- The Evolution of the Contaminated Site Remediation Industry in Canada
Our industry has experienced a steady evolution since the “dig and dump” days with advances in science, technology, regulation and societal trends (like sustainability). The early approach of soil excavation exclusively for metals has evolved, as remedial designs now consider hundreds of contaminants in soil, groundwater and vapours at concentrations as low as in the parts per trillion range. Additionally, our greater understanding of the subsurface has resulted in the need to consider complex processes such as vapour intrusion and diffusion-controlled migration.
With over 30 years of experience in environmental consulting and remediation contracting, the author will provide several insights on the issue, by discussing advances in the characterization of site conditions, better engineered remedial amendments (including activated carbon-based), application technologies, and the use of interim data collection to assist in optimizing remedial programs.
Reviewing the past provides environmental practitioners and stakeholders a more thorough understanding of the state of remediation in Canada, what is possible, what is not, and what the future of our essential sector may hold.
– Causes and Cures for cDCE Stall: Lessons Learned in 30 Years of Enhanced Reductive Dechlorination
Enhanced Reductive Dechlorination (ERD) has developed into a reliable and robust technology for in-situ treatment of PCE and TCE. However, at too many sites, DCE and VC conversion to ethene is rate limiting, increasing the time and cost to meet remediation goals.
Common causes of slow DCE conversion to ethene include absence of Dehalococcoides, competitive and/or toxic inhibition by other CVOCs, absence of substrates that can be fermented to hydrogen, low nutrient levels (N, P, B12), and low pH.
In this presentation, we will review the microbiology of DCE reduction to ethene and strategies for accelerating complete dechlorination to non-toxic end products.