Five Island Lake

Five Island Lake
Community Liaison Committee
Newsletter #8, December 1999

Dear Fellow Residents ….

Five years ago the Five Island Lake Community Liaison Committee held its very first meeting. Probably none of us expected back then that we would still be meeting on a regular basis as we get ready to enter the 21st century, but at least we can mark our fifth birthday in the knowledge that the clean-up of North Bay has begun in earnest. Weather permitting, the clean-up contractor will have finished the delta area at the outflow of Western Brook and removed almost a third of the contaminated sediments from North Bay by the middle of December.

But we won't be celebrating until the job is complete. This will require the government to commit funds in the next budget and the tendering of a new contract to complete the dredging and disposal.

The Liaison Committee agreed to a phased clean-up over two years in recognition of the Province's tight financial situation. But there is no way to completely isolate the newly dredged area from the rest of North Bay. A really big storm with winds blowing from the northeast (luckily the prevailing storm winds come from the opposite direction) could stir up the remaining contaminated sediments and redistribute them back to the "clean" side of North Bay. Therefore, it is essential that the second phase of the dredging start as early as possible next spring.

We hope we can count on continued support from government to see this project through. We always appreciate receiving your thoughts via feedback form, e-mail or a phone call.

Containment Cell Not Needed After All

When we sent out the last newsletter, before the contract for the first phase was awarded, we anticipated that it would be necessary to store the dredged and dewatered sediments in an interim containment cell (a lined and covered on-land storage area). The good news is that the containment cell was not needed after all. The selected contractor, Safety Kleen On-Site Inc, has been able to transport the dewatered sediments directly to one of two disposal facilities in Quebec and still stay within the available budget.

How the Contractor is Getting the PCBs out of North Bay

Different areas of North Bay present different challenges. Along the shoreline, and near the delta in particular, Safety Kleen decided to do some of the work "in the dry". This involved lowering the water level in the Bay, which is possible because it is separated from the rest of Five Island Lake by a control weir.

The contractor then installed a temporary water-filled barrier called the "Aqua Dam" (if you visited the site you would have seen something that looks like a long white sausage).

On the shore side of this barrier the contractor pumped the water level even lower, and then used high-pressure hoses to wash the contaminated sediments along the rocky edge of the Bay into the middle where they can be more effectively collected and removed. This was much more efficient than trying to dig around the rocks or manoeuvre the dredge in the very shallow areas. This part of the clean-up has now been completed and the In the wetland areas at the outlet of Western Brook (now diverted for the duration of the clean-up), the contractor used excavators and backhoes to remove the contaminated surface soils. Around some of the big trees that can be preserved, the contractor dug the soil out by hand. The final restoration of this area (placing new topsoil and seeding) will take place next spring to avoid frost damage.

In the deeper water, a small floating dredge called a Mud Cat is used to remove the sediments.

All of the wet sediments are processed through a mechanical press to remove as much water as possible and make the material suitable for transportation. It is then sampled, and loaded directly into trailers. Dewatered sediments that have concentrations of PCBs below 45 parts per million (and so far, this includes everything) are being sent to a special landfill site in Trois Rivieres operated by Horizon Environmental. If any material has concentrations greater than 45 parts per million, it will be sent to Bennett Environmental Inc's thermal desorption facility in St Ambroise.

Environmental Controls

Silt curtains (very fine meshed material that lets water through but stops most of the suspended sediment particles in the water) have been installed on either side of the control weir, and also across North Bay, dividing the area that is being cleaned this year from the rest of the Bay.

The process water that comes out of the mechanical press is tested before returning it back to the lake and must meet the freshwater aquatic life standards approved by NS Department of Environment. The same tests are applied to water pumped out of North Bay to lower the water level. The Department is also monitoring water quality every day in the main part of Five Island Lake just on the other side of the control weir.

High Rainfall Caused Temporary Problems

So far, the environmental controls appear to have been working well and there has been no evidence that the clean-up has had any adverse impacts on the water in the main part of Five Island Lake. However, in October, when the contractor had lowered the water level in North Bay by pumping, several days of high rainfall caused a dramatic rise in the water level on the other side of the control weir in the main part of the lake. As a result of this pressure, water from the main lake started to find its way through the fill embankment supporting the former rail bridge. Safety Kleen immediately stopped pumping water out of North Bay and added new rock fill to the embankment to stabilize it.

The result of all of this was that the water in North Bay become very muddy, mainly from fine material washing off the new rock fill and sediments washing out from under the old rail bed. The Department of Transportation's consultants (Jacques Whitford) are confident, however, that very little of the PCB contaminated sediments on the bottom of North Bay got stirred up and resuspended.

Safety Kleen had to suspend clean-up operations for a few days until the suspended sediments settled out and the water was clear again. Although this caused some delays, the contractor has made adjustments to their schedule and still intends to be finished with this phase of the clean-up by mid-December.

Restoration

Once this phase of the clean-up is complete, very little restoration work will be needed. The bottom of North Bay will gradually collect a new layer of clean sediments and will be re-colonized by plants and aquatic animals. At the outlet of Western Brook, however, a thin layer of clean stone will be placed over a small area because there may still be very small amounts of contaminated sediments in the crevices between boulders that cannot be retrieved. The protective stone layer will limit the likelihood of aquatic life having access to these sediments.

The abandoned rail line has been used as the access road to the North Bay site and as a staging area for all of the clean-up equipment. Because the long term plan is for the old rail line to become a multi-use trail, the Department of Natural Resources, in consultation with the St Margarets Bay Rails-to-Trails Association, has agreed that the trail can be re-aligned through the delta area. Trail users will benefit from a more scenic route.

Want a Closer Look?

If any local resident wants to have a closer look at the clean-up operations, Jacques Whitford is willing to make arrangements for a short tour of the clean-up site and equipment at North Bay. Call Sean Margueratt at 483-2337 (cell) or 876-7371 (site phone).

Community Representatives on the Five Island Lake Community Liaison Committee

Richmond Campbell, Cambrians Cove 876-7847

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 823-3068