The development of a brownfield property in Moncton, New Brunswick in Eastern Canada illustrates some of the trends in site remediation – a focus on risk assessment, taking soil contaminants into account in building design, and beneficial re-use of materials.
This property, a former railway yard, had been impacted with a wide range of contaminants due to its previous use. Now, the site has been reborn as the Avenir Centre, a 10,000-seat indoor arena for sports including ice hockey and basketball, as well as cultural events and corporate meeting spaces, which boasts a year-round community gathering spot on beautifully landscaped grounds.
In support of this development, Golder worked with the City of Moncton, the provincial government and the general contractor to help make the site environmentally safe for its new role.
Golder’s work on the site began with several Environmental Site Assessments (ESAs) to study the contaminants in the soil, groundwater, and soil vapour. The ESA work helped guide development of the property, managing the health and environmental risks while also pointing to cost-saving opportunities. This led to developing a Risk Management and Remediation Action Plan detailing the risk management measures to be taken, as well as a Soil and Groundwater Management Plan.
A human health and ecological risk assessment developed site specific target levels (SSTLs) for contaminants of concern for the intended commercial and residential land use. These SSTLs recognized the need for risk management for the inhalation pathway (naphthalene and tetrachloroethylene (PCE)) and direct contact pathway (Benzo[a]pyrene Total Potency Equivalents (B[a]P TPE) and lead).
The risk assessment found that the property would be environmentally safe for the intended end use, as long as proposed risk management measures were implemented. Those measures included encapsulation with a hard cover surface and a sub-slab soil vapour extraction system inside the building.
Golder’s work on the location of soil contaminants meant that the Avenir Centre’s utilities and underground structures were positioned, where possible, in uncontaminated areas to minimize contaminant disturbance. This helped reduce site workers’ exposure to health hazards. Segregating soil based on contamination concentrations also significantly reduced export of excess soil. Some of the excess soil with low contaminant concentrations found a beneficial use within city limits as part of a berm that would reduce noise impacts of trucks and heavy equipment at a City snow disposal site.
The soil vapour intrusion mitigation system in the Avenir Centre, designed by Golder, protects the building’s indoor air from contaminants in soil and groundwater. Golder monitored the vapour system’s installation under the ice surface and building footprint and supported the system’s commissioning. To reduce operation cost and effort, the vapour intrusion mitigation system is connected to the building automation system for real-time monitoring.
The Avenir Centre is a modern, state-of-the-art facility, but more than that, it has been a boon to the local economy. Hundreds of full- and part-time jobs have been created to support the centre and local businesses, a new Hyatt hotel is under construction next door, and the downtown area has experienced a 100% increase in new development projects.