Nunavut communication site cleanup continues
Many Canadians think of the Arctic as a pristine and unaltered landscape. However, beyond and beneath the breathtaking beauty are some of the worst contaminated sites in the country. These sites were created in the 1950s, when both the Canadian and American governments built a large number of military radar bases at isolated locations in the Canadian north. The bases were part of the United States cold war strategy to monitor and protect against the possible threat of a nuclear attack from the Soviet Union. The string of primary bases is referred to as the Pinetree Line. These are supported by a number of separate bases called the Pole Vault Line and subsequently the Distant Early Warning (DEW) Line sites.
Construction of the military radar base at Resolution Island commenced in 1951; it became operational in 1953. Resolution Island -- also known by the Inuit name "Tutjah" which means "place where a bird lands" -- is located at the southeastern tip of Baffin Island, approximately 310 kilometres southeast of Iqaluit, just outside Frobisher Bay. The U.S. Air Force left in 1972 and the base was taken over by the Canadian Coast Guard until it was finally abandoned in 1974. In 1976, the assets at the site were sold to the Government of the Northwest Territories (NWT). Today the land is administered by Indian and Northern Affairs Canada (INAC).
The only permanent residents of the island are polar bears and even these are normally seen at the site only during the summer. Other wildlife, such as seals, whales and sea birds are commonly observed around the island and along the shoreline. Inuit parties hunt and fish in the area on occasion, but no permanent settlement exists.
Environmental surveys have revealed that abandoned military bases all across Nunavut and the NWT are contaminated with PCBs and heavy metals. Remedial operations at the worst sites are being given priority.
Resolution Island has been identified as having the highest level of PCB contamination -- up to 8,000 ppm -- of all former military bases under INAC's responsibility. The contaminated soil originated largely from spills when PCBs were used as an insulator for electrical equipment. Site investigations conducted from 1987 to 1990 revealed that the soil is also heavily contaminated with mercury and lead.
In 1997, INAC along with the Iqaluit-based Qikiqtaaluk Corporation (QC) and its Montreal, Quebec-based consultants Legault Desjardins and Simon Consultants Inc. (LDS) began Phase One of the cleanup. A large-scale, long-term remediation plan was developed in cooperation with Environment Canada, QC, LDS and Dr. John Poland of the Analytical Services Unit at Queen's University of Kingston, Ontario. (See "On Thin Ice" in the December/January 2000 edition.)
PCB disposal preferred
INAC plans to remove approximately 5,000 m3 of PCB contaminated soil from the former military facility and dispose of it at the licensed Bennett Environmental Inc. PCB treatment facility in Saint-Ambroise, Quebec. The Bennett contract is worth approximately $7-million.
To meet the requirements of the Canadian Environmental Protection Act (CEPA), and the Nunavut Land Claims Agreement, INAC has prepared an environmental impact statement. A comparison was made between currently available onsite technologies of solvent extraction, thermal desorption and incineration with offsite incineration.
After a thorough review process, the assessment committee -- which included senior management members from INAC Scott Mitchell, Carole Mills and Ricki Hurst, as well as Joanna Ankersmit, Julie Chouinard, Sarah Kalff, and Ed Collins of Environment Canada -- concluded that offsite incineration would be more effective than any onsite solution. In addition, offsite treatment has fewer impacts and risks than thermal desorption or onsite incineration, and is less expensive. According to the impact statement, offsite incineration offers the best combination of low health, environmental, and safety risks, as well as high community acceptance and desirable indirect socio-economic benefits.
"The proposed solution compared to the desorption and washing process would be the option that will remove the highest mass of PCB from the site," said Carol Mills at a public hearing in late September 2000.
The climate and location of the island pose logistical and environmental challenges, which play a part in the selection of a disposal alternative. Access to and from the site is limited by weather conditions, particularly fog, during the field season. There are 196 days of fog per year (on average) that occur mostly in the summer work season. Mother Nature and her unpredictable behavior determine the scheduling.
"Fog can roll in and blanket the entire area, producing extremely low visibility situations in a matter of minutes," explains Harry Flaherty, director of environmental services of QC. "We have no choice but to wait until the fog clears before we can continue work."
Criteria and selection
The impact statement outlines two screening criteria to identify the potential disposal alternatives: proven effectiveness in remediation of PCB contaminated soil and acceptability of the residual risk to human and environmental health both during and after completion of the project.
Of the eight technologies considered, four of the alternatives (chemical treatment, bio-remediation, landfilling and stabilization, and onsite storage) did not meet these two criteria and therefore were not evaluated further. Chemical treatment and bio-remediation are still at an experimental stage. Landfilling and stabilization of material containing PCBs at concentrations above 50 ppm are not legal in Canada. The onsite storage of the PCB contaminated soil is legal, but given the weather conditions and circumstances at Resolution Island, it is not technically feasible.
The impact statement identifies four options that are technically feasible and carry an acceptable residual risk to human and environmental health: thermal desorption, solvent extraction, onsite incineration and transportation of the soil to a licensed treatment facility for disposal.
These options were evaluated based on the following nine criteria:
Onsite thermal desorption was not chosen as the preferred option based on a number of the above criteria. This option concentrates the PCBs into the gas phase and then condenses them into a concentrate. It results in high concentrations of PCBs in relatively mobile and potentially dangerous gas and liquid forms. PCBs in the gas phase are more difficult to contain than PCBs in liquid, which are in turn more difficult to contain than PCBs in soil. The risk of accidents during treatment, handling and transport is higher using this alternative. In addition, onsite thermal desorption produces harmful fugitive emissions of PCBs, hence exposing the environment and the workers to hazardous conditions. Once concentrated, this alternative requires the concentrate to be shipped to a licensed treatment facility to be destroyed. The other drawback identified within the impact statement is the large quantity of fuel that would have to be shipped to Resolution Island and thus create a potential risk in handling, transport and storage.
As with thermal desorption, with onsite solvent extraction the PCBs are extracted and concentrated into a more hazardous form. The concentrated material would then need to be shipped to a licensed treatment facility for final destruction. Again, this would pose a risk during the handling and transportation of the concentrated material. The major limitation noted by the impact statement is that onsite solvent extraction is the least effective method of decontaminating the soil, only achieving a reduction in PCB concentration to 20 ppm.
Onsite incineration was not considered logistically viable. The biggest drawback is the excessive amount of fuel required to operate the incinerator. It would require approximately five million litres of diesel fuel. The potential for fuel spills from the transport, handling and storage, in addition to the need to control and monitor incinerator emissions, make this alternative the one with the highest level of environmental risk.
Following a thorough assessment of the various alternatives, it was determined that transportation to Bennett Environmental Inc.'s licensed treatment facility for disposal involves the least potential for environmental impacts, and the least environmental and heath risks. Bennett, a Canadian company with more than 30 years experience in the environmental industry, is a leading provider of high-temperature thermal remediation for contaminated soil in North America. The company owns and operates the Mark IV Thermal Oxidizer at its waste management centre in St. Ambroise, Quebec.
Transportation of PCB contaminated soil to the facility is the only alternative that completely and safely removes and destroys the PCB contaminated soil. The treatment facility -- which specializes in hazardous waste management -- is continuously monitored and is regularly subject to government inspection. Since the PCBs are not concentrated, the risk to human and environmental health is significantly lower than for any other alternative.
An average of 50 workers -- including engineers, heavy equipment operators, helicopter pilots and cooks -- will be emloyed next season. According to Philippe Simon, a principal engineer from LDS, about half have past experience at DEW Line sites.
Project schedule
The project involves the loading of containers approved for transport from the existing PCB registered storage facility on Resolution Island. The material will be loaded onto trucks for loading and transport to the beach area, approximately 4.4 km away.
The containers will then be off-loaded and transferred to a barge and transported to an ocean-going vessel moored in Brewer Bay. The vessel will travel from Resolution Island to Port Saguenay in Quebec, where the containers will be unloaded from the vessel onto trucks and transported approximately 50 km to Bennett's facility. The PCB contaminated soil will then be treated to destroy all PCB contamination. The project will carry on for three years or until all of the PCB contaminated soil has been transported and treated.
The impact statement was submitted by INAC to the Nunavut Impact Review Board (NIRB) for a full review. INAC and the NIRB held public consultation sessions last fall with the communities of Kimmirut and Iqaluit who are the confirmed traditional users of areas surrounding Resolution Island. The NIRB has submitted its recommendations to the minister for final approval. If all goes according to schedule, this summer will be the first season where PCB contaminated soils are removed from the island and treated at the Bennett treatment facility.
Douglas Kroeker is a project director for Bennett Environmental Inc., based in Toronto, Ontario
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