Sydney Tar Ponds Remediation Project

Sydney, Cape Breton Island, Nova Scotia

Photo Credit: NS Lands Inc.


Research by: Samantha Miller

Edited by: Nicole Brekelmans

Case study compiled in 2019



Project: Sydney Tar Ponds Remediation Project / Open Hearth Park

Type of Urban Strategy: Green Cities, Industrial Landscapes, Indigenous

Type of ProjectSite Remediation

LocationSydney, Cape Breton Island, Nova Scotia

Date Designed/Planned: 2004

Construction Completed2014

Designer: Stantec, AECOM


The Sydney Tar Ponds was a massive project that changed the city of Sydney, Nova Scotia. The Sydney Tar Ponds Agency had a vision for a project that would end up being a $400 million project. The project intended to clean up the site of an old steel manufacturing site and Coke Ovens site, while not losing sight of its history. After over 100 years of steel production, the site was extremely contaminated by chemicals and metals, so much so that they had to close lobster fishery operations due to contaminated waters. The government of Nova Scotia was receiving criticism for not having addressed the contamination situation, so they partnered with the Sydney Tar Ponds Agency to clean up the site and transform it into an active and passive recreation park in the heart of Sydney. “The goal of the planning exercise was to prepare a phased land use plan that is logical and achievable, but is also visionary and transformative,” said Gary Campbell, President of Nova Scotia Lands Inc. “When it comes time to implement, the plan should leave a lasting legacy for the entire region”… Along the channel will be walking paths, new roads, sidewalks, bridges, commercial expansion along the SPAR road, and new infrastructure that will merge Whitney Pier with downtown Sydney” (Canadian Business Journal, 2011). The journey of this project and its evolution from years of steel manufacturing that affected the current residents of Sydney and the Indigenous people, whose lives have been greatly impacted by the production site. After the site was abandoned with Tar Ponds and tons of contaminated land, the government of Canada along with the government of the province of Nova Scotia made this project a priority because they knew that it was one of the largest contaminated sites in Canada and they were putting their citizens and workers at risk. The park today does not diminish the heritage of what the site once was, but gives Nova Scotians a beautiful park in the heart of their city with plenty of programmable and leisure space, that celebrates the history of Sydney. 


“The Tar Ponds and Coke Ovens are the vestiges of days gone past, when Cape Breton had one of the world’s largest steel plants. Very soon, the only signs of Cape Breton’s steel and coking industry will soon be the educational signs set up along the forest path along the Creek. The Sydney Tar Ponds Agency is making sure of it” (Canadian Business Journal, 2011)


Located in Harbourside Commercial Park in the city of Sydney, Nova Scotia in Cape Breton Island. This project was an attempt to remediate the location of the Tar Ponds and Coke Oven sites in which there were over 747K cubic meters of contaminated soil (PWGSC, 2014). This contamination was a result of almost a century of steel production on-site, causing the Commissioner of the Environment and Sustainable Development to criticize the federal government in 2002 for not having addressed the site thus far. Some of the approaches to remediating the site included using a technique known as solidification/stabilization (mixing Portland cement with small units of contaminated material), taking contaminated material off-site to be solidified/stabilized, provisioning surface and groundwater controls, and the installation of a surface cap (PWGSC, 2014). The site was ultimately turned into a park, that has helped improve the area’s future, providing better health benefits in terms of quality of life and provides essential social returns (AECOM, n.d.). The site is now the home of Open Hearth Park, a 39-hectare green area which includes a sports field, walking trails and playground (CBC News, 2013).


One of Canada’s largest contaminated industrial sites, The Sydney Tar Ponds and Coke Ovens Sites were heavily contaminated after more than 100 years of steel production. In this time, the process of coke production resulted in a soup of deadly chemicals and heavy metals such as mercury on-site. There was mover 1.1 million tons of impacted by the contaminated soil. The contamination was spread out over three significant sites in the area, including the North Tar Pond, the South Tar Pond, and the former Coke Ovens Site (100 hectares of land). The site is surrounded by an urbanized setting, and is amongst a complex estuarine and marine environment (AECOM, n.d.). After extensive site analysis, the Coke Ovens site revealed to be contaminated primarily with petroleum hydrocarbons, PAH’s, metals and other byproducts resultant from the coking process. The groundwater on the Coke Ovens site was contaminated with metals and DNAPLs (dense non-aquatic aqueous phase liquids), along with its location being very close to local residents, endangering them (Sydney Tar Ponds Agency, 2008). The Tar Ponds revealed to be receiving an industrial discharge from activities upstream and was contaminated with PAH sediments, and sediments with 50+ ppm PCBs, and metals. The North Pond was always underwater as a tidal estuary, with several sewer outfalls. The South pond was also a tidal estuary, being fed by two significant surface water flows (Sydney Tar Ponds Agency, 2008).


The Sydney Harbour has been the site for a large coking and steel manufacturing facility that was in operation from 1901 until it was closed in 2001. The Sydney Tar Ponds were formed as a result of thousands of tons of contaminants migrating via the Coke Ovens Brook Connector into the Muggah Creek, and via the creek and ground water into the tidal estuary that forms the mouth of the creek, where they built up and created sludge ponds. The Fisheries and Oceans Canada were forced to shut down their lobster fishery operations in the Sydney Harbour in the 1980s due to the contaminated water that was migrating from the site. They found that not only the waters and soil was contaminated with numerous chemicals and metals, but that odours were also flowing out from the site as a result of the contamination. The federal government acquired ownership of the steel plant and Coke Ovens in 1986, where they operated the facilities as the Cape Breton Development Corporation until the Sydney Steel Corporation purchased the site in 1973. The Sydney Steel Corporation was receiving funding from the federal government that allowed it to continue operating until 2001. A cleanup initiative began in an agreement between the federal and provincial governments in 1986, but the project was ultimately unsuccessful due to economic and technical issues. In 1996, the Province came up with a subsequent proposal to bury the contaminants under slag, but the community was unhappy about the idea, and so the project was dropped. After this, in the same year, the Joint Action Group, which is a community-based advisory group, was established, and they recommended a cleanup method. In 1998, the JAG, along with the federal, provincial, and municipal governments, signed a Memorandum of Understanding which established a framework for participation in the cleanup. The federal government was receiving criticism from the Commissioner of the Environment and Sustainable Development for their lack of effort in cleaning the site and naming it among Canada’s worst sites. After this debacle in 2002, the Federal budget committed $500 million in 2004, for remediation activities in Canada for ten years, prioritizing Sydney. In April of 2004, the federal government approved their support for the STPCORP (Sydney Tar Ponds and Coke Ovens Site Remediation Project). (PWGSC, 2014)


The goal of the project was to remediate the site, in hopes to provide the city with a big, beautiful space for active and passive recreation in the heart of the city. They also hoped not to lose sight of what the site used to be, with forest trails with interpretive panels and signage that speak to the legacy of the steelmaking and coke oven production (The Canadian Business Journal, 2011). The Joint Action Group (JAG) aimed to seek consensus in the community on a safe, technically-sound cleanup solution, that would best benefit the people of the province and the land itself. JAG put provided over 100,000 volunteer hours, with 950 public meetings over 7 and a half years, to ensure the community was on board with the project and that it was catered towards the needs of the people and the environment (The Canadian Business Journal, 2011). The Sydney Tar Ponds Agency outlines their vision was to be recognized internationally for the excellence of cleaning up the site, and converting it into a community asset. They wanted to keep the health and safety of the community and works as the number one priority and maintain an ethical, communicative and professional process (Sydney Tar Ponds Agency, n.d.).


The team decided to use the technology of Solidification & Stabilization (S/S) because it is a safe treatment, management and reuse strategy for contaminated waste. This technique involves mixing cement such as Portland Cement in this case, with contaminated material which immobilizes the contaminated material within the treated material. This technique prevents hazardous materials from escaping into the environment, and it has proven to be very successful in contaminated sites. They also designed for the flow of brooks and groundwater to be redirected during the remediation process, so that it can be released after the material has been treated, but with an engineered cap so that the treated material has extra protection. Groundwater is collected and treated on the Coke Ovens site through underground pipes, where it is taken to the on-site treatment plant to be turned into freshwater and emptied into a nearby brook. An Environmental Management Plan (EMP) was put into place to ensure that the project minimizes its potential environmental impacts, and communicates its efforts to the stakeholders and the public to fall in line with their vision to be transparent and communicative. They also partnered with the Air Monitoring Program in Sydney, to ensure that the contractors and workers are provided with all of the information and preventative measures that they may require. The project also has a Master Health and Safety Plan that further protects workers and the public from any risks that the project had. (Tar Ponds Cleanup, n.d.). In terms of the design of Open Hearth Park, Stantec looked at the site and the cap material that was put in place and thought for sure that the park would have to be flat. But they wanted to use landforms to create visual interest, so they collaborated with the remediation specialists and structural engineers to reinforce areas in the park, to allow more options for creativity. They used some of the abundant local slag to experiment with and create opportunities. They built raised planting areas for deciduous and evergreen trees, which provided space for the tree’s roots to expand and grow. They were able to use the slag on site, which meant they did not have to ship any materials to the location, saving on project costs in the long run, and reducing the carbon footprint. The topography that was created after this process is unique and provides support for a diversity of native vegetation, as well as interest and beauty. The park’s resilient landscape helps to manage stormwater, and provides wildlife with plenty of natural habitats; stormwater management included vegetated swales, leading water off-site. Stantec understood that there is a heritage of Indigenous peoples on the land, and the steel plant shaped their lives. They consulted with local artists to hear about the story of the Indigenous peoples on this land and then developed a collection of themes that were shared with the art community. The artists then submitted their interpretation of the themes that Stantec put forward, and a committee selected pieces of sculptures, mosaics, educational signage, and salvaged relics that would best reflect the design theme, provide context and celebrate the rich Indigenous history. (Stantec, n.d.)


Sydney Tar Ponds Agency turned to AECOM to develop a remediation design strategy, to support the agency’s vision of completing this project with sustainable principles of remediation. AECOM was responsible for managing the remedial design and construction, and administration services. They ensured that the clean-up work was as sustainable as possible, by using the use of local materials, and they managed construction sequencing, transportation and handling of project materials to ensure that they reduced air emissions, site impacts (erosion control, demolition activities) and offsite waste disposal as much as possible (AECOM, n.d.). AECOM identifies the benefits the client received by using them for this project: “Client Benefits: -Identified a new risk factor to the project budget and schedule -Innovative, alternative approach to sediment stabilization allowed the project to stay on time and on budget -Successful transition from the Design to Construction phase.” (AECOM, n.d.) Stantec designed the park that is currently on-site, Open Hearth Park.


AECOM | Sydney Tar Ponds. (n.d.). Retrieved July 16, 2019, from[0]=205&qp=&qt=12 Canada, Province of Nova Scotia. (2006). Joint Review Panel for the Sydney Tar Ponds and Coke Ovens Sites Remediation Project (Canada). Library and Archives Canada Cataloguing. Retrieved July 16, 2019, from Canada, Public Works and Government Services Canada, Office of Audit and Evaluation. (n.d.). Final Evaluation of the Sydney Tar Ponds and Coke Ovens Remediation Project(2013-602). Retrieved July 16, 2019, from Canada, Public Works and Government Services Canada, Office of Audit and Evaluation. (2006, December 8). Government of Canada. Retrieved July 16, 2019, from Larkin, R. (2008). Sydney Tar Ponds & Coke Ovens Remediation Project, Remediation Technologies Symposium, Banff, Alberta, October 15-17. 2008. Sydney Tar Ponds Agency, accessed on July 15, 2019 from NS Lands Inc. | Open Hearth Park. (n.d.). Retrieved July 16, 2019, from Remediated Sydney tar ponds unveiled as green space. (2013, August 30). CBC News. Retrieved July 16, 2019, from Stantec | Open Hearth Park. (n.d.). Retrieved July 16, 2019, from Sydney Tar Ponds Agency | Mission and Vision. (n.d.). Retrieved July 16, 2019, from Sydney Tar Ponds Agency. (n.d.). The Canadian Business Journal. Retrieved July 16, 2019, from
Tar Ponds Cleanup. (2011). Sydney Tar Ponds Agency[Brochure]. Retrieved July 16, 2019, from


The local community benefited immensely from this project, in terms of socio-economic benefits. $180 million was directly expended in the Cape Breton region, of which $71 million was awarded to First Nations firms, much more than the targeted goal ($19 million). Now, the site can be used for recreation and light commercial/industrial purposes, which has directly impacted and improved the quality of life of the community. The Public Works and Government Services Canada, Office of Audit and Evaluation has found that this project has dramatically removed the stigma around the Tar Ponds Area, which has improved community cohesiveness and enhanced business prospects and community attractiveness (PWGSC, 2014). The project has received numerous awards and recognition, such as the Canadian Urban Institute Project of the Year (2012), Environmental Business Journal project merit award (2013), and more (AECOM, n.d.).


One of the obvious challenges was the contaminants in the site and the risk that is associated with public interest and safety. The site is situated within the heart of Sydney, Nova Scotia, within four kilometres of more than 25,000 people. The site poses apparent risks to the environment and the people around it, meaning that the action that it required had to follow national contaminated site guidelines. The PWGSC mentions a challenge in terms of media scrutiny, saying that “the public and environmental and citizens’ groups have been highly sensitive to the activities undertaken and are generally either highly supportive or intensely critical of all levels of government” (PWGSC, 2006). AECOM was faced with the most challenging task of cleaning up one of Canada’s largest contaminated industrial sites, meaning the entire project was a challenge in itself (AECOM, n.d.). A future challenge poses itself, as the method used in remediating the site aren’t proven to be long term solutions. Residents of Cape Breton and people from across Canada are skeptical of the project, saying that they’ve only done a cosmetic cleanup making it look like it’s all gone, but the chances that the toxic materials are gone for good are slim to none (CBC News, 2013).


Before this project, there were a few attempts at remediating this area, although they were unsuccessful. During these unsuccessful attempts, extensive public consultation and technical studies were completed, allowing the final project to have some information and trial and error studies, to begin with. The final cleanup plan was announced in January of 2007 (Canadian Business Journal, 2011). The STPA immediately began with preventative works, including constructing a barrier at the mouth of Muggah Creek at Battery Point and diverting streams that were flowing through the sites at the time. The Joint Review Panel of Environmental Assessment Report highlights the panels concerns and the recommendations they made for moving forward with the project (Province of Nova Scotia, 2006).


Open Hearth Park now includes a park facility for people of all ages with paved pathways winding through the park for recreational walking. There are a variety of trails for running practice and organized runs can be hosted. Natural open spaces provide areas for family gatherings and recreation, as well as for casual sports. There is also a playground intended for play of children aged 3-12, with foam padded surface play areas, slides, ramps and netting, stationary music instruments, and a water play environment (NS Lands Inc., n.d.).


The Final Cost-Share Agreement provided an outline for a budget for the project. The budget of $397.7 million was established, and the federal government committed to providing $277.7 million, and the provincial government committed to providing $120 million. The final cost of the project was $8.4 million below the Cost-Share Agreement, due to the engineer’s design suggestions and improved efficiency of remediation activities (PWGSC, 2014).