Source-Controlled Remediation with Combined Geosynthetic and Cement-Based Solidification/Stabilization Systems

The remediation of brownfield sites in Canada represents a serious challenge to the Canadian economy and environment. The federal government of Canada, through the 15-year Federal Contaminated Sites Action Plan, has allocated $3.5 billion to assess and deal with their 21,000 identified sites. Economic and sustainable approaches for remediation of these sites are required; if the cost of a potential remediation project is excessive, the motivation of remediating the brownfield site will undoubtedly be low. Economic spinoffs from this type of work are significant. As noted by The Federation of Canadian Municipalities in 2009, for every $1 invested in brownfield redevelopment, an average of $3.80 is invested in the economy. Mixing contaminated soil with cement is a remediation technique that is gaining traction in Canada; the most recent example being the remediation of 700,000 tonnes of contaminated sediment at the Sydney Tar Ponds Project at a cost of $52 million. Most of this cost relates to purchase of cement. This technique relies on controlling the release of contamination from the site (i.e. source-controlled remediation). However, implementation of this technology in Canada poses several questions: 1) How well will the source-control approach work for cold regions in Canada which undergo freeze/thaw? 2) How can the technology be improved with geosynthetics, yet implemented at lower cost? This research attempts to provide some answers to these questions. Graduate students (1 PhD, 1 Masters) will perform research examining the freeze/thaw hydraulic performance of cement-based solidification/stabilization (CB S/S) treatment of contaminated soil. Others (2 PhD, 3 Masters) will examine the long term suitability of geomembranes and geosynthetic clay liners (i.e. manufactured liner systems) as vertical cutoffs and cover systems for CB S/S systems in order to reduce the cost (i.e. percentage of cement) in the overall remediation system, yet maintain the long-term source-control of contaminants. Each graduate student will receive training in the technical knowledge and professional skills-sets in high demand by Canada's strong engineering services industry.