April 9th, 2014 AEL environment
On remote sites, like those in Canada’s Far North, the cost of traditional remediation can be astronomical. Because these sites are often beyond the access of landfills, soil transport and disposal can make traditional “dig-and-dump” remediation too expensive to pursue. For this reason, AEL believes that remote sites are often ideal locations for choosing alternative strategies such as risk assessment.
Risk assessment (RA) is simply the evaluation of risk that any given impacts on a site have on human, animal, and environmental receptors, and using risk management strategies to bring those within a site-specific acceptable range, as decided by regulatory officials.
By utilizing RA as a remediation approach, the amount of soil that must be transported off-site can be minimized or eliminated. Using other risk management measures allows RA to be a completely viable, compliant, and appropriate solution for many sites, especially those in remote locations.
Another way that AEL minimizes remediation costs is through the use of on-site remedial technologies like sifting to remove inert material like rocks and concrete from soil that requires disposal. By separating these bulky components, which are not impacted by contaminants, the soil volume can be reduced by up to 95%. AEL’s use of on-site testing also helps in this area, as impacts can be clearly delineated and the team is able to see exactly which soil can remain on site.
Sifting and on-site testing were used on a remote site in northern Quebec to save a client approximately $200,000. Within a very short work season, AEL was able to quickly delineate the impacted soil, determine contamination volumes, and remediate the site.
AEL investigations at the site were able to delineate copper contamination present at the site and AEL therefore was able to recommend remedial approaches for the site. Due to the large volume of impacted material and difficult access to landfill, AEL explored alternative remedial technologies and selected pre-screening of the impacted soils because of the large volume of rock in the soil. A 1/2” screen was used and any material that couldn’t go through the screen was separated. The soil that went through the screen was tested and either disposed of or used as clean fill, based on the on-site testing results.
By screening the copper impacted material on site, and returning “clean” material for reuse (mostly rock), project engineers were able to reduce the material shipped off-site for disposal to less than 100 m3, at a net savings of approximately $200,000.
Remote sites are often too isolated to complete traditional excavation/disposal remediations.