Harvey Barracks Remediation
Most engineering projects involve bridges or structures that enhance our physical well-being. Other projects, however, result in bridges of trust established between different communities that are jus...
Most engineering projects involve bridges or structures that enhance our physical well-being. Other projects, however, result in bridges of trust established between different communities that are just as important as many physical structures. This project was an eight year journey wherein the Government of Canada worked with the Tsuu T’ina First Nation to restore lands that had been affected by 80 years of military use.
Golder Associates, as the independent consultant, often acted as the link between the government and the First Nation, helping to build trust by establishing appropriate ways of assessing the site, ways of remediating the problems and of verifying that the remediation was effectively carried out. The project demonstrates how goodwill brokered by implementing appropriate engineering and scientific processes can achieve substantial community benefits.
A large and complex site
Consisting of over 380 hectares of land in southwest Calgary, the reserve land formerly known as Harvey Barracks was used by the Department of National Defence from 1919 to 1997 for a variety of military training.
In 1991, the Department agreed to return the land to the Tsuu T’ina First Nation, who plan to use part of the property for residential development. Since the land was an integral part of the Tsuu T’ina heritage, it was important that the clean-up project showed respect for the land and dealt sensitively with the impact on archaeological sites and other resources that are important to the First Nation’s tradional culture and values.
Geographically, the site is approximately triangular in shape. It is bounded by the Glenmore Trail to the north and to the south by a natural reach of the Elbow River, just upstream of the Weaselhead natural area.
The site restoration was a large, complex project that posed a number of technical challenges. The land had been used for firing ranges and military training for demolition dumps and solid waste landfills. It also contained buildings and maintenance areas. The potential hazards ranged from physical (unexploded ordnances) to chemical (potential existence of chemical weapons or their residue). The cost for remediation was in excess of $70 million.
The scope of the multi-year program was staggering. A total of 3,330 test pits were dug. Almost 300 borings were drilled. Eighty-two monitoring wells were installed. Over 11,000 soil samples were sent for analysis. The requirement that the land be returned to a level suitable for residential use was taken very seriously by all sides.
How clean is clean?
Various areas were considered high risk and required extraordinary health and safety measures to protect the working crew. For example, the possibility of encountering unexploded ordnance necessitated the use of specially designed armour-plated and remote-controlled backhoes.
The issue of “How clean is clean?” is a problem on many clean-up sites. Over the years the Canadian Council of Ministers of the Environment has developed standards for the clean-up of soils impacted by commonly used chemicals. This site, however, had conditions that fell outside the typical standards. For example, what are the criteria for chemically inert but physically imposing waste and debris? What characteristics of this material make it appropriate for residential use? Golder Associates worked with the stakeholders to establish criteria (size of particles, depth, density) that could be consistently implemented. Spent bullets posed a different concern — primarily because they contain metals such as lead, copper, and zinc. Golder developed a “probabilistic risk assessment analysis” of the risks associated with children’s exposure to lead fragments. The assessment involved biological laboratory tests that simulated human ingestion. It is believed to be the first time an analysis of this kind has been done to make informed risk management decisions.
Another major issue was the potential impact of the site’s unknown constituents and chemicals on the environment. Golder Associates’ subsidiary company Hydroqual Laboratories developed a series of biological tests to quantitatively assess the capability of the soil to support the appropriate biological activity for the area. This testing suite incorporated biological, chemical, and physical data into a single value. The results allowed for the parties to agree on remediation strategies and how to optimize costs.
The environmental assessment and remedial work was completed in the fall of 2004. As part of their terms of reference, Golder certified the land as suitable for residential land use.
Organizing the data
Over 200,000 pieces of data were collected and stored over the course of the project. This extraordinarily large database was integrated with a Geographic Information System (GIS) and an orthophoto mosaic to produce the information in mapping and graphical formats. The visualizations proved to be a powerful tool for explaining situations to the diverse group of stakeholders, giving everyone a consistent understanding of the project and thereby helping in the decision making.
A project of this size and duration creates a large number of reports, recommendations and remediation certificates. Golder created a legacy CD of the project with interactive databases and printable versions of all reports. Feedback has been very positive in that the digital resource provides intuitive access to the information and has allowed users to answer questions that have arisen.
Name of Project: Harvey Barracks Environmental Remediation, Calgary
Award-winning firm: Golder Associates, Calgary (J.H.A. Crooks, P.Eng., M.A. Brightman, P.Eng., D. Simpson, P.Eng., M. Bauer, P.Eng., J. Graves, EIT, C. Hardy, P.Eng., D. Pritchard, P.Eng., K. Beneteau, P.Eng., R. Robinson, Ph.D., A. Cole, P.Eng.
Owner & client: Department of National Defence; Tsuu T’ina First Nation