Capping makes best solution
April 12, 2003
By Paul Macdougall and Michael P. Milburn
We are writing in support of Vic Dawson's letter, Workbook Exercise Important To Do (March 24). Mr. Dawson argues in favour of the containment option for cleanup of the tar ponds and makes a call for more public involvement in the options selection process.
While we strongly support the Joint Action Group process, a blanket statement by JAG that all cleanup options are "safe and effective" is not enough to help people identify the best option. All cleanup options have risks — some greater, some lesser — and there is not a long enough track record of similar cleanups to confidently judge effectiveness.
While it is likely that each technology has been shown to work in cleanup projects somewhere in the world, one thing is certain: increasing the complexity of a technology does not necessarily guarantee results. Because of the increased possibility of failure, we reject the high tech options.
Burning is not a viable option, on site or off, because of the possibility of dioxin and furan production in PCB incineration, no matter how effective the incineration is. PCB levels above 50 parts per million are considered toxic, and material with PCB levels above this arbitrary cut-off are to be dealt with separately. But what percentage of PCBs exists in concentrations of less that 50 ppm which would end up being burned at inappropriate temperatures?
Moving the material will produce noise, smell, traffic problems, disturbance of the underlying geology that has contained the tar ponds for over 100 years, polluting of the harbour — and, worst case scenario of all, creating of airborne contamination of various chemicals at both the tar ponds and the coke oven sites. Sydney has not had that since the steel plant stacks shut down years ago.
Even if the material were transported off site, the closest incinerator is in Quebec, and as of early March officials there had not been consulted about accepting PCB material from Sydney.
The general discussion has focused mainly on PCB contamination. Many other toxic materials exist at both sites, and creating aerosolization of this by digging, transporting, burning and so on is not acceptable.
The just released mortality study (Plant Pollution May Have Been Deadly: Study, March 26) suggests again that the major disease problems associated with 100 years of steelmaking (which, we remind readers, built Sydney) are linked to people who lived downwind of the stacks. Do we really want to see new stacks in any form, however small?
Recent studies (contact JAG for details) show noticeable improvement in the harbour over the past number of years, correlated with the discontinuation of the dumping of material into the tar ponds. Natural dispersal and attenuation processes are actually cleaning the harbour; the less we dump into it, the quicker it will return to its former state. (This is why we need a state-of-the-art sewage treatment system for the region, but that is another issue.)
In 1973 the first PCB-degrading bacteria (bioremediators) were reported. Since then, research has discovered many species of bacteria that can degrade PCB material. In 1998 researchers from University of .British Columbia isolated PCB-degrading bacteria from PCB-contaminated Arctic soil, but not from similar uncontaminated Arctic soil.
This is relevant on two points:
1) PCB bioremediating bacteria naturally find their way to sites of contamination; and
2) these organisms could be adapted to bioremediate in other climates.
Other studies show bioremediation
of PCBs occurs in environments both with a plentiful supply of oxygen and devoid of oxygen, such as
sediments in the bottom of ponds. Bioremediation is also used quite successfully to remove hydrocarbon
andtoxic metal pollution.
Other studies show bioremediation of PCBs occurs in environments both with a plentiful supply of oxygen and devoid of oxygen, such as sediments in the bottom of ponds. Bioremediation is also used quite successfully to remove hydrocarbon andtoxic metal pollution.
The conclusions we draw from this are straightforward. Encapsulation and containment is the best option for the tar ponds. Containment is already occurring at the tar ponds and will continue if a proper encapsulation method is used. Natural attenuation and bioremediation are already occurring and will continue to do so over the long term.
Monitoring will be needed, and there is no reason not to believe that in the future bioremediation strategies will be developed that can speed up the natural processes, which are now almost assuredly happening, simply by adding bacteria (and possibly fungi) into the mix. For the coke ovens site, bioremediation and containment is the best pick.
So we are left with leaving the material where it is, which is not as bad as some might think. This option will boost the local economy; there'll be no belching smokestacks, and no technologies that in the end may not work.
Unfortunately, very few members of the community have become involved in the options selection process. Perhaps many are confused by the complexity of options, and JAG has not done a sufficient job in highlighting the risks and benefits of each. As Pam Paruch says (Community Must Be Heard on Cleanup, Letters, April 7), "There should be thousands involved in making these choices."
So, by April 24, fill out a workbook, or do it online. And if you agree with us, vote against the high tech solutions and instead support encapsulation, containment, and long-term natural attenuation and bioremediation. We feel this is the most promising approach to take, offering the best precautions. We encourage others with similar or different views to consider writing to the Cape Breton Post.
Paul MacDougall is a microbiology technologist and instructor.