In-Situ / Ex-Situ Remediation

Terrapex has extensive expertise and experience in environmental remediation. Depending on the requirements of our clients, Terrapex will provide remediation services on either a turn‑key or a supervisory basis. 

Our involvement in remediation projects has ranged from third party reviews, the completion of detailed or preliminary environmental assessments, through to the implementation of the remedial action plan including liaison with regulatory bodies, remedial option/feasibility studies, public consultation, tender documents preparation, and construction supervision. 

Our multi-disciplinary team of engineering, geoscience and environmental specialists have expertise and experience in a range of in situ and ex situ remedial approaches including excavation/removal of contaminated soil or other media, groundwater pump and treat systems, vapour extraction, biostimulant injections, and natural attenuation. 

In Situ Remediation

In situ (“in place”) remediation refers to the cleanup of contaminated soils and groundwater without removing contaminated media from the subsurface, typically through the use of physical and/or chemical processes.

Terrapex has considerable experience and expertise in employing numerous in situ technologies, including:

• biostimulation through the addition of chemical additives to enhance or stimulate natural microbial processes;
• chemical oxidation through the injection of potassium permanganate, calcium hydroxide, and other reactive slurries into the subsurface;
• bioremediation via injection of highly oxygenated water or oxygenated gases into the subsurface;
• vapour extraction to remove vapour-phase contaminants in the subsurface by volatilization of volatile contaminants for subsequent recovery;
• construction of hydraulic barriers to mitigate migration of soluble contaminants;
• groundwater flushing via injection and recovery of surfactants; and,
• pumping/extraction systems for recovery of immiscible and dissolved‑phase contaminants.

In practice, the successful application of an in situ remedial is dependent upon the innovative combination of several in situ remedial technologies.  The selection, design, and operation of such systems can only be achieved through the collaborative efforts of experienced and knowledgeable engineering and scientific experts.

Terrapex’s multi-disciplinary approach has resulted in the successful design and operation of numerous in situ remedial systems in locations ranging from well‑developed urban areas to un‑serviced rural and remote areas.

Ex-Situ Remediation

Unlike in-situ approaches, ex-situ remediation involves the removal of contaminated media, either for off-site disposal or for on­‑site treatment and subsequent return to the subsurface.

Our team of engineering, geoscience and environmental specialists have considerable experience and routinely employ a variety of ex-situ methods, the most common being:

• excavation and off-site disposal of impacted soils (with on-site segregation/management of contaminated soils from uncontaminated soils);
• the construction and operation of biopiles (both aboveground and subterranean); and,
• recovery and treatment (if required) of impacted groundwater.

 
Mobile Certificates of Approval

Terrapex has obtained mobile Certificates of Approval (Cs of A) for many of the remedial technologies/approaches we routinely use at contaminated sites.  These Cs of A permit our clients to commence in situ and ex situ remedial programs that would normally require the completion of a lengthy Ministry of the Environment approval process, in as little as ten days.

Our mobile Cs of A have been purposefully written to permit a high degree of flexibility of use, to ensure that the remedial approach is determined by technical requirements and not by the limitations of the C of A. 

While we have had considerable success employing our mobile Cs of A, Terrapex is not committed to any single technology.  Instead, our approach is to consider the best alternative for the property taking into account technical applicability, as well as cost, schedule, and other client/situational requirements.