Dear Fellow Residents
Right now the Community Liaison Committee is placing highest priority on deciding how to
clean up the contaminated sediments in the lake system. We know that the PCBs in the lakes
are already moving through the food chain. In contrast, those on the site of the former
salvage yard are at least temporarily contained.
This newsletter, our second, tells you (a) what we know about the presence of PCBs in the soils, sediments and water in our community, and (b) in general terms, what options exist to deal with the contaminated lake sediments. We also include some basic information about PCBs. In our third newsletter we will provide more detailed information about the lake clean-up options.
Thanks to those of you who took time to respond to Newsletter #1 (see Feedback). We value your questions and comments. Please note that you can talk to the Liaison Committee via phone with your community representative, fax, or regular mail. If you didn't receive a copy of Newsletter #l, call your community representative {see page 8) and one will be sent to you.
PCBs - Where and How Much?
Over the past five years, the provincial government has been working to clean up the PCB
contamination which resulted from salvage activities near Five Island Lake. Nobody knows
exactly what quantity of PCBs may have been released into our local environment. We do
know, however, that almost all of these PCBs are now in two locations: (1) on the site of
the former salvage yard, and (2) in the sediments of North Bay, and - to a lesser extent -
in the rest of Five Island Lake and Hubley Big Lake (see map, page 4). These two locations
present very different problems.
PCBs on the Former Salvage Yard Site
On the salvage yard site itself the PCBs are present in high concentrations in soil, but
are currently contained in various ways. PCBs do not readily move through the groundwater,
which can be monitored through the special monitoring wells drilled around the site
perimeter.
The situation is not ideal, but presents no immediate threat either to human health or to the environment. However, permanent solutions for the contamination on the site are definitely needed and are still very much on the Community Liaison Committee's agenda.
What PCBs are and How They Move
Polychlorinated biphenyls (PCBs) are a class of chemicals which were often used in
electrical equipment. Since 1977 the manufacture and importation of PCBs has been banned
in North America. Some PCBs are still in use but are being phased out.
There are 209 different PCB: molecules : which vary by the number of chlorine atoms. They are commonly referred to as."Arochlors" and are grouped depending on the chlorine content. In the Five Island Lake area the common Arochlor is "1260", meaning the PCBs.:are 60% chlorinated. Unfortunately, these are the most persistent in the environment.
PCBs are essentially insoluble in water. Instead, they get attached to fine soil particles and move with them along surface drainage flow paths.
In Five Island Lake, the PCBs were most often found in the top 6-l2 inches of soil and sediment of the small brook beside the site. This material traveled down the brook, finally coming to rest in, the bottom of the lake. Small organisms living at the bottom of the lake will ingest the contaminated sediment. Other predator organisms will then eat the smaller contaminated species and the slow accumulation up the food chain begins PCBs do not move from soil or sediments into plants
PCBs in the Lale System
The PCB contaminated sediments in the lakes are much less contained, even though most of
them have remained in the North Bay area of Five Island Lake. If disturbed by boats or
wave action, the resuspended sediments can move out of North Bay.
They are also moving up through the food chain, from the organisms that live in the sediments, to fish, to the wildlife that eat the fish (and, potentially, to people who ignore the health advisory notice on the back of their fishing license).
But First ...... What is a ppm?
When PCBs are present in soil or sediments it is most common to refer to them in terms of
their concentration, often as parts per million or ppm.
Obviously the ideal situation would be to have no PCBs in the environment. Unfortunately this is rarely so. PCBs have such a long life before they break down that they have been found all over the globe, though usually in very low concentrations.
Existing federal legislation requires PCB contaminated material to be removed, stored or destroyed. To help make decisions about contaminated land or water, governments have developed various guidelines relating to clean-up goals or acceptable exposure levels. The following table shows three of the guidelines potentially applicable to the situation in Five Island Lake.
PCB Guidelines in Canada and the U.S.
Clean-Up Guidelines
Soil - 5 ppm residential or (on land) parkland land (Canada)
- 50m commercial or industrial land (Canada)
Sediment - 1 ppm (US Superfund (in water) Clean-Up Criteria) Accepcable Exposure
Levels
Fish - 2 ppm in tissue for consumption of edible portion of commercial fish (Canada)
The clean-up goals for a site can vary depending on how the Iand, surface water, or groundwater will be used. For example, the guideline for residential land is more stringent than for commercial land because residents could be more exposed to the PCBs in the soil (children playing in the dirt or people gardening, for example).
The guideline for sediments (the material that settles out and collects at the bottom of a lake or river) are more stringent than for land because aquatic organisms are more exposed and more sensitive to PCBs in their environment.
What's On and Around the Site
The Department of Transportation and Public Works has capped the former salvage yard with
a cover of over 2 feet of clay to prevent rainwater leaching through the contaminated
material underneath, and a layer of gravel to prevent surface erosion. Beneath this cap
are highly contaminated soils (concentrations of PCBs well over 50 ppm, and other
contaminants), along with old debris, scrap metal, and ash. The Department has also
cleaned up PCB contaminated soil from neighbouring properties around the salvage area,
including Western Brook. They removed soil with PCBs over the 5 ppm guideline set by the
federal government for residential land. Most of this contaminated material was in the top
12 inches of soil. Sediments in the.brook were cleaned up to 1 ppm.
Soil contaminated with PCBs above 50 ppm is regulated as a hazardous material and as such must be placed in steel containers which are inspected monthly. The soil contaminated with PCBs between 5 and 50 nPm is not considered a regulated material but is being contained in two specially constructed berms on the site. A berm is an above ground earth structure lined and capped with a layer of material that will not let water pass through (in this case the layer is clay). PCBs do not readily dissolve in water and there is no indication that they have migrated in the groundwater from the general area of the former salvage yard. However, sampling of nearby wells has shown the presence of other contaminants, primarily solvents and metals, in low concentrations (below limits set by drinking water standards).
Therefore since 1994, the provincial government has provided homes close to the salvage yard with an alternative piped source of water. Groundwater monitoring around the perimeter of the site will continue, both because these contaminants were found, and because there are still highly contaminated soils on the former salvage yard site.
The health risks depend on the type of contact between an individual and the chemical - how much and for how long: Scientists agree that sustained high level exposure (eating highly contaminated food for a long period of time for example) can result m health problems, but in the Five Island Lake area residents are not being exposed to PCBs in this way. Scientists also agree that short term, low level exposure is unlikely to have significant health impacts. There is less certainty about the effects of long term low level exposure. Currently scientists are investigating the impacts of PCBs in connection with both human fertility and cancer, but no links have been proven. However, the only way Five Island Lake residents could be exposed to PCBs over an extended period of time would be through regularly eating contaminated fish (several meals a week, throughout the year).
Once PCBs become widely dispersed in the environment, however, there is almost no way to recapture them. They take a very long time to break down and tend to accumulate in fatty tissues, posing a real risk to many species of wildlife and aquatic organisms.
What's in the Lake System
PCB contaminated sediment has been found in Five Island Lake and Hubley Big Lake. Sampling
carried out in 1994 and I996 suggests that 70-75 percent of the total PCBs in Five Island
Lake is found in the upper 12 inches of sediment in North Bay. The total affected area of
North Bay is 5 hectares (50,000 square metres). PCB concentrations in that area range from
10 to 200 ppm.
Beyond the old railway bridge, where water flows into the main part of the lake, sediment contamination declines. PCB contaminated sediment above 1 ppm (a clean-up guideline used in the US, Canada does not have an equivalent guideline) is found over an area of about 16 hectares. Throughout the rest of Five Island Lake and Hubley Big Lake PCB concentrations are below 0.5 ppm. The water in Five Island Lake has been tested and no PCBs were detected, except in North Bay where very low concentrations (less than 0.00005 ppm) have been found in the water column. These PCBs are probably attached to tiny sediment particles suspended in the water.
Cleaning Up the Lake System: Key Questions
The Community Liaison Committee agrees that the next step should be to deal with the
contaminated sediments in the lake system. The Committee also believes that while a total
clean-up cannot be achieved - that is, the removal of all PCBs from the lakes - the
current situation can, be vastly improved. The three key questions to be answered are:
1) Should the sediments be removed from the lake system or contained where they are?
2) How far should the clean-up extend? PCI3s have been found in both Five Island Lake and Hubley Big Lake but are concentrated in North Bay (an estimated 70 percent of the total PCB load).
3) If the sediments are to be removed, what should happen to them once they are on land? Many things have to be taken into consideration, but the Community Liaison Committee recognizes that cost will be a big issue. A cheap clean up option is no bargain if it doesn't make a significant difference or isn't permanent A very costly clean up option may achieve even less if funding is never found to implement it.
Typical Methods For Cleaning Up Contaminated Sediment in Lakes.
There are three basic approaches to dealing with contaminated sediments:
l. Manage the Site
Do not disturb the sediment, but restrict uses (both to avoid stirring up the sediments,
and to reduce people's exposure to the PCBs) and continue to monitor the area (water,
birds, fish etc).
2. Cover the Sediments in Place
Stabilize the material in the lake by covering it to prevent contact with the organisms
that live in the sediments or the water.
3. Remove the Sediments
Remove, then either store or treat and dispose of the sediment.
Before selecting a clean-up approach, the following questions must be answered:
Does it comply with applicable legislation?
Is it effective in both the short and long term?
Is it technically feasible?
Does it have acceptance both in the community and with government?
Is it cost effective, considering both short term and long term expenses?
Options for Five Island Lake
The Liaison Committee has started to look at three broad options (two involve leaving the sediments in place, one involves sediment removal).
North Bay or Further?
At present, all three options concentrate on North Bay because most of the PCBs are still
in this small, shallow, and fairly contained bay at the head of Five Island Lake (4
percent of the total lake area but containing 70 percent of the PCBs). The remaining PCBs
are scattered over a much wider area (96 percent of the total lake area but only 30
percent of the PCBs).
The cost of cleaning up the PCBs is closely related to the volume of the sediment that has to be either covered or dredged and treated, whether it contains high or 1ow concentrations of PCBs.
Therefore the cost of cleaning up the last 30 percent of the PCBs in the rest of Five Island Lake would be many times highte than the cost of the first 70 percent in North Bay because larger volumes of sediment are involved, even though contamination levels are much higher in North Bay.
If Dredging is Chosen, What Then?
The third option, sediment removal, is more complicated because it raises the question,
what do you do with the sediment when it’s out of the lake. There may be three
possible answers:
Build a permanent disposal berm near the former salvage yard site.
Ship all of the sediments out of province for destruction or permanent disposal.
Treat the sediments locally by either destroying the PCBs or extracting and concentrating them before sending them for destruction. Once the PCBs have been extracted, the remaining sediments must also be dealt with. Newsletter #3 will provide more information about the implications of the dredging option. In this newsletter, we talk first about the pros and cons of leaving the sediments where they are or of removing them. We would like to hear your opinions.
When Will We Be Able to Eat Fish Again?
The bad news is that whatever option is carried out, the health advisory notice would
probably still apply to fish caught in Five Island Lake and other lakes for a very long
time. No technology can remove 100 percent of the PCBs from the sediments. There will
still be residual PCBs in the sediments which will move through the food chain. However,
if 70 percent or more of the PCBs can be removed or isolated this will considerably reduce
the overall environmental impact.
Option l: Managing. the Sediments in Place
This option involves the construction of a permanent control weir (a barrier restricting
most of the flow out of North Bay) at the railway bridge where North Bay opens out into
the rest of the Five Island Lake. Western Brook would also be redirected. Swimming and
boating in North Bay would be permanently restrictcd.
This would be the lowest cost option.
Positive Features
Reduces risk to people by restricting possibility of direct contact with sediments in
North Bay.
Reduces movement of the contaminated sediments downstream by
(a) limiting flow over the control weir, and
(b) restricting recreational uses that could stir up and resuspend the sediments.
Limitations
A large quantity of PCBs will still be in the lake system, and accessible to fish and
wildlife.
Permanently diverting Western Brook and constructing a control weir will accelerate
eutrophication in North Bay (a process causing nuisance odours and algae growth)
No recreational use will be possible in North Bay.
Requires long term monitoring of chemical, physical and biological conditions of lake.
May not comply with federal legislation.
Option 2 Covering the Sediments In Place
This option also leaves the contaminated sediments in place but covers them up. Western
Brook would be diverted and a control weir built at the railway trestle, but these would
be temporary measures. A geotextile fabric would then be placed over the sediments,
siltation barriers would be placed around work areas and a slurry of sand and water pumped
in, possibly from a small floating barge. Once the sand had settled it would form a layer
about half a metre thick. The layer of sand would be monitored periodically to ensure that
it had not been disrupted. When the covering was completed, the control weir would be
removed and Western Brook restored:
Detailed cost estimates have not been prepared for this option yet.
Positive Features
Prevents both people and aquatic organisms from coming into contact with PCBs.
Prevents further movement of PCB contaminated sediments into other parts of the lake
system
Provides good short term and moderate long term effectiveness if well
monitored.
Limited recreational use may be possible in North Bay.
Limitations
Does not eliminate PCBs from lake sediments.
Damage to the geotextile fabric could allow contaminated sediments to escape.
Could kill aquatic life in North Bay while installing geotextile fabric and sand layer.
The sand layer in shallow areas could be eroded by wave action, ice action or recreational
uses.
The sand layer will reduce the area and depth of North Bay, taking away habitat and
possibly speeding up eutrophication (a process causing nuisance odours and algae growth).
Some recreational uses may be restricted in North Bay (eg, power boating)
Geotextile and sand layer requires long term maintenance, inspection and repairs.
Requires long term monitoring of chemical, physical and biological conditions of lake.
May require an Environmental Impact Assessment which would delay action.
May not comply with federal legislation.
Option 3: Sediment Removal, Treatment and Disposal
This option would again require stream diversion and a control weir, both of which would
be temporary. Siltation barriers would be placed in the lake, and about the top 30- 45
centimetres of the lake sediment would be dredged out, probably using suction technology.
This would remove an estimated 15,000 cubic metres of sediments (a single dump truck holds
about 10 cubic metres). The water in the resulting slurry would be separated out and then
treated before being returned to the lake. There may be several options for sediment
treatment and disposal, and these will be discussed in Newsletter #3.
Again, detailed cost estimates have not been developed yet and are likely to vary greatly depending on the selected on-land treatment/disposal component.
Positive Features
Permanently removes significant portion of the total PCB load from lake (depending on area
dredged)
Minimizes changes to the area and volume of the lake
May allow unrestricted recreational use for swimming and boating
Provides good short and long term effectiveness
Limitations
Experience elsewhere has shown that it is very difficult to clean up sediments to below 1
ppm PCBs - there is always a little bit left after dredging.
Does not eliminate the impact of PCBs on fish, birds or mammals due to residual in main
lake and North Bay.
May require an Environmental Impact Assessment which would delay action.
Something has to be done with the sediments once they are out of the lake! (Look for
Newsletter #3 to discuss this issue in detail)
Feedback
A number of people responded to Newsletter #1. Here is a selection of their comments and
questions. We have tried to answer the questions with the help of advice and information
from the Departments of Transportation and Public Works, Environment and Health.
Comments
Thanks for the interesting newsletter
I am glad the (liaison) committee is holding together and is still getting information
out to the community
Good newsletter - thank you
keep up the newsletter. Great Work. Thanks
Regarding the newsletter, WELL DONE!
We have just purchased a property in Three Brooks.
We were aware of the PCB situation beforehand but were disconcerted
to hear the latest media blitz just 2 days after our closing - happy housewarming!
Questions
Q. When will the North Bay clear-up start?
A. As soon as an acceptable and feasible plan has been developed, and regulatory
approval and funding secured. The Community Liaison Committee would like to see work start
as soon as possible. If the chosen cleanup method has to go through a provincial
environmental assessment this could take up to two years.
Q. What is going to be done with the 49 containers of highly contaminated
soil?
A. The Department of Transportation and Public Works has informed the Liaison
Committee that the 49 containers form a temporary, registered PCB storage facility. Right
now there are no specific plans for the disposal or destruction of the contaminated
material inside the containers. This issue will be addressed following the clean-up of
North Bay. In the meantime, the storage site is inspected every month by an independent
consultant as required under provincial PCB regulations.
Q. The 49 containers contain only a small percentage of the contaminated
soil. What is to be done about the contamination under the layer of capped clay and gravel
A. The Department of Transportation and Public Works has informed the Liaison Committee
that no decision has been made regarding removal and disposal or destruction of this
material. It is currcntly contained by a clay cap which is protected from erosion by a
gravel covering. There are monitor wells surrounding the salvage yard which are monitored
every six months to determine if the contamination is moving. Additional well
installations are planned for this fall. No effective remediation is possible in this area
until after the containers have been removed.
Q. What are the property owners in the area to do about the effect of bad
publicity on property values?
Q. What has been done to get information to real estate agents and members of
the local media? Those two groups play a major role in shaping perception and reputation
and hence property/resale value.
Q. How serious in the impact on property values: 5%, 10%, 20%? Does it vary
between different properties in the area?
Q. If and when the clean-up is completed will there be sufficient publicity to
offset the stigma affecting property values? What guarantee could a buyer expect fram a
seller? What compensation could be expected?
A. We received a number of questions relating to this issue. The Liaison Committee is very
concerned about impacts of the PCB contamination on property values. We don't have answers
to these questions. Our main mandate is to develop an acceptable clean-up and management
program. This is where most of our effort has gone and it should eventually help the
property value situation. Our other mandate is to get clear and accurate information out
to local residents and other interested parties.
Q. Are deep wells more or less likely to be affected by PCB contamination?
A. The NS Department of Environment has inforrned the Liaison Committee that there is no
indication that PCBs have moved off the site of the former salvage yard. PCBs do not
easily dissolve in water but typically remain attached to soil or sediment particles.
Therefore wells in the Five Island Lake area, outside the immediate vicinity of the former
salvage yard, do not appear to be at risk, whether deep or shallow.
Q. I would like to get my well water tested. Who do I contact?
A. A number of labs in Metro can test well water for the presence of PCBs and other
contaminants. The cost of analyzing a sample for PCBs will probably exceed $100. For more
information on whether such a test is needed (see previous question) contact thc NSDoE
Central Regional Office, 424-7773.
Q. Have PCBs been stored on other properties in the area?
A. The NS Department of Environment has investigated a number of complaints about
possible hazardous materials on other properties. So far, no other PCBs have been found.
If you would like more information on this issue contact the NSDoE Central Regional
Office, 424-7773.
Q. Is Black Point Lake safe?
A. Black Point Lake is upstream from the former salvage yard site. It appears that
the PCB contamination only spread downstream from this site. Sediments in Black Point Lake
have not been tested but 5 sampling sites were tested in Frederick Lake in 1994 (the next
lake downstream). No PCBs were detected (the detection limit for the test used was 0.05
ppm, see next question).
Q. Have PCBs been. found where Woodens River enters into St Margarets Bay?
A. Yes, in very low concentrations. Environment Canada sampled sediments in six
lakes in the Woodens River watershed earlier this year. PCBs were detected in the
sediments of Dolly's Pond, the last lake in the watershed before St Margaret's Bay, at
concentrations of 0.0055 ppm (the test used had a lower detection limit than the test used
in Frederick Lake, see previous question)
Q. What actions is the Province taking to (a) determine how PCBs have and are
being handled elsewhere in the province, and (b) prevent such contamination in the future
A. The NS Department of Environment has a comprehensive inventory and tracking
system for PCBs in use and in storage. The Department is also actively promoting the
removal and destruction of PCBs currently in storage.
A Message From The Woodens River Watershed
Environmental Organization
The Woodens River Watershed Environmental Organization (VTRWEO) is a volunteer
organization comprised of some fifty citizens committed to protecting and improving the
Woodens River Watershed. Five Island Lake is one of nineteen connected lakes, including
Upper and Lower Sheldrake Lakes, Frederick Lake, Hubley Big Lake, and Albert Bridge Lake,
which flow southwest into the Woodens River and finally into St. Margaret's Bay at Woodens
Cove in Seabright.
One of the goals of the organization is to prepare and implement a community-based Environmental Plan to meet the needs and aspirations of the residents, landowners, and other users of the watershed. This plan will enable citizens who care about the watershed to have a say in government planning for the area.
0ther goals are (1) to raise community awareness of local environmental issues and to encourage feedback from the community and (2) to coordinate with like-minded groups in the area, such as the Five Island Lake Community Liaison Committee.
The PCB problem is one of many issues that concern the quality of the local environment. WRWEO is monitoring the levels of phosphorous and nitrogen in the upper lakes. These nutrients, present in fertilizers and sewage, increase the level of plant life and lower the level of oxygen needed to support fish like trout and salmon.
WRWEO is also working on ways to improve fish habitat in the Woodens River and has, with financial support from local businesses and the Nova Scotia government, employed local high school students to identify, improve, and map recreational trails.
If you wish to be involved in these or related projects, please come to our meetings. WRWEO meets every two months, and meetings are announced in The Masthead. For further information, call Richmond Campbell at 876-7847 (evenings).
The Five Island Lake Community Liaison Committee
The CLC consists of eleven volunteer representatives appointed by local homeowners and ratepayers associations, and representatives of the Departments of Environment and Transportation and Public Works.
The co-chairs are John Hoyt (resident) and Gordon Roche (NSDoE).
The mandate of the Committee is to:
Help the community and the government exchange information and discuss concerns
Work with government to develop a remediation plan that will be environmentally sound,
technically viable and acceptable to the community.