In Quebec, an initial project was carried out in 2009–2010 to rehabilitate the Corbec industrial site in Montreal. The cement-based stabilization-solidification technique was used to process contaminated soils with heavy metals (zinc).
Groupe Vespo Inc., an excavation company, built a new office building and a garage on the land of a former galvanization plant located in the area around the Lachine Canal in Montreal. The 17,000-square-metre parcel of land had been contaminated with zinc used by the former plant. In some areas, zinc concentrations measured 20,000 ppm, whereas the Ministère du Développement durable, de l’Environnement et des Parcs du Québec (MDDEP) recommended that background levels not exceed 1,500 ppm (Criterion C). Zinc had contaminated the water table.
The client and consultant took four remediation techniques into consideration from the perspective of a cost and feasibility analysis: excavation and disposal in an approved disposal site; confinement using bentonite walls; confinement using waterproof membranes (not authorized by the MDDEP for this project); and cement-based stabilization-solidification on site. This final option proved to be the most economical and safest method.
The process included excavating contaminated soils, screening large aggregates and applying the cement-based SS treatment using a Pugmill plant. All materials treated in this way were re-used on site and served as the base for a parking lot in the industrial sector. More than 11,000 cubic metres of soil were treated on site using the SS method.
To assess the feasibility of the SS project for rehabilitating the site, an in-depth study was conducted by the Groupe Qualitas in cooperation with the École de technologie supérieure (ÉTS) and Ciment Québec. The study included a laboratory phase and pilot phase on the site, which was completed in 2009. Physical and chemical tests were conducted to evaluate the performance of SS treatment.
The feasibility study, laboratory tests and pilot project allowed us to treat contaminants on site using the SS technique. All physical and chemical tests complied with MDDEP requirements. The pilot project confirmed the feasibility of using large-scale SS treatment (excavation, screening, mixing, and application). The rehabilitation plan was approved by the MDDEP. The entire project was finished in November 2010.
Owner: Groupe Vespo Inc. — Montreal
Engineers: Groupe Qualitas Montérégie — Division of SNC-Lavalin
Contractor: Groupe Vespo Inc. — Montreal
Partners: École de technologie supérieure (ÉTS) — Montreal and Ciment Québec Inc.