Mine Remediation Barrier Wall

This potash mine located near Regina, Saskatchewan, Canada. Potash mining is a significant industry in Saskatchewan due to the province’s rich deposits of potash, a key ingredient in fertilizers. Potash mining plays a vital role in the economy of the region, contributing to both provincial and national economies through exports and employment. It involves the extraction and processing of potash ore from underground deposits, which are typically found deep underground and accessed through shafts or solution mining methods.
 
The overall goal of these projects was to construct a cutoff wall around the tailing management area of the mine to effectively contain the migration of brine generated by the potash process. This was crucial to comply with Canada’s environmental regulations. This project also focused on mine remediation and contamination mitigation to protect the surrounding environment. 

In the first phase of this project, our team cut the migration of the brine to the adjacent lots while complying with environmental agency requirements. The scope of this geotechnical construction project included excavation of a cut-off wall to 160 feet deep. Due to high groundwater elevation and to maintain trench stability, we added sand to densify the in-trench bentonite slurry and added granular (gravel) material to the soil-bentonite backfill to reduce consolidation. Overall, the mine plans to install about 4.35 miles of cut off wall to contain all the tailings management area and perform groundwater control. This cut-off wall construction was integral to the mine expansion and success. 

This project presented unique challenges in working internationally, especially through the COVID-19 Pandemic. Our team strictly followed all guidelines involving work permits, customs for equipment importation, accounting (currency exchange), and land labor laws.

As part of our project, Forgen worked with the engineer and client to overcome unanticipated higher groundwater elevations causing stability issues. We performed a stability analysis and developed a method to increase the trench slurry density to prevent trench collapse for a safe and successful cutoff wall installation.

The subsequent phase of this project is in progress, with an anticipated completion date in 2025. This phase’s goal will be the successful installation of a 1,500,000-square-foot soil-bentonite cutoff wall to a maximum depth of 160 feet, with concurrent headings used to meet project schedule requirements.

By effectively sealing off the tailings management area with a cutoff wall construction, these projects seek to mitigate the risk of contamination to surrounding land and water sources. Despite facing challenges such as navigating international logistics during the pandemic and addressing unexpected groundwater levels, the initiatives successfully safeguard environmental integrity while supporting safe operational practices for the client and the community.