1
The pilot test has proven that the contaminated sediments can be safely and efficiently removed from North Bay. Therefore the Community Liaison Committee recommends that the Department of Transportation and Public Works prepare to let a contract to dredge the sediments as soon as funds become available. Removing the sediments from the lake is the most responsible first step in the site remediation process because every day that passes, some of the PCBs in North Bay have the potential to migrate further through the lake system or move into the food chain as they are ingested by animals that live in the lake.

Recommendation #2
The Committee's first choice is for the PCBs to be removed from the site and destroyed as soon as possible. However, we recognize that if they cannot be destroyed immediately, they will have to be temporarily stored on land. In light of the very high cost of out-of-province PCB destruction and the delay in obtaining major project funding, the Community Liaison Committee recommends that, after dewatering, the sediments should be stored in a secure temporary control berm on land. This control berm should be designed, built and monitored to meet all appropriate environmental regulations and standards.

Recommendation #3
The Liaison Committee reaffirms its commitment to the 13-point Lake Clean-up Strategy and recommends that the Department of Transportation and Public Works keep the Committee informed about developments in PCB destruction options. When a viable option becomes available the government and the community should proceed to carry out the remaining steps of the strategy is quickly as possible.

1998-9 Action Plan
Approximately $500,000 is available for clean-up activities this winter. It is proposed that the following work be undertaken:

  • Excavation of contaminated sediments from the delta in the lake at North Bay.
  • Storage of those sediments on the property in a fully engineered bermed cell to provide secure temporary storage.
  • Rehabilitation of the area disturbed by excavation activity.
  • Removal of some of the 49 metal containers from the site and destruction of their contents.

For More Information:
If you need more information, and especially if you are new to the area and want to know what the CLC is trying to do, please call the CLC member who lives nearest you. If you want to receive past copies of the newsletter, please call 423-8629.

Community Representatives on the
Five Island Lake Community Liaison Committee

Richmond Campbell, Cambrians Cove    876-7847

Andre Faubert, Lake of the Woods   876-8390

Wenda Greer, Cambrians Cove  876-0813

John Hoyt, Three Brooks   876-2722

Ken Jakeman, Lake of the Woods  876-2510

John Jardine, Five Island Lake  876-2724

Danny LeBlanc, Sheldrake Lake 876-8179

Joyce Milley, Hubley Lake Road   876-5000

Wayne Nicholson, Five Island Lake   876-2294

Murray Power, Sheldrake Lake   876-8236

Shawn Redmond, Glen Margaret  23-3068