by David Nguyen, Staff Writer
1. The Randle Reef Contaminated Sediment Remediation Project – Hamilton, Ontario
Cost: $138.9 million
Contaminant: polycyclic aromatic hydrocarbons (PAHs), heavy metals
Approximately 60 hectares in size and containing 695 000 cubic metres of sediment contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals, the Randle Reef restoration project is three decades in the making. The pollution stems from various industries in the area including coal gasification, petroleum refining, steel making, municipal waste, sewage and overland drainage.1
Slated to be completed in three stages, the first stage involved the completion of a double steel sheet-piled walled engineered containment facility (ECF) around the most contaminated sediments, with stage 2 consists of dredging of the contaminated sediments into the ECF. Stage 3 will involve dewatering of the sediments in the ECF and treating the wastewater to discharge back into the lake, and the sediments will be capped with 60 cm of sand and silt enriched with organic carbon. This cap will both the isolate the contaminated sediments from the environment and form a foundation or future port structures. The ECF will be capped with layers of several material, including various sizes of aggregate, geo-textile and geo-grid, wickdrains, and asphalt and or concrete. This isolates the contaminants and provides a foundation for future port structures.
The project is expected to be completed by 2022 and cost $138.9 million. The Hamilton Port Authority will take over monitoring, maintenance, and development responsibilities of the facility for its expected 200-year life span. It is expected to provide $151 in economic benefits between job creation, business development, and tourism.
The Canada–United States Great Lakes Water Quality Agreement listed Hamilton harbour (which contains Randle Reef) as one of 43 Areas of Concern on the Great Lakes. Only 7 have been removed, 3 of which were in Canada.
2. Port Hope Area Initiative – Port Hope, Ontario
Cost: $1.28 billion
Contaminant: low-level radioactive waste (LLRW), industrial waste
The town of Port Hope, Ontario has about 1.2 million cubic metres of historic LLRW across various sites in the area. The soils and materials contain radium-226, uranium, arsenic, and other contaminants resulting from the refining process of radium and uranium between 1933 and 1988. Additional industrial waste containing metals, hydrocarbons, and dried sewage and sludge with copper and polychlorinated biphenyl (PCBs) will also be contained at the new facility.
The material was spread across town as the tailings were given away for free to be used as fill material for backyards and building foundations. An estimated 800 properties are affected, but the low-level radiation poses little risk to humans. The Port Hope Area Initiative will cost $1.28 billion and will include monitoring before, during, and after the construction of a long term management waste facility (LTMWF).
The LTWMF will be an aboveground engineered storage mound on the site of an existing LLRW management facility to safely store and isolate the contaminated soil and material, as well as other industrial waste from the surrounding area. The existing waste will also be excavated and relocated to the engineered mound. Leachate collection system, monitoring wells, and sensors in the cover and baseliner will be used to evaluate the effectiveness of the storage mound, allowing for long term monitoring of the waste.
The facility also contains a wastewater treatment plant that will treat surface water and groundwater during construction of the facility, as well as the leachate after the completion of the storage mound. The plant utilizes a two stage process of chemical precipitation and clarification (stage 1) and reverse osmosis (stage 2) to treat the water to meet the Canadian Nuclear Safety Commission requirements for water discharged to Lake Ontario.
3. Marwell Tar Pit – Whitehorse, Yukon Territory
Cost: $6.8 million
Contaminant: petroleum hydrocarbons (PHCs), heavy metals
This $6.8 million project funded by the governments of Canada and Yukon will remediate the Marwell Tar Pit in Whitehorse, which contain 27 000 cubic metres of soil and groundwater contaminated with hydrocarbons, such as benz[a]anthracene and heavy and light extractable petroleum hydrocarbons and naphthalene, and heavy metals such as manganese. Some of the tar has also migrated from the site.
Contamination began during the Second World War, when a crude oil refinery operated for less than one year before closing and being dismantled. The sludge from the bottom of dismantled storage tanks (the “tar”) was deposited in a tank berm, and over time other industries and businesses added other liquid waste to the tar pit. In the 1960s the pit was capped with gravel, and in 1998 declared a “Designated Contaminated Site.”
The project consists of three phases: preliminary activities, remedial activities, and post-remedial activities. The preliminary phase consisted of consolidating and reviewing existing information and completing addition site assessment.
The second phase of remedial activities began in July 2018 and involves implementing a remedial action plan. Contaminated soil segregated and heated through thermal conduction, which vaporizes the contaminants, then the vapours are destroyed by burning. Regular testing is done to ensure air quality standards are met. The main emissions from the site are carbon dioxide and water vapour. Remediated soil is used to backfill the areas of excavation. This phase is expected to be completed in 2019-2020.
The final phase will involve the monitoring of the site to demonstrate the remediation work has met government standards. This phase is planned to last four years. The project began in 2011 and is expected to be completed in 2020-2021.
4. Boat Harbour – Nova Scotia
Cost: approx.$133 million
Contaminant: PHCs, PAHs, heavy metals, dioxins and furans
The provinces largest contaminated site, Boar Harbour, is the wastewater lagoon for the local pulp mill in Abercrombie Point, as well as the discharge point for a former chemical supplier in the area. Prior to 1967, Boat Harbour was a saltwater tidal estuary covering 142 hectares, but a dam built in 1972 separated Boat Harbour from the ocean, and it is now a freshwater lake due to the receiving treated wastewater from the mill since the 1967.
The wastewater effluent contains contaminants including dioxins and furans, PAHs, PHCs, and heavy metals such as cadmium, mercury, and zinc. In 2015, the government of Nova Scotia passed The Boat Harbour Act, which ordered that Boat Harbour cease as the discharge point for the pulp mill’s treated wastewater in 2020, which allows time to build a new wastewater treatment facility and time to plan the remediation of Boat Harbour.
The estimated cost of the cleanup is $133 million, which does not include the cost of the new treatment facility. The goal is to return the harbour to its original state as a tidal estuary. The project is currently in the planning stages and updates can be found at https://novascotia.ca/boatharbour/.
5. Faro Mine – Faro, Yukon
Cost: projected$450 million
Contaminant: waste rock leachate and tailings
Faro Mine was once the largest open-pit lead-zinc mine in the world, and now contains about 70 million tonnes of tailings and 320 million tonnes of waste rock, which can potentially leach heavy metals and acids into the environment. The mine covers 25 square kilometres, and is located near the town of Faro in south-central Yukon, on the traditional territory of three Kasha First Nations – the Ross River Dena Council, Liard First Nation and Kaska Dena Council. Downstream of the mine are the Selkirk First Nation.
The Government of Canada funds the project, as well as leads the maintenance, site monitoring, consultation, and remediation planning process. The Government of Yukon, First Nations, the Town of Faro, and other stakeholders are also responsible for the project and are consulted regularly to provide input.
The entire project is expected to take about 40 years, with main construction activities to be completed by 2022, followed by about 25 years of remediation. The remediation project includes upgrading dams to ensure tailings stay in place, re-sloping waste rock piles, installing engineered soil covers over the tailings and waste rock, upgrading stream diversions, upgrading contaminant water collection and treatment systems.
6. Sylvia Grinnell River Dump – Iqaluit, Nunavut
Cost: $5.4 million
Contaminant: PHCs, polychlorinated biphenyls (PCBs), pesticides
Transport Canada awarded a contract of over $5.4 million in 2017 for a cleanup of a historic dump along the mouth of Sylvia Grinnell River in Iqaluit, Nunavut. The dump contains metal debris from old vehicles and appliances, fuel barrels, and other toxic waste from a U.S. air base, and is a site for modern day rogue dumping for items like car batteries. This has resulted in petroleum hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, and other hazardous substances being identified in the area.
The Iqaluit airfield was founded in Frobisher Bay by the U.S. military during World War 2 as a rest point for planes flying to Europe. During the Cold War, the bay was used as part of the Distant Early Warning (DEW) Line stations across the north to detect bombers from the Soviet Union. When the DEW was replaces by the North Warning System in the 1980s, these stations were abandoned and the contaminants and toxic waste left behind. Twenty-one of these stations were remediated by the U.S. Department of National Defence at a cost of about $575 in 2014.
The Sylvia Grinnell River remediation project is part of the Federal government’s responsibility to remediate land around the airfield that was transferred to the Government of Nunavut in the 1990s.The contract was awarded in August 2017 and was completed in October. The remaining nontoxic is sealed in a new landfill and will be monitored until 2020.
7. Greenwich-Mohawk Brownfield – Brantford, Ontario
Cost: $40.78 million
Contaminant: PHC, PAC, heavy metals, vinyl chloride
The City of Brantford have completed a cleanup project of 148 000 cubic metres of contaminated soil at the Greenwich-Mohawk brownfield site. The area was historically the location of various farming manufacturing industries that shut down, leaving behind contaminants like PHC, PAC, heavy metals like lead, xylene, and vinyl chloride.
Cleanup began in 2015, and consisted coarse grain screening, skimming, air sparging, and recycling of 120 000 litres of oil from the groundwater, using biopiles to treat contaminated soil onsite with 73% of it being reused and the rest requiring off site disposal.
Barriers were also installed to prevent future contamination from an adjacent rail line property, as well as to contain heavy-end hydrocarbons discovered during the cleanup that could not be removed due to the release odorous vapours throughout the neighbourhood. The 20 hectare site took two years to clean and costed only $40.78 million of the allocated $42.8 million between the all levels of government, as well as the Federation of Canadian Municipalities Green Municipal Fund.
8. Rock Bay Remediation Project – Victoria, British Columbia
Cost: $60 million
Contaminant: PAHs, hydrocarbons, metals
Located near downtown Victoria and within the traditional territories of the Esquimalt Nation and Songhees Nation, the project entailed remediating 1.73 hectares of contaminated upland soils and 2.02 hectares of contaminated harbour sediments. The site was the location of a former coal gasification facility from the 1860s to the 1950s, producing waste products like coal tar (containing PAHs), metals, and other hydrocarbons, which have impacted both the sediments and groundwater at the site.
Remediation occurred in three stages. From 2004 to 2006, the first two stages involving the remediation of 50 300 tonnes of hazardous waste soils, 74 100 tonnes of non-hazardous waste soils, and 78 500 tonnes of contaminated soils above commercial land use levels. In 2009, 250 tonnes of hazardous waste were dredged from two sediment hotspots at the head of Rock Bay. About 7 million litres of hydrocarbon and metal impacted groundwater have been treated or disposed of, and an onsite wastewater treatment plant was used to return treated wastewater to the harbour.
Construction for the final stage occurred between 2014 to 2016 and involved:
- installing shoring along the property boundaries to remove up to 8 metres deep of contaminated soils,
- installing a temporary coffer dams
- draining the bay to remove the sediments in dry conditions, and
- temporary diverting two storm water outfalls around the work area.
Stage three removed 78 000 tonnes of contaminated and 15 000 tonnes of non-contaminated sediment that were disposed of/ destroyed at offsite facilities.
Final post-remediation monitoring was completed in January 2017, with post-construction monitoring for 5 years required as part of the habitat restoration plan to ensure the marine habitat is functioning properly and a portion of the site will be sold to the Esquimalt Nation and Songhees Nation.
9. Bushell Public Port Facility Remediation Project – Black Bay (Lake Athabasca), Saskatchewan
Cost: $2 million
Contaminant: Bunker C fuel oil
Built in 1951 and operated until the mid-1980s, the Bushell Public Port Facility consist of two lots covering 3.1 hectares with both upland and water lots. The facility supplied goods and services to the local mines, and petroleum products to the local communities of Bushell and Uranium City. Historical activities like unloading, storing, and loading fuel oil, as well as a large spill in the 1980s resulted in the contaminated soil, blast rock, and bedrock in Black Bay that have also extended beyond the waterlot boundaries.
The remediation work occurred between 2005 to 2007, and involved excavation of soil and blast rock, as well as blasting and removing bedrock where oil had entered through cracks and fissures.
Initial remediation plans were to crush and treat the contaminated material by low temperature thermal desorption, which incinerates the materials to burn off the oil residue. However, opportunities for sustainable reuse of the contaminated material came in the use of the contaminated crush rock for resurfacing of the Uranium City Airport. This costed $1.75 million less than the incineration plan, and saved the airport project nearly 1 million litres of diesel fuel. The crush was also used by the Saskatchewan Research Council in the reclamation of the Cold War Legacy Uranium Mine and Mill Sites. A long term monitoring event is planned for 2018.
10. Thunder Bay North Harbour – Thunder Bay, Ontario
Cost: estimated at upwards to $50 million
Contaminant: Paper sludge containing mercury and other contaminants
While all of the projects discussed so far have either been completed or are currently in progress, in Thunder Bay, the plans to clean up the 400 000 cubic metres of mercury contaminated pulp and fibre have been stalled since 2014 due to no organization or government designated to spearhead the cleanup.
While the water lot is owned by Transport Canada, administration of the site is the responsibility of the Thunder Bay Port Authority, and while Transport Canada has told CBC that leading the cleanup is up to the port, the port authority was informed by Transport Canada that the authority should only act in an advisory role. Environmental Canada has participated in efforts to advance the planning of the remediation work, but is also not taking the lead in the project either. Further complications are that the industries responsible for the pollution no longer exist.
Industrial activities over 90 years have resulted in the mercury contamination, which range in concentrations between 2 to 11 ppm on surface sediments to 21 ppm at depth. The thickness ranges from 40 to 380 centimetres and is about 22 hectares in size. Suggested solutions in 2014 include dredging the sediment and transferring it to the Mission Bay Confined Disposal Facility, capping it, or building a new containment structure. As of October 2018, a steering committee lead by Environment Canada, Transport Canada, Ontario’s environmental ministry and the Thunder Bay Port Authority, along with local government, Indigenous groups, and other stakeholders met to evaluate the remediation options, as well as work out who will lead the remediation.
